CCDSolver Class Reference

This inverse kinematics method is a heuristic search technique called the Cyclic-Coordinate Descent method. The method attempts to minimize position and orientation errors by varying individual joints at a time. More...

#include <CCDSolver.hpp>

Inherits IterativeIK.

Public Member Functions
	CCDSolver (const rw::models::SerialDevice *device, const rw::kinematics::State &state)
	Constructor.
	CCDSolver (const rw::core::Ptr< const rw::models::SerialDevice > device, const rw::kinematics::State &state)
	Construct new CCSSolver. More...
void	setMaxLocalStep (double quatlength)
	Sets the maximal size of a local step. More...
std::vector< rw::math::Q >	solve (const rw::math::Transform3D< double > &baseTend, const rw::kinematics::State &state) const
	Calculates the inverse kinematics. More...
bool	solveLocal (const rw::math::Transform3D< double > &bTed, double maxError, rw::kinematics::State &state, int maxIter) const
	performs a local search toward the the target bTed. No via points are generated to support the convergence and robustness. More...
virtual void	setCheckJointLimits (bool check)
	Specifies whether to check joint limits before returning a solution. More...
virtual rw::core::Ptr< const rw::kinematics::Frame >	getTCP () const
	Returns the Tool Center Point (TCP) used when solving the IK problem. More...
Public Member Functions inherited from IterativeIK
virtual	~IterativeIK ()
	Destructor.
virtual void	setMaxError (double maxError)
	Sets the maximal error for a solution. More...
virtual double	getMaxError () const
	Returns the maximal error for a solution. More...
virtual void	setMaxIterations (int maxIterations)
	Sets the maximal number of iterations allowed. More...
virtual int	getMaxIterations () const
	Returns the maximal number of iterations.
virtual rw::core::PropertyMap &	getProperties ()
	Returns the PropertyMap. More...
virtual const rw::core::PropertyMap &	getProperties () const
	Returns the PropertyMap return Reference to the PropertyMap.
Public Member Functions inherited from InvKinSolver
virtual	~InvKinSolver ()
	destructor

Additional Inherited Members
Public Types inherited from IterativeIK
typedef rw::core::Ptr< IterativeIK >	Ptr
	smart pointer type to this class
typedef rw::core::Ptr< const IterativeIK >	CPtr
	smart pointer type to this const class
Public Types inherited from InvKinSolver
typedef rw::core::Ptr< InvKinSolver >	Ptr
	smart pointer type to this class
typedef rw::core::Ptr< const InvKinSolver >	CPtr
	smart pointer type to this const class
Static Public Member Functions inherited from IterativeIK
static IterativeIK::Ptr	makeDefault (rw::core::Ptr< rw::models::Device > device, const rw::kinematics::State &state)
	Default iterative inverse kinematics solver for a device and state. More...
Protected Member Functions inherited from IterativeIK
	IterativeIK ()
	Constructor.

Detailed Description

This inverse kinematics method is a heuristic search technique called the Cyclic-Coordinate Descent method. The method attempts to minimize position and orientation errors by varying individual joints at a time.

Notice that the CCDSolver only work on devices with 1-dof joints.

Constructor & Destructor Documentation

CCDSolver()

CCDSolver	(	const rw::core::Ptr< const rw::models::SerialDevice >	device,
		const rw::kinematics::State &	state
	)

Construct new CCSSolver.

Note

The dimensions will be automatically extracted from the device, using an arbitrary state.

Parameters

device	[in] the device.
state	[in] the state to use to extract dimensions.

Exceptions

rw::core::Exception

if device is not castable to SerialDevice

Member Function Documentation

getTCP()

virtual rw::core::Ptr<const rw::kinematics::Frame> getTCP ( ) const

virtual

Returns the Tool Center Point (TCP) used when solving the IK problem.

Returns

The TCP Frame used when solving the IK.

Implements InvKinSolver.

setCheckJointLimits()

virtual void setCheckJointLimits ( bool  check )

inlinevirtual

Specifies whether to check joint limits before returning a solution.

Parameters

check

[in] If true the method should perform a check that joints are within bounds.

Implements InvKinSolver.

setMaxLocalStep()

void setMaxLocalStep

(

double

quatlength

)

Sets the maximal size of a local step.

Parameters

quatlength

[in] Maximal length for quartenion

solve()

std::vector<rw::math::Q> solve ( const rw::math::Transform3D< double > &  baseTend, const rw::kinematics::State &  state  ) const

virtual

Calculates the inverse kinematics.

Given a desired \(\robabx{}{desired}{\mathbf{T}}\) and the current state, the method solves the inverse kinematics problem.

If the algorithm is able to identify multiple solutions (e.g. elbow up and down) it will return all of these. Before returning a solution, they may be checked to be within the bounds of the configuration space. (See setCheckJointLimits(bool) )

Parameters

baseTend	[in] Desired base to end transformation \( \robabx{}{desired}{\mathbf{T}}\)
state	[in] State of the device from which to start the iterations

Returns

List of solutions. Notice that the list may be empty.

Note

The targets baseTend must be defined relative to the base of the robot/device.

Example:
CCDAlgorithm r;
r.inverseKinematics(device, Ttarget);

Implements InvKinSolver.

solveLocal()

bool solveLocal	(	const rw::math::Transform3D< double > &	bTed,
		double	maxError,
		rw::kinematics::State &	state,
		int	maxIter
	)		const

performs a local search toward the the target bTed. No via points are generated to support the convergence and robustness.

Parameters

bTed	[in] the target end pose
maxError	[in] the maximal allowed error
state	[in/out] the starting position for the search. The end position will also be saved in this state.
maxIter	[in] max number of iterations

Returns

true if error is below max error

Note

the result will be saved in state

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

• CCDSolver.hpp