Add RamseteCommand (#1951)

wpilibcExamples/src/main/cpp/examples/GyroDriveCommands/cpp/subsystems/DriveSubsystem.cpp

@@ -47,7 +47,7 @@ void DriveSubsystem::SetMaxOutput(double maxOutput) {
 }
 
 double DriveSubsystem::GetHeading() {
-  return std::remainder(m_gyro.GetAngle(), 360);
+  return std::remainder(m_gyro.GetAngle(), 360) * (kGyroReversed ? -1. : 1.);
 }
 
 double DriveSubsystem::GetTurnRate() {

wpilibcExamples/src/main/cpp/examples/GyroDriveCommands/include/Constants.h

@@ -33,7 +33,7 @@ const double kEncoderDistancePerPulse =
     // Assumes the encoders are directly mounted on the wheel shafts
     (kWheelDiameterInches * 3.142) / static_cast<double>(kEncoderCPR);
 
-const bool kGyroReversed = false;
+const bool kGyroReversed = true;
 
 const double kStabilizationP = 1;
 const double kStabilizationI = .5;

wpilibcExamples/src/main/cpp/examples/RamseteCommand/cpp/Robot.cpp

@@ -0,0 +1,71 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2017-2019 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "Robot.h"
+
+#include <frc/smartdashboard/SmartDashboard.h>
+#include <frc2/command/CommandScheduler.h>
+
+void Robot::RobotInit() {}
+
+/**
+ * This function is called every robot packet, no matter the mode. Use
+ * this for items like diagnostics that you want to run during disabled,
+ * autonomous, teleoperated and test.
+ *
+ * <p> This runs after the mode specific periodic functions, but before
+ * LiveWindow and SmartDashboard integrated updating.
+ */
+void Robot::RobotPeriodic() { frc2::CommandScheduler::GetInstance().Run(); }
+
+/**
+ * This function is called once each time the robot enters Disabled mode. You
+ * can use it to reset any subsystem information you want to clear when the
+ * robot is disabled.
+ */
+void Robot::DisabledInit() {}
+
+void Robot::DisabledPeriodic() {}
+
+/**
+ * This autonomous runs the autonomous command selected by your {@link
+ * RobotContainer} class.
+ */
+void Robot::AutonomousInit() {
+  m_autonomousCommand = m_container.GetAutonomousCommand();
+
+  if (m_autonomousCommand != nullptr) {
+    m_autonomousCommand->Schedule();
+  }
+}
+
+void Robot::AutonomousPeriodic() {}
+
+void Robot::TeleopInit() {
+  // This makes sure that the autonomous stops running when
+  // teleop starts running. If you want the autonomous to
+  // continue until interrupted by another command, remove
+  // this line or comment it out.
+  if (m_autonomousCommand != nullptr) {
+    m_autonomousCommand->Cancel();
+    m_autonomousCommand = nullptr;
+  }
+}
+
+/**
+ * This function is called periodically during operator control.
+ */
+void Robot::TeleopPeriodic() {}
+
+/**
+ * This function is called periodically during test mode.
+ */
+void Robot::TestPeriodic() {}
+
+#ifndef RUNNING_FRC_TESTS
+int main() { return frc::StartRobot<Robot>(); }
+#endif

wpilibcExamples/src/main/cpp/examples/RamseteCommand/cpp/RobotContainer.cpp

@@ -0,0 +1,87 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2019 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "RobotContainer.h"
+
+#include <frc/controller/PIDController.h>
+#include <frc/controller/RamseteController.h>
+#include <frc/shuffleboard/Shuffleboard.h>
+#include <frc/trajectory/Trajectory.h>
+#include <frc/trajectory/TrajectoryGenerator.h>
+#include <frc/trajectory/constraint/DifferentialDriveKinematicsConstraint.h>
+#include <frc2/command/InstantCommand.h>
+#include <frc2/command/RamseteCommand.h>
+#include <frc2/command/SequentialCommandGroup.h>
+#include <frc2/command/button/JoystickButton.h>
+
+RobotContainer::RobotContainer() {
+  // Initialize all of your commands and subsystems here
+
+  // Configure the button bindings
+  ConfigureButtonBindings();
+
+  // Set up default drive command
+  m_drive.SetDefaultCommand(frc2::RunCommand(
+      [this] {
+        m_drive.ArcadeDrive(
+            m_driverController.GetY(frc::GenericHID::kLeftHand),
+            m_driverController.GetX(frc::GenericHID::kRightHand));
+      },
+      {&m_drive}));
+}
+
+void RobotContainer::ConfigureButtonBindings() {
+  // Configure your button bindings here
+
+  // While holding the shoulder button, drive at half speed
+  frc2::JoystickButton(&m_driverController, 6)
+      .WhenPressed(&m_driveHalfSpeed)
+      .WhenReleased(&m_driveFullSpeed);
+}
+
+frc2::Command* RobotContainer::GetAutonomousCommand() {
+  // Set up config for trajectory
+  frc::TrajectoryConfig config(AutoConstants::kMaxSpeed,
+                               AutoConstants::kMaxAcceleration);
+  // Add kinematics to ensure max speed is actually obeyed
+  config.SetKinematics(DriveConstants::kDriveKinematics);
+
+  // An example trajectory to follow.  All units in meters.
+  auto exampleTrajectory = frc::TrajectoryGenerator::GenerateTrajectory(
+      // Start at the origin facing the +X direction
+      frc::Pose2d(0_m, 0_m, frc::Rotation2d(0_deg)),
+      // Pass through these two interior waypoints, making an 's' curve path
+      {frc::Translation2d(1_m, 1_m), frc::Translation2d(2_m, -1_m)},
+      // End 3 meters straight ahead of where we started, facing forward
+      frc::Pose2d(3_m, 0_m, frc::Rotation2d(0_deg)),
+      // Pass the config
+      config);
+
+  frc2::RamseteCommand ramseteCommand(
+      exampleTrajectory, [this]() { return m_drive.GetPose(); },
+      frc::RamseteController(AutoConstants::kRamseteB,
+                             AutoConstants::kRamseteZeta),
+      DriveConstants::ks, DriveConstants::kv, DriveConstants::ka,
+      DriveConstants::kDriveKinematics,
+      [this] {
+        return units::meters_per_second_t(m_drive.GetLeftEncoder().GetRate());
+      },
+      [this] {
+        return units::meters_per_second_t(m_drive.GetRightEncoder().GetRate());
+      },
+      frc2::PIDController(DriveConstants::kPDriveVel, 0, 0),
+      frc2::PIDController(DriveConstants::kPDriveVel, 0, 0),
+      [this](auto left, auto right) {
+        m_drive.TankDrive(left / 12_V, right / 12_V);
+      },
+      {&m_drive});
+
+  // no auto
+  return new frc2::SequentialCommandGroup(
+      std::move(ramseteCommand),
+      frc2::InstantCommand([this] { m_drive.TankDrive(0, 0); }, {}));
+}

wpilibcExamples/src/main/cpp/examples/RamseteCommand/cpp/subsystems/DriveSubsystem.cpp

@@ -0,0 +1,75 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2019 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "subsystems/DriveSubsystem.h"
+
+#include <units/units.h>
+
+#include <frc/geometry/Rotation2d.h>
+#include <frc/kinematics/DifferentialDriveWheelSpeeds.h>
+
+using namespace DriveConstants;
+
+DriveSubsystem::DriveSubsystem()
+    : m_left1{kLeftMotor1Port},
+      m_left2{kLeftMotor2Port},
+      m_right1{kRightMotor1Port},
+      m_right2{kRightMotor2Port},
+      m_leftEncoder{kLeftEncoderPorts[0], kLeftEncoderPorts[1]},
+      m_rightEncoder{kRightEncoderPorts[0], kRightEncoderPorts[1]},
+      m_odometry{kDriveKinematics, frc::Pose2d()} {
+  // Set the distance per pulse for the encoders
+  m_leftEncoder.SetDistancePerPulse(kEncoderDistancePerPulse);
+  m_rightEncoder.SetDistancePerPulse(kEncoderDistancePerPulse);
+}
+
+void DriveSubsystem::Periodic() {
+  // Implementation of subsystem periodic method goes here.
+  m_odometry.Update(frc::Rotation2d(units::degree_t(GetHeading())),
+                    frc::DifferentialDriveWheelSpeeds{
+                        units::meters_per_second_t(m_leftEncoder.GetRate()),
+                        units::meters_per_second_t(m_rightEncoder.GetRate())});
+}
+
+void DriveSubsystem::ArcadeDrive(double fwd, double rot) {
+  m_drive.ArcadeDrive(fwd, rot);
+}
+
+void DriveSubsystem::TankDrive(double left, double right) {
+  m_drive.TankDrive(left, right, false);
+}
+
+void DriveSubsystem::ResetEncoders() {
+  m_leftEncoder.Reset();
+  m_rightEncoder.Reset();
+}
+
+double DriveSubsystem::GetAverageEncoderDistance() {
+  return (m_leftEncoder.GetDistance() + m_rightEncoder.GetDistance()) / 2.;
+}
+
+frc::Encoder& DriveSubsystem::GetLeftEncoder() { return m_leftEncoder; }
+
+frc::Encoder& DriveSubsystem::GetRightEncoder() { return m_rightEncoder; }
+
+void DriveSubsystem::SetMaxOutput(double maxOutput) {
+  m_drive.SetMaxOutput(maxOutput);
+}
+
+double DriveSubsystem::GetHeading() {
+  return std::remainder(m_gyro.GetAngle(), 360) * (kGyroReversed ? -1. : 1.);
+}
+
+double DriveSubsystem::GetTurnRate() {
+  return m_gyro.GetRate() * (kGyroReversed ? -1. : 1.);
+}
+
+frc::Pose2d DriveSubsystem::GetPose() { return m_odometry.GetPose(); }
+
+void DriveSubsystem::ResetOdometry(frc::Pose2d pose) {
+  m_odometry.ResetPosition(pose);
+}

wpilibcExamples/src/main/cpp/examples/RamseteCommand/include/Constants.h

@@ -0,0 +1,71 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2019 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include <units/units.h>
+
+#include <frc/kinematics/DifferentialDriveKinematics.h>
+#include <frc/trajectory/constraint/DifferentialDriveKinematicsConstraint.h>
+
+#pragma once
+
+/**
+ * The Constants header provides a convenient place for teams to hold robot-wide
+ * numerical or bool constants.  This should not be used for any other purpose.
+ *
+ * It is generally a good idea to place constants into subsystem- or
+ * command-specific namespaces within this header, which can then be used where
+ * they are needed.
+ */
+
+namespace DriveConstants {
+const int kLeftMotor1Port = 0;
+const int kLeftMotor2Port = 1;
+const int kRightMotor1Port = 2;
+const int kRightMotor2Port = 3;
+
+const int kLeftEncoderPorts[]{0, 1};
+const int kRightEncoderPorts[]{2, 3};
+const bool kLeftEncoderReversed = false;
+const bool kRightEncoderReversed = true;
+
+const auto kTrackwidth = .6_m;
+const frc::DifferentialDriveKinematics kDriveKinematics(kTrackwidth);
+
+const int kEncoderCPR = 1024;
+const double kWheelDiameterInches = 6;
+const double kEncoderDistancePerPulse =
+    // Assumes the encoders are directly mounted on the wheel shafts
+    (kWheelDiameterInches * 3.142) / static_cast<double>(kEncoderCPR);
+
+const bool kGyroReversed = true;
+
+// These are example values only - DO NOT USE THESE FOR YOUR OWN ROBOT!
+// These characterization values MUST be determined either experimentally or
+// theoretically for *your* robot's drive. The RobotPy Characterization
+// Toolsuite provides a convenient tool for obtaining these values for your
+// robot.
+const auto ks = 1_V;
+const auto kv = .8 * 1_V * 1_s / 1_m;
+const auto ka = .15 * 1_V * 1_s * 1_s / 1_m;
+
+// Example value only - as above, this must be tuned for your drive!
+const double kPDriveVel = .5;
+}  // namespace DriveConstants
+
+namespace AutoConstants {
+const auto kMaxSpeed = 3_mps;
+const auto kMaxAcceleration = 3_mps_sq;
+
+// Reasonable baseline values for a RAMSETE follower in units of meters and
+// seconds
+const double kRamseteB = 2;
+const double kRamseteZeta = .7;
+}  // namespace AutoConstants
+
+namespace OIConstants {
+const int kDriverControllerPort = 1;
+}  // namespace OIConstants

wpilibcExamples/src/main/cpp/examples/RamseteCommand/include/Robot.h

@@ -0,0 +1,33 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2017-2019 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 <frc/TimedRobot.h>
+#include <frc2/command/Command.h>
+
+#include "RobotContainer.h"
+
+class Robot : public frc::TimedRobot {
+ public:
+  void RobotInit() override;
+  void RobotPeriodic() override;
+  void DisabledInit() override;
+  void DisabledPeriodic() override;
+  void AutonomousInit() override;
+  void AutonomousPeriodic() override;
+  void TeleopInit() override;
+  void TeleopPeriodic() override;
+  void TestPeriodic() override;
+
+ private:
+  // Have it null by default so that if testing teleop it
+  // doesn't have undefined behavior and potentially crash.
+  frc2::Command* m_autonomousCommand = nullptr;
+
+  RobotContainer m_container;
+};

wpilibcExamples/src/main/cpp/examples/RamseteCommand/include/RobotContainer.h

@@ -0,0 +1,53 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2019 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 <frc/XboxController.h>
+#include <frc/controller/PIDController.h>
+#include <frc/smartdashboard/SendableChooser.h>
+#include <frc2/command/Command.h>
+#include <frc2/command/InstantCommand.h>
+#include <frc2/command/PIDCommand.h>
+#include <frc2/command/ParallelRaceGroup.h>
+#include <frc2/command/RunCommand.h>
+
+#include "Constants.h"
+#include "subsystems/DriveSubsystem.h"
+
+/**
+ * This class is where the bulk of the robot should be declared.  Since
+ * Command-based is a "declarative" paradigm, very little robot logic should
+ * actually be handled in the {@link Robot} periodic methods (other than the
+ * scheduler calls).  Instead, the structure of the robot (including subsystems,
+ * commands, and button mappings) should be declared here.
+ */
+class RobotContainer {
+ public:
+  RobotContainer();
+
+  frc2::Command* GetAutonomousCommand();
+
+ private:
+  // The driver's controller
+  frc::XboxController m_driverController{OIConstants::kDriverControllerPort};
+
+  // The robot's subsystems and commands are defined here...
+
+  // The robot's subsystems
+  DriveSubsystem m_drive;
+
+  frc2::InstantCommand m_driveHalfSpeed{[this] { m_drive.SetMaxOutput(.5); },
+                                        {}};
+  frc2::InstantCommand m_driveFullSpeed{[this] { m_drive.SetMaxOutput(1); },
+                                        {}};
+
+  // The chooser for the autonomous routines
+  frc::SendableChooser<frc2::Command*> m_chooser;
+
+  void ConfigureButtonBindings();
+};

wpilibcExamples/src/main/cpp/examples/RamseteCommand/include/subsystems/DriveSubsystem.h

@@ -0,0 +1,141 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2019 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 <frc/ADXRS450_Gyro.h>
+#include <frc/Encoder.h>
+#include <frc/PWMVictorSPX.h>
+#include <frc/SpeedControllerGroup.h>
+#include <frc/drive/DifferentialDrive.h>
+#include <frc/geometry/Pose2d.h>
+#include <frc/kinematics/DifferentialDriveOdometry.h>
+#include <frc2/command/SubsystemBase.h>
+
+#include "Constants.h"
+
+class DriveSubsystem : public frc2::SubsystemBase {
+ public:
+  DriveSubsystem();
+
+  /**
+   * Will be called periodically whenever the CommandScheduler runs.
+   */
+  void Periodic() override;
+
+  // Subsystem methods go here.
+
+  /**
+   * Drives the robot using arcade controls.
+   *
+   * @param fwd the commanded forward movement
+   * @param rot the commanded rotation
+   */
+  void ArcadeDrive(double fwd, double rot);
+
+  /**
+   * Drives the robot using tank controls.  Does not square inputs to enable
+   * composition with external controllers.
+   *
+   * @param left the commanded left output
+   * @param right the commanded right output
+   */
+  void TankDrive(double left, double right);
+
+  /**
+   * Resets the drive encoders to currently read a position of 0.
+   */
+  void ResetEncoders();
+
+  /**
+   * Gets the average distance of the TWO encoders.
+   *
+   * @return the average of the TWO encoder readings
+   */
+  double GetAverageEncoderDistance();
+
+  /**
+   * Gets the left drive encoder.
+   *
+   * @return the left drive encoder
+   */
+  frc::Encoder& GetLeftEncoder();
+
+  /**
+   * Gets the right drive encoder.
+   *
+   * @return the right drive encoder
+   */
+  frc::Encoder& GetRightEncoder();
+
+  /**
+   * Sets the max output of the drive.  Useful for scaling the drive to drive
+   * more slowly.
+   *
+   * @param maxOutput the maximum output to which the drive will be constrained
+   */
+  void SetMaxOutput(double maxOutput);
+
+  /**
+   * Returns the heading of the robot.
+   *
+   * @return the robot's heading in degrees, from 180 to 180
+   */
+  double GetHeading();
+
+  /**
+   * Returns the turn rate of the robot.
+   *
+   * @return The turn rate of the robot, in degrees per second
+   */
+  double GetTurnRate();
+
+  /**
+   * Returns the currently-estimated pose of the robot.
+   *
+   * @return The pose.
+   */
+  frc::Pose2d GetPose();
+
+  /**
+   * Resets the odometry to the specified pose.
+   *
+   * @param pose The pose to which to set the odometry.
+   */
+  void ResetOdometry(frc::Pose2d pose);
+
+ private:
+  // Components (e.g. motor controllers and sensors) should generally be
+  // declared private and exposed only through public methods.
+
+  // The motor controllers
+  frc::PWMVictorSPX m_left1;
+  frc::PWMVictorSPX m_left2;
+  frc::PWMVictorSPX m_right1;
+  frc::PWMVictorSPX m_right2;
+
+  // The motors on the left side of the drive
+  frc::SpeedControllerGroup m_leftMotors{m_left1, m_left2};
+
+  // The motors on the right side of the drive
+  frc::SpeedControllerGroup m_rightMotors{m_right1, m_right2};
+
+  // The robot's drive
+  frc::DifferentialDrive m_drive{m_leftMotors, m_rightMotors};
+
+  // The left-side drive encoder
+  frc::Encoder m_leftEncoder;
+
+  // The right-side drive encoder
+  frc::Encoder m_rightEncoder;
+
+  // The gyro sensor
+  frc::ADXRS450_Gyro m_gyro;
+
+  // Odometry class for tracking robot pose
+  frc::DifferentialDriveOdometry m_odometry;
+};

wpilibcExamples/src/main/cpp/examples/examples.json

@@ -355,5 +355,18 @@
     ],
     "foldername": "DifferentialDriveBot",
     "gradlebase": "cpp"
+  },
+  {
+    "name:": "RamseteCommand",
+    "description": "An example command-based robot demonstrating the use of a RamseteCommand to follow a pregenerated trajectory.",
+    "tags": [
+      "RamseteCommand",
+      "PID",
+      "Ramsete",
+      "Trajectory",
+      "Path following"
+    ],
+    "foldername": "RamseteCommand",
+    "gradlebase": "cpp"
   }
 ]