simulation listener enhancements

ChangeLog

@@ -1,3 +1,11 @@
+2011-06-26  Sampo Niskanen
+
+	* [BUG] Original rocket was modified when sim.listener modified rocket
+
+2011-06-18  Sampo Niskanen
+
+	* Merged l10n branch into trunk, initial l10n support
+
 2011-06-10  Sampo Niskanen
 
 	* Released version 1.1.5

src-extra/AirStart.java

@@ -0,0 +1,21 @@
+import net.sf.openrocket.simulation.SimulationStatus;
+import net.sf.openrocket.simulation.exception.SimulationException;
+import net.sf.openrocket.simulation.listeners.AbstractSimulationListener;
+import net.sf.openrocket.util.Coordinate;
+
+/**
+ * Simulation listener that launches a rocket from a specific altitude.
+ */
+public class AirStart extends AbstractSimulationListener {
+	
+	/** Launch altitude */
+	private static final double ALTITUDE = 1000.0;
+	
+	@Override
+	public void startSimulation(SimulationStatus status) throws SimulationException {
+		Coordinate position = status.getRocketPosition();
+		position = position.add(0, 0, ALTITUDE);
+		status.setRocketPosition(position);
+	}
+	
+}

src/net/sf/openrocket/simulation/BasicEventSimulationEngine.java

@@ -61,8 +61,12 @@ public class BasicEventSimulationEngine implements SimulationEngine {
 		
 
 		SimulationListenerHelper.fireStartSimulation(status);
+		// Get originating position (in case listener has modified launch position)
+		Coordinate origin = status.getRocketPosition();
+		Coordinate originVelocity = status.getRocketVelocity();
 		
 		try {
+			double maxAlt = Double.NEGATIVE_INFINITY;
 			
 			// Start the simulation
 			while (handleEvents()) {
@@ -91,17 +95,24 @@ public class BasicEventSimulationEngine implements SimulationEngine {
 						status.getConfiguration().getRocket(),
 						new Pair<Double, Double>(oldAlt, status.getRocketPosition().z)));
 				
+				if (status.getRocketPosition().z > maxAlt) {
+					maxAlt = status.getRocketPosition().z;
+				}
+				
+
+				// Position relative to start location
+				Coordinate relativePosition = status.getRocketPosition().sub(origin);
 				
 				// Add appropriate events
 				if (!status.isLiftoff()) {
 					
 					// Avoid sinking into ground before liftoff
-					if (status.getRocketPosition().z < 0) {
+					if (relativePosition.z < 0) {
-						status.setRocketPosition(Coordinate.NUL);
+						status.setRocketPosition(origin);
-						status.setRocketVelocity(Coordinate.NUL);
+						status.setRocketVelocity(originVelocity);
 					}
 					// Detect lift-off
-					if (status.getRocketPosition().z > 0.01) {
+					if (relativePosition.z > 0.02) {
 						addEvent(new FlightEvent(FlightEvent.Type.LIFTOFF, status.getSimulationTime()));
 					}
 					
@@ -118,13 +129,13 @@ public class BasicEventSimulationEngine implements SimulationEngine {
 				
 				// Check for launch guide clearance
 				if (!status.isLaunchRodCleared() &&
-						status.getRocketPosition().length() > status.getSimulationConditions().getLaunchRodLength()) {
+						relativePosition.length() > status.getSimulationConditions().getLaunchRodLength()) {
 					addEvent(new FlightEvent(FlightEvent.Type.LAUNCHROD, status.getSimulationTime(), null));
 				}
 				
 
 				// Check for apogee
-				if (!status.isApogeeReached() && status.getRocketPosition().z < oldAlt - 0.001) {
+				if (!status.isApogeeReached() && status.getRocketPosition().z < maxAlt - 0.01) {
 					addEvent(new FlightEvent(FlightEvent.Type.APOGEE, status.getSimulationTime(),
 							status.getConfiguration().getRocket()));
 				}

src/net/sf/openrocket/simulation/GUISimulationConditions.java

@@ -436,7 +436,7 @@ public class GUISimulationConditions implements ChangeSource, Cloneable {
 	public SimulationConditions toSimulationConditions() {
 		SimulationConditions conditions = new SimulationConditions();
 		
-		conditions.setRocket(getRocket());
+		conditions.setRocket((Rocket) getRocket().copy());
 		conditions.setMotorConfigurationID(getMotorConfigurationID());
 		conditions.setLaunchRodLength(getLaunchRodLength());
 		conditions.setLaunchRodAngle(getLaunchRodAngle());

src/net/sf/openrocket/simulation/listeners/example/AirStart.java

@@ -0,0 +1,38 @@
+package net.sf.openrocket.simulation.listeners.example;
+
+import net.sf.openrocket.simulation.SimulationStatus;
+import net.sf.openrocket.simulation.exception.SimulationException;
+import net.sf.openrocket.simulation.listeners.AbstractSimulationListener;
+import net.sf.openrocket.util.Coordinate;
+
+/**
+ * Simulation listener that launches a rocket from a specific altitude.
+ * <p>
+ * The altitude is read from the system property "openrocket.airstart.altitude"
+ * if defined, otherwise a default altitude of 1000 meters is used.
+ */
+public class AirStart extends AbstractSimulationListener {
+	
+	/** Default launch altitude */
+	private static final double DEFAULT_ALTITUDE = 1000.0;
+	
+	@Override
+	public void startSimulation(SimulationStatus status) throws SimulationException {
+		
+		// Get the launch altitude
+		double altitude;
+		String arg = System.getProperty("openrocket.airstart.altitude");
+		try {
+			altitude = Double.parseDouble(arg);
+		} catch (RuntimeException e) {
+			altitude = DEFAULT_ALTITUDE;
+		}
+		
+		// Modify launch position
+		Coordinate position = status.getRocketPosition();
+		position = position.add(0, 0, altitude);
+		status.setRocketPosition(position);
+		
+	}
+	
+}

src/net/sf/openrocket/simulation/listeners/example/RollControlListener.java

@@ -1,10 +1,13 @@
-package net.sf.openrocket.simulation.listeners.haisu;
+package net.sf.openrocket.simulation.listeners.example;
 
 import net.sf.openrocket.aerodynamics.FlightConditions;
 import net.sf.openrocket.rocketcomponent.FinSet;
 import net.sf.openrocket.rocketcomponent.RocketComponent;
+import net.sf.openrocket.simulation.FlightDataType;
 import net.sf.openrocket.simulation.SimulationStatus;
+import net.sf.openrocket.simulation.exception.SimulationException;
 import net.sf.openrocket.simulation.listeners.AbstractSimulationListener;
+import net.sf.openrocket.unit.UnitGroup;
 import net.sf.openrocket.util.MathUtil;
 
 /**
@@ -15,15 +18,29 @@ import net.sf.openrocket.util.MathUtil;
  */
 public class RollControlListener extends AbstractSimulationListener {
 	
-	private static final double DELTA_T = 0.01;
+	// Name of control fin set
+	private static final String CONTROL_FIN_NAME = "CONTROL";
+	
+	// Define custom flight data type
+	private static final FlightDataType FIN_CANT_TYPE = FlightDataType.getType("Control fin cant",
+			UnitGroup.UNITS_ANGLE);
+	
+	// Simulation time at which PID controller is activated
 	private static final double START_TIME = 0.5;
 	
+	// Desired roll rate (rad/sec)
 	private static final double SETPOINT = 0.0;
 	
-	private static final double TURNRATE = 10 * Math.PI / 180; // per second
+	// Maximum control fin turn rate (rad/sec)
+	private static final double TURNRATE = 10 * Math.PI / 180;
+	
+	// Maximum control fin angle (rad)
+	private static final double MAX_ANGLE = 15 * Math.PI / 180;
 	
 
 	/*
+	 * PID parameters
+	 * 
 	 * At M=0.3 KP oscillation threshold between 0.35 and 0.4.    Good KI=3
 	 * At M=0.6 KP oscillation threshold between 0.07 and 0.08    Good KI=2
 	 * At M=0.9 KP oscillation threshold between 0.013 and 0.014  Good KI=0.5
@@ -32,58 +49,63 @@ public class RollControlListener extends AbstractSimulationListener {
 	private static final double KI = 0.2;
 	
 
-	private static final double MAX_ANGLE = 15 * Math.PI / 180;
-	
-
 
 
 	private double rollrate;
 	
+	private double prevTime = 0;
 	private double intState = 0;
 	
 	private double finPosition = 0;
 	
 	
-	public RollControlListener() {
-	}
 
 	@Override
 	public FlightConditions postFlightConditions(SimulationStatus status, FlightConditions flightConditions) {
+		// Store the current roll rate for later use
 		rollrate = flightConditions.getRollRate();
 		return null;
 	}
 	
+	
 	@Override
-	public void postStep(SimulationStatus status) {
+	public void postStep(SimulationStatus status) throws SimulationException {
 		
-		if (status.getSimulationTime() < START_TIME)
+		// Activate PID controller only after a specific time
+		if (status.getSimulationTime() < START_TIME) {
+			prevTime = status.getSimulationTime();
 			return;
+		}
 		
-		// PID controller
+		// Find the fin set named CONTROL
 		FinSet finset = null;
 		for (RocketComponent c : status.getConfiguration()) {
-			if ((c instanceof FinSet) && (c.getName().equals("CONTROL"))) {
+			if ((c instanceof FinSet) && (c.getName().equals(CONTROL_FIN_NAME))) {
 				finset = (FinSet) c;
 				break;
 			}
 		}
 		if (finset == null) {
-			throw new RuntimeException("CONTROL fin not found");
+			throw new SimulationException("A fin set with name '" + CONTROL_FIN_NAME + "' was not found");
 		}
 		
 
+		// Determine time step
+		double deltaT = status.getSimulationTime() - prevTime;
+		prevTime = status.getSimulationTime();
+		
+
+		// PID controller
 		double error = SETPOINT - rollrate;
 		
-
-		error = Math.signum(error) * error * error; ////  pow2(error)
-		
 		double p = KP * error;
-		intState += error * DELTA_T;
+		intState += error * deltaT;
 		double i = KI * intState;
 		
 		double value = p + i;
 		
 
+		// Clamp the fin angle between -MAX_ANGLE and MAX_ANGLE
 		if (Math.abs(value) > MAX_ANGLE) {
 			System.err.printf("Attempting to set angle %.1f at t=%.3f, clamping.\n",
 					value * 180 / Math.PI, status.getSimulationTime());
@@ -91,19 +113,16 @@ public class RollControlListener extends AbstractSimulationListener {
 		}
 		
 
+		// Limit the fin turn rate
 		if (finPosition < value) {
-			finPosition = Math.min(finPosition + TURNRATE * DELTA_T, value);
+			finPosition = Math.min(finPosition + TURNRATE * deltaT, value);
 		} else {
-			finPosition = Math.max(finPosition - TURNRATE * DELTA_T, value);
+			finPosition = Math.max(finPosition - TURNRATE * deltaT, value);
-		}
-		
-		if (MathUtil.equals(status.getSimulationTime() * 10, Math.rint(status.getSimulationTime() * 10))) {
-			System.err.printf("t=%.3f  angle=%.1f  current=%.1f\n", status.getSimulationTime(),
-					value * 180 / Math.PI, finPosition * 180 / Math.PI);
 		}
 		
+		// Set the control fin cant and store the data
 		finset.setCantAngle(finPosition);
+		status.getFlightData().setValue(FIN_CANT_TYPE, finPosition);
 		
 	}
-	
 }