Cpp Example: Follow a Single Path

Using AutoBuilder

The easiest way to create a command to follow a single path is by using AutoBuilder. You must have previously configured AutoBuilder in order to use this option.

See Cpp Example: Build an Auto

#include <pathplanner/lib/path/PathPlannerPath.h>
#include <pathplanner/lib/auto/AutoBuilder.h>

using namespace pathplanner;

frc2::CommandPtr RobotContainer::getAutonomousCommand(){
    // Load the path you want to follow using its name in the GUI
    auto path = PathPlannerPath::fromPathFile("Example Path");

    // Create a path following command using AutoBuilder. This will also trigger event markers.
    return AutoBuilder::followPathWithEvents(path);
}

Manually Create Path Following Commands

Holonomic

#include <pathplanner/lib/commands/FollowPathHolonomic.h>

using namespace pathplanner;

// Assuming this is a method in your drive subsystem
frc2::CommandPtr  DriveSubsystem::followPathCommand(std::string pathName){
    auto path = PathPlannerPath::fromPathFile(pathName);

    // You must wrap the path following command in a FollowPathWithEvents command in order for event markers to work
    return FollowPathWithEvents(
        FollowPathHolonomic(
            path,
            [this](){ return getPose(); }, // Robot pose supplier
            [this](){ return getRobotRelativeSpeeds(); }, // ChassisSpeeds supplier. MUST BE ROBOT RELATIVE
            [this](frc::ChassisSpeeds speeds){ driveRobotRelative(speeds); }, // Method that will drive the robot given ROBOT RELATIVE ChassisSpeeds
            HolonomicPathFollowerConfig( // HolonomicPathFollowerConfig, this should likely live in your Constants class
                PIDConstants(5.0, 0.0, 0.0), // Translation PID constants
                PIDConstants(5.0, 0.0, 0.0), // Rotation PID constants
                4.5_mps, // Max module speed, in m/s
                0.4_m, // Drive base radius in meters. Distance from robot center to furthest module.
                ReplanningConfig() // Default path replanning config. See the API for the options here
            ),
            { this } // Reference to this subsystem to set requirements
        ).ToPtr().Unwrap(),
        path, // FollowPathWithEvents also requires the path
       [this](){ return getPose(); } // FollowPathWithEvents also requires the robot pose supplier
    ).ToPtr();
}

Ramsete

#include <pathplanner/lib/commands/FollowPathRamsete.h>

using namespace pathplanner;

// Assuming this is a method in your drive subsystem
frc2::CommandPtr  DriveSubsystem::followPathCommand(std::string pathName){
    auto path = PathPlannerPath::fromPathFile(pathName);

    // You must wrap the path following command in a FollowPathWithEvents command in order for event markers to work
    return FollowPathWithEvents(
        FollowPathRamsete(
            path,
            [this](){ return getPose(); }, // Robot pose supplier
            [this](){ return getRobotRelativeSpeeds(); }, // ChassisSpeeds supplier. MUST BE ROBOT RELATIVE
            [this](frc::ChassisSpeeds speeds){ driveRobotRelative(speeds); }, // Method that will drive the robot given ROBOT RELATIVE ChassisSpeeds
            ReplanningConfig(), // Default path replanning config. See the API for the options here
            { this } // Reference to this subsystem to set requirements
        ).ToPtr().Unwrap(),
        path, // FollowPathWithEvents also requires the path
       [this](){ return getPose(); } // FollowPathWithEvents also requires the robot pose supplier
    ).ToPtr();
}

LTV

#include <pathplanner/lib/commands/FollowPathLTV.h>

using namespace pathplanner;

// Assuming this is a method in your drive subsystem
frc2::CommandPtr  DriveSubsystem::followPathCommand(std::string pathName){
    auto path = PathPlannerPath::fromPathFile(pathName);

    // You must wrap the path following command in a FollowPathWithEvents command in order for event markers to work
    return FollowPathWithEvents(
        FollowPathLTV(
            path,
            [this](){ return getPose(); }, // Robot pose supplier
            [this](){ return getRobotRelativeSpeeds(); }, // ChassisSpeeds supplier. MUST BE ROBOT RELATIVE
            [this](frc::ChassisSpeeds speeds){ driveRobotRelative(speeds); }, // Method that will drive the robot given ROBOT RELATIVE ChassisSpeeds
            0.02_s, // Robot control loop period in seconds. Default is 0.02
            ReplanningConfig(), // Default path replanning config. See the API for the options here
            { this } // Reference to this subsystem to set requirements
        ).ToPtr().Unwrap(),
        path, // FollowPathWithEvents also requires the path
       [this](){ return getPose(); } // FollowPathWithEvents also requires the robot pose supplier
    ).ToPtr();
}