Hi.
Recently, I'm dealing with a robot arm with two joints(one for shoulder and another for elbow). These two joints are in force/torque mode. At first, the arm is straight.
I want to control these joints to be at their respective position at the particular moment. It should throw a ball at that moment. Is there any way to solve this problem?
ps. I tried two solve it by making two joints start to move at different times. But there was an error(about 6 degree) between input position and actual position.
how to position control two joint
Re: how to position control two joint
Hello,
I would first try to use the two joints in position control, going from an initial position A to a final position B. For the whole movement, the joints will simply accelerate with the specific torque (unless the upper velocity limit is reached). Influencing the trajectory while in the throwing movement is difficult, because you cannot simply apply joint positions from a value table, since you won't obtain a smooth movement of correct following of the desired trajectory (small load, and the joints will kind of pause at the trajectory points, large load, and the trajectory will not be accurately followed).
The other option is to use the two joints in force/torque mode, and adjust the torques and target velocities (e.g. based on the load on the joints).
Cheers
I would first try to use the two joints in position control, going from an initial position A to a final position B. For the whole movement, the joints will simply accelerate with the specific torque (unless the upper velocity limit is reached). Influencing the trajectory while in the throwing movement is difficult, because you cannot simply apply joint positions from a value table, since you won't obtain a smooth movement of correct following of the desired trajectory (small load, and the joints will kind of pause at the trajectory points, large load, and the trajectory will not be accurately followed).
The other option is to use the two joints in force/torque mode, and adjust the torques and target velocities (e.g. based on the load on the joints).
Cheers