RobWorkProject

A Jacobian based iterative inverse kinematics algorithm for devices with multiple end effectors. More...
#include <JacobianIKSolverM.hpp>
Inherits IterativeMultiIK.
Public Types  
enum  JacobianSolverType { Transpose, SVD, DLS, SDLS } 
the type of Jacobian solver  
Public Types inherited from IterativeMultiIK  
typedef rw::common::Ptr< IterativeMultiIK >  Ptr 
smart pointer type to this class  
Public Member Functions  
JacobianIKSolverM (const models::TreeDevice *device, const kinematics::State &state)  
Constructs JacobianIKSolverM for TreeDevice. Uses the default end effectors of the TreeDevice.  
JacobianIKSolverM (const models::JointDevice *device, const std::vector< kinematics::Frame *> &foi, const kinematics::State &state)  
Constructs JacobianIKSolverM for a JointDevice(SerialDevice and TreeDevice). It does not use the default end effectors. A list of interest frames are given instead.  
virtual  ~JacobianIKSolverM () 
destructor  
void  setReturnBestFit (bool returnBestFit) 
configures the iterative solver to return the best fit found, even though error criteria was not met. More...  
void  setClampToBounds (bool enableClamping) 
enables clamping of the solution such that solution always is within joint limits. More...  
void  setEnableInterpolation (bool enableInterpolation) 
the solver may fail or be very slow if the the solution is too far from the initial configuration. This function enables the use of via points generated using an interpolation from initial end effector configuration to the goal target. More...  
void  setSolverType (JacobianSolverType type) 
set the type of solver to use for stepping toward a solution More...  
std::vector< math::Q >  solve (const std::vector< math::Transform3D<> > &baseTend, const kinematics::State &state) const 
Calculates the inverse kinematics. More...  
bool  solveLocal (const std::vector< rw::math::Transform3D<> > &bTed, std::vector< double > &maxError, kinematics::State &state, int maxIter, bool untilSmallChange=false) const 
performs a local search toward the the target bTed. No via points are generated to support the convergence and robustness. More...  
void  setMaxLocalStep (double qlength, double plength) 
sets the maximal step length that is allowed on the local search towards the solution. More...  
Public Member Functions inherited from IterativeMultiIK  
virtual  ~IterativeMultiIK () 
Destructor.  
virtual void  setMaxError (const std::vector< double > &maxError) 
Sets the maximal error for a solution. More...  
virtual std::vector< 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::common::PropertyMap &  getProperties () 
Returns the PropertyMap. More...  
virtual const rw::common::PropertyMap &  getProperties () const 
Returns the PropertyMap return Reference to the PropertyMap.  
Additional Inherited Members  
Protected Member Functions inherited from IterativeMultiIK  
IterativeMultiIK (size_t nrOfEndEff)  
Constructor.  
A Jacobian based iterative inverse kinematics algorithm for devices with multiple end effectors.
This algorithm does not implicitly handle joint limits, however it is possible to force the solution within joint limits using clamping in each iterative step. If joint clamping is not enabled then this algorithm might contain joint values that are out of bounds.
The method uses an NewtonRaphson iterative approach and is based on using the inverse of the device Jacobian to compute each local solution in each iteration. Several methods for calculating/approximating the inverse Jacobian are available, where the SVD method currently is the most stable, see the JacobianSolverType option for additional options.
The method is based on the following approximation:
Where is calculated like:

inline 
enables clamping of the solution such that solution always is within joint limits.
enableClamping  [in] true to enable clamping, false otherwise 

inline 
the solver may fail or be very slow if the the solution is too far from the initial configuration. This function enables the use of via points generated using an interpolation from initial end effector configuration to the goal target.
enableInterpolation  [in] set true to enable interpolation, false otherwise 
void setMaxLocalStep  (  double  qlength, 
double  plength  
) 
sets the maximal step length that is allowed on the local search towards the solution.
qlength  [in] maximal step length in quaternion 
plength  [in] maximal step length in position 

inline 
configures the iterative solver to return the best fit found, even though error criteria was not met.
returnBestFit  [in] set to true if you want best fit returned. 

inline 
set the type of solver to use for stepping toward a solution
type  [in] the type of Jacobian solver 

virtual 
Calculates the inverse kinematics.
Given a desired 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) )
baseTend  [in] Desired base to end transformation 
state  [in] State of the device from which to start the iterations 
Implements IterativeMultiIK.
bool solveLocal  (  const std::vector< rw::math::Transform3D<> > &  bTed, 
std::vector< double > &  maxError,  
kinematics::State &  state,  
int  maxIter,  
bool  untilSmallChange = false 

)  const 
performs a local search toward the the target bTed. No via points are generated to support the convergence and robustness.
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 
untilSmallChange  [in] if true the error difference between two successive iterations need to be smaller than maxError. If false then the error of a iteration need to be smaller than maxError. 