Control - Revision history

Jca at 14:10, 11 March 2025

2025-03-11T14:10:48Z

← Older revision		Revision as of 16:10, 11 March 2025
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	Back to [[regbot \| ~~Regot~~]] main page.		Back to [[regbot \| Regbot]] main page.

	The main purpose of the robot is to train control theory.		The main purpose of the robot is to train control theory.

Jca: /* Robot overview */

2025-03-11T14:09:31Z

Robot overview

← Older revision		Revision as of 16:09, 11 March 2025
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	Figure 1. Overview of software data flow. Yellow are the control blocks.		Figure 1. Overview of software data flow. Yellow are the control blocks.
	Green is hardware (motor and sensors), and light-green is calculations~~. Light blue is obtained values.~~		Green is hardware (motor and sensors), and light-green is calculations.
	~~Gray is input values~~.

	The sample time for all controllers and data values is 1ms.		The sample time for all controllers and data values is 1ms.

Jca: /* Robot overview */

2025-03-11T14:08:42Z

Robot overview

← Older revision		Revision as of 16:08, 11 March 2025
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	The figure gives the robot functionality with focus on control.		The figure gives the robot functionality with focus on control.

	[[File:blockdiagram_software.png\|700px]]		<!-- [[File:blockdiagram_software.png\|700px]] -->
			[[file:blockdiagram_dataflow_2025.png \| 700px]]

	Figure 1. Overview of software data flow. Yellow are the control blocks.		Figure 1. Overview of software data flow. Yellow are the control blocks.

Jca: /* Controller configuration */

2024-11-28T13:39:55Z

Controller configuration

← Older revision		Revision as of 15:39, 28 November 2024
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	Figure 4. This dialogue configures the wheel velocity controller - shown as a PI-Lead-controller with an output limit at (+/-) 9V and a lead term in the feedback branch. A feed-forward is active with a constant gain. All other options are disabled. The blue-framed boxes indicate a traditional PID controller with a lead in the forward (and)/or feedback branch.		Figure 4. This dialogue configures the wheel velocity controller - shown as a PI-Lead-controller with an output limit at (+/-) 9V and a lead term in the feedback branch. A feed-forward is active with a constant gain. All other options are disabled. The blue-framed boxes indicate a traditional PID controller with a lead in the forward (and)/or feedback branch.

			Feedforward is in Figure 4 set with a constant gain of 4, but a pole-zero pair could also be added.

	==== Velocity control ====		==== Velocity control ====

Jca: /* Velocity control */

2024-11-28T13:39:37Z

Velocity control

← Older revision		Revision as of 15:39, 28 November 2024
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	The integrator with an integration limit can be set.		The integrator with an integration limit can be set.

	~~Feedforward is in Figure 4 set with a constant gain of 4, but a pole-zero pair could also be added.~~

	== Calibration==		== Calibration==

Jca: /* Controller configuration */

2024-11-28T13:39:12Z

Controller configuration

← Older revision		Revision as of 15:39, 28 November 2024
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	Figure 4. This dialogue configures the wheel velocity controller - shown as a PI-Lead-controller with an output limit at (+/-) 9V and a lead term in the feedback branch. A feed-forward is active with a constant gain. All other options are disabled. The blue-framed boxes indicate a traditional PID controller with a lead in the forward (and)/or feedback branch.		Figure 4. This dialogue configures the wheel velocity controller - shown as a PI-Lead-controller with an output limit at (+/-) 9V and a lead term in the feedback branch. A feed-forward is active with a constant gain. All other options are disabled. The blue-framed boxes indicate a traditional PID controller with a lead in the forward (and)/or feedback branch.

	~~In Figure 4, the~~ control ~~is set to feed-forward only (Kp~~=~~0 and Kf~~=~~4). There is also a transfer function in the feedback path with a pole with tau_pole~~=~~0.005 adding a low-pass filter with a time constant of 5ms.~~		==== Velocity control ====

	A magnetic encoder is used to estimate the robot's velocity. The estimate suffers some delay, dependent on the motor speed. See further details here [[Regbot encoder analysis]]. ~~Assuming a~~ delay of 10 ms is typically ~~fine~~ for a velocity controller design.		Figure 4 sets the velocity control to feed-forward only (Kp=0 and Kf=4). There is also a transfer function in the feedback path with a pole with tau_pole=0.005, adding a low-pass filter with a time constant of 5ms.

			A magnetic encoder is used to estimate the robot's velocity. The estimate suffers some delay, dependent on the motor speed. See further details here [[Regbot encoder analysis]]. A delay of 10 ms is typically a good value for a velocity controller design.

	The output is here limited to +/-9V.		The output is here limited to +/-9V.
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	The integrator with an integration limit can be set.		The integrator with an integration limit can be set.

	Feedforward is in ~~figure~~ 4 set with a constant gain of 4, but a pole-zero pair could be added ~~too.~~		Feedforward is in Figure 4 set with a constant gain of 4, but a pole-zero pair could also be added.

	~~NB! As velocity measurements are rather noisy, the filter in the feedback path (Lead/Lag in feed back) could be implemented as a low-pass filter with tau_zero = 0 and tau_pole = 0.005 (recommended)~~.

	== Calibration==		== Calibration==

Jca: /* Controller configuration */

2024-11-28T13:36:25Z

Controller configuration

← Older revision		Revision as of 15:36, 28 November 2024
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	[[File:control_tab.png \| 700px]]		[[File:control_tab.png \| 700px]]

	Figure 3. All control values ~~are~~ set from this page~~, click~~ on the relevant controller and enter the relevant values in the dialogue window shown below.		Figure 3. All control values can be set from this page. Click on the relevant controller and enter the relevant values in the dialogue window shown below.

	[[File:Gui_control_dialog.png \| 500px]]		[[File:Gui_control_dialog.png \| 500px]]

	Figure 4. This dialogue configures the wheel velocity controller - shown as a PI-Lead-controller with output limit at (+/-) 9V and a lead term in the feedback branch. A feed-forward is active with a constant gain. All other options are disabled. The blue framed boxes indicate a traditional PID controller with lead in forward (and)/or ~~in the~~ feedback branch.		Figure 4. This dialogue configures the wheel velocity controller - shown as a PI-Lead-controller with an output limit at (+/-) 9V and a lead term in the feedback branch. A feed-forward is active with a constant gain. All other options are disabled. The blue-framed boxes indicate a traditional PID controller with a lead in the forward (and)/or feedback branch.

	In Figure 4, the control is set to feed-forward only (Kp=0 and Kf=4). There is also a transfer function in the feedback path with a pole with tau_pole=0.005 adding a low-pass filter with a time constant of 5ms.		In Figure 4, the control is set to feed-forward only (Kp=0 and Kf=4). There is also a transfer function in the feedback path with a pole with tau_pole=0.005 adding a low-pass filter with a time constant of 5ms.

	A magnetic encoder is used to estimate the robot's velocity. The estimate suffers some delay, dependent on the motor speed. See further details here[[Regbot encoder analysis]]. Assuming a delay of 10 ms is typically fine for a velocity controller design.		A magnetic encoder is used to estimate the robot's velocity. The estimate suffers some delay, dependent on the motor speed. See further details here [[Regbot encoder analysis]]. Assuming a delay of 10 ms is typically fine for a velocity controller design.

	The output is here limited to +/-9V.		The output is here limited to +/-9V.

Jca: /* Controller configuration */

2024-11-28T13:34:28Z

Controller configuration

← Older revision		Revision as of 15:34, 28 November 2024
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	Figure 4. This dialogue configures the wheel velocity controller - shown as a PI-Lead-controller with output limit at (+/-) 9V and a lead term in the feedback branch. A feed-forward is active with a constant gain. All other options are disabled. The blue framed boxes indicate a traditional PID controller with lead in forward (and)/or in the feedback branch.		Figure 4. This dialogue configures the wheel velocity controller - shown as a PI-Lead-controller with output limit at (+/-) 9V and a lead term in the feedback branch. A feed-forward is active with a constant gain. All other options are disabled. The blue framed boxes indicate a traditional PID controller with lead in forward (and)/or in the feedback branch.

	In ~~figure~~ 4 the control is set to feed-forward only (Kp=0 and a Kf=4)~~, there~~ is ~~further~~ a transfer function in the feedback path with a pole with tau_pole=0.005, a low pass filter with a time constant of 5ms, ~~which~~ for ~~this robot is~~ a ~~good idea the reduce the noise in the~~ velocity ~~measurements~~.		In Figure 4, the control is set to feed-forward only (Kp=0 and Kf=4). There is also a transfer function in the feedback path with a pole with tau_pole=0.005 adding a low-pass filter with a time constant of 5ms.

			A magnetic encoder is used to estimate the robot's velocity. The estimate suffers some delay, dependent on the motor speed. See further details here[[Regbot encoder analysis]]. Assuming a delay of 10 ms is typically fine for a velocity controller design.

	The output is here limited to +/-9V.		The output is here limited to +/-9V.

Jca: /* Balance point */

2023-12-07T12:03:47Z

Balance point

← Older revision		Revision as of 14:03, 7 December 2023
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	* See [[Regbot calibration]] for IMU calibration.		* See [[Regbot calibration]] for IMU calibration.

	~~=== Balance point ===~~


	~~<!-- [[File:Gui_robot.png \| 800px]] -->~~

	The IMU detects tilt, which should be zero at the balance point. Adjust the IMU board rotation around the y-axis (see Figure 5) so that the tilt angle is close to zero when the robot is held at the balance point. The board is mounted upside down, and as the center of gravity is not at the symmetry point, an angle typically around 170 degrees should be found.

	~~To change the '''IMU board''' angle; press the 'edit', change, and then 'Apply'.~~

	~~The measured tilt at the balance point should be less than 0.5 degrees.~~

	~~The balance point can also be fine-tuned in the field "'''tilt offset'''" in the '''Robot''' tab.~~

	~~To edit the "'''tilt offset'''" first press "'''edit'''", then change the value, press "'''save'''".~~

	* Remember to press "'''Save to flash'''" to use these values after a reboot.

	== Heading control feature ==		== Heading control feature ==

Jca: /* IMU */

2023-12-07T12:03:22Z

IMU

← Older revision		Revision as of 14:03, 7 December 2023
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	Figure 5. IMU data, gyro, accelerometer and tilt. The Gyro can be calibrated from here. The IMU board should be calibrated to show zero tilt, when in balance.		Figure 5. IMU data, gyro, accelerometer and tilt. The Gyro can be calibrated from here. The IMU board should be calibrated to show zero tilt, when in balance.

	* See [[Regbot ~~calibrate~~]] for IMU calibration.		* See [[Regbot calibration]] for IMU calibration.

	=== Balance point ===		=== Balance point ===