PPDMassProperties.cpp

Go to the documentation of this file.

/*******************************************************************************
 Copyright (c) 2020, Fabio Muratore, Honda Research Institute Europe GmbH, and
 Technical University of Darmstadt.
 All rights reserved.

 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are met:
 1. Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
 2. Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in the
    documentation and/or other materials provided with the distribution.
 3. Neither the name of Fabio Muratore, Honda Research Institute Europe GmbH,
    or Technical University of Darmstadt, nor the names of its contributors may
    be used to endorse or promote products derived from this software without
    specific prior written permission.

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 DISCLAIMED. IN NO EVENT SHALL FABIO MURATORE, HONDA RESEARCH INSTITUTE EUROPE GMBH,
 OR TECHNICAL UNIVERSITY OF DARMSTADT BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
 IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
*******************************************************************************/

#include "PPDMassProperties.h"
#include "PPDSingleVar.h"

#include <Rcs_typedef.h>
#include <Rcs_body.h>
#include <Rcs_shape.h>
#include <Rcs_math.h>

namespace Rcs
{

#define DEF_MASS_PARAM(name, modflag, var) \
    addChild(new PPDSingleVar<double>((name), (modflag), [](BodyParamInfo& bpi) -> double& {return (var);}))

PPDMassProperties::PPDMassProperties()
{
    DEF_MASS_PARAM("mass", BodyParamInfo::MOD_MASS, bpi.body->m);
    
    DEF_MASS_PARAM("com_x", BodyParamInfo::MOD_COM, bpi.body->Inertia->org[0]);
    DEF_MASS_PARAM("com_y", BodyParamInfo::MOD_COM, bpi.body->Inertia->org[1]);
    DEF_MASS_PARAM("com_z", BodyParamInfo::MOD_COM, bpi.body->Inertia->org[2]);
    
    DEF_MASS_PARAM("i_xx", BodyParamInfo::MOD_INERTIA, bpi.body->Inertia->rot[0][0]);
    DEF_MASS_PARAM("i_xy", BodyParamInfo::MOD_INERTIA, bpi.body->Inertia->rot[0][1]);
    DEF_MASS_PARAM("i_xz", BodyParamInfo::MOD_INERTIA, bpi.body->Inertia->rot[0][2]);
    DEF_MASS_PARAM("i_yy", BodyParamInfo::MOD_INERTIA, bpi.body->Inertia->rot[1][1]);
    DEF_MASS_PARAM("i_yz", BodyParamInfo::MOD_INERTIA, bpi.body->Inertia->rot[1][2]);
    DEF_MASS_PARAM("i_zz", BodyParamInfo::MOD_INERTIA, bpi.body->Inertia->rot[2][2]);
}

PPDMassProperties::~PPDMassProperties() = default;


void PPDMassProperties::setValues(PropertySource* inValues)
{
    PPDCompound::setValues(inValues);
    
    if (bodyParamInfo->body->m == 0.0) {
        return;
    }
    double v_bdy = RcsBody_computeVolume(bodyParamInfo->body);
    if (v_bdy == 0.0) {
        return;
    }
    
    if (!bodyParamInfo->isChanged(BodyParamInfo::MOD_COM)) {
        // Recompute the CoM from the shape since that function is not exported
        Vec3d_setZero(bodyParamInfo->body->Inertia->org);
        
        RCSBODY_TRAVERSE_SHAPES(bodyParamInfo->body) {
            double r_com_sh[3], v_sh;
            v_sh = RcsShape_computeVolume(SHAPE);
            RcsShape_computeLocalCOM(SHAPE, r_com_sh);
            Vec3d_constMulSelf(r_com_sh, v_sh/v_bdy);
            Vec3d_addSelf(bodyParamInfo->body->Inertia->org, r_com_sh);
        }
    }
    
    if (!bodyParamInfo->isChanged(BodyParamInfo::MOD_INERTIA)) {
        Mat3d_setZero(bodyParamInfo->body->Inertia->rot);
        // Recompute the inertia from shapes using existing COM
        double density = bodyParamInfo->body->m/v_bdy;   // Density: rho = m / V
        
        RCSBODY_TRAVERSE_SHAPES(bodyParamInfo->body) {
            // Compute the shape's inertia around its COM (it is represented in the shape's frame of reference)
            double I_s[3][3];
            RcsShape_computeInertiaTensor(SHAPE, density, I_s);
            
            // Rotate inertia tensor from the shape frame into the body frame:
            // B_I = A_BC^T C_I A_CB
            Mat3d_similarityTransform(I_s, (double (*)[3]) SHAPE->A_CB.rot, I_s);
            
            // Add the Steiner term related to gravity center of shape in body frame
            double r_b_sgc[3];   // vector from body origin to shape gravity center
            RcsShape_computeLocalCOM(SHAPE, r_b_sgc);
            double r_sgc_bgc[3];   // vector from shape COM to body COM
            Vec3d_sub(r_sgc_bgc, bodyParamInfo->body->Inertia->org, r_b_sgc);
            double m_sh = density*RcsShape_computeVolume(SHAPE);
            Math_addSteinerToInertia(I_s, r_sgc_bgc, m_sh);
            Mat3d_addSelf(bodyParamInfo->body->Inertia->rot, I_s);
        }
    }
    else {
        // Fill up symmetric elements of inertia
        bodyParamInfo->body->Inertia->rot[1][0] = bodyParamInfo->body->Inertia->rot[0][1];
        bodyParamInfo->body->Inertia->rot[2][0] = bodyParamInfo->body->Inertia->rot[0][2];
        bodyParamInfo->body->Inertia->rot[2][1] = bodyParamInfo->body->Inertia->rot[1][2];
    }
}

} /* namespace Rcs */