PZ 113E User Manual E-802 Servo-Controller Submodule
Contents
1. sseeesesssesesesssssssssessss 11 2 8 1 Equipment Needed for Calibration sssssessssss 11 2 8 2 Preparations eise ineine eaen a e eea aaa AE a E a aea 11 2 8 3 Zero Point Adjustment eene 12 2 8 4 Static Gain Adjustment saos cometer eta tet tet afe ture be tas 12 2 9 Dynamic Gallbratlon debe ende ebbe tei ea tisneg 13 2 9 1 Finding Resonant Frequency and Setting Notch Filter 13 2 9 2 Step Response Optimization Empirical Method 13 2 9 3 Step Response Optimization Calculation Method 15 2 9 4 Sizing Oomporiefils us actus attese enti pea beri pae ONE R MERE RES 16 2 9 5 Applying Calculated Values in the Circuit 16 E 802 50 E 802 51 E 802 52 ssssesss 17 3 1 E 802 50 Board Description ccccccccccccecccececeeeeeeeeeeeeeeeeeees 17 3 1 1 Component Locations eeesesssessssssssessesseee eene 17 3 1 2 Adj stment COPUOIS coton troie iicet as 17 3 1 3 Block Diagram uror Lene ee tur pu on Sete a tay does 17 3 1 4 Notch Filt r Setting eco ic o emea atate te tete taste oet ouem Ue rufen 17 3 2 E 802 51 E 802 52 Board Description 18 3 2 1 Component Locations eeesseeesessssssssesseseeeee nenne 18 3 2 2 Adjustment Controls due iue treten te tatebtes 18 3 2 32. If PI has sufficient information about your application your PZT system will be shipped ready for operation Only the zero point will have to be realigned from time to time to compensate for temperature changes Further adjustments are not required as long as system components are not replaced or modified Since open loop sensor zero and range adjustment does not involve the servo control module it is described in detail in the other manuals accompanying this system The PZT actuator has to be calibrated in conjunction with the individual device and submodule to which it is connected both devices then belong together Replacement of either one or the other requires new calibration run to get the specified system accuracy Equipment Needed for Calibration For adjustment of the zero point a voltmeter is required Static displacement calibration requires an external expansion gauge with 0 1 um resolution and a precision voltmeter A special extension adapter may be required if your installation does not allow access to the potentiometers that need to be adjusted while the unit is in operation Dynamic calibration procedures require an oscilloscope a digital storage oscilloscope is recommended frequency generator to output square and sine functions from 1 Hz to 1 kHz an ohmmeter with a range from 0 1 to 100 k ohm and depending on the installation a 32 pin extension adapter board to allow access to the trim potentiometers while
3. If the system is set up for computer control it may be possible to substitute the wave generators D to A and A to D converters there for some of the equipment mentioned above Preparations Mount the PZT actuator in exactly the same way and with the same load as during normal operations in the application Release 1 4 0 WWW pi wSs Page 24 3 7 3 3 7 4 E 802 Servo Control Submodule User Manual PZ 113E Zero Point Adjustment Correct zero point adjustment allows the PZT to be used within the full displacement range without reaching the output voltage limits of the amplifier A proper zero point calibration ensures that in closed loop operation the full output voltage swing of the amplifier can be used and prevents overflow conditions Procedure 1 Adjust the sensor zero point while servo mode is OFF as described in the manual for the controller desktop unit module or OEM board on which the E 802 is installed 2 Set servo mode to SERVO ON and make sure that the control input voltage is set to the value target position which is to correspond to 0 V PZT operating voltage Normally this control input voltage value is 0 V 3 Connect a voltmeter to the output socket for the PZT operating voltage Readjust the PZT operating voltage to 0 V using the ZERO potentiometer Static Gain Adjustment The objective of the static servo loop adjustment procedure is to ensure that the PZT actuator expands to its nominal expan
4. set required rise time using P1 watch PZT voltage and sensor values Typical curve at positive input step U TP1 OV E LJ t After the rise time the input voltage must be reached For fast applications remove jumper X1 Note This stage inverts the input signal Test point TP2 comparison point servoON only After settling this voltage must be zero Note A permanent voltage indicates that somewhere in the servo loop there is an undesireable limitation amplifier PZT sensor or controller Typical curve at positive input signal step U TP2 OV Release 1 4 0 WWW pi ws Page 9 E 802 Servo Control Submodule User Manual PZ 113E Test point TP4 Notch Servo ON only Time response at input step depends on setting example U TP4 Test Criterion Final value equals input signal 2 7 Pinouts The connectors J1 and J2 of all E 802 versions are pin compatible except as noted Connector J1 Pin Signal LED K LED A GND GND VC EC VC EC Actual value Actual value VEE 0 VEE OONDABRWDND Connector J2 Meaning Overflow LED cathode normally 0 V overflow Overflow LED anode normally always 5 V OV OV Set servo OFF ON Set servo OFF ON Current position 0 10 V Current position 0 10V 15V 15V Pin Signal 1 CTRL OUT Servo controlled output 2 to 12 V 2 ONT On target within 0 19 of range of target TTL active low 3 COMMAND Target 0 10 V 4 OFL Overflow
5. TTL active low 5 VCC 15 V 6 VCC 15 V 7 VEE 15 V 8 VEE 15 V 9 GND OV 10 GND OV Release 1 4 0 Wwww pi ws Page 10 E 802 Servo Control Submodule User Manual PZ 113E 2 8 Servo Loop Calibration 2 8 1 2 8 2 Static servo loop calibration makes it possible to accurately drive the PZT system to absolute positions in closed loop mode with an external analog control signal ranging from 0 to 10 volts This signal can either be input directly or it can be generated by computer control electronics in the system e g E 816 Computer Interface and Command Interpreter Static servo calibration establishes the relationship between a sensor input of 10 V and the voltage necessary to drive the PZT to its nominal expansion Dynamic servo loop calibration optimizes step response and suppresses resonance overshoot and oscillation see section 2 9 beginning on page 13 Dynamic performance of the PZT system is determined by the maximum output current of the amplifier and by the mechanical properties of the PZT mechanics like moving mass damping and resonant frequencies In order to match the circuitry and the mechanical characteristics to achieve the desired performance the system has to be adjusted for both static and dynamic operations The full calibration and adjustment procedure includes adjustment of the zero point sensor gain slew rate and step response All these basic adjustments are done in our lab before shipment
6. 4 I I 950 3100 OFF FEE TEHE ON switches OFF LETT OFF Release 1 4 0 WWW pi ws Page 7 E 802 Servo Control Submodule 2 4 2 Damping User Manual PZ 113E The damping setting is with S1 settable with a small screwdriver 2 E P5 P4 SI P PS BERI P2 PI XI TT S1 Setting S e circle Is i Value 20 dB 20 dB 25 dB 2 5 Voltage Ranges and Over Voltage Recognition Settings Nominal Voltage Actual Voltage Range V Range V 2010 4120 to 120 301k0 kQ NV INV 0to100 to100 14 0KQ 13 0KQ Cadde 1000 to 0 EIL MM 3 E M i ee HII 750 to 250 790 to 265 7 15 KQ 10 5 KQ 12 4 kQ HIII 500 to 500 560 to 560 9 53 kQ 11 0 KQ 9 53 kO HIV 250 to 750 265 to 790 12 4 KQ 10 5 KQ 7 15 KQ HV 0 to 1000 3 to 1120 14 7 kO 11 3 kO 4 02 kQ Table 1 E 802 55 component substitution chart for voltage ranges and over voltage recognition More precise adjustments are not possible here as the reference voltage is derived from the operating voltage which can vary by about 196 from the nominal value The same tolerance has to be taken into account regarding over voltage recognition Release 1 4 0 www pi ws Page 8 2 6 E 802 Servo Control Submodule User Manual PZ 113E Test Points Test point TP1 Slew Rate Servo ON and OFF for location see figure on p 6
7. Section 3 8 2 can be used Servo loop parameters depend on each and every component used in the system Amplifier PZT actuator and sensor have to be treated as a complete system and the best way to determine the system servo parameters is the use of a simulation program If no simulation program is available typical assumptions can be made in order to get stable servo parameters not optimized but good enough to work with Proportional term amp 0 3 rd 2f Example fres 330 Hz gt T 0 48 ms Integration time T Note If the PZT resonant frequency is above 1 kHz the system bandwidth is limited by the amplifier and the sensor In no case should a higher frequency be used Sizing Components P K 274000 4700 T P 47001T 83C 49 0F C4 22 10 F Caro 411 Example Kp 0 3 gt P402 7 75 KQ T 0 48ms gt Pao3 21 35 KQ Applying Calculated Values in the Circuit Case 1 If a software simulation run has already determined the optimized values these values can be set immediately using the corresponding potentiometers Case 2 The following procedure has to be used if the servo parameters are derived from arbitrary values Set potentiometer P401 slew rate limitation to CCW hard stop Set P402 p term to starting value using an ohmmeter 3 Set P403 i term to a value of 130 of the calculated value add 30 to the calculated value 4 Power up the devi
8. The E 802 50 is no longer in production Component Locations Qu x co NI le ma me Sie Q Q S RoRo oad oc a A Aa a 393 Og C40 o OO OO Or Span C414 R406 C401 ST R427 C412 EA oe OPA4131 ST2 C413 R426 For pinouts see p 23 Adjustment Controls P401 Slew rate limit setting must be set to match the amplifier s current supply capability P402 Proportional term of the servo control loop loop gain P403 Integration term of the servo control loop i term P404 Feedforward gain setting of the servo loop Not installed as standard P405 Notch filter Q factor P406 Notch filter frequency must be set to the first resonant frequency of the PZT mechanics For range change extension see C412 C414 C401 Range extension for slew rate rise time standard 47 nF C410 Range extension for integral term not installed as standard R403 Correction of a positive control deviation 0 ohms as standard only on E 802 50 R406 Correction of a negative control deviation O ohms as standard only on E 802 50 R428 R429 R430 Programming of over voltage limits See table p 20 C412 C413 C414 Determine available notch filter frequency range See table p 19 Block Diagram Ref IR Servo Overflow sterence P401 OFF Detection Input A E Slew Rate yd To Amplifier Limiter Notch Filter Sensor Input Notch Filter Setting The frequencies withi
9. VCC 15V 6 VCC 15V 7 VEE 15V 8 VEE 15 V 9 GND OV 10 GND OV Release 1 4 0 WWW pi ws Page 23 E 802 Servo Control Submodule User Manual PZ 113E 3 7 Servo Loop Calibration 3 7 1 3 7 2 Static servo loop calibration makes it possible to accurately drive the PZT system to absolute positions in closed loop mode with an external analog control signal ranging from 0 to 10 volts This signal can either be input directly or it can be generated by computer control electronics in the system e g E 816 Computer Interface and Command Interpreter Static servo calibration establishes the relationship between a sensor input of 10 V and the voltage necessary to drive the PZT to its nominal expansion Dynamic servo loop calibration optimizes step response and suppresses resonance overshoot and oscillation see section 3 8 beginning on page 26 Dynamic performance of the PZT system is determined by the maximum output current of the amplifier and by the mechanical properties of the PZT mechanics like moving mass damping and resonant frequencies In order to match the circuitry and the mechanical characteristics to achieve the desired performance the system has to be adjusted for both static and dynamic operations The full calibration and adjustment procedure includes adjustment of the zero point sensor gain slew rate and step response All these basic adjustments are done in our lab before shipment If PI has sufficient
10. fmax C414 C413 C412 R426 R427 F4o C414 C413 C412 R426 R427 Fio Hz Hz nF nF kQ kQ Hz nF nF kQ kQ Hz 40 90 100 820 22 22 6 57E 5 33 1500 47 47 8 00E 5 90 220 47 220 22 22 3 96E 6 18 2 2 680 47 47 3 92E 6 190 490 18 150 22 22 2 00E 7 6 8 2 2 330 47 47 1 81E 7 300 750 8 2 2 2 100 22 22 5 20E 7 3 342 2 220 47 47 4 45E 7 610 1600 3 3722 47 22 22 2 08E 8 0 56 2 2 100 47 47 1 95E 8 1600 4100 2 20 18 22 22 1 36E 9 2 20 22 47 47 1 36E 9 3 3 2 E 802 52 Component Values E 802 52 Frequency Range Damping Options 25 dB 20 dB C413 C412 R426 R427 R426 R427 fmin fmax Hz Hz nF nF kQ kQ kQ kQ 38 103 100 100 7 5 13 22 27 80 219 47 47 7 5 13 22 27 171 467 22 22 7 5 13 22 27 377 1028 10 10 7 5 13 22 27 802 2188 4 7 4 7 7 5 13 22 27 1712 4674 2 2 2 2 7 5 13 22 27 Release 1 4 0 www pi ws Page 19 E 802 Servo Control Submodule User Manual PZ 113E 3 4 Voltage Ranges and Over Voltage Recognition Settings Nominal Voltage Actual Voltage R428 R429 R430 we IV Range V LILL NEN 1120 to 3 4 02 kQ 11 3 kQ 14 7 kQ HIII 500 to 500 560 to 560 Table 1 E 802 5x component substitution chart for voltage ranges and over voltage recognition More precise adjustments are not possible here as the reference voltage is derived from the operating voltage which can vary by about 196 from the nominal value The same tolerance has to be taken into account regarding
11. information about your application your PZT system will be shipped ready for operation Only the zero point will have to be realigned from time to time to compensate for temperature changes Further adjustments are not required as long as system components are not replaced or modified Since open loop sensor zero and range adjustment does not involve the servo control module it is described in detail in the other manuals accompanying this system The PZT actuator has to be calibrated in conjunction with the individual device and submodule to which it is connected both devices then belong together Replacement of either one or the other requires new calibration run to get the specified system accuracy Equipment Needed for Calibration For adjustment of the zero point a voltmeter is required Static displacement calibration requires an external expansion gauge with 0 1 um resolution and a precision voltmeter A special extension adapter may be required if your installation does not allow access to the potentiometers that need to be adjusted while the unit is in operation Dynamic calibration procedures require an oscilloscope a digital storage oscilloscope is recommended frequency generator to output square and sine functions from 1 Hz to 1 kHz an ohmmeter with a range from 0 1 to 100 k ohm and depending on the installation a 32 pin extension adapter board to allow access to the trim potentiometers while the board is in operation
12. loop there is an undesireable limitation amplifier PZT sensor or controller Typical curve at positive input signal step U A2 OV Release 1 4 0 WWW pi ws Page 21 E 802 Servo Control Submodule User Manual PZ 113E Test point A3 Integrator Servo ON only typical curve at positive input step U A3 Test Criterion Voltage within the limits max 9 5 V U A3 12 5 V typ allowed input range of the amplifier Servo OFF Voltage equals the input voltage Test point A4 Controller Servo ON only Test Criterion Sum signal of test point A3 and test point A2 inverted Test point A5 Notch Servo ON only Time response at input step depends on setting Example U A5 Test Criterion Final value equals input signal Release 1 4 0 WWW pi ws Page 22 E 802 Servo Control Submodule User Manual PZ 113E 3 6 Pinouts The connectors J1 and J2 of all E 802 versions are pin compatible except as noted Connector J1 Pin Signal LED K LED A GND GND VC EC VC EC Actual value Actual value VEE 0 VEE OONDABRWDND Connector J2 Meaning Overflow LED cathode normally 0 V overflow Overflow LED anode normally always 5 V OV OV Set servo OFF ON Set servo OFF ON Current position 0 10 V Current position 0 10V 15V 15V Pin Signal 1 CTRL OUT Servo controlled output 2 to 12 V 2 SERVO OFF ON switching 3 COMMAND Target 0 10 V 4 OFL Overflow TTL active low 5
13. over voltage recognition 3 5 Additional Adjustment and Test Points These adjustment elements and test points are not used during the standard calibration procedures Slew rate adjustment range too small rise time to short install C401 22 100 nF and or change R407 SMD Standard 1 kQ Proportional term too small servo loop too slow increase P402 potentiometer type Bourns 90 Standard 50 kQ increase R416 SMD Standard 470 Q Proportional term too large decrease P402 10 kQ 5 kQ Potentiometer Bourns 90 Standard 50 kQ Integral term to small settling time too long install C410 wired RM 2 5 22 100 nF Integral term too large decrease P403 20 kQ 10 kQ Standard is 50 kQ Servo loop too slow despite optimal setting install P404 20 kQ adjust for best compromise of rise time and overshoot Notch Filter range of potentiometer too small see instructions for notch filter range setting Release 1 4 0 WWW pi wSs Page 20 E 802 Servo Control Submodule User Manual PZ 113E Test point A1 Slew Rate Servo ON and OFF set required rise time watch PZT voltage and sensor values Typical curve at positive input step U A1 OV U A1 f t P402 REEL rr t After the rise time the input voltage must be reached Note This stage inverts the input signal Test point A2 comparison point servoON only After settling this voltage must be zero Note A permanent voltage indicates that somewhere in the servo
14. 3E Step Response Optimization Calculation Method Either this method or the empirical method described in Section 2 9 2 can be used Servo loop parameters depend on each and every component used in the system Amplifier PZT actuator and sensor have to be treated as a complete system and the best way to determine the system servo parameters is the use of a simulation program If no simulation program is available typical assumptions can be made in order to get stable servo parameters not optimized but good enough to work with Proportional term K 0 3 zu 2A M Example fres 330 Hz gt T 0 48 ms Integration time T Note Ifthe PZT resonant frequency is above 1 kHz the system bandwidth is limited by the amplifier and the sensor In no case should a higher frequency be used Release 1 4 0 www pi ws Page 15 2 9 4 2 9 5 E 802 Servo Control Submodule User Manual PZ 113E Sizing Components P K 274000 4700 f 1 4T00 T 5 C 222 10 F C 222 10 F 37 Ci t C Example Kp 0 3 gt P2 7 75 KQ T 0 48ms gt P3 10 44 KQ Applying Calculated Values in the Circuit Case 1 If a software simulation run has already determined the optimized values these values can be set immediately using the corresponding potentiometers Case 2 The following procedure has to be used if the servo parameters are derived from arbitrary values Set potentiometer P1 slew rate limitat
15. Block DIagrP atris oo locke De neca b nta tete treaties academies 18 Release 1 4 0 www pi ws Page 1 E 802 Servo Control Submodule User Manual PZ 113E 3 2 4 Notch Filter Settings Aseissa nea tag pee ade ede denies 18 3 3 Notch Filter Range Extension Component Tables 19 3 3 1 E 802 50 and E 802 51 scatet i bere oo EN Deb Os 19 3 3 2 E 802 52 i a M 19 3 4 Voltage Ranges and Over Voltage Recognition Settings 20 3 5 Additional Adjustment and Test Points sss 20 3 6 PIhouts iiie e t e rade Ne Pe NE cheated 23 3 7 Servo Loop Calibration eeeeeseesssssssesssesssssssss 24 3 7 1 Equipment Needed for Calibration sssssessssss 24 3 7 2 Preparations irte tse tci src tra te uL effets qe ba deccad tags 24 3 7 3 Zero Point Adjustment ere teen ens 25 3 7 4 Static Gain Adjustment seesee 25 3 8 Dynamic Calibration ario faites ten ptt e etaim cote easels 26 3 8 1 Finding Resonant Frequency and Setting Notch Filter 26 3 8 2 Step Response Optimization Empirical Method 26 3 8 3 Step Response Optimization Calculation Method 28 3 8 4 Sizing Components 2 dco redes dodi dune iu detect eee 28 3 8 5 Applying Calculated Values in the Circuit 28 Copyright 2004 by Physik Instrumente PI GmbH amp Co K
16. G Release 1 4 0 File E 802UserPZ113E140 doc 1120256 Bytes Release 1 4 0 www pi ws Page 2 E 802 Servo Control Submodule User Manual PZ 113E 0 Safety Precautions CAUTION E 802 submodule boards are ESD sensitive electrostatic discharge sensitive devices Observe all precautions against static charge buildup before handling these devices Avoid touching circuit components pins and PCB traces Discharge any static charge you may have on your body by briefly touching a conductive grounded object before you touch any electronic assembly Pose PCBs only on conductive surfaces such as ESD safe transport containers envelopes foam Electronic subassemblies must always be kept and transported shipped in conductive packaging Make sure that no conductive particles of any kind metallic dust or shavings broken pencil leads loose screws get on the card CAUTION Calibration of the controller the E 802 is a part of is done prior to delivery by the manufacturer Do not adjust potentiometers unnecessarily Only the zero point will have to be realigned from time to time to compensate for temperature changes Further adjustments are not required as long as system components are not replaced or modified Any calibration procedures are to be carried out by qualified authorized personnel only CAUTION Some adjustment elements on the main board of the controller and on E 802 submodules are covered with sealing lacquer Damage to
17. PZ 113E 3 8 Dynamic Calibration 3 8 1 3 8 2 A summary of the equipment needed for calibration can be found in section 3 7 1 on page 24 Finding Resonant Frequency and Setting Notch Filter Evaluate the resonant frequency of the actuator while installed at the operation site For this purpose a square wave is applied to the input with servo control set to OFF 10 Hz 1 Vpp use DC offset 0 5 V if bipolar Connect the sensor monitor output with one channel of the oscilloscope and watch the step response The resonant frequency of the system can be estimated by the induced oscillations If for example the period of the oscillation is 3 ms then the resonant frequency is 1 period length or 1 3 ms 0 33 kHz or 330 Hz Based on this frequency the dimensioning of the notch filter can be found in the tables in section 3 3 p 19 Note that it may be necessary to add or change some components Step Response Optimization Empirical Method Either this method or the calculation method described in Section 3 8 3 can be used Standard Tuning For dynamic operation the step response of the mechanical system is important The amount of damping and overshoot can be optimized by tuning the differential and integral term of the amplifier Either the empirical or the calculating method can be used Procedure 1 Mount the PZT exactly as it will be operated 2 Set Servo ON 3 Use a square wave function generator and supply the inpu
18. Piezo Nano Positioning PI PZ 113E User Manual E eJ C c Servo Controller Submodule Release 1 4 0 Date 2004 09 16 This document describes the following Product s B E 802 50 Servo Control Submodules B E 802 51 Servo Control Submodules B E 802 52 Servo Control Submodules B E 802 55 Servo Control Submodules Physik Instrumente PI GmbH amp Co KG Auf der R merstr 1 76228 Karlsruhe Germany Tel 49 721 4846 0 Fax 49 721 4846 299 Moving the NanoWorld www pi ws info pi ws www pi ws E 802 Servo Control Submodule User Manual PZ 113E Table of Contents Safety Precaullons inssaesveista ci sake skate baee etri a E ERIS 3 PERO GUC COIN aioe sonet pe RenDEPGnEEODE DNE DUE 4 1 1 Functionality eR PEE 4 1 2 Model S mmani tede doen deca i e eoi bo LA iuda ates 5 E 802 55 saco dpud muda dtt eee 6 2 1 Component Locations sess 6 2 2 Adjustment GOnlrols rcr ea deed ato ce rer e due 6 2 3 Block DIBQEIaTE eicit ecu eoi te ler te te vtt aeaa tn ien 7 24 Notch Filler Setting S aee taedia uoto t bind ecu NE NEAN ete 7 2 4 1 SEIN C 5 dutiiduesbutetpb etae t ne A Ghia ae iGees thats 7 2 4 2 DAMPING e eencaneniaceee acedeaeeeereeeueecdeseeen 8 2 5 Voltage Ranges and Over Voltage Recognition Settings 8 2 6 Test POMS soc eas e a oe nde dade att ene E 9 2 7 Pinouts ix ete erase arb tb e rt E ER eie e bra beiden 10 2 8 Servo Loop Calibration
19. ce and set SERVO ON If you hear oscillation noise set SERVO OFF immediately Verify all values you have set 5 Apply a square wave signal 10 Hz 10 Vpp 5 V Offset to the input Release 1 4 0 Wwww pi ws Page 28 6 10 E 802 Servo Control Submodule User Manual PZ 113E Turn potentiometer P403 i term CW until a significant overshoot can be seen 2 to 5 Adjust P406 notch filter so that resonance effects and overshooting are optimally damped Depending on the application set P403 either for optimized settling or to allow an overshoot of 5 to 10 The latter choice provides a larger bandwidth Turn P401 slew rate limitation CW until the wobble comes to a minimum without increasing the rise time significantly Apply a sine wave with variable frequency 10 Vpp 5 V offset Check the sensor reading for amplitude and signal shape starting at 10 Hz up to the resonant frequency If needed repeat steps 8 and 9 If the bandwidth is too small increase the i term This also increases the overshoot amplitude for a step response If signal distortions are already noticeable well below the resonant frequency decrease the i term o Release 1 4 0 www pi ws Page 29
20. ds to its nominal expansion when the control signal input is 10 V Preparations An adjustable voltage source from 0 to 410 0000 V and a displacement gauge with 0 1 um resolution is needed Procedure 1 Make sure that any DC offset is set to zero or disabled see main board manual Set SERVO ON mode 3 Check whether the PZT oscillates If it does you can t miss hearing it and dynamic gain adjustments have to be done prior to continuing with static gain adjustment 4 Apply 0 V to the CONTROL INPUT 5 Adjust the external position probe and set the expansion reading to zero 6 Command a position equal to the nominal expansion i e apply 10 V to the CONTROL INPUT The external gauge should show the PZT at nominal expansion and the sensor monitor output should be 10 V 7T To adjust the sensor monitor output to exactly 10 000 V use the P6 GAIN Fine Adjust potentiometer on the E 802 55 servo submodule 8 To adjust the expansion without changing the sensor monitor output servo control is on use the gain adjustment potentiometer on the E 801 x sensor module Repeat the last steps several times until stable results are achieved In some cases e g with the E 651 controller amplifier for closed loop bender actuators the PZT operating voltage has to be 0 V if the control input voltage is 5 V With bender actuators a non contact measuring method must be applied Release 1 4 0 Wwww pi ws Page 12 E 802 Serv
21. ersions E 802 55s leave notch filter and slew rate functions turned on when servo control is turned off They also have a mini DIP switch for selection of notch filter frequency ranges so that component replacement is not necessary For revision ADC or higher see User Manual PZ 150E The following sections describe version specific features Be sure to locate the section that corresponds to the version you have Release 1 4 0 WWW pi wSs Page 5 E 802 Servo Control Submodule User Manual PZ 113E 2 E 802 55 The 802 55 is currently replacing the earlier versions With the E 802 55 the notch filter and slew rate limiter are also active even when the servo mode TTL input line is at the servo OFF level open loop operation Note In open loop mode the gain may vary by a value in the range of 3 to 6 depending on the setting of P5 drift compensation potentiometer see figure below By default P5 is preset to its mid position 2 4 Component Locations ge P5 PA SI T I n3 2 1 TOIT aro e Sez b E o o T ood eg 2008 P3 P2 P1 XI TT For pinouts see p 10 For element description see P1 to P6 S1 S2 X1 see below R9 to R11 on p 8 TP1 TP2 and TP4 on p 9 C10 C11 on p 16 2 2 Adjustment Controls P1 Slew Rate Limitation P2 Loop Gain P Term P3 Integration Time Constant I Term P4 Notch Frequency P5 Drift Compensation P6 Sensor Gain Fine Adjust X1 Slew Rate Ra
22. ion to CCW hard stop Set P2 p term to starting value using an ohmmeter 3 Set P3 i term to a value of 130 of the calculated value add 30 to the calculated value 4 Power up the device and set SERVO ON If you hear oscillation noise set SERVO OFF immediately Verify all values you have set 5 Apply a square wave signal 10 Hz 10 Vpp 5 V Offset to the input 6 Turn potentiometer P3 i term CW until a significant overshoot can be seen 2 to 596 7T Adjust P4 notch filter so that resonance effects and overshooting are optimally damped 8 Depending on the application set P3 either for optimized settling or to allow an overshoot of 5 to 10 96 The latter choice provides a larger bandwidth 9 Turn P1 slew rate limitation CW until the wobble comes to a minimum without increasing the rise time significantly 10 Apply a sine wave with variable frequency 10 Vpp 5 V offset Check the sensor reading for amplitude and signal shape starting at 10 Hz up to the resonant frequency If needed repeat steps 8 and 9 If the bandwidth is too small increase the i term This also increases the overshoot amplitude for a step response If signal distortions are already noticeable well below the resonant frequency decrease the i term Release 1 4 0 WWW pi wSs Page 16 3 E 802 Servo Control Submodule User Manual PZ 113E E 802 50 E 802 51 E 802 52 3 1 E 802 50 Board Description 3 1 1 3 1 2 3 1 3 3 1 4
23. ity can be adjusted by trim potentiometers e Servo function can be enabled disabled via TTL signals low servo ON high servo OFF Excellent long term stability is accomplished by using exclusively low tolerance low drift components Residual errors in the range of 0 05 can be compensated with additional trimming components The location of the E 802 on the board on which it is installed is indicated in the User Manual for that board e g the E 621 This manual describes those functions and procedures specific to the E 802 Release 1 4 0 www pi ws Page 4 E 802 Servo Control Submodule User Manual PZ 113E 1 2 Model Summary Note that only the E 802 55 revision ADC or higher which is described in the separate manual PZ 150E is in production This document PZ 113E describes the earlier E 802 55 versions and the versions E 802 50 E 802 51 and E 802 52 which are pin compatible to E 802 55 and may still be encountered in some equipment E 802 50 first version E 802 51s have an additional adjustment potentiometer P407 for fine adjustment of the monitor output E 802 52s have an additional potentiometer for fine adjustment of dynamic properties An additional time constant allows compensating the position error caused by PZT creeping effects Settling times can be reduced significantly by these procedures With this module notch Q factor adjustment is no longer required E 802 55 in contrast to earlier v
24. n a frequency range can be set with potentiometer P406 Alternate extended frequency ranges can be attained by component substitution The ranges and component values are given in the table on p 19 Release 1 4 0 Wwww pi ws Page 17 E 802 Servo Control Submodule 3 2 E 802 51 E 802 52 Board Description 3 2 1 3 2 2 3 2 3 3 2 4 Component Locations User Manual PZ 113E Q 0 o P40 P OPA4131 R427 C412 ST1 C413 For pinouts see p 23 Adjustment Controls C40 oo P404 C414 319 P403 P407 R430 393 P402 P401 R428 R429 DOG C401 P OPA4132 ST2 R426 Slew rate limit setting must be set to match the amplifier s current supply Proportional term of the servo control loop loop gain Integration term of the servo control loop i term Feedforward gain setting of the servo loop Not installed as standard E 802 51 notch filter Q factor E 802 52 PZT drift compensation fine adjustment Notch filter frequency must be set to the first resonant frequency of the PZT mechanics For range change extension see C412 C414 P401 T capability P402 K P403 Ti P404 Kr P405 Tp P406 fn P407 Ks C401 C410 R428 R429 R430 C412 C413 C414 Block Diagram Reference TR Servo Overflow Input P401 OFF Detection Slew Rate Pe To Amplifier Limiter ON KF Ki Ti FN To ds P402 P403 P406 P405 s TPE Notch Ks Fi
25. ne Filter Sensor P407 diust D Notch Filter Settings Adjustment of output monitor E 802 52 only Range extension for slew rate rise time standard 47 nF Range extension for integral term not installed as standard Programming of over voltage limits See table p 20 Determines available notch filter frequency range See tables p 19 T Slew rate limitation Proportional term T Integration time constant fn Notch filter Kr Feed forward option usually not used Tp Drift time constant E 802 52 only P405 on E 802 51 adjusts notch filter Q factor but on E 802 52 the drift compensation The frequencies within a frequency range can be set with potentiometer P406 Alternate extended frequency ranges can be attained by component substitution The ranges and component values are given in the tables on p 19 Release 1 4 0 www pi ws Page 18 E 802 Servo Control Submodule 3 3 Notch Filter Range Extension Component Tables User Manual PZ 113E Versions E 802 50 and E 802 52 require component substitution to obtain different notch filter setting ranges The frequencies within indicated frequency ranges can be set with potentiometer P406 3 3 4 E 802 50 and E 802 51 Frequency Component Values E 802 50 and E 802 51 Range Damping Options 25 dB 20 dB fmin
26. nge S1 Notch Filter Damping S2 Notch Filter Range Release 1 4 0 www pi ws Page 6 E 802 Servo Control Submodule User Manual PZ 113E 2 3 Block Diagram P1 Slew Servo B P5 Time xt OFF S2 Control Output argel p gt t pum e To Amplifier Ea i a D gt p Slew Rate Limiter ON Notch Drift see Filter Compens note d P2 Overflow Detection e Loop Gain Integrator Sensor P6 Value D mL BE Gain Fine Adjust On Target Detection E 802 55 Block Diagram Note The servo ON OFF switch is controlled by electrical signals from the board on which the submodule is installed 2 4 Notch Filter Settings The frequencies within a frequency range can be set with potentiometer P4 Alternate extended frequency ranges are available with the mini DIP switches S2 as shown in the table below contact PI for latest information on possible changes 2 4 1 Range Range Mini DIP Switch Block S2 P4 Min Notch P4 Max Notch Number switch slider shown in black Frequency in Hz Frequency in Hz ON 1 ii ji 40 130 OFF man ON EDEN 2 i i 120 380 OFF ENN M ON i 3 i 340 1100 OFF ERN TE ON
27. o Control Submodule User Manual PZ 113E 2 9 Dynamic Calibration 2 9 1 2 9 2 A summary of the equipment needed for calibration can be found in section 2 8 1 on page 11 Finding Resonant Frequency and Setting Notch Filter Evaluate the resonant frequency of the actuator while installed at the operation site For this purpose a square wave is applied to the input with servo control set to OFF 10 Hz 1 Vpp use DC offset 0 5 V if bipolar Connect the sensor monitor output with one channel of the oscilloscope and watch the step response The resonant frequency of the system can be estimated by the induced oscillations If for example the period of the oscillation is 3 ms then the resonant frequency is 1 period length or 1 3 ms 0 33 kHz or 330 Hz Based on this frequency the dimensioning of the notch filter can be found in the table on page 7 Step Response Optimization Empirical Method Either this method or the calculation method described in Section 2 9 3 can be used Standard Tuning For dynamic operation the step response of the mechanical system is important The amount of damping and overshoot can be optimized by tuning the differential and integral term of the amplifier Either the empirical or the calculating method can be used Procedure 1 Mount the PZT exactly as it will be operated 2 Set Servo ON 3 Use a square wave function generator and supply the input with a square wave of 5 Vpp if bipolar se
28. sion when the control signal input is 10 V Preparations An adjustable voltage source from 0 to 10 0000 V and a displacement gauge with 0 1 um resolution is needed Procedure 1 Make sure that any DC offset is set to zero or disabled see main board manual Set SERVO ON mode 3 Check whether the PZT oscillates If it does you can t miss hearing it and dynamic gain adjustments have to be done prior to continuing with static gain adjustment 4 Apply 0 V to the CONTROL INPUT Adjust the external position probe and set the expansion reading to zero 6 Command a position equal to the nominal expansion i e apply 10 V to the CONTROL INPUT The external gauge should show the PZT at nominal expansion and the sensor monitor output should be 10 V 7 To adjust the sensor monitor output to exactly 10 000 V use the GAIN Fine Adjust potentiometer on the servo submodule E 802 5x 8 To adjust the expansion without changing the sensor monitor output servo control is on use the gain adjustment potentiometer on the E 801 x sensor module Repeat the last steps several times until stable results are achieved In some cases e g with the E 651 controller amplifier for closed loop bender actuators the PZT operating voltage has to be 0 V if the control input voltage is 5 V With bender actuators a non contact measuring method must be applied Release 1 4 0 WWW pi ws Page 25 E 802 Servo Control Submodule User Manual
29. t DC offset to 2 5 V and a frequency of 5 to 10 Hz Connect an oscilloscope to the monitor output 5 Adjust P2 until resonant frequency becomes apparent 6 Adjust P4 notch filter frequency until the oscillation amplitude becomes a minimum 7 Adjust P2 and P3 alternating to optimize step response Release 1 4 0 WWW pi wSs Page 13 E 802 Servo Control Submodule User Manual PZ 113E The settling curve seen on the scope could look like one of the following Case 1 Large overshoot unstable Case 2 Optimal Case 3 Settling time too long Sensor Monitor Signal Dwg PZTRESP BMP Fine Tuning Target Signal 4 u f B C Dwg step wmf The objective of the drift fine tuning is curve B of the diagram Because the curve is exaggerated a high resolution oscilloscope 12 14 bits is required as well as a precise voltage generator First adjust the step response without overshoot Using P5 drift compensation potentiometer for location see figure on p 6 curve shapes A B and C can be attained If the overshoot can not be eliminated by using P5 the loop gain has to be reduced The result may be different at rising and falling edges so a compromise has to be found By default P5 is preset to its mid position In open loop mode the gain may vary by a value in the range of 3 to 6 depending on the setting of P5 Release 1 4 0 WWW pi wSs Page 14 2 9 3 E 802 Servo Control Submodule User Manual PZ 11
30. t with a square wave of 5 Vpp if bipolar set DC offset to 2 5 V and a frequency of 5 to 10 Hz 4 Connect an oscilloscope to the monitor output 5 Adjust P402 until resonant frequency becomes apparent 6 Adjust P406 notch filter frequency until the oscillation amplitude becomes a minimum Do not confuse with P406 on an E 621 7 Adjust P402 and P403 alternating to optimize step response Release 1 4 0 WWW pi wSs Page 26 E 802 Servo Control Submodule User Manual PZ 113E The settling curve seen on the scope could look like one of the following Case 1 Large overshoot unstable Case 2 Optimal Case 3 Settling time too long Sensor Monitor Signal Dwg PZTRESP BMP Fine Tuning Target Signal 4 O f B C Dwg step wmf The objective of the drift fine tuning is curve B of the diagram Because the curve is exaggerated a high resolution oscilloscope 12 14 bits is required as well as a precise voltage generator First adjust the step response without overshoot Using P405 curve shapes A B and C can be attained If the overshoot can not be eliminated by using P405 the loop gain has to be reduced The result may be different at rising and falling edges so a compromise has to be found Release 1 4 0 WWW pi ws Page 27 3 8 3 3 8 4 3 8 5 E 802 Servo Control Submodule User Manual PZ 113E Step Response Optimization Calculation Method Either this method or the empirical method described in
31. the board is in operation If the system is set up for computer control it may be possible to substitute the wave generators D to A and A to D converters there for some of the equipment mentioned above Preparations Mount the PZT actuator in exactly the same way and with the same load as during normal operations in the application Release 1 4 0 WWW pi ws Page 11 2 8 3 2 8 4 E 802 Servo Control Submodule User Manual PZ 113E Zero Point Adjustment Correct zero point adjustment allows the PZT to be used within the full displacement range without reaching the output voltage limits of the amplifier A proper zero point calibration ensures that in closed loop operation the full output voltage swing of the amplifier can be used and prevents overflow conditions Procedure 1 Adjust the sensor zero point while servo mode is OFF as described in the manual for the controller desktop unit module or OEM board on which the E 802 55 is installed 2 Set servo mode to SERVO ON and make sure that the control input voltage is set to the value target position which is to correspond to 0 V PZT operating voltage Normally this control input voltage value is 0 V 3 Connect a voltmeter to the output socket for the PZT operating voltage Readjust the PZT operating voltage to 0 V using the ZERO potentiometer Static Gain Adjustment The objective of the static servo loop adjustment procedure is to ensure that the PZT actuator expan
32. the seal will void the warranty except in consultation with PI Release 1 4 0 www pi ws Page 3 E 802 Servo Control Submodule User Manual PZ 113E 1 Introduction The E 802 is a small add on printed circuit board PCB that processes the control signal for the power amplifier driving piezoelectric translators Slew rate limitation notch filter and servo control loop are all implemented on the E 802 4 7 t LETT Birra Ray 4 HE 3 of PRIETK i AVE AATTEET Ue eA cage a Ma NN E 802 55 servo control submodule 1 1 Functionality The servo loop logic compares the control voltage input and the position sensor signal to generate the power amplifier input control signal An analog proportional integral P I algorithm is used Slew rate limitation insures that the output signal slope does not exceed the following capability of the power amplifier The notch filter is used to damp out oscillation at the resonant frequency of the mechanics In summary e Slew rate limitation of output signals can be set within the range of 15 V ms up to 1500 V ms Note that these values are only valid for the slew rate limitation circuit The values for the complete system are lower due to limitations given by amplifier notchfilter etc 1 V ms to 500 V ms e P I control performance with individual setting of P and l terms e Optional notch filter allows suppression of mechanical resonances The filter frequency and qual
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