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Valve Expert 4.x (user manual) - English

1. 9 INTERFACE ELECTRONICS 11 ALARM INDICATORS OF THE 12 GOMPUTER SUBSYSTEM rat 13 MOTOR EIS CTETUR 14 DATA ACQUISITION ELECTRONICS 15 AMPLIFIER FOR PROPORTIONAL DIRECTIONAL CONTROL 5 15 SERVOVAL VE INSTAEEATION 19 SOFTWABE ee a aon re a eae ee a 22 VIRTUAL LABORATORY 22 HYDRAULIC POWER 24 UNIVERSAL AMPLIFIER 2 9 8 0 252 22 95 25 THE MAIN GONTROL ECT M M 25 HYDRAULIC CONFIGURATIONS 26 MEASUREMENT INSTRUMENTS wasuncccecccecececnccnnecnsnsnsncecncnnsnsnenensnsanennennnnsn
2. Control pressure B Pressure test 2221 Leakage Pressure test Hydraulic schema 2 0 EINEN Spool position Pressure test zm Flow test gt dest Cia E Not required A03 pastor Flow test 4 R ests 5 0 5 F p Phase lag j zs led test Amplitude ratio Step response 2 Safe Position Test Made tests 7 02 Te Teed eR TE eS Re ee IL Sh Te am bah oan Pay pepe me lees fae ool os Te ee on og oa a od A ees ee UL ng Se on Dp eat Doe ee ee ee ee 20 0m 40 0m 60 0m 80 0m 100 0m 120 0m 140 0m 160 0m 180 0m 200 0m Time sec Plot name Step response Pressure Leakage test Heater Cooler L H Control Degaussing amp i00mA g Coi2 g 100 125 150 100 100 s cfg cfg 0 i 20 iso 2 5 Alarm system 75 7 175 i Signal 80 Bi 80 3 A Coil 1 5 2 3 Ge 4 20 mA 502 2200 60 60 3 a 5 F t Reset 32 20 m 2570 27225 Power Motor 40 402 Generator A 2 Feedback Polarity Parallel 2 4 2 5 10 m 0 250 202 202 4 2 22 1 100 bar 2 1 0 v 1 1 10 Serial Figure 62 Preliminary Pass Fail evaluation Printout of the Results A powerful report generator is integrated into the system ValveExpert This generator puts measured data to a Microsoft Exc
3. INPUT CURRENT INPUT CURRENT CONTROL FLOW Figure 75 Normal Flow Curve The locus of the midpoints of the complete cycle flow curve which is zero hysteresis flow curve Usually valve hysteresis is sufficiently low such that one side of the flow curve can be used for the normal flow curve See Figure 76 DIETZ automation GmbH 56 M V Shashkov CONTROL FLOW NORMAL FLOW CURVE RATED CURRENT INPUT CURRENT F INPUT CURRENT RATED CURRENT j BIAS 9 zi Figure 76 Flow Gain The slope of the control flow versus input command curve in any specific operating region expressed in l min A gal min V etc Three operating regions are usually significant with flow control servovalves 1 the null region 2 the region of normal flow control and 3 the region where flow saturation effects may occur Where this term is used without qualification it 1s assumed to be defined by the region of normal flow gain See Figure 77 SATURATION REGION 2 NORMAL REGION CONTROL FLOW INPUT CURRENT 1 NULL REGION EXAGGERATED NORMAL FLOW CURVE Figure 77 DIETZ automation GmbH 57 M V Shashkov Normal Flow Gain The slope of a straight line drawn from the zero flow point of the normal flow curve throughout the range of rated current of one polarity and drawn to minimize deviations of the normal flow curve from the straight line
4. Max Maximal value Analysis of the Spool position Curve e Spool Position 4 Test The curve belongs 1 or does not belong 0 to the overlay region Line SP4 x0 Coordinate 0 of the linear approximation Line SP4 x1 Coordinate x1 of the linear approximation Line SP4 y0 Coordinate yO of the linear approximation Line SP4 y1 Coordinate y1 of the linear approximation Hysteresis SP4 Hysteresis Nonlinearity SP4 Nonlinearity SP4 Min Minimal value S P4 Max Maximal value Measured Data e Control Values of the control signal DIETZ automation GmbH 50 M V Shashkov Feedback Values of the spool position transducer Flow B Values of the flow between ports and Feedback Overlay Control x values of the overlay curves e Feedback min y values for low limit overlay curve Feedback max y values for high limit overlay curve Flow B Overlay Control x values of the overlay curves A min y values for low limit overlay curve Flow A max y values for high limit overlay curve Dynamic Test Excel Sheet Dynamics Test conditions Supply Pressure System pressure e Offset Offset of the control signal Amplitude Amplitude of the control signal Analysis of the Phase Lag Curve e Phase Lag Test The curve belongs 1 or does not belong
5. control 5v 100 5v 100 control 4 d T tank Volks Software IVT Drivers e Remote Systems HI DAGOmx Scale Figure 70 Measurement amp Automation Explorer from National Instruments Mathematical Analysis Linear Analysis In order to get the most of static parameters like Hysteresis Pressure Gain Flow Gain Bias Non Symmetry Non Linearity Overlap and so on the test equipment ValveExpert makes the linear analysis I will illustrate the algorithm of this analysis on a graphic of the flow curve shown on the Figure 71 First of all the software eliminates data which belong to the Null and Saturations regions After that the rest data will be split onto four curves The software finds the best linear approximation for each of these curves 1 Line 1 Line 4 Maximal distance between lines Line 1 Line 2 and lines Line 3 Line 4 is the Hysteresis Maximal deviation of the flow curves from Line 1 Line 4 is the Non Linearity Line 5 is the average of the Line 1 and Line 2 Line 6 is the average of the l I have to note that these regions are defined by operator In order to get the best linear approximation I used the Least Square Method DIETZ automation GmbH 41 M V Shashkov Line 3 and Line 4 These two lines Line 5 and Line 6
6. Fo Frequency Hz Figure 73 Amplitude ratio characteristics of a Parker Hannifin servovalve Step Response Analysis A very important dynamical characteristic of a servovalve is a response for a step type control signal see Figure 74 The main parameters of such a test are Rise Time and Overshoot These parameters for positive and negative steps are demonstrated on Figure 74 10 Positive overshoot Positive rise time 100 Negative rise time Feedback V 0 0 01 0 015 0 02 0 025 0 03 0 035 0 04 0 045 0 05 Negative overshoot 4 5 Figure 74 Step response of a direct drive Parker Hannifin servovalve DIETZ automation GmbH 44 M V Shashkov Excel File with Results General Information Excel Sheet Test information Test name Name of the test Comment Any comments for the test Customer Customer name Operator Operator name Date Test date Time Test time Control configuration and conditions Control type Type of the control signal Coil connection Configuration of the valve coils Polarity of control Polarity connection of the control Spool position Type of spool position signal temperature Temperature of oil at the test Tests which were done Pressure test Pressure Leakage test was made or not Flow test A lt gt B Flow AB te
7. V Shashkov Servovalve type MOOG D633 356A LEAKAGE TEST GENERAL INFORMATION Customer Servocontrols India Valve model MOOG D633 356A Serial nummer D224 Date Thursday November 30 2006 Time 16 58 Operator DSS TEST CONDITIONS Supply pressure 140 bar Control amplitude 2 0 V Offset 0 0 V Control connection Single Polarity of control Positive TEST RESULIS Maximal leakage 1 84 L min Operator 055 DIETZ automation GmbH L min Serial number D224 Control signal Date Thursday November 30 2006 Figure 64 Leakage diagram Parker Hannifin GmbH 8 KG Time 4 58 PM V Shashkov Servovalve type MOOG D633 356A Serial number D224 SPOOL POSITION TEST Parker Hannifin GmbH amp Co KG GENERAL INFORMATION Customer Servocontrols India Valve model MOOG D633 356A Serial nummer D224 Date Thursday November 30 2006 Time 16 58 Operator DSS a TEST CONDITIONS Supply pressure 70 bar Control amplitude 5 0 V Offset 0 0 V m Control connection Single Polarity of control Positive Spool signal 4 20mA a a TEST RESULTS Gain 0 79 mA V Shift 11 81 mA Hysteresis 0 06 Spool position Control signal Operator DSS Date Thursday November 30 2006 Time 4 58 PM Figure 65 Plot of the spool position DIETZ automation GmbH 35 V Shashkov Servovalve type MOOG D633 356A Serial number D224 FLOW TEST Parker H
8. 0 to the overlay region e Natural Frequency Frequency where the phase lag equals to 90 Analysis of the Amplitude Ratio Curve e Amplitude Ratio Test The curve belongs 1 or does not belong 0 to the overlay region Natural Amplitude Amplitude ratio at natural frequency Amplitude Max Maximal amplitude ratio Amplitude Max Frequency Frequency where the amplitude equals to the maximum 3 dB Frequency Frequency where the amplitude ration equals to 3 dB Measured Data Frequency Values of the test frequencies e Phase Values of the phase lag e Amplitude Values of the amplitude ratio Phase Overlay Frequency x values of the overlay curves min y values for low limit overlay curve e Phase max y values for high limit overlay curve Flow B Overlay Frequency x values of the overlay curves Amplitude min y values for low limit overlay curve Amplitude max y values for high limit overlay curve DIETZ automation GmbH 5 M V Shashkov Step Response Test Excel Sheet Step Test conditions Supply Pressure System pressure Offset Offset of the control signal Amplitude Amplitude of the control signal Analysis of the Step response Curve Step Response Test The curve belongs 1 or does not belong 0 to the overlay region Rise Time Rise time for pos
9. EXCEL SHEET PRESSURE see eere e eene annu annua nnn 45 FLOW AB TEST EXCEL SHEET FLOW ABY 21 6 6001 308 1 er nana sna anna aaa n ananas 48 FLOW A TEST EXCEL SHEET eren esee ene n enean nana nnn a arenas 49 FLOW B TEST EXCEL SHEET FLOW B ct cis exsessseu Gu ba oput a SEED FERE eR EDS 50 DIETZ automation GmbH s M V Shashkov DYNAMIC TEST EXCEL SHEET DYNAMICS 21 er eene an nana anna aaa u aaa aaa a uana 51 STEP RESPONSE TEST EXCEL SHEET STEP rece rere eene nena aan n aaa u aaa nnus 52 SAFE FLOW TEST EXCEL SHEET 22 10 07 4404 nana naa rnras 52 SAE RECOMMENDED TERMINOLOGY 53 SERVOVALVE DIRECT DRIVE FLOW CONTROL eee nean annu n ana a anu hh aaa uaa uaa 53 ELECTRICAL CHARACTERISTICS Eo eed pi s 54 STATIC PERFORMANCE CHARACTERISTICS esser nean nu nna a anna uana aa ana aan aaa R nnus 55 DYNAMIC PERFORMANCE CHARACTERISTICS DIETZ automation GmbH 3 M V Shashkov Introduction ValveExpert 15 an automatic test stand for checking maintenance and adjustment of servo and proportional valves This test equipment is developed in accordance to t
10. and measured with control ports blocked Null Bias The input command required to bring the valve to null excluding the effects of valve hysteresis expressed as percent of rated current or voltage Null Shift A change in null bias expressed in percent of rated command For open loop DDVs null shift may occur with changes in supply pressure temperature and other operating conditions Null shift is predominately dependent on feedback transducer characteristics for closed loop valves DIETZ automation GmbH 60 M V Shashkov Lap In a spool valve the relative axial position relationship between the fixed and movable flow metering edges with the spool at null For a DDV lap is measured as the separation in the minimum flow region of the straight line extensions of nearly straight positions of the normal flow curve drawn separately for each polarity expressed as percent of rated command Zero Lap The lap condition where there is no separation of the straight line extensions of the normal flow curve See Figure 80 Also known as critical lap NORMAL FLOW CURVE CONTROL FLOW INPUT CURRENT INPUT CURRENT CONTROL FLOW Figure 80 Overlap The lap condition which results in a decreased slope of the normal flow curve in the null region See Figure 81 NORMAL FLOW CURVE INPUT CURRENT CONTROL FLOW INPUT CURRENT OVERLAP REGION CONTROL FLOW Figure 81 U
11. 58 PM M V Shashkov Structure of the Report File As I mentioned above report generator puts data to a Microsoft Excel file which is based on a user defined template It saves data to eight different MS Excel sheets Pressure Flow A Flow B Dynamics Step Safe and Each data sheet contains measured data table tables for overlay curves and mathematical analysis data A general information like Valve Name Customer Name temperature Test Time and so on 15 located on the sheet Analysis of the data is base on the Linea Analysis Fourier Analysis and Step Response Analysis see pages 41 42 44 of this manual This analysis includes Maximal Flow Maximal Leakage Natural Frequency Pass Fail Evaluation Best Linear Approximation Curves and many other parameters Note that the Linear Analysis implicitly includes also the most of static parameters like Bias Pressure Gain Hysteresis Non symmetry Non linearity Overlap and so on The complete information about measured data analysis and general information you will find on the pages 45 53 of this manual Note also that user defined sheets of the template allow to prepare printout in any form and in any language For more detail please see an example data file Calibration Test system ValveExpert has robust and precision transducers which are factory precalibrat
12. Name Test name Comments Comment Parker Hannifin Corporation Customer Plot of results Shashkov Operator General test settings Hydraulic schema Hydraulic configuration of the current test LAPAAN AON OT ioo Ce Keno Woo pP HP 0 0 1 0 40 5 0 test 4 lt gt Test frequency Degaussimg Valve Opa qr a qp rrr qp rrr rg 6 0 7 0 8 0 9 0 10 0 Control 2 lt 0 Figure 61 Automatic test Control signal 3 M V Shashkov Preliminary Analysis The system makes preliminary Pass Fail evaluation of the tests right away when the automatic test 1s finished see Figure 62 After that operator can continue adjustment of the valve or save the results 10 0 Date Time Wednesday February 27 2008 12 22 1000008 Parker 3 z Warming up 70 Bias adjustment Made tests E Safe test 3 Pressure Leakage test 6 0 Not required Flow test A E tests Flow test A R 5 0 Flow test B gt R Dynamic test Phase lag Amplitude ratio 4 85 t LL Step response test 30 Test Name Test Comments Comment 2 0 Parker Hannifin Corporation Customer 1 0 shashkov Operator Passed test 2271 Differential pressure test Made tests Iceneral tast settings 8 Control pressure Pressure test Step Response V e
13. and initial phase 0 expressed by the formulas R 9 ia At 22 K io xe dt 2m At The graph of the function 0 0 represents the normalized amplitude ratio of the valve The graphical representation of the function is the phase lag Examples of phase lag amplitude ratio are shown below on Figure 72 and Figure 73 I must note that valve frequency response may vary with the input amplitude temperature supply pressure and other operating conditions Note also that for linear systems 10 K io K i 0 k 2 3 0 Deses 100 20 30 40 50 50 Phase lag Degree 70 80 90 pem m m Um Gm GN Ne GH GU GEB GER GN GA S SSSA UC GC GR Re HR CO e RO UR EES SESE EE m Ap 9 ES A A Acc EC A cc c r A c c ee ee eee c c mw cR 1 100 Frequency Hz Figure 72 Phase lag characteristics of a Parker Hannifin servovalve 8 R 0 isa formal notation for R where is small enough Usually is 5 10Hz DIETZ automation GmbH 43 M V Shashkov mm um um um un Gm Gm m RE E E 3 See ee Amplitude dB
14. contains also overlay polylines for automated pass fail evaluation The operator can use keyboard touch screen monitor touch pad panel or even bar cod scanner for fast access to the database e The system supports manual and automatic modes e The measurement data includes the most of static and dynamical characteristics Up to 15 different graphs can be obtained during one automatic test e Complete test requires about 5 minutes Computer shows the results during the testing process powerful mathematical analysis of the results is already embedded into the system The ValveExpert program saves the data in a standard MS Excel file and Excel tools can be used for an additional analysis The operator can use template files to prepare the printout forms ValveExpert can work with any measurement units i e the operator can decide which units he will use for pressure flow temperature and so on e High precision measurement tools are used All instruments are individually calibrated and scaled Nonlinear calibration allows to compensate nonlinearity of transducers and to obtain unbelievable precision The general ideas which are used in the stand can be found in http arxiv org abs math 0202070 This hydraulic station requires three phase 380 500V 80A electric power supply connection Power can increased up to 38kW 2 Water connection for cooling is required Aerospace hydraulic fluids like Skydrol Hyjet or similar req
15. position following a step command Overshoot is expressed as the percentage of over travel with respect to the commanded position and is measured with step input commands of specified amplitude DIETZ automation GmbH 63
16. shown on Figure 17 Description of these parameters are shown on Figure 20 Let me note that a current step may be programmed for each solenoid Min separately and the current may be limited for each solenoid Max see Figure 18 separately as well The nominal current can be adjusted by one parameter separately for each solenoid Note also the PWDOOA 400 electronic includes four internal programmable ramps Acceleration and deceleration are adjustable for each solenoid see Figure 19 Please look the manual form Parker Hannifin Corporation for more details Figure 13 Digital electronic module PWD 00A 400 Figure 14 A two solenoids proportional valve from Parker DIETZ automation GmbH 16 M V Shashkov Status output Enable input Command signal Solenoid 0 10V controller uc Solenoid Th Digital OV Serial inp ut 3 Supply voltage 18 30VDC S152 85 54 Switching inputs mom am um UR RO Figure 15 Circuit diagram of the module PWD 00A 400 Internal commands Ramps Min A S5 A S7 P7 B i B Min B ext analogue command Zero adjustment Figure 16 Signal flow diagram of the PWD 00 400 DIETZ automation GmbH 7 M V Shashkov General Construction Module box for snap on assembly EN 50022 Electrical Supply voltage 8 30 Current consumption max 2 Power consumpt
17. which is required to produce rated current The parameter is specified at 68 F 20 C and 15 expressed in volts DC unless otherwise noted Rated Power The electrical power expressed in watts required to produce rated current The power is specified at 68 F 20 C unless otherwise noted Chip Shear Power The electrical power required to produce chip shear force specified at 68 F 20 C and expressed in watts unless otherwise noted Continuous Power The electrical power level which may be sustained for a specified period of time with the DDV at specified fluid and ambient temperatures without exceeding material limitations that may damage the assembly or degrade performance beyond acceptable limits Normally this 15 specified at the maximum current level Maximum Power The maximum power level which corresponds with the maximum current level for the specified conditions of fluid temperature and ambient temperature Maximum power is expressed in watts Coil Resistance The DC resistance of each motor coil expressed in ohms and measure data nominal temperature of 68 F 20 C unless otherwise noted Coil Inductance The coil self inductance as measured at the winding leads with the motor at null The inductance is expressed in millihenries and measured at 1 0 kHz Since a moving motor will generate a back that will effectively increase inductance the user should specify whether a specified inductance assumes a locked m
18. 4493 Servovalve Direct Drive Flow Control An electrically commanded single stage flow control valve which produces continuously increasing flow in approximate proportion with the input voltage and drive current The term Direct Drive implies that electrical energy is converted to metering spool motion by mechanical means Force Motor The electromechanical device which 15 used to directly drive the hydraulic flow control element Number of Coils The number of independent and isolated motor windings which may be used to drive the valve The effect of all coils is nominally identical Output Stage The final stage of hydraulic distribution used in a DDV Port Fluid connection to the DDV e g supply port return port control port Two Way Valve An orifice flow control component with a supply port and one control port arranged so that action 15 in one direction only from supply port to control port Three Way Valve A multiorifice flow control component with a supply port return port and one control port arranged so that valve action in one direction opens supply port to control port and reversed valve action opens the control port to return port Four Way Valve A multiorifice flow control component with a supply port return port and two control ports arranged so that valve action in one direction opens supply port to control port 1 and opens control port 2 to return port Reversed valve action opens supply port to cont
19. 86 7 e Digital I O o Number of channels 48 o Logical level TTL Counter Timers o Number of Counter Timers 2 o Resolution 32bit o Maximal source frequency 80MHz o Minimum input pulse width 12ns Amplifier for Proportional Directional Control Valves Test stand ValveExpert equipped by digital electronic module PWD 400 form Parker Hannifin Corporation see Figure 13 It is a very flexible PWM current amplifier which drive most of two or one coils proportional directional control valves without position feedback and with maximal current up to 3 5A see Figure 14 parameters of the electronics can be adjusted via a serial connection RS232 null modem Parker Hannifin Corporation has special software ProPxD to adjust PWD 00A 400 but all settings can be simply adjusted by the program ValveExpert directly The software ValveExpert automatically programs the electronics PWD 00A 400 when operator loads settings for a valve The settings for this amplifier are shown 19 Please look http sine ni com nips cds view p lang en nid 201814 for the detailed specifications DIETZ automation GmbH 5 M V Shashkov on the Figure 53 If the valve has a bar code the programming de facto is the only one scanner click Below you will find some information about the electronics PWDOOA 400 Figure 15 and Figure 16 show circuit diagram and signal flow diagram correspondently Table with technical data are
20. Flow gain may vary with the polarity of the input with the magnitude of load differential pressure and with changes in operating conditions See Figure 78 AP STRAIGHT LINE A GENERATED TO MINIMIZE CONTROL FLOW NONLINEARITY WITH SLOPE S RATED CURRENT INPUT CURRENT B INPUT CURRENT i RATED CURRENT STRAIGHT LINE B GENERATED 2 EXAGGERATED NORMAL NONLINEARLITY A FLOW CURVE WITH SLOPE 8 y 5 sj d 5 8 SYMMETRY 5 100 5 AS S gt S 1 Figure 78 Rated Gain The ratio of rated flow to rated current or command expressed in l min A gal min V etc Flow Saturation Region The region where flow gain decreases with increasing command See Figure 77 Flow Limit The condition where in control flow no longer increases with increasing input current Flow limitation may be deliberately introduced within the DD V Symmetry The degree of equality between the normal flow gain of each polarity expressed as percent of the greater See Figure 78 Linearity The degree to which the normal flow curve conforms to the normal flow gain line with other operational variables held constant Linearity 15 measured as the maximum deviation of the normal flow curve from the normal flow gain line expressed as percent of rated command See Figure 78 DIETZ automation GmbH 58 M V Shashkov Hysteresis The differe
21. OOG D633 356A Serial number D224 GAIN FREQUENCY RESPONCE Parker Hannifin GmbH amp Co KG GENERAL INFORMATION 2 Customer Servocontrols India Valve model MOOG D633 356A Serial nummer D224 Date Thursday November 30 2006 Time 16 58 H Operator 055 0 TEST CONDITIONS Supply pressure 70 bar T Control amplitude 4 0 V an Offset 0 0 V Control connection Single Polarity of control Positive Test signal Spool position Start frequency 5 Hz End frequency 100 Hz Number of points 30 Scale Logarithmic Gain dB TEST RESULTS Natural frequency 75 9 Hz Natural amplitude 7 1 dB Maximal amplitude 0 1 dB 10 Operator DSS Date Thursday November 30 2006 Time 4 58 PM Figure 68 Plot of the Gain Frequency Response DIETZ automation GmbH 38 V Shashkov Servovalve type MOOG D633 356A STEP RESPONCE GENERAL INFORMATION Customer Servocontrols India Valve model MOOG D633 356A Serial nummer D224 Date Thursday November 30 2006 Time 16 58 Operator DSS TEST CONDITIONS Supply pressure 70 bar Control amplitude 4 0 V Offset 0 0 V Control connection Single Spool signal 4 20mA Test duration 40 msec TEST RESULTS Operator DSS DIETZ automation GmbH Spool position Serial number D224 msec Date Thursday November 30 2006 Figure 69 Plot of the Step Response 39 Parker Hannifin GmbH 8 Co KG Time 4
22. ValveExpert Check Adjust Repair oervo and Proportional Valves te gt a Automatic Test Stand M V Shashkov Contents HON c 4 REVIEW OF SPECIFICATIONS 5 APPEICATIONS Del 5 DA IL A DIUI LM CD 5 AMPLIFIER FOR PROPORTIONAL DIRECTIONAL CONTROL 5 5 SPOOL POSITION SIGNALS ena nana aano a aaa u nana aun naa aaa uaa 5 ELECTRIC POWER SUPPLY FOR SERVOVALVE RR ERR ERREUR ERE 5 HYDRAULIC FLUID 2 42 52 9 0 2 0 023 ores arid lc e PIDE DG d DI DDR 5 HYDRAULIC POWER SUPBBEY Oo Das te De Cou vue uova 5 HARDWARE 7 PLY DPA GS ee DLE 7 9 ELECTRIC POWER SUPT
23. age min y values for low limit overlay curve Leakage max y values for high limit overlay curve DIETZ automation GmbH 47 M V Shashkov Flow AB Test Excel Sheet Flow AB Test conditions Supply Pressure System pressure Offset Offset of the control signal Amplitude Amplitude of the control signal Analysis of the Flow AB Curve Flow AB Test The curve belongs 1 or does not belong 0 to the overlay region Linel FAB x0 Coordinate 0 of the first linear approximation Line 5 on Figure 71 Linel FAB x1 Coordinate x1 of the first linear approximation Line 5 on Figure 71 Linel FAB y0 Coordinate yO of the first linear approximation Line 5 on Figure 71 Linel FAB y1 Coordinate y1 of the first linear approximation Line 5 on Figure 71 FAB Hysteresis found from the first linear analysis distance between Line 1 and Line 2 on Figure 71 Nonlinearity1l FAB Nonlinearity found from first linear analysis deviation of the curve from Line 1 and Line 2 on Figure 71 Line2 FAB x0 x0 of the second linear approximation Line 6 on Figure 71 Line2 FAB 1 x1 of the second linear approximation Line 6 on Figure 71 Line2 FAB y0 y0 of the second linear approximation Line 6 on Figure 71 Line2 FAB y1 y1 of the second linear approximation Line 6 on Figure 71 Hysteresis2 FAB Hysteresis f
24. annifin GmbH amp Co KG GENERAL INFORMATION Customer Servocontrols India Valve model MOOG D633 356A Serial nummer D224 Date Thursday November 30 2006 Time 16 58 Operator DSS TEST CONDITIONS Supply pressure 70 bar Control amplitude 5 0 V Offset 0 0 V Control connection Single Polarity of control Positive TESI RESULTS Maximum 11 6 L min Minimum 13 2 L min Hysteresis 0 77 Gain 2 66 L min V Bias 0 37 V Nonlinearity 3 92 96 Nonsymmetry 3 14 Limin Control signal Operator DSS Date Thursday November 30 2006 Time 4 58 PM Figure 66 Flow diagram DIETZ automation GmbH 36 V Shashkov Servovalve type MOOG D633 356A Serial number D224 PHASE FREQUENCY RESPONCE Parker Hannifin GmbH amp Co KG GENERAL INFORMATION pond lik Customer Servocontrols India Valve model MOOG D633 356A Serial nummer D224 Date Thursday November 30 2006 Time 16 58 Operator DSS TEST CONDITIONS Supply pressure 70 bar Control amplitude 4 0 V Offset 0 0 V Control connection Single Polarity of control Positive Test signal Spool position Start frequency 5 Hz End frequency 100 Hz Number of points 30 Scale Logarithmic Degree TEST BESULTS Natural frequency 75 9 Hz Operator DSS Date Thursday November 30 2006 Time 4 58 PM Figure 67 Plot of the Phase Frequency Response DIETZ automation GmbH 37 V Shashkov Servovalve type M
25. are the linear approximations of the normalized flow curve for positive and negative control signals correspondently The difference between slopes of these curves divided onto the maximal slope is the Non Symmetry Distance between intersection points of lines Line 5 and Line 6 with x axis 15 the Overlap Line 7 is the average of Line 5 and Line 6 This line is used to calculate Flow Gain and Bias Saturation region Null region Overlap Figure 71 Illustration of the linear analysis Frequency Response Analysis One of main dynamical characteristics of a servovalve 15 the Frequency Response This 15 the relationship between no load control flow or spool position signal and harmonic sinus type input signal Frequency response expressed by the amplitude ratio and phase angle which are constructed for harmonic signals from a specific frequency range Below I give definition of the amplitude ratio and phase lag based on the Fourier method Let x t be the control flow or spool position signal corresponding to input signal u t Asin t Here 27 f frequency of the test signal After some transition time Af the output signal x t will be a periodic function with the same frequency this case x t can be represented by the following Fourier series x t Y sin kat k 0 DIETZ automation GmbH 42 M V Shashkov For any k the amplitude
26. can use the touch screen monitor or touch pad on the keyboard to access the buttons Moreover functions of these buttons are duplicated by functional keys on the keyboard Operator can use also a bar cod scanner see Figure 34 for fast access to the database when he loads or saves settings In this case he will never make a mistake and load wrong settings Load settings EIN Figure 33 Main control buttons Figure 34 Bar cod scanner DIETZ automation GmbH 223 M V Shashkov Hydraulic Configurations Virtual hydraulic laboratory has five different hydraulic configurations Figure 35 Figure 39 below show all possibilities These hydraulic configurations are used to measure flow leakage differential pressure spool position different dynamic characteristics like step response phase frequency response amplitude frequency response and so on One touch of the screen and operator changes the hydraulic schema Depending on the selected schema stand ValveExpert configurates valves K1 K7 see Figure 1 Hydraulic schema Dynamic test with cylinder Figure 35 Frequency response test with measurement cylinder Hydraulic schema Pressure Leakage test Figure 36 Test of the leakage and differential pressure DIETZ automation GmbH Hydraulic schema Flow test lt gt B Figure 37 Test of the flow between control ports A and B Hydraulic schema Flo
27. ce 15 required The program ValveExpert analyses transducers data and will immediately stop testing if there is a problem see page 24 The hardware alarm level is supported by the electronics ValveExpert It has four alarm state indicators see Figure 8 They are blinking if there is a problem Figure 9 shows the possible alarm states Stand OFF it Filter 10u Filter Power supply T transducer DIETZ automation GmbH X Te Te HM Te He Fe X Tk High temperature P transducer High pressure Oil level High flow Motor Figure 9 List of possible values for the alarm indicators on the electronics 12 M V Shashkov Computer Subsystem The computer subsystem is based on Intel Core2 Duo E6600 processor IGB RAM and 16 bit high speed digital acquisition card NI PCIe 6259 The system includes a 19 touch screen monitor a stainless steel keyboard with touch pad and a bar code scanner see Figure 10 Software includes Windows XP operation system drivers MS Excel and ValveExpert program Figure 10 Touch screen monitor keyboard with touch pad and bar code scanner DIETZ automation GmbH 13 M V Shashkov Motor Electronics Hydraulic power pack of the stand is based on a low noise gear pump and a 38kW asynchronous motor In order to regulate the system pressure a special electronics regulates rotation freque
28. daptor manifolds allow to use this test equipment for different purposes Type of amplifier depends of the servo valve Maximal current is for 15 and 5A for the power supply 24V DIETZ automation GmbH 5 M V Shashkov a water connection for cooling Note the temperature control system allows to stabilize the oil temperature in a specified range with tolerance 2 DIETZ automation GmbH 6 M V Shashkov Hardware Hydraulics Hydraulic schema of the test stand ValveExpert 15 shown on the Figure 1 The most of hydraulic components are mounted on one steel manifold see Figure 2 The only top quality components are used Directional valves K1 K7 are used to configure the hydraulic schema The main configurations are described in the section Hydraulic Configurations Test stand ValveExpert i This test equipment was made i in accordance to the specification of Parker Hannifin Corporation and satisfies the standards established in SAE ARP 490 and ARP 4904 Author M Shashkov DIETZ automation GmbH C1 30kW 5 R2 2 9 H1 30kW Pom e m5 600W Pu HEM gt UHM R4 R33 P1 M1 M2 supply Return Figure 1 Hydraulic schema of the stand ValveExpert T
29. e adjusted via ValveExpert software Spool Position Signals Feedback The most of modern servo or proportional valves have a build in electronics These valves are usually equipped by spool position transducers ValveExpert can check the signal from such a transducer The standard signal ranges 10V 10mA 20mA 4 20mA are supported Electric Power Supply for Servovalve Servovalves with build in electronics require external power supplies In the most cases it is 15V or 24V Such power suppliers are built in the test stand Hydraulic Fluid The test stand ValveExpert was developed and tested for a mineral oil with viscosity about 30 cSt We recommend you to use Mobil DTE24 Shell Tellus 29 MIL H 5606 MIL H 83282 MIL H 87257 or oil with the similar parameters Note that aerospace hydraulic fluids like Skydrol or Hyjet require modifications in the stand construction The integrated filtration system achieves a cleanliness level 5 of NAS1638 level 14 11 of 1504406 or better The capacity of the oil tank is about 100L 26Gal Hydraulic Power Supply The test stand does not require an external hydraulic power supply A modern high efficient and low noise 30kW hydraulic power station is already inside Maximal flow of the power station 15 80 L min 21 Gal min and working pressure is up to 350 bar 5000 PSI The integrated hydraulic power pack requires three phase 380 500V 80A electric power supply connection and Additional a
30. e y1 of the linear approximation Hysteresis SP3 Hysteresis Nonlinearity SP3 Nonlinearity SP3 Min Minimal value DIETZ automation GmbH 49 M V Shashkov SP3 Max Maximal value Measured Data Control Values of the control signal Feedback Values of the spool position transducer Flow A Values of the flow between ports and Feedback Overlay Control x values of the overlay curves Feedback min y values for low limit overlay curve Feedback max y values for high limit overlay curve Flow A Overlay e Control x values of the overlay curves A min y values for low limit overlay curve A max y values for high limit overlay curve Flow B Test Excel Sheet Flow B Test conditions e Supply Pressure System pressure Offset of the control signal Amplitude Amplitude of the control signal Analysis of the Flow B Curve B Test The curve belongs 1 or does not belong 0 to the overlay region Line FB x0 Coordinate 0 of the linear approximation Line FB x1 Coordinate x1 of the linear approximation Line FB y0 Coordinate yO of the linear approximation Line FB y1 Coordinate y1 of the linear approximation Hysteresis FB Hysteresis Nonlinearity FB Nonlinearity Min Minimal value
31. ed Nevertheless all transducers of the test stand can be simple recalibrated by an operator In order to calibrate a transducer the operator has to use Measurement amp Automation Explorer MAX This National Instruments software allows to use different formulas for calibration and choose physical units for pressure flow temperature and so on In order to calibrate a transducer the operator has to correct the correspondent scale The example below see Figure 70 shows a linear scale which calculates pressure from voltage This scale uses the linear formula y 2 for the calculations Here m 58 13953 b 100 x 1s voltage from the pressure transducer Ps supply pressure in bar The operator can use also nonlinear scales Nonlinear scales use polynomial formulas or tables for calculations These scales allow to compensate nonlinearity of transducers and to obtain unbelievable precision For more details about the scales please read the MAX manual Software ValveExpert uses the following scales Flow scale for flowmeter Level scale for oil level transducer Pa scale for pressure transducer Pb scale for pressure transducer Pb Pb Pa scale for differential pressure Pb Pa Piston scale for piston position transducer of frequency response cylinder Ps control scale for supply pressure control signal Pspeed scale for piston speed transducer of frequency response cylinder SP mA scale to measure current from s
32. el file In order to prepare a view form of the printout the operator can use a template file Such a template contains the only information that the customer wants to have the report 1 e text data formulas pictures conditional formatting for pass fail evaluation and so on Note that different configurations may have different templates files In this case type of the report can depend of custom name valve name and so on For instance customers from different countries can have reports in different languages I have to note also that template file can get a photo of a vale you test For more details please read MS Excel manual Figure 63 Figure 69 below show examples for the output forms DIETZ automation GmbH 5 2 V Shashkov Servovalve type MOOG D633 356A DIFFERENTIAL PRESSURE TEST GENERAL INFORMATION Customer Servocontrols India Valve model MOOG D633 356A Serial nummer D224 Date Thursday November 30 2006 Time 16 58 Operator DSS TEST CONDITIONS Supply pressure 140 bar Control amplitude 2 0 V Offset 0 0 V Control connection Single Polarity of control Positive TEST RESULTS Gain 277 bar V Bias 0 08 V Hysteresis 0 39 96 bar Operator 055 DIETZ automation GmbH Serial number D224 Parker Hannifin GmbH amp Co KG tt PE Tey EE Control signal Date Thursday November 30 2006 Figure 63 Differential pressure plot 33 Time 4 58
33. eration B solenoid 0 1 2 3 4 Nominal current A solenoid 0 0 8 123 5A 222 74 321 8A 4 lt 1 0 1 2 3 4 Nominal current B solenoid 0 0 123 5A 2 2 7 321 8A 4 1 3 Figure 20 Description of the parameters for PWD 00 400 Servovalve Installation In order to test a servo or proportional valve operator has to use a proper adapter manifold for hydraulic power supply and a proper electric cable One or two coils proportional valves without feedback electronics require connection to the power PWM amplifier see Figure 21 The mounting manifold must conform to ISO 10372 06 05 0 92 Pinout configurations of the test stand connectors are shown on Figure 24 Figure 25 and Figure 26 Please note that you will need a dynamic cylinder see Figure 27 to measure frequency response data of you valve if it has not a spool position transducer Such a frequency response cylinder is an optional equipment Coil connectors see Figure 26 are used to drive two or one coils proportional directional control valves without position feedback see Figure 14 Connector for solenoid A 1 m 3i Connector for Connector for solenoid dynamic cylinder Proportional valve servo proportional valve Adapter manifold Figure 21 Installation of a two solenoid proportional valve without electronics DIETZ automation GmbH 19 M V Shashkov Servovalve Main connector for servo p
34. ervovalve spool position transducer SP V scale to measure voltage from servovalve spool position transducer SV 10mA scale to measure control current in 10mA range SV 10mA control scale for control signal in 10mA range SV 10V scale to measure control voltage in 10V range SV 10V control scale for control signal in 10V range SV 20mA scale to measure control current in 20mA range SV 20mA control scale for control signal in 20mA range SV 50mA scale to measure control current in 50mA range SV 50mA control scale for control signal in 50mA range SV 100mA scale to measure control current in 100mA range DIETZ automation GmbH 40 M V Shashkov SV 100mA control scale for control signal in 100mA range T tank scale for oil temperature transducer XE Ps Measurement amp Automation Explorer File Edit View Tools Help Configuration 4 Show Help e System H Data Neighborhood H Devices and Interfaces QA Scales NI DAGm x Scales Flow 5 Level gt gt Scaling Parameters Linear Scale ajj Pa z il Slope T Intercept Pb 2 58 13953 Piston Ps control Resulting Equation Pspeed Y 58 13953 X 100 SP mA 5 5 1UmA Pre Scaled Scaled 5v 10m4 control Walks 5v 10V 5v 10V control SY 204 5v 20m4 control 5v 50 5v 5
35. fferential pressure List name Figure 58 Table of points which specifies the overlay polylines Overlay curves and cut off regions Bias Adjustment Software ValveExpert has a special tool which helps to adjust null point bias of a servovalve There are two ways for that First way is to adjust the valve by the differential pressure test The zero differential pressure corresponds to the hydraulic null of the valve This fact is true for zero cut valves i e which have not overlap A servo or proportional valve with an overlap must be adjusted by the flow test In this case program generates a periodical signal and the operator has to adjust the flow value to have a symmetry for positive and negative control signals Figure 54 and Figure 57 show parameters for these two ways of the bias adjustments Figure 59 and Figure 60 show examples when the Bias Adjustment test is started The indicators show if the values are in the tolerance ranges Indicator of symmetry Indicator is green if the differential pressure in the tolerance interval Differential pressure Indicator of the positive flow nominal flow Press this button to continue the test Figure 59 Bias adjustment by the differential Figure 60 Bias adjustment by the flow test pressure test DIETZ automation GmbH 30 M V Shashkov Automatic Test In order to make an automatic test the operator loads
36. he specification of the Parker Hannifin Corporation and satisfies the standards established in SAE ARP 490 and ARP 4904 Below are the main features Wide range of servo and proportional valves 15 supported Testing flow 15 up to 60 L min 21 Gal min and working pressure is up to 350 bar 5000 PSI Compact high efficient and low noise 30kW hydraulic power station is already inside Temperature control system stabilizes the oil temperature in a specified range with tolerance 2 C e The integrated filtration system achieves a cleanliness level 5 of NAS1638 level 14 11 of ISO44006 or better e An additional the last chance 10u filter protects the valve from contamination e Extremely robust construction of the stand The most of hydraulic components are mounted on one steel manifold The only top quality components are used e Multi level alarm system protects the operator from risky conditions This system informs the operator if service 15 required e Different hydraulic liquids can be used e The computer subsystem is based on the Intel Core2 Duo E6600 processor 1GB RAM and 16 bit high speed digital acquisition card NI 1 6259 The computer interface is intuitively clear and simple Special education and knowledge are not required Operator works with a powerful virtual hydraulic laboratory on a 19 inch touch screen monitor Internal user defined database keeps all test parameters This database
37. hese hydraulic components are shown in the blue area see Figure 1 DIETZ automation GmbH 7 M V Shashkov Pressure i transdsucer Figure 2 The most of hydraulic components are mounted on one steel manifold Hydraulic power pack see Figure 3 uses a low noise internal gear pump and a brushless motor with variable rotation frequency Maximal power of the hydraulic system depends of the motor electronics and can be up to 38kW Maximal working pressure is 350bar SOOOPSI Maximal flow is 80L min 21 Gal min 1 Electronics for 600W motor Heat exchanger for water cooling n z i 600 motor Water valve Figure 3 Hydraulic power pack DIETZ automation GmbH 8 M V Shashkov Water Cooling ib 1 chance Figure 4 Industrial water connection for cooling of the oil Electric Power Supply Electric schema of the stand is shown below see Figure 5 Figure 6 and Figure 7 show electric power distribution on the stand MLV Shashkov DIETZ automation GmbH Figure 5 Electric schema of the stand DIETZ automation GmbH 9 M V Shashkov Figure 6 ValveExpert requires three phase 380 500V 80A electric power supply Power motor Main fuse for the fuse for B electronics small power motor motor heater a m WI Figure 7 Electric distribution DIETZ automation GmbH 10 M V Shas
38. hkov Interface Electronics Power supply 15V 30 24V Servovale Reserved Reserved zu Oil temperatuire On Off Servovalve Alarm Indicator Pb transducer Frequency response cylinder 1 n uu HS Iz T 1 4 NM ma AT TTC a r Hn T lH Ee L4 p E E 1 i E t p i i 1 m 1 a E 1 ud tg a E 1 1 ILES owl a Ps transducer E Heserved E wm E i Ez T l e 4 as E EI n NI connector 0 I EEEE ow E 4 c a EE zi F 3 D a Power motor control E Frequency for small motor On Off power motor L 4 1 4T WO NW X X M V Shashkov DIETZ automation GmbH Figure 8 Interface electronics of the test stand ValveExpert DIETZ automation GmbH 11 V Shashkov Alarm Indicators of the Electronics Multi level alarm system protects the operator from risky conditions This system informs the operator if servi
39. ine PA x1 Coordinate x1 of the linear approximation Line PA y0 Coordinate yO of the linear approximation Line PA y1 Coordinate y1 of the linear approximation Hysteresis PA Hysteresis Nonlinearity PA Nonlinearity Min Minimal value Max Maximal value Analysis of the Pressure B Curve Pressure B test Pressure B curve belongs 1 or does not belong 0 to the overlay region Line PB x0 Coordinate 0 of the linear approximation for the pressure B curve Line PB x1 Coordinate x1 of the linear approximation for the pressure B curve Line PB y0 Coordinate yO of the linear approximation for the pressure B curve Line PB yl Coordinate y1 of the linear approximation for the pressure B curve Hysteresis PB Hysteresis of the pressure B curve Nonlinearity PB Nonlinearity of the pressure B curve Min Minimal value Max Maximal value Analysis of the Leakage Curve Leakage Test The curve belongs 1 or does not belong 0 to the overlay region Leakage Min Minimal value DIETZ automation GmbH 46 M V Shashkov Leakage Max Maximal value Analysis of the Spool position Curve Spool Position 1 Test The curve belongs 1 or does not belong 0 to the overlay region Line SP1 x0 Coordinate 0 of the linear approximation Line SP1 x1 Coordinate x1 of the l
40. inear approximation Line SP1 y0 Coordinate yO of the linear approximation Line SP1 y1 Coordinate y1 of the linear approximation Hysteresis SP1 Hysteresis Nonlinearity SP1 Nonlinearity SP1 Min Minimal value Max Maximal value Measured Data e Control Values of the control signal Pressure AB Values of the differential pressure Pressure A Values of the pressure A Pressure B Values of the pressure B Feedback Values of the spool position transducer Leakage Values of the leakage Differential Pressure Overlay e Control x values of the overlay curves Pressure min y values for low limit overlay curve Pressure AB max y values for high limit overlay curve Pressure A Overlay e Control x values of the overlay curves e Pressure min y values for low limit overlay curve Pressure max y values for high limit overlay curve Pressure B Overlay e Control x values of the overlay curves Pressure min y values for low limit overlay curve e Pressure max y values for high limit overlay curve Feedback Overlay e Control x values of the overlay curves Feedback min y values for low limit overlay curve Feedback max y values for high limit overlay curve Leakage Overlay e Control x values of the overlay curves Leak
41. ion max at 24V 36 Fuse 2 5 medium lag 0 10 150kOhm 0 5 8 5 30 Outputs Digital 0 0 5 1 Supply voltage 15mA load solenoids 0 8 1 3 1 8 2 7 3 5 Interfaces Serial RS 232C null modem Adjustment ranges MIN 1000 0 50 current MAX 1000 50 100 current Ramps 32 5 Dither Amplitude 100 0 16 current Frequency 7 0 800 Zero position 1000 1000 75 75 current Protection Industrial protection class IP20 Environment Temperature 40 70 Connection Wire connection Screwable AWG 24 13 plug in conform to standards EN 50081 2 EN 50082 2 Figure 17 Technical data of the module PWD 00 400 current P3 Max A P7 Min A Min command P4 Max B Figure 18 Min Max function and nominal current adjustment stroke Figure 19 Ramp function DIETZ automation GmbH 18 M V Shashkov 1 0 0 1000 Zero point adjustment Reserved 0 1000 current A solenoid 0 1000 Max current B solenoid 0 100 Dither amplitude 100 16 max current 0 800 0 Dither frequency 0 1000 Min current A solenoid 0 1000 Min current B solenoid 1000 1000 Internal command 1 1000 1000 Internal command 2 1000 1000 Internal command 3 1000 1000 Internal command 4 0 32500 Acceleration A solenoid 0 32500 Deceleration A solenoid 0 32500 Acceleration B solenoid 0 32500 Decel
42. itive step control signal Overshoot Overshoot for positive step control signal Star Signal Start signal for positive step control signal End Signal End signal for positive step control signal Rise Time Rise time for negative step control signal Overshoot Overshoot for negative step control signal Star Signal Start signal for negative step control signal End Signal End signal for negative step control signal Measured Data Time Values of the time Input Input signal Output Output signal Output Overlay Time x values of the overlay curves Output min y values for low limit overlay curve Output max y values for high limit overlay curve Safe Flow Test Excel Sheet Safe Test conditions Supply Pressure System pressure Specifications Nominal Safe Flow The specified flow for switched off servo or proportional valve Flow Tolerance Tolerance for the nominal flow Analysis of the Safe Flow Test e Safe Test Safe Flow belongs 1 or does not belong 0 to the tolerance region Safe Flow Measured flow for switched off servo or proportional valve DIETZ automation GmbH 2922 M V Shashkov SAE Recommended Terminology The following definitions describe recommended terminology for Direct Drive Servovalves made by Society of Automotive Engineers SAE in ARP
43. just by one touch of the screen All measuring and control devices can be simply adjusted These adjustments can be saved in a database which contains also all parameters for the automatic tests and some additional information Functions of the main buttons are duplicated by the functional keys F2 F12 see Figure 30 The key FI calls an information screen of the program Detailed description of the virtual hydraulic laboratory is done below FRETTEN 1 34PM CENE UE Vg ENS E E 140 12 1 4 5 Comments arker Hannifin Corporation gt E S 5 S x amp S General test settings 2 DO 2 6 8 ant 410 AA Figure 28 Manual mode of virtual hydraulic laboratory ValveExpert DIETZ automation GmbH 22 M V Shashkov Date Time Monday February 25 2008 1 59 PM 1000004 Parker 3 Warming up Bias adjustment Safe test Pressure Leakage test Flow test lt gt B Flow test gt R Flow test B gt R Dynamic test Phase lag Amplitude ratio Step response test Test Name Test name Comments Comment Parker Hannifin Corporation Customer Shashkov Operator General test settings Phase lag Degree Hydraulic schema 1 I 10 0 100 0 400 0 Frequency Plot Phase lag a um P i A 400 H Degaussing 4100 mA 2 M UE 120 50 Alar
44. ll equal the supply pressure minus the return pressure minus the load pressure drop Pressure Gain The rate of change of load pressure drop with input command at zero control flow control ports blocked expressed bar amp psi volt etc Pressure gain is usually specified as average slope of the curve of load pressure drop versus command between 40 of maximum load pressure drop See Figure 79 DIETZ automation GmbH 59 M V Shashkov 100 LOAD PRESSURE DROP WITH CONTROL PORTS BLOCKED LOAD PRESSURE DROP 40 SLOPE 15 PRESSURE GAIN INPUT CURRENT 40 INPUT CURRENT 100 Figure 79 Null Region The region about null where in effects of lap 1 initial metering geometry in the output stage are dominant Element Null Each hydraulic channel has its own individual null It 15 the valve position where with a specified set of supply and return pressures that hydraulic channel supplies zero control flow at zero load pressure drop Valve Hydraulic Null This 1s the valve position where if each valve hydraulic channel were connected to its own equal area cylinder in a tandem actuator with a specified set of supply and return pressures the actuator would not move Except for a simplex valve this valve position will generally not coincide with the null positions of the individual elements Null Pressure The pressure existing at both control ports at null expressed in psi or bar
45. lluted EA Problem with power supply e Temperature transducer does not work properly e Oil temperature exceeded the maximum value tte x z Pe 7 Supply pressure transducer does not work properly 3 System pressure exceeds the maximum value me Oil level 15 too low hal Alarm signal from the motor electronics E Flow through the flow meter exceeded the maximum value DIETZ automation GmbH 2242 M V Shashkov Universal Amplifier Controls of the universal amplifier are shown on Figure 32 Power supply for servovalve Control Degaussing Valve ON On Off feedback Polarity of control Figure 32 Controls of the universal amplifier Control knob This amplifier has 4 modes manual control generator degaussing and feedback mode In order to control valve manually operator can use the control knob The generator mode is used for the automatic control This mode supports the following standard signals sawtooth l triangle NI sinus square Frequency of generator belongs to interval 0 001 1000 Hz Degaussing signal allows to eliminate the initial magnetic field of the valve In the feedback mode the system finds the bias of the control The Main Controls The main control buttons are shown on Figure 33 They are used to load or save settings start or stop automatic testing process exit the program and so on The operator
46. losing a position loop within the DDV Closed loop systems typically enjoy improved performance characteristics and reduced sensitivity to construction variations at the cost of added complexity Devices for electrical position feedback include LVDTs RVDTs radiomatic potentiometer and Hall effect sensors Mechanical feedback can be accomplished by the use of springs linkages or gears Electrical Characteristics Input Current The DC or effective pulse modulated current supplied to the motor coils expressed in amperes per channel or amperes total Rated Current The input current of either polarity supplied to the motor coils which 15 required to produce rated no load flow under specified conditions of fluid temperature number of operating channels and differential pressure expressed in amperes per coil or amperes total Maximum Current The maximum input current expressed in amperes per coil or amperes total that may be applied to the DDV motor coils as limited by the control amplifier Chip Shear Current The input current expressed as amperes per coil or amperes total required to produce the specified chip shear force at the valve metering element Typically the chip shear current and the maximum current are the same Supply Voltage The maximum voltage which may be used meeting the specified performance requirements Rated Voltage DIETZ automation GmbH 54 M V Shashkov The input voltage of either polarity
47. m system o tt 1 M 75 T 80 80 Signal rI Coil 1 29 T 4 20 mA 50 N 2200 602 Vida 20 3 257 27225 Power Motor 40 40 Generator 13 y 204 Feedback Polarity Parallel 0 i 20 70 E 10 m n3 e Figure 29 Automatic mode of laboratory ValveExpert Phase Frequency test 70 bar ee Heater Cooler L H EURO Degaussing Valve ON Coil 2 9 i00 125 150 0 100 WU EE t UN 120 isa E Alarm system J 80 80 S022 N 2200 60 60 257 2225 Power Motor 40 402 OK Generator 8 8 Feedback Polarity Parallel 7 X gt 0 250 20 Figure 30 Functional keys of the controls DIETZ automation GmbH 23 M V Shashkov Hydraulic Power Supply Controls and indicators of the hydraulic power pack are shown on Figure 31 High limit of oil temperature Alarm indicator Low limit of oil temperature Oil temperature Moto EN Cooler 35 Alarm system oc y 80 100 179 150 g 2200 3 OK 2 ga Motor Enable Disable switch Figure 31 Controls of the hydraulic power station 100 80 40 a Power On Off switch Possible values of the alarm indicator are 2 System is ready to work A e ValveExpert is switched off Emergency switch 15 activated Na filter is polluted 10u filter is po
48. nce in the valve input command required to produce the same valve output during Single cycle of valve stroke when cycled at a rate below that at which dynamic effects are important Hysteresis is normally specified as the maximum difference occurring in the flow curve throughout plus or minus rated command and is expressed as percent of rated command See Figure 75 Threshold The increment of input command required to produce a change in valve output expressed as percent of rated command increment required to revert from a condition of increasing output to a condition of decreasing output when valve command is changed at a rate below that at which dynamic effects are important Internal Leakage The total internal valve flow from pressure to return with zero control flow usually measured with control ports blocked expressed in l min or gal min Leakage flow will vary with valve position generally being a maximum at the valve null null leakage Load Pressure Drop The differential pressure between the control ports expressed in bar or psi In conventional DDVs load pressure drop may be expressed as an equation where in it is equated to the supply pressure less return pressure and less the pressure drop across the active control orifices lt 1 The sum of the differential pressures across the control orifices of the output stage expressed in psi or bar Valve pressure drop wi
49. ncy of the motor The electronics contains also a digital signal processor DSP with PI closed loop system Such a controller allows to stabilize the supply pressure with high accuracy Cooling Filtration system has a very similar construction Such an approach combines high efficiency with extremely low noise EI Power supply distribution Power motor electronics eee SF with DSP system edicion Computer oe 5 TL A LI 1 1 Power supply 2x 15V Interface electronics Small motor electronics Oil level transducer Temperature ran r loi i transduce Oil 3p filer With sensor Oil tank with gear pumps inside Water valve Figure 11 Hydraulic power pack and electronics DIETZ automation GmbH 14 M V Shashkov Data Acquisition Electronics The heart of the measurement subsystem is the National Instruments PCIe 6259 card see Figure 12 This is a high speed multifunction M Series data acquisition board designed for PCI 10 Express bus The main features are ppm m c Hm ru i W de d pecori Figure 12 National Instruments PCle 6259 card Bustype PCI Express x1 Analog Input o Number of channels 16 o Resolution 16bit o Maximal sample rate 1 25MHz Analog output o Number of channels 4 o Resolution 1661 o Maximal sample rate 2
50. nderlap The lap condition which results in an increased slope of the normal flow curve in the null region See Figure 82 DIETZ automation GmbH 61 M V Shashkov NORMAL FLOW CURVE CONTROL FLOW INPUT CURRENT INPUT CURRENT UNDERLAP REGION CONTROL FLOW Figure 82 Intersystem Leakage Applies to tandem valves wherein fluid from one hydraulic system may be internally transferred to the other system This is measured with one system at the specified operating pressures while the system under test is vented to atmosphere The leakage is usually expressed in l min or gal min and this measurement is normally made with the valve held at null Null Coincidence On valves which incorporate a means to measure output element position the difference between the zero position of such a measurement and hydraulic null of the valve or each side of a tandem valve expressed in displacement units Pressure Mismatch The differential pressure in psi or bar between the output pressures of the elements of a tandem valve when the valve assembly is at hydraulic null Flow Mismatch The difference in flow between any two valve elements expressed as a percentage of the smaller flow with the valve at a fixed position and with the same supply and return pressures applied to each system Position Measurement Error On valves which incorporate means to measure output element position the difference between the measured
51. nt Amplifier rogram a List name Figure 53 Parameters for PWM current amplifier Figure 56 Parameters for Warming up process Type of the bias adjustment Supply pressure Amplitude of the control Flow at maximal control Maximal flow difference for maximal and minimal control signals Type of the bias adjustment Offset of the control 70 negative controls i ES Maximal pressure deviation Flow tolerance List name Bias ad Figure 57 Parameters for bias adjustment by Figure 54 Parameters for bias adjustment by flow differential pressure DIETZ automation GmbH 29 M V Shashkov y value of the low limit Overlay curves y1 bar y2 bar 350 350 350 350 List of the supported overlays V Differential pressure Control pressure Control pressure B Leakage Spool position Pressure test Flow test lt gt Control pressure Flow test lt gt Spool position Flow test lt gt Flow test gt R Spool position Flow test gt Flow test gt R Spool position Flow test B gt Phase lag Amplitude ratio Step response Saturation region 9 5 N ame of th e Null region 9 5 t bl Plot name over ay able Di
52. otor or one that is free to rotate Transformer Coupling The mutual inductance between individual coils of the motor driven by separate control amplifier channels The measurement may be expressed V V with the test coil left open circuit or in A A with the test coil shorted and in a specified frequency range Polarity The relationship between the direction of control flow and the direction of input current or voltage Dither A low amplitude relatively high frequency when compared to the DDV natural frequency periodic electrical signal sometimes superimposed on the DDV input to reduce threshold Dither is expressed by the dither frequency Hz and the peak to peak dither current or voltage amplitude Static Performance Characteristics Control Flow DIETZ automation GmbH 2595 M V Shashkov The flow through the valve control ports expressed in l min or gal min Control flow 15 referred to as loaded flow when there is load pressure drop Conventional fest equipment normally measures no load flow Rated Flow The specified control flow corresponding to rated command at specified temperature and pressure conditions and specified load pressure drop Rated flow is normally specified as the no load flow Flow Curve The graphical representation of control flow versus input current or command This is usually a continuous plot of a complete full flow valve cycle See Figure 75 CONTROL FLOW HYSTERESIS
53. ound from the second linear analysis distance between Line 3 and Line 4 on Figure 71 Nonlinearity2 FAB Nonlinearity found from the second linear analysis deviation of the curve from Line 3 and Line 4 on Figure 71 FAB Min Minimal value FAB Max Maximal value Analysis of the Load Pressure Curve at Flow AB test Flow Pressure Test The curve belongs 1 or does not belong 0 to the overlay region Min Minimal value Max Maximal value Analysis of the Spool position Curve Spool Position 2 Test The curve belongs 1 or does not belong 0 to the overlay region Line SP2 x0 Coordinate 0 of the linear approximation Line SP2 x1 Coordinate x1 of the linear approximation Line SP2 y0 Coordinate yO of the linear approximation Line SP2 y1 Coordinate y1 of the linear approximation Hysteresis SP2 Hysteresis Nonlinearity SP2 Nonlinearity SP2 Min Minimal value S P2 Max Maximal value Measured Data DIETZ automation GmbH 48 M V Shashkov Control Values of the control signal Pressure A Values of the pressure in port A Feedback Values of the spool position transducer AB Values of the flow between ports and Pressure A Overlay e Control x values of the overlay curves Pressure min y values for low limit overlay curve Pressure max y
54. position and the actual position expressed as a percentage of the rated stroke of the output element Dynamic Performance Characteristics Frequency Response The complex ratio of flow control flow to input command as the command is varied sinusoidally over a range of frequencies Frequency response is normally measured with constant input command amplitude and zero load pressure drop expressed as amplitude ratio and phase angle Valve frequency response may vary with the input command amplitude temperature and other DIETZ automation GmbH 62 M V Shashkov operating conditions DDVs may also measure frequency response by using output spool position if a transducer is employed Normalized Amplitude Ratio The ratio of the control flow amplitude to the input command amplitude at a particular frequency divided by the same ratio at the same input command amplitude at a specified low frequency usually 5 or 10 Hz Amplitude ratio may be expressed decibels Phase Lag The instantaneous time separation between the input command and the corresponding control flow variation measured at a specified frequency and expressed in degrees Rise Time The time required to achieve 90 of commanded spool position or flow following the initiation of a specified step command amplitude under no load conditions Overshoot The valve is said to have overshoot when the valve control spool momentarily travels beyond the commanded steady State
55. rdinate 0 of the first linear approximation Line 5 on Figure 71 Linel DP x1 Coordinate x1 of the first linear approximation Line 5 on Figure 71 Linel DP y0 Coordinate yO of the first linear approximation Line 5 on Figure 71 Linel DP y1 Coordinate y1 of the first linear approximation Line 5 on Figure 71 Hysteresis1 DP Hysteresis found from the first linear analysis distance between Line 1 and Line 2 on Figure 71 Nonlinearityl DP Nonlinearity found from the first linear analysis deviation of the curve from Line and Line 2 on Figure 71 Line2 DP x0 Coordinate 0 of the second linear approximation Line 6 on Figure 71 Line2 DP x1 Coordinate x1 of the second linear approximation Line 6 on Figure 71 Line2 DP y0 Coordinate yO of the second linear approximation Line 6 on Figure 71 Line2 DP y1 Coordinate y1 of the second linear approximation Line 6 on Figure 71 152 DP Hysteresis found from the second linear analysis distance between Line 3 and Line 4 on Figure 71 Nonlinearity2 DP Nonlinearity found from the second linear analysis deviation of the curve from Line 3 and Line 4 on Figure 71 DP Min Minimal value DP Max Maximal value Analysis of the Pressure A Curve Pressure A test The curve belongs 1 or does not belong 0 to the overlay region Line PA x0 Coordinate 0 of the linear approximation L
56. rol port 2 and opens control port 1 to return port Simplex DDV A DDV which controls hydraulic flow from a single supply of fluid Tandem DDV A DDV which controls the flow of two independent hydraulic systems simultaneously Chip Shear Force The valve force available at the metering element to shear a lodged chip or foreign particle This is typically defined at the maximum valve stroke the closing direction and includes forces produced by the motor and by mechanical springs but does not include flow forces DIETZ automation GmbH 52 M V Shashkov Natural Frequency A frequency at which in the absence of damping a limited input tends to produce an unlimited output It is a function of the valve mass elements and spring rates which includes flow forces where applicable Open Loop DDV A DDV which has no electrical position feedback means for correcting error between the commanded position and the actual position These devices usually feature centering or biasing springs on the hydraulic output stage and or force motor Electrical Feedback DDV A DDV which uses electrical position feedback and an electronic amplifier to minimize the error between the commanded position and the actual control element position Rip Stop Construction A mechanical means of construction which isolates a structural failure of one hydraulic system from propagating into another Position Feedback Electrical or mechanical means for c
57. roportional valve xm manifol dapter manifold anes enl MENSEM Figure 22 Standard installation of a servo or proportional valve Main connector servo Connector for the Connector for power Connector Connector and proportional valves dynamic cylinder PWM amplifier for Coil A for Coil B Figure 23 Connectors of the stand 45V A Control Spool position OV Spool position Figure 24 Pinout configurations of the main servovalve connector and the connector for PWM amplifier cable view DIETZ automation GmbH 20 M V Shashkov Position Speed Position Figure 25 Pinout configurations of the connector for frequency response cylinder cable view Coil Coil GND NGND Figure 26 Pinout configurations of the coil connector of the PWM current amplifier cable view NC Figure 27 Frequency response cylinder DIETZ automation GmbH 2 lt M V Shashkov Software Virtual Laboratory ValveExpert The test equipment ValveExpert has an intuitively clear software Operator works with a powerful virtual hydraulic laboratory on a 19 inch touch screen monitor This laboratory has two modes of operation Manual see Figure 28 and Automatic see Figure 29 Hydraulic schema shown on the monitor corresponds to the real hydraulic configuration of the stand Five different hydraulic configurations can be obtained
58. settings from the database chooses tests he wants to make and pushes the Start Stop button In 5 7 minutes all test will be done and the operator will get results During the test process the operator can see all plots and interrupt the test in any time The measurement data includes the most of static and dynamical characteristics Up to 15 different graphs can be obtained during one automatic test Some of them are shown below see Figure 63 Figure 69 A print screen of the automatic test 15 shown on Figure 61 Current x value Spool Position V sree see 1 0 Control Signal Vv Plot name Spool position Flow test lt gt B Motor Heater Cooler c L H n o01 He 3 100 mA __ LA Save cfg Load cfg 100 125 150 A 120 Alarm system zm cH z50mA a 7 4 4 75 S Signal 1 l Coil 1 T 2 gt 7 4 20 mA 50 N 2200 6 20 MA 257 2225 Power Motor J Feedbsck Polarity Parallel 4 t 1 ea 210 m 1 DIETZ automation GmbH Date Monday February 25 2008 1000004 Parker 3 v warming up Finished test Bias adjustment Safe test Pressure Leakage test 7 Flow test 4 gt R 7 Flow test B gt R Dynamic test Phase lag Amplitude ratio Step response test Time 11 56 PM High limit overlay 225 gt Requested tests Test
59. snsnsenennnsennsnsnsnseses 27 SETTINGS FOR THE AUTOMATIC TEST wsucecececececccccccenccenennnenenenenensecacacacannsnsesnsnsnsnsnsnsnnnsnens 28 30 AUTOMATIC deb 31 PRELIMINARY ANALYSIS 32 eee 32 STRUCTURE OF THE REPORT aaa 40 CALIBRATION cac opu DA DI CDI es M MR C ODE 40 MATHEMATICAL 5 41 LINEAR ANALYSIS M TR LIU AT 41 FREQUENCY RESPONSE ANALYSIS 42 STEP RESPONSE 9 5 44 EXCEL FILE WITH 5 2222 45 GENERAL INFORMATION EXCEL SHEET MAIN 11scccssscccnnnccensnesenenssenensnenenssenensecnensenens 45 PRESSURE LEAKAGE TEST
60. st was made or not test gt Flow A test was made or not Flow test gt Flow B test was made or not Dynamic test Dynamic test was made or not Step response test Step response test was made or not Physical Units units Physical units of the flow transducer Level units Physical units of the level transducer Temp units Physical units of the temperature transducer units Physical units of the pressure transducer Pb units Physical units of the pressure transducer PB Pb Pa units Physical units of the differential pressure transducer Ps units Physical units of the pressure transducer PS Control units Physical units of the control signal Feedback units Physical units of the feedback signal Frequency units Physical units for frequency Hz Amplitude units Physical units for amplitude damping dB Time units Physical units for time sec Pressure Leakage Test Excel Sheet Pressure Test conditions Supply Pressure System pressure Offset Offset of the control signal DIETZ automation GmbH 45 M V Shashkov Amplitude Amplitude of the control signal Analysis of the Differential Pressure Curve Differential Pressure test The curve belongs 1 or does not belong 0 to the overlay region Linel DP x0 Coo
61. t low flow Speed at low flow Trigger level Figure 49 Parameters of the Flow test through the control port A Supply pressure 70 Amplitude Trigger level Speed at low flow Speed at low flow Figure 50 Parameters of the Flow test through the control port B Supply pressure Amplitude End frequency Type of scale nas 0 100 30 Number of points List name Dynamic test Phase lag Amplitude ratio Figure 51 Parameters of the frequency response test 28 M V Shashkov Supply pressure 70 h of the C Documents and Settings Shashkov My Documents Stand Parker ValyeExpert Program printout template Template xls Amplitude List NAME step response test List name Figure 52 Parameters for the step response test Figure 55 Name of an MS Excel template file for output data Supply pressure Offset Amplitud TE jo point adjustment Parameter 5 Pa 1000 max current A solinoid emg Parameter 7p o male Es jo jAcsenenksdrd Se jo 57 0 jAccelerationB solinoid sae 0 Deceleration B soinid SS Parameter description Hydraulic configuration IA 0 Nominal current A solinoid IB 0 Nominal current B solinoid R Request for programming List name cu rre
62. uire modifications in the construction of the test stand Detailed info on NI PCIe 6259 see in http sine ni com nips cds view p lang en nid 201814 DIETZ automation GmbH A M V Shashkov e Calibration process is very simple and can be made by the operator The only standard measurement tools are required Review of Specifications Applications Test stand ValveExpert is developed for checking maintenance and adjustment of four way servo and proportional valves Working pressure of the stand is up to 350 bar 5000 PSI and it allows to test flow up to 80 L min 21 Gal min Control Signals A servo or proportional valve under testing can be controlled by voltage or current command signal There are five ranges for control signal 10 10mA 20mA 50mA and x100mA Some high current servo and proportional valves may require a special external current amplifier The build in relays can change polarity of control signal and the coil configurations for two coil electric servo or proportional valves Series Parallel Coil No 1 and Coil No 2 Amplifier for Proportional Directional Control Valves In additional to the standard Voltage Current amplifier the system has a programmable PWM current amplifier PWD 00A 400 form Parker Hannifin Corporation This electronics can drive most of two or one coils proportional directional control valves without position feedback and with maximal current up to 3 5A All parameters can b
63. values for high limit overlay curve Feedback Overlay e Control x values of the overlay curves Feedback min y values for low limit overlay curve Feedback max y values for high limit overlay curve Flow AB Overlay Control x values of the overlay curves AB min y values for low limit overlay curve AB max y values for high limit overlay curve Flow A Test Excel Sheet Flow A Test conditions Supply Pressure System pressure e Offset Offset of the control signal Amplitude Amplitude of the control signal Analysis of the Flow A Curve e A Test The curve belongs 1 or does not belong 0 to the overlay region Line FA x0 Coordinate 0 of the linear approximation Line FA x1 Coordinate x1 of the linear approximation Line FA y0 Coordinate yO of the linear approximation Line FA y1 Coordinate y1 of the linear approximation Hysteresis FA Hysteresis Nonlinearity FA Nonlinearity Min Minimal value FA Max Maximal value Analysis of the Spool position Curve e Spool Position 3 Test The curve belongs 1 or does not belong 0 to the overlay region Line SP3 x0 Coordinate 0 of the linear approximation Line SP3 x1 Coordinate x1 of the linear approximation Line SP3 y0 Coordinate yO of the linear approximation Line SP3 y1 Coordinat
64. w test gt R Figure 38 Test of the flow between control port A and return port R Hydraulic schema Flow test gt R Figure 39 Test of the flow between control port B and return port R M V Shashkov Measurement Instruments measurement instruments see Figure 40 Figure 45 are software adjustable Operator can calibrate the devices change physical units and limits Figure 43 Supply pressure gauge Figure 44 System flow meter TE NA 8 ep UR 8 fe 42 10 AM Figure 42 Gauge for differential pressure Figure 45 Multi meters show signal from the between control ports A and B spool position transducer and the control signal DIETZ automation GmbH 22 M V Shashkov Settings for the Automatic Test Current date Subtests of the automatic test IK TII Te fi ES ESS xample information Direct Drive Valve arker Hannifin Corporation M V Shashkov Figure 46 General settings for the automatic test Supply pressure 0 Amplitude Trigger level Left trigger point Right trigger point Speed at low gain Speed at high gain 2 IL T Figure 47 Parameters for the Differential Pressure and Leakage test Supply pressure 70 Ampli MUS Trigger level Speed at low flow Speed at low flow Figure 48 Parameters of the Flow test DIETZ automation GmbH Supply pressure Amplitude Speed a

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