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3 8

AT6250/AT6450 Installation Guide

gain is needed for adequate damping, you can balance the
tracking error by applying velocity feedforward control
(increasing the 

SGVF

 valueÑdiscussed below).

Since the feedback deviceÕs velocity is derived by
differentiating the feedback deviceÕs position with a finite
resolution, the finite word truncation effect

 

and any

fluctuation of the feedback deviceÕs position would be
highly magnified in the velocity value, and even more so
when multiplied by a high velocity feedback gain. When
the value of the velocity feedback gain has reached such a
limit, the motor (or hydraulic cylinder, etc.) will 

chatter

(high-frequency, low-amplitude oscillation) at steady state.

Velocity Feedforward Control (

SGVF

)

The purpose of velocity feedforward control is to improve

tracking performance

; that is, reduce the position error

when the system is commanded to move at constant
velocity. The tracking error is mainly attributed to three
sourcesÑfriction, torque load, and velocity feedback
control (

SGV

).

Velocity feedforward control 

is directed by the Servo Gain

Velocity Feedforward (

SGVF

) setting, which is in turn

multiplied by the rate of change (velocity) of the
commanded position to produce the control signal.
Consequently, because the control signal is now
proportional to the velocity of the commanded position,
the controller essentially anticipates the commanded
position and initiates a control signal ahead of time to
more closely follow (

track

) the commanded position.

Applications requiring contouring or linear interpolation
can benefit from improved tracking performance; however,

if your application only requires short, point-to-point
moves, velocity feedforward control is not necessary.

Because velocity feedforward control is not in the servo
feedback loop (see 

Servo Control Algorithm

 drawing

above), it does not affect the servo systemÕs stability.
Therefore, there is no limit on how high the velocity
feedforward gain (

SGVF

) can be set, except when it

saturates the control output

 (tries to exceed the controllerÕs

analog control signal range of 

±

10V).

Acceleration Feedforward Control
(

SGAF

)

The purpose of acceleration feedforward control is to
improve position tracking performance when the system is
commanded to accelerate or decelerate.

Acceleration feedforward control 

is directed by the Servo

Gain Acceleration Feedforward (

SGAF

) setting, which is in

turn multiplied by the acceleration of the commanded
position to produce the control signal. Consequently,
because the control signal is now proportional to the
acceleration of the commanded position, the controller
essentially anticipates the velocity of the commanded
position and initiates a control signal ahead of time to
more closely follow (

track

) the commanded position.

Same as velocity feedforward control, this control action
can improve the performance of linear interpolation
applications. In addition, it also reduces the time required
to reach the commanded velocity. 

However, if your

application only requires short, point-to-point moves,
acceleration feedforward control is not necessary.

Acceleration feedforward control does not affect the servo
systemÕs stability, nor does it have any effect at constant
velocity or at steady state.

Gain Sets

An added dimension to the control techniques discussed in
the previous section is to group the gains into Ògains setsÓ
that can be invoked to affect motion under certain
conditions.  Gain sets may be useful for applications in
which you would like to invoke different gains a different
portions of a move profile, or at rest, or based on an
external process, etc.

The 

SGSET

 command allows you to save the currently

active gains, control signal offset (

SOFFS

), and maximum

position error (

SMPER

) setting, to a specified gain set (see

list below).

S G P

..........

 Proportional 

Gain

S G V

..........

 Velocity 

Gain

S G I

..........

 Integral 

Gain

SGVF

. . . . . . . .

 

Velocity Feedforward Gain

SGAF

. . . . . . . .

 

Acceleration Feedforward Gain

SGILIM

.....

 

Integral Windup Limit

SOFFS

. . . . . .

 

Servo Control Signal Offset

SMPER

. . . . . .

 

Maximum Allowable Position Error

The gain set saved with the 

SGSET

 command can be

enabled/recalled later with the 

SGENB

 command.  Using

the 

SGENB

 command, the gains can be enabled during

motion at any specified point in the profile, or when not
in motion (see programming example below).

N O T E

The tuning gains saved to a given gain are specific to
the current feedback source (selected with the last 

SFB

command) at the time the gains were saved with the

SGSET

 command.  Later, when you enable the saved

gain set, 

make sure that the gain set you

enable is appropriate to the feedback source
you are using at the time

.

To display the gain values currently in effect, use the

TGAIN

 command.  To display the contents of a particular

gain set, use the 

TSGSET

 command.

Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com

Содержание Compumotor 6000 Series

Страница 1: ...erutilized and idle equipment along with credit for buybacks and trade ins Custom engineering so your equipment works exactly as you specify Critical and expedited services Leasing Rentals Demos In st...

Страница 2: ...D Z Z B B A A 5V SHLD COM SHTNC SHTNO DFT AGND ANI CMD CMD DRIVE 3 TRIGS TRG A GND TRG B GND TRG C GND TRG D GND SHLD OUT A GND OUT B GND OUT C GND OUT D GND SHLD OUTS ENCODER 3 SHLD GND Z Z B B A A 5...

Страница 3: ...North America and Asia Compumotor Division of Parker Hannifin 5500 Business Park Drive Rohnert Park CA 94928 Telephone 800 358 9070 or 707 584 7558 Fax 707 584 3793 FaxBack 800 936 6939 or 707 586 858...

Страница 4: ...enable input ENBL and joystick inputs pins 15 19 on the JOYSTICK connector are HCMOS compatible switching levels low 1 00V high 3 25V Previously they were documented as TTL compatible low 0 4V high 2...

Страница 5: ...Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com...

Страница 6: ...es 36 Proportional Feedback Control SGP 36 Integral Feedback Control SGI 37 Velocity Feedback Control SGV 37 Velocity Feedforward Control SGVF 38 Acceleration Feedforward Control SGAF 38 Gain Sets 38...

Страница 7: ...Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com...

Страница 8: ...s table Installing the AT6n50 PC card Mounting the AT6n50 AUX board Connecting all electrical components includes specifications Testing the installation Tuning the AT6n50 refer to Servo Tuner User Gu...

Страница 9: ...under all potential conditions Failure to do so can result in damage to equipment and or serious injury to personnel Always remove power to the computer before Installing or removing the AT6n50 PC ca...

Страница 10: ...ransitions 625 ns Analog joystick connector Voltage range 0 2 5VDC 8 bit A D converter Input voltage must not exceed 5V 24 General Purpose Programmable HCMOS compatible with internal 6 8 KW pull ups t...

Страница 11: ...Prototype Card 800 815 320 32F Hard Disk XT 888 895 378 37F Parallel Printer 896 911 380 38F SDLC 928 943 3A0 3AF SDLC 944 955 3B0 3BB Monochrome Card 956 959 3BC 3BF Parallel Printer 960 975 3C0 3CF...

Страница 12: ...ot near the front of the computer Ease both ends of the card simultaneously down into the computer until the card s edge connector reaches the computer s mating connector see drawing below Adjust the...

Страница 13: ...ome in contact with the AT6n50 or its cables Temperature Operate the AT6n50 AUX board in ambient temperatures between 32 F 0 C and 122 F 50 C Provide a minimum of 6 inches 152 4 mm of unrestricted air...

Страница 14: ...I card only OPT AT6N50 A Removable Screw Terminal Connector Computer Chassis See page 5 for instructions on installing the ANI card in your computer ANI Connections Power LED Analog Input 1 Analog Inp...

Страница 15: ...ANA is NOT affected by the ENBL switch AUX Connector Motor Drivers WARNING REMOVE AC POWER FIRST before connecting or disconnecting the drives CONNECTIONS INTERNAL SCHEMATICS Drive Motor Internal Sch...

Страница 16: ...5A 3W Shutdown active DRIVE this output is disconnected from COM see schematic above Shutdown inactive DRIVE1111 this output is internally connected to COM see schematic above DFT IN Drive fault input...

Страница 17: ...43 Z pin 44 VIN pin 49 AGND pin 50 AT6n50 A A SHTNO 5V B B Z Z CMD AGND NOTE Dynaserv A connected to AT6n50 s A Dynaserv A connected to AT6n50 s A AT6n50 GND connected to AT6n50 COM Linearserv Drive...

Страница 18: ...D CMD DRIVE 1 ENCODER 1 SHLD GND Z Z B B A A 5V SV Drive AT6n50 X13 X8 1 500 1 16 8 15 9 X10 1 16 External 24V Power Supply Short these two terminals Connect SV A called A to AT6n50 A Connect SV A cal...

Страница 19: ...ontroller waits for the home switch to close indicating that the load has reached the home reference position The active level default is active low can be changed with the HOMLVL command You can also...

Страница 20: ...Shield Internally connected to chassis ground earth Isolated logic ground Z Channel quadrature signal input Z Channel quadrature signal input B Channel quadrature signal input B Channel quadrature sig...

Страница 21: ...Description 1 IN Analog Channel 1 Analog input for joystick control of axis Voltage range is 0 2 5VDC 8 bit A D converter CAUTION Input voltage must not exceed 5VDC 2 IN Analog Channel 2 same descript...

Страница 22: ...ble to sink at least 1mA of current AT6n50 6 8 KW 47 5 KW 74HCTxx 5VDC GND Connection to a Sourcing Output Device TRG A GND TRG B GND TRG C GND TRG D GND SHLD 1 Electronic Device Out 5 24 Volts Output...

Страница 23: ...is active low but can be changed to active high with the INLVL command Outputs Pin Function Pin Function Internal Schematic Specifications 1 2 49 50 P R O G R A M M A B L E O U T P U T S 49 5 VDC 23...

Страница 24: ...PROGRAMMING TIP Connecting to a sinking output Set the input s active level to low with the INLVL command active low Connecting to a sourcing output Set the input s active level to high with the INLV...

Страница 25: ...pen collector Sourcing Input Sinking Input Connection to an Inductive Load active low Output Connection OUT P 5V GND AT6n50 7406 4 7 KW 5VDC ISO GND External Supply up to 24VDC open collector Use an e...

Страница 26: ...le Output 1 Programmable Output 2 Programmable Output 3 1 2 3 4 5 6 7 8 5 GND I5 I4 I3 I2 I1 O5 O4 O3 O2 O1 TM8 Thumbwheel Module Connection to your own Thumbwheel Module Sign Bit Thumbwheel 1 Thumbwh...

Страница 27: ...connectors AUX 5V GND 5V OUT P IN P GND ANA ENBL GND External 5VDC Power Supply 5VDC Ground 1 AC Input AUX Boards 1 Remove the cover on the EIA plug 2 Build your power cable as shown DO NOT USE A 120V...

Страница 28: ...or message if it cannot find the card or if the download operation is not successful refer the Downloading Error table on page 31 RED Receiving power from AT bus OFF No power ANI Option Card Only Gree...

Страница 29: ...or 6 Download the operating system by clicking on the Transfers pull down menu and selecting Send Operating System After the operating system is downloaded the terminal window will display a startup m...

Страница 30: ...ay of the voltage level at the ANI inputs from the connector on the ANI option card Press the return key to move the display to the next line and save the current value 2 Change the voltage output fro...

Страница 31: ...portional gain in the PIV F servo algorithm SGI Sets the integral gain in the PIV F servo algorithm SGV Sets the velocity gain in the PIV F servo algorithm SGAF Sets the acceleration feedforward gain...

Страница 32: ...ns etc Program editor Create blocks or lines of 6000 controller code or copy portions of code from previous files You can save program editor files for later use in BASIC C etc or in the terminal emul...

Страница 33: ...Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com...

Страница 34: ...cing electrical noise Diagnostic LEDs Test options Technical support Solutions to common problems Corrective actions in response to operating system download errors Product return procedure Artisan Te...

Страница 35: ...ives are shut down possible causes are Shutdown was commanded with the DRIVE command Drive fault input DFT is active Enable input ENBL is not grounded Maximum allowable position error set with the SMP...

Страница 36: ...x ERES2000 SMxxxxE xxxx ERES4000 OEM Series motors servo OEM2300E05A MO ERES2000 OEM2303E05A MO ERES2000 OEM3400E05A MO ERES2000 OEM3401E10A MO ERES2000 OEM2300E05A MO ERES4000 OEM2303E10A MO ERES4000...

Страница 37: ...d mis wired connections Runaway if encoder counts positive when turned clockwise 1 Direction connections reversed 2 Improper tuning 1 Switch CMD with the CMD connection to drive 2 Retune the AT6n50 an...

Страница 38: ...network adapters bus mouse etc at the same address Try changing the card address see page 4 13 Waiting for Data Ready The card did not respond when expected Verify that you are downloading to the cor...

Страница 39: ...e Did any other items fail at the same time What was happening when the unit failed e g installing the unit cycling power starting other equipment etc How was the product configured in detail Which if...

Страница 40: ...ilable To effectively tune the AT6n50 and any velocity drives you may be using use the interactive tuning features in the Servo Tuner It greatly improves your efficiency and gives you powerful graphic...

Страница 41: ...position error changes such that the control algorithm would calculate a control signal less than the limit This phenomenon of reaching the output limit is called controller output saturation When sat...

Страница 42: ...what this user guide describes in the following sections Position Response Types The following table lists describes and illustrates the six basic types of position responses The primary difference a...

Страница 43: ...e AT6n50 employs a PIV F servo control algorithm The control techniques available in this system are P Proportional Feedback control with SGP command I Integral Feedback control with SGI command V Vel...

Страница 44: ...After windup occurs it will take a while before the integrator output returns to a level within the limit of the controller s output Such a delay causes excessive position overshoot and oscillation Th...

Страница 45: ...irected by the Servo Gain Acceleration Feedforward SGAF setting which is in turn multiplied by the acceleration of the commanded position to produce the control signal Consequently because the control...

Страница 46: ...se to zero If an offset exists ignore it for now it will be taken care of later in step 8 Step 3 If your system has mechanical stops manually move the load to a position mid way between them Step 4 En...

Страница 47: ...ning Setup Procedure you must tune one axis at a time Step 1 Tune the drive to output the desired velocity at a given voltage from the AT6n50 a If your system has mechanical stops manually move the lo...

Страница 48: ...easing the SSFR value provides a smoother profile but makes the servo system less stable and slower to respond SELECTING THE SSFR VALUE Refer to the SSFR command description in the 6000 Series Softwar...

Страница 49: ...he Integral Feedback Gain SGI to reduce steady state error Steady state position error is described earlier in the Performance Measurements section on page 35 a Determine the steady state position err...

Страница 50: ...oduct of SGP SGV if SGV zero set SGVF equal to SGP b Check the position error at constant velocity by issuing the TPER command c Increase SGVF to reduce the position error repeat steps a and b as nece...

Страница 51: ...amp out the oscillation SGP 15 Step 3 With SGV equal to 2 the response turns out fairly well damped see plot At this point the SGP should be raised again until oscillation or excessive overshoot appea...

Страница 52: ...all axes subsequent scaling gains servo offset PSET and SMPER commands are specific to encoder feedback ERES4000 Set encoder resolution to 4 000 counts rev all axes SCLA4000 Set scaling for programmi...

Страница 53: ...Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com...

Страница 54: ...ations guide i turn off before installing cards 5 conduit 2 21 configuration DIP switches address interrupts transfer mode 4 connections ANA analog output 8 analog channel inputs 14 ANI analog input 7...

Страница 55: ...ANA 8 drive 8 general purpose programmable connections and specs 16 problems 30 testing 23 OUT A through OUT D 16 testing 23 over damped servo response 35 overshoot 35 37 P Q panel layout 6 spacing m...

Страница 56: ...e 41 T technical assistance see inside of front cover and HELP command temperature range 3 terminal emulation set up 22 test system installation 22 test panel Motion Architect 28 thumbwheel connection...

Страница 57: ...Artisan Technology Group Quality Instrumentation Guaranteed 888 88 SOURCE www artisantg com...

Страница 58: ...nalog input 14 bit ADC ENBL DFT CW CCW HOM or Joystick digital inputs pins 15 19 6 8 K 74HCxx 47 5 K 5VDC Specs HCMOS compatible voltage range 0 24VDC Trigger Inputs pg 15 TRG n inputs 6 8 K 74HCTxx 4...

Страница 59: ...uipment Have surplus equipment taking up shelf space We ll give it a new home Learn more Visit us at artisantg com for more info on price quotes drivers technical specifications manuals and documentat...

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