Class defining kinematics of a robot, and commonly used functions. More...

#include <RobotKinematics3D.h>

Inheritance diagram for RobotKinematics3D:

Public Member Functions
virtual std::string	LinkName (int i) const

void	Initialize (int numLinks)
	Initializer: blank robot.

void	InitializeRigidObject ()
	Initializer: rigid object.

void	Merge (const std::vector< RobotKinematics3D * > &robots)
	Initializer: merge some robots into one big robot.

void	Subset (const RobotKinematics3D &robot, const std::vector< int > &subset)
	Initializer: select a subset of the robot links as DOFs.

void	UpdateFrames ()
	based on the values in q, update the frames T

void	UpdateSelectedFrames (int link, int root=-1)
	based on the values in q, update the frames of link T up to the root

void	UpdateConfig (const Config &q)
	sets the current config q and updates frames

bool	InJointLimits (const Config &q) const
	returns true if q is within joint limits

void	NormalizeAngles (Config &q) const
	normalizes angles in q to be within the range [qmin,qmax]

Real	GetTotalMass () const

Vector3	GetCOM () const

Vector3	GetCOM (const Config &q)

Matrix3	GetTotalInertia () const

void	GetCOMJacobian (Matrix &Jc) const

void	GetCOMHessian (Matrix &Hx, Matrix &Hy, Matrix &Hz) const

void	GetGravityTorques (const Vector3 &g0, Vector &G) const

Real	GetGravityPotentialEnergy (const Vector3 &g0, Real refHeight=Zero) const

void	GetWorldPosition (const Vector3 &pi, int i, Vector3 &p) const
	in the following, pi is a point in the local frame of body i

const Matrix3 &	GetWorldRotation (int i) const

void	GetWorldRotation_Moment (int i, Vector3 &m) const

void	GetWorldVelocity (const Vector3 &pi, int i, const Vector &dq, Vector3 &dp) const
	gets the world velocity/angular velocity of pi, given dq/dt

void	GetWorldAngularVelocity (int i, const Vector &dq, Vector3 &omega) const

bool	GetWorldRotationDeriv (int i, int j, Matrix3 &dR) const
	derivative of Ri w.r.t. qj

bool	GetWorldRotationDeriv_Moment (int i, int j, Vector3 &dm) const

bool	GetWorldRotationDeriv_Moment (int i, int j, const Vector3 &m, Vector3 &dm) const
	same as above, but m s.t. Ri=e^[m] is specified

bool	GetJacobian (const Vector3 &pi, int i, int j, Vector3 &dw, Vector3 &dv) const
	gets the jacobian of pi w.r.t qj

bool	GetOrientationJacobian (int i, int j, Vector3 &dw) const

bool	GetPositionJacobian (const Vector3 &pi, int i, int j, Vector3 &dv) const

void	GetFullJacobian (const Vector3 &pi, int i, Matrix &J) const

void	GetPositionJacobian (const Vector3 &pi, int i, Matrix &J) const
	rows 3-5 of the above

void	GetWrenchTorques (const Vector3 &torque, const Vector3 &force, int i, Vector &F) const
	for a wrench w=(torque,force) on link i, returns joint torques F = J^t w

void	AddWrenchTorques (const Vector3 &torque, const Vector3 &force, int i, Vector &F) const

void	GetForceTorques (const Vector3 &f, const Vector3 &pi, int i, Vector &F) const
	for a force f at pi on link i, returns joint torques F = J^t f

void	AddForceTorques (const Vector3 &f, const Vector3 &pi, int i, Vector &F) const

bool	GetJacobianDeriv (const Vector3 &pm, int m, int i, int j, Vector3 &ddtheta, Vector3 &ddp) const

void	GetJacobianDeriv_Fast (const Vector3 &pm, int m, int i, int j, Vector3 &ddtheta, Vector3 &ddp) const
	assumes i,j<=m

void	GetJacobianDeriv (const Vector3 &pm, int m, Matrix Htheta[3], Matrix Hp[3]) const

void	GetPositionHessian (const Vector3 &pm, int m, Matrix *Hp[3]) const

void	GetDirectionalHessian (const Vector3 &pm, int m, const Vector3 &v, Matrix &Hpv) const

Real	PointDistanceBound (const Vector3 &pi, int i, const Config &q1, const Config &q2) const

Real	PointDistanceBound2 (const Vector3 &pi, int i, const Config &q1, const Config &q2)
	A closer upper bound than the previous. Overwrites robot's state.

Real	SphereDistanceBound (const Vector3 &ci, Real r, int i, const Config &q1, const Config &q2)

Public Member Functions inherited from Chain
bool	HasValidOrdering () const

bool	IsAncestor (int n, int p) const
	Returns true if p is an ancestor of n.

bool	IsDescendent (int n, int c) const
	Returns true if c is a descendant of n.

int	LCA (int a, int b) const
	Least common ancestor.

void	GetChildList (std::vector< std::vector< int > > &children) const
	Returns a vector where element i is a vectors of the children of link i.

void	GetAncestors (int k, std::vector< bool > &ancestors) const
	Returns a vector where element i is true if it is an ancestor of n.

void	GetDescendants (int k, std::vector< bool > &descendants) const
	Returns a vector where element i is true if it is an descendant of n.

Public Attributes
std::vector< RobotLink3D >	links

Config	q
	current configuration

Vector	qMin

Vector	qMax
	joint limits

Public Attributes inherited from Chain
std::vector< int >	parents
	Topologically sorted list of parents.

Additional Inherited Members
Public Types inherited from Chain
enum	{ NoParent = -1 }

Detailed Description

Class defining kinematics of a robot, and commonly used functions.

Defines a robot's kinematic model as an articulated set of links. The Chain superclass defines each link's parents. Note: links must be defined in topologically sorted order (parents before children) for many algorithms to work.

The current configuration is given by a Vector q. The current link frames are updated when UpdateFrames() is called, and are stored in links[i].T_World.

Note that the kinematic model is often used for temporary storage (i.e. in planners, simulators, etc.) so you should count on the state being changed. If you need to store state, copy out the current configuration.

Member Function Documentation

void RobotKinematics3D::GetFullJacobian	(	const Vector3 &	pi,
		int	i,
		Matrix &	J
	)		const

gets the jacobian matrix of pi w.r.t q row 0-2 are angular, 3-5 are translational

bool RobotKinematics3D::GetJacobianDeriv	(	const Vector3 &	pm,
		int	m,
		int	i,
		int	j,
		Vector3 &	ddtheta,
		Vector3 &	ddp
	)		const

In the following, the pseudo-hessian H[i,j] is d/dqj(dpm/dqi) for the points pm on link m (in local coordinates). It is a pseudo-hessian because the orientation components are not symmetric. The position components are a true hessian.

Referenced by GetJacobianDeriv_Fast().

Real RobotKinematics3D::PointDistanceBound	(	const Vector3 &	pi,
		int	i,
		const Config &	q1,
		const Config &	q2
	)		const

Upper bounds the distance traveled by the point (attached to link i's frame) when moving from q1 to q2 (in a linear interpolation).

Real RobotKinematics3D::SphereDistanceBound	(	const Vector3 &	ci,
		Real	r,
		int	i,
		const Config &	q1,
		const Config &	q2
	)

Upper bounds the distance traveled by a sphere attached to the local frame of i, centered at ci with radius r, when moving from q1 to q2 (in a linear interpolation). Uses algorithm 2.

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

RobotKinematics3D.h
RobotKinematics3D.cpp

Public Member Functions

Public Attributes

Additional Inherited Members

Detailed Description

Member Function Documentation