DynamicsHelper.cpp

/*
 * This file is part of ArmarX.
 *
 * Copyright (C) 2011-2017, High Performance Humanoid Technologies (H2T), Karlsruhe Institute of Technology (KIT), all rights reserved.
 *
 * ArmarX is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * ArmarX 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 *
 * @package    ArmarX
 * @author     Mirko Waechter( mirko.waechter at kit dot edu)
 * @date       2019
 * @copyright  http://www.gnu.org/licenses/gpl-2.0.txt
 *             GNU General Public License
 */
#include "DynamicsHelper.h"

#include <VirtualRobot/Dynamics/Dynamics.h>
#include <VirtualRobot/RobotNodeSet.h>

#include <ArmarXCore/core/exceptions/local/ExpressionException.h>
#include <ArmarXCore/observers/filters/rtfilters/RTFilterBase.h>

#include <RobotAPI/components/units/RobotUnit/RobotUnit.h>

namespace armarx
{

    DynamicsHelper::DynamicsHelper(RobotUnit* robotUnit) : robotUnit(robotUnit)
    {

        ARMARX_CHECK_EXPRESSION(robotUnit);
    }

    void
    DynamicsHelper::addRobotPart(VirtualRobot::RobotNodeSetPtr rnsJoints,
                                 VirtualRobot::RobotNodeSetPtr rnsBodies,
                                 rtfilters::RTFilterBasePtr velocityFilter,
                                 rtfilters::RTFilterBasePtr accelerationFilter)
    {
        DynamicsData data(rnsJoints, rnsBodies);
        for (size_t i = 0; i < rnsJoints->getSize(); i++)
        {
            auto selectedJoint = robotUnit->getSensorDevice(rnsJoints->getNode(i)->getName());
            if (selectedJoint)
            {
                auto sensorValue = const_cast<SensorValue1DoFActuator*>(
                    selectedJoint->getSensorValue()->asA<SensorValue1DoFActuator>());
                ARMARX_CHECK_EXPRESSION(sensorValue) << rnsJoints->getNode(i)->getName();
                ARMARX_DEBUG << "will calculate inverse dynamics for robot node "
                             << rnsJoints->getNode(i)->getName();
                data.nodeSensorVec.push_back(std::make_pair(rnsJoints->getNode(i), sensorValue));
            }
            else
            {
                ARMARX_INFO << "Joint " << rnsJoints->getNode(i)->getName() << " not found";
                data.nodeSensorVec.push_back(std::make_pair(rnsJoints->getNode(i), nullptr));
            }
            if (velocityFilter)
            {
                data.velocityFilter.push_back(velocityFilter->clone());
            }
            if (accelerationFilter)
            {
                data.accelerationFilter.push_back(accelerationFilter->clone());
            }
        }
        dataMap.emplace(std::make_pair(rnsJoints, data));
    }

    void
    DynamicsHelper::update(const IceUtil::Time& sensorValuesTimestamp,
                           const IceUtil::Time& timeSinceLastIteration)
    {
        for (auto& pair : dataMap)
        {
            // first get current state of the robot (position, velocity, acceleration)
            auto& data = pair.second;
            auto& dynamics = data.dynamics;
            {
                size_t i = 0;
                for (auto& node : data.nodeSensorVec)
                {
                    ARMARX_CHECK_EXPRESSION(node.second) << node.first->getName();
                    data.q(i) = node.second->position;
                    if (i < data.velocityFilter.size() && data.velocityFilter.at(i) &&
                        !std::isnan(node.second->velocity))
                    {
                        data.qDot(i) = data.velocityFilter.at(i)->update(sensorValuesTimestamp,
                                                                         node.second->velocity);
                    }
                    else
                    {
                        data.qDot(i) = node.second->velocity;
                    }
                    if (i < data.accelerationFilter.size() && data.accelerationFilter.at(i) &&
                        !std::isnan(node.second->acceleration))
                    {
                        data.qDDot(i) = data.accelerationFilter.at(i)->update(
                            sensorValuesTimestamp, node.second->acceleration);
                    }
                    else
                    {
                        data.qDDot(i) = node.second->acceleration;
                    }
                    i++;
                }
            }
            // calculate external torques (tau) applied to robot induced by dynamics
            dynamics.getGravityMatrix(data.q, data.tauGravity);
            dynamics.getInverseDynamics(data.q, data.qDot, data.qDDot, data.tau);
            // update virtual sensor values
            size_t i = 0;
            for (auto& node : data.nodeSensorVec)
            {
                auto torque = data.tau(i);
                auto gravityTorque = data.tauGravity(i);
                if (node.second)
                {
                    node.second->inverseDynamicsTorque = -torque;
                    node.second->gravityTorque = -gravityTorque;
                    node.second->inertiaTorque = -(torque - gravityTorque);
                }
                i++;
            }
        }
    }

    DynamicsHelper::DynamicsData::DynamicsData(VirtualRobot::RobotNodeSetPtr rnsJoints,
                                               VirtualRobot::RobotNodeSetPtr rnsBodies) :
        rnsJoints(rnsJoints), rnsBodies(rnsBodies), dynamics(rnsJoints, rnsBodies)
    {
        q = qDot = qDDot = tau = tauGravity = Eigen::VectorXd::Zero(rnsJoints->getSize());
    }
} // namespace armarx