Model Class Reference

The abstract class describes the basics for a musculoskeletal model. More...

Inheritance diagram for Model:

Public Member Functions
function	extractControl (in obj, in type, in controlname)
	Function to obtain index of contol with a specific type (and name)
function	extractState (in obj, in type, in statename)
	Function to obtain index of state with a specific type (and name)
function	getCoP (in obj, in grf)
	Function to calculate the center of pressure.
virtual	getDynamics (in obj, in x, in xdot, in u)
	Abstract function to compute implicit differential equation for the model.
function	getErate_bhargava (in obj, in F_ce, in stim, in act, in l_ce, in v_ce, in t_stim)
	Model function to calculate the energy rate of a single time step using Bhargava et al.
function	getErate_Houdijk (in obj, in F_ce, in act, in l_ce, in v_ce)
	Model function to calculate the energy rate of a single time.
function	getErate_Lichtwark (in obj, in F_ce, in act, in l_ce, in v_ce, in t_stim)
	Model function to calculate the energy rate of a single time step using a continuous version of Lichtwark & Wilson's model.
function	getErate_margaria (in obj, in F_ce, in v_ce)
	Model function to calculate the energy rate of a single time step using Margaria's model.
function	getErate_Minetti (in obj, in act, in v_ce)
	Model function to calculate the energy rate of a single time.
function	getErate_uchida (in obj, in F_ce, in stim, in act, in l_ce, in v_ce)
	Model function to calculate the energy rate of a single time.
function	getErate_Umberger (in obj, in F_ce, in stim, in act, in l_ce, in v_ce)
	Model function to calculate the energy rate of a single time step with Umberger et al.
function	getEratec_bhargava (in obj, in F_ce, in stim, in act, in l_ce, in v_ce, in dFdx, in dFdxdot, in epsilon)
	Model function to calculate the energy rate of a single time step using a continuous version of Bhargava et al.
function	getEratec_Houdijk (in obj, in F_ce, in act, in l_ce, in v_ce, in dFdx, in dFdxdot, in epsilon)
	Model function to calculate the energy rate of a single time step using a continuous version of Houdijk et al.
function	getEratec_Lichtwark (in obj, in F_ce, in act, in l_ce, in v_ce, in dFdx, in dFdxdot, in epsilon)
	Model function to calculate the energy rate of a single time step using a continuous version of Lichtwark & Wilson's model.
function	getEratec_margaria (in obj, in F_ce, in v_ce, in dFdx, in dFdxdot, in epsilon)
	Model function to calculate the energy rate of a single time step using a continuous version of Margaria's model.
function	getEratec_Minetti (in obj, in act, in v_ce)
	Model function to calculate the energy rate of a single time step using Minetti's model.
function	getEratec_umberger (in obj, in F_ce, in stim, in act, in l_ce, in v_ce, in dFdx, in dFdxdot, in epsilon)
	Model function to calculate the energy rate of a single time step with the continuous version of Umberger et al.
virtual	getGRF (in obj, in x)
	Abstract function returning the ground reaction forces for the system in state x.
virtual	getJointmoments (in obj, in x, in u)
	Abstract function returns joint moments, for the system in state x.
function	getMetabolicRate_pernode (in obj, in x, in xdot, in u, in t_stim, in name, in getCont, in epsilon, in exponent)
	Model function to calculate metabolic cost of a movement.
virtual	getMuscleCEforces (in obj, in x, in xdot)
	Abstract function returning muscle forces of CE for the system in state x.
virtual	getMuscleCEpower (in obj, in x, in xdot)
	Abstract function returns power generated by muscle contractile elements, for the system in state x.
virtual	getMuscleforces (in obj, in x)
	Abstract function returning muscle forces for the system in state x.
function	setbodymass (in obj, in bodymass)
	Function to set body mass, does not influence the.
function	setMuscles (in obj, in muscles)
	Function to set the muscles table.
function	setSegmentMass (in obj, in segmentName, in segmentMass)
	Function to set segment mass.
function	setSegments (in obj, in segmentTable)
	Function to set segment Table.
virtual	showStick (in obj, in x)
	Abstract function to show model as stick figure.
virtual	simuAccGyro (in obj, in data, in q, in qd, in qdd)
	Abstract function to simulate acceleration and gyroscope signals.

Public Attributes
Property	CPs
	Table: Contact points.
Property	dofs
	Table: Degrees of freedom (Range of Dofs should not be changed here.
Property	drag_coefficient
	Double: Air drag coefficient in N/(m/s)^2 (default: 0.2128)
Property	gravity
	Double array: Gravity vector in m/(s^2)
Constant Property	GRFNAMES = {'rightFx', 'rightFy', 'rightFz', 'rightMx', 'rightMy', 'rightMz', 'leftFx', 'leftFy', 'leftFz', 'leftMx', 'leftMy', 'leftMz' }
	Cell array with string: Gives the names for the GRF vector returned by getGRF()
Property	joints
	Table: Joints.
Property	mExtraScaleFactor
	Double: Scale factor for extra torques in Nm (default: 100 since we used this in previous simulations.
Property	muscles
	Table: Muscles.
Property	torques
	Table: Torque actuators.
Property	wind_speed
	Double: Wind speed in direction of +X in m/s (default: 0)

Protected Member Functions
virtual	initMex (in obj)
	Abstract function to initialize model mex file.
virtual	initModel (in obj, in vargin)
	Abstract function to initialize with default parameters.
virtual	update_constraints (in obj)
	Abstract function defining the table Model.constraints.
virtual	update_controls (in obj)
	Abstract function defining the table Model.controls.
function	update_idxControls (in obj)
	Function defining Model.hidxControls.
function	update_idxForward (in obj)
	Function defining Model.idxForward.
function	update_idxForwardAll (in obj)
	Function defining Model.idxForwardAll.
function	update_idxSideward (in obj)
	Function defining Model.idxSideward.
function	update_idxSidewardAll (in obj)
	Function defining Model.idxSidewardAll.
function	update_idxStates (in obj)
	Function defining Model.hidxStates.
virtual	update_idxSymmetry (in obj)
	Abstract function defining Model.idxSymmetry.
function	update_idxTorqueDof (in obj)
	Function defining Model.idxTorqueDof.
function	update_idxUpward (in obj)
	Function defining Model.idxUpward.
virtual	update_mexParameter (in obj, in src, in evnt)
	Abstract function performed to update the parameter of the mex and the tables.
virtual	update_states (in obj)
	Abstract function defining the table Model.states.

Protected Attributes
Property	constraints
	Table: Information on constraints implemented in the mex and here.
Property	controls
	Table: Information on controls of the model.
Property	idxForward
	Double array: Indices for forward translation.
Property	idxForwardAll
	Double array: Indices for forward translation, speed, position of contact points and force at contact points.
Property	idxSideward
	Double array: Indices for sideward translation.
Property	idxSidewardAll
	Double array: Indices for sideward translation, speed, position of contact points and force at contact points.
Property	idxSymmetry
	Struct: Double arrays with indices for symmetry to map right to left.
Property	idxTorqueDof
	Double array: Indices of dofs of torque actuators.
Property	idxUpward
	Double array: Indices for upward translation.
Property	init
	Double: Showing if the mex model is initialized.
Property	nConstraints
	Double: Number of constraints (height of Model.constraints)
Property	nControls
	Double: Number of controls (height of Model.controls)
Property	nCPs
	Double: Number of contact points (height of Model.CPs)
Property	nDofs
	Double: Number of degree of freedoms (height of Model.dofs)
Property	nJoints
	Double: Number of joints (height of Model.joints)
Property	nMus
	Double: Number of muscles (height of Model.muscles)
Property	nSegments
	Double: Number of segments (height of Model.segments)
Property	nStates
	Double: Number of states (height of Model.states)
Property	nTor
	Double: Number of torque actuators (height of Model.torques)
Property	segments
	Table: Segments (Segment properties should not be changed)
Property	states
	Table: Information on states of the model.

Detailed Description

The abstract class describes the basics for a musculoskeletal model.

Todo:

We should set init = 0 as soon as we are loading an other model. This should be also done for all models which are saved within an other object (e.g. problem.model). Furthermore, we should check init == 1 each time before calling the mex.

Member Function Documentation

extractControl()

function extractControl	(	in	obj,
		in	type,
		in	controlname
	)

Function to obtain index of contol with a specific type (and name)

Parameters

obj	Model class object
type	String: Type of the control
controlname	(optional) String or cell array of strings: Name of the control

Return values

iControl

Double array: Indices in Model.controls matching type (and name)

extractState()

function extractState	(	in	obj,
		in	type,
		in	statename
	)

Function to obtain index of state with a specific type (and name)

Parameters

obj	Model class object
type	String: Type of the state
statename	(optional) String or cell array of strings: Name of the state

Return values

iState

Double array: Indices in Model.states matching type (and name)

getCoP()

function getCoP	(	in	obj,
		in	grf
	)

Function to calculate the center of pressure.

It solves the center of pressure (COP) coordinates from: COP x F + Ty = M, where COP is a point in the XZ plane and Ty is the "free moment" on the Y axis. expand the equation:

1. COPy * Fz - COPz * Fy + 0 = Mx
2. COPz * Fx - COPx * Fz + Ty = My
3. COPx * Fy - COPy * Fx + 0 = Mz

Use COPy = 0, to get COPx = Mz / Fy and COPz = -Mx / Fy

For 2D, COPz will be 0.

Parameters

obj	Model class object
grf	Double vector: Ground contact vector containing Fx, Fy, Fz, Mx, My, Mz (right), and Fx, Fy, Fz, Mx, My, Mz (left) (12)

Return values

CoP_r	Double vector: Center of pressure in x, y and z direction for right foot (3)
CoP_l	Double vector: Center of pressure in x, y and z direction for left foot (3)

getDynamics()

virtual getDynamics ( in  obj, in  x, in  xdot, in  u  )

virtual

Abstract function to compute implicit differential equation for the model.

Reimplemented in Gait2d_osim, Gait2dc, and Gait3d.

getErate_bhargava()

function getErate_bhargava	(	in	obj,
		in	F_ce,
		in	stim,
		in	act,
		in	l_ce,
		in	v_ce,
		in	t_stim
	)

Model function to calculate the energy rate of a single time step using Bhargava et al.

's model

Function to calculate the energy rate at a single time step using a continuous version of Bhargava et al.'s model. Model paper: Bhargava et al., J Biomech, 2004

Inputs are muscle states of the specific muscle that is considered.

Parameters

obj	Model object
F_ce	Force in the contractile element
stim	Stimulation of the muscle (between 0 and 1)
act	Activation level of the muscle (between 0 and 1)
l_ce	Normalized length of the contractile element
v_ce	Normalized velocity of the contractile element
t_stim	Duration of stimulation of muscle

The output of getEratec_bhargava.m is a double which is equal to the energy rate of the time step in W/kg

Return values

Edot	The energy expenditure during the current time step

getErate_Houdijk()

function getErate_Houdijk	(	in	obj,
		in	F_ce,
		in	act,
		in	l_ce,
		in	v_ce
	)

Model function to calculate the energy rate of a single time.

Function to calculate the energy rate at a single time step using Houdijk et al.'s model. Houdijk et al., J Biomech, 2006. The paper desription is not optimal, see comments

Inputs are muscle parameters of the specific muscle that is considered. Inputs are muscle states of the specific muscle that is considered.

Parameters

obj	Model object
F_ce	Force in the contractile element
act	Activation level of the muscle (between 0 and 1)
l_ce	Normalized length of the contractile element
v_ce	Normalized velocity of the contractile element

The output of getErate_Houdijk.m is a double which is equal to the energy rate of the time step in W/kg

Return values

Edot	The energy expenditure during the current time step
w	Muscle work during the current time step

getErate_Lichtwark()

function getErate_Lichtwark	(	in	obj,
		in	F_ce,
		in	act,
		in	l_ce,
		in	v_ce,
		in	t_stim
	)

Model function to calculate the energy rate of a single time step using a continuous version of Lichtwark & Wilson's model.

Function to calculate the energy rate at a single time step using Lichtwark & Wilson's model, described in the supplement of Lichtwark & Wilson, J Biomech, 2007. The exception in gamma (line 68), which is according to Lichtwark & Wilson, J Exp Biol, 2005, because results were better in the 2019 comparison paper

Inputs are muscle parameters of the specific muscle that is considered.

Parameters

obj	Model object
F_ce	Force in the contractile element
act	Activation level of the muscle (between 0 and 1)
l_ce	Normalized length of the contractile element
v_ce	Normalized velocity of the contractile element
t_stim	Duration of stimulation of muscle

The output of getErate_Lichtwark.m is a double which is equal to the energy rate of the time step in W/kg

Return values

Edot	The energy expenditure during the current time step

getErate_margaria()

function getErate_margaria	(	in	obj,
		in	F_ce,
		in	v_ce
	)

Model function to calculate the energy rate of a single time step using Margaria's model.

Function to calculate the energy rate at a single time step using Margaria's model: 25 % efficient during shortening, 120% during lengthening. Margaria, Int Z Angew Physiol Einschl Arbeitsphysiol, 1968

Inputs are muscle parameters of the specific muscle that is considered.

Parameters

obj	Model object
F_ce	Force in the contractile element
v_ce	Normalized velocity of the contractile element

The output of getErate_margaria.m is a double which is equal to the energy rate of the time step in W/kg

Return values

Edot	is the energy expenditure during the current time step

getErate_Minetti()

function getErate_Minetti	(	in	obj,
		in	act,
		in	v_ce
	)

Model function to calculate the energy rate of a single time.

Function to calculate the energy rate at a single time step using Minetti's model. Based on: Minetti & Alexander, J Theor Biol, 1997. Uses muscle-level work instead of torque-level

Inputs are muscle parameters of the specific muscle that is considered.

Parameters

obj	Model object
act	activation level of the muscle (between 0 and 1)
v_ce	current velocity of the contractile element

The output of getErate_Minetti is a double which is equal to the energy rate

Return values

Edot	is the energy expenditure during the current time step

getErate_uchida()

function getErate_uchida	(	in	obj,
		in	F_ce,
		in	stim,
		in	act,
		in	l_ce,
		in	v_ce
	)

Model function to calculate the energy rate of a single time.

Function to calculate the energy rate at a single time step using Uchida's model: Uchida et al., PLOS ONE, 2016

Inputs are muscle states of the specific muscle that is considered

Parameters

obj	Model class object
F_ce	Double vector: Muscle force of CE returned by obj.getMuscleCEforces(x) (Model.nMus x 1)
stim	Double vector: Stimulation of muscles = neural excitation u (Model.nMus x 1)
act	Double vector: Activation of muscles a (Model.nMus x 1)
l_ce	Double vector: Length of contractile element of muscles s (Model.nMus x 1)
v_ce	Double vector: Velocity of contractile element of muscles (Model.nMus x 1)

The output of getErate_uchida.m is a double which is equal to the energy rate of the time step in W/kg

Return values

Edot	Double vector: Energy expenditure during one time step (energy rate) in W (Model.nMus x 1)
w_ce	Double vector: Mechanical work rate of contractile element in W/kg (normalized to muscle mass) (Model.nMus x 1)
h_sl	Double vector: Heat rate due to shortening and lengthening of muscles in W/kg (normalized to muscle mass) (Model.nMus x 1)
h_am	Double vector: Heat rate from the activation of muscles and its maintenance in W/kg (normalized to muscle mass) (Model.nMus x 1)

getErate_Umberger()

function getErate_Umberger	(	in	obj,
		in	F_ce,
		in	stim,
		in	act,
		in	l_ce,
		in	v_ce
	)

Model function to calculate the energy rate of a single time step with Umberger et al.

's model. Ross Miller's code was also used as a reference.

Function to calculate the energy rate at a single time step using Umberger's model. It uses the 2010 version (no negative work): Umberger, J R Soc Interface, 2010 2003 (original) Version: Umberger et al., "A model of human muscle energy expenditure," Computer methods in biomechanics and biomedical engineering, vol. 6, no. 2, pp. 99–111, 2003.

Inputs are muscle states of the specific muscle that is considered

Parameters

obj	Gait2dc class object
F_ce	Double vector: Muscle force of CE returned by Model.getMuscleCEforces(x) (Model.nMus x 1)
stim	Double vector: Stimulation of muscles = neural excitation u (Model.nMus x 1)
act	Double vector: Activation of muscles a (Model.nMus x 1)
l_ce	Double vector: Length of contractile element of muscles s (Model.nMus x 1)
v_ce	Double vector: Velocity of contractile element of muscles (Model.nMus x 1)

The output of getErate_Umberger.m is a double which is equal to the energy rate of the time step in W/kg

Return values

Edot	Double vector: Energy expenditure during one time step (energy rate) in W (Model.nMus x 1)
w_ce	Double vector: Mechanical work rate of contractile element in W/kg (normalized to muscle mass) (Model.nMus x 1)
h_sl	Double vector: Heat rate due to shortening and lengthening of muscles in W/kg (normalized to muscle mass) (Model.nMus x 1)
h_am	Double vector: Heat rate from the activation of muscles and its maintenance in W/kg (normalized to muscle mass) (Model.nMus x 1)

getEratec_bhargava()

function getEratec_bhargava	(	in	obj,
		in	F_ce,
		in	stim,
		in	act,
		in	l_ce,
		in	v_ce,
		in	dFdx,
		in	dFdxdot,
		in	epsilon
	)

Model function to calculate the energy rate of a single time step using a continuous version of Bhargava et al.

's model

Function to calculate the energy rate at a single time step using a continuous version of Bhargava et al.'s model. Line 60, phi, was chosen based on graphs of phi as a function of t_stim, since t_stim cannot be differentiated. Model paper: bhargava et al., J Biomech, 2004

Inputs are muscle states of the specific muscle that is considered.

Parameters

obj	Model object
F_ce	Force in the contractile element
stim	Stimulation of the muscle (between 0 and 1)
act	Activation level of the muscle (between 0 and 1)
l_ce	Normalized length of the contractile element
v_ce	Normalized velocity of the contractile element
dFdx	Derivative of CE forces with respect to the state
dFdxdot	Derivative of CE forces with respect to the state derivative
epsilon	Measure of the nonlinearity of the continuous functions

The output of getEratec_bhargava.m is a double which is equal to the energy rate of the time step in W/kg

Return values

Edot	The energy expenditure during the current time step
dEdot	The gradient of Edot with respect to all states and inputs

getEratec_Houdijk()

function getEratec_Houdijk	(	in	obj,
		in	F_ce,
		in	act,
		in	l_ce,
		in	v_ce,
		in	dFdx,
		in	dFdxdot,
		in	epsilon
	)

Model function to calculate the energy rate of a single time step using a continuous version of Houdijk et al.

's model

Function to calculate the energy rate at a single time step using a continuous version of Houdijk et al.'s model. Houdijk et al., J Biomech, 2006.

Inputs are muscle parameters of the specific muscle that is considered. Inputs are muscle states of the specific muscle that is considered.

Parameters

obj	Model object
F_ce	Force in the contractile element
act	Activation level of the muscle (between 0 and 1)
l_ce	Normalized length of the contractile element
v_ce	Normalized velocity of the contractile element
dFdx	Derivative of CE forces with respect to the state
dFdxdot	Derivative of CE forces with respect to the state derivative
epsilon	Measure of the nonlinearity of the continuous functions

The output of getEratec_Houdijk.m is a double which is equal to the energy rate of the time step in W/kg

Return values

Edot	The energy expenditure during the current time step
dEdot	The gradient of Edot with respect to all states and inputs%

getEratec_Lichtwark()

function getEratec_Lichtwark	(	in	obj,
		in	F_ce,
		in	act,
		in	l_ce,
		in	v_ce,
		in	dFdx,
		in	dFdxdot,
		in	epsilon
	)

Model function to calculate the energy rate of a single time step using a continuous version of Lichtwark & Wilson's model.

Function to calculate the energy rate at a single time step using a continuous version of Lichtwark & Wilson's model, described in the supplement of Lichtwark & Wilson, J Biomech, 2007.

Inputs are muscle parameters of the specific muscle that is considered.

Parameters

obj	Model object
F_ce	Force in the contractile element
act	Activation level of the muscle (between 0 and 1)
l_ce	Normalized length of the contractile element
v_ce	Normalized velocity of the contractile element
dFdx	Derivative of CE forces with respect to the state
dFdxdot	Derivative of CE forces with respect to the state derivative
epsilon	Measure of the nonlinearity of the continuous functions

The output of getEratec_Lichtwark.m is a double which is equal to the energy rate of the time step in W/kg

Return values

Edot	The energy expenditure during the current time step
dEdot	The gradien

getEratec_margaria()

function getEratec_margaria	(	in	obj,
		in	F_ce,
		in	v_ce,
		in	dFdx,
		in	dFdxdot,
		in	epsilon
	)

Model function to calculate the energy rate of a single time step using a continuous version of Margaria's model.

Function to calculate the energy rate at a single time step using a continuous version of Margaria's model: 25 % efficient during shortening, 120% during lengthening. Margaria, Int Z Angew Physiol Einschl Arbeitsphysiol, 1968

Inputs are muscle parameters of the specific muscle that is considered.

Parameters

obj	Model object
F_ce	Force in the contractile element
v_ce	Normalized velocity of the contractile element
dFdx	Derivative of CE forces with respect to the state
dFdxdot	Derivative of CE forces with respect to the state derivative
epsilon	Measure of the nonlinearity of the continuous functions

The output of getEratec_margaria.m is a double which is equal to the energy rate of the time step in W/kg

Return values

Edot	is the energy expenditure during the current time step
dEdot	is the gradient of Edot with respect to all states and inputs

getEratec_Minetti()

function getEratec_Minetti	(	in	obj,
		in	act,
		in	v_ce
	)

Model function to calculate the energy rate of a single time step using Minetti's model.

No discsontinuities here, so it is the same as the original model.

Function to calculate the energy rate at a single time step using Minetti's model. Based on: Minetti & Alexander, J Theor Biol, 1997. Uses muscle-level work instead of torque-level

Inputs are muscle parameters of the specific muscle that is considered.

Parameters

obj	Model object
act	activation level of the muscle (between 0 and 1)
v_ce	current velocity of the contractile element

The output of getEratec_Minetti.m is a double which is equal to the energy rate of the time step in W/kg

Return values

Edot	is the energy expenditure during the current time step
dEdot	is the gradient of Edot with respect to all states and inputs

getEratec_umberger()

function getEratec_umberger	(	in	obj,
		in	F_ce,
		in	stim,
		in	act,
		in	l_ce,
		in	v_ce,
		in	dFdx,
		in	dFdxdot,
		in	epsilon
	)

Model function to calculate the energy rate of a single time step with the continuous version of Umberger et al.

's model

Function to calculate the energy rate at a single time step using a continuous version of Umberger's model. This one is published in Koelewijn, Dorscky et al., Comp Meth Biomed Biomech Eng, 2016, and uses the 2010 version (no negative work): Umberger, J R Soc Interface, 2010

Inputs are muscle states of the specific muscle that is considered.

Parameters

obj	Model object
F_ce	Force in the contractile element
stim	Stimulation of the muscle (between 0 and 1)
act	Activation level of the muscle (between 0 and 1)
l_ce	Normalized length of the contractile element
v_ce	Normalized velocity of the contractile element
dFdx	Derivative of CE forces with respect to the state
dFdxdot	Derivative of CE forces with respect to the state derivative
epsilon	Measure of the nonlinearity of the continuous functions

The output of getEratec_umberger.m is a double which is equal to the energy rate of the time step in W/kg

Return values

Edot	The energy expenditure during the current time step
dEdot	The gradient of Edot with respect to all states and inputs

getGRF()

virtual getGRF ( in  obj, in  x  )

virtual

Abstract function returning the ground reaction forces for the system in state x.

Reimplemented in Gait2d_osim, Gait2dc, and Gait3d.

getJointmoments()

virtual getJointmoments ( in  obj, in  x, in  u  )

virtual

Abstract function returns joint moments, for the system in state x.

Reimplemented in Gait2d_osim, Gait2dc, and Gait3d.

getMetabolicRate_pernode()

function getMetabolicRate_pernode	(	in	obj,
		in	x,
		in	xdot,
		in	u,
		in	t_stim,
		in	name,
		in	getCont,
		in	epsilon,
		in	exponent
	)

Model function to calculate metabolic cost of a movement.

Function to calculate the metabolic cost of a movement. Seven different models are currently implemented

Parameters

obj	Model object
x	Double vector: States of the current node
xdot	Double vector: Derivatives of states
u	Double vector: Controls of the current node
t_stim	Double vector: how long each muscle was already stimulated
name	(optional) String: name of the model that is being used. Options are umberger, lichtwark, bhargava, margaria, minetti, houdijk, and uchida
getCont	(optional) Boolean: If true, get the continuous version which is needed if we use the output for simulation. (default: 0)
epsilon	(optional) double parameter: Measure of nonlinearity of model, which is only used in the continuous model version. Default 0.
exponent	(optional) integer: if metabolic cost is the objective, this number allows to minimize the square, cube, or nth-power of metabolic cost. Default is 1

Return values

Edot	Double vector: Energy expenditure during one time step (energy rate) in W (Model.nMus x 1)
dEdotdx	Double vector: Derivative of Edot w.r.t to x (Model.nStates x 1)
dEdotdu	Double vector: Derivative of Edot w.r.t to u (Model.nControls x 1)
dEdotdT	Double: Derivative of Edot w.r.t to T

getMuscleCEforces()

virtual getMuscleCEforces ( in  obj, in  x, in  xdot  )

virtual

Abstract function returning muscle forces of CE for the system in state x.

Reimplemented in Gait2d_osim, Gait2dc, and Gait3d.

getMuscleCEpower()

virtual getMuscleCEpower ( in  obj, in  x, in  xdot  )

virtual

Abstract function returns power generated by muscle contractile elements, for the system in state x.

Reimplemented in Gait2d_osim, Gait2dc, and Gait3d.

getMuscleforces()

virtual getMuscleforces ( in  obj, in  x  )

virtual

Abstract function returning muscle forces for the system in state x.

Reimplemented in Gait2d_osim, Gait2dc, and Gait3d.

initMex()

virtual initMex ( in  obj )

protectedvirtual

Abstract function to initialize model mex file.

Reimplemented in Gait2d_osim, Gait2dc, and Gait3d.

initModel()

virtual initModel ( in  obj, in  vargin  )

protectedvirtual

Abstract function to initialize with default parameters.

Reimplemented in Gait2dc.

setbodymass()

function setbodymass	(	in	obj,
		in	bodymass
	)

Function to set body mass, does not influence the.

Parameters

obj	Model class object
segmentTable	Double: bodymass

setMuscles()

function setMuscles	(	in	obj,
		in	muscles
	)

Function to set the muscles table.

Parameters

obj	Model class object
segmentTable	Table: muscles

setSegmentMass()

function setSegmentMass	(	in	obj,
		in	segmentName,
		in	segmentMass
	)

Function to set segment mass.

Parameters

obj	Model class object
segmentName	String: Name of the segment
segmentMass	Double: Mass of the segment in kg

setSegments()

function setSegments	(	in	obj,
		in	segmentTable
	)

Function to set segment Table.

Parameters

obj	Model class object
segmentTable	Table: segmentTable

showStick()

virtual showStick ( in  obj, in  x  )

virtual

Abstract function to show model as stick figure.

simuAccGyro()

virtual simuAccGyro ( in  obj, in  data, in  q, in  qd, in  qdd  )

virtual

Abstract function to simulate acceleration and gyroscope signals.

update_constraints()

virtual update_constraints ( in  obj )

protectedvirtual

Abstract function defining the table Model.constraints.

Reimplemented in Gait2d_osim, Gait2dc, and Gait3d.

update_controls()

virtual update_controls ( in  obj )

protectedvirtual

Abstract function defining the table Model.controls.

Reimplemented in Gait2d_osim, Gait2dc, and Gait3d.

update_idxControls()

function update_idxControls ( in  obj )

protected

Function defining Model.hidxControls.

Parameters

obj	Model class object

update_idxForward()

function update_idxForward ( in  obj )

protected

Function defining Model.idxForward.

Provides the indices of state variables that have forward translation. States have to be updated before!

Parameters

obj	Model class object

update_idxForwardAll()

function update_idxForwardAll ( in  obj )

protected

Function defining Model.idxForwardAll.

Provides the indices of state variables that have forward translation, speed, position of contact points and force at contact points. States and idxForward have to be updated before!

Parameters

obj	Model class object

update_idxSideward()

function update_idxSideward ( in  obj )

protected

Function defining Model.idxSideward.

Provides the indices of state variables that have sideward translation. States have to be updated before!

Parameters

obj	Model class object

update_idxSidewardAll()

function update_idxSidewardAll ( in  obj )

protected

Function defining Model.idxSidewardAll.

Provides the indices of state variables that have sideward translation, speed, position of contact points and force at contact points. States and idxSideward have to be updated before!

Parameters

obj	Model class object

update_idxStates()

function update_idxStates ( in  obj )

protected

Function defining Model.hidxStates.

Parameters

obj	Model class object

update_idxSymmetry()

virtual update_idxSymmetry ( in  obj )

protectedvirtual

Abstract function defining Model.idxSymmetry.

Reimplemented in Gait2d_osim, Gait2dc, and Gait3d.

update_idxTorqueDof()

function update_idxTorqueDof ( in  obj )

protected

Function defining Model.idxTorqueDof.

Searches for indices of dof which have torque actuators in Model.torques.

Parameters

obj	Model class object

update_idxUpward()

function update_idxUpward ( in  obj )

protected

Function defining Model.idxUpward.

Provides the indices of state variables that have upward translation. States have to be updated before!

Parameters

obj	Model class object

update_mexParameter()

virtual update_mexParameter ( in  obj, in  src, in  evnt  )

protectedvirtual

Abstract function performed to update the parameter of the mex and the tables.

Reimplemented in Gait2d_osim, Gait2dc, and Gait3d.

update_states()

virtual update_states ( in  obj )

protectedvirtual

Abstract function defining the table Model.states.

Reimplemented in Gait2d_osim, Gait2dc, and Gait3d.

Member Data Documentation

constraints

Property constraints

protected

Table: Information on constraints implemented in the mex and here.

controls

Property controls

protected

Table: Information on controls of the model.

CPs

Property CPs

Table: Contact points.

dofs

Property dofs

Table: Degrees of freedom (Range of Dofs should not be changed here.

Set the bounds of the Problem instead.)

drag_coefficient

Property drag_coefficient

Double: Air drag coefficient in N/(m/s)^2 (default: 0.2128)

gravity

Property gravity

Double array: Gravity vector in m/(s^2)

GRFNAMES

Constant Property GRFNAMES = {'rightFx', 'rightFy', 'rightFz', 'rightMx', 'rightMy', 'rightMz', 'leftFx', 'leftFy', 'leftFz', 'leftMx', 'leftMy', 'leftMz' }

Cell array with string: Gives the names for the GRF vector returned by getGRF()

idxForward

Property idxForward

protected

Double array: Indices for forward translation.

idxForwardAll

Property idxForwardAll

protected

Double array: Indices for forward translation, speed, position of contact points and force at contact points.

idxSideward

Property idxSideward

protected

Double array: Indices for sideward translation.

idxSidewardAll

Property idxSidewardAll

protected

Double array: Indices for sideward translation, speed, position of contact points and force at contact points.

idxSymmetry

Property idxSymmetry

protected

Struct: Double arrays with indices for symmetry to map right to left.

idxTorqueDof

Property idxTorqueDof

protected

Double array: Indices of dofs of torque actuators.

idxUpward

Property idxUpward

protected

Double array: Indices for upward translation.

init

Property init

protected

Double: Showing if the mex model is initialized.

joints

Property joints

Table: Joints.

mExtraScaleFactor

Property mExtraScaleFactor

Double: Scale factor for extra torques in Nm (default: 100 since we used this in previous simulations.

However, it's probably overwritten in the construction (see Gait3d.m)!)

muscles

Property muscles

Table: Muscles.

nConstraints

Property nConstraints

protected

Double: Number of constraints (height of Model.constraints)

nControls

Property nControls

protected

Double: Number of controls (height of Model.controls)

nCPs

Property nCPs

protected

Double: Number of contact points (height of Model.CPs)

nDofs

Property nDofs

protected

Double: Number of degree of freedoms (height of Model.dofs)

nJoints

Property nJoints

protected

Double: Number of joints (height of Model.joints)

nMus

Property nMus

protected

Double: Number of muscles (height of Model.muscles)

nSegments

Property nSegments

protected

Double: Number of segments (height of Model.segments)

nStates

Property nStates

protected

Double: Number of states (height of Model.states)

nTor

Property nTor

protected

Double: Number of torque actuators (height of Model.torques)

segments

Property segments

protected

Table: Segments (Segment properties should not be changed)

states

Property states

protected

Table: Information on states of the model.

torques

Property torques

Table: Torque actuators.

wind_speed

Property wind_speed

Double: Wind speed in direction of +X in m/s (default: 0)

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

• BioMAC-Sim-Toolbox/src/model/@Model/Model.m