I’ve bought 4 24V12 to control my robot . Actually I control the drive trought RC PWM it works perfectly.
On the controller i’ve only set the min max of the RC PWM. When I go slowly the robot stop when it hurt a rock, I have no speed feedback to make my own regulation . Is it possible to change the control mode like RC electronic in open loop (remove the potentiometer to read position) . When I give a speed the controller make a regulation to keep this speed trought the current feedback read.
The Simple Motor Controller 24v12 does not have any built-in features for doing closed-loop speed control. I am not sure what kind of open-loop RC control you are referring to, but I do not think you will be able to get reliable speed control through current feedback; current is more of an indication of torque than speed.
If you have motors with encoders, you might be able to use a separate microcontroller (such as an Arduino board or one of our Arduino-compatible A-Star 32U4 controllers) to process the RC input and encoder feedback and adjust the target for the SMCs accordingly.
Another option for closed-loop speed control with RC input is to use one of our jrk motor controllers with one channel of a quadrature encoder:
The electronic of a servo works like a speed regulation when you remove the potentiometer that give the position.
When the electronic send a speed to the motor, it try to keep the speed even if the motor is slowed down by a friction.
The speed regulation is done by a current sensing at high speed.
Actually in my application I can’t have feedback I’ve only the 2 wire to drive the motor.
In my experience, removing the potentiometer feedback on a servo results in open-loop speed control. I do not know of any servos that do current-based closed-loop speed control. As I mentioned, the current is not a good indication of the speed since it varies linearly with torque, not speed. In any case, the Simple Motor Controller does not have any current sensing or tachometer feedback features. To get the behavior you are describing, you would need some type of closed-loop feedback.