joint.cpp

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// Copyright  (C)  2007  Ruben Smits <ruben dot smits at mech dot kuleuven dot be>
 
// Version: 1.0
// Author: Ruben Smits <ruben dot smits at mech dot kuleuven dot be>
// Maintainer: Ruben Smits <ruben dot smits at mech dot kuleuven dot be>
// URL: http://www.orocos.org/kdl
 
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
 
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
 
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 
#include "joint.hpp"
 
namespace KDL {
 
    Joint::Joint(const JointType& _type, const double& _scale, const double& _offset,
                 const double& _inertia, const double& _damping, const double& _stiffness):
        type(_type),scale(_scale),offset(_offset),inertia(_inertia),damping(_damping),stiffness(_stiffness)
    {
        // for sphere and swing, offset is not used, assume no offset
    }
 
    Joint::Joint(const Joint& in):
    type(in.type),scale(in.scale),offset(in.offset),
        inertia(in.inertia),damping(in.damping),stiffness(in.stiffness)
    {
    }
 
    Joint& Joint::operator=(const Joint& in)
    {
        type=in.type;
        scale=in.scale;
        offset=in.offset;
        inertia=in.inertia;
        damping=in.damping;
        stiffness=in.stiffness;
        return *this;
    }
 
 
    Joint::~Joint()
    {
    }
 
    Frame Joint::pose(const double* q)const
    {
 
        switch(type){
        case RotX:
            assert(q);
            return Frame(Rotation::RotX(scale*q[0]+offset));
            break;
        case RotY:
            assert(q);
            return  Frame(Rotation::RotY(scale*q[0]+offset));
            break;
        case RotZ:
            assert(q);
            return  Frame(Rotation::RotZ(scale*q[0]+offset));
            break;
        case TransX:
            assert(q);
            return  Frame(Vector(scale*q[0]+offset,0.0,0.0));
            break;
        case TransY:
            assert(q);
            return Frame(Vector(0.0,scale*q[0]+offset,0.0));
            break;
        case TransZ:
            assert(q);
            return Frame(Vector(0.0,0.0,scale*q[0]+offset));
            break;
        case Sphere:
            // the joint angles represent a rotation vector expressed in the base frame of the joint
            // (= the frame you get when there is no offset nor rotation)
            assert(q);
            return Frame(Rot(Vector(q[0], q[1], q[2])));
            break;
        case Swing:
            // the joint angles represent a 2D rotation vector in the XZ planee of the base frame of the joint
            // (= the frame you get when there is no offset nor rotation)
            assert(q);
            return Frame(Rot(Vector(q[0], 0.0, q[1])));
            break;
        default:
            return Frame::Identity();
            break;
        }
    }
 
    Twist Joint::twist(const double& qdot, int dof)const
    {
        switch(type){
        case RotX:
            return Twist(Vector(0.0,0.0,0.0),Vector(scale*qdot,0.0,0.0));
            break;
        case RotY:
            return Twist(Vector(0.0,0.0,0.0),Vector(0.0,scale*qdot,0.0));
            break;
        case RotZ:
            return Twist(Vector(0.0,0.0,0.0),Vector(0.0,0.0,scale*qdot));
            break;
        case TransX:
            return Twist(Vector(scale*qdot,0.0,0.0),Vector(0.0,0.0,0.0));
            break;
        case TransY:
            return Twist(Vector(0.0,scale*qdot,0.0),Vector(0.0,0.0,0.0));
            break;
        case TransZ:
            return Twist(Vector(0.0,0.0,scale*qdot),Vector(0.0,0.0,0.0));
            break;
        case Swing:
            switch (dof) {
            case 0:
                return Twist(Vector(0.0,0.0,0.0),Vector(scale*qdot,0.0,0.0));
            case 1:
                return Twist(Vector(0.0,0.0,0.0),Vector(0.0,0.0,scale*qdot));
            }
            return Twist::Zero();
        case Sphere:
            switch (dof) {
            case 0:
                return Twist(Vector(0.0,0.0,0.0),Vector(scale*qdot,0.0,0.0));
            case 1:
                return Twist(Vector(0.0,0.0,0.0),Vector(0.0,scale*qdot,0.0));
            case 2:
                return Twist(Vector(0.0,0.0,0.0),Vector(0.0,0.0,scale*qdot));
            }
            return Twist::Zero();
        default:
            return Twist::Zero();
            break;
        }
    }
 
    unsigned int Joint::getNDof() const
    {
        switch (type) {
        case Sphere:
            return 3;
        case Swing:
            return 2;
        case None:
            return 0;
        default:
            return 1;
        }
    }
 
} // end of namespace KDL