Detailed Description

PID regulator that takes default input SetPoint and feedback Y to produce control output.

A Proportional–Integral–Derivative (PID) regulator.

This CDP operator can be used for regulation of process control variables. An error is calculated based on setpoint default input and system feedback (parameter Y), and correction value for controller is calculated by using the P, I and D tuning parameters of the regulator.

The P (proportional) term is negatively multiplied with the error and added to the current output, so as to reduce positional errors. The I (integral) term of the regulator is multiplied by the average error and added to the output. This will attempt to reduce steady-state errors. Finally, the D (derivative) is multiplied by the rate-of-change of the error with respect to time, so as to react quicker to f.i. acceleration changes.

Arguments

PIDRegulator can be used in systems like robotic arm controller etc, where PIDRegulator output will control movement motor.

Anti-windup effect can be achieved by using controlled system actuator saturation level (f.e. robotic arm movement current speed vs max speed) giving PIDRegulator feedback about situations when system state change limit is achieved (can not be moved even faster), so that PIDRegulator does not over-calculate its output.

Read-only properties

When operator is used inside a signal its default input is automatically tied to signal's InternalValue or previous operator's output. Its default output is automatically tied to next operator's input or to signal's Value. See also CDP Operator Usage In CDP Signals.

Example

Below is an example plot of PIDRegulator system feedback (Y) signal (orange) at the time when input (SetPoint) (cyan) was set from value 0.0 to 1.0:

Actual Processing Code of the PIDRegulator

unsigned int PIDRegulator<T>::Process()
{
  if (d->reset)
  {
    d->pidCalculator.Reset();
    d->reset = false;
  }

  if (d->TDecay() >= d->Ts() && d->TDecay() == 0.0)
    return STATUS_SIGNAL_FAULT;

  m_output = d->pidCalculator.CalculateControlValue((T)m_input, d->Y(), false, d->Ts());
  d->intP = d->pidCalculator.GetIntP();
  d->intI = d->pidCalculator.GetIntI();
  d->intD = d->pidCalculator.GetIntD();

  return STATUS_OK;
}