Squashed 'third_party/allwpilib_2017/' content from commit 35ac87d
Change-Id: I7bb6f5556c30d3f5a092e68de0be9c710c60c9f4
git-subtree-dir: third_party/allwpilib_2017
git-subtree-split: 35ac87d6ff8b7f061c4f18c9ea316e5dccd4888a
diff --git a/wpilibc/athena/src/PIDController.cpp b/wpilibc/athena/src/PIDController.cpp
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+++ b/wpilibc/athena/src/PIDController.cpp
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+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2008-2017. 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. */
+/*----------------------------------------------------------------------------*/
+
+#include "PIDController.h"
+
+#include <cmath>
+#include <vector>
+
+#include "HAL/HAL.h"
+#include "Notifier.h"
+#include "PIDOutput.h"
+#include "PIDSource.h"
+
+using namespace frc;
+
+static const std::string kP = "p";
+static const std::string kI = "i";
+static const std::string kD = "d";
+static const std::string kF = "f";
+static const std::string kSetpoint = "setpoint";
+static const std::string kEnabled = "enabled";
+
+/**
+ * Allocate a PID object with the given constants for P, I, D.
+ *
+ * @param Kp the proportional coefficient
+ * @param Ki the integral coefficient
+ * @param Kd the derivative coefficient
+ * @param source The PIDSource object that is used to get values
+ * @param output The PIDOutput object that is set to the output value
+ * @param period the loop time for doing calculations. This particularly
+ * effects calculations of the integral and differental terms.
+ * The default is 50ms.
+ */
+PIDController::PIDController(double Kp, double Ki, double Kd, PIDSource* source,
+ PIDOutput* output, double period)
+ : PIDController(Kp, Ki, Kd, 0.0, source, output, period) {}
+
+/**
+ * Allocate a PID object with the given constants for P, I, D.
+ *
+ * @param Kp the proportional coefficient
+ * @param Ki the integral coefficient
+ * @param Kd the derivative coefficient
+ * @param source The PIDSource object that is used to get values
+ * @param output The PIDOutput object that is set to the output value
+ * @param period the loop time for doing calculations. This particularly
+ * effects calculations of the integral and differental terms.
+ * The default is 50ms.
+ */
+PIDController::PIDController(double Kp, double Ki, double Kd, double Kf,
+ PIDSource* source, PIDOutput* output,
+ double period) {
+ m_controlLoop = std::make_unique<Notifier>(&PIDController::Calculate, this);
+
+ m_P = Kp;
+ m_I = Ki;
+ m_D = Kd;
+ m_F = Kf;
+
+ m_pidInput = source;
+ m_pidOutput = output;
+ m_period = period;
+
+ m_controlLoop->StartPeriodic(m_period);
+ m_setpointTimer.Start();
+
+ static int instances = 0;
+ instances++;
+ HAL_Report(HALUsageReporting::kResourceType_PIDController, instances);
+}
+
+PIDController::~PIDController() {
+ // forcefully stopping the notifier so the callback can successfully run.
+ m_controlLoop->Stop();
+ if (m_table != nullptr) m_table->RemoveTableListener(this);
+}
+
+/**
+ * Read the input, calculate the output accordingly, and write to the output.
+ * This should only be called by the Notifier.
+ */
+void PIDController::Calculate() {
+ bool enabled;
+ PIDSource* pidInput;
+ PIDOutput* pidOutput;
+
+ {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ pidInput = m_pidInput;
+ pidOutput = m_pidOutput;
+ enabled = m_enabled;
+ }
+
+ if (pidInput == nullptr) return;
+ if (pidOutput == nullptr) return;
+
+ if (enabled) {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ double input = pidInput->PIDGet();
+ double result;
+ PIDOutput* pidOutput;
+
+ m_error = GetContinuousError(m_setpoint - input);
+
+ if (m_pidInput->GetPIDSourceType() == PIDSourceType::kRate) {
+ if (m_P != 0) {
+ double potentialPGain = (m_totalError + m_error) * m_P;
+ if (potentialPGain < m_maximumOutput) {
+ if (potentialPGain > m_minimumOutput)
+ m_totalError += m_error;
+ else
+ m_totalError = m_minimumOutput / m_P;
+ } else {
+ m_totalError = m_maximumOutput / m_P;
+ }
+ }
+
+ m_result = m_D * m_error + m_P * m_totalError + CalculateFeedForward();
+ } else {
+ if (m_I != 0) {
+ double potentialIGain = (m_totalError + m_error) * m_I;
+ if (potentialIGain < m_maximumOutput) {
+ if (potentialIGain > m_minimumOutput)
+ m_totalError += m_error;
+ else
+ m_totalError = m_minimumOutput / m_I;
+ } else {
+ m_totalError = m_maximumOutput / m_I;
+ }
+ }
+
+ m_result = m_P * m_error + m_I * m_totalError +
+ m_D * (m_error - m_prevError) + CalculateFeedForward();
+ }
+ m_prevError = m_error;
+
+ if (m_result > m_maximumOutput)
+ m_result = m_maximumOutput;
+ else if (m_result < m_minimumOutput)
+ m_result = m_minimumOutput;
+
+ pidOutput = m_pidOutput;
+ result = m_result;
+
+ pidOutput->PIDWrite(result);
+
+ // Update the buffer.
+ m_buf.push(m_error);
+ m_bufTotal += m_error;
+ // Remove old elements when buffer is full.
+ if (m_buf.size() > m_bufLength) {
+ m_bufTotal -= m_buf.front();
+ m_buf.pop();
+ }
+ }
+}
+
+/**
+ * Calculate the feed forward term.
+ *
+ * Both of the provided feed forward calculations are velocity feed forwards.
+ * If a different feed forward calculation is desired, the user can override
+ * this function and provide his or her own. This function does no
+ * synchronization because the PIDController class only calls it in synchronized
+ * code, so be careful if calling it oneself.
+ *
+ * If a velocity PID controller is being used, the F term should be set to 1
+ * over the maximum setpoint for the output. If a position PID controller is
+ * being used, the F term should be set to 1 over the maximum speed for the
+ * output measured in setpoint units per this controller's update period (see
+ * the default period in this class's constructor).
+ */
+double PIDController::CalculateFeedForward() {
+ if (m_pidInput->GetPIDSourceType() == PIDSourceType::kRate) {
+ return m_F * GetSetpoint();
+ } else {
+ double temp = m_F * GetDeltaSetpoint();
+ m_prevSetpoint = m_setpoint;
+ m_setpointTimer.Reset();
+ return temp;
+ }
+}
+
+/**
+ * Set the PID Controller gain parameters.
+ *
+ * Set the proportional, integral, and differential coefficients.
+ *
+ * @param p Proportional coefficient
+ * @param i Integral coefficient
+ * @param d Differential coefficient
+ */
+void PIDController::SetPID(double p, double i, double d) {
+ {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ m_P = p;
+ m_I = i;
+ m_D = d;
+ }
+
+ if (m_table != nullptr) {
+ m_table->PutNumber("p", m_P);
+ m_table->PutNumber("i", m_I);
+ m_table->PutNumber("d", m_D);
+ }
+}
+
+/**
+ * Set the PID Controller gain parameters.
+ *
+ * Set the proportional, integral, and differential coefficients.
+ *
+ * @param p Proportional coefficient
+ * @param i Integral coefficient
+ * @param d Differential coefficient
+ * @param f Feed forward coefficient
+ */
+void PIDController::SetPID(double p, double i, double d, double f) {
+ {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ m_P = p;
+ m_I = i;
+ m_D = d;
+ m_F = f;
+ }
+
+ if (m_table != nullptr) {
+ m_table->PutNumber("p", m_P);
+ m_table->PutNumber("i", m_I);
+ m_table->PutNumber("d", m_D);
+ m_table->PutNumber("f", m_F);
+ }
+}
+
+/**
+ * Get the Proportional coefficient.
+ *
+ * @return proportional coefficient
+ */
+double PIDController::GetP() const {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ return m_P;
+}
+
+/**
+ * Get the Integral coefficient.
+ *
+ * @return integral coefficient
+ */
+double PIDController::GetI() const {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ return m_I;
+}
+
+/**
+ * Get the Differential coefficient.
+ *
+ * @return differential coefficient
+ */
+double PIDController::GetD() const {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ return m_D;
+}
+
+/**
+ * Get the Feed forward coefficient.
+ *
+ * @return Feed forward coefficient
+ */
+double PIDController::GetF() const {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ return m_F;
+}
+
+/**
+ * Return the current PID result.
+ *
+ * This is always centered on zero and constrained the the max and min outs.
+ *
+ * @return the latest calculated output
+ */
+double PIDController::Get() const {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ return m_result;
+}
+
+/**
+ * Set the PID controller to consider the input to be continuous,
+ *
+ * Rather then using the max and min in as constraints, it considers them to
+ * be the same point and automatically calculates the shortest route to
+ * the setpoint.
+ *
+ * @param continuous true turns on continuous, false turns off continuous
+ */
+void PIDController::SetContinuous(bool continuous) {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ m_continuous = continuous;
+}
+
+/**
+ * Sets the maximum and minimum values expected from the input.
+ *
+ * @param minimumInput the minimum value expected from the input
+ * @param maximumInput the maximum value expected from the output
+ */
+void PIDController::SetInputRange(double minimumInput, double maximumInput) {
+ {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ m_minimumInput = minimumInput;
+ m_maximumInput = maximumInput;
+ }
+
+ SetSetpoint(m_setpoint);
+}
+
+/**
+ * Sets the minimum and maximum values to write.
+ *
+ * @param minimumOutput the minimum value to write to the output
+ * @param maximumOutput the maximum value to write to the output
+ */
+void PIDController::SetOutputRange(double minimumOutput, double maximumOutput) {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ m_minimumOutput = minimumOutput;
+ m_maximumOutput = maximumOutput;
+}
+
+/**
+ * Set the setpoint for the PIDController.
+ *
+ * Clears the queue for GetAvgError().
+ *
+ * @param setpoint the desired setpoint
+ */
+void PIDController::SetSetpoint(double setpoint) {
+ {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+
+ if (m_maximumInput > m_minimumInput) {
+ if (setpoint > m_maximumInput)
+ m_setpoint = m_maximumInput;
+ else if (setpoint < m_minimumInput)
+ m_setpoint = m_minimumInput;
+ else
+ m_setpoint = setpoint;
+ } else {
+ m_setpoint = setpoint;
+ }
+
+ // Clear m_buf.
+ m_buf = std::queue<double>();
+ m_bufTotal = 0;
+ }
+
+ if (m_table != nullptr) {
+ m_table->PutNumber("setpoint", m_setpoint);
+ }
+}
+
+/**
+ * Returns the current setpoint of the PIDController.
+ *
+ * @return the current setpoint
+ */
+double PIDController::GetSetpoint() const {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ return m_setpoint;
+}
+
+/**
+ * Returns the change in setpoint over time of the PIDController.
+ *
+ * @return the change in setpoint over time
+ */
+double PIDController::GetDeltaSetpoint() const {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ return (m_setpoint - m_prevSetpoint) / m_setpointTimer.Get();
+}
+
+/**
+ * Returns the current difference of the input from the setpoint.
+ *
+ * @return the current error
+ */
+double PIDController::GetError() const {
+ double setpoint = GetSetpoint();
+ {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ return GetContinuousError(setpoint - m_pidInput->PIDGet());
+ }
+}
+
+/**
+ * Sets what type of input the PID controller will use.
+ */
+void PIDController::SetPIDSourceType(PIDSourceType pidSource) {
+ m_pidInput->SetPIDSourceType(pidSource);
+}
+/**
+ * Returns the type of input the PID controller is using.
+ *
+ * @return the PID controller input type
+ */
+PIDSourceType PIDController::GetPIDSourceType() const {
+ return m_pidInput->GetPIDSourceType();
+}
+
+/**
+ * Returns the current average of the error over the past few iterations.
+ *
+ * You can specify the number of iterations to average with SetToleranceBuffer()
+ * (defaults to 1). This is the same value that is used for OnTarget().
+ *
+ * @return the average error
+ */
+double PIDController::GetAvgError() const {
+ double avgError = 0;
+ {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ // Don't divide by zero.
+ if (m_buf.size()) avgError = m_bufTotal / m_buf.size();
+ }
+ return avgError;
+}
+
+/*
+ * Set the percentage error which is considered tolerable for use with
+ * OnTarget.
+ *
+ * @param percentage error which is tolerable
+ */
+void PIDController::SetTolerance(double percent) {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ m_toleranceType = kPercentTolerance;
+ m_tolerance = percent;
+}
+
+/*
+ * Set the absolute error which is considered tolerable for use with
+ * OnTarget.
+ *
+ * @param percentage error which is tolerable
+ */
+void PIDController::SetAbsoluteTolerance(double absTolerance) {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ m_toleranceType = kAbsoluteTolerance;
+ m_tolerance = absTolerance;
+}
+
+/*
+ * Set the percentage error which is considered tolerable for use with
+ * OnTarget.
+ *
+ * @param percentage error which is tolerable
+ */
+void PIDController::SetPercentTolerance(double percent) {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ m_toleranceType = kPercentTolerance;
+ m_tolerance = percent;
+}
+
+/*
+ * Set the number of previous error samples to average for tolerancing. When
+ * determining whether a mechanism is on target, the user may want to use a
+ * rolling average of previous measurements instead of a precise position or
+ * velocity. This is useful for noisy sensors which return a few erroneous
+ * measurements when the mechanism is on target. However, the mechanism will
+ * not register as on target for at least the specified bufLength cycles.
+ *
+ * @param bufLength Number of previous cycles to average. Defaults to 1.
+ */
+void PIDController::SetToleranceBuffer(int bufLength) {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ m_bufLength = bufLength;
+
+ // Cut the buffer down to size if needed.
+ while (m_buf.size() > static_cast<uint32_t>(bufLength)) {
+ m_bufTotal -= m_buf.front();
+ m_buf.pop();
+ }
+}
+
+/*
+ * Return true if the error is within the percentage of the total input range,
+ * determined by SetTolerance. This asssumes that the maximum and minimum input
+ * were set using SetInput.
+ *
+ * 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 PIDController::OnTarget() const {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ if (m_buf.size() == 0) return false;
+ double error = GetAvgError();
+ switch (m_toleranceType) {
+ case kPercentTolerance:
+ return std::fabs(error) <
+ m_tolerance / 100 * (m_maximumInput - m_minimumInput);
+ break;
+ case kAbsoluteTolerance:
+ return std::fabs(error) < m_tolerance;
+ break;
+ case kNoTolerance:
+ // TODO: this case needs an error
+ return false;
+ }
+ return false;
+}
+
+/**
+ * Begin running the PIDController.
+ */
+void PIDController::Enable() {
+ {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ m_enabled = true;
+ }
+
+ if (m_table != nullptr) {
+ m_table->PutBoolean("enabled", true);
+ }
+}
+
+/**
+ * Stop running the PIDController, this sets the output to zero before stopping.
+ */
+void PIDController::Disable() {
+ {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ m_pidOutput->PIDWrite(0);
+ m_enabled = false;
+ }
+
+ if (m_table != nullptr) {
+ m_table->PutBoolean("enabled", false);
+ }
+}
+
+/**
+ * Return true if PIDController is enabled.
+ */
+bool PIDController::IsEnabled() const {
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ return m_enabled;
+}
+
+/**
+ * Reset the previous error, the integral term, and disable the controller.
+ */
+void PIDController::Reset() {
+ Disable();
+
+ std::lock_guard<priority_recursive_mutex> sync(m_mutex);
+ m_prevError = 0;
+ m_totalError = 0;
+ m_result = 0;
+}
+
+std::string PIDController::GetSmartDashboardType() const {
+ return "PIDController";
+}
+
+void PIDController::InitTable(std::shared_ptr<ITable> subtable) {
+ if (m_table != nullptr) m_table->RemoveTableListener(this);
+ m_table = subtable;
+ if (m_table != nullptr) {
+ m_table->PutNumber(kP, GetP());
+ m_table->PutNumber(kI, GetI());
+ m_table->PutNumber(kD, GetD());
+ m_table->PutNumber(kF, GetF());
+ m_table->PutNumber(kSetpoint, GetSetpoint());
+ m_table->PutBoolean(kEnabled, IsEnabled());
+ m_table->AddTableListener(this, false);
+ }
+}
+
+/**
+ * Wraps error around for continuous inputs. The original error is returned if
+ * continuous mode is disabled. This is an unsynchronized function.
+ *
+ * @param error The current error of the PID controller.
+ * @return Error for continuous inputs.
+ */
+double PIDController::GetContinuousError(double error) const {
+ if (m_continuous) {
+ if (std::fabs(error) > (m_maximumInput - m_minimumInput) / 2) {
+ if (error > 0) {
+ return error - (m_maximumInput - m_minimumInput);
+ } else {
+ return error + (m_maximumInput - m_minimumInput);
+ }
+ }
+ }
+
+ return error;
+}
+
+std::shared_ptr<ITable> PIDController::GetTable() const { return m_table; }
+
+void PIDController::ValueChanged(ITable* source, llvm::StringRef key,
+ std::shared_ptr<nt::Value> value, bool isNew) {
+ if (key == kP || key == kI || key == kD || key == kF) {
+ if (m_P != m_table->GetNumber(kP, 0.0) ||
+ m_I != m_table->GetNumber(kI, 0.0) ||
+ m_D != m_table->GetNumber(kD, 0.0) ||
+ m_F != m_table->GetNumber(kF, 0.0)) {
+ SetPID(m_table->GetNumber(kP, 0.0), m_table->GetNumber(kI, 0.0),
+ m_table->GetNumber(kD, 0.0), m_table->GetNumber(kF, 0.0));
+ }
+ } else if (key == kSetpoint && value->IsDouble() &&
+ m_setpoint != value->GetDouble()) {
+ SetSetpoint(value->GetDouble());
+ } else if (key == kEnabled && value->IsBoolean() &&
+ m_enabled != value->GetBoolean()) {
+ if (value->GetBoolean()) {
+ Enable();
+ } else {
+ Disable();
+ }
+ }
+}
+
+void PIDController::UpdateTable() {}
+
+void PIDController::StartLiveWindowMode() { Disable(); }
+
+void PIDController::StopLiveWindowMode() {}