CWaypointsNavigator.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 "nav-precomp.h" // Precomp header

#include <mrpt/nav/reactive/CWaypointsNavigator.h>
#include <mrpt/poses/CPose2D.h>
#include <mrpt/math/wrap2pi.h>

using namespace mrpt::nav;
using namespace std;

std::string CWaypointsNavigator::TNavigationParamsWaypoints::getAsText() const
{
        std::string s = TNavigationParams::getAsText();
        if (!multiple_targets.empty())
        {
                s += "multiple_targets:\n";
                int i = 0;
                for (const auto &e : multiple_targets) {
                        s += mrpt::format("target[%i]:\n",i++);
                        s += e.getAsText();
                }
        }
        return s;
}

bool CWaypointsNavigator::TNavigationParamsWaypoints::isEqual(const CAbstractNavigator::TNavigationParamsBase& rhs) const
{
        auto o = dynamic_cast<const CWaypointsNavigator::TNavigationParamsWaypoints*>(&rhs);
        return o!=nullptr &&
            CAbstractNavigator::TNavigationParams::isEqual(rhs) &&
            multiple_targets == o->multiple_targets;
}

CWaypointsNavigator::CWaypointsNavigator(CRobot2NavInterface &robot_if) :
    CAbstractNavigator(robot_if),
    m_was_aligning(false),
    m_is_aligning(false),
    m_last_alignment_cmd(mrpt::system::now())
{
}

CWaypointsNavigator::~CWaypointsNavigator()
{
}

void CWaypointsNavigator::onNavigateCommandReceived()
{
        CAbstractNavigator::onNavigateCommandReceived();

        mrpt::synch::CCriticalSectionLocker csl(&m_nav_waypoints_cs);

        m_was_aligning = false;
        m_waypoint_nav_status = TWaypointStatusSequence();
        m_waypoint_nav_status.timestamp_nav_started = INVALID_TIMESTAMP;
        m_waypoint_nav_status.waypoint_index_current_goal = -1;  // Not started yet.
}

void CWaypointsNavigator::navigateWaypoints( const TWaypointSequence & nav_request )
{
        MRPT_START

        this->onNavigateCommandReceived();

        mrpt::synch::CCriticalSectionLocker csl(&m_nav_waypoints_cs);

        const size_t N = nav_request.waypoints.size();
        ASSERTMSG_(N>0,"List of waypoints is empty!");

        m_waypoint_nav_status.waypoints.resize(N);
        // Copy waypoints fields data, leave status fields to defaults:
        for (size_t i=0;i<N;i++)
        {
                ASSERT_( nav_request.waypoints[i].isValid() );
                m_waypoint_nav_status.waypoints[i] = nav_request.waypoints[i];
        }
        m_waypoint_nav_status.timestamp_nav_started = mrpt::system::now();

        // The main loop navigationStep() will iterate over waypoints and send them to navigate()
        MRPT_END
}

void CWaypointsNavigator::getWaypointNavStatus(TWaypointStatusSequence & out_nav_status) const
{
        // No need to lock mutex...
        out_nav_status = m_waypoint_nav_status;
}

void CWaypointsNavigator::cancel()
{
        {
                mrpt::synch::CCriticalSectionLocker csl(&m_nav_waypoints_cs);
                m_waypoint_nav_status = TWaypointStatusSequence();
        }
        CAbstractNavigator::cancel();
}

void CWaypointsNavigator::waypoints_navigationStep()
{
        MRPT_START

        using mrpt::math::square;

        // --------------------------------------
        //     Waypoint navigation algorithm
        // --------------------------------------
        m_is_aligning = false;  // the robot is aligning into a waypoint with a desired heading

        {
        mrpt::utils::CTimeLoggerEntry tle(m_timlog_delays,"CWaypointsNavigator::navigationStep()");
        mrpt::synch::CCriticalSectionLocker csl(&m_nav_waypoints_cs);

        TWaypointStatusSequence &wps = m_waypoint_nav_status; // shortcut to save typing

        if (wps.waypoints.empty() || wps.final_goal_reached)
        {
                // No nav request is pending or it was canceled
        }
        else
        {
                // 0) Get current robot pose:
                CAbstractNavigator::updateCurrentPoseAndSpeeds();

                // 1) default policy: go thru WPs one by one
                const int prev_wp_index = wps.waypoint_index_current_goal;

                mrpt::math::TSegment2D robot_move_seg;
                robot_move_seg.point1.x = m_curPoseVel.pose.x;
                robot_move_seg.point1.y = m_curPoseVel.pose.y;
                if (wps.last_robot_pose.x==TWaypoint::INVALID_NUM)
                {
                        robot_move_seg.point2 = robot_move_seg.point1;
                }
                else
                {
                        robot_move_seg.point2.x = wps.last_robot_pose.x;
                        robot_move_seg.point2.y = wps.last_robot_pose.y;
                }
                wps.last_robot_pose = m_curPoseVel.pose; // save for next iters

                decltype(m_pending_events) new_events;

                if (wps.waypoint_index_current_goal >= 0)
                {
                        auto &wp = wps.waypoints[wps.waypoint_index_current_goal];
                        const double dist2target = robot_move_seg.distance(wp.target);
                        if (dist2target < wp.allowed_distance || m_was_aligning /* we were already aligning at a WP */)
                        {
                                bool consider_wp_reached = false;
                                if (wp.target_heading == TWaypoint::INVALID_NUM)
                                {
                                        consider_wp_reached = true;
                                }
                                else
                                {
                                        // Handle pure-rotation robot interface to honor target_heading
                                        const double ang_err = mrpt::math::angDistance(m_curPoseVel.pose.phi, wp.target_heading);
                                        const double tim_since_last_align = mrpt::system::timeDifference(m_last_alignment_cmd, mrpt::system::now());
                                        const double ALIGN_WAIT_TIME = 1.5; // seconds
                                        if (std::abs(ang_err) <= params_waypoints_navigator.waypoint_angle_tolerance &&
                                            tim_since_last_align>ALIGN_WAIT_TIME // give some time for the alignment (if supported in this robot) to finish
                                            )
                                        {
                                                consider_wp_reached = true;
                                        }
                                        else
                                        {
                                                m_is_aligning = true;

                                                if (!m_was_aligning || tim_since_last_align> ALIGN_WAIT_TIME)
                                                {
                                                        // we must align:
                                                        // Send vel_cmd to the robot:
                                                        mrpt::kinematics::CVehicleVelCmdPtr align_cmd = m_robot.getAlignCmd(ang_err);

                                                        MRPT_LOG_INFO_FMT(
                                                            "[CWaypointsNavigator::navigationStep] Trying to align to heading: %.02f deg. "
                                                            "Relative heading: %.02f deg. "
                                                            "With motion cmd: %s",
                                                            mrpt::utils::RAD2DEG(wp.target_heading),
                                                            mrpt::utils::RAD2DEG(ang_err),
                                                            align_cmd ? align_cmd->asString().c_str() : "nullptr (operation not supported by this robot)");

                                                        if (align_cmd)
                                                        {
                                                                m_last_alignment_cmd = mrpt::system::now();
                                                                this->changeSpeeds(*align_cmd);
                                                        }
                                                        else
                                                        {
                                                                this->stop(false /*not emergency*/); // In any case, do a "stop"
                                                                consider_wp_reached = true; // this robot does not support "in place" alignment
                                                        }
                                                }
                                                else
                                                {
                                                        MRPT_LOG_THROTTLE_INFO_FMT(0.5, "[CWaypointsNavigator::navigationStep] Waiting for the robot to get aligned: current_heading=%.02f deg target_heading=%.02f deg", mrpt::utils::RAD2DEG(m_curPoseVel.pose.phi), mrpt::utils::RAD2DEG(wp.target_heading) );
                                                }
                                        }
                                }

                                if (consider_wp_reached)
                                {
                                        MRPT_LOG_DEBUG_STREAM("[CWaypointsNavigator::navigationStep] Waypoint " <<
                                            (wps.waypoint_index_current_goal + 1) << "/" << wps.waypoints.size() << " reached."
                                            " segment-to-target dist: " << dist2target << ", allowed_dist: " << wp.allowed_distance
                                        );

                                        wp.reached = true;
                                        wp.skipped = false;
                                        wp.timestamp_reach = mrpt::system::now();
                                        {
                                                TPendingEvent ev;
                                                ev.event_wp_reached = true;
                                                ev.event_wp_reached_index = wps.waypoint_index_current_goal;
                                                ev.event_wp_reached_reached = true /* reason: really reached*/;
                                                new_events.push_back(ev);
                                        }

                                        // Was this the final goal??
                                        if (wps.waypoint_index_current_goal < int(wps.waypoints.size() - 1)) {
                                                wps.waypoint_index_current_goal++;
                                        }
                                        else {
                                                wps.final_goal_reached = true;

                                                // Make sure the end-navigation event is issued,
                                                // navigation state switches to IDLE, etc:
                                                this->performNavigationStepNavigating(false);
                                        }
                                }
                        }
                }

                // 2) More advanced policy: if available, use children class methods to decide
                //     which is the best candidate for the next waypoint, if we can skip current one:
                if (!wps.final_goal_reached &&
                    wps.waypoint_index_current_goal >= 0 &&
                    wps.waypoints[wps.waypoint_index_current_goal].allow_skip
                    )
                {
                        const mrpt::poses::CPose2D robot_pose(m_curPoseVel.pose);
                        int most_advanced_wp = wps.waypoint_index_current_goal;
                        const int most_advanced_wp_at_begin = most_advanced_wp;

                        for (int idx=wps.waypoint_index_current_goal;idx<(int)wps.waypoints.size();idx++)
                        {
                                if (idx<0) continue;
                                if (wps.waypoints[idx].reached) continue;

                                // Is it reachable?
                                mrpt::math::TPoint2D wp_local_wrt_robot;
                                robot_pose.inverseComposePoint(wps.waypoints[idx].target, wp_local_wrt_robot);

                                if (params_waypoints_navigator.max_distance_to_allow_skip_waypoint>0 && wp_local_wrt_robot.norm()>params_waypoints_navigator.max_distance_to_allow_skip_waypoint)
                                        continue; // Skip this one, it is too far away

                                const bool is_reachable = this->impl_waypoint_is_reachable(wp_local_wrt_robot);

                                if (is_reachable) {
                                        // Robustness filter: only skip to a future waypoint if it is seen as "reachable" during
                                        // a given number of timesteps:
                                        if (++wps.waypoints[idx].counter_seen_reachable > params_waypoints_navigator.min_timesteps_confirm_skip_waypoints) {
                                                most_advanced_wp = idx;
                                        }
                                }

                                // Is allowed to skip it?
                                if (!wps.waypoints[idx].allow_skip)
                                        break; // Do not keep trying, since we are now allowed to skip this one.
                        }

                        if (most_advanced_wp>=0) {
                                wps.waypoint_index_current_goal = most_advanced_wp;
                                for (int k=most_advanced_wp_at_begin;k<most_advanced_wp;k++) {
                                        auto &wp = wps.waypoints[k];
                                        wp.reached = true;
                                        wp.skipped = true;
                                        wp.timestamp_reach = mrpt::system::now();

                                        {
                                                TPendingEvent ev;
                                                ev.event_wp_reached = true;
                                                ev.event_wp_reached_index = k;
                                                ev.event_wp_reached_reached = false /* reason: skipped */;
                                                new_events.push_back(ev);
                                        }
                                }
                        }
                }

                // Insert at the beginning, for these events to be dispatched *before* any "end of nav" event:
                m_pending_events.insert(m_pending_events.begin(), new_events.begin(), new_events.end());

                // Still not started and no better guess? Start with the first waypoint:
                if (wps.waypoint_index_current_goal<0)
                        wps.waypoint_index_current_goal = 0;

                // 3) Should I request a new (single target) navigation command?
                //    Only if the temporary goal changed:
                if (wps.waypoint_index_current_goal>=0 && prev_wp_index!=wps.waypoint_index_current_goal)
                {
                        ASSERT_( wps.waypoint_index_current_goal < int(wps.waypoints.size()) );
                        ASSERT_( params_waypoints_navigator.multitarget_look_ahead>=0);

                        // Notify we have a new "current waypoint"
                        {
                                TPendingEvent ev;
                                ev.event_new_wp = true;
                                ev.event_new_wp_index = wps.waypoint_index_current_goal;
                                // Push back so it's dispatched *after* the wp reached events:
                                m_pending_events.push_back(ev);
                        }

                        // Send the current targets + "multitarget_look_ahead" additional ones to help the local planner.
                        CWaypointsNavigator::TNavigationParamsWaypoints nav_cmd;

                        // Check skippable flag while traversing from current wp forward "multitarget_look_ahead" steps:
                        int wp_last_idx = wps.waypoint_index_current_goal;
                        for (int nstep = 0; wp_last_idx<int(wps.waypoints.size()) - 1 && nstep < params_waypoints_navigator.multitarget_look_ahead; ++nstep)
                        {
                                if (!m_waypoint_nav_status.waypoints[wp_last_idx].allow_skip)
                                        break;
                                wp_last_idx++;
                        }

                        for (int wp_idx = wps.waypoint_index_current_goal; wp_idx <= wp_last_idx; wp_idx++)
                        {
                                TWaypointStatus &wp = wps.waypoints[wp_idx];
                                const bool is_final_wp = ((wp_idx + 1) == int(wps.waypoints.size()));

                                CAbstractNavigator::TargetInfo ti;

                                ti.target_coords.x = wp.target.x;
                                ti.target_coords.y = wp.target.y;
                                ti.target_coords.phi = (wp.target_heading != TWaypoint::INVALID_NUM ? wp.target_heading : .0);
                                ti.target_frame_id = wp.target_frame_id;
                                ti.targetAllowedDistance = wp.allowed_distance;
                                ti.targetIsRelative = false;
                                ti.targetIsIntermediaryWaypoint = !is_final_wp;
                                ti.targetDesiredRelSpeed = wp.speed_ratio;

                                // For backwards compat. with single-target code, write single target info too for the first, next, waypoint:
                                if (wp_idx == wps.waypoint_index_current_goal) {
                                        nav_cmd.target = ti;
                                }
                                // Append to list of targets:
                                nav_cmd.multiple_targets.emplace_back(ti);
                        }
                        this->processNavigateCommand( &nav_cmd );

                        MRPT_LOG_DEBUG_STREAM( "[CWaypointsNavigator::navigationStep] Active waypoint changed. Current status:\n" << this->getWaypointNavStatus().getAsText());
                }
        }
        }

        // Note: navigationStep() called *after* waypoints part to get end-of-navigation events *after*
        //       waypoints-related events:

        m_was_aligning = m_is_aligning; // Let the next timestep know about this

        MRPT_END
}


void CWaypointsNavigator::navigationStep()
{
        MRPT_START
        m_is_aligning = false;  // the robot is aligning into a waypoint with a desired heading

        // State can be NAVIGATING if we are already heading to a waypoint,
        // or IDLE if navigateWaypoints() was called and this is the first
        // navStep() afterwards:
        if (m_navigationState == NAVIGATING || m_navigationState == IDLE)
        {
                waypoints_navigationStep();
        }

        // Call base navigation step to execute one-single waypoint navigation, as usual:
        if (!m_is_aligning)
        {
                CAbstractNavigator::navigationStep();  // This internally locks "m_nav_cs"
        }
        else
        {
                // otherwise, at least, process pending events:
                CAbstractNavigator::dispatchPendingNavEvents();
        }

        MRPT_END
}

void CWaypointsNavigator::onStartNewNavigation()
{
}

bool CWaypointsNavigator::isRelativePointReachable(const mrpt::math::TPoint2D &wp_local_wrt_robot) const
{
        return impl_waypoint_is_reachable(wp_local_wrt_robot);
}

void CWaypointsNavigator::loadConfigFile(const mrpt::utils::CConfigFileBase &c)
{
        MRPT_START

        params_waypoints_navigator.loadFromConfigFile(c, "CWaypointsNavigator");
        CAbstractNavigator::loadConfigFile(c);

        MRPT_END
}

void CWaypointsNavigator::saveConfigFile(mrpt::utils::CConfigFileBase &c) const
{
        CAbstractNavigator::saveConfigFile(c);
        params_waypoints_navigator.saveToConfigFile(c, "CWaypointsNavigator");
}

void mrpt::nav::CWaypointsNavigator::TWaypointsNavigatorParams::loadFromConfigFile(const mrpt::utils::CConfigFileBase & c, const std::string & s)
{
        MRPT_LOAD_CONFIG_VAR(max_distance_to_allow_skip_waypoint, double, c, s);
        MRPT_LOAD_CONFIG_VAR(min_timesteps_confirm_skip_waypoints, int, c, s);
        MRPT_LOAD_CONFIG_VAR_DEGREES(waypoint_angle_tolerance, c, s);
        MRPT_LOAD_CONFIG_VAR(multitarget_look_ahead, int, c, s);
}

void mrpt::nav::CWaypointsNavigator::TWaypointsNavigatorParams::saveToConfigFile(mrpt::utils::CConfigFileBase & c, const std::string & s) const
{
        MRPT_SAVE_CONFIG_VAR_COMMENT(max_distance_to_allow_skip_waypoint, "Max distance to `foresee` waypoints [meters]. (<0: unlimited)");
        MRPT_SAVE_CONFIG_VAR_COMMENT(min_timesteps_confirm_skip_waypoints, "Min timesteps a `future` waypoint must be seen as reachable to become the active one.");
        MRPT_SAVE_CONFIG_VAR_DEGREES_COMMENT("waypoint_angle_tolerance", waypoint_angle_tolerance, "Angular error tolerance for waypoints with an assigned heading [deg] (Default: 5 deg)");
        MRPT_SAVE_CONFIG_VAR_COMMENT(multitarget_look_ahead, ">=0 number of waypoints to forward to the underlying navigation engine, to ease obstacles avoidance when a waypoint is blocked (Default=0 : none)");
}

CWaypointsNavigator::TWaypointsNavigatorParams::TWaypointsNavigatorParams() :
    max_distance_to_allow_skip_waypoint(-1.0),
    min_timesteps_confirm_skip_waypoints(1),
    waypoint_angle_tolerance( mrpt::utils::DEG2RAD(5.0) ),
    multitarget_look_ahead(0)
{
}

bool CWaypointsNavigator::checkHasReachedTarget(const double targetDist) const
{
        bool ret;
        const TWaypointStatus *wp = nullptr;
        const auto &wps = m_waypoint_nav_status;
        if (m_navigationParams->target.targetIsIntermediaryWaypoint)
        {
                ret = false;
        }
        else if (wps.timestamp_nav_started != INVALID_TIMESTAMP)
        {
                wp = (!wps.waypoints.empty() &&
                    wps.waypoint_index_current_goal >= 0 &&
                    wps.waypoint_index_current_goal < (int)wps.waypoints.size()
                    )
                    ?
                    &wps.waypoints[wps.waypoint_index_current_goal]
                    :
                    nullptr;
                ret = (wp == nullptr && targetDist <= m_navigationParams->target.targetAllowedDistance) ||
                    (wp->reached);
        }
        else
        {
                ret = (targetDist <= m_navigationParams->target.targetAllowedDistance);
        }
        MRPT_LOG_DEBUG_STREAM("CWaypointsNavigator::checkHasReachedTarget() called "
            "with targetDist=" << targetDist << " return=" << ret << " waypoint: " <<
            (wp == nullptr ? std::string("") : wp->getAsText()) <<
            "wps.timestamp_nav_started=" <<
            (wps.timestamp_nav_started==INVALID_TIMESTAMP ?
                "INVALID_TIMESTAMP" : mrpt::system::dateTimeLocalToString(wps.timestamp_nav_started) )
            );
        return ret;
}