CParameterizedTrajectoryGenerator.cpp

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/* +------------------------------------------------------------------------+
   |                     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 "nav-precomp.h"  // Precomp header
 
#include <mrpt/serialization/CArchive.h>
#include <mrpt/nav/tpspace/CParameterizedTrajectoryGenerator.h>
#include <mrpt/system/filesystem.h>
#include <mrpt/system/os.h>
#include <mrpt/opengl/CSetOfLines.h>
 
using namespace mrpt::nav;
 
std::string CParameterizedTrajectoryGenerator::OUTPUT_DEBUG_PATH_PREFIX =
        "./reactivenav.logs";
PTG_collision_behavior_t CParameterizedTrajectoryGenerator::COLLISION_BEHAVIOR =
        mrpt::nav::COLL_BEH_BACK_AWAY;
 
IMPLEMENTS_VIRTUAL_SERIALIZABLE(
        CParameterizedTrajectoryGenerator, CSerializable, mrpt::nav)
 
CParameterizedTrajectoryGenerator::CParameterizedTrajectoryGenerator()
        : refDistance(.0),
          m_alphaValuesCount(0),
          m_score_priority(1.0),
          m_clearance_num_points(5),
          m_clearance_decimated_paths(15),
          m_nav_dyn_state(),
          m_nav_dyn_state_target_k(INVALID_PTG_PATH_INDEX),
          m_is_initialized(false)
{
}
 
void CParameterizedTrajectoryGenerator::loadDefaultParams()
{
        m_alphaValuesCount = 121;
        refDistance = 6.0;
        m_score_priority = 1.0;
        m_clearance_num_points = 5;
        m_clearance_decimated_paths = 15;
}
 
bool CParameterizedTrajectoryGenerator::supportVelCmdNOP() const
{
        return false;
}
double CParameterizedTrajectoryGenerator::maxTimeInVelCmdNOP(int path_k) const
{
        return .0;
}
 
void CParameterizedTrajectoryGenerator::loadFromConfigFile(
        const mrpt::config::CConfigFileBase& cfg, const std::string& sSection)
{
        MRPT_LOAD_HERE_CONFIG_VAR_NO_DEFAULT(
                num_paths, uint64_t, m_alphaValuesCount, cfg, sSection);
        MRPT_LOAD_CONFIG_VAR_NO_DEFAULT(refDistance, double, cfg, sSection);
        MRPT_LOAD_HERE_CONFIG_VAR(
                score_priority, double, m_score_priority, cfg, sSection);
        MRPT_LOAD_HERE_CONFIG_VAR(
                clearance_num_points, double, m_clearance_num_points, cfg, sSection);
        MRPT_LOAD_HERE_CONFIG_VAR(
                clearance_decimated_paths, double, m_clearance_decimated_paths, cfg,
                sSection);
 
        // Ensure a minimum of resolution:
        mrpt::keep_max(m_clearance_num_points, refDistance / 1.0);
 
        // Optional params, for debugging only
        MRPT_LOAD_HERE_CONFIG_VAR(
                vxi, double, m_nav_dyn_state.curVelLocal.vx, cfg, sSection);
        MRPT_LOAD_HERE_CONFIG_VAR(
                vyi, double, m_nav_dyn_state.curVelLocal.vy, cfg, sSection);
        MRPT_LOAD_HERE_CONFIG_VAR_DEGREES(
                wi, double, m_nav_dyn_state.curVelLocal.omega, cfg, sSection);
 
        MRPT_LOAD_HERE_CONFIG_VAR(
                reltrg_x, double, m_nav_dyn_state.relTarget.x, cfg, sSection);
        MRPT_LOAD_HERE_CONFIG_VAR(
                reltrg_y, double, m_nav_dyn_state.relTarget.y, cfg, sSection);
        MRPT_LOAD_HERE_CONFIG_VAR_DEGREES(
                reltrg_phi, double, m_nav_dyn_state.relTarget.phi, cfg, sSection);
 
        MRPT_LOAD_HERE_CONFIG_VAR(
                target_rel_speed, double, m_nav_dyn_state.targetRelSpeed, cfg,
                sSection);
}
void CParameterizedTrajectoryGenerator::saveToConfigFile(
        mrpt::config::CConfigFileBase& cfg, const std::string& sSection) const
{
        MRPT_START
        const int WN = 25, WV = 30;
 
        cfg.write(
                sSection, "num_paths", m_alphaValuesCount, WN, WV,
                "Number of discrete paths (`resolution`) in the PTG");
        cfg.write(
                sSection, "refDistance", refDistance, WN, WV,
                "Maximum distance (meters) for building trajectories (visibility "
                "range)");
        cfg.write(
                sSection, "score_priority", m_score_priority, WN, WV,
                "When used in path planning, a multiplying factor (default=1.0) for "
                "the scores for this PTG. Assign values <1 to PTGs with low priority.");
        cfg.write(
                sSection, "clearance_num_points", m_clearance_num_points, WN, WV,
                "Number of steps for the piecewise-constant approximation of clearance "
                "(Default=5).");
        cfg.write(
                sSection, "clearance_decimated_paths", m_clearance_decimated_paths, WN,
                WV,
                "Number of decimated paths for estimation of clearance (Default=15).");
 
        // Optional params, for debugging only
        cfg.write(
                sSection, "vxi", m_nav_dyn_state.curVelLocal.vx, WN, WV,
                "(Only for debugging) Current robot velocity vx [m/s].");
        cfg.write(
                sSection, "vyi", m_nav_dyn_state.curVelLocal.vy, WN, WV,
                "(Only for debugging) Current robot velocity vy [m/s].");
        cfg.write(
                sSection, "wi", mrpt::RAD2DEG(m_nav_dyn_state.curVelLocal.omega), WN,
                WV, "(Only for debugging) Current robot velocity omega [deg/s].");
 
        cfg.write(
                sSection, "reltrg_x", m_nav_dyn_state.relTarget.x, WN, WV,
                "(Only for debugging) Relative target x [m].");
        cfg.write(
                sSection, "reltrg_y", m_nav_dyn_state.relTarget.y, WN, WV,
                "(Only for debugging) Relative target y [m].");
        cfg.write(
                sSection, "reltrg_phi", mrpt::RAD2DEG(m_nav_dyn_state.relTarget.phi),
                WN, WV, "(Only for debugging) Relative target phi [deg].");
 
        cfg.write(
                sSection, "target_rel_speed", m_nav_dyn_state.targetRelSpeed, WN, WV,
                "(Only for debugging) Desired relative speed at target [0,1]");
 
        MRPT_END
}
 
void CParameterizedTrajectoryGenerator::internal_readFromStream(
        mrpt::serialization::CArchive& in)
{
        this->deinitialize();
 
        uint8_t version;
        in >> version;
        switch (version)
        {
                case 0:
                case 1:
                case 2:
                case 3:
                case 4:
                        in >> refDistance >> m_alphaValuesCount >> m_score_priority;
                        if (version >= 1) in >> m_clearance_num_points;
                        if (version == 2)
                        {
                                bool old_use_approx_clearance;
                                in >> old_use_approx_clearance;  // ignored in v>=3
                        }
                        if (version >= 4)
                        {
                                in >> m_clearance_decimated_paths;
                        }
                        else
                        {
                                m_clearance_decimated_paths = m_alphaValuesCount;
                        }
                        break;
                default:
                        MRPT_THROW_UNKNOWN_SERIALIZATION_VERSION(version)
        };
}
 
void CParameterizedTrajectoryGenerator::internal_writeToStream(
        mrpt::serialization::CArchive& out) const
{
        const uint8_t version = 4;
        out << version;
 
        out << refDistance << m_alphaValuesCount << m_score_priority
                << m_clearance_num_points /* v1 */;
        out << m_clearance_decimated_paths /* v4*/;
}
 
double CParameterizedTrajectoryGenerator::index2alpha(
        uint16_t k, const unsigned int num_paths)
{
        ASSERT_BELOW_(k, num_paths);
        return M_PI * (-1.0 + 2.0 * (k + 0.5) / num_paths);
}
 
double CParameterizedTrajectoryGenerator::index2alpha(uint16_t k) const
{
        return index2alpha(k, m_alphaValuesCount);
}
 
uint16_t CParameterizedTrajectoryGenerator::alpha2index(
        double alpha, const unsigned int num_paths)
{
        mrpt::math::wrapToPi(alpha);
        int k = mrpt::round(0.5 * (num_paths * (1.0 + alpha / M_PI) - 1.0));
        if (k < 0) k = 0;
        if (k >= static_cast<int>(num_paths)) k = num_paths - 1;
        return (uint16_t)k;
}
 
uint16_t CParameterizedTrajectoryGenerator::alpha2index(double alpha) const
{
        return alpha2index(alpha, m_alphaValuesCount);
}
 
void CParameterizedTrajectoryGenerator::renderPathAsSimpleLine(
        const uint16_t k, mrpt::opengl::CSetOfLines& gl_obj,
        const double decimate_distance, const double max_path_distance) const
{
        const size_t nPointsInPath = getPathStepCount(k);
 
        bool first = true;
        // Decimate trajectories: we don't need centimeter resolution!
        double last_added_dist = 0.0;
        for (size_t n = 0; n < nPointsInPath; n++)
        {
                const double d = this->getPathDist(
                        k, n);  // distance thru path "k" until timestep "n"
 
                // Draw the TP only until we reach the target of the "motion" segment:
                if (max_path_distance >= 0.0 && d >= max_path_distance) break;
 
                if (d < last_added_dist + decimate_distance && n != 0)
                        continue;  // skip: decimation
 
                last_added_dist = d;
 
                mrpt::math::TPose2D p;
                this->getPathPose(k, n, p);
 
                if (first)
                {
                        first = false;
                        gl_obj.appendLine(0, 0, 0, p.x, p.y, 0);
                }
                else
                        gl_obj.appendLineStrip(p.x, p.y, 0);
        }
}
 
void CParameterizedTrajectoryGenerator::initTPObstacles(
        std::vector<double>& TP_Obstacles) const
{
        TP_Obstacles.resize(m_alphaValuesCount);
        for (size_t k = 0; k < m_alphaValuesCount; k++)
                initTPObstacleSingle(k, TP_Obstacles[k]);
}
void CParameterizedTrajectoryGenerator::initTPObstacleSingle(
        uint16_t k, double& TP_Obstacle_k) const
{
        TP_Obstacle_k = std::min(
                refDistance, m_nav_dyn_state_target_k != INVALID_PTG_PATH_INDEX
                                                 ? refDistance
                                                 : this->getPathDist(k, this->getPathStepCount(k) - 1));
}
 
bool CParameterizedTrajectoryGenerator::debugDumpInFiles(
        const std::string& ptg_name) const
{
        using namespace mrpt::system;
        using namespace std;
 
        const char* sPath =
                CParameterizedTrajectoryGenerator::OUTPUT_DEBUG_PATH_PREFIX.c_str();
 
        mrpt::system::createDirectory(sPath);
        mrpt::system::createDirectory(mrpt::format("%s/PTGs", sPath));
 
        const string sFilTxt_x =
                mrpt::format("%s/PTGs/PTG%s_x.txt", sPath, ptg_name.c_str());
        const string sFilTxt_y =
                mrpt::format("%s/PTGs/PTG%s_y.txt", sPath, ptg_name.c_str());
        const string sFilTxt_phi =
                mrpt::format("%s/PTGs/PTG%s_phi.txt", sPath, ptg_name.c_str());
        const string sFilTxt_t =
                mrpt::format("%s/PTGs/PTG%s_t.txt", sPath, ptg_name.c_str());
        const string sFilTxt_d =
                mrpt::format("%s/PTGs/PTG%s_d.txt", sPath, ptg_name.c_str());
 
        ofstream fx(sFilTxt_x.c_str());
        if (!fx.is_open()) return false;
        ofstream fy(sFilTxt_y.c_str());
        if (!fy.is_open()) return false;
        ofstream fp(sFilTxt_phi.c_str());
        if (!fp.is_open()) return false;
        ofstream fd(sFilTxt_d.c_str());
        if (!fd.is_open()) return false;
 
        const size_t nPaths = getAlphaValuesCount();
 
        // Text version:
        fx << "% PTG data file for 'x'. Each row is the trajectory for a different "
                  "'alpha' parameter value."
           << endl;
        fy << "% PTG data file for 'y'. Each row is the trajectory for a different "
                  "'alpha' parameter value."
           << endl;
        fp << "% PTG data file for 'phi'. Each row is the trajectory for a "
                  "different 'alpha' parameter value."
           << endl;
        fd << "% PTG data file for 'd'. Each row is the trajectory for a different "
                  "'alpha' parameter value."
           << endl;
 
        vector<size_t> path_length(nPaths);
        for (size_t k = 0; k < nPaths; k++) path_length[k] = getPathStepCount(k);
 
        size_t maxPoints = 0;
        for (size_t k = 0; k < nPaths; k++)
                maxPoints = max(maxPoints, path_length[k]);
 
        for (size_t k = 0; k < nPaths; k++)
        {
                for (size_t n = 0; n < maxPoints; n++)
                {
                        const size_t nn = std::min(n, path_length[k] - 1);
                        mrpt::math::TPose2D p;
                        this->getPathPose(k, nn, p);
                        fx << p.x << " ";
                        fy << p.y << " ";
                        fp << p.phi << " ";
                        fd << this->getPathDist(k, nn) << " ";
                }
                fx << endl;
                fy << endl;
                fp << endl;
                fd << endl;
        }
 
        return true;
}
 
bool CParameterizedTrajectoryGenerator::isInitialized() const
{
        return m_is_initialized;
}
 
void CParameterizedTrajectoryGenerator::updateNavDynamicState(
        const CParameterizedTrajectoryGenerator::TNavDynamicState& newState,
        const bool force_update)
{
        // Make sure there is a real difference: notifying a PTG that a condition
        // changed
        // may imply a significant computational cost if paths need to be
        // re-evaluated on the fly, etc.
        // so the cost of the comparison here is totally worth:
        if (force_update || m_nav_dyn_state != newState)
        {
                ASSERT_(
                        newState.targetRelSpeed >= .0 &&
                        newState.targetRelSpeed <= 1.0);  // sanity check
                m_nav_dyn_state = newState;
 
                // 1st) Build PTG paths without counting for target slow-down:
                m_nav_dyn_state_target_k = INVALID_PTG_PATH_INDEX;
 
                this->onNewNavDynamicState();
 
                // 2nd) Save the special path for slow-down:
                if (this->supportSpeedAtTarget())
                {
                        int target_k = -1;
                        double target_norm_d;
                        // bool is_exact = // JLB removed this constraint for being too
                        // restrictive.
                        this->inverseMap_WS2TP(
                                m_nav_dyn_state.relTarget.x, m_nav_dyn_state.relTarget.y,
                                target_k, target_norm_d, 1.0 /*large tolerance*/);
                        if (target_norm_d > 0.01 && target_norm_d < 0.99 && target_k >= 0 &&
                                target_k < m_alphaValuesCount)
                        {
                                m_nav_dyn_state_target_k = target_k;
                                this->onNewNavDynamicState();  // Recalc
                        }
                }
        }
}
 
void CParameterizedTrajectoryGenerator::initialize(
        const std::string& cacheFilename, const bool verbose)
{
        if (m_is_initialized) return;
 
        const std::string sCache =
                !cacheFilename.empty()
                        ? cacheFilename
                        : std::string("cache_") +
                                  mrpt::system::fileNameStripInvalidChars(getDescription()) +
                                  std::string(".bin.gz");
 
        this->internal_initialize(sCache, verbose);
        m_is_initialized = true;
}
void CParameterizedTrajectoryGenerator::deinitialize()
{
        if (!m_is_initialized) return;
        this->internal_deinitialize();
        m_is_initialized = false;
}
 
void CParameterizedTrajectoryGenerator::internal_TPObsDistancePostprocess(
        const double ox, const double oy, const double new_tp_obs_dist,
        double& inout_tp_obs) const
{
        const bool is_obs_inside_robot_shape = isPointInsideRobotShape(ox, oy);
        if (!is_obs_inside_robot_shape)
        {
                mrpt::keep_min(inout_tp_obs, new_tp_obs_dist);
                return;
        }
 
        // Handle the special case of obstacles *inside* the robot at the begining
        // of the PTG path:
        switch (COLLISION_BEHAVIOR)
        {
                case COLL_BEH_STOP:
                        inout_tp_obs = .0;
                        break;
 
                case COLL_BEH_BACK_AWAY:
                {
                        if (new_tp_obs_dist < getMaxRobotRadius())
                        {
                                // This means that we are getting apart of the obstacle:
                                // ignore it to allow the robot to get off the near-collision:
                                // Don't change inout_tp_obs.
                                return;
                        }
                        else
                        {
                                // This means we are already in collision and trying to get even
                                // closer
                                // to the obstacle: totally disprove this action:
                                inout_tp_obs = .0;
                        }
                }
                break;
 
                default:
                        THROW_EXCEPTION("Obstacle postprocessing enum not implemented!");
        }
}
 
void mrpt::nav::CParameterizedTrajectoryGenerator::initClearanceDiagram(
        ClearanceDiagram& cd) const
{
        cd.resize(m_alphaValuesCount, m_clearance_decimated_paths);
        for (unsigned int decim_k = 0; decim_k < m_clearance_decimated_paths;
                 decim_k++)
        {
                const auto real_k = cd.decimated_k_to_real_k(decim_k);
                const size_t numPathSteps = getPathStepCount(real_k);
                const double numStepsPerIncr =
                        (numPathSteps - 1.0) / double(m_clearance_num_points);
 
                auto& cl_path = cd.get_path_clearance_decimated(decim_k);
                for (double step_pointer_dbl = 0.0; step_pointer_dbl < numPathSteps;
                         step_pointer_dbl += numStepsPerIncr)
                {
                        const size_t step = mrpt::round(step_pointer_dbl);
                        const double dist_over_path = this->getPathDist(real_k, step);
                        cl_path[dist_over_path] = 1.0;  // create entry in map<>
                }
        }
}
 
void CParameterizedTrajectoryGenerator::updateClearance(
        const double ox, const double oy, ClearanceDiagram& cd) const
{
        // Initialize CD on first call:
        ASSERT_(cd.get_actual_num_paths() == m_alphaValuesCount);
        ASSERT_(m_clearance_num_points > 0 && m_clearance_num_points < 10000);
 
        // evaluate in derived-class: this function also keeps the minimum
        // automatically.
        for (uint16_t decim_k = 0; decim_k < cd.get_decimated_num_paths();
                 decim_k++)
        {
                const auto real_k = cd.decimated_k_to_real_k(decim_k);
                this->evalClearanceSingleObstacle(
                        ox, oy, real_k, cd.get_path_clearance_decimated(decim_k));
        }
}
 
void CParameterizedTrajectoryGenerator::updateClearancePost(
        ClearanceDiagram& cd, const std::vector<double>& TP_obstacles) const
{
        // Used only when in approx mode (Removed 30/01/2017)
}
 
void CParameterizedTrajectoryGenerator::evalClearanceSingleObstacle(
        const double ox, const double oy, const uint16_t k,
        ClearanceDiagram::dist2clearance_t& inout_realdist2clearance,
        bool treat_as_obstacle) const
{
        bool had_collision = false;
 
        const size_t numPathSteps = getPathStepCount(k);
        ASSERT_(numPathSteps > inout_realdist2clearance.size());
 
        const double numStepsPerIncr =
                (numPathSteps - 1.0) / (inout_realdist2clearance.size());
 
        double step_pointer_dbl = 0.0;
        const mrpt::math::TPoint2D og(ox, oy);  // obstacle in "global" frame
        mrpt::math::TPoint2D ol;  // obstacle in robot frame
 
        for (auto& e : inout_realdist2clearance)
        {
                step_pointer_dbl += numStepsPerIncr;
                const size_t step = mrpt::round(step_pointer_dbl);
                // const double dist_over_path = e.first;
                double& inout_clearance = e.second;
 
                if (had_collision)
                {
                        // We found a collision in a previous step along this "k" path, so
                        // it does not make sense to evaluate the clearance of a pose which
                        // is not reachable:
                        inout_clearance = .0;
                        continue;
                }
 
                mrpt::math::TPose2D pose;
                this->getPathPose(k, step, pose);
 
                // obstacle to robot clearance:
                ol = pose.inverseComposePoint(og);
                const double this_clearance =
                        treat_as_obstacle ? this->evalClearanceToRobotShape(ol.x, ol.y)
                                                          : ol.norm();
                if (this_clearance <= .0 && treat_as_obstacle)
                {
                        // Collision:
                        had_collision = true;
                        inout_clearance = .0;
                }
                else
                {
                        // The obstacle is not a direct collision.
                        const double this_clearance_norm =
                                this_clearance / this->refDistance;
 
                        // Update minimum in output structure
                        mrpt::keep_min(inout_clearance, this_clearance_norm);
                }
        }
}
 
CParameterizedTrajectoryGenerator::TNavDynamicState::TNavDynamicState()
        : curVelLocal(0, 0, 0),
          relTarget(20.0, 0, 0),  // Default: assume a "distant" target ahead
          targetRelSpeed(0)
{
}
 
bool CParameterizedTrajectoryGenerator::TNavDynamicState::operator==(
        const TNavDynamicState& o) const
{
        return (curVelLocal == o.curVelLocal) && (relTarget == o.relTarget) &&
                   (targetRelSpeed == o.targetRelSpeed);
}
 
void mrpt::nav::CParameterizedTrajectoryGenerator::TNavDynamicState::
	writeToStream(mrpt::serialization::CArchive& out) const
{
        const uint8_t version = 0;
        out << version;
        // Data:
        out << curVelLocal << relTarget << targetRelSpeed;
}
 
void mrpt::nav::CParameterizedTrajectoryGenerator::TNavDynamicState::
	readFromStream(mrpt::serialization::CArchive& in)
{
        uint8_t version;
        in >> version;
        switch (version)
        {
                case 0:
                        in >> curVelLocal >> relTarget >> targetRelSpeed;
                        break;
                default:
                        MRPT_THROW_UNKNOWN_SERIALIZATION_VERSION(version);
        };
}