Files
allwpilib/robotpyExamples/SwerveDrivePoseEstimator/drivetrain.py
PJ Reiniger 8f9fc4d1b6 [copybara] Import robotpy examples (#8608)
GitOrigin-RevId: 9ba4bc3040fa7e772f5a594039e78fc6c43d114e
2026-02-20 15:30:35 -08:00

112 lines
4.0 KiB
Python

#
# Copyright (c) FIRST and other WPILib contributors.
# Open Source Software; you can modify and/or share it under the terms of
# the WPILib BSD license file in the root directory of this project.
#
import math
import wpilib
import wpimath
import wpimath.units
import swervemodule
from exampleglobalmeasurementsensor import ExampleGlobalMeasurementSensor
class Drivetrain:
"""Represents a swerve drive style drivetrain."""
kMaxSpeed = 3.0 # 3 meters per second
kMaxAngularSpeed = math.pi # 1/2 rotation per second
def __init__(self) -> None:
self.frontLeftLocation = wpimath.Translation2d(0.381, 0.381)
self.frontRightLocation = wpimath.Translation2d(0.381, -0.381)
self.backLeftLocation = wpimath.Translation2d(-0.381, 0.381)
self.backRightLocation = wpimath.Translation2d(-0.381, -0.381)
self.frontLeft = swervemodule.SwerveModule(1, 2, 0, 1, 2, 3)
self.frontRight = swervemodule.SwerveModule(3, 4, 4, 5, 6, 7)
self.backLeft = swervemodule.SwerveModule(5, 6, 8, 9, 10, 11)
self.backRight = swervemodule.SwerveModule(7, 8, 12, 13, 14, 15)
self.imu = wpilib.OnboardIMU(wpilib.OnboardIMU.MountOrientation.kFlat)
self.kinematics = wpimath.SwerveDrive4Kinematics(
self.frontLeftLocation,
self.frontRightLocation,
self.backLeftLocation,
self.backRightLocation,
)
# Here we use SwerveDrivePoseEstimator so that we can fuse odometry readings. The numbers
# used below are robot specific, and should be tuned.
self.poseEstimator = wpimath.SwerveDrive4PoseEstimator(
self.kinematics,
self.imu.getRotation2d(),
(
self.frontLeft.getPosition(),
self.frontRight.getPosition(),
self.backLeft.getPosition(),
self.backRight.getPosition(),
),
wpimath.Pose2d(),
(0.05, 0.05, wpimath.units.degreesToRadians(5)),
(0.5, 0.5, wpimath.units.degreesToRadians(30)),
)
self.imu.resetYaw()
def drive(
self,
xSpeed: float,
ySpeed: float,
rot: float,
fieldRelative: bool,
period: float,
) -> None:
"""Method to drive the robot using joystick info.
:param xSpeed: Speed of the robot in the x direction (forward).
:param ySpeed: Speed of the robot in the y direction (sideways).
:param rot: Angular rate of the robot.
:param fieldRelative: Whether the provided x and y speeds are relative to the field.
"""
chassisSpeeds = wpimath.ChassisSpeeds(xSpeed, ySpeed, rot)
if fieldRelative:
chassisSpeeds = chassisSpeeds.toRobotRelative(
self.poseEstimator.getEstimatedPosition().rotation()
)
chassisSpeeds = chassisSpeeds.discretize(period)
states = self.kinematics.toSwerveModuleStates(chassisSpeeds)
wpimath.SwerveDrive4Kinematics.desaturateWheelSpeeds(states, self.kMaxSpeed)
self.frontLeft.setDesiredState(states[0])
self.frontRight.setDesiredState(states[1])
self.backLeft.setDesiredState(states[2])
self.backRight.setDesiredState(states[3])
def updateOdometry(self) -> None:
"""Updates the field relative position of the robot."""
self.poseEstimator.update(
self.imu.getRotation2d(),
(
self.frontLeft.getPosition(),
self.frontRight.getPosition(),
self.backLeft.getPosition(),
self.backRight.getPosition(),
),
)
# Also apply vision measurements. We use 0.3 seconds in the past as an example -- on
# a real robot, this must be calculated based either on latency or timestamps.
self.poseEstimator.addVisionMeasurement(
ExampleGlobalMeasurementSensor.getEstimatedGlobalPose(
self.poseEstimator.getEstimatedPosition()
),
wpilib.Timer.getTimestamp() - 0.3,
)