Namespace for algorithms related to solving the inverse kinematics. More...

Classes
class	GlobalIKBase

class	GlobalIKExtensive
	Finds all solutions to the Global IK. More...

class	GlobalIKSemiBreadth
	Expands all nets until a resolution has been reached, then search only for a single solution. More...

struct	GraphNode

struct	Solution

Typedefs
using	SolutionSet = std::vector<Solution>
	Return type of the global inverse kinematics solvers.

Functions
bool	operator< (const GraphNode &left, const GraphNode &right)

SolutionSet	solveGlobalIK (KBM::Models::KBM_ptr kbm, const Vector &lower, const Vector &upper, Real resolution=M_PI/90.0f)
	Algorithm to find the global solution to the inverse kinematics based on the KBM structure.

SolutionSet	solveGlobalIK (Models::KBM_ptr kbm, const Vector &target, Real resolution)

void	solveGlobalIK (unsigned int recursion, int side, SolutionSet &solutionSet, Models::KBM_ptr kbm, const Vector &lower, const Vector &upper, Real resolution, Vector spreadAngles, Vector center)

Detailed Description

Namespace for algorithms related to solving the inverse kinematics.

Typedef Documentation

◆ SolutionSet

using SolutionSet = std::vector<Solution>

Return type of the global inverse kinematics solvers.

Function Documentation

◆ operator<()

bool operator<	(	const GraphNode &	left,
		const GraphNode &	right )

◆ solveGlobalIK() [1/3]

SolutionSet solveGlobalIK	(	KBM::Models::KBM_ptr	kbm,
		const Vector &	lower,
		const Vector &	upper,
		Real	resolution = M_PI/90.0f )

Algorithm to find the global solution to the inverse kinematics based on the KBM structure.

Work in progress.

Parameters

kbm	The already learned KBM representation of a kinematics.
lower	The lower bound of the interval in Cartesian space.
upper	The upper bound of the interval in Cartesian space. Lower and upper bounds should be a target destination plus a desired tolerance, but can be chosen with equal values.
resolution	The granularity of the found solutions (defaults to $2^\circ$ ).

Returns: The algorithm returns a list of joint angle intervals (the size is specified by the resolution parameters).

This algorithm solves the inverse kinematics globally and numerically by using an interval based version of the forward kinemtatics

$f(\alpha_1, \beta_1,\ldots,\alpha_n,\beta_n) = ([a_x, \ldots, b_x],[a_y,\ldots,b_y],[a_z,\ldots,b_z]).$

which can be subdivided easily because of the linearisation emerging from the KBM model. This means that if there exist more than a single solution, a list of intervals that probably contain a solution. Specifically, this means that the target position lies within the bounding box of the control net of the subdivised kbm. If a sufficient amount of steps has been performed, the solution is garantueed to lie at least close to the desired target. The number of steps can be regulated by the resolution parameter (i.e., $n_{steps}=\log_2\frac{\alpha_{spread}}{\alpha_{resolution}}$ ). An interval-based version of this algorithm exists to define this distance in Cartesian space.

Subdivision in angular space

◆ solveGlobalIK() [2/3]

SolutionSet solveGlobalIK	(	Models::KBM_ptr	kbm,
		const Vector &	target,
		Real	resolution )

◆ solveGlobalIK() [3/3]

void solveGlobalIK	(	unsigned int	recursion,
		int	side,
		SolutionSet &	solutionSet,
		Models::KBM_ptr	kbm,
		const Vector &	lower,
		const Vector &	upper,
		Real	resolution,
		Vector	spreadAngles,
		Vector	center )

Classes

Typedefs

Functions