Page 1 of 1

how can velocity and torque controls be executed simultaneously

Posted: Wed Feb 10, 2021 3:52 am
by zhuwei996
Hi, Hebi Robotics,

I am now using IGOR. When I am reading the official python code, there is one question confusing me a lot.
For the wheel actuators, velocity and torque commands are sent simultaneously.
I wonder whether these two kinds of commands confict with each other.
In my opinion, these two modes should be executed separately.
Actuators are not my research field, so I feel confused.
Thanks a lot for your attentions!

Wei ZHU

Re: how can velocity and torque controls be executed simultaneously

Posted: Wed Feb 10, 2021 9:24 am
by florian_enner
You are right that this is an unconventional way to do it. Simultaneous control of position / velocity / torque can provide additional information to the system that can improve tracking without requiring very stiff gains. The following YouTube tutorial explains the combination in more detail: https://youtu.be/9WjNo5DCtfg

For Igor there is also an impedance controller running in addition to the velocity controller to keep the wheels centered. The video https://youtu.be/7JrBDRNPxv4 talks about the development process and the impedance controller to keep the legs together (at 06:50 min).

Please let us know in case things are still unclear.