joint_trajectory_action_controller.cpp

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/*
    Copyright (c) 2011, Antons Rebguns <email>
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are met:
        * Redistributions of source code must retain the above copyright
        notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above copyright
        notice, this list of conditions and the following disclaimer in the
        documentation and/or other materials provided with the distribution.
        * Neither the name of the <organization> nor the
        names of its contributors may be used to endorse or promote products
        derived from this software without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY Antons Rebguns <email> ''AS IS'' AND ANY
    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    DISCLAIMED. IN NO EVENT SHALL Antons Rebguns <email> BE LIABLE FOR ANY
    DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
    (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
    ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <sstream>
#include <string>
#include <vector>
#include <XmlRpcValue.h>

#include <dynamixel_hardware_interface/dynamixel_const.h>
#include <dynamixel_hardware_interface/dynamixel_io.h>

#include <dynamixel_hardware_interface/single_joint_controller.h>
#include <dynamixel_hardware_interface/multi_joint_controller.h>
#include <dynamixel_hardware_interface/joint_trajectory_action_controller.h>
#include <dynamixel_hardware_interface/JointState.h>

#include <ros/ros.h>
#include <pluginlib/class_list_macros.h>
#include <trajectory_msgs/JointTrajectory.h>
#include <control_msgs/FollowJointTrajectoryAction.h>

PLUGINLIB_DECLARE_CLASS(dynamixel_hardware_interface,
                        JointTrajectoryActionController,
                        controller::JointTrajectoryActionController,
                        controller::MultiJointController)

namespace controller
{

JointTrajectoryActionController::JointTrajectoryActionController()
{
    terminate_ = false;
}

JointTrajectoryActionController::~JointTrajectoryActionController()
{
}

bool JointTrajectoryActionController::initialize(std::string name, std::vector<SingleJointController*> deps)
{
    if (!MultiJointController::initialize(name, deps)) { return false; }

    update_rate_ = 1000;
    state_update_rate_ = 50;
    
    std::string prefix = "joint_trajectory_action_node/constraints/";
    
    c_nh_.param<double>(prefix + "goal_time", goal_time_constraint_, 0.0);
    c_nh_.param<double>(prefix + "stopped_velocity_tolerance", stopped_velocity_tolerance_, 0.01);
    c_nh_.param<double>("joint_trajectory_action_node/min_velocity", min_velocity_, 0.1);
    
    goal_constraints_.resize(num_joints_);
    trajectory_constraints_.resize(num_joints_);
    
    for (size_t i = 0; i < num_joints_; ++i)
    {
        c_nh_.param<double>(prefix + joint_names_[i] + "/goal", goal_constraints_[i], -1.0);
        c_nh_.param<double>(prefix + joint_names_[i] + "/trajectory", trajectory_constraints_[i], -1.0);
    }
    
    msg_.joint_names = joint_names_;
    msg_.desired.positions.resize(num_joints_);
    msg_.desired.velocities.resize(num_joints_);
    msg_.desired.accelerations.resize(num_joints_);
    msg_.actual.positions.resize(num_joints_);
    msg_.actual.velocities.resize(num_joints_);
    msg_.actual.accelerations.resize(num_joints_);
    msg_.error.positions.resize(num_joints_);
    msg_.error.velocities.resize(num_joints_);
    msg_.error.accelerations.resize(num_joints_);
    
    return true;
}

void JointTrajectoryActionController::start()
{
    command_sub_ = c_nh_.subscribe("command", 50, &JointTrajectoryActionController::processCommand, this);
    state_pub_ = c_nh_.advertise<control_msgs::FollowJointTrajectoryFeedback>("state", 50);
    
    action_server_.reset(new FJTAS(c_nh_, "follow_joint_trajectory",
                                   boost::bind(&JointTrajectoryActionController::processFollowTrajectory, this, _1),
                                   false));
    action_server_->start();
    feedback_thread_ = new boost::thread(boost::bind(&JointTrajectoryActionController::updateState, this));
}

void JointTrajectoryActionController::stop()
{
    {
        boost::mutex::scoped_lock terminate_lock(terminate_mutex_);
        terminate_ = true;
    }
    
    feedback_thread_->join();
    delete feedback_thread_;
    
    command_sub_.shutdown();
    state_pub_.shutdown();
    action_server_->shutdown();
}

void JointTrajectoryActionController::processCommand(const trajectory_msgs::JointTrajectoryConstPtr& msg)
{
    if (action_server_->isActive()) { action_server_->setPreempted(); }
    
    while (action_server_->isActive())
    {
        ros::Duration(0.01).sleep();
    }
        
    processTrajectory(*msg, false);
}

void JointTrajectoryActionController::processFollowTrajectory(const control_msgs::FollowJointTrajectoryGoalConstPtr& goal)
{
    processTrajectory(goal->trajectory, true);
}

void JointTrajectoryActionController::updateState()
{
    ros::Rate rate(state_update_rate_);
    
    while (nh_.ok())
    {
        {
            boost::mutex::scoped_lock terminate_lock(terminate_mutex_);
            if (terminate_) { break; }
        }
        
        msg_.header.stamp = ros::Time::now();
        
        for (size_t j = 0; j < joint_names_.size(); ++j)
        {
            const dynamixel_hardware_interface::JointState* state = joint_states_[joint_names_[j]];
            msg_.desired.positions[j] = state->target_position;
            msg_.desired.velocities[j] = std::abs(state->target_velocity);
            msg_.actual.positions[j] = state->position;
            msg_.actual.velocities[j] = std::abs(state->velocity);
            msg_.error.positions[j] = msg_.actual.positions[j] - msg_.desired.positions[j];
            msg_.error.velocities[j] = msg_.actual.velocities[j] - msg_.desired.velocities[j];
        }

        state_pub_.publish(msg_);
        rate.sleep();
    }
}

void JointTrajectoryActionController::processTrajectory(const trajectory_msgs::JointTrajectory& traj, bool is_action)
{
    control_msgs::FollowJointTrajectoryResult res;
    std::string error_msg;
    
    int num_points = traj.points.size();
    
    ROS_DEBUG("Received trajectory with %d points", num_points);
    
    // Maps from an index in joints_ to an index in the msg
    std::vector<int> lookup(num_joints_, -1);
    
    for (size_t j = 0; j < num_joints_; ++j)
    {
        for (size_t k = 0; k < traj.joint_names.size(); ++k)
        {
            if (traj.joint_names[k] == joint_names_[j])
            {
                lookup[j] = k;
                break;
            }
        }

        if (lookup[j] == -1)
        {
            res.error_code = control_msgs::FollowJointTrajectoryResult::INVALID_JOINTS;
            error_msg = "Unable to locate joint " + joint_names_[j] + " in the commanded trajectory";
            ROS_ERROR("%s", error_msg.c_str());
            if (is_action) { action_server_->setAborted(res, error_msg.c_str()); }
            return;
        }
    }
    
    std::vector<double> durations;//(num_points, 0.0);
    durations.resize(num_points);
    
    // find out the duration of each segment in the trajectory
    durations[0] = traj.points[0].time_from_start.toSec();
    double trajectory_duration = durations[0];
    
    for (int i = 1; i < num_points; ++i)
    {
        durations[i] = (traj.points[i].time_from_start - traj.points[i-1].time_from_start).toSec();
        trajectory_duration += durations[i];
        //ROS_DEBUG("tpi: %f, tpi-1: %f", traj.points[i].time_from_start.toSec(), traj.points[i-1].time_from_start.toSec());
        //ROS_DEBUG("i: %d, duration: %f, total: %f", i, durations[i], trajectory_duration);
    }
    
    if (traj.points[0].positions.empty())
    {
        res.error_code = control_msgs::FollowJointTrajectoryResult::INVALID_GOAL;
        error_msg = "First point of trajectory has no positions";
        ROS_ERROR("%s", error_msg.c_str());
        if (is_action) { action_server_->setAborted(res, error_msg); }
        return;
    }
    
    std::vector<Segment> trajectory;
    ros::Time time = ros::Time::now() + ros::Duration(0.01);

    for (int i = 0; i < num_points; ++i)
    {
        const trajectory_msgs::JointTrajectoryPoint point = traj.points[i];
        Segment seg;
        
        if (traj.header.stamp == ros::Time(0.0))
        {
            seg.start_time = (time + point.time_from_start).toSec() - durations[i];
        }
        else
        {
            seg.start_time = (traj.header.stamp + point.time_from_start).toSec() - durations[i];
        }
        
        seg.duration = durations[i];

        // Checks that the incoming segment has the right number of elements.
        if (!point.velocities.empty() && point.velocities.size() != num_joints_)
        {
            res.error_code = control_msgs::FollowJointTrajectoryResult::INVALID_GOAL;
            error_msg = "Command point " + boost::lexical_cast<std::string>(i) + " has " + boost::lexical_cast<std::string>(point.velocities.size()) + " elements for the velocities";
            ROS_ERROR("%s", error_msg.c_str());
            if (is_action) { action_server_->setAborted(res, error_msg); }
            return;
        }

        if (!point.positions.empty() && point.positions.size() != num_joints_)
        {
            res.error_code = control_msgs::FollowJointTrajectoryResult::INVALID_GOAL;
            error_msg = "Command point " + boost::lexical_cast<std::string>(i) + " has " + boost::lexical_cast<std::string>(point.positions.size()) + " elements for the positions";
            ROS_ERROR("%s", error_msg.c_str());
            if (is_action) { action_server_->setAborted(res, error_msg); }
            return;
        }
        
        seg.velocities.resize(num_joints_);
        seg.positions.resize(num_joints_);
        
        for (size_t j = 0; j < num_joints_; ++j)
        {
            seg.velocities[j] = point.velocities[lookup[j]];
            seg.positions[j] = point.positions[lookup[j]];
        }
        
        trajectory.push_back(seg);
    }
    
    ROS_INFO("Trajectory start requested at %.3lf, waiting...", traj.header.stamp.toSec());
    ros::Time::sleepUntil(traj.header.stamp);
    
    ros::Time end_time = traj.header.stamp + ros::Duration(trajectory_duration);
    std::vector<ros::Time> seg_end_times(num_points, ros::Time(0.0));
    
    for (int i = 0; i < num_points; ++i)
    {
        seg_end_times[i] = ros::Time(trajectory[i].start_time + durations[i]);
    }
    
    ROS_INFO("Trajectory start time is %.3lf, end time is %.3lf, total duration is %.3lf", time.toSec(), end_time.toSec(), trajectory_duration);

    trajectory_ = trajectory;
    ros::Time traj_start_time = ros::Time::now();
    ros::Rate rate(update_rate_);

    for (int seg = 0; seg < num_points; ++seg)
    {
        ROS_DEBUG("Processing segment %d", seg);
        
        // first point in trajectories calculated by OMPL is current position with duration of 0 seconds, skip it
        if (durations[seg] == 0.0)
        {
            ROS_DEBUG("Skipping segment %d becuase duration is 0", seg);
            continue;
        }
        
        std::map<std::string, std::vector<std::vector<int> > > multi_packet;
        
        std::map<std::string, std::vector<std::string> >::const_iterator pjit;
        std::vector<std::string>::const_iterator jit;
        
        for (pjit = port_to_joints_.begin(); pjit != port_to_joints_.end(); ++pjit)
        {
            std::vector<std::vector<int> > vals;
            
            for (jit = pjit->second.begin(); jit != pjit->second.end(); ++jit)
            {
                std::string joint = *jit;
                int j = joint_to_idx_[joint];
                
                double start_position = joint_states_[joint]->position;
                if (seg != 0) { start_position = trajectory[seg-1].positions[j]; }
                
                double desired_position = trajectory[seg].positions[j];
                double desired_velocity = std::max<double>(min_velocity_, std::abs(desired_position - start_position) / durations[seg]);
                
                ROS_DEBUG("\tstart_position: %f, duration: %f", start_position, durations[seg]);
                ROS_DEBUG("\tport: %s, joint: %s, dpos: %f, dvel: %f", pjit->first.c_str(), joint.c_str(), desired_position, desired_velocity);
                
                std::vector<std::vector<int> > mvcs = joint_to_controller_[joint]->getRawMotorCommands(desired_position, desired_velocity);
                for (size_t i = 0; i < mvcs.size(); ++i)
                {
                    vals.push_back(mvcs[i]);
                }
                
                multi_packet[pjit->first] = vals;
            }
        }
        
        std::map<std::string, std::vector<std::vector<int> > >::const_iterator mpit;
        for (mpit = multi_packet.begin(); mpit != multi_packet.end(); ++mpit)
        {
            port_to_io_[mpit->first]->setMultiPositionVelocity(mpit->second);
        }
        
        while (time < seg_end_times[seg])
        {
            // check if new trajectory was received, if so abort old one by setting the desired state to current state
            if (is_action && action_server_->isPreemptRequested())
            {
                res.error_code = control_msgs::FollowJointTrajectoryResult::SUCCESSFUL;
                error_msg = "New trajectory received. Aborting old trajectory.";
                
                std::map<std::string, std::vector<std::vector<int> > > multi_packet;

                std::map<std::string, std::vector<std::string> >::const_iterator pjit;
                std::vector<std::string>::const_iterator jit;
                
                for (pjit = port_to_joints_.begin(); pjit != port_to_joints_.end(); ++pjit)
                {
                    std::vector<std::vector<int> > vals;
                    
                    for (jit = pjit->second.begin(); jit != pjit->second.end(); ++jit)
                    {
                        std::string joint = *jit;
                        
                        double desired_position = joint_states_[joint]->position;
                        double desired_velocity = joint_states_[joint]->velocity;
                        
                        std::vector<std::vector<int> > mvcs = joint_to_controller_[joint]->getRawMotorCommands(desired_position, desired_velocity);
                        for (size_t i = 0; i < mvcs.size(); ++i)
                        {
                            vals.push_back(mvcs[i]);
                        }
                        
                        multi_packet[pjit->first] = vals;
                    }
                }
                
                std::map<std::string, std::vector<std::vector<int> > >::const_iterator mpit;
                for (mpit = multi_packet.begin(); mpit != multi_packet.end(); ++mpit)
                {
                    port_to_io_[mpit->first]->setMultiPositionVelocity(mpit->second);
                }
                
                action_server_->setPreempted(res, error_msg);
                ROS_WARN("%s", error_msg.c_str());
                return;
            }
            
            rate.sleep();
            time = ros::Time::now();
        }
        
        // Verifies trajectory constraints
        for (size_t j = 0; j < joint_names_.size(); ++j)
        {
            if (trajectory_constraints_[j] > 0.0 && msg_.error.positions[j] > trajectory_constraints_[j])
            {
                res.error_code = control_msgs::FollowJointTrajectoryResult::PATH_TOLERANCE_VIOLATED;
                error_msg = "Unsatisfied position constraint for " + joint_names_[j] +
                            " trajectory point " + boost::lexical_cast<std::string>(seg) +
                            ", " + boost::lexical_cast<std::string>(msg_.error.positions[j]) +
                            " is larger than " + boost::lexical_cast<std::string>(trajectory_constraints_[j]);
                ROS_ERROR("%s", error_msg.c_str());
                if (is_action) { action_server_->setAborted(res, error_msg); }
                return;
            }
        }
    }
    
    // let motors roll for specified amount of time
    ros::Duration(goal_time_constraint_).sleep();
    
    for (size_t i = 0; i < num_joints_; ++i)
    {
        if (goal_constraints_[i] > 0 && std::abs(msg_.error.positions[i]) > goal_constraints_[i])
        {
            res.error_code = control_msgs::FollowJointTrajectoryResult::GOAL_TOLERANCE_VIOLATED;
            error_msg = "Aborting because " + joint_names_[i] +
                        " joint wound up outside the goal constraints, " +
                        boost::lexical_cast<std::string>(msg_.error.positions[i]) +
                        " is larger than " + boost::lexical_cast<std::string>(goal_constraints_[i]);
            ROS_ERROR("%s", error_msg.c_str());
            if (is_action) { action_server_->setAborted(res, error_msg); }
            return;
        }
    }
    
    res.error_code = control_msgs::FollowJointTrajectoryResult::SUCCESSFUL;
    error_msg = "Trajectory execution successfully completed";
    ROS_INFO("%s", error_msg.c_str());
    action_server_->setSucceeded(res, error_msg);
}

}