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allwpilib/wpilibc/src/main/native/include/frc/controller/ProfiledPIDController.h
2020-01-06 23:30:47 -08:00

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C++

/*----------------------------------------------------------------------------*/
/* Copyright (c) 2019-2020 FIRST. All Rights Reserved. */
/* Open Source Software - may be modified and shared by FRC teams. The code */
/* must be accompanied by the FIRST BSD license file in the root directory of */
/* the project. */
/*----------------------------------------------------------------------------*/
#pragma once
#include <algorithm>
#include <cmath>
#include <functional>
#include <limits>
#include <units/units.h>
#include "frc/controller/PIDController.h"
#include "frc/smartdashboard/Sendable.h"
#include "frc/smartdashboard/SendableBuilder.h"
#include "frc/smartdashboard/SendableHelper.h"
#include "frc/trajectory/TrapezoidProfile.h"
namespace frc {
namespace detail {
void ReportProfiledPIDController();
} // namespace detail
/**
* Implements a PID control loop whose setpoint is constrained by a trapezoid
* profile.
*/
template <class Distance>
class ProfiledPIDController
: public Sendable,
public SendableHelper<ProfiledPIDController<Distance>> {
public:
using Distance_t = units::unit_t<Distance>;
using Velocity =
units::compound_unit<Distance, units::inverse<units::seconds>>;
using Velocity_t = units::unit_t<Velocity>;
using Acceleration =
units::compound_unit<Velocity, units::inverse<units::seconds>>;
using Acceleration_t = units::unit_t<Acceleration>;
using State = typename TrapezoidProfile<Distance>::State;
using Constraints = typename TrapezoidProfile<Distance>::Constraints;
/**
* Allocates a ProfiledPIDController with the given constants for Kp, Ki, and
* Kd. Users should call reset() when they first start running the controller
* to avoid unwanted behavior.
*
* @param Kp The proportional coefficient.
* @param Ki The integral coefficient.
* @param Kd The derivative coefficient.
* @param constraints Velocity and acceleration constraints for goal.
* @param period The period between controller updates in seconds. The
* default is 20 milliseconds.
*/
ProfiledPIDController(double Kp, double Ki, double Kd,
Constraints constraints, units::second_t period = 20_ms)
: m_controller(Kp, Ki, Kd, period), m_constraints(constraints) {
detail::ReportProfiledPIDController();
}
~ProfiledPIDController() override = default;
ProfiledPIDController(const ProfiledPIDController&) = default;
ProfiledPIDController& operator=(const ProfiledPIDController&) = default;
ProfiledPIDController(ProfiledPIDController&&) = default;
ProfiledPIDController& operator=(ProfiledPIDController&&) = default;
/**
* Sets the PID Controller gain parameters.
*
* Sets the proportional, integral, and differential coefficients.
*
* @param Kp Proportional coefficient
* @param Ki Integral coefficient
* @param Kd Differential coefficient
*/
void SetPID(double Kp, double Ki, double Kd) {
m_controller.SetPID(Kp, Ki, Kd);
}
/**
* Sets the proportional coefficient of the PID controller gain.
*
* @param Kp proportional coefficient
*/
void SetP(double Kp) { m_controller.SetP(Kp); }
/**
* Sets the integral coefficient of the PID controller gain.
*
* @param Ki integral coefficient
*/
void SetI(double Ki) { m_controller.SetI(Ki); }
/**
* Sets the differential coefficient of the PID controller gain.
*
* @param Kd differential coefficient
*/
void SetD(double Kd) { m_controller.SetD(Kd); }
/**
* Gets the proportional coefficient.
*
* @return proportional coefficient
*/
double GetP() const { return m_controller.GetP(); }
/**
* Gets the integral coefficient.
*
* @return integral coefficient
*/
double GetI() const { return m_controller.GetI(); }
/**
* Gets the differential coefficient.
*
* @return differential coefficient
*/
double GetD() const { return m_controller.GetD(); }
/**
* Gets the period of this controller.
*
* @return The period of the controller.
*/
units::second_t GetPeriod() const { return m_controller.GetPeriod(); }
/**
* Sets the goal for the ProfiledPIDController.
*
* @param goal The desired unprofiled setpoint.
*/
void SetGoal(State goal) { m_goal = goal; }
/**
* Sets the goal for the ProfiledPIDController.
*
* @param goal The desired unprofiled setpoint.
*/
void SetGoal(Distance_t goal) { m_goal = {goal, Velocity_t(0)}; }
/**
* Gets the goal for the ProfiledPIDController.
*/
State GetGoal() const { return m_goal; }
/**
* Returns true if the error is within the tolerance of the error.
*
* This will return false until at least one input value has been computed.
*/
bool AtGoal() const { return AtSetpoint() && m_goal == m_setpoint; }
/**
* Set velocity and acceleration constraints for goal.
*
* @param constraints Velocity and acceleration constraints for goal.
*/
void SetConstraints(Constraints constraints) { m_constraints = constraints; }
/**
* Returns the current setpoint of the ProfiledPIDController.
*
* @return The current setpoint.
*/
State GetSetpoint() const { return m_setpoint; }
/**
* Returns true if the error is within the tolerance of the error.
*
* Currently this just reports on target as the actual value passes through
* the setpoint. Ideally it should be based on being within the tolerance for
* some period of time.
*
* This will return false until at least one input value has been computed.
*/
bool AtSetpoint() const { return m_controller.AtSetpoint(); }
/**
* Enables continuous input.
*
* Rather then using the max and min input range as constraints, it considers
* them to be the same point and automatically calculates the shortest route
* to the setpoint.
*
* @param minimumInput The minimum value expected from the input.
* @param maximumInput The maximum value expected from the input.
*/
void EnableContinuousInput(Distance_t minimumInput, Distance_t maximumInput) {
m_controller.EnableContinuousInput(minimumInput.template to<double>(),
maximumInput.template to<double>());
}
/**
* Disables continuous input.
*/
void DisableContinuousInput() { m_controller.DisableContinuousInput(); }
/**
* Sets the minimum and maximum values for the integrator.
*
* When the cap is reached, the integrator value is added to the controller
* output rather than the integrator value times the integral gain.
*
* @param minimumIntegral The minimum value of the integrator.
* @param maximumIntegral The maximum value of the integrator.
*/
void SetIntegratorRange(double minimumIntegral, double maximumIntegral) {
m_controller.SetIntegratorRange(minimumIntegral, maximumIntegral);
}
/**
* Sets the error which is considered tolerable for use with
* AtSetpoint().
*
* @param positionTolerance Position error which is tolerable.
* @param velocityTolerance Velocity error which is tolerable.
*/
void SetTolerance(
Distance_t positionTolerance,
Velocity_t velocityTolerance = std::numeric_limits<double>::infinity()) {
m_controller.SetTolerance(positionTolerance.template to<double>(),
velocityTolerance.template to<double>());
}
/**
* Returns the difference between the setpoint and the measurement.
*
* @return The error.
*/
Distance_t GetPositionError() const {
return Distance_t(m_controller.GetPositionError());
}
/**
* Returns the change in error per second.
*/
Velocity_t GetVelocityError() const {
return Velocity_t(m_controller.GetVelocityError());
}
/**
* Returns the next output of the PID controller.
*
* @param measurement The current measurement of the process variable.
*/
double Calculate(Distance_t measurement) {
frc::TrapezoidProfile<Distance> profile{m_constraints, m_goal, m_setpoint};
m_setpoint = profile.Calculate(GetPeriod());
return m_controller.Calculate(measurement.template to<double>(),
m_setpoint.position.template to<double>());
}
/**
* Returns the next output of the PID controller.
*
* @param measurement The current measurement of the process variable.
* @param goal The new goal of the controller.
*/
double Calculate(Distance_t measurement, State goal) {
SetGoal(goal);
return Calculate(measurement);
}
/**
* Returns the next output of the PID controller.
*
* @param measurement The current measurement of the process variable.
* @param goal The new goal of the controller.
*/
double Calculate(Distance_t measurement, Distance_t goal) {
SetGoal(goal);
return Calculate(measurement);
}
/**
* Returns the next output of the PID controller.
*
* @param measurement The current measurement of the process variable.
* @param goal The new goal of the controller.
* @param constraints Velocity and acceleration constraints for goal.
*/
double Calculate(
Distance_t measurement, Distance_t goal,
typename frc::TrapezoidProfile<Distance>::Constraints constraints) {
SetConstraints(constraints);
return Calculate(measurement, goal);
}
/**
* Reset the previous error and the integral term.
*
* @param measurement The current measured State of the system.
*/
void Reset(const State& measurement) {
m_controller.Reset();
m_setpoint = measurement;
}
/**
* Reset the previous error and the integral term.
*
* @param measuredPosition The current measured position of the system.
* @param measuredVelocity The current measured velocity of the system.
*/
void Reset(Distance_t measuredPosition, Velocity_t measuredVelocity) {
Reset(State{measuredPosition, measuredVelocity});
}
/**
* Reset the previous error and the integral term.
*
* @param measuredPosition The current measured position of the system. The
* velocity is assumed to be zero.
*/
void Reset(Distance_t measuredPosition) {
Reset(measuredPosition, Velocity_t(0));
}
void InitSendable(frc::SendableBuilder& builder) override {
builder.SetSmartDashboardType("ProfiledPIDController");
builder.AddDoubleProperty("p", [this] { return GetP(); },
[this](double value) { SetP(value); });
builder.AddDoubleProperty("i", [this] { return GetI(); },
[this](double value) { SetI(value); });
builder.AddDoubleProperty("d", [this] { return GetD(); },
[this](double value) { SetD(value); });
builder.AddDoubleProperty(
"goal", [this] { return GetGoal().position.template to<double>(); },
[this](double value) { SetGoal(Distance_t{value}); });
}
private:
frc2::PIDController m_controller;
typename frc::TrapezoidProfile<Distance>::State m_goal;
typename frc::TrapezoidProfile<Distance>::State m_setpoint;
typename frc::TrapezoidProfile<Distance>::Constraints m_constraints;
};
} // namespace frc