Hello everybody,
I'm looking for a guide to understand how to build a parallelogram robot like the uarm that is present in the model folder. Currently I have a model of a parallelogram structure that works without the dynamic and with passive joints set to dependent mode. If I enable the dynamic with this configuration, the parallelogram structure fall down. Does anyone know how to deal with this robot?
Thank you.
Parallelogram Robot Dynamically enabled
Re: Parallelogram Robot Dynamically enabled
Hello,
that kind of robots is tricky, when dynamically simulated. You have at least two possibilities: you can create the robot as a serial manipulator, and close loops where they need to be closed, using a loop closure constraint. This does not always give satisfying results.
Another option (and this is how it was done in the Uarm example) is to build the robot as a serial manipulator, and close loops by using additional position control-enabled joints, that would apply target angles depending on the angular value of another joint. This is best done via a joint control callback, where you can adjust the joint's target angle in each dynamic simulation step. In the uarm robot model, this happens with joints uarm_auxMotor1 and uarm_auxMotor2
Cheers
that kind of robots is tricky, when dynamically simulated. You have at least two possibilities: you can create the robot as a serial manipulator, and close loops where they need to be closed, using a loop closure constraint. This does not always give satisfying results.
Another option (and this is how it was done in the Uarm example) is to build the robot as a serial manipulator, and close loops by using additional position control-enabled joints, that would apply target angles depending on the angular value of another joint. This is best done via a joint control callback, where you can adjust the joint's target angle in each dynamic simulation step. In the uarm robot model, this happens with joints uarm_auxMotor1 and uarm_auxMotor2
Cheers