launchdetector: return state of detection

The launchdetector now has a intermediate state (controlsenabled) which
is meant to be interpreted by the controller as: "perform attitude
control but do not yet power up the motor". This can be used in the
floating phase during a bungee launch for example.

src/lib/launchdetection/CatapultLaunchMethod.cpp

@@ -49,10 +49,10 @@ CatapultLaunchMethod::CatapultLaunchMethod(SuperBlock *parent) :
 	SuperBlock(parent, "CAT"),
 	last_timestamp(hrt_absolute_time()),
 	integrator(0.0f),
-	launchDetected(false),
-	threshold_accel(this, "A"),
-	threshold_time(this, "T"),
-	delay(this, "DELAY")
+	state(LAUNCHDETECTION_RES_NONE),
+	thresholdAccel(this, "A"),
+	thresholdTime(this, "T"),
+	motorDelay(this, "MDEL")
 {
 
 }
@@ -66,46 +66,56 @@ void CatapultLaunchMethod::update(float accel_x)
 	float dt = (float)hrt_elapsed_time(&last_timestamp) * 1e-6f;
 	last_timestamp = hrt_absolute_time();
 
-	if (accel_x > threshold_accel.get()) {
-		integrator += dt;
-//		warnx("*** integrator %.3f, threshold_accel %.3f, threshold_time %.3f, accel_x %.3f, dt %.3f",
-//				(double)integrator, (double)threshold_accel.get(),  (double)threshold_time.get(), (double)accel_x, (double)dt);
-		if (integrator > threshold_time.get()) {
-			launchDetected = true;
+	switch (state) {
+	case LAUNCHDETECTION_RES_NONE:
+		/* Detect a acceleration that is longer and stronger as the minimum given by the params */
+		if (accel_x > thresholdAccel.get()) {
+			integrator += dt;
+			if (integrator > thresholdTime.get()) {
+				if (motorDelay.get() > 0.0f) {
+					state = LAUNCHDETECTION_RES_DETECTED_ENABLECONTROL;
+					warnx("Launch detected: state: enablecontrol, waiting %.2fs until using full"
+							" throttle", (double)motorDelay.get());
+				} else {
+					/* No motor delay set: go directly to enablemotors state */
+					state = LAUNCHDETECTION_RES_DETECTED_ENABLEMOTORS;
+					warnx("Launch detected: state: enablemotors (delay not activated)");
+				}
+			}
+		} else {
+			/* reset */
+			reset();
 		}
+		break;
 
-	} else {
-//		warnx("integrator %.3f, threshold_accel %.3f, threshold_time %.3f, accel_x %.3f, dt %.3f",
-//				(double)integrator, (double)threshold_accel.get(),  (double)threshold_time.get(), (double)accel_x, (double)dt);
-		/* reset integrator */
-		integrator = 0.0f;
-	}
-
-	if (launchDetected) {
-		delayCounter += dt;
-		if (delayCounter > delay.get()) {
-			delayPassed = true;
+	case LAUNCHDETECTION_RES_DETECTED_ENABLECONTROL:
+		/* Vehicle is currently controlling attitude but not with full throttle. Waiting undtil delay is
+		 * over to allow full throttle */
+		motorDelayCounter += dt;
+		if (motorDelayCounter > motorDelay.get()) {
+			warnx("Launch detected: state enablemotors");
+			state = LAUNCHDETECTION_RES_DETECTED_ENABLEMOTORS;
 		}
+		break;
+
+	default:
+		break;
+
 	}
 
 }
 
-bool CatapultLaunchMethod::getLaunchDetected()
+LaunchDetectionResult CatapultLaunchMethod::getLaunchDetected() const
 {
-	if (delay.get() > 0.0f) {
-		return delayPassed;
-	} else {
-		return launchDetected;
-	}
+	return state;
 }
 
 
 void CatapultLaunchMethod::reset()
 {
 	integrator = 0.0f;
-	delayCounter = 0.0f;
-	launchDetected = false;
-	delayPassed = false;
+	motorDelayCounter = 0.0f;
+	state = LAUNCHDETECTION_RES_NONE;
 }
 
 }

src/lib/launchdetection/CatapultLaunchMethod.h

@@ -57,20 +57,19 @@ public:
 	~CatapultLaunchMethod();
 
 	void update(float accel_x);
-	bool getLaunchDetected();
+	LaunchDetectionResult getLaunchDetected() const;
 	void reset();
 
 private:
 	hrt_abstime last_timestamp;
 	float integrator;
-	float delayCounter;
+	float motorDelayCounter;
 
-	bool launchDetected;
-	bool delayPassed;
+	LaunchDetectionResult state;
 
-	control::BlockParamFloat threshold_accel;
-	control::BlockParamFloat threshold_time;
-	control::BlockParamFloat delay;
+	control::BlockParamFloat thresholdAccel;
+	control::BlockParamFloat thresholdTime;
+	control::BlockParamFloat motorDelay;
 
 };
 

src/lib/launchdetection/LaunchDetector.cpp

@@ -46,6 +46,7 @@ namespace launchdetection
 
 LaunchDetector::LaunchDetector() :
 	SuperBlock(NULL, "LAUN"),
+	activeLaunchDetectionMethodIndex(-1),
 	launchdetection_on(this, "ALL_ON"),
 	throttlePreTakeoff(this, "THR_PRE")
 {
@@ -65,7 +66,14 @@ LaunchDetector::~LaunchDetector()
 void LaunchDetector::reset()
 {
 	/* Reset all detectors */
-	launchMethods[0]->reset();
+	for (uint8_t i = 0; i < sizeof(launchMethods)/sizeof(LaunchMethod); i++) {
+		launchMethods[i]->reset();
+	}
+
+	/* Reset active launchdetector */
+	activeLaunchDetectionMethodIndex  = -1;
+
+
 }
 
 void LaunchDetector::update(float accel_x)
@@ -77,17 +85,24 @@ void LaunchDetector::update(float accel_x)
 	}
 }
 
-bool LaunchDetector::getLaunchDetected()
+LaunchDetectionResult LaunchDetector::getLaunchDetected()
 {
 	if (launchdetection_on.get() == 1) {
-		for (uint8_t i = 0; i < sizeof(launchMethods)/sizeof(LaunchMethod); i++) {
-			if(launchMethods[i]->getLaunchDetected()) {
-				return true;
+		if (activeLaunchDetectionMethodIndex < 0) {
+		/* None of the active launchmethods has detected a launch, check all launchmethods */
+			for (uint8_t i = 0; i < sizeof(launchMethods)/sizeof(LaunchMethod); i++) {
+				if(launchMethods[i]->getLaunchDetected() != LAUNCHDETECTION_RES_NONE) {
+					warnx("selecting launchmethod %d", i);
+					activeLaunchDetectionMethodIndex = i; // from now on only check this method
+					return launchMethods[i]->getLaunchDetected();
+				}
 			}
+		} else {
+			return launchMethods[activeLaunchDetectionMethodIndex]->getLaunchDetected();
 		}
 	}
 
-	return false;
+	return LAUNCHDETECTION_RES_NONE;
 }
 
 }

src/lib/launchdetection/LaunchDetector.h

@@ -59,7 +59,7 @@ public:
 	void reset();
 
 	void update(float accel_x);
-	bool getLaunchDetected();
+	LaunchDetectionResult getLaunchDetected();
 	bool launchDetectionEnabled() { return (bool)launchdetection_on.get(); };
 
 	float getThrottlePreTakeoff() {return throttlePreTakeoff.get(); }
@@ -67,6 +67,12 @@ public:
 //	virtual bool getLaunchDetected();
 protected:
 private:
+	int activeLaunchDetectionMethodIndex; /**< holds a index to the launchMethod in the array launchMethods
+					       which detected a Launch. If no launchMethod has detected a launch yet the
+					       value is -1. Once one launchMetthod has detected a launch only this
+					       method is checked for further adavancing in the state machine (e.g. when
+					       to power up the motors) */
+
 	LaunchMethod* launchMethods[1];
 	control::BlockParamInt launchdetection_on;
 	control::BlockParamFloat throttlePreTakeoff;

src/lib/launchdetection/LaunchMethod.h

@@ -44,11 +44,22 @@
 namespace launchdetection
 {
 
+enum LaunchDetectionResult {
+	LAUNCHDETECTION_RES_NONE = 0, /**< No launch has been detected */
+	LAUNCHDETECTION_RES_DETECTED_ENABLECONTROL = 1, /**< Launch has been detected, the controller should
+							  control the attitude. However any motors should not throttle
+							  up and still be set to 'throttlePreTakeoff'.
+							  For instance this is used to have a delay for the motor
+							  when launching a fixed wing aircraft from a bungee */
+	LAUNCHDETECTION_RES_DETECTED_ENABLEMOTORS = 2 /**< Launch has been detected, teh controller should control
+							attitude and also throttle up the motors. */
+};
+
 class LaunchMethod
 {
 public:
 	virtual void update(float accel_x) = 0;
-	virtual bool getLaunchDetected() = 0;
+	virtual LaunchDetectionResult getLaunchDetected() const = 0;
 	virtual void reset() = 0;
 
 protected:

src/lib/launchdetection/launchdetection_params.c

@@ -78,14 +78,16 @@ PARAM_DEFINE_FLOAT(LAUN_CAT_A, 30.0f);
 PARAM_DEFINE_FLOAT(LAUN_CAT_T, 0.05f);
 
 /**
- * Catapult delay
- *
+ * Motor delay
  *
+ * Delay between starting attitude control and powering up the thorttle (giving throttle control to the controller)
+ * Before this timespan is up the throttle will be set to LAUN_THR_PRE, set to 0 to deactivate
  *
+ * @unit seconds
  * @min 0
  * @group Launch detection
  */
-PARAM_DEFINE_FLOAT(LAUN_CAT_DELAY, 0.0f);
+PARAM_DEFINE_FLOAT(LAUN_CAT_MDEL, 0.0f);
 /**
  * Throttle setting while detecting launch.
  *