Hello,
I am trying to use the Maestro mini with a servo for a gripper. I have 2 positions for the gripper (open and closed). But when I pick up an object in the gripper, the servo can not reach its final closed position (the object is in the way) and starts jittering. I then have to restart the controller. Is there a way to get around this? Any help would be appreciated. Thank you!
Hello.
Could you clarify why you need to restart the controller? For example, what happens if you try to just open the gripper again? Does the servo stop responding after it gets into a jittering state?
When you try to close the gripper and the object is in the way, you are essentially stalling the servo’s motor. This causes a lot of stress both electrically and mechanically on the servo. If you do not need to grip the item that hard, you might try not closing the gripper as tightly. If it still has problems, it could either be a power issue (i.e. when the servo is stalled, it draws more current than the power supply can handle and the voltage drops) or you might need a more powerful servo.
Brandon
Yes, if I just open the gripper, the servo doesn’t respond and keeps jittering. So I have to restart the controller.
I don’t have a way to know the size of the object being gripped. The objects are of varying size. So I am right now just closing the gripper completely and trying to see if there is a way to just have the servo stop when there is resistance, but I am not sure if that is possible.
To detect if the servo is encountering resistance, you will need some kind of feedback. Standard servos do not provide any feedback information back to the controller, but since current and torque are proportional, one solution might be to add a current sensor to detect when the servo is starting to encounter resistance.
Another option could be to use a specialty servo, such as one of our FEETECH servos with feedback, which provide access to the servo’s feedback potentiometer through a fourth wire. This would allow you to compare the servo’s actual position to the expected position to determine if it is getting blocked.
Alternatively, you could try adding your own separate sensor, such as a force-sensing resistor or piezoelectric sensor.
Brandon