/*
* Copyright (c) 2005-2010 KOM – Multimedia Communications Lab
*
* This file is part of PeerfactSim.KOM.
*
* PeerfactSim.KOM 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
* any later version.
*
* PeerfactSim.KOM 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 PeerfactSim.KOM. If not, see .
*
*/
package de.tud.kom.p2psim.impl.topology.movement.aerial;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.Map;
import javax.persistence.criteria.CriteriaBuilder.In;
import org.apache.commons.math3.geometry.euclidean.twod.Vector2D;
import org.joda.time.tz.ZoneInfoProvider;
import de.tud.kom.p2psim.api.topology.movement.UAVMovementModel;
import de.tud.kom.p2psim.impl.energy.components.StatelessMotorComponent;
import de.tud.kom.p2psim.impl.topology.component.UAVTopologyComponent;
import de.tud.kom.p2psim.impl.topology.util.PositionVector;
import de.tudarmstadt.maki.simonstrator.api.Time;
import de.tudarmstadt.maki.simonstrator.api.uavsupport.callbacks.ReachedLocationCallback;
/**
* Local movement logic specifically designs the movement for multicopter UAVs.
* This simple movement logic uses straight forward movement with the maximum speed available.
*
* @author Julian Zobel
* @version 1.0, 11.09.2018
*/
public class SimpleMulticopterMovement implements UAVMovementModel {
private UAVTopologyComponent topologyComponent;
private double currentAngleOfAttack;
private double currentSpeed;
private double targetedSpeed;
private LinkedList route = new LinkedList<>();
private Map locationCallbacks = new LinkedHashMap<>(); // TODO callback interface
private StatelessMotorComponent motor;
private double mass = 1.465; // kg
private final double airdensity = 1.2255; // kg/m^3
private final double gravity = 9.807; // m/s^2
private double A_top = 0.245; // m^2
private double A_front = 0.04; // m^2
private double dragCoefficient = 0.5;
private double maxPitchAngle = Math.toRadians(45); // 45° max angle
private double descentVelocityMax = 5; // m/s
private double maxTurnAngle = Math.toRadians(90); // 90° per second turn angle
// FIXME remove only for testing
private static boolean first = true;
public SimpleMulticopterMovement(UAVTopologyComponent topologyComponent) {
this.topologyComponent = topologyComponent;
}
@Override
public void move(long timeBetweenMovementOperations) {
if(first) {
System.out.println("***MOVEMENT MODEL****");
System.out.println("Hover thrust: " + hoverThrustRequired() + "N");
System.out.println("Maximum thrust: " + motor.getMaxThrust() + "N");
System.out.println("Vertical ascension: " + verticalAscentMaxAcceleration() + " m/s^2 >> max velocity" + verticalAscentMaxVelocity() + " m/s at maximum thrust");
System.out.println("Horizontal Flight: " + horizontalMaxVelocityRequiredTotalThrust() + " N >> max velocity" + horizontalMaxVelocity() + " m/s @ 45° pitch angle, minimum velocity " + this.minimumHorizontalVelocity() + " m/s @ 0.25° pitch angle");
System.out.println("************");
for (int i = (int) Math.ceil(minimumHorizontalVelocity()); i <= horizontalMaxVelocity(); i++) {
double est = estimatePowerConsumption(i);
System.out.println(" v = " + i + " m/s ==> estimated power consumption = " + est + " J/s");
System.out.println("=== === === === === ===");
}
System.out.println(" v = " + horizontalMaxVelocity() + " m/s ==> estimated power consumption = " + estimatePowerConsumption(horizontalMaxVelocity()) + " J/s");
System.out.println("=== === === === === ===");
first = false;
}
if(motor.isOn() && !route.isEmpty()) {
PositionVector position = new PositionVector(topologyComponent.getRealPosition());
PositionVector target = route.getFirst();
double distanceToTargetPosition = position.distanceTo(target);
// If target point is reached within a 1 meter margin, we remove that point from the list
if(distanceToTargetPosition < 0.1 || distanceToTargetPosition < currentSpeed)
{
target = route.removeFirst();
if(route.isEmpty()) {
// go to hover mode
topologyComponent.updateCurrentLocation(target.clone());
currentSpeed = 0;
motor.requestThrust(hoverThrustRequired());
PositionVector direction = topologyComponent.getCurrentDirection().clone();
direction.setEntry(2, 0);
topologyComponent.updateCurrentDirection(direction);
locationReached(topologyComponent.getCurrentLocation());
return;
}
else {
// get to speed
if(targetedSpeed > 0 && targetedSpeed < horizontalMaxVelocity()) {
motor.requestThrust(estimateRequiredThrust(targetedSpeed));
currentSpeed = targetedSpeed;
}
else {
motor.requestThrust(horizontalMaxVelocityRequiredTotalThrust());
currentSpeed = horizontalMaxVelocity();
}
long timeUntilReachedLocation = (long) (distanceToTargetPosition / currentSpeed) * Time.SECOND;
target = route.getFirst();
PositionVector directionToTarget = new PositionVector(target);
directionToTarget.subtract(position);
double timefactor = timeUntilReachedLocation / Time.SECOND;
directionToTarget.normalize();
topologyComponent.updateCurrentDirection(directionToTarget.clone());
directionToTarget.multiplyScalar(currentSpeed * timefactor);
PositionVector newPosition = new PositionVector(position);
newPosition.add(directionToTarget);
topologyComponent.updateCurrentLocation(newPosition);
if(timeUntilReachedLocation < timeBetweenMovementOperations) {
this.move(timeBetweenMovementOperations - timeUntilReachedLocation);
}
}
}
else {
double timefactor = timeBetweenMovementOperations / Time.SECOND;
motor.requestThrust(horizontalMaxVelocityRequiredTotalThrust());
currentSpeed = horizontalMaxVelocity();
PositionVector directionToTarget = new PositionVector(target);
directionToTarget.subtract(position);
directionToTarget.normalize();
if(directionToTarget.getX() != 0 || directionToTarget.getY() != 0) {
topologyComponent.updateCurrentDirection(directionToTarget.clone());
}
directionToTarget.multiplyScalar(currentSpeed * timefactor);
PositionVector newPosition = new PositionVector(position);
newPosition.add(directionToTarget);
topologyComponent.updateCurrentLocation(newPosition);
}
}
}
/*
*
*/
public double verticalDescentMaxThrust() {
// m * g - 0.5 * p * C * A * v^2
return hoverThrustRequired() - 0.5 * bodyDrag(0, new PositionVector(0,0,1)) * descentVelocityMax * descentVelocityMax;
}
public double verticalAscentMaxAcceleration() {
return (motor.getMaxThrust() - hoverThrustRequired()) / mass;
}
public double verticalAscentMaxVelocity() {
double maxThrust = motor.getMaxThrust();
return Math.sqrt(2.0 * (maxThrust - hoverThrustRequired()) / bodyDrag(0, new PositionVector(0,0,1)));
}
public double hoverThrustRequired() {
return mass * gravity;
}
public double horizontalMaxVelocity() {
double horizontalThrust = horizontalComponentMaxThrust();
double maxVelocity = Math.sqrt( (2.0 * horizontalThrust) / bodyDrag(maxPitchAngle, new PositionVector(1,0,0)));
return maxVelocity;
}
public double horizontalComponentMaxThrust() {
// hoverthrust / cos => amount of thrust in horizonal direction with °angle
double stableAltitudeMaximumTotalThrust = horizontalMaxVelocityRequiredTotalThrust();
// fraction of total thrust in horizonal (forward) direction with °angle
double maximumHorizontalThrustStableAltitude = stableAltitudeMaximumTotalThrust * Math.sin(maxPitchAngle);
return maximumHorizontalThrustStableAltitude;
}
public double horizontalMaxVelocityRequiredTotalThrust() {
return hoverThrustRequired() / Math.cos(maxPitchAngle);
}
public double bodyDrag(double angleRadians, PositionVector direction) {
return airdensity * dragCoefficient * areaExposedToDrag(angleRadians, direction);
}
public double areaExposedToDrag(double angleRadians, PositionVector direction) {
Vector2D v = new Vector2D(Math.abs(direction.getX()) + Math.abs(direction.getY()), Math.abs(direction.getZ()));
v = v.normalize();
double areaExposedFront = v.getX() * (Math.sin(angleRadians) * A_top + Math.cos(angleRadians) * A_front);
double areaExposedTop = v.getY() * (Math.cos(angleRadians) * A_top + Math.sin(angleRadians) * A_front);
return areaExposedFront + areaExposedTop;
}
/*
* F_drag [N] = 0.5 * p * C_drag * A * v^2
*/
public double currentDrag() {
return 0.5 * bodyDrag(currentAngleOfAttack, topologyComponent.getCurrentDirection()) * currentSpeed * currentSpeed;
}
/**
* Calculate the drag induced on the UAV with a given velocity and an angle of attack (in radians) moving forward horizontally.
*
* @param velocity
* @param angleInRadians
* @return
*/
private double forwardDrag(double velocity, double angleInRadians) {
return 0.5 * bodyDrag(angleInRadians, new PositionVector(1,0,0)) * velocity * velocity;
}
/*
*
*/
@Override
public void setMotorControl(StatelessMotorComponent motor) {
this.motor = motor;
}
@Override
public void setPreferredSpeed(double v_pref) {
this.targetedSpeed = v_pref;
}
@Override
public double getCurrentSpeed() {
return currentSpeed;
}
/**
* Trigger the callback function, if there is a valid callback
*
* @param position
*/
private void locationReached(PositionVector position) {
if(locationCallbacks.containsKey(position)) {
locationCallbacks.get(position).reachedLocation();
}
}
@Override
public void setTargetLocation(PositionVector target,
ReachedLocationCallback reachedLocationCallback) {
route.clear();
route.add(target);
if(reachedLocationCallback != null)
locationCallbacks.put(target, reachedLocationCallback);
}
@Override
public void setTargetLocationRoute(LinkedList route,
ReachedLocationCallback reachedLocationCallback) {
this.route.clear();
this.route.addAll(route);
if(reachedLocationCallback != null)
locationCallbacks.put(route.getLast(), reachedLocationCallback);
}
@Override
public void addTargetLocation(PositionVector target,
ReachedLocationCallback reachedLocationCallback) {
route.add(target);
if(reachedLocationCallback != null)
locationCallbacks.put(target, reachedLocationCallback);
}
@Override
public LinkedList getTargetLocations() {
LinkedList copy = new LinkedList<>();
for (PositionVector pv : route) {
copy.add(pv.clone());
}
return copy;
}
@Override
public void removeTargetLocations() {
route.clear();
locationCallbacks.clear();
}
@Override
public double minimumVelocity() {
return minimumHorizontalVelocity();
}
public double minimumHorizontalVelocity() {
return Math.sqrt(2 * hoverThrustRequired() * Math.tan(Math.toRadians(0.25)) / bodyDrag(Math.toRadians(0.25), new PositionVector(1,0,0)));
}
@Override
public double estimatePowerConsumption(double velocity) {
if(velocity == 0) {
return motor.estimatePowerConsumptionWatt(hoverThrustRequired());
}
else if(velocity > horizontalMaxVelocity()) {
return -1;
}
else if(velocity < minimumHorizontalVelocity()) {
return -1;
}
else {
System.out.println("===========================");
double estimateAngle = estimatePitchAngleForVelocity(velocity);
double estimatedDrag = forwardDrag(velocity, estimateAngle);
double requiredThrust = Math.sqrt(hoverThrustRequired() * hoverThrustRequired() + estimatedDrag * estimatedDrag);
double wattage = motor.estimatePowerConsumptionWatt(requiredThrust);
System.out.println("Motor requires " + wattage + " J/s at velocity " + velocity + " (Thrust: " + requiredThrust + " N, angle = " + Math.toDegrees(estimateAngle) + ", drag = "+ estimatedDrag+" N )");
return wattage;
}
}
private double estimateRequiredThrust(double velocity) {
if(velocity == 0) {
return motor.estimatePowerConsumptionWatt(hoverThrustRequired());
}
else if(velocity > horizontalMaxVelocity()) {
return -1;
}
else if(velocity < minimumHorizontalVelocity()) {
return -1;
}
else {
double estimateAngle = estimatePitchAngleForVelocity(velocity);
double estimatedDrag = forwardDrag(velocity, estimateAngle);
double requiredThrust = Math.sqrt(hoverThrustRequired() * hoverThrustRequired() + estimatedDrag * estimatedDrag);
return requiredThrust;
}
}
/**
* Estimate the pitch angle (angle of attack) required to get the target velocity.
* Angle precision is 1/4 degree.
*
* @param velocity
* @return
*/
private double estimatePitchAngleForVelocity(double velocity) {
int low = 0;
int high = Integer.MAX_VALUE;
double vsquared = (velocity * velocity);
for(int i = 0; i <= ((int) Math.toDegrees(maxPitchAngle)); i++) {
double v2 = 2 * hoverThrustRequired() * Math.tan(Math.toRadians(i)) / bodyDrag(Math.toRadians(i), new PositionVector(1,0,0));
if(v2 > vsquared && i < high) {
high = i;
}
else if(v2 < vsquared && i >= low) {
low = i;
}
else if(v2 == vsquared ) {
return Math.toRadians(i);
}
}
if(high < Integer.MAX_VALUE) {
double lo = low;
double hi = high;
double nearest = -1;
double nearestDiff = Double.MAX_VALUE;
double step = (hi - lo) / 4;
for(int i = 0; i < 4; i++) {
double d = lo + i * step;
double v2 = 2 * hoverThrustRequired() * Math.tan(Math.toRadians(d)) / bodyDrag(Math.toRadians(d), new PositionVector(1,0,0));
double diff = Math.abs(((velocity * velocity) - v2));
if(diff < nearestDiff || (lo == 0 && i == 1)) {
nearestDiff = diff;
nearest = d;
}
}
double n = Math.sqrt(2 * hoverThrustRequired() * Math.tan(Math.toRadians(nearest)) / bodyDrag(Math.toRadians(nearest), new PositionVector(1,0,0)));
System.out.println("target velocity = " + velocity + " m/s ==> AoA = " + nearest + "° // v_max = " + n + " m/s");
return Math.toRadians(nearest);
}
return maxPitchAngle;
}
}