Stall Protection
Stall Protection
Hello,
I am developing linear actuator which has approximately 1 kg of load on motor constantly. I am using 2x7A model and it works good in no load condition.In full load condition what happened is motor was not able to move in position control mode and current was constantly supplied which was 3 Amps(equal to stall current of motor) after which probably my motor damaged. Is there any kind of stall protection on motor controller which will cut down PWM once it detects motor is not able to move because of load or lack of power supplied to it? I read posts about adding deadzone QPPS counts but I am not clear how will it work and solve my issue of not damaging motor by cutting down power ? Sorry but I didnt get any documentation for deadzone also.Please help me solving this problem.
I am developing linear actuator which has approximately 1 kg of load on motor constantly. I am using 2x7A model and it works good in no load condition.In full load condition what happened is motor was not able to move in position control mode and current was constantly supplied which was 3 Amps(equal to stall current of motor) after which probably my motor damaged. Is there any kind of stall protection on motor controller which will cut down PWM once it detects motor is not able to move because of load or lack of power supplied to it? I read posts about adding deadzone QPPS counts but I am not clear how will it work and solve my issue of not damaging motor by cutting down power ? Sorry but I didnt get any documentation for deadzone also.Please help me solving this problem.
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Basicmicro Support
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- Joined: Thu Feb 26, 2015 9:45 pm
Re: Stall Protection
No, there is no stall protection in the Roboclaw(not a timeout at X amps shutdown). You can set the maximum current allowed but this is an always on system. Eg If you set it to 3amps it will let you pull 3amps indefinitely. If you set it to 1amp it will let you pull 1amp indefinetly.
Note that On larger roboclaws the current sense resolution is not accurate enough for very low amp limits(eg 3amps is about the lowest you could set on a 2x15 or 2x30. The 2x7A has 10times the resolution on current readings so it can be set pretty accurately down to 1amp or even lower.
I think you are talking about the off deadzone. This lets you set what is considered the zero or the target position. For example if you tell the controller to move the motor to 1000 and it only reaches 995 with a deadzone of 5 it would consider it has reached the target position and stop powering the motor(until something external pushes the motor out of the deadzone).
This wont prevent all stall current situations though. Only if the stall would have happened with in the deadzone. If for example something blocked the motor movement well before it reach the deadzone of the target position it would stay stalled.
Note that On larger roboclaws the current sense resolution is not accurate enough for very low amp limits(eg 3amps is about the lowest you could set on a 2x15 or 2x30. The 2x7A has 10times the resolution on current readings so it can be set pretty accurately down to 1amp or even lower.
I think you are talking about the off deadzone. This lets you set what is considered the zero or the target position. For example if you tell the controller to move the motor to 1000 and it only reaches 995 with a deadzone of 5 it would consider it has reached the target position and stop powering the motor(until something external pushes the motor out of the deadzone).
This wont prevent all stall current situations though. Only if the stall would have happened with in the deadzone. If for example something blocked the motor movement well before it reach the deadzone of the target position it would stay stalled.