---

rdForce Class Reference

A class that supports the application of a force between two bodies, BodyA and BodyB. More...

#include <rdForce.h>

Inheritance diagram for rdForce:

List of all members.

Public Member Functions
	rdForce (int aBodyA=0, int aBodyB=0, int aNX=1, int aNY=0, int aNYP=0)
	Default constructor.
	rdForce (IDOM_Element *aElement, int aNX=1, int aNY=0, int aNYP=0)
	Construct an actuator from file.
	rdForce (const rdForce &aForce)
	Copy constructor.
virtual	~rdForce ()
	Destructor.
virtual rdActuator *	copy () const
	Copy this actuator.
virtual rdActuator *	copy (IDOM_Element *aElement) const
	Copy this actuator and modify the copy so that it is consistent with a specified XML element node.
rdForce &	operator= (const rdForce &aForce)
	Assignment operator.
virtual void	setControls (const double aX[])
	Set the current values of the controls.
virtual void	getControls (double rX[]) const
	Get the current values of the controls.
void	setBodyA (int aID)
	Set the id of the first body to which the force is applied.
int	getBodyA () const
	Get the id of the first body to which the force is applied.
void	setPointA (const double aPoint[3])
	Set the value of the point on BodyA at which the force is applied.
void	getPointA (double rPoint[3]) const
	Get the value of the point on BodyA at which the force is applied.
void	setForceDirectionA (const double aDirection[3])
	Set the direction in which a positive actuator force is applied to BodyA.
void	getForceDirectionA (double rDirection[3]) const
	Set the direction in which a positive actuator force is applied to BodyA.
void	setBodyB (int aID)
	Set the id of the second body to which the force is applied.
int	getBodyB () const
	Get the id of the second body to which the force is applied.
void	setPointB (const double aPoint[3])
	Set the value of the point on BodyB at which the force is applied.
void	getPointB (double rPoint[3]) const
	Get the value of the point on BodyB at which the force is applied.
void	getForceDirectionB (double rDirection[3]) const
	Get the direction in which a positive actuator force is applied to BodyB.
virtual void	apply ()
	Apply the actuator force to BodyA and BodyB.
virtual void	computeActuation ()
	Compute all quantities necessary for applying the actuator force to the model.
void	computeForceDirectionForBodyB ()
	Compute the force direction for BodyB based on the force direction set for BodyA.
void	computeSpeed ()
	Compute the speed of the actuator.
virtual bool	check () const
	Check that this force actuator has a valid set of states.
void	computeLineOfAction (double aLineOfAction[3]) const
	Compute the vector directed from the point of force application on BodyA to the point of force application on BodyB expressed in the local frame of BodyA.
virtual void	updateObject (bool aDeep=true)
	Update this object based on its XML node.
virtual void	updateNode (bool aDeep=true)
	Update the XML node representing this object.
virtual void	generateNode (IDOM_Element *aParent)
	Generate an XML node representing this object.
void	updateData ()
	Update the member data of this object based on its XML node.
Static Public Attributes
const char	PROP_BODYA [] = "body_A"
const char	PROP_POINTA [] = "point_A"
const char	PROP_DIRECTIONA [] = "direction_A"
const char	PROP_BODYB [] = "body_B"
const char	PROP_POINTB [] = "point_B"
Protected Attributes
int	_bA
	BodyA.
double	_pA [3]
	Point on BodyA expressed in the body-local frame at which the force is applied.
double	_uA [3]
	Unit vector expressed in the local frame of BodyA that specifies the direction a positive actuator force is applied to BodyA.
int	_bB
	BodyB.
double	_pB [3]
	Point on BodyB expressed in the body-local frame at which the force is applied.
double	_uB [3]
	Unit vector expressed in the local frame of BodyB that specifies the direction a positive actuator force is applied to BodyB.
Private Member Functions
void	setNull ()
	Set the data members of this actuator to their null values.

---

Detailed Description

A class that supports the application of a force between two bodies, BodyA and BodyB.

This actuator has no states; the control is simply the force to be applied to the model.

Author:

Frank C. Anderson

Version:

1.0

---

Constructor & Destructor Documentation

rdForce::rdForce (  IDOM_Element *  aElement, int  aNX = 1, int  aNY = 0, int  aNYP = 0 )

Construct an actuator from file. Parameters: aFileName  Name of the file.

rdForce::rdForce (  const rdForce &  aForce  )

Copy constructor. Parameters: aForce  Force to be copied.

---

Member Function Documentation

void rdForce::computeLineOfAction (  double  aLineOfAction[3]  )  const

Compute the vector directed from the point of force application on BodyA to the point of force application on BodyB expressed in the local frame of BodyA. Parameters: rLineOfAction  Line of action expressed in the local frame of BodyA. Todo: Check that the line of action is expressed in the proper frame.

rdActuator * rdForce::copy (  IDOM_Element *  aElement  )  const [virtual]

Copy this actuator and modify the copy so that it is consistent with a specified XML element node. The copy is constructed by first using rdForce::rdForce(IDOM_Element*,int,int) in order to establish the relationship of the rdForce object with the XML node. Then, the assignment operator is used to set all data members of the copy to the values of this rdForce object. Finally, the data members of the copy are updated using rdForce::updateObject(). Parameters: aElement  XML element. Returns: Pointer to a copy of this actuator. Implements rdActuator. Reimplemented in rdLinearSetPoint, rdMuscleZajac, and rdPolynomialSetPoint.

rdActuator * rdForce::copy (   )  const [virtual]

Copy this actuator. The copy constructor for this class is used. Returns: Pointer to a copy of this actuator. Implements rdActuator. Reimplemented in rdLinearSetPoint, rdMuscleZajac, and rdPolynomialSetPoint.

void rdForce::generateNode (  IDOM_Element *  aParent  )  [virtual]

Generate an XML node representing this object. Parameters: aParent  Intended parent of the node to be generated. If aParent is NULL, the intent is for this object to serve as the root element of a new document. See also: rdObject::generateNode() Reimplemented from rdActuator. Reimplemented in rdLinearSetPoint, rdMuscleZajac, rdPolynomialSetPoint, rdSetPoint, and rdContactForce.

int rdForce::getBodyA (   )  const

Get the id of the first body to which the force is applied. Parameters: aID  Body ID.

int rdForce::getBodyB (   )  const

Get the id of the second body to which the force is applied. Parameters: aID  Body ID.

void rdForce::getControls (  double  rX[]  )  const [virtual]

Get the current values of the controls. Parameters: aX  Array of control values. Reimplemented from rdActuator. Reimplemented in rdMuscleZajac.

void rdForce::getForceDirectionA (  double  rDirection[3]  )  const

Set the direction in which a positive actuator force is applied to BodyA. Parameters: rPoint  Point x, y, and z values.

void rdForce::getForceDirectionB (  double  rDirection[3]  )  const

Get the direction in which a positive actuator force is applied to BodyB. Note that the direction of force application on BodyB cannot be set; it is always computed based on the force direction set for BodyA. Parameters: rPoint  Point x, y, and z values.

void rdForce::getPointA (  double  rPoint[3]  )  const

Get the value of the point on BodyA at which the force is applied. Parameters: rPoint  Point x, y, and z values.

void rdForce::getPointB (  double  rPoint[3]  )  const

Get the value of the point on BodyB at which the force is applied. Parameters: rPoint  Point x, y, and z values.

rdForce & rdForce::operator= (  const rdForce &  aForce  )

Assignment operator. Returns: Reference to this object.

void rdForce::setBodyA (  int  aID  )

Set the id of the first body to which the force is applied. Parameters: aID  Body ID.

void rdForce::setBodyB (  int  aID  )

Set the id of the second body to which the force is applied. Parameters: aID  Body ID.

void rdForce::setControls (  const double  aX[]  )  [virtual]

Set the current values of the controls. Parameters: aX  Array of control values. Reimplemented from rdActuator. Reimplemented in rdMuscleZajac.

void rdForce::setForceDirectionA (  const double  aDirection[3]  )

Set the direction in which a positive actuator force is applied to BodyA. Newton's second law states that the force between two bodies is equal and opposite in direction, so when the direction of force on one body is known, the direction on the other body can be calculated. Therefore, the direction of force on BodyB is always computed. Parameters: aDirection  Direction. The direction is normalized. If the magnitude of aDirection is less than rdMath::ZERO, the force direction is set to the zero vector, the effect of which is to prevent any force from being applied.

void rdForce::setPointA (  const double  aPoint[3]  )

Set the value of the point on BodyA at which the force is applied. Parameters: aPoint  Point x, y, and z values.

void rdForce::setPointB (  const double  aPoint[3]  )

Set the value of the point on BodyB at which the force is applied. Parameters: aPoint  Point x, y, and z values.

void rdForce::updateData (   )

Update the member data of this object based on its XML node. Member objects (children) are not updated. Reimplemented from rdActuator. Reimplemented in rdLinearSetPoint, rdMuscleZajac, rdPolynomialSetPoint, rdSetPoint, and rdContactForce.

void rdForce::updateNode (  bool  aDeep = true  )  [virtual]

Update the XML node representing this object. Parameters: aDeep  If true, update the XML node of this object AND the XML nodes of all class members that are rdObjects (child nodes); if false, update only the XML node of this object without updating the XML nodes of its children. Reimplemented from rdActuator. Reimplemented in rdLinearSetPoint, rdMuscleZajac, rdPolynomialSetPoint, rdSetPoint, and rdContactForce.

void rdForce::updateObject (  bool  aDeep = true  )  [virtual]

Update this object based on its XML node. Parameters: aDeep  If true, update this object and all its child objects (that is, member variables that are rdObject's); if false, update only the member variables that are not rdObject's. Reimplemented from rdActuator. Reimplemented in rdLinearSetPoint, rdMuscleZajac, rdPolynomialSetPoint, rdSetPoint, and rdContactForce.

---

The documentation for this class was generated from the following files:

• rdForce.h
• rdForce.cpp

---