CKinematicChain.cpp

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2020, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */

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

#include <mrpt/kinematics/CKinematicChain.h>
#include <mrpt/opengl/CCylinder.h>
#include <mrpt/opengl/CSetOfObjects.h>
#include <mrpt/opengl/stock_objects.h>
#include <mrpt/serialization/CArchive.h>
#include <mrpt/serialization/stl_serialization.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.emplace_back(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(
    std::vector<mrpt::poses::CPose3D>& poses,
    [[maybe_unused]] const mrpt::poses::CPose3D& pose0) const
{
    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 CVectorFixedDouble<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::opengl::CCylinder::Create(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::opengl::CCylinder::Create(R, R, -a);
    gl_cyl2->setColor_u8(mrpt::img::TColor(0xff, 0x00, 0x00));
    gl_cyl2->setPose(mrpt::poses::CPose3D(0, 0, 0, 0, 90.0_deg, 0));
    gl_cyl2->setName("cyl.a");

    objs->insert(gl_cyl2);
}

void CKinematicChain::getAs3DObject(
    mrpt::opengl::CSetOfObjects::Ptr& obj,
    std::vector<mrpt::poses::CPose3D>* out_all_poses) const
{
    ASSERT_(obj);
    const size_t N = m_links.size();

    // Recompute current poses:
    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(
    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:
    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 float d = mrpt::d2f(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 float a = mrpt::d2f(m_links[i - 1].a);
            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;
}