OpenSim::InverseKinematicsSolver Class Reference
Solve for the coordinates (degrees-of-freedom) of the model that satisfy the set of constraints imposed on the model as well as set of desired coordinate values. More...
#include <InverseKinematicsSolver.h>
Public Member Functions | |
| virtual | ~InverseKinematicsSolver () |
| InverseKinematicsSolver (const Model &model, MarkersReference &markersReference, SimTK::Array_< CoordinateReference > &coordinateReferences, double constraintWeight=SimTK::Infinity) | |
| An implementation of the InverseKinematicsSolver. | |
| void | updateMarkerWeight (const std::string &markerName, double value) |
| Assemble a model configuration that meets the InverseKinematics conditions (desired values and constraints) starting from an initial state that does not have to satisfy the constraints. | |
| void | updateMarkerWeight (int markerIndex, double value) |
| Update a marker's weight by its index. | |
| void | updateMarkerWeights (const SimTK::Array_< double > &weights) |
| Update all markers weights by order in the markersRerence passed in to construct the solver. | |
| SimTK::Vec3 | computeCurrentMarkerLocation (const std::string &markerName) |
| Compute and return the spatial location of a marker in ground. | |
| SimTK::Vec3 | computeCurrentMarkerLocation (int markerIndex) |
| void | computeCurrentMarkerLocations (SimTK::Array_< SimTK::Vec3 > &markerLocations) |
| Compute and return the spatial locations of all markers in ground. | |
| double | computeCurrentMarkerError (const std::string &markerName) |
| Compute and return the distance error between model marker and observation. | |
| double | computeCurrentMarkerError (int markerIndex) |
| void | computeCurrentMarkerErrors (SimTK::Array_< double > &markerErrors) |
| Compute and return the distance errors between all model markers and their observations. | |
| double | computeCurrentSquaredMarkerError (const std::string &markerName) |
| Compute and return the squared-distance error between model marker and observation. | |
| double | computeCurrentSquaredMarkerError (int markerIndex) |
| void | computeCurrentSquaredMarkerErrors (SimTK::Array_< double > &markerErrors) |
| Compute and return the distance errors between all model marker and observations. | |
Protected Member Functions | |
| virtual void | setupGoals (SimTK::State &s) |
| Internal method to convert the CoordinateReferences into goals of the assembly solver. | |
| virtual void | updateGoals (const SimTK::State &s) |
| Internal method to update the time, reference values and/or their weights that define the goals, based on the passed in state. | |
Protected Attributes | |
| MarkersReference & | _markersReference |
| SimTK::Markers * | _markerAssemblyCondition |
Detailed Description
Solve for the coordinates (degrees-of-freedom) of the model that satisfy the set of constraints imposed on the model as well as set of desired coordinate values.
The InverseKinematics provides the option to convert the problem to an approximate one where the constraint violations are treated as penalties to be minimized rather than strictly enforced. This can speed up the time solution and can be used to seed the constrained problem near to a solution.
The InverseKinematics objective: min J = sum(Wm*(m_i-md_i)^T*(m_i-md_i)) + sum(Wq_i*(q_i-qd_i)^2)) + [Wc*sum(c_err)^2] where m_i and md_i are the model and desired marker coordinates (Vec3) iff Wc == Infinity, second term is not included, but A is subject to the constraint equations: G(q)-Go = 0
When the model (and the number of goals) is guaranteed not to change and the the initial state is close to the InverseKinematics solution (from initial assemble(), then track() is a efficient method for updating the configuration to track the small change to the desired coorindate value.
See SimTK::Assembler for more algorithmic details of the underlying solver.
- Version:
- 1.0
Constructor & Destructor Documentation
| virtual OpenSim::InverseKinematicsSolver::~InverseKinematicsSolver | ( | ) | [inline, virtual] |
| OpenSim::InverseKinematicsSolver::InverseKinematicsSolver | ( | const Model & | model, | |
| MarkersReference & | markersReference, | |||
| SimTK::Array_< CoordinateReference > & | coordinateReferences, | |||
| double | constraintWeight = SimTK::Infinity | |||
| ) |
An implementation of the InverseKinematicsSolver.
- Parameters:
-
model to assemble
Member Function Documentation
| double OpenSim::InverseKinematicsSolver::computeCurrentMarkerError | ( | int | markerIndex | ) |
| double OpenSim::InverseKinematicsSolver::computeCurrentMarkerError | ( | const std::string & | markerName | ) |
Compute and return the distance error between model marker and observation.
| void OpenSim::InverseKinematicsSolver::computeCurrentMarkerErrors | ( | SimTK::Array_< double > & | markerErrors | ) |
Compute and return the distance errors between all model markers and their observations.
| SimTK::Vec3 OpenSim::InverseKinematicsSolver::computeCurrentMarkerLocation | ( | int | markerIndex | ) |
| SimTK::Vec3 OpenSim::InverseKinematicsSolver::computeCurrentMarkerLocation | ( | const std::string & | markerName | ) |
Compute and return the spatial location of a marker in ground.
| void OpenSim::InverseKinematicsSolver::computeCurrentMarkerLocations | ( | SimTK::Array_< SimTK::Vec3 > & | markerLocations | ) |
Compute and return the spatial locations of all markers in ground.
| double OpenSim::InverseKinematicsSolver::computeCurrentSquaredMarkerError | ( | int | markerIndex | ) |
| double OpenSim::InverseKinematicsSolver::computeCurrentSquaredMarkerError | ( | const std::string & | markerName | ) |
Compute and return the squared-distance error between model marker and observation.
This is cheaper than calling the error and squaring it, since distance from norm-2
| void OpenSim::InverseKinematicsSolver::computeCurrentSquaredMarkerErrors | ( | SimTK::Array_< double > & | markerErrors | ) |
Compute and return the distance errors between all model marker and observations.
| void OpenSim::InverseKinematicsSolver::setupGoals | ( | SimTK::State & | s | ) | [protected, virtual] |
Internal method to convert the CoordinateReferences into goals of the assembly solver.
Internal method to convert the MarkerReferences into additional goals of the of the base assembly solver, that is going to do the assembly.
Subclasses, can add oveeride to include other goals such as point of interest matching (Marker tracking). This method is automatically called by assemble.
Reimplemented from OpenSim::AssemblySolver.
| void OpenSim::InverseKinematicsSolver::updateGoals | ( | const SimTK::State & | s | ) | [protected, virtual] |
Internal method to update the time, reference values and/or their weights that define the goals, based on the passed in state.
Internal method to update the time, reference values and/or their weights based on the state.
Reimplemented from OpenSim::AssemblySolver.
| void OpenSim::InverseKinematicsSolver::updateMarkerWeight | ( | int | markerIndex, | |
| double | value | |||
| ) |
Update a marker's weight by its index.
| void OpenSim::InverseKinematicsSolver::updateMarkerWeight | ( | const std::string & | markerName, | |
| double | value | |||
| ) |
Assemble a model configuration that meets the InverseKinematics conditions (desired values and constraints) starting from an initial state that does not have to satisfy the constraints.
Change the weighting of a marker to take affect when assemble or track is called next.
Obtain a model configuration that meets the InverseKinematics conditions (desired values and constraints) given a state that satisfies or is close to satisfying the constraints. Note there can be no change in the number of constrainst or desired coordinates. Desired coordinate values can and should be updated between repeated calls to track a desired trajectory of coordinate values. Change the weighting of a marker to take affect when assemble or track is called next. Update a marker's weight by name.
Update a marker's weight by name.
| void OpenSim::InverseKinematicsSolver::updateMarkerWeights | ( | const SimTK::Array_< double > & | weights | ) |
Update all markers weights by order in the markersRerence passed in to construct the solver.
Update all markers weights by order in the markersReference passed in to construct the solver.
Member Data Documentation
SimTK::Markers* OpenSim::InverseKinematicsSolver::_markerAssemblyCondition [protected] |
The documentation for this class was generated from the following files:
- OpenSim/Simulation/InverseKinematicsSolver.h
- OpenSim/Simulation/InverseKinematicsSolver.cpp
