CKinematicChain.cpp

Go to the documentation of this file.

/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2018, 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/serialization/CArchive.h>
#include <mrpt/serialization/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::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;
}
 
uint8_t CKinematicChain::serializeGetVersion() const { return 1; }
void CKinematicChain::serializeTo(mrpt::serialization::CArchive& out) const
{
        out << m_links << m_origin;
}
 
void CKinematicChain::serializeFrom(
        mrpt::serialization::CArchive& in, uint8_t 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_std_vector<mrpt::poses::CPose3D>& 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::CSetOfObjects::Ptr& objs, const double d)
{
        mrpt::opengl::CCylinder::Ptr gl_cyl =
                mrpt::make_aligned_shared<mrpt::opengl::CCylinder>(R, R, d);
        gl_cyl->setColor_u8(mrpt::img::TColor(0x00, 0x00, 0xff));
        gl_cyl->setName("cyl.d");
 
        objs->insert(gl_cyl);
}
 
void addBar_A(mrpt::opengl::CSetOfObjects::Ptr& objs, const double a)
{
        mrpt::opengl::CCylinder::Ptr gl_cyl2 =
                mrpt::make_aligned_shared<mrpt::opengl::CCylinder>(R, R, -a);
        gl_cyl2->setColor_u8(mrpt::img::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::CSetOfObjects::Ptr& obj,
        mrpt::aligned_std_vector<mrpt::poses::CPose3D>* out_all_poses) const
{
        ASSERT_(obj);
        const size_t N = m_links.size();
 
        // Recompute current poses:
        mrpt::aligned_std_vector<mrpt::poses::CPose3D> 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::CSetOfObjects::Ptr 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_std_vector<mrpt::poses::CPose3D>* 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_std_vector<mrpt::poses::CPose3D> all_poses;
        recomputeAllPoses(all_poses);
 
        for (size_t i = 0; i <= N; i++)
        {
                mrpt::opengl::CSetOfObjects::Ptr gl_objs =
                        std::dynamic_pointer_cast<mrpt::opengl::CSetOfObjects>(
                                m_last_gl_objects[i]);
                gl_objs->setPose(all_poses[i]);
 
                if (i < N)
                {
                        mrpt::opengl::CCylinder::Ptr glCyl =
                                std::dynamic_pointer_cast<mrpt::opengl::CCylinder>(
                                        gl_objs->getByName("cyl.d"));
                        const double d = m_links[i].d;
                        glCyl->setHeight(d);
                }
 
                if (i > 0)
                {
                        mrpt::opengl::CCylinder::Ptr glCyl2 =
                                std::dynamic_pointer_cast<mrpt::opengl::CCylinder>(
                                        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::serialization::CArchive& mrpt::kinematics::operator>>(
        mrpt::serialization::CArchive& 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::serialization::CArchive& mrpt::kinematics::operator<<(
        mrpt::serialization::CArchive& 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;
}