CKinematicChain.cpp

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/* +---------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)               |
   |                          http://www.mrpt.org/                             |
   |                                                                           |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file        |
   | See: http://www.mrpt.org/Authors - All rights reserved.                   |
   | Released under BSD License. See details in http://www.mrpt.org/License    |
   +---------------------------------------------------------------------------+ */

#include "kinematics-precomp.h"  // Precompiled headers

#include <mrpt/kinematics/CKinematicChain.h>
#include <mrpt/utils/CStream.h>
#include <mrpt/utils/stl_serialization.h>
#include <mrpt/opengl/CSetOfObjects.h>
#include <mrpt/opengl/CCylinder.h>
#include <mrpt/opengl/stock_objects.h>

using namespace mrpt;
using namespace mrpt::math;
using namespace mrpt::utils;
using namespace mrpt::poses;
using namespace mrpt::kinematics;
using namespace std;

IMPLEMENTS_SERIALIZABLE(CKinematicChain, CSerializable, mrpt::kinematics)


/** Appends a new link to the robotic arm, with the given Denavit-Hartenberg parameters (see TKinematicLink for further details) */
void CKinematicChain::addLink(double theta, double d, double a, double alpha, bool is_prismatic)
{
        m_links.push_back( TKinematicLink(theta,d,a,alpha,is_prismatic) );
}

/** Removes one link from the kinematic chain (0<=idx<N) */
void CKinematicChain::removeLink(const size_t idx)
{
        ASSERT_BELOW_(idx,m_links.size())
        m_links.erase(m_links.begin()+idx);
}

const TKinematicLink& CKinematicChain::getLink(const size_t idx) const
{
        ASSERT_BELOW_(idx,m_links.size())
        return m_links[idx];
}

TKinematicLink& CKinematicChain::getLinkRef(const size_t idx)
{
        ASSERT_BELOW_(idx,m_links.size())
        return m_links[idx];
}

void CKinematicChain::setOriginPose(const mrpt::poses::CPose3D &new_pose)
{
        m_origin = new_pose;
}

const mrpt::poses::CPose3D &CKinematicChain::getOriginPose() const
{
        return m_origin;
}

/*---------------------------------------------------------------
   Implements the writing to a CStream capability of CSerializable objects
  ---------------------------------------------------------------*/
void  CKinematicChain::writeToStream(mrpt::utils::CStream &out,int *version) const
{
        if (version)
                *version = 1;
        else
        {
                out << m_links << m_origin;
        }
}

/*---------------------------------------------------------------
        Implements the reading from a CStream capability of CSerializable objects
  ---------------------------------------------------------------*/
void  CKinematicChain::readFromStream(mrpt::utils::CStream &in,int version)
{
        switch(version)
        {
        case 0:
        case 1:
                {
                        in >> m_links;
                        if (version>=1)
                        {
                                in >> m_origin;
                        }
                        else m_origin=mrpt::poses::CPose3D();
                } break;
        default:
                MRPT_THROW_UNKNOWN_SERIALIZATION_VERSION(version)
        };
}

/** Go thru all the links of the chain and compute the global pose of each link. The "ground" link pose "pose0" defaults to the origin of coordinates,
        * but anything else can be passed as the optional argument. */
void CKinematicChain::recomputeAllPoses(mrpt::aligned_containers<mrpt::poses::CPose3D>::vector_t & poses,
        const mrpt::poses::CPose3D & pose0 )const
{
        MRPT_UNUSED_PARAM(pose0);
        const size_t N=m_links.size();

        poses.resize(N+1);

        CPose3D p = m_origin;  // Cummulative pose

        poses[0] = p;

        for (size_t i=0;i<N;i++)
        {
                // Build the 3D pose change of the i'th link:
                const double th = m_links[i].theta;
                const double alpha = m_links[i].alpha;
                const double d = m_links[i].d;
                const double a = m_links[i].a;

                const double t_vals[3] = {
                        a * cos(th),
                        a * sin(th),
                        d };
                const double r_vals[3*3] = {
                        cos(th), -sin(th)*cos(alpha), sin(th)*sin(alpha),
                        sin(th), cos(th)*cos(alpha), -cos(th)*sin(alpha),
                        0, sin(alpha), cos(alpha) };

                const CMatrixDouble33 R(r_vals);
                const CArrayDouble<3> t(t_vals);

                CPose3D link(R,t);

                p.composeFrom(p,link);

                poses[i+1] = p;
        }
}

const float R = 0.01f;

void addBar_D(mrpt::opengl::CSetOfObjectsPtr &objs, const double d)
{

        mrpt::opengl::CCylinderPtr gl_cyl = mrpt::opengl::CCylinder::Create(R,R, d );
        gl_cyl->setColor_u8( mrpt::utils::TColor(0x00,0x00,0xff) );
        gl_cyl->setName("cyl.d");

        objs->insert(gl_cyl);
}

void addBar_A(mrpt::opengl::CSetOfObjectsPtr &objs, const double a)
{
        mrpt::opengl::CCylinderPtr gl_cyl2 = mrpt::opengl::CCylinder::Create(R,R, -a );
        gl_cyl2->setColor_u8( mrpt::utils::TColor(0xff,0x00,0x00) );
        gl_cyl2->setPose( mrpt::poses::CPose3D(0,0,0, 0, DEG2RAD(90),0) );
        gl_cyl2->setName("cyl.a");

        objs->insert(gl_cyl2);
}

void CKinematicChain::getAs3DObject(
        mrpt::opengl::CSetOfObjectsPtr &obj,
        mrpt::aligned_containers<mrpt::poses::CPose3D>::vector_t *out_all_poses
        ) const
{
        ASSERT_(obj.present())
        const size_t N=m_links.size();

        // Recompute current poses:
        mrpt::aligned_containers<mrpt::poses::CPose3D>::vector_t all_poses;
        recomputeAllPoses( all_poses );

        m_last_gl_objects.resize(N+1);

        // Ground [0] and Links [1-N]:
        for (size_t i=0;i<=N;i++)
        {
                mrpt::opengl::CSetOfObjectsPtr gl_corner = mrpt::opengl::stock_objects::CornerXYZSimple( 0.1f, 3.0f );
                gl_corner->setPose( all_poses[i] );

                gl_corner->setName( mrpt::format("%u",static_cast<unsigned int>(i)) );
                gl_corner->enableShowName();

                if (i<N) addBar_D(gl_corner,m_links[i].d);
                if (i>0) addBar_A(gl_corner,m_links[i-1].a);

                obj->insert(gl_corner);
                m_last_gl_objects[i] = gl_corner;
        }

        if (out_all_poses)
                out_all_poses->swap(all_poses);
}

void CKinematicChain::update3DObject(mrpt::aligned_containers<mrpt::poses::CPose3D>::vector_t *out_all_poses ) const
{
        ASSERTMSG_((m_links.size()+1)==m_last_gl_objects.size(), "The kinematic chain has changed since the last call to getAs3DObject()")

        const size_t N=m_links.size();

        // Recompute current poses:
        mrpt::aligned_containers<mrpt::poses::CPose3D>::vector_t all_poses;
        recomputeAllPoses( all_poses );

        for (size_t i=0;i<=N;i++)
        {
                mrpt::opengl::CSetOfObjectsPtr gl_objs = mrpt::opengl::CSetOfObjectsPtr(m_last_gl_objects[i]);
                gl_objs->setPose( all_poses[i] );

                if (i<N)
                {
                        mrpt::opengl::CCylinderPtr glCyl = mrpt::opengl::CCylinderPtr( gl_objs->getByName("cyl.d") );
                        const double d = m_links[i].d;
                        glCyl->setHeight( d );
                }

                if (i>0)
                {
                        mrpt::opengl::CCylinderPtr glCyl2 = mrpt::opengl::CCylinderPtr( gl_objs->getByName("cyl.a") );
                        const double a = m_links[i-1].a;
                        //glCyl2->setPose( mrpt::poses::CPose3D(0,0,d, 0, DEG2RAD(90),0) );
                        glCyl2->setHeight( -a );
                }
        }

        if (out_all_poses)
                out_all_poses->swap(all_poses);
}

/** Erases all links and leave the robot arm empty. */
void CKinematicChain::clear()
{
        m_links.clear();
        m_last_gl_objects.clear();
}


mrpt::utils::CStream & mrpt::kinematics::operator>>(mrpt::utils::CStream &in,TKinematicLink &o)
{
        uint32_t version;
        in >> version;
        switch(version)
        {
        case 0:
                in >> o.theta >> o.d >> o.a >> o.alpha >> o.is_prismatic;
                break;
        default:
                MRPT_THROW_UNKNOWN_SERIALIZATION_VERSION(version)
        }
        return in;
}
mrpt::utils::CStream & mrpt::kinematics::operator<<(mrpt::utils::CStream &out,const TKinematicLink &o)
{
        const uint32_t version = 0;
        out << version;
        out << o.theta << o.d << o.a << o.alpha << o.is_prismatic;
        return out;
}