Package edu.wpi.first.math.trajectory.constraint

Class DifferentialDriveVoltageConstraint

java.lang.Object

edu.wpi.first.math.trajectory.constraint.DifferentialDriveVoltageConstraint

All Implemented Interfaces:

TrajectoryConstraint

public class DifferentialDriveVoltageConstraint
extends Object
implements TrajectoryConstraint

A class that enforces constraints on differential drive voltage expenditure based on the motor dynamics and the drive kinematics. Ensures that the acceleration of any wheel of the robot while following the trajectory is never higher than what can be achieved with the given maximum voltage.

Nested Class Summary

Nested classes/interfaces inherited from interface edu.wpi.first.math.trajectory.constraint.TrajectoryConstraint

TrajectoryConstraint.MinMax

Constructor Summary

Constructors

Constructor	Description
DifferentialDriveVoltageConstraint(SimpleMotorFeedforward feedforward, DifferentialDriveKinematics kinematics, double maxVoltage)	Creates a new DifferentialDriveVoltageConstraint.

Method Summary

Modifier and Type	Method	Description
double	getMaxVelocityMetersPerSecond(Pose2d poseMeters, double curvatureRadPerMeter, double velocityMetersPerSecond)	Returns the max velocity given the current pose and curvature.
TrajectoryConstraint.MinMax	getMinMaxAccelerationMetersPerSecondSq(Pose2d poseMeters, double curvatureRadPerMeter, double velocityMetersPerSecond)	Returns the minimum and maximum allowable acceleration for the trajectory given pose, curvature, and speed.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

DifferentialDriveVoltageConstraint

public DifferentialDriveVoltageConstraint(SimpleMotorFeedforward feedforward, DifferentialDriveKinematics kinematics, double maxVoltage)

Creates a new DifferentialDriveVoltageConstraint.

Parameters:

feedforward - A feedforward component describing the behavior of the drive.

kinematics - A kinematics component describing the drive geometry.

maxVoltage - The maximum voltage available to the motors while following the path. Should be somewhat less than the nominal battery voltage (12V) to account for "voltage sag" due to current draw.

Method Details

getMaxVelocityMetersPerSecond

public double getMaxVelocityMetersPerSecond(Pose2d poseMeters, double curvatureRadPerMeter, double velocityMetersPerSecond)

Description copied from interface: TrajectoryConstraint

Returns the max velocity given the current pose and curvature.

Specified by:

getMaxVelocityMetersPerSecond in interface TrajectoryConstraint

Parameters:

poseMeters - The pose at the current point in the trajectory.

curvatureRadPerMeter - The curvature at the current point in the trajectory.

velocityMetersPerSecond - The velocity at the current point in the trajectory before constraints are applied.

Returns:

The absolute maximum velocity.

getMinMaxAccelerationMetersPerSecondSq

public TrajectoryConstraint.MinMax getMinMaxAccelerationMetersPerSecondSq(Pose2d poseMeters, double curvatureRadPerMeter, double velocityMetersPerSecond)

Description copied from interface: TrajectoryConstraint

Returns the minimum and maximum allowable acceleration for the trajectory given pose, curvature, and speed.

Specified by:

getMinMaxAccelerationMetersPerSecondSq in interface TrajectoryConstraint

Parameters:

poseMeters - The pose at the current point in the trajectory.

curvatureRadPerMeter - The curvature at the current point in the trajectory.

velocityMetersPerSecond - The speed at the current point in the trajectory.

Returns:

The min and max acceleration bounds.