Can force/torque control of joint achieve positive and negative motion during one control loop?

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biscuit122
Posts: 30
Joined: 23 Jan 2018, 16:16

Can force/torque control of joint achieve positive and negative motion during one control loop?

In this tutorial, I set a sin function to define a joint force control. But it only move in one direction, so if I do not change target velocity, do you have method to move joint in two direction during one control loop? https://github.com/feig122/force_test

coppelia
Posts: 7159
Joined: 14 Dec 2012, 00:25

Re: Can force/torque control of joint achieve positive and negative motion during one control loop?

Hello,

you can only set the amplitude of the force/torque. The sign is set via the joint target velocity. So set following:

Code: Select all

``````sim.setJointForce(handle,math.abs(f))
if f~=0 then
sim.setJointTargetVelocity(handle,math.abs(vel)*f/math.abs(f))
end``````
Cheers

biscuit122
Posts: 30
Joined: 23 Jan 2018, 16:16

Re: Can force/torque control of joint achieve positive and negative motion during one control loop?

coppelia wrote:
07 Nov 2018, 08:02
Hello,

you can only set the amplitude of the force/torque. The sign is set via the joint target velocity. So set following:

Code: Select all

``````sim.setJointForce(handle,math.abs(f))
if f~=0 then
sim.setJointTargetVelocity(handle,math.abs(vel)*f/math.abs(f))
end``````
Cheers
Thanks for your brilliant tutorial, which helps me a big deal!