rp1.rossum
Class RsWheelSystem

java.lang.Object
  rp1.rossum.RsComponent
      rp1.rossum.RsBodyPart
          rp1.rossum.RsActuator
              rp1.rossum.RsWheelSystem

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable

Direct Known Subclasses:

RsAckermanSteering, RsDifferentialSteering

public abstract class RsWheelSystem
extends RsActuator

This is the abstract base class for all locomotor classes. Eventually, implementations are planned for the following classes

• RsDifferentialSteering - Wheelchair-type steering (implemented)
• RsAckermanSteering - Automobile-type steering (in progress)
• RsOmniDrive - Omni-directional drive (planned)
• RsSkidSteer - Tank-style drive (planned)

A certain group of utility methods will be included with this group.

• getMotionRequest - get motion request for a specific (x,y) goal position
• getMotionRequestForPivot - get motion request for a stop-and-pivot to face goal

Given the robot's current motion and a goal position (x,y) given in the robot's frame of reference coordinate system, these utilities provide a motion request to either get the robot to the x,y (getMotionRequest) or pivot it to face the goal point (getMotionRequestForPivot). Note that while RsWheelSystem implements these methods, some of the derived classes will override them. For instance, an Ackerman (automobile) drive can't perform a pivot. So it overrides getMotionRequestForPivot to always return a null.

Note that in the current version of RP1, a wheel system is non-interactive. This limitation is due to implementation problems to be resolved later. If the wheels are contained within the general chassis of the robot, this is not a problem. On some designs, where the wheels are large compared to the robot, it is common to place them in an "outboard" position. In such a case, collision issues are relevant... model these by creating a body shape with the same "footprint" as the wheels.

See Also:

Serialized Form

Constructor Summary

RsWheelSystem()

Method Summary

void	addDefaultCasterWheel(double x, double y, double wheelRadius, double wheelWidth) Provides a convenience function for adding a default caster wheel to the system.
void	addDefaultWheels(double wheelRadius, double wheelWidth)
void	addWheel(RsWheel w)
void	applyMotion(RsMotion motion)
RsMotion	computeMotion(RsMotion start, double startTime, RsMotionRequest request)
void	copyStateData(RsBodyPart dataSource)
double	getDriveWheelRadius()
RsMotionRequest	getMotionRequest(double x, double y, double speed) Given a goal position defined in x/y coordinates in the robots frame of reference, getMotionRequest computes a motion request that will cause the robot to move from its current position to the goal.
RsMotionRequest	getMotionRequestForPivot(double x, double y, double speed) Given a goal position defined in x/y coordinates in the robot's frame of reference, getMotionRequestForPivot computes a pivot maneuver that will cause the robot to face the goal.
double	getTrackWidth()
double	getWheelBase()
RsWheel	getWheelForID(int wheelID)
RsWheel[]	getWheels()
void	paint(java.awt.Graphics g, RsTransform gt)
void	resetStateData() resetStateData is usually called when a placement is established.
void	setFillColor(java.awt.Color fillColor) This method, which overrides that of the parent class, sets the fill color for all wheel objects that were added to the wheel system prior to its invocation.
void	setLineColor(java.awt.Color lineColor) This method, which overrides that of the parent class, sets the line color for all wheel objects that were added to the wheel system prior to its invocation.

Methods inherited from class rp1.rossum.RsActuator

getPartsArray

Methods inherited from class rp1.rossum.RsBodyPart

getFillColor, getHot, getID, getLineColor, getName, isASensor, searchForCollisions, setHot, setHotFillColor, setHotLineColor, setName

Methods inherited from class rp1.rossum.RsComponent

clone

Methods inherited from class java.lang.Object

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

Constructor Detail

RsWheelSystem

public RsWheelSystem()

Method Detail

addWheel

public void addWheel(RsWheel w)

addDefaultWheels

public void addDefaultWheels(double wheelRadius,
                             double wheelWidth)

getTrackWidth

public double getTrackWidth()

getWheelBase

public double getWheelBase()

getDriveWheelRadius

public double getDriveWheelRadius()

setFillColor

public void setFillColor(java.awt.Color fillColor)

This method, which overrides that of the parent class, sets the fill color for all wheel objects that were added to the wheel system prior to its invocation.

Overrides:

setFillColor in class RsBodyPart

setLineColor

public void setLineColor(java.awt.Color lineColor)

This method, which overrides that of the parent class, sets the line color for all wheel objects that were added to the wheel system prior to its invocation.

Overrides:

setLineColor in class RsBodyPart

paint

public void paint(java.awt.Graphics g,
                  RsTransform gt)

Overrides:

paint in class RsActuator

applyMotion

public void applyMotion(RsMotion motion)

computeMotion

public RsMotion computeMotion(RsMotion start,
                              double startTime,
                              RsMotionRequest request)

getMotionRequest

public RsMotionRequest getMotionRequest(double x,
                                        double y,
                                        double speed)

Given a goal position defined in x/y coordinates in the robots frame of reference, getMotionRequest computes a motion request that will cause the robot to move from its current position to the goal. If the goal is not directly in front or behind the robot, the path will follow the arc of a circle tangent to the robot's current orientation and intersecting both its current position and the goal position. Note that if a particular locomotion cannot satisfy the requirements of the request (for example, the application requests too tight a turn for an automobile-style steering system), this method returns a null.

Parameters:

x - x coordiante of goal in robot's frame of reference (meters)

y - y coordinate of goal in robot's frame of reference (meters)

speed - speed at which robot is requested to travel (meters/sec)

getMotionRequestForPivot

public RsMotionRequest getMotionRequestForPivot(double x,
                                                double y,
                                                double speed)

Given a goal position defined in x/y coordinates in the robot's frame of reference, getMotionRequestForPivot computes a pivot maneuver that will cause the robot to face the goal. Note that not all locomotion systems support pivot maneuvers. For those that do not, this method always returns a null.

Parameters:

x - x coordiante of goal in robot's frame of reference (meters)

y - y coordinate of goal in robot's frame of reference (meters)

speed - rotational speed at which robot is requested to pivot (radians/sec)

resetStateData

public void resetStateData()

Description copied from class: RsBodyPart

resetStateData is usually called when a placement is established. it is implemented as a do-nothing and overridden by derived classes according to their specific behaviors

Overrides:

resetStateData in class RsBodyPart

copyStateData

public void copyStateData(RsBodyPart dataSource)

Overrides:

copyStateData in class RsBodyPart

addDefaultCasterWheel

public void addDefaultCasterWheel(double x,
                                  double y,
                                  double wheelRadius,
                                  double wheelWidth)

Provides a convenience function for adding a default caster wheel to the system. There is nothing special about the design of this caster wheel, and this method is included simply as an example.

getWheelForID

public RsWheel getWheelForID(int wheelID)

getWheels

public RsWheel[] getWheels()