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)

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

override

constraintJacobian()

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

override

getController()

CMC* OpenSim::ActuatorForceTargetFast::getController ( )

inline

gradientFunc()

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

override

objectiveFunc()

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

override

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