664 lines
26 KiB
C++
664 lines
26 KiB
C++
#ifndef TORQUEMUSCLEFUNCTIONFACTORY_H_
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#define TORQUEMUSCLEFUNCTIONFACTORY_H_
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/*-------------------------------------------------------------------------
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OpenSim: SmoothSegmentedFunctionFactory.cpp
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--------------------------------------------------------------------------
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The OpenSim API is a toolkit for musculoskeletal modeling and simulation.
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See http:%opensim.stanford.edu and the NOTICE file for more information.
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OpenSim is developed at Stanford University and supported by the US
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National Institutes of Health (U54 GM072970, R24 HD065690) and by DARPA
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through the Warrior Web program.
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Copyright (c) 2005-2012 Stanford University and the Authors
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Author(s): Matthew Millard
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Licensed under the Apache License, Version 2.0 (the 'License'); you may
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not use this file except in compliance with the License. You may obtain a
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copy of the License at http:%www.apache.org/licenses/LICENSE-2.0.
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an 'AS IS' BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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--------------------------------------------------------------------------
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Derivative work
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Date : September 2016
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Authors(s): Millard
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Updates : Made active torque-angle, passive-torque-angle, torque-velocity
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and tendon-torque-angle curves based on the equivalent line-type
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curves in OpenSim.
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*/
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#include "../geometry/SmoothSegmentedFunction.h"
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#include "../geometry/SegmentedQuinticBezierToolkit.h"
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#include <cstdio>
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#include <iostream>
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#include <fstream>
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#include <cmath>
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namespace RigidBodyDynamics {
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namespace Addons {
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namespace Muscle{
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class TorqueMuscleFunctionFactory
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{
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public:
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/**
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This is a function that will produce a C2 (continuous to the second
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derivative) active torque angle curve. This Bezier curve has been
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fitted to match the active-torque-angle curve described in
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Anderson, Dennis E., Michael L. Madigan, and Maury A. Nussbaum.
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"Maximum voluntary joint torque as a function of joint angle and
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angular velocity: model development and application to the lower
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limb." Journal of biomechanics 40, no. 14 (2007): 3105-3113.
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but note that its range is normalized to [0,1].
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@param c2 (radians)
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The active-torque-angle width parameter. The parameter c2
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is defined by Anderson et al. as
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c2 = pi/(theta_max - theta_min).
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@param c3 : (radians)
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Then angle which has the largest active-torque.
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@param curveName The name of the joint torque this curve applies to. This
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curve name should have the name of the joint and the
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direction (e.g. hipExtensionTorqueMuscle) so that if
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this curve ever causes an exception, a user friendly
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error message can be displayed to the end user to help
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them debug their model.
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@param smoothSegmentedFunctionToUpdate
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A SmoothSegmentedFunction object that will be erased and filled with
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the coefficients that are defined by this curve.
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*/
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static void createAnderson2007ActiveTorqueAngleCurve(
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double c2,
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double c3,
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const std::string& curveName,
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RigidBodyDynamics::Addons::Geometry::SmoothSegmentedFunction&
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smoothSegmentedFunctionToUpdate);
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/**
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This is a function that will produce a C2 (continuous to the second
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derivative) active torque (angular) velocity curve. This Bezier curve
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has been fitted to match the active-torque-angle curve described in
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Anderson, Dennis E., Michael L. Madigan, and Maury A. Nussbaum.
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"Maximum voluntary joint torque as a function of joint angle and
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angular velocity: model development and application to the lower
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limb." Journal of biomechanics 40, no. 14 (2007): 3105-3113.
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While the concentric side of the Bezier curve and the original
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formulation match, the eccentric side does not: the equations
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Anderson et al. chose decrease down to 0 rapidly. Since Anderson
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et al. did not collect data at the higher eccentric velocities the
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oddities in their chosen curves are likely due to the parameterization
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they chose. The eccentric side of the Bezier curve will be fitted
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so that, if possible, it passes close to the value of the original
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curves for theta = -60 deg/s within the limits imposed by
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minEccentricMultiplier and maxEccentricMultiplier.
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@param c4 (rads/s)
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Angular velocity when the torque is 75% of the maximum
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isometric torque.
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@param c5 (rads/s)
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Angular velocity when the torque is 50% of the maximum
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isometric torque.
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@param c6
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Multiplier that Anderson et al. uses to describe the
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change in slope of the curve as the contraction velocity
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changes sign from + to -.
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@param minEccentricMultiplier
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The minimum value of the torque-(angular)-velocity curve
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tends to at large eccentric contraction velocities. Note
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minEccentricMultiplier > 1.0
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@param maxEccentricMultiplier
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The value of the torque-(angular)-velocity curve tends
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to at large eccentric contraction velocities. Note
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maxEccentricMultiplier > minEccentricMultiplier.
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@param curveName The name of the joint torque this curve applies to. This
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curve name should have the name of the joint and the
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direction (e.g. hipExtensionTorqueMuscle) so that if
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this curve ever causes an exception, a user friendly
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error message can be displayed to the end user to help
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them debug their model.
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@param smoothSegmentedFunctionToUpdate
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A SmoothSegmentedFunction object that will be erased and filled with
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the coefficients that are defined by this curve.
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*/
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static void createAnderson2007ActiveTorqueVelocityCurve(
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double c4,
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double c5,
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double c6,
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double minEccentricMultiplier,
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double maxEccentricMultiplier,
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const std::string& curveName,
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RigidBodyDynamics::Addons::Geometry::SmoothSegmentedFunction&
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smoothSegmentedFunctionToUpdate);
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/**
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This is a function that will produce a C2 (continuous to the second
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derivative) passive torque angle curve described in
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Anderson, Dennis E., Michael L. Madigan, and Maury A. Nussbaum.
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"Maximum voluntary joint torque as a function of joint angle and
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angular velocity: model development and application to the lower
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limb." Journal of biomechanics 40, no. 14 (2007): 3105-3113.
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Note the following differences between this implementation and
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the original equations presented in Anderson et al.:
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1. This function will return a curve that is fitted to the
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positive side of the curve defined by the coefficients
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b1, k1, b2, and k2. Because of the sign convention employed by
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Anderson et al. the positive side of the curve corresponds to
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the passive curve generated by the torque actuator associated
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with the rest of the coefficients.
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2. This function has been normalized so that a value of 1.0
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corresponds to one-maximum-isometric-active-contraction
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torque, or c1*subjectWeightInNewtons*subjectHeightInMeters.
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@param scale
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The scaling factor used on the c1 column in Table 3 of
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Anderson et al.:
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scale = subjectWeightInNewtons * subjectHeightInMeters
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@param c1
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The normalized c1 parameter listed in Tabel 3 of
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Anderson et al.
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@param b1
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The passive torque angle curve parameter used in
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Anderson et al.'s Eqn. 1:
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torquePassive = b1*exp(k1*theta) + b2*exp(k2*theta)
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@param k1
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The term k1 in Anderson et al.'s Eqn. 1.
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@param b2
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The term b2 in Anderson et al.'s Eqn. 1.
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@param k2
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The term k2 in Anderson et al.'s Eqn. 1.
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@param curveName The name of the joint torque this curve applies to. This
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curve name should have the name of the joint and the
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direction (e.g. hipExtensionTorqueMuscle) so that if
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this curve ever causes an exception, a user friendly
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error message can be displayed to the end user to help
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them debug their model.
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@param smoothSegmentedFunctionToUpdate
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A SmoothSegmentedFunction object that will be erased and filled with
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the coefficients that are defined by this curve.
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*/
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static void createAnderson2007PassiveTorqueAngleCurve(
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double scale,
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double c1,
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double b1,
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double k1,
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double b2,
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double k2,
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const std::string& curveName,
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RigidBodyDynamics::Addons::Geometry::SmoothSegmentedFunction&
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smoothSegmentedFunctionToUpdate);
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/**
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This function creates a normalized torque-velocity curve. The concentric
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side of the curve is fitted to Hill's hyperbola that passes through
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the value of tv-at-half-of-the-maximum-concentric-velocity (a parameter
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supplied by the user). The eccentric side of the curve rapidly, but smoothly
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approaches a terminal value of
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tv-at-the-maximum-eccentric-contraction-velocity. Outside of the normalized
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velocities of -1 to 1 the curve takes the values of 0, and
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tvAtEccentricOmegaMax respectively with a slope of 0.
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\image html fig_MuscleAddon_TorqueMuscleFunctionFactory_TorqueVelocityCurveSimple.png
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@param tvAtEccentricOmegaMax
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The value of the torque-velocity-multiplier at the maximum
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eccentric contraction velocity. This value must be
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@param tvAtHalfConcentricOmegaMax
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The value of the torque-velocity-
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@param curveName The name of the joint torque this curve applies to. This
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curve name should have the name of the joint and the
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direction (e.g. hipExtensionTorqueMuscle) so that if
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this curve ever causes an exception, a user friendly
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error message can be displayed to the end user to help
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them debug their model.
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@param smoothSegmentedFunctionToUpdate
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A SmoothSegmentedFunction object that will be erased and filled with
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the coefficients that are defined by this curve.
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<b>aborts</b>
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-tvAtEccentricOmegaMax < 1.05
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-tvAtHalfOmegaMax >= 0.45
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-tvAtHalfOmegaMax <= 0.05
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<b>References</b>
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Hill, A. V. (1938). The heat of shortening and the dynamic constants of
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muscle. Proceedings of the Royal Society of London B: Biological Sciences,
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126(843), 136-195.
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*/
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static void createTorqueVelocityCurve(
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double tvAtEccentricOmegaMax,
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double tvAtHalfConcentricOmegaMax,
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const std::string& curveName,
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RigidBodyDynamics::Addons::Geometry::SmoothSegmentedFunction&
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smoothSegmentedFunctionToUpdate );
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/**
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This function creates a normalized torque-velocity curve. The concentric
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side of the curve is fitted to Hill's hyperbola that passes through
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the value of tv-at-half-of-the-maximum-concentric-velocity (a parameter
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supplied by the user). The eccentric side of the curve rapidly, but smoothly
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approaches a terminal value of
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tv-at-the-maximum-eccentric-contraction-velocity. Shape of the eccentric
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side of the curve can be changed using the slopeNearEccentricOmegaMax
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and curviness variables. Outside of the normalized
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velocities of -1 to 1 the curve takes the values of
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slopeAtConcentricOmegaMax and slopeAtEccentricOmegaMax respectively.
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\image html fig_MuscleAddon_TorqueMuscleFunctionFactory_TorqueVelocityCurve.png
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@param tvAtEccentricOmegaMax
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The value of the torque-velocity-multiplier at the maximum
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eccentric contraction velocity. This value must be
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@param tvAtHalfConcentricOmegaMax
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The value of the torque-velocity-
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@param slopeAtConcentricOmegaMax
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The slope of the curve at a normalized angular velocity of -1. This slope
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is used to extrapolate \f$\mathbf{t}_V\f$ for normalized angular velocities
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of less than -1.
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@param slopeNearEccentricOmegaMax
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The slope of the eccentric side of the curve as the normalized angular
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velocity approaches 1.
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@param slopeAtEccentricOmegaMax
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The slope of the curve at a normalized angular velocity of 1. This slope
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is used to extrapolate \f$\mathbf{t}_V\f$ for normalized angular velocities
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of greater than 1.
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@param eccentricCurviness
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This parameter controls the shape of the curve between the normalized
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angular velocities of 0 and 1. An eccentricCurviness of 0 will flatten
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the elbow so that the curve closely follows a line that begins at (0,1)
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and ends at (1,tvAtEccentricOmegaMax). An eccentricCurviness of 1 will
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give the curve a strong elbow so that it quickly approaches the line that
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passes through the point (1,tvAtEccentricOmegaMax) and has a slope of
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slopeNearEccentricOmegaMax.
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@param curveName The name of the joint torque this curve applies to. This
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curve name should have the name of the joint and the
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direction (e.g. hipExtensionTorqueMuscle) so that if
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this curve ever causes an exception, a user friendly
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error message can be displayed to the end user to help
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them debug their model.
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@param smoothSegmentedFunctionToUpdate
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A SmoothSegmentedFunction object that will be erased and filled with
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the coefficients that are defined by this curve.
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<b>aborts</b>
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-tvAtEccentricOmegaMax < 1.05
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-tvAtHalfOmegaMax > 0.45 or tvAtHalfOmegaMax < 0.05
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-slopeAtConcentricOmegaMax < 0
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-slopeNearEccentricOmegaMax < 0
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-slopeAtEccentricOmegaMax < 0
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-eccentricCurviness < 0 or eccentricCurviness > 1
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<b>References</b>
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Hill, A. V. (1938). The heat of shortening and the dynamic constants of
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muscle. Proceedings of the Royal Society of London B: Biological Sciences,
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126(843), 136-195.
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*/
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static void createTorqueVelocityCurve(
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double tvAtEccentricOmegaMax,
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double tvAtHalfConcentricOmegaMax,
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double slopeAtConcentricOmegaMax,
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double slopeNearEccentricOmegaMax,
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double slopeAtEccentricOmegaMax,
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double eccentricCurviness,
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const std::string& curveName,
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RigidBodyDynamics::Addons::Geometry::SmoothSegmentedFunction&
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smoothSegmentedFunctionToUpdate );
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/**
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This function creates a Bezier spline that closely follows the
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exponential curves that are typically used to model the passive-torque-angle
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characteristic of muscles. This curve has a value and a slope of zero
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for angles that are less than abs(angleAtZeroTorque). For angles that
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have an absolute magnitude larger than abs(angleAtOneNormTorque) the curve
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is simply linearly extrapolated.
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Note that curves can be represented that increase left-to-right, or
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decrease left-to-right by setting the variables angleAtOneNormTorque and
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angleAtZeroTorque correctly. For example using (0,1) for
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angleAtOneNormTorque and angleAtZeroTorque produces a curve that increases
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left-to-right while using (-1,0) produces a curve that decreases left to
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right.
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\image html fig_MuscleAddon_TorqueMuscleFunctionFactory_PassiveTorqueAngleCurveSimple.png
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@param angleAtZeroTorque is the angle at which the curve transitions from
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a flat line and begins curving upwards. (radians)
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@param angleAtOneNormTorque is the angle at which this curve achieves a
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value of 1.0. (radians)
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@param curveName The name of the joint torque this curve applies to. This
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curve name should have the name of the joint and the
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direction (e.g. hipExtensionTorqueMuscle) so that if
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this curve ever causes an exception, a user friendly
|
|
error message can be displayed to the end user to help
|
|
them debug their model.
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@param smoothSegmentedFunctionToUpdate
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A SmoothSegmentedFunction object that will be erased and filled with
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the coefficients that are defined by this curve.
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<b>aborts</b>
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- abs(angleAtOneNormTorque-angleAtZeroTorque) < sqrt(eps)
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*/
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static void createPassiveTorqueAngleCurve(
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double angleAtZeroTorque,
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double angleAtOneNormTorque,
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const std::string& curveName,
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RigidBodyDynamics::Addons::Geometry::SmoothSegmentedFunction&
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smoothSegmentedFunctionToUpdate );
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/**
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This function creates a Bezier spline that closely follows the
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exponential curves that are typically used to model the passive-torque-angle
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characteristic of muscles. This curve has a value and a slope of zero
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for angles that are less than abs(angleAtZeroTorque). For angles that
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have an absolute magnitude larger than abs(angleAtOneNormTorque) the curve
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is simply linearly extrapolated.
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Note that curves can be represented that increase left-to-right, or
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decrease left-to-right by setting the variables angleAtOneNormTorque and
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angleAtZeroTorque correctly. For example using (0,1) for
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angleAtOneNormTorque and angleAtZeroTorque produces a curve that increases
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left-to-right while using (-1,0) produces a curve that decreases left to
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right.
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\image html fig_MuscleAddon_TorqueMuscleFunctionFactory_PassiveTorqueAngleCurve.png
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@param angleAtZeroTorque is the angle at which the curve transitions from
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a flat line and begins curving upwards. (radians)
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@param angleAtOneNormTorque is the angle at which this curve achieves a
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value of 1.0. (radians)
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@param stiffnessAtLowTorque
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The normalized stiffness (or slope) of the curve achieves as it begins
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to increase. This is usually chosen to be a small, but non-zero fraction
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of stiffnessAtOneNormTorque
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(stiffnessAtLowTorque = 0.025 stiffnessAtOneNormTorque is typical).
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The sign of stiffnessAtLowTorque must be positive if
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angleAtOneNormTorque > angleAtZeroPassiveTorque. The sign
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of stiffnessAtLowTorque must be negative if
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angleAtOneNormTorque < angleAtZeroPassiveTorque.
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(Norm.Torque/radians)
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@param stiffnessAtOneNormTorque
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The normalized stiffness (or slope) of the fiber curve
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when the fiber is stretched by
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angleAtOneNormTorque - angleAtZeroPassiveTorque. The sign
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of stiffnessAtOneNormTorque must agree with stiffnessAtLowTorque.
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(Norm.Torque/radians)
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@param curviness
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The dimensionless 'curviness' parameter that
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can vary between 0 (a line) to 1 (a smooth, but
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sharply bent elbow). A value of 0.5 is typical as it produces a
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graceful curve.
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@param curveName The name of the joint torque this curve applies to. This
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curve name should have the name of the joint and the
|
|
direction (e.g. hipExtensionTorqueMuscle) so that if
|
|
this curve ever causes an exception, a user friendly
|
|
error message can be displayed to the end user to help
|
|
them debug their model.
|
|
|
|
@param smoothSegmentedFunctionToUpdate
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|
A SmoothSegmentedFunction object that will be erased and filled with
|
|
the coefficients that are defined by this curve.
|
|
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<b>aborts</b>
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- abs(angleAtOneNormTorque-angleAtZeroTorque) < sqrt(eps)
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- sign(stiffnessAtLowTorque) != sign(angleAtOneNormTorque-angleAtLowTorque)
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- sign(stiffnessAtOneNormTorque) != sign(stiffnessAtLowTorque)
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- abs(stiffnessAtLowTorque) > 0.9/abs(angleAtOneNormTorque-angleAtZeroTorque)
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- abs(stiffnessAtOneTorque) <= 1.1/abs(angleAtOneNormTorque-angleAtZeroTorque)
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- curviness < 0 or curviness > 1
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*/
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static void createPassiveTorqueAngleCurve(
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double angleAtZeroTorque,
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double angleAtOneNormTorque,
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double stiffnessAtLowTorque,
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double stiffnessAtOneNormTorque,
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double curviness,
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const std::string& curveName,
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RigidBodyDynamics::Addons::Geometry::SmoothSegmentedFunction&
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smoothSegmentedFunctionToUpdate );
|
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|
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|
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/**
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|
This function produces a Bezier curve fitted to a Gaussian function. As the
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tails of the Gaussian curve become small this curve is simply extrapolated
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|
as a line with a y-value of zero and a slope of zero.
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\image html fig_MuscleAddon_TorqueMuscleFunctionFactory_GaussianActiveTorqueAngleCurveSimple.png
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|
|
@param angleAtOneNormTorque The angle at which the Gaussian curve develops
|
|
a value of 1.
|
|
|
|
@param angularStandardDeviation The angular deviation from
|
|
the mean at which the Gaussian curve reaches a value of \f$e^{-1/2}\f$.
|
|
|
|
@param curveName The name of the joint torque this curve applies to. This
|
|
curve name should have the name of the joint and the
|
|
direction (e.g. hipExtensionTorqueMuscle) so that if
|
|
this curve ever causes an exception, a user friendly
|
|
error message can be displayed to the end user to help
|
|
them debug their model.
|
|
|
|
@param smoothSegmentedFunctionToUpdate
|
|
A SmoothSegmentedFunction object that will be erased and filled with
|
|
the coefficients that are defined by this curve.
|
|
|
|
<b>aborts</b>
|
|
- angularWidthOfOneStandardDeviation < sqrt(eps)
|
|
*/
|
|
static void createGaussianShapedActiveTorqueAngleCurve(
|
|
double angleAtOneNormTorque,
|
|
double angularStandardDeviation,
|
|
const std::string& curveName,
|
|
RigidBodyDynamics::Addons::Geometry::SmoothSegmentedFunction&
|
|
smoothSegmentedFunctionToUpdate
|
|
);
|
|
|
|
|
|
/**
|
|
This function produces a C2 continuous Bezier curve fitted to a Gaussian
|
|
function. As the tails of the Gaussian curve become less than
|
|
minValueAtShoulders, the curve is linearly extrapolated at a sloe of
|
|
minSlopeOfShoulders.
|
|
|
|
\image html fig_MuscleAddon_TorqueMuscleFunctionFactory_GaussianActiveTorqueAngleCurve.png
|
|
|
|
@param angleAtOneNormTorque The angle at which the Gaussian curve develops
|
|
a value of 1.
|
|
|
|
@param angularStandardDeviation The angular deviation from
|
|
the mean at which the Gaussian curve reaches a value of \f$e^{-1/2}\f$.
|
|
|
|
@param minSlopeAtShoulders The y-value at which the Bezier curve transitions
|
|
from having a shape like a Gaussian curve to being linearly extrapolated.
|
|
|
|
@param minValueAtShoulders The slope of the linear extrapolation of the
|
|
Bezier curve for y-values that are less than minSlopeAtShoulders. The
|
|
sign of minValueAtShoulders is automatically set so that it matches the
|
|
curve near it (see the figure).
|
|
|
|
@param curviness
|
|
The dimensionless 'curviness' parameter that
|
|
can vary between 0 (a line) to 1 (a smooth, but
|
|
sharply bent elbow). A value of 0.5 is typical as it produces a
|
|
graceful curve.
|
|
|
|
@param curveName The name of the joint torque this curve applies to. This
|
|
curve name should have the name of the joint and the
|
|
direction (e.g. hipExtensionTorqueMuscle) so that if
|
|
this curve ever causes an exception, a user friendly
|
|
error message can be displayed to the end user to help
|
|
them debug their model.
|
|
|
|
@param smoothSegmentedFunctionToUpdate
|
|
A SmoothSegmentedFunction object that will be erased and filled with
|
|
the coefficients that are defined by this curve.
|
|
|
|
<b>aborts</b>
|
|
- angularWidthOfOneStandardDeviation < sqrt(eps)
|
|
- minSlopeAtShoulders < 0
|
|
- minValueAtShoulders < 0
|
|
- curviness > 1 or curviness < 0
|
|
|
|
*/
|
|
static void createGaussianShapedActiveTorqueAngleCurve(
|
|
double angleAtOneNormTorque,
|
|
double angularStandardDeviation,
|
|
double minSlopeAtShoulders,
|
|
double minValueAtShoulders,
|
|
double curviness,
|
|
const std::string& curveName,
|
|
RigidBodyDynamics::Addons::Geometry::SmoothSegmentedFunction&
|
|
smoothSegmentedFunctionToUpdate
|
|
);
|
|
|
|
|
|
/**
|
|
This function produces a normalized tendon-torque-angle curve with a
|
|
toe region that is in the range of \f$\mathbf{t}_V\f$ [0,1./3,] after which
|
|
the curve is linearly extrapolated.
|
|
|
|
\image html fig_MuscleAddon_TorqueMuscleFunctionFactory_TendonTorqueAngleCurveSimple.png
|
|
|
|
@param angularStretchAtOneNormTorque The amount of angular stretch of the
|
|
joint as the tendon goes from developing zero torque at its slack length
|
|
to developing one maximum isometric torque. (radians)
|
|
|
|
@param curveName The name of the joint torque this curve applies to. This
|
|
curve name should have the name of the joint and the
|
|
direction (e.g. hipExtensionTorqueMuscle) so that if
|
|
this curve ever causes an exception, a user friendly
|
|
error message can be displayed to the end user to help
|
|
them debug their model.
|
|
|
|
@param smoothSegmentedFunctionToUpdate
|
|
A SmoothSegmentedFunction object that will be erased and filled with
|
|
the coefficients that are defined by this curve.
|
|
|
|
<b>aborts</b>
|
|
- angularWidthOfOneStandardDeviation < sqrt(eps)
|
|
|
|
*/
|
|
static void createTendonTorqueAngleCurve(
|
|
double angularStretchAtOneNormTorque,
|
|
const std::string& curveName,
|
|
RigidBodyDynamics::Addons::Geometry::SmoothSegmentedFunction&
|
|
smoothSegmentedFunctionToUpdate
|
|
);
|
|
|
|
/**
|
|
This function produces a normalized tendon-torque-angle curve with a
|
|
toe region, final stiffness, and shape that can be controlled.
|
|
|
|
\image html fig_MuscleAddon_TorqueMuscleFunctionFactory_TendonTorqueAngleCurve.png
|
|
|
|
@param angularStretchAtOneNormTorque The amount of angular stretch of the
|
|
joint as the tendon goes from developing zero torque at its slack length
|
|
to developing one maximum isometric torque. (radians)
|
|
|
|
@param stiffnessAtOneNormTorque The linear stiffness value of the tendon
|
|
that is used for all y-values greater than the toe region.
|
|
(Norm. Torque/rad)
|
|
|
|
@param normTorqueAtToeEnd The normalized torque value which defines the
|
|
end of the nonlinear-stiffness region of the tendon and the beginning of
|
|
the linear stiffness region of the tendon.
|
|
|
|
@param curviness
|
|
The dimensionless 'curviness' parameter that
|
|
can vary between 0 (a line) to 1 (a smooth, but
|
|
sharply bent elbow). A value of 0.5 is typical as it produces a
|
|
graceful curve.
|
|
|
|
@param curveName The name of the joint torque this curve applies to. This
|
|
curve name should have the name of the joint and the
|
|
direction (e.g. hipExtensionTorqueMuscle) so that if
|
|
this curve ever causes an exception, a user friendly
|
|
error message can be displayed to the end user to help
|
|
them debug their model.
|
|
|
|
@param smoothSegmentedFunctionToUpdate
|
|
A SmoothSegmentedFunction object that will be erased and filled with
|
|
the coefficients that are defined by this curve.
|
|
|
|
<b>aborts</b>
|
|
- angularStretchAtOneNormTorque < sqrt(eps)
|
|
- stiffnessAtOneNormTorque < 1.1/angularStretchAtOneNormTorque
|
|
- normTorqueAtToeEnd < sqrt(eps) or normTorqueAtToeEnd > 0.99
|
|
- curviness < 0 or curviness > 1
|
|
|
|
*/
|
|
static void createTendonTorqueAngleCurve(
|
|
double angularStretchAtOneNormTorque,
|
|
double stiffnessAtOneNormTorque,
|
|
double normTorqueAtToeEnd,
|
|
double curviness,
|
|
const std::string& curveName,
|
|
RigidBodyDynamics::Addons::Geometry::SmoothSegmentedFunction&
|
|
smoothSegmentedFunctionToUpdate
|
|
);
|
|
|
|
};
|
|
}
|
|
}
|
|
}
|
|
#endif //TORQUEMUSCLEFUNCTIONFACTORY_H_
|