PIDController

PIDController#

class do_dpc.control_utils.pid.PIDController(gains, dt, alpha=0.1)[source]#

Bases: object

A discrete-time PID controller. This class implements a discrete-time PID (Proportional-Integral-Derivative) controller. It computes the control action based on the error between the desired setpoint and the current process variable, using the PID control law:

\[u(t) = K_p e(t) + K_i \int_0^t e(\tau) d\tau + K_d \frac{d}{dt} e(t)\]
where:

  • \(u(t)\) is the control output

  • \(e(t)\) is the error between the setpoint and the process variable

  • \(K_p\), \(K_i\), and \(K_d\) are the proportional, integral, and derivative gains, respectively.

gains#

An instance of PIDGains containing the PID constants: Kp, Ki, and Kd.

Type:

PIDGains

dt#

Sampling time (time step between updates).

Type:

float

alpha#

Smoothing factor for the derivative term (low-pass filter for noise reduction).

Type:

float

integral#

The accumulated integral term.

Type:

float

prev_error#

The previous error used for the derivative calculation.

Type:

float

filtered_derivative#

The filtered derivative term.

Type:

float

Parameters:

  • gains (PIDGains) – An instance of PIDGains containing Kp, Ki, and Kd.

  • dt (float) – Sampling time.

  • alpha (float, optional) – Smoothing factor for the derivative term. Defaults to 0.1.

Raises:

ValueError – If dt is not positive.

Methods#

compute#

do_dpc.control_utils.pid.PIDController.compute(self, error)#

Computes the discrete PID control output.

Parameters:

error (float) – The error signal (difference between setpoint and measurement).

Returns:

The computed control signal.

Return type:

float

compute_with_derivative#

do_dpc.control_utils.pid.PIDController.compute_with_derivative(self, error, error_derivative)#

Computes the discrete PID control output with an externally provided error derivative.

Parameters:

  • error (float) – The error signal (difference between setpoint and measurement).

  • error_derivative (float) – The derivative of the error signal.

Returns:

The computed control signal.

Return type:

float

Contents