OpenSim::ActuatorForceTargetFast Class Reference

A Computed Muscle Control (CMC) optimization target for controlling dynamic systems whose actuators may be themselves governed by differential equations, meaning there may be non-linear behavior and delays in force production. More...

Inheritance diagram for OpenSim::ActuatorForceTargetFast:

Public Member Functions
virtual	~ActuatorForceTargetFast ()
	ActuatorForceTargetFast (SimTK::State &s, int aNX, CMC *aController)
bool	prepareToOptimize (SimTK::State &s, double *x) override
int	objectiveFunc (const SimTK::Vector &aF, bool new_coefficients, SimTK::Real &rP) const override
int	gradientFunc (const SimTK::Vector &x, bool new_coefficients, SimTK::Vector &gradient) const override
int	constraintFunc (const SimTK::Vector &x, bool new_coefficients, SimTK::Vector &constraints) const override
int	constraintJacobian (const SimTK::Vector &x, bool new_coefficients, SimTK::Matrix &jac) const override
CMC *	getController ()
Public Member Functions inherited from OpenSim::OptimizationTarget
	OptimizationTarget (int aNX=0)
void	setNumParameters (const int aNX)
void	setDX (double aVal)
void	setDX (int aIndex, double aVal)
double	getDX (int aIndex)
double *	getDXArray ()
void	validatePerturbationSize (double &aSize)
virtual void	printPerformance (double *x)
Public Member Functions inherited from SimTK::OptimizerSystem
	OptimizerSystem ()
	OptimizerSystem (int nParameters)
virtual	~OptimizerSystem ()
virtual int	hessian (const Vector &parameters, bool new_parameters, Vector &gradient) const
void	setNumParameters (const int nParameters)
void	setNumEqualityConstraints (const int n)
void	setNumInequalityConstraints (const int n)
void	setNumLinearEqualityConstraints (const int n)
void	setNumLinearInequalityConstraints (const int n)
void	setParameterLimits (const Vector &lower, const Vector &upper)
int	getNumParameters () const
int	getNumConstraints () const
int	getNumEqualityConstraints () const
int	getNumInequalityConstraints () const
int	getNumLinearEqualityConstraints () const
int	getNumNonlinearEqualityConstraints () const
int	getNumLinearInequalityConstraints () const
int	getNumNonlinearInequalityConstraints () const
bool	getHasLimits () const
void	getParameterLimits (Real **lower, Real **upper) const

Additional Inherited Members
Static Public Member Functions inherited from OpenSim::OptimizationTarget
static int	CentralDifferencesConstraint (const OptimizationTarget *aTarget, double *dx, const SimTK::Vector &x, SimTK::Matrix &jacobian)
static int	CentralDifferences (const OptimizationTarget *aTarget, double *dx, const SimTK::Vector &x, SimTK::Vector &dpdx)
static int	ForwardDifferences (const OptimizationTarget *aTarget, double *dx, const SimTK::Vector &x, SimTK::Vector &dpdx)
Static Public Attributes inherited from OpenSim::OptimizationTarget
static const double	SMALLDX
	Smallest allowable perturbation size for computing derivatives. More...
Protected Attributes inherited from OpenSim::OptimizationTarget
Array< double >	_dx
	Perturbation size for computing numerical derivatives. More...

Detailed Description

A Computed Muscle Control (CMC) optimization target for controlling dynamic systems whose actuators may be themselves governed by differential equations, meaning there may be non-linear behavior and delays in force production.

The performance criterion is the sum of actuator stresses squared. The desired accelerations are achieved by imposing a set of constraints. The desired accelerations are computed according to the Proportional Derivative (PD) control in order to drive the dynamic model toward a set of target kinematic trajectories.

Because the desired accelerations are achieved by imposing a set of linear hard constraints, this optimization target can fail if the desired accelerations cannot be achieved. To insure that the constraints can be achieved, a number of sufficiently strong actuators can be added to the model. Alternatively, one can use a different optimization target ActuatorForceTarget. The benefits of using the fast target are both speed and tracking accuracy.

Version

1.0

Author

Frank C. Anderson

Constructor & Destructor Documentation

~ActuatorForceTargetFast()

virtual OpenSim::ActuatorForceTargetFast::~ActuatorForceTargetFast ( )

virtual

ActuatorForceTargetFast()

OpenSim::ActuatorForceTargetFast::ActuatorForceTargetFast	(	SimTK::State &	s,
		int	aNX,
		CMC *	aController
	)

Member Function Documentation

constraintFunc()

int OpenSim::ActuatorForceTargetFast::constraintFunc ( const SimTK::Vector &  x, bool  new_coefficients, SimTK::Vector &  constraints  ) const

overridevirtual

Reimplemented from SimTK::OptimizerSystem.

constraintJacobian()

int OpenSim::ActuatorForceTargetFast::constraintJacobian ( const SimTK::Vector &  x, bool  new_coefficients, SimTK::Matrix &  jac  ) const

overridevirtual

Reimplemented from SimTK::OptimizerSystem.

getController()

CMC* OpenSim::ActuatorForceTargetFast::getController ( )

inline

gradientFunc()

int OpenSim::ActuatorForceTargetFast::gradientFunc ( const SimTK::Vector &  x, bool  new_coefficients, SimTK::Vector &  gradient  ) const

overridevirtual

Reimplemented from SimTK::OptimizerSystem.

objectiveFunc()

int OpenSim::ActuatorForceTargetFast::objectiveFunc ( const SimTK::Vector &  aF, bool  new_coefficients, SimTK::Real &  rP  ) const

overridevirtual

Reimplemented from SimTK::OptimizerSystem.

prepareToOptimize()

bool OpenSim::ActuatorForceTargetFast::prepareToOptimize ( SimTK::State &  s, double *  x  )

overridevirtual

Reimplemented from OpenSim::OptimizationTarget.

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

• OpenSim/Tools/ActuatorForceTargetFast.h