Tuning position controller - Revision history

Tero K: edit text after param template

2015-08-28T22:07:27Z

edit text after param template

Tero K: /* Preparations */

2015-08-28T20:15:17Z

‎Preparations

Tero K: Text replacement - "\[\[([A-Z]{2,3})\]\]" to "{{param|$1}}"

2015-08-28T19:55:22Z

Text replacement - "\[\[([A-Z]{2,3})\]\]" to "{{param|$1}}"

Show changes

Tero K at 09:51, 29 June 2015

2015-06-29T09:51:45Z

Tero K at 22:37, 15 April 2014

2014-04-15T22:37:50Z

Tero K: /* Steps to do after tuning finished */

2013-09-01T13:51:57Z

‎Steps to do after tuning finished

Tero K: /* Curing tracking error and overshoot */

2013-08-28T21:18:03Z

‎Curing tracking error and overshoot

Tero K: /* Curing tracking error and overshoot */

2013-08-28T21:17:02Z

‎Curing tracking error and overshoot

Tero K at 21:15, 28 August 2013

2013-08-28T21:15:46Z

Tero K: /* Preparations */

2013-08-28T21:03:42Z

‎Preparations

@@ Line 14: / Line 14: @@
 **Choose ''Serial only'' setpoint input {{param|CM}}
 **Make other necessary adjustments to have drive powered and enabled
-**Untick Setpoint smoothing {{param|CIS}}
+**Untick {{param|CIS}}
 **Set Goals tab {{param|DIV}} and {{param|MUL}} to 50
-**Set acceleration {{param|CAL}} & velocity {{param|CVL}} limits reasonably to the levels that motor is expected to handle
+**Set {{param|CAL}} & {{param|CVL}} limits reasonably to the levels that motor is expected to handle
 *Set-up the test stimulus and capture settings from Testing tab (an example, may be varied):
 **Set target setpoint 1 [[TSP1]] to 100
@@ Line 22: / Line 22: @@
 **Set target setpoint 2 [[TSP2]] to -100
 **Set delay1 [[TSD2]] to 0.25 s
-**Choose sample rate {{param|TSR}} of 500 to 2500 Hz
+**Choose {{param|TSR}} of 500 to 2500 Hz
 **Choose ''Capture setpoint change in positive direction'' from the dropdown
 **''Tick Continuously repeating capture''
 **Tick ''Position setpoint'' and ''Position achieved'' from signals
 **Tick ''Start capture'' to begin continous capture.
-**Tick Enable test stimulus {{param|TSE}} to begin a continuous position back and forth motion generation
+**Tick {{param|TSE}} to begin a continuous position back and forth motion generation
 Once the steps above are done, motor should be generating short distance back and forth motion motion and position response graphs should appear on the right side of Granity about once in 3-5 seconds.
@@ Line 67: / Line 67: @@
 [[File:posgains7.png|800px|]]
-Finally after playing little bit with all of {{param|KVP}}, {{param|KVI}} and {{param|KPP}} gains experimentally, we find a less overshooting response without losing much stiffness.
+Finally after playing little bit with all of {{param|KVP}}, {{param|KVI}} and {{param|KPP}} experimentally, we find a less overshooting response without losing much stiffness.
 ===Curing tracking error and overshoot===
@@ Line 74: / Line 74: @@
 [[File:posgains8.png|800px|]]
-Reducing acceleration {{param|CAL}} and/or velocity {{param|CVL}} limits makes the trajectory easier to follow and reduces tracking error and overshooting.
+Reducing {{param|CAL}} and/or {{param|CVL}} limits makes the trajectory easier to follow and reduces tracking error and overshooting.
 [[File:posgains9.png|800px|]]
-The same may be also achieved by utilizing [[Feed-forward]] gains {{param|VFF}} and {{param|AFF}} which essentially compensate system friction and mass limiting the dynamic performance.
+The same may be also achieved by utilizing [[Feed-forward]] {{param|VFF}} and {{param|AFF}} which essentially compensate system friction and mass limiting the dynamic performance.
-The recommended way to tune FF gains, is to start increasing velocity feed-forward {{param|VFF}} until the optimum level has been found. After that, increase acceleration feed-forward {{param|AFF}} until the optimum point has been reached.
+The recommended way to tune FF gains, is to start increasing {{param|VFF}} until the optimum level has been found. After that, increase {{param|AFF}} until the optimum point has been reached.
 [[File:Poscurrentsaturation.png|800px]]
@@ Line 86: / Line 86: @@
 If following the tuning procedure does not result in satisfactory tracking performance, the problem may be asking too much from the motor. In the example above the acceleration limit is set too high to be accelerated with the given motor torque limits (or current limits).
-To verify if the problem happens due to torque limit, tick also Torque achieved and Torque setpoint signals from the Testing tab settings. In such way also motor currents will be displayed simultaneously with the position response curves. If the torque curve is limited to the set peak current limit {{param|MMC}}, then the problem is insufficient torque. In the image above we can see that the torque curves are saturated at 4A and -4A levels which matches the configured {{param|MMC}} value of 4A in this demonstration.
+To verify if the problem happens due to torque limit, tick also Torque achieved and Torque setpoint signals from the Testing tab settings. In such way also motor currents will be displayed simultaneously with the position response curves. If the torque curve is limited to the set, {{param|MMC}}, then the problem is insufficient torque. In the image above we can see that the torque curves are saturated at 4A and -4A levels which matches the configured {{param|MMC}} value of 4A in this demonstration.
 To help this, try:
-*Increasing current limits {{param|MMC}} and {{param|MCC}} if possible
+*Increasing {{param|MMC}} and {{param|MCC}} if possible
-*Reducing acceleration {{param|CAL}} and/or velocity {{param|CVL}} limits
+*Reducing {{param|CAL}} and/or {{param|CVL}} limits
 ===Steps to do after tuning finished===
 *Stop test stimulus by unticking {{param|TSE}}
-*Stop scope catpure by unticking ''Continuously repeating capture''
+*Stop scope capture by unticking ''Continuously repeating capture''
 *Undo all temporary changes made to settings
 *Save settings to drive memory by clicking ''Save settings on drive non-volatile memory'' button
@@ Line 100: / Line 100: @@
 *If setpoint signal scaling is needed, adjust {{param|MUL}} and {{param|DIV}} values. See [[Signal path of motor drive]] for explanation of velocity setpoint scale.
-{{tip|If drive will be controlled by an external motion [[controller]] with acceleration & velocity limits, such as CNC controller programs like [[Mach3]] or [[LinuxCNC]], then its recommended to increase acceleration limit {{param|CAL}} to the maximum value of 32767 and disable setpoint smoothing {{param|CIS}} to prevent drive's internal acceleration limiter modifying the [[setpoint signal]]. Using these settings effectively disables the internal acceleration limit and let's external controller to control accelerations.}}
+{{tip|If drive will be controlled by an external motion [[controller]] with acceleration & velocity limits, such as CNC controller programs like [[Mach3]] or [[LinuxCNC]], then its recommended to increase {{param|CAL}} to the maximum value of 32767 and disable {{param|CIS}} to prevent drive's internal acceleration limiter modifying the [[setpoint signal]]. Using these settings effectively disables the internal acceleration limit and let's external controller to control accelerations.}}
 [[Category:Tuning_guide]]
 [[Category:Granity_user_guide]]

@@ Line 21: / Line 21: @@
 **Set delay 1 [[TSD1]] to 0.25 seconds
 **Set target setpoint 2 [[TSP2]] to -100
-**Set delay1 [[STD2]] to 0.25 s
+**Set delay1 [[TSD2]] to 0.25 s
 **Choose sample rate {{param|TSR}} of 500 to 2500 Hz
 **Choose ''Capture setpoint change in positive direction'' from the dropdown

@@ Line 1: / Line 1: @@
-Position controller tuning means finding the correct drive settings and feedback gain values to achieve a proper [[Servo stiffness]] and response to a position [[Setpoint signal|setpoint]] change.
+{{parent|Servo motor tuning guide}}Position controller tuning means finding the correct drive settings and feedback gain values to achieve a proper [[Servo stiffness]] and response to a position [[Setpoint signal|setpoint]] change.
 ==Position control tuning method==
@@ Line 102: / Line 102: @@
 {{tip|If drive will be controlled by an external motion [[controller]] with acceleration & velocity limits, such as CNC controller programs like [[Mach3]] or [[LinuxCNC]], then its recommended to increase acceleration limit [[CAL]] to the maximum value of 32767 and disable setpoint smoothing [[CIS]] to prevent drive's internal acceleration limiter modifying the [[setpoint signal]]. Using these settings effectively disables the internal acceleration limit and let's external controller to control accelerations.}}
-[[category:Granity user guide]]
+[[Category:Tuning_guide]]
-[[category:Tuning guide]]
+[[Category:Granity_user_guide]]

@@ Line 98: / Line 98: @@
 *Save settings to drive memory by clicking ''Save settings on drive non-volatile memory'' button
 *Set preferred setpoint source [[CRI]], also consider the use of [[CIS]]
-*If setpoint signal scaling is needed, adjust [[MUL]] and [[DIV]] values
+*If setpoint signal scaling is needed, adjust [[MUL]] and [[DIV]] values. See [[Signal path of motor drive]] for explanation of velocity setpoint scale.
 {{tip|If drive will be controlled by an external motion [[controller]] with acceleration & velocity limits, such as CNC controller programs like [[Mach3]] or [[LinuxCNC]], then its recommended to increase acceleration limit [[CAL]] to the maximum value of 32767 and disable setpoint smoothing [[CIS]] to prevent drive's internal acceleration limiter modifying the [[setpoint signal]]. Using these settings effectively disables the internal acceleration limit and let's external controller to control accelerations.}}

@@ Line 100: / Line 100: @@
 *If setpoint signal scaling is needed, adjust [[MUL]] and [[DIV]] values
-{{tip|If drive will be controlled by an external motion [[controller]] with acceleration & velocity limits, such as CNC controller programs like '''Mach3''' or '''EMC2''', then its recommended to increase acceleration limit [[CAL]] to the maximum value of 32767 and disable setpoint smoothing [[CIS]] to prevent drive's internal acceleration limiter modifying the [[setpoint signal]]. Using these settings effectively disables the internal acceleration limit and let's external controller to control accelerations.}}
+{{tip|If drive will be controlled by an external motion [[controller]] with acceleration & velocity limits, such as CNC controller programs like [[Mach3]] or [[LinuxCNC]], then its recommended to increase acceleration limit [[CAL]] to the maximum value of 32767 and disable setpoint smoothing [[CIS]] to prevent drive's internal acceleration limiter modifying the [[setpoint signal]]. Using these settings effectively disables the internal acceleration limit and let's external controller to control accelerations.}}
 [[category:Granity user guide]]
 [[category:Tuning guide]]

@@ Line 84: / Line 84: @@
 [[File:Poscurrentsaturation.png|800px]]
-If following the tuning procedure does not result in satisfactory tracking performance, the problem may be asking too much from the motor. In the example above the acceleration limit is set too high to be accelerated with the given motor torque limits (or parameterized set current limits).
+If following the tuning procedure does not result in satisfactory tracking performance, the problem may be asking too much from the motor. In the example above the acceleration limit is set too high to be accelerated with the given motor torque limits (or current limits).
 To verify if the problem happens due to torque limit, tick also Torque achieved and Torque setpoint signals from the Testing tab settings. In such way also motor currents will be displayed simultaneously with the position response curves. If the torque curve is limited to the set peak current limit [[MMC]], then the problem is insufficient torque. In the image above we can see that the torque curves are saturated at 4A and -4A limits which matches the configured [[MMC]] value of this demonstration.

← Older revision		Revision as of 21:15, 28 August 2013
Line 81:		Line 81:

	The recommended way to tune FF gains, is to start increasing velocity feed-forward [[VFF]] until the optimum level has been found. After that, increase acceleration feed-forward [[AFF]] until the optimum point has been reached.		The recommended way to tune FF gains, is to start increasing velocity feed-forward [[VFF]] until the optimum level has been found. After that, increase acceleration feed-forward [[AFF]] until the optimum point has been reached.
		+
		+	[[File:Poscurrentsaturation.png\|800px]]
		+
		+	If following the tuning procedure does not result in satisfactory tracking performance, the problem may be asking too much from the motor. In the example above the acceleration limit is set too high to be accelerated with the given motor torque limits (or parameterized set current limits).
		+
		+	To verify if the problem happens due to torque limit, tick also Torque achieved and Torque setpoint signals from the Testing tab settings. In such way also motor currents will be displayed simultaneously with the position response curves. If the torque curve is limited to the set peak current limit [[MMC]], then the problem is insufficient torque. In the image above we can see that the torque curves are saturated at 4A and -4A limits which matches the configured [[MMC]] value of this demonstration.
		+
		+	To help this, try:
		+	*Increasing current limits [[MMC]] and [[MCC]] if possible
		+	*Reducing acceleration [[CAL]] and/or velocity [[CVL]] limits

	===Steps to do after tuning finished===		===Steps to do after tuning finished===