MocoExtendProblem: Interface Between OpenSim and MATLAB for Rapidly Developing Direct Collocation Goals in Moco 1.1.0
add custom Moco goals to existing matlab scripts
Public Member Functions | Private Member Functions | List of all members
MocoMarkerAccelerationGoal Class Reference

Goal that minimizes marker acceleration in a Moco optimization problem. More...

#include <MocoMarkerAccelerationGoal.h>

Inheritance diagram for MocoMarkerAccelerationGoal:
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Public Member Functions

void setMarkerName (std::string name)
 Set the name of the marker whose acceleration should be minimized.
 
void setMarkerName (std::string name)
 Set the name of the marker to track.
 
void setExponent (int ex)
 Set the exponent for the acceleration terms.
 
bool getExponent () const
 Get the current exponent value.
 
void setDivideByDisplacement (bool tf)
 Set whether to divide by displacement.
 
bool getDivideByDisplacement () const
 Get whether the goal is divided by displacement.
 
Constructors
 MocoMarkerAccelerationGoal ()
 Default constructor.
 
 MocoMarkerAccelerationGoal (std::string name)
 Constructor with name.
 
 MocoMarkerAccelerationGoal (std::string name, double weight)
 Constructor with name and weight.
 
 MocoMarkerAccelerationGoal ()
 Default constructor.
 
 MocoMarkerAccelerationGoal (std::string name)
 Constructor with name.
 
 MocoMarkerAccelerationGoal (std::string name, double weight)
 Constructor with name and weight.
 

Protected Member Functions

Required implementations of virtual methods
Mode getDefaultModeImpl () const override
 Get the default mode for this goal.
 
void initializeOnModelImpl (const Model &) const override
 Initialize the goal with the model.
 
void calcIntegrandImpl (const IntegrandInput &input, SimTK::Real &integrand) const override
 Calculate the integrand value for the cost function.
 
void calcGoalImpl (const GoalInput &input, SimTK::Vector &cost) const override
 Calculate the goal value.
 
Mode getDefaultModeImpl () const override
 Get the default mode for this goal.
 
void initializeOnModelImpl (const Model &) const override
 Initialize the goal with the model.
 
void calcIntegrandImpl (const IntegrandInput &input, SimTK::Real &integrand) const override
 Calculate the integrand value for the cost function.
 
void calcGoalImpl (const GoalInput &input, SimTK::Vector &cost) const override
 Calculate the goal value.
 

Private Member Functions

 OpenSim_DECLARE_CONCRETE_OBJECT (MocoMarkerAccelerationGoal, MocoGoal)
 
void constructProperties ()
 Initialize the goal's properties.
 
 OpenSim_DECLARE_CONCRETE_OBJECT (MocoMarkerAccelerationGoal, MocoGoal)
 
void constructProperties ()
 Initialize the goal's properties.
 
Properties
 OpenSim_DECLARE_PROPERTY (exponent, int, "The exponent applied to the output value in the integrand. " "The output can take on negative values in the integrand when the " "exponent is set to 1 (the default value). When the exponent is " "set to a value greater than 1, the absolute value function is " "applied to the output (before the exponent is applied), meaning " "that odd numbered exponents (greater than 1) do not take on " "negative values.")
 
 OpenSim_DECLARE_PROPERTY (marker_name, std::string, "The name of the marker for this goal")
 
 OpenSim_DECLARE_PROPERTY (divide_by_displacement, bool, "Divide by the model's displacement over the phase (default: " "false)")
 
 OpenSim_DECLARE_PROPERTY (exponent, int, "The exponent applied to the output value in the integrand. " "The output can take on negative values in the integrand when the " "exponent is set to 1 (the default value). When the exponent is " "set to a value greater than 1, the absolute value function is " "applied to the output (before the exponent is applied), meaning " "that odd numbered exponents (greater than 1) do not take on " "negative values.")
 
 OpenSim_DECLARE_PROPERTY (marker_name, std::string, "The name of the marker for this goal")
 

Private Attributes

Internal working variables
std::function< double(const double &)> m_power_function
 
SimTK::ReferencePtr< const Point > m_model_marker
 Reference to the marker in the model.
 

Detailed Description

Goal that minimizes marker acceleration in a Moco optimization problem.

Goal that minimizes the acceleration of a model marker.

This goal minimizes the absolute acceleration of a model marker summed over its x, y, and z components, integrated over the phase. The integrand is:

\[ |\ddot{p}|^p = (|\ddot{p}_x| + |\ddot{p}_y| + |\ddot{p}_z|)^p \]

where $ \ddot{p} $ is the marker acceleration and $ p $ is the exponent (default: 2).

This goal can be useful for:

  • Reducing rapid changes in marker motion
  • Smoothing marker trajectories
  • Minimizing jerk in marker paths
Note
The marker must exist in the model and its name must be specified using setMarkerName() before the goal can be used.

This goal minimizes the absolute acceleration of a specified model marker, integrated over the phase. The acceleration is computed as the sum of the squared accelerations in the x, y, and z directions.

This goal can be useful for:

  • Generating smoother marker trajectories
  • Reducing rapid changes in marker motion
  • Minimizing jerk in specific body segments
  • Improving motion naturalness

The goal requires specification of a marker name to track. The acceleration can be raised to a specified power using the exponent property, and can optionally be divided by the total displacement of the model during the phase to make the cost invariant to the distance traveled.

Constructor & Destructor Documentation

◆ MocoMarkerAccelerationGoal() [1/6]

MocoMarkerAccelerationGoal ( )
inline

Default constructor.

◆ MocoMarkerAccelerationGoal() [2/6]

MocoMarkerAccelerationGoal ( std::string name)
inline

Constructor with name.

Parameters
nameThe name of the goal

◆ MocoMarkerAccelerationGoal() [3/6]

MocoMarkerAccelerationGoal ( std::string name,
double weight )
inline

Constructor with name and weight.

Parameters
nameThe name of the goal
weightWeight for this goal term in the optimization

◆ MocoMarkerAccelerationGoal() [4/6]

MocoMarkerAccelerationGoal ( )
inline

Default constructor.

◆ MocoMarkerAccelerationGoal() [5/6]

MocoMarkerAccelerationGoal ( std::string name)
inline

Constructor with name.

Parameters
nameThe name of the goal

◆ MocoMarkerAccelerationGoal() [6/6]

MocoMarkerAccelerationGoal ( std::string name,
double weight )
inline

Constructor with name and weight.

Parameters
nameThe name of the goal
weightWeight for this goal term in the optimization

Member Function Documentation

◆ calcGoalImpl() [1/2]

void calcGoalImpl ( const GoalInput & input,
SimTK::Vector & cost ) const
overrideprotected

Calculate the goal value.

Parameters
inputInput data containing the integral
costVector to store the calculated cost

◆ calcGoalImpl() [2/2]

void calcGoalImpl ( const GoalInput & input,
SimTK::Vector & cost ) const
overrideprotected

Calculate the goal value.

Parameters
inputInput data containing the integral
costVector to store the calculated cost

◆ calcIntegrandImpl() [1/2]

void calcIntegrandImpl ( const IntegrandInput & input,
SimTK::Real & integrand ) const
overrideprotected

Calculate the integrand value for the cost function.

Parameters
inputInput data for the current state
integrandReference to store the calculated integrand value

◆ calcIntegrandImpl() [2/2]

void calcIntegrandImpl ( const IntegrandInput & input,
SimTK::Real & integrand ) const
overrideprotected

Calculate the integrand value for the cost function.

Parameters
inputInput data for the current state
integrandReference to store the calculated integrand value

◆ constructProperties() [1/2]

void constructProperties ( )
private

Initialize the goal's properties.

◆ constructProperties() [2/2]

void constructProperties ( )
private

Initialize the goal's properties.

◆ getDefaultModeImpl() [1/2]

Mode getDefaultModeImpl ( ) const
inlineoverrideprotected

Get the default mode for this goal.

◆ getDefaultModeImpl() [2/2]

Mode getDefaultModeImpl ( ) const
inlineoverrideprotected

Get the default mode for this goal.

◆ getDivideByDisplacement()

bool getDivideByDisplacement ( ) const
inline

Get whether the goal is divided by displacement.

Returns
True if divided by displacement, false otherwise

◆ getExponent()

bool getExponent ( ) const
inline

Get the current exponent value.

Returns
The exponent value

◆ initializeOnModelImpl() [1/2]

void initializeOnModelImpl ( const Model & model) const
overrideprotected

Initialize the goal with the model.

◆ initializeOnModelImpl() [2/2]

void initializeOnModelImpl ( const Model & ) const
overrideprotected

Initialize the goal with the model.

◆ OpenSim_DECLARE_CONCRETE_OBJECT() [1/2]

OpenSim_DECLARE_CONCRETE_OBJECT ( MocoMarkerAccelerationGoal ,
MocoGoal  )
private

◆ OpenSim_DECLARE_CONCRETE_OBJECT() [2/2]

OpenSim_DECLARE_CONCRETE_OBJECT ( MocoMarkerAccelerationGoal ,
MocoGoal  )
private

◆ OpenSim_DECLARE_PROPERTY() [1/5]

OpenSim_DECLARE_PROPERTY ( divide_by_displacement ,
bool ,
"Divide by the model's displacement over the phase (default: " "false)"  )
private

◆ OpenSim_DECLARE_PROPERTY() [2/5]

OpenSim_DECLARE_PROPERTY ( exponent ,
int ,
"The exponent applied to the output value in the integrand. " "The output can take on negative values in the integrand when the " "exponent is set to 1 (the default value). When the exponent is " "set to a value greater than 1,
the absolute value function is " "applied to the outputbefore the exponent is applied,
meaning " "that odd numbered exponents(greater than 1) do not take on " "negative values."  )
private

◆ OpenSim_DECLARE_PROPERTY() [3/5]

OpenSim_DECLARE_PROPERTY ( exponent ,
int ,
"The exponent applied to the output value in the integrand. " "The output can take on negative values in the integrand when the " "exponent is set to 1 (the default value). When the exponent is " "set to a value greater than 1,
the absolute value function is " "applied to the outputbefore the exponent is applied,
meaning " "that odd numbered exponents(greater than 1) do not take on " "negative values."  )
private

◆ OpenSim_DECLARE_PROPERTY() [4/5]

OpenSim_DECLARE_PROPERTY ( marker_name ,
std::string ,
"The name of the marker for this goal"  )
private

◆ OpenSim_DECLARE_PROPERTY() [5/5]

OpenSim_DECLARE_PROPERTY ( marker_name ,
std::string ,
"The name of the marker for this goal"  )
private

◆ setDivideByDisplacement()

void setDivideByDisplacement ( bool tf)
inline

Set whether to divide by displacement.

Parameters
tfTrue to divide by displacement, false otherwise
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◆ setExponent()

void setExponent ( int ex)
inline

Set the exponent for the acceleration terms.

Parameters
exThe exponent value

◆ setMarkerName() [1/2]

void setMarkerName ( std::string name)
inline

Set the name of the marker whose acceleration should be minimized.

Parameters
nameName of the marker in the model

◆ setMarkerName() [2/2]

void setMarkerName ( std::string name)
inline

Set the name of the marker to track.

Parameters
nameThe marker name

Member Data Documentation

◆ m_model_marker

SimTK::ReferencePtr< const Point > m_model_marker
mutableprivate

Reference to the marker in the model.

Reference to the model marker being tracked.

◆ m_power_function

std::function< double(const double &)> m_power_function
mutableprivate

Function to compute power of acceleration values

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