Mastering the BEAR Actuator 05: PID Tuning & Control Hierarchy

In this talk

1. 0:46

   Stabilize the current loop first

   Velocity, position, and direct force modes all depend on the underlying IQ and ID current loops. The presenter recommends keeping the factory current-loop gains and says the current-loop D gain should stay at zero; IQ and ID PID settings should match in torque mode.

2. 1:48

   Tune velocity tracking

   Velocity mode adds a loop above current control. Suggested starting values are P between 0.5 and 1, with I and D at zero. Increase P while comparing actual and target velocity, and add a small I value, typically 0 to 0.01, if gear friction leaves a steady tracking offset.

3. 2:52

   Build the position cascade

   Position mode nests position, velocity, and current loops. Begin with a low position P and zero I and D, then raise P to improve speed and holding stiffness. If the joint overshoots, increase velocity P or add position D; if it sags under load, check whether the I max limit is restricting available torque.

4. 4:57

   Tune direct force as a spring and damper

   Direct force mode uses position, velocity, and IQ trajectory data. Position error sets the virtual spring response through P, velocity sets damping through D, and goal torque supplies feedforward. Start with D at about one tenth of P and keep I at zero to avoid accumulated error and oscillation.