ardupilot/libraries/APO/AP_Guide.cpp

/*
 * AP_Guide.cpp
 *
 *  Created on: Apr 30, 2011
 *      Author: jgoppert
 */

#include "AP_Guide.h"
#include "../FastSerial/FastSerial.h"
#include "AP_Navigator.h"
#include "constants.h"
#include "AP_HardwareAbstractionLayer.h"
#include "AP_CommLink.h"

namespace apo {

AP_Guide::AP_Guide(AP_Navigator * navigator, AP_HardwareAbstractionLayer * hal) :
    _navigator(navigator), _hal(hal), _command(AP_MavlinkCommand::home),
    _previousCommand(AP_MavlinkCommand::home),
    _headingCommand(0), _airSpeedCommand(0),
    _groundSpeedCommand(0), _altitudeCommand(0), _pNCmd(0),
    _pECmd(0), _pDCmd(0), _mode(MAV_NAV_LOST),
    _numberOfCommands(1), _cmdIndex(0), _nextCommandCalls(0),
    _nextCommandTimer(0) {
}

void AP_Guide::setCurrentIndex(uint8_t val) {
    _cmdIndex.set_and_save(val);
    _command = AP_MavlinkCommand(getCurrentIndex());
    _previousCommand = AP_MavlinkCommand(getPreviousIndex());
    _hal->gcs->sendMessage(MAVLINK_MSG_ID_WAYPOINT_CURRENT);
}

float AP_Guide::getHeadingError() {
    float headingError = getHeadingCommand()
                         - _navigator->getYaw();
    if (headingError > 180 * deg2Rad)
        headingError -= 360 * deg2Rad;
    if (headingError < -180 * deg2Rad)
        headingError += 360 * deg2Rad;
    return headingError;
}

MavlinkGuide::MavlinkGuide(AP_Navigator * navigator,
                           AP_HardwareAbstractionLayer * hal, float velCmd, float xt, float xtLim) :
    AP_Guide(navigator, hal), _rangeFinderFront(), _rangeFinderBack(),
    _rangeFinderLeft(), _rangeFinderRight(),
    _group(k_guide, PSTR("guide_")),
    _velocityCommand(&_group, 1, velCmd, PSTR("velCmd")),
    _crossTrackGain(&_group, 2, xt, PSTR("xt")),
    _crossTrackLim(&_group, 3, xtLim, PSTR("xtLim")) {

    for (uint8_t i = 0; i < _hal->rangeFinders.getSize(); i++) {
        RangeFinder * rF = _hal->rangeFinders[i];
        if (rF == NULL)
            continue;
        if (rF->orientation_x == 1 && rF->orientation_y == 0
                && rF->orientation_z == 0)
            _rangeFinderFront = rF;
        else if (rF->orientation_x == -1 && rF->orientation_y == 0
                 && rF->orientation_z == 0)
            _rangeFinderBack = rF;
        else if (rF->orientation_x == 0 && rF->orientation_y == 1
                 && rF->orientation_z == 0)
            _rangeFinderRight = rF;
        else if (rF->orientation_x == 0 && rF->orientation_y == -1
                 && rF->orientation_z == 0)
            _rangeFinderLeft = rF;

    }
}

void MavlinkGuide::update() {
    // process mavlink commands
    handleCommand();

    // obstacle avoidance overrides
    // stop if your going to drive into something in front of you
    for (uint8_t i = 0; i < _hal->rangeFinders.getSize(); i++)
        _hal->rangeFinders[i]->read();
    float frontDistance = _rangeFinderFront->distance / 200.0; //convert for other adc
    if (_rangeFinderFront && frontDistance < 2) {
        _mode = MAV_NAV_VECTOR;

        //airSpeedCommand = 0;
        //groundSpeedCommand = 0;
//			_headingCommand -= 45 * deg2Rad;
//			_hal->debug->print("Obstacle Distance (m): ");
//			_hal->debug->println(frontDistance);
//			_hal->debug->print("Obstacle avoidance Heading Command: ");
//			_hal->debug->println(headingCommand);
//			_hal->debug->printf_P(
//					PSTR("Front Distance, %f\n"),
//					frontDistance);
    }
    if (_rangeFinderBack && _rangeFinderBack->distance < 5) {
        _airSpeedCommand = 0;
        _groundSpeedCommand = 0;

    }

    if (_rangeFinderLeft && _rangeFinderLeft->distance < 5) {
        _airSpeedCommand = 0;
        _groundSpeedCommand = 0;
    }

    if (_rangeFinderRight && _rangeFinderRight->distance < 5) {
        _airSpeedCommand = 0;
        _groundSpeedCommand = 0;
    }
}

void MavlinkGuide::nextCommand() {
    // within 1 seconds, check if more than 5 calls to next command occur
    // if they do, go to home waypoint
    if (millis() - _nextCommandTimer < 1000) {
        if (_nextCommandCalls > 5) {
            Serial.println("commands loading too fast, returning home");
            setCurrentIndex(0);
            setNumberOfCommands(1);
            _nextCommandCalls = 0;
            _nextCommandTimer = millis();
            return;
        }
        _nextCommandCalls++;
    } else {
        _nextCommandTimer = millis();
        _nextCommandCalls = 0;
    }

    setCurrentIndex(getNextIndex());
    //Serial.print("cmd       : "); Serial.println(int(_cmdIndex));
    //Serial.print("cmd prev  : "); Serial.println(int(getPreviousIndex()));
    //Serial.print("cmd num    : "); Serial.println(int(getNumberOfCommands()));
    _command = AP_MavlinkCommand(getCurrentIndex());
    _previousCommand = AP_MavlinkCommand(getPreviousIndex());
}

void MavlinkGuide::handleCommand() {

    // TODO handle more commands
    switch (_command.getCommand()) {

    case MAV_CMD_NAV_WAYPOINT: {

        // if we don't have enough waypoint for cross track calcs
        // go home
        if (_numberOfCommands == 1) {
            _mode = MAV_NAV_RETURNING;
            _altitudeCommand = AP_MavlinkCommand::home.getAlt();
            _headingCommand = AP_MavlinkCommand::home.bearingTo(
                                  _navigator->getLat_degInt(), _navigator->getLon_degInt())
                              + 180 * deg2Rad;
            if (_headingCommand > 360 * deg2Rad)
                _headingCommand -= 360 * deg2Rad;

            //_hal->debug->printf_P(PSTR("going home: bearing: %f distance: %f\n"),
            //headingCommand,AP_MavlinkCommand::home.distanceTo(_navigator->getLat_degInt(),_navigator->getLon_degInt()));

            // if we have 2 or more waypoints do x track navigation
        } else {
            _mode = MAV_NAV_WAYPOINT;
            float alongTrack = _command.alongTrack(_previousCommand,
                                                   _navigator->getLat_degInt(),
                                                   _navigator->getLon_degInt());
            float distanceToNext = _command.distanceTo(
                                       _navigator->getLat_degInt(), _navigator->getLon_degInt());
            float segmentLength = _previousCommand.distanceTo(_command);
            if (distanceToNext < _command.getRadius() || alongTrack
                    > segmentLength)
            {
                Serial.println("waypoint reached");
                nextCommand();
            }
            _altitudeCommand = _command.getAlt();
            float dXt = _command.crossTrack(_previousCommand,
                                            _navigator->getLat_degInt(),
                                            _navigator->getLon_degInt());
            float temp = dXt * _crossTrackGain * deg2Rad; // crosstrack gain, rad/m
            if (temp > _crossTrackLim * deg2Rad)
                temp = _crossTrackLim * deg2Rad;
            if (temp < -_crossTrackLim * deg2Rad)
                temp = -_crossTrackLim * deg2Rad;
            float bearing = _previousCommand.bearingTo(_command);
            _headingCommand = bearing - temp;
            //_hal->debug->printf_P(
            //PSTR("nav: bCurrent2Dest: %f\tdXt: %f\tcmdHeading: %f\tnextWpDistance: %f\talongTrack: %f\n"),
            //bearing * rad2Deg, dXt, _headingCommand * rad2Deg, distanceToNext, alongTrack);
        }

        _groundSpeedCommand = _velocityCommand;

        // calculate pN,pE,pD from home and gps coordinates
        _pNCmd = _command.getPN(_navigator->getLat_degInt(),
                                _navigator->getLon_degInt());
        _pECmd = _command.getPE(_navigator->getLat_degInt(),
                                _navigator->getLon_degInt());
        _pDCmd = _command.getPD(_navigator->getAlt_intM());

        // debug
        //_hal->debug->printf_P(
        //PSTR("guide loop, number: %d, current index: %d, previous index: %d\n"),
        //getNumberOfCommands(),
        //getCurrentIndex(),
        //getPreviousIndex());

        break;
    }
//		case MAV_CMD_CONDITION_CHANGE_ALT:
//		case MAV_CMD_CONDITION_DELAY:
//		case MAV_CMD_CONDITION_DISTANCE:
//		case MAV_CMD_CONDITION_LAST:
//		case MAV_CMD_CONDITION_YAW:
//		case MAV_CMD_DO_CHANGE_SPEED:
//		case MAV_CMD_DO_CONTROL_VIDEO:
//		case MAV_CMD_DO_JUMP:
//	    case MAV_CMD_DO_LAST:
//		case MAV_CMD_DO_LAST:
//		case MAV_CMD_DO_REPEAT_RELAY:
//		case MAV_CMD_DO_REPEAT_SERVO:
//		case MAV_CMD_DO_SET_HOME:
//		case MAV_CMD_DO_SET_MODE:
//		case MAV_CMD_DO_SET_PARAMETER:
//		case MAV_CMD_DO_SET_RELAY:
//		case MAV_CMD_DO_SET_SERVO:
//		case MAV_CMD_PREFLIGHT_CALIBRATION:
//		case MAV_CMD_PREFLIGHT_STORAGE:
//		case MAV_CMD_NAV_LAND:
//		case MAV_CMD_NAV_LAST:
//		case MAV_CMD_NAV_LOITER_TIME:
//		case MAV_CMD_NAV_LOITER_TURNS:
//		case MAV_CMD_NAV_LOITER_UNLIM:
//		case MAV_CMD_NAV_ORIENTATION_TARGET:
//		case MAV_CMD_NAV_PATHPLANNING:
//		case MAV_CMD_NAV_RETURN_TO_LAUNCH:
//		case MAV_CMD_NAV_TAKEOFF:
    default:
        // unhandled command, skip
        Serial.println("unhandled command");
        nextCommand();
        break;
    }
}

} // namespace apo

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