fk.cpp

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/*
 * Copyright (c) 2008, AIST, the University of Tokyo and General Robotix Inc.
 * All rights reserved. This program is made available under the terms of the
 * Eclipse Public License v1.0 which accompanies this distribution, and is
 * available at http://www.eclipse.org/legal/epl-v10.html
 * Contributors:
 * The University of Tokyo
 */
/*
 * fk.cpp
 * Create: Katsu Yamane, Univ. of Tokyo, 03.06.19
 */
 
#include "chain.h"
 
void Chain::CalcPosition()
{
        root->calc_position();
}
 
void Joint::calc_position()
{
        if(parent)
        {
#if 0
                // readable, but slower version
                abs_pos = parent->abs_pos + parent->abs_att * rel_pos;
                abs_att = parent->abs_att * rel_att;
#else
                // faster version
                abs_pos.mul(parent->abs_att, rel_pos);
                abs_pos += parent->abs_pos;
                abs_att.mul(parent->abs_att, rel_att);
#endif
//              cout << name << ": " << abs_pos << endl;
        }
        child->calc_position();
        brother->calc_position();
}
 
void Chain::CalcVelocity()
{
        root->calc_velocity();
}
 
void Joint::calc_velocity()
{
        if(parent)
        {
                static fMat33 t_rel_att;
                static fVec3 v1, v2;
                t_rel_att.tran(rel_att);
                // compute loc_lin_vel
                v1.cross(parent->loc_ang_vel, rel_pos);
                v2.mul(t_rel_att, parent->loc_lin_vel);
                loc_lin_vel.mul(t_rel_att, v1);
                loc_lin_vel += v2;
                loc_lin_vel += rel_lin_vel;
                // compute loc_ang_vel
                loc_ang_vel.mul(t_rel_att, parent->loc_ang_vel);
                loc_ang_vel += rel_ang_vel;
                // compute loc_com_vel
                v1.cross(loc_ang_vel, loc_com);
                loc_com_vel.add(loc_lin_vel, v1);
        }
        else
        {
                loc_lin_vel.zero();
                loc_ang_vel.zero();
        }
        child->calc_velocity();
        brother->calc_velocity();
}
 
void Chain::CalcAcceleration()
{
        root->calc_acceleration();
}
 
void Joint::calc_acceleration()
{
        if(parent)
        {
                static fMat33 t_rel_att;
                static fVec3 v1, v2, v3, v4;
                t_rel_att.tran(rel_att);
                // Éð»Ê±ñ1¡¦x
                v1.mul(t_rel_att, parent->loc_ang_vel);
//              v1 += loc_ang_vel;
                v1 *= 2.0;
                v2.cross(v1, rel_lin_vel);
                loc_lin_acc.add(rel_lin_acc, v2);
                v2.cross(parent->loc_ang_acc, rel_pos);
                v1.add(parent->loc_lin_acc, v2);
                v2.cross(parent->loc_ang_vel, rel_pos);
                v3.cross(parent->loc_ang_vel, v2);
                v1 += v3;
                v4.mul(t_rel_att, v1);
                loc_lin_acc += v4;
                // ³Ñ±ñ1¡¦x
//              v1.cross(loc_ang_vel, parent->rel_ang_vel);
                v1.cross(loc_ang_vel, rel_ang_vel);
                loc_ang_acc.add(rel_ang_acc, v1);
                v1.mul(t_rel_att, parent->loc_ang_acc);
                loc_ang_acc += v1;
                // ½Å¿´£öÅð»Ê±ñ1¡¦x
                v1.cross(loc_ang_acc, loc_com);
                loc_com_acc.add(loc_lin_acc, v1);
                v1.cross(loc_ang_vel, loc_com);
                v2.cross(loc_ang_vel, v1);
                loc_com_acc += v2;
 
//              cerr << name << ": loc_lin_acc = " << loc_lin_acc << endl;
//              cerr << name << ": loc_ang_acc = " << loc_ang_acc << endl;
//              if(real)
//                      cerr << name << ": acc = " << abs_att*loc_lin_acc << abs_att*loc_ang_acc << endl;
        }
        else
        {
                // ¥ë¡¼¥È¥ê¥ó¥¯
                // loc_lin_acc£õ"¡¦dÍ÷)¡¦¡¦x£åÂð€¡¦Ãà¡à¡¦Ëࡦ±êù硦¡¦Çà
                loc_ang_acc.zero();
                loc_com_acc.zero();
        }
        child->calc_acceleration();
        brother->calc_acceleration();
}
 
double Chain::TotalCOM(fVec3& com, const char* chname)
{
        com.zero();
        double m = root->total_com(com, chname);
        com /= m;
        return m;
}
 
double Joint::total_com(fVec3& com, const char* chname)
{
        int is_target = false;
        if(!chname)
        {
                is_target = true;
        }
        else
        {
                char* my_chname = CharName();
                if(my_chname && !strcmp(my_chname, chname))
                {
                        is_target = true;
                }
        }
        fVec3 b_com, c_com;
        b_com.zero();
        c_com.zero();
        double ret = brother->total_com(b_com, chname) + child->total_com(c_com, chname);
 
        com.add(b_com, c_com);
        if(is_target)
        {
                static fVec3 abs_com_pos, my_com;
                ret += mass;
                abs_com_pos.mul(abs_att, loc_com);
                abs_com_pos += abs_pos;
                my_com.mul(abs_com_pos, mass);
                com += my_com;
        }
        return ret;
}