Saturation prevention blocks integral part calculation when output is below zero

[koopee]

I use PID controller with input that is quite small and quite often drops below zero. When input drops below zero, the PID integration does not work. Saturation prevents decrementing the integral value i_term when input is less than zero.

I fixed mine by setting the comparison self._last_output > -100 and self._last_output < 100

    # Calculate I and avoids Sturation
    if self._last_output is None or (
        self._last_output > 0 and self._last_output < 100
    ):
        self._i_term += self._ki * error * delta_time
        self._i_term = self.clamp_value(self._i_term, self._windup)

https://github.com/soloam/ha-pid-controller/blob/60052392bdaa114dc9296fcf7d3b58db48129993/custom_components/pid_controller/pidcontroller.py#L88C1-L90C11