maspack.spatialmotion

Class RollPitchCoupling

java.lang.Object

maspack.spatialmotion.RigidBodyCoupling

maspack.spatialmotion.RollPitchCoupling

public class RollPitchCoupling
extends RigidBodyCoupling

Implements a two DOF roll-pitch coupling. Frames C and D share a common origin, and the transform from C to D is given by a roll rotation about the z axis, followed by a pitch rotation about the subsequent y axis. Range limits can be placed on both the roll and pitch angles.

Field Summary

Fields inherited from class maspack.spatialmotion.RigidBodyCoupling

BILATERAL, LINEAR, ROTARY, useNewDerivatives

Constructor Summary

Constructors

Constructor and Description
RollPitchCoupling()

Method Summary

Modifier and Type	Method and Description
void	getConstraintInfo(maspack.spatialmotion.RigidBodyCoupling.ConstraintInfo[] info, RigidTransform3d TGD, RigidTransform3d TCD, RigidTransform3d XERR, boolean setEngaged) Computes the constraint frame G and the associated constraint information.
void	getPitchRange(double[] minmax) Gets the minimum and maximum values for the coupling's pitch angle (in radians).
void	getRollPitch(double[] angs, RigidTransform3d TGD)
void	getRollRange(double[] minmax) Gets the minimum and maximum values for the coupling's roll angle (in radians).
boolean	hasRestrictedRange() Returns true if this coupling has a range restriction; this will be true if the range of the roll or pitch angles is less than [-PI, PI].
void	initializeConstraintInfo(maspack.spatialmotion.RigidBodyCoupling.ConstraintInfo[] info)
int	maxUnilaterals() Returns the maximum number of unilateral constraints associated with this coupling.
int	numBilaterals() Returns the number of bilateral constraints associated with this coupling.
void	projectToConstraint(RigidTransform3d TGD, RigidTransform3d TCD) Computes the frame G on the constraint surface which is closest to a given frame C.
void	setPitchRange(double min, double max) Sets the minimum and maximum values for the coupling's pitch angle (in radians).
void	setRollPitch(RigidTransform3d TGD, double[] angs)
void	setRollRange(double min, double max) Sets the minimum and maximum values for the coupling's roll angle (in radians).

Methods inherited from class maspack.spatialmotion.RigidBodyCoupling

findNearestAngle, getAuxState, getBilateralConstraints, getBilateralForceG, getBilateralImpulses, getBreakAccel, getBreakSpeed, getCompliance, getConstraint, getConstraintInfo, getContactDistance, getDamping, getInitialAuxState, getUnilateralConstraints, getUnilateralForceG, getUnilateralImpulses, maxConstraints, numUnilaterals, printConstraintInfo, scaleDistance, setAuxState, setBilateralImpulses, setBreakAccel, setBreakSpeed, setCompliance, setContactDistance, setDamping, setDistanceAndZeroDerivative, setDistancesAndZeroDerivatives, setUnilateralImpulses, skipAuxState, transformGeometry, updateBodyStates, updateConstraintsFromC, updateUnilateralConstraints, zeroImpulses

Methods inherited from class java.lang.Object

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

Constructor Detail

RollPitchCoupling

public RollPitchCoupling()

Method Detail

setRollRange

public void setRollRange(double min,
                         double max)

Sets the minimum and maximum values for the coupling's roll angle (in radians). These values are clipped to the range [-PI,PI].

Parameters:

min - Minimum roll angle

max - Maximum roll angle

getRollRange

public void getRollRange(double[] minmax)

Gets the minimum and maximum values for the coupling's roll angle (in radians).

Parameters:

minmax - used to return the minimum and maximum values

See Also:

setRollRange(double, double)

setPitchRange

public void setPitchRange(double min,
                          double max)

Sets the minimum and maximum values for the coupling's pitch angle (in radians). These values are clipped to the range [-PI,PI].

Parameters:

min - Minimum pitch angle

max - Maximum pitch angle

getPitchRange

public void getPitchRange(double[] minmax)

Gets the minimum and maximum values for the coupling's pitch angle (in radians).

Parameters:

minmax - used to return the minimum and maximum values

See Also:

setPitchRange(double, double)

hasRestrictedRange

public boolean hasRestrictedRange()

Returns true if this coupling has a range restriction; this will be true if the range of the roll or pitch angles is less than [-PI, PI].

Returns:

true if this coupling has a range restriction.

maxUnilaterals

public int maxUnilaterals()

Description copied from class: RigidBodyCoupling

Returns the maximum number of unilateral constraints associated with this coupling.

Specified by:

maxUnilaterals in class RigidBodyCoupling

Returns:

maximum number of unilateral constraints

numBilaterals

public int numBilaterals()

Description copied from class: RigidBodyCoupling

Returns the number of bilateral constraints associated with this coupling.

Specified by:

numBilaterals in class RigidBodyCoupling

Returns:

number of bilateral constraints

projectToConstraint

public void projectToConstraint(RigidTransform3d TGD,
                                RigidTransform3d TCD)

Description copied from class: RigidBodyCoupling

Computes the frame G on the constraint surface which is closest to a given frame C. The input consists of the transform from C to D.

Specified by:

projectToConstraint in class RigidBodyCoupling

Parameters:

TGD - returns the transform from G to D

TCD - transform from frame C to D

getRollPitch

public void getRollPitch(double[] angs,
                         RigidTransform3d TGD)

setRollPitch

public void setRollPitch(RigidTransform3d TGD,
                         double[] angs)

initializeConstraintInfo

public void initializeConstraintInfo(maspack.spatialmotion.RigidBodyCoupling.ConstraintInfo[] info)

Specified by:

initializeConstraintInfo in class RigidBodyCoupling

getConstraintInfo

public void getConstraintInfo(maspack.spatialmotion.RigidBodyCoupling.ConstraintInfo[] info,
                              RigidTransform3d TGD,
                              RigidTransform3d TCD,
                              RigidTransform3d XERR,
                              boolean setEngaged)

Description copied from class: RigidBodyCoupling

Computes the constraint frame G and the associated constraint information. G is determined by projecting C onto the constraint surface.

Information for each constraint wrench is returned through an array of ConstraintInfo objects supplied by the argument info. This array should have a fixed number of elements equal to the number of bilateral constraints plus the maximum number of unilateral constraints. Bilateral constraints appear first, followed by the unilateral constraints. Constraint wrenches and their derivatives (with respect to frame G) are set within the fields wrenchC and dotWrenchC, repsectively. Distances to set within the distance; each of these should be the dot product of the wrench with the linearization of the constraint error TCG. For computing wrench derivatives, this method may use myVelBA, which gives the current velocity of B with repsect to A, in coordinate frame D. Information only needs to be returned for constraints which are potentially active, or engaged. Constraints which are engaged have their ConstraintInfo.engaged field set to a non-zero value. Bilateral constraints are always engaged, and their ConstraintInfo.engaged field is automatically set to 1 by the system. For unilateral constraints, the determination of whether or not the constraint is engaged, and the setting of the engaged field, should be done by this method if the argument setEngaged is true. Otherwise, if setEngaged is false, the method should take the engaged settings as given. Constraints which are engaged are those which are returned by the calls getBilateralConstraints or getUnilateralConstraints.

Specified by:

getConstraintInfo in class RigidBodyCoupling

Parameters:

info - used to return information for each possible constraint wrenches

TGD - returns the transform from G to D

TCD - transform from operation frame C to D

XERR - TODO

setEngaged - if true, this method should determine if the constraint is engaged.