PI E-664 User manual

PZ 99E User Manual
E-664 LVPZT Position Servo Controller
Release: 1.0.4 Date: 2003-10-15
This document describes the
following product(s):
E-664.S3
LVPZT Servo Controller
[email protected]
© Physik Instrumente (PI) GmbH & Co. KG
Auf der Römerstr. 1 ⋅76228 Karlsruhe, Germany
Tel. [phone] ⋅Fax: [phone]
s ⋅www.pi.ws

E-664 LVPZT Position Servo Controller User Manual PZ 99E
Table of Contents :
0. Manufacturer Declarations .............................................. 3
0.1. Declaration of Conformity ............................................................ 3
0.2. Quality and Warranty Clauses ..................................................... 3
0.3. Warnings and Safety Instructions ................................................ 4
1. Introduction....................................................................... 5
2. Quick Start ........................................................................ 6
2.1. Starting Operation........................................................................ 6
2.2. Troubleshooting ........................................................................... 7
3. Operating Modes .............................................................. 7
3.1. Open-Loop (Servo OFF) Mode .................................................... 7
3.2. Closed-Loop (Servo ON) Mode ................................................... 8
4. Block Diagram................................................................... 9
5. Adjustment and Calibration Procedures ...................... 10
5.1. Static Calibration........................................................................ 10
5.2. Main Board Calibration Elements .............................................. 13
5.3. Dynamic Calibration................................................................... 14
6. E-664.S3 Technical Data ................................................ 14
6.1. Frequency Response................................................................. 15
6.2. Electrical Capacitance of Different PI PZTs.............................. 15
7. Front Panel Elements ..................................................... 16
8. Rear Panel Elements ...................................................... 17
8.1. Connectors................................................................................. 18
9. NanoCube Handling ....................................................... 19
© Copyright 2005 by Physik Instrumente (PI) GmbH & Co. KG
Release: 1.0.4
File:E-664_User_PZ99E104.doc, 260608 Bytes
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E-664 LVPZT Position Servo Controller User Manual PZ 99E
0. Manufacturer Declarations
0.1. Declaration of Conformity
The manufacturer,
Physik Instrumente (PI) GmbH & Co. KG
Auf der Roemerstrase 1
D-76228 Karlsruhe, Germany
declares, that the product E-664 LVPZT Servo Controller complies with these
specifications:
EMC: EN55022 (1991), Group1, Class B
EN50082-1 (1992) / IEC 801-2:1991 (4 kV Contact Discharge)
(8 kV Air Discharge)
EN50082-1 (1992) / IEC 801-3: 1984 (3V/m)
EN50082-1 (1992) / IEC 801-4: 1988 (1 kV power lines, 0.5 kV Signal lines)
Safety: IEC 1010-1:1990+A1 / EN61010-1:1993 (Low voltage Directive)
The product complies with the requirements of the EMC Directive 89/336/EEC and CE
markings have been affixed on the devices.
0.2. Quality and Warranty Clauses
Certification
Physik Instrumente (PI) certifies that this product met its published specifications at the
time of shipment. The device was calibrated and tested with the PZT actuators specified in
the product identification table (see below).
Warranty
This Physik Instrumente product is warranted against defects in materials and
workmanship for a period of one year from date of shipment. Duration and conditions of
warranty for this product may be superseded when the product is integrated into (becomes
a part of) other Physik Instrumente products. During the warranty period, Physik
Instrumente will, at its option, either repair or replace products which prove to be defective.
Limitation of Warranty
The foregoing warranty shall not apply to defects resulting from improper or inadequate
maintenance by the Buyer, Buyer supplied products or interfacing, unauthorised
modification or misuse, operation outside of the environmental specifications for the
product, or improper site preparation or maintenance.
The design and implementation of any circuit on this product is the sole responsibility of the
Buyer. PI does not warrant the Buyer's circuitry or malfunctions of PI products that result
from the Buyer's circuitry. In addition, PI does not warrant any damage that occurs as a
result of the Buyer's circuit or any defects that result from Buyer-supplied products.
No other warranty is expressed or implied. Physik Instrumente specifically disclaims
the implied warranties of merchantability and fitness for a particular purpose.
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E-664 LVPZT Position Servo Controller User Manual PZ 99E
0.3. Warnings and Safety Instructions
Warning: High Voltage
Read This Before Operation:
E-664s are amplifiers generating voltages up to 120 V for driving LVPZTs. The
output power may cause serious injury.
When working with these devices or using PZT products from other manufacturers
we strongly advise you to follow general accident prevention regulations.
All work done with and on the devices described here requires adequate
knowledge and training in handling High Voltages. Any cabling or connectors used
with the system must meet the local safety requirements for the voltages and
currents carried.
CAUTION: Calibration Information
If you inform PI about your application, your E-664 will be fully calibrated before
being shipped. It is usually not necessary for you to do anything more than adjust
the zero point before operating the system.
Calibration should only be done after consultation with PI, otherwise internal
configuration settings may be destroyed.
Procedures which involve opening the case are to be carried out by qualified
authorized personnel only.
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E-664 LVPZT Position Servo Controller User Manual PZ 99E
1. Introduction
This manual describes the functionality and the use of
E-664 LVPZT Amplifier / Position Servo Controller
The E-664 is a bench-top device to operate up to three low-voltage piezoelectric
translators (LVPZTs) in open-loop and closed-loop (position controlled) mode. The
E-664 can be used with LVPZTs equipped with strain gauge displacement
sensors. The integrated amplifier can output and sink a peak current of 120 mA
and an average current of 40 mA for each channel.
The E-664 can be operated manually by front panel potentiometers or by external
analog signals.
Fig. 1 E-664 LVPZT Servo Controller
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E-664 LVPZT Position Servo Controller User Manual PZ 99E
2. Quick Start
The E-664 PZT Controller was calibrated with the PZT translators before shipment.
During the calibration process, the expansion of the PZT is compared with an
external standard scale. Individual characteristics of the amplifier and servo-
controller are compensated.
2.1. Starting Operation
1. Being sure not to exceed allowable force limits (see p. 19 for details), mount
the NanoCube mechanics carefully.
2. With the controller powered down, connect the NanoCube to the STAGE
socket.
3. Set the servo switch to OFF and the DC-OFFSET potentiometer counter-
clockwise (CCW) to the hard stop. Switch the display to VOLT.
4. Make sure the power supply is set to allow operation at the proper voltage
range. Two ranges are available: from 100 to120 V and from 220 to240 VAC.
The line fuses need to be replaced when the supply voltage range setting is
changed (see p. 17 for details).
5. Connect the line cord and switch the power on.
6. First watch the VOLT display while turning the potentiometers clockwise. It
should be possible to reach 100 V. Turn the pots back full CCW.
7. Switch display to MICRONS (µm). The values should be close to zero (±20
µm).
8. Switch SERVO to ON. Every channel should now have 0.0, the OTG (on
target) LED should be on, the OFL (overflow) LED off.
9. Turn potentiometers again to maximum. It should be possible to reach 100.0
µm on every channel.
10. If any channel does not operate correctly, switch it to VOLT and see how
much piezo voltage is needed. Typically for 0 to 100 µm, the piezo voltage
should be -5 V to +90 V. If this is not the case, bring the voltage into this
range with the associated ZERO-potentiometer (see
, p. 10 for more details). For large temperature or load changes it is
possible that ZERO needs to be corrected.
Adjustment and
Calibration
The above procedure assures that the system is working correctly in manual
mode.
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2.2. Troubleshooting
No Operation—Display is dark after switching on
Check supply voltage and fuse.
Display in MICRON mode shows no change
Make sure NanoCube is connected and cable is not defective.
Controller runs into overflow when SERVO ON
Bring operation voltage into -5 V to+90 V range with
ZERO potentiometer.
NanoCube oscillates after switching SERVO ON
Switch immediately to SERVO OFF and check mechanical
mounting and servo parameters. If load conditions have been
changed, the mechanical resonant frequency may also have
changed. See the E-802 User Manual for details on resetting the
dynamic characteristics (P- and I-term and notch frequency) It
will be necessary to open the controller case to make these
adjustments.
Warning: High Voltage
Read This Before Operation:
E-664s are amplifiers generating voltages up to 120 V for driving LVPZTs. The
output power may cause serious injury. Only qualified, authorized personnel
should work on or with these devices.
3. Operating Modes
The operating mode is settable independently for each channel and is determined
by the position of the corresponding SERVO toggle switch and the use of the DC
offset potentiometer and CONTROL INPUT terminals.
3.1. Open-Loop (Servo OFF) Mode
3.1.1. Manual Operation
The output voltage can be set by a 10-turn DC Offset potentiometer in the range of
approximately 0 to 100 V. For manual operation CONTROL IN should clamped at
0 V.
3.1.2. External Operation
The output voltage is controlled by an analog signal applied to the CONTROL IN
BNC input ranging from -2 to +12 V. Multiplying by the gain factor of 10, an analog
output voltage range of approximately -20 to +120 V results. The DC-offset
potentiometer can be used to add an offset voltage of 0 to 10 V to the signal input,
effectively shifting its range between -2 to +12 V and -12 V to +2 V.
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3.2. Closed-Loop (Servo ON) Mode
3.2.1. Manual Operation
Displacement of the PZTs can be set by a 10-turn DC-Offset potentiometer in the
range of zero to nominal displacement. For manual operation CONTROL IN should
clamped at 0 V.
3.2.2. External Operation
Displacement of the PZT is controlled by an analog signal in the range of 0 to +10
V, applied to the CONTROL IN BNC input. The controller is calibrated so that 10 V
corresponds to the maximum nominal displacement and 0 V corresponds to zero
displacement. The DC-offset potentiometer can be used to add an offset voltage of
0 to 10 V to the signal input, effectively shifting its range between -2 to +12 V and -
12 V to +2 V.
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4. Block Diagram
Servo-control functions are implemented on an E-802 submodule. The respective
User Manual provides detailed information.
Fig. 2 E-664 block diagram
Note: The potentiometer labelling P1-P5 shown above is that used on the E-802.55-type
plug-in submodules, on which these functions are implemented. Some earlier E-802
versions, while pin-compatible, use different component designations (see the E-802 User
Manual for details).
Zero adjust is front-panel accessible. See the following pages for details.
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E-664 LVPZT Position Servo Controller User Manual PZ 99E
5. Adjustment and Calibration Procedures
CAUTION: If you inform PI about your application,
your E-664 will be fully calibrated before being
shipped. It is usually not necessary for you to do
anything more than adjust the zero point before
operating the system.
Calibration should only be done after consultation
with PI, otherwise internal configuration settings
may be destroyed.
Procedures which involve opening the case are to
be carried out by qualified authorized personnel
only.
For most applications, only the zero point has to be realigned from time to time to
compensate for temperature changes. Further adjustments are not required and
not recommended as long as system components are not exchanged or modified.
Therefore calibration should only be done if the controller/actuator configuration is
changed or elements are replaced.
The full calibration and adjustment procedure includes static calibration (zero point
and sensor gain adjustment) and dynamic calibration (servo-loop, slew rate and
step response).
5.1. Static Calibration
Proper static calibration makes it possible to accurately drive the PZT system to
absolute positions with an external analog control signal running over a 10 V range
and without reaching the output voltage limits of the amplifier and causing overflow
conditions.
Static calibration consists of zero-point adjustment and static gain adjustment The
adjustments are to some degree interdependent and should be repeated until
stable settings are obtained.
Note: Zero-point adjustment is the only calibration operation regularly required in
most application environments.
The following subsections describe the static calibration procedure for one
channel. Note that calibration must be performed separately on each channel.
5.1.1. Zero-Point Adjustment
Proper zero-point adjustment ensures that the full output voltage swing of the
amplifier can be used without reaching the output voltage limits of the amplifier and
causing overflow conditions, both in open-loop and closed-loop operation.
The zero-point is adjusted with the ZERO potentiometer accessible on the front
panel. This potentiometer shifts the output of the sensor processing circuitry and
hence the values on the "Sensor Monitor" and servo-loop sensor-input lines
1 Before powering up the system, make sure the PZT actuator is mounted in the
same way and with the same load as during normal operations in the
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E-664 LVPZT Position Servo Controller User Manual PZ 99E
application. In multi-axis systems, make sure the same PZTs are always
connected to the same controller channels.
2 Make sure the control input is 0 V and the DC offset potentiometer full CCW.
3 Set the switch on the front panel to Servo OFF.
4 Power up the system.
5 Turn the DC-OFFSET potentiometer full clockwise and than back full
counterclockwise (0 V) to exercise the PZT.
6 Adjust the ZERO potentiometer so that the sensor-monitor signal is 0 V. The
zero adjustment is now close enough to allow switching on servo-control.
7 Switch the channel to closed-loop (SERVO ON).
8 Set the display to VOLT.
9 Again using the ZERO potentiometer, adjust the PZT output voltage to approx
-5 V
The zero-point setting is now close enough to allow checking of the PZT output
range
10 Check the PZT output range by applying a voltage which goes from 0 V to +10
V to the CONTROL INPUT and watching the voltage at the PZT.
a) If the output voltage ranges from -10 V to +100V, then zero-point adjustment
is finished.
b) If the output voltage exceeds the range from -10 V to +100 V, the zero point
should be shifted so that the PZT-output voltage range is in the center of the
amplifier output range. For this purpose, return the control input to 0 V and
repeat step 9 using a slightly different value, e.g. -10 V for an LVPZT.
Example: Assume the LVPZT used requires 90 V to achieve the nominal
displacement of 100 µm. Furthermore take into account that the maximum
voltage at the LVPZT should not exceed +100 V in order to maintain a long
lifetime. The E-664 amplifiers have an output range from -20 V to +120 V.
In this case, the zero position PZT voltage can be set within the range from
-10 V to +10 V. Then, the nominal displacement of 100 µm will be reached
with PZT-out in the +80 V to 100 V range., i.e. there is a cushion of ±10 V
available to keep the amplifier from clipping the output when the controller
is within the nominal servo-control range.
5.1.2. Static Gain Adjustment
It should only be necessary to readjust the static gain if system components have
been exchanged or altered.
The objective of static gain adjustment is to ensure that the PZT actuator expands
to its nominal expansion when a control signal input of 10 V is applied (DC-offset
set to 0).
The zero-point must be appropriately set before the static gain adjustment can be
done. This is an iterative process.
The static gain adjustment procedure is as follows:
1 Before powering up the system, make sure the PZT actuator is mounted in the
same way and with the same load as during normal operations in the
application. In multi-axis systems, make sure the PZTs are always connected
to the same controller channels.
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E-664 LVPZT Position Servo Controller User Manual PZ 99E
2 Mount an external gauge to measure the PZT displacement. (with PZT power
amplifier powered down, the external gauge should read 0; if it does not, note
the offset and subtract it from subsequent readings)
3 Set the switch on the front panel to Servo OFF.
4 Make sure the DC-Offset potentiometer is set to zero (full counterclockwise).
5 Power up the system.
6 Adjust the zero potentiometer on the front panel until approx. 0 V is measured
at the sensor monitor connector (rear panel).
7 Scan the voltage at CONTROL INPUT from 0 V to +10 V and read the PZT
displacement using the external gauge. With +10 V the external gauge should
show the PZT at about nominal expansion. Adjust with the sensor gain trim
potentiometer (see Fig. 3).
8 Repeat the previous two steps several times until stable results are obtained.
Sensor gain is now close enough to allow switching servo ON.
9 Switch servo ON.
10 Apply 10.000 V control voltage to the control input.
11 Adjust the sensor monitor signal to exactly 10.000 V using the gain adjustment
potentiometer on the E-802 servo submodule (different versions of this
submodule exist, see the E-802 User Manual for gain adjustment on your unit)
12 Adjust the PZT position to the nominal expansion value using the sensor gain
adjustment (Fig. 3) from step 7. Now, because servo ON, the sensor monitor
value will not change!
13 Repeat the previous two steps until you get stable readings
If the Gain settings have been changed, the zero-point adjustment should be
repeated, and then the static gain rechecked.
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5.2. Main Board Calibration Elements
R152- R154 Sensor Gain R187-R189 Sensor Tolerance
Fig. 3 Adjustment element and submodule locations
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E-664 LVPZT Position Servo Controller User Manual PZ 99E
5.3. Dynamic Calibration
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. Dynamic calibration
optimizes step response and suppresses resonance, overshoot, and oscillation.
These servo-loop, notch filter and slew-rate limitation setting procedures are all
described in detail in the E-802 Servo-Control Submodule User Manual.
6. E-664.S3 Technical Data
Function: Power amplifier and Servo Position controller for
LVPZTs;
Functionality and Parameters optimized for
NanoCube Nano Positioning System.
Channels: 3
Amplifier:
Voltage output range: -20 to +120 V (local mode)
0 to +100 V (remote mode)
Max. output power: 12 W / channel
Average output power: 4 W / channel
Peak output current: 120 mA (for 5 ms)
Current limitation: short circuit proof
Voltage Gain: 10.66 ± 0.1 (open-loop)
Polarity: positive
Control Input Voltage: -2 to +12 V (open-loop)
Input Impedance: 100 kOhm
Position offset setting: 0 to 100V with 10-turn potentiometer
Overflow Detection: Piezo Voltage outside -20..+120V
Display: 3 x 3½ digits, LED, switchable for voltage or
position
Control input socket: BNC and Mini Delta Ribbon
PZT voltage output socket: DSub 25 pin female
Dimensions: 235 x 103 x 288 mm
Weight: 3 kg
Operating Voltage: 90-120/220-240 VAC, 50-60 Hz
Fuse: 0.8 / 1.6A slow
Power: max. 50VA
Power Supply: Linear Regulated for lowest noise
Operating Temperature: 5..40°C
Storage Temperature: -20..+80°C
Humidity: < 75% noncondensing
Position Servo-Control
Sensor Type: Strain Gage Full Bridge
Control Input Voltage: 0 to +10 V (closed-loop for nominal expansion)
Position offset setting: 0 to nominal expansion with 10-turn
potentiometer
Servo Characteristics: P-I-Filter with Notch Filter and Drift
Compensation
Notch Filter Characteristics: 2nd order, damping 25 dB, Frequency 50..500Hz
On-Target Detection: Real Position within ±0.2 µm of Target Position
Sensor Socket: combined with PZT (DSub)
Sensor monitor output socket: BNC and Mini Delta Ribbon
Overflow and On Target Signals: Mini Delta Ribbon, TTL-level
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E-664 LVPZT Position Servo Controller User Manual PZ 99E
6.1. Frequency Response
E-664 open-loop frequency response with various PZT loads. Capacitance values
are in µF.
Fig. 4. Frequency response with a selection of PI PZTs
6.2. Electrical Capacitance of Different PI PZTs
P-810.10 0.5 µF
P-810.20 0.9 µF
P-810.30 1.4 µF
P-840.10 1.8 µF (equal to NanoCube P-611)
P-840.20 3.6 µF
P-840.30 5.4 µF
P-842.60 10 µF
P-844.30 22 µF
P-844.60 45 µF
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E-664 LVPZT Position Servo Controller User Manual PZ 99E
7. Front Panel Elements
Fig. 5. Front panel operating and display elements
VOLTS/MICRONS Toggle switch for LED Display
VOLTS: Display showing current PZT output
MICRONS: Display showing current sensor reading
OFL Overflow LED
OTG On Target LED
ZERO Adjustment potentiometer for operating voltage
ON/OFF Toggle switch for Servo ON / Servo OFF
DC-OFFSET Potentiometer for manual PZT setting
Channel Description For the NanoCube actuators
Ch1 corresponds with mechanical X
Ch2 corresponds with mechanical Y
Ch3 corresponds with mechanical Z
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E-664 LVPZT Position Servo Controller User Manual PZ 99E
8. Rear Panel Elements
Line Switch Power On/Off (opens completely)
Voltage Selector Two default ranges (220-240 V or 110-120 V). Selected
value is visible in window (see figures). Pry out and re-orient
fuse carrier to change range selection. Fuses will also need
to be replaced.
Fuses Fuses are voltage dependent: use 0.8 A for 230 V and 1.6 A
for 110 V (slow type)
Fuse carrier
Door with
window
Line cord
connector
Fuse access
Fig. 6. Fuse access
Stage Connector Single connector for combined piezo actuator and sensor
signals
Control Input Control voltage for open / closed-loop operation
Sensor Monitor Current sensor value
I/O Connector Combines control input, sensor monitor, overflow and on
target signals for all three channels for easy access to
complete functionality. If this connector is used, do not
connect BNC-inputs.
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8.1. Connectors
8.1.1. Piezo Stage Connector (Backpanel)
Fig. 7. Type: Sub-D 25 pin female
Caution: Voltage up to 130 V on pins 11, 12 and 13
8.1.2. I/O Connector (back panel)
Fig. 8. Mini-D ribbon (MDR) connector
Caution: use either BNC inputs or I / O inputs, not both at the same time
Type: 3M / Mini D Ribbon (MDR) .050" / 14 Positions
Order numbers: 101 14 3000VE (plug) and 103 14 52FO008 (casing)
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9. NanoCube Handling
Fig. 9 P-611.3SF and P-611.3OF versions
Fig. 10. P-611.3S and P-611.3O versions