ardupilot/libraries/APO/AP_Guide.h

/*
 * AP_Guide.h
 * Copyright (C) James Goppert 2010 <james.goppert@gmail.com>
 *
 * This file is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This file 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/>.
 */

#ifndef AP_Guide_H
#define AP_Guide_H

#include "../GCS_MAVLink/GCS_MAVLink.h"
#include "AP_HardwareAbstractionLayer.h"
#include "AP_Navigator.h"
#include "../AP_Common/AP_Common.h"
#include "../AP_Common/AP_Vector.h"
#include "AP_MavlinkCommand.h"
#include "constants.h"

//#include "AP_CommLink.h"

namespace apo {


/// Guide class
class AP_Guide {
public:

	/**
	 * This is the constructor, which requires a link to the navigator.
	 * @param navigator This is the navigator pointer.
	 */
	AP_Guide(AP_Navigator * navigator, AP_HardwareAbstractionLayer * hal) :
		_navigator(navigator), headingCommand(0), airSpeedCommand(0),
				groundSpeedCommand(0), altitudeCommand(0), pNCmd(0), pECmd(0),
				pDCmd(0), _hal(hal), _home(0), _command(0), _previousCommand(0),
				_mode(MAV_NAV_LOST), _numberOfCommands(1), _cmdIndex(0)
	{
	}

	virtual void update() = 0;
	virtual void nextCommand() = 0;
	float headingCommand;
	float airSpeedCommand;
	float groundSpeedCommand;
	float altitudeCommand;
	float pNCmd;
	float pECmd;
	float pDCmd;
	MAV_NAV getMode() const
	{
	   	return _mode;
	}
	uint8_t getCurrentIndex()
	{
		return _cmdIndex;
	}

	void 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);
	}

	uint8_t getNumberOfCommands()
	{
		return _numberOfCommands;
	}

	void setNumberOfCommands(uint8_t val)
	{
		_numberOfCommands.set_and_save(val);
	}

	uint8_t getPreviousIndex() {
			// find previous waypoint, TODO, handle non-nav commands
			int16_t prevIndex = int16_t(getCurrentIndex()) -1 ;
			if (prevIndex < 0) prevIndex = getNumberOfCommands()-1;
			return (uint8_t)prevIndex;
		}

	uint8_t getNextIndex() {
		// find previous waypoint, TODO, handle non-nav commands
		int16_t nextIndex = int16_t(getCurrentIndex()) + 1 ;
		if (nextIndex > (getNumberOfCommands() -1)) nextIndex = 0;
		return nextIndex;
	}

protected:

	AP_MavlinkCommand _home, _command, _previousCommand;
	MAV_NAV _mode;
	AP_Uint8 _numberOfCommands;
	AP_Uint8 _cmdIndex;
	AP_Navigator * _navigator;
	AP_HardwareAbstractionLayer * _hal;
};

class MavlinkGuide: public AP_Guide {
public:
	MavlinkGuide(AP_Var::Key key, AP_Navigator * navigator, AP_HardwareAbstractionLayer * hal) :
		AP_Guide(navigator, hal), _rangeFinderFront(), _rangeFinderBack(),
				_rangeFinderLeft(), _rangeFinderRight(),
				_group(key,PSTR("GUIDE_")),
				_velocityCommand(&_group, 1, 1, PSTR("VELCMD")),
				_crossTrackGain(&_group, 2, 2, PSTR("XTK")),
				_crossTrackLim(&_group, 3, 10, PSTR("XTLIM"))
		{

		for (int 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;

		}
	}

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



		// if we don't have enough waypoint for cross track calcs
		// go home
		if (_numberOfCommands == 1) {
			headingCommand = _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,home.distanceTo(_navigator->getLat_degInt(),_navigator->getLon_degInt()));
					*/
		} else {
			// TODO wrong behavior if 0 selected as waypoint, says previous 0
			float dXt = AP_MavlinkCommand::crossTrack(_previousCommand,
					_command, _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;
			float alongTrack = AP_MavlinkCommand::alongTrack(_previousCommand,_command,
					_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) nextCommand();
			/*
			_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;

		// TODO : calculate pN,pE,pD from home and gps coordinates
		pNCmd = 0;
		pECmd = 0;
		pDCmd = 0;

		// process mavlink commands
		//handleCommand();

		// obstacle avoidance overrides
		// stop if your going to drive into something in front of you
		for(int 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) {
			//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 nextCommand() {
		_cmdIndex = getNextIndex();
		_command = AP_MavlinkCommand(getCurrentIndex());
		_previousCommand = AP_MavlinkCommand(getPreviousIndex());
		//_hal->gcs->sendMessage(MAVLINK_MSG_ID_WAYPOINT_CURRENT);
	}

	void handleCommand(AP_MavlinkCommand command,
			AP_MavlinkCommand previousCommand) {
		// TODO handle more commands
		switch (command.getCommand()) {
		case MAV_CMD_NAV_WAYPOINT: {
			// if within radius, increment
			float d = previousCommand.distanceTo(_navigator->getLat_degInt(),
					_navigator->getLon_degInt());
			if (d < command.getRadius()) {
				nextCommand();
			}
			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
			nextCommand();
			break;
		}
	}
private:
	RangeFinder * _rangeFinderFront;
	RangeFinder * _rangeFinderBack;
	RangeFinder * _rangeFinderLeft;
	RangeFinder * _rangeFinderRight;
	AP_Var_group _group;
	AP_Float _velocityCommand;
	AP_Float _crossTrackGain;
	AP_Float _crossTrackLim;
};

} // namespace apo

#endif // AP_Guide_H
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