Variables
const double	ROBOT_LENGTH = 1.0

const double	ROBOT_WIDTH = 1.0

const double	WHEEL_BASE = 2. / 3.
	Distance between left and right wheels.

const double	EFF_WHEEL_BASE = 1.40
	Effective distance between wheels.

const double	WHEEL_RADIUS = 0.15

const double	PWM_PER_RAD_PER_SEC = 5000

const double	MAX_DRIVE_PWM = 25000
	Can be up to 2^15 - 1 (32767), but we have limited it because driving at full speed draws a massive amount of current that's too much for our power supply (and full speed is hard to control anyway)

const double	MAX_WHEEL_VEL = WHEEL_RADIUS * MAX_DRIVE_PWM / PWM_PER_RAD_PER_SEC
	Maximum tangential velocity for the rover's wheels.

const double	MAX_DTHETA
	Maximum angular velocity (i.e.

const double	STEER_EPSILON = 10000
	Represents the allowable error in millidegrees for steer motors to still process a drive request.

Detailed Description

Drive constants.

Variable Documentation

const double Constants::Drive::EFF_WHEEL_BASE = 1.40

Effective distance between wheels.

Tweaked so that actual rover angular rate roughly matches the commanded angular rate, based on 2-wheel kinematic model.

const double Constants::Drive::MAX_DTHETA

Initial value:

= kinematics::DiffDriveKinematics(EFF_WHEEL_BASE)

Represents the kinematics of a differential drive.

Definition DiffDriveKinematics.h:14

navtypes::pose_t wheelVelToRobotVel(double lVel, double rVel) const

Given the left and right wheel velocities, find the robot velocity in the robot's reference frame.

Definition DiffDriveKinematics.cpp:12

const double MAX_WHEEL_VEL

Maximum tangential velocity for the rover's wheels.

Definition Constants.cpp:37

const double EFF_WHEEL_BASE

Effective distance between wheels.

Definition Constants.cpp:32

Maximum angular velocity (i.e.

dtheta in setCmdVel()) of the rover.

Computed assuming that the left wheel is going at full speed backwards while the right wheel is going at full speed forwards.

const double Constants::Drive::MAX_WHEEL_VEL = WHEEL_RADIUS * MAX_DRIVE_PWM / PWM_PER_RAD_PER_SEC

Maximum tangential velocity for the rover's wheels.

If the rover is driving straight and not turning, this is the maximum forward velocity (i.e. dx in setCmdVel()) of the rover.

const double Constants::Drive::STEER_EPSILON = 10000

Represents the allowable error in millidegrees for steer motors to still process a drive request.

That is, we make sure all the wheels are close enough to their target rotation before actually driving.