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PID stuff
02-08-2018, 09:23 PM
Post: #4
RE: PID stuff
(01-17-2018 07:12 PM)JJrobots JP Wrote:  Thanks! Keep us updated with your version of the PID control.
Regarding the dt: actually, the gyro (MPU-6050) providing a continuously updated value periodically, gives us the dt reference. It gives the equivalent of a "hardware clock"
The current version of the PID control is the result of several iterations. This one makes the B-robot behaves nicely in the static position and while moving (it is a well balanced PID control) BUT there are other versions (not published) which make the B-robot extremely stable but (as VanDijk commented) not as smooth to control when the robot wanders around. We have been looking for the best compromise between standing stability and control.

As stated above, please keep us updated with your experience! The current PID configuration does not have to be the optimum one.

Please excuse me for my long delay.
Some little things seem to improve the dynamic behavior: Anybody here in this forum had changed the frequency of the low-pass-filter for "estimated_speed_filtered", Coefficients are now 0.95/0.05. I think this and changing of the factor with "angular_velocity" from 25 to 50 had brought a small success.
The periodical update time dt is with my sketch-version not constant, because I don't use this "if (MPU6050_newData())". Disadvantage: The use of some additional "Serial.print()" e.g. change the periodical update time and the behavior of the robot. But I have the possibility to experiment with this time. My dt is only 3..4ms, with MPU6050-provided it would be 10ms?
I don't know, what is better? But the robot works rather fine, with a simple sonar by now too.
Perhaps some different control parameter settings, selectable with smartphone, would be good,
for instance for running and steering, for driving up a rising plane or for compensation a unsymmetric load. I will try it.
Thank you both once more!
Claus
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Messages In This Thread
PID stuff - scandermore - 01-12-2018, 10:40 AM
RE: PID stuff - vanDijk - 01-16-2018, 09:01 PM
RE: PID stuff - JJrobots JP - 01-17-2018, 07:12 PM
RE: PID stuff - vanDijk - 02-08-2018 09:23 PM

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