Question about the update in Lagrangian PID update

[bigscientist]

In PIDLagrangian.py, the script to get "D" is pid_d = max(0.0, self._cost_d - self._cost_ds[0]),
I wonder that "D" is the difference between neighbour value of Lagrangian and it shall be
pid_d = max(0.0, self._cost_d - self._cost_ds[-1])

[Gaiejj]

Very careful observation! In fact, this code is not written incorrectly. It was initially designed to use the first item in the _cost_ds queue to solve the pid_d. In our experiments, we found that adding this delay mechanism makes the algorithm update more smoothly. You can cancel this delay by setting the pid_d_delay parameter to 1 in omnisafe/configs/on-policy/CPPOPID.yaml.

[bigscientist]

Thank you, I get it