Mobile robot stand still on sloping floor ?
Posted: Mon May 14, 2018 7:51 am
Hi,
I'm working with a 2x30A RoboClaw controller to drive two motors on a differential drive mobile robot.
I use packetSerial through TTLserial to send commands and read parameters.
The motors are controlled with velocity commands, thanks to a remote controller.
I am trying to tune the velocity PID coefficients and observed this behavior :
when controlling the robot on a sloping floor, I am able to go up the slope, but when I stop the robot (velocity commands to 0) then it slowly move down the slope. I expected the PID to maintain the position.
I tried to change the coefficients with slightly increased P coef (at some point the motors start vibrating, so I reduced at about 1000 for P), tried to increased also I, this as little impact on this behavior.
I consider switching to position control when the robot is near immobile, but I have read a post saying that mixing position and velocity control was not a good Idea.
Could this be due to a bad setting of velocity PID coefficients ?
Have you any advice to help achieve the stand still on a sloping floor ?
Thanks.
I'm working with a 2x30A RoboClaw controller to drive two motors on a differential drive mobile robot.
I use packetSerial through TTLserial to send commands and read parameters.
The motors are controlled with velocity commands, thanks to a remote controller.
I am trying to tune the velocity PID coefficients and observed this behavior :
when controlling the robot on a sloping floor, I am able to go up the slope, but when I stop the robot (velocity commands to 0) then it slowly move down the slope. I expected the PID to maintain the position.
I tried to change the coefficients with slightly increased P coef (at some point the motors start vibrating, so I reduced at about 1000 for P), tried to increased also I, this as little impact on this behavior.
I consider switching to position control when the robot is near immobile, but I have read a post saying that mixing position and velocity control was not a good Idea.
Could this be due to a bad setting of velocity PID coefficients ?
Have you any advice to help achieve the stand still on a sloping floor ?
Thanks.