Merge remote-tracking branch 'thomasgubler_private/fw_autoland_att_tecs' into navigator_wip_merge_test

Conflicts:
	src/modules/fw_pos_control_l1/fw_pos_control_l1_main.cpp

9 files changed, 381 insertions, 118 deletions

diff --git a/src/lib/ecl/attitude_fw/ecl_pitch_controller.cpp b/src/lib/ecl/attitude_fw/ecl_pitch_controller.cpp
index 2eb58abd6..d7dbbebd4 100644
--- a/src/lib/ecl/attitude_fw/ecl_pitch_controller.cpp
+++ b/src/lib/ecl/attitude_fw/ecl_pitch_controller.cpp
@@ -45,39 +45,30 @@
 #include <geo/geo.h>
 #include <ecl/ecl.h>
 #include <mathlib/mathlib.h>
+#include <systemlib/err.h>
 
 ECL_PitchController::ECL_PitchController() :
 	_last_run(0),
+	_tc(0.1f),
+	_k_p(0.0f),
+	_k_i(0.0f),
+	_k_d(0.0f),
+	_k_ff(0.0f),
+	_integrator_max(0.0f),
+	_max_rate_pos(0.0f),
+	_max_rate_neg(0.0f),
+	_roll_ff(0.0f),
 	_last_output(0.0f),
 	_integrator(0.0f),
 	_rate_error(0.0f),
 	_rate_setpoint(0.0f),
-	_max_deflection_rad(math::radians(45.0f))
+	_bodyrate_setpoint(0.0f)
 {
 }
 
-float ECL_PitchController::control(float pitch_setpoint, float pitch, float pitch_rate, float roll, float scaler,
-				   bool lock_integrator, float airspeed_min, float airspeed_max, float airspeed)
+float ECL_PitchController::control_attitude(float pitch_setpoint, float roll, float pitch, float airspeed)
 {
-	/* get the usual dt estimate */
-	uint64_t dt_micros = ecl_elapsed_time(&_last_run);
-	_last_run = ecl_absolute_time();
-	float dt = (float)dt_micros * 1e-6f;
-
-	/* lock integral for long intervals */
-	if (dt_micros > 500000)
-		lock_integrator = true;
 
-	float k_roll_ff = math::max((_k_p - _k_i * _tc) * _tc - _k_d, 0.0f);
-	float k_i_rate = _k_i * _tc;
-
-	/* input conditioning */
-	if (!isfinite(airspeed)) {
-		/* airspeed is NaN, +- INF or not available, pick center of band */
-		airspeed = 0.5f * (airspeed_min + airspeed_max);
-	} else if (airspeed < airspeed_min) {
-		airspeed = airspeed_min;
-	}
 
 	/* flying inverted (wings upside down) ? */
 	bool inverted = false;
@@ -105,29 +96,72 @@ float ECL_PitchController::control(float pitch_setpoint, float pitch, float pitc
 	if (inverted)
 		turn_offset = -turn_offset;
 
+	/* Calculate the error */
 	float pitch_error = pitch_setpoint - pitch;
-	/* rate setpoint from current error and time constant */
-	_rate_setpoint = pitch_error / _tc;
+
+	/*  Apply P controller: rate setpoint from current error and time constant */
+	_rate_setpoint =  pitch_error / _tc;
 
 	/* add turn offset */
 	_rate_setpoint += turn_offset;
 
-	_rate_error = _rate_setpoint - pitch_rate;
+	/* limit the rate */ //XXX: move to body angluar rates
+	if (_max_rate_pos > 0.01f && _max_rate_neg > 0.01f) {
+		if (_rate_setpoint > 0.0f) {
+			_rate_setpoint = (_rate_setpoint > _max_rate_pos) ? _max_rate_pos : _rate_setpoint;
+		} else {
+			_rate_setpoint = (_rate_setpoint < -_max_rate_neg) ? -_max_rate_neg : _rate_setpoint;
+		}
 
-	float ilimit_scaled = _integrator_max * scaler;
+	}
 
-	if (!lock_integrator && k_i_rate > 0.0f && airspeed > 0.5f * airspeed_min) {
+	return _rate_setpoint;
+}
 
-		float id = _rate_error * k_i_rate * dt * scaler;
+float ECL_PitchController::control_bodyrate(float roll, float pitch,
+		float pitch_rate, float yaw_rate,
+		float yaw_rate_setpoint,
+		float airspeed_min, float airspeed_max, float airspeed, float scaler, bool lock_integrator)
+{
+	/* get the usual dt estimate */
+	uint64_t dt_micros = ecl_elapsed_time(&_last_run);
+	_last_run = ecl_absolute_time();
+	float dt = (float)dt_micros * 1e-6f;
+
+	/* lock integral for long intervals */
+	if (dt_micros > 500000)
+		lock_integrator = true;
+
+//	float k_ff = math::max((_k_p - _k_i * _tc) * _tc - _k_d, 0.0f);
+	float k_ff = 0;
+
+	/* input conditioning */
+	if (!isfinite(airspeed)) {
+		/* airspeed is NaN, +- INF or not available, pick center of band */
+		airspeed = 0.5f * (airspeed_min + airspeed_max);
+	} else if (airspeed < airspeed_min) {
+		airspeed = airspeed_min;
+	}
+
+	/* Transform setpoint to body angular rates */
+	_bodyrate_setpoint = cosf(roll) * _rate_setpoint + cosf(pitch) * sinf(roll) * yaw_rate_setpoint; //jacobian
+
+	/* Transform estimation to body angular rates */
+	float pitch_bodyrate = cosf(roll) * pitch_rate + cosf(pitch) * sinf(roll) * yaw_rate; //jacobian
+
+	_rate_error = _bodyrate_setpoint - pitch_bodyrate;
+
+	if (!lock_integrator && _k_i > 0.0f && airspeed > 0.5f * airspeed_min) {
+
+		float id = _rate_error * dt;
 
 		/*
-		 * anti-windup: do not allow integrator to increase into the
-		 * wrong direction if actuator is at limit
+		 * anti-windup: do not allow integrator to increase if actuator is at limit
 		 */
-		if (_last_output < -_max_deflection_rad) {
+		if (_last_output < -1.0f) {
 			/* only allow motion to center: increase value */
 			id = math::max(id, 0.0f);
-		} else if (_last_output > _max_deflection_rad) {
+		} else if (_last_output > 1.0f) {
 			/* only allow motion to center: decrease value */
 			id = math::min(id, 0.0f);
 		}
@@ -136,11 +170,14 @@ float ECL_PitchController::control(float pitch_setpoint, float pitch, float pitc
 	}
 
 	/* integrator limit */
-	_integrator = math::constrain(_integrator, -ilimit_scaled, ilimit_scaled);
-	/* store non-limited output */
-	_last_output = ((_rate_error * _k_d * scaler) + _integrator + (_rate_setpoint * k_roll_ff)) * scaler;
-
-	return math::constrain(_last_output, -_max_deflection_rad, _max_deflection_rad);
+	//xxx: until start detection is available: integral part in control signal is limited here
+	float integrator_constrained = math::constrain(_integrator * _k_i, -_integrator_max, _integrator_max);
+
+	/* Apply PI rate controller and store non-limited output */
+	_last_output = (_bodyrate_setpoint * _k_ff +_rate_error * _k_p + integrator_constrained + _rate_setpoint * k_ff) * scaler * scaler;  //scaler is proportional to 1/airspeed
+//	warnx("pitch: _integrator: %.4f, _integrator_max: %.4f, airspeed %.4f, _k_i %.4f, _k_p: %.4f", (double)_integrator, (double)_integrator_max, (double)airspeed, (double)_k_i, (double)_k_p);
+//	warnx("roll: _last_output %.4f", (double)_last_output);
+	return math::constrain(_last_output, -1.0f, 1.0f);
 }
 
 void ECL_PitchController::reset_integrator()
diff --git a/src/lib/ecl/attitude_fw/ecl_pitch_controller.h b/src/lib/ecl/attitude_fw/ecl_pitch_controller.h
index 1e6cec6a1..2ca0490fd 100644
--- a/src/lib/ecl/attitude_fw/ecl_pitch_controller.h
+++ b/src/lib/ecl/attitude_fw/ecl_pitch_controller.h
@@ -36,6 +36,7 @@
  * Definition of a simple orthogonal pitch PID controller.
  *
  * @author Lorenz Meier <lm@inf.ethz.ch>
+ * @author Thomas Gubler <thomasgubler@gmail.com>
  *
  * Acknowledgements:
  *
@@ -51,13 +52,18 @@
 #include <stdbool.h>
 #include <stdint.h>
 
-class __EXPORT ECL_PitchController
+class __EXPORT ECL_PitchController //XXX: create controller superclass
 {
 public:
 	ECL_PitchController();
 
-	float control(float pitch_setpoint, float pitch, float pitch_rate, float roll, float scaler = 1.0f,
-		      bool lock_integrator = false, float airspeed_min = 0.0f, float airspeed_max = 0.0f, float airspeed = (0.0f / 0.0f));
+	float control_attitude(float pitch_setpoint, float roll, float pitch, float airspeed);
+
+
+	float control_bodyrate(float roll, float pitch,
+			float pitch_rate, float yaw_rate,
+			float yaw_rate_setpoint,
+			float airspeed_min = 0.0f, float airspeed_max = 0.0f, float airspeed = (0.0f / 0.0f), float scaler = 1.0f, bool lock_integrator = false);
 
 	void reset_integrator();
 
@@ -67,21 +73,30 @@ public:
 	void set_k_p(float k_p) {
 		_k_p = k_p;
 	}
+
 	void set_k_i(float k_i) {
 		_k_i = k_i;
 	}
 	void set_k_d(float k_d) {
 		_k_d = k_d;
 	}
+
+	void set_k_ff(float k_ff) {
+		_k_ff = k_ff;
+	}
+
 	void set_integrator_max(float max) {
 		_integrator_max = max;
 	}
+
 	void set_max_rate_pos(float max_rate_pos) {
 		_max_rate_pos = max_rate_pos;
 	}
+
 	void set_max_rate_neg(float max_rate_neg) {
 		_max_rate_neg = max_rate_neg;
 	}
+
 	void set_roll_ff(float roll_ff) {
 		_roll_ff = roll_ff;
 	}
@@ -94,6 +109,10 @@ public:
 		return _rate_setpoint;
 	}
 
+	float get_desired_bodyrate() {
+		return _bodyrate_setpoint;
+	}
+
 private:
 
 	uint64_t _last_run;
@@ -101,6 +120,7 @@ private:
 	float _k_p;
 	float _k_i;
 	float _k_d;
+	float _k_ff;
 	float _integrator_max;
 	float _max_rate_pos;
 	float _max_rate_neg;
@@ -109,7 +129,7 @@ private:
 	float _integrator;
 	float _rate_error;
 	float _rate_setpoint;
-	float _max_deflection_rad;
+	float _bodyrate_setpoint;
 };
 
 #endif // ECL_PITCH_CONTROLLER_H
diff --git a/src/lib/ecl/attitude_fw/ecl_roll_controller.cpp b/src/lib/ecl/attitude_fw/ecl_roll_controller.cpp
index 0b1ffa7a4..bd6c9da71 100644
--- a/src/lib/ecl/attitude_fw/ecl_roll_controller.cpp
+++ b/src/lib/ecl/attitude_fw/ecl_roll_controller.cpp
@@ -45,21 +45,47 @@
 #include <geo/geo.h>
 #include <ecl/ecl.h>
 #include <mathlib/mathlib.h>
+#include <systemlib/err.h>
 
 ECL_RollController::ECL_RollController() :
 	_last_run(0),
 	_tc(0.1f),
+	_k_p(0.0f),
+	_k_i(0.0f),
+	_k_d(0.0f),
+	_k_ff(0.0f),
+	_integrator_max(0.0f),
+	_max_rate(0.0f),
 	_last_output(0.0f),
 	_integrator(0.0f),
 	_rate_error(0.0f),
 	_rate_setpoint(0.0f),
-	_max_deflection_rad(math::radians(45.0f))
+	_bodyrate_setpoint(0.0f)
 {
+}
+
+float ECL_RollController::control_attitude(float roll_setpoint, float roll)
+{
+
+	/* Calculate error */
+	float roll_error = roll_setpoint - roll;
+
+	/* Apply P controller */
+	_rate_setpoint = roll_error / _tc;
+
+	/* limit the rate */ //XXX: move to body angluar rates
+	if (_max_rate > 0.01f) {
+		_rate_setpoint = (_rate_setpoint > _max_rate) ? _max_rate : _rate_setpoint;
+		_rate_setpoint = (_rate_setpoint < -_max_rate) ? -_max_rate : _rate_setpoint;
+	}
 
+	return _rate_setpoint;
 }
 
-float ECL_RollController::control(float roll_setpoint, float roll, float roll_rate,
-				  float scaler, bool lock_integrator, float airspeed_min, float airspeed_max, float airspeed)
+float ECL_RollController::control_bodyrate(float pitch,
+		float roll_rate, float yaw_rate,
+		float yaw_rate_setpoint,
+		float airspeed_min, float airspeed_max, float airspeed, float scaler, bool lock_integrator)
 {
 	/* get the usual dt estimate */
 	uint64_t dt_micros = ecl_elapsed_time(&_last_run);
@@ -70,10 +96,11 @@ float ECL_RollController::control(float roll_setpoint, float roll, float roll_ra
 	if (dt_micros > 500000)
 		lock_integrator = true;
 
-	float k_ff = math::max((_k_p - _k_i * _tc) * _tc - _k_d, 0.0f);
-	float k_i_rate = _k_i * _tc;
+//	float k_ff = math::max((_k_p - _k_i * _tc) * _tc - _k_d, 0.0f);
+	float k_ff = 0; //xxx: param
 
 	/* input conditioning */
+//	warnx("airspeed pre %.4f", (double)airspeed);
 	if (!isfinite(airspeed)) {
 		/* airspeed is NaN, +- INF or not available, pick center of band */
 		airspeed = 0.5f * (airspeed_min + airspeed_max);
@@ -81,32 +108,27 @@ float ECL_RollController::control(float roll_setpoint, float roll, float roll_ra
 		airspeed = airspeed_min;
 	}
 
-	float roll_error = roll_setpoint - roll;
-	_rate_setpoint = roll_error / _tc;
-
-	/* limit the rate */
-	if (_max_rate > 0.01f) {
-		_rate_setpoint = (_rate_setpoint > _max_rate) ? _max_rate : _rate_setpoint;
-		_rate_setpoint = (_rate_setpoint < -_max_rate) ? -_max_rate : _rate_setpoint;
-	}
 
-	_rate_error = _rate_setpoint - roll_rate;
+	/* Transform setpoint to body angular rates */
+	_bodyrate_setpoint = _rate_setpoint - sinf(pitch) * yaw_rate_setpoint; //jacobian
 
+	/* Transform estimation to body angular rates */
+	float roll_bodyrate = roll_rate - sinf(pitch) * yaw_rate; //jacobian
 
-	float ilimit_scaled = _integrator_max * scaler;
+	/* Calculate body angular rate error */
+	_rate_error = _bodyrate_setpoint - roll_bodyrate; //body angular rate error
 
-	if (!lock_integrator && k_i_rate > 0.0f && airspeed > 0.5f * airspeed_min) {
+	if (!lock_integrator && _k_i > 0.0f && airspeed > 0.5f * airspeed_min) {
 
-		float id = _rate_error * k_i_rate * dt * scaler;
+		float id = _rate_error * dt;
 
 		/*
-		 * anti-windup: do not allow integrator to increase into the
-		 * wrong direction if actuator is at limit
+		 * anti-windup: do not allow integrator to increase if actuator is at limit
 		 */
-		if (_last_output < -_max_deflection_rad) {
+		if (_last_output < -1.0f) {
 			/* only allow motion to center: increase value */
 			id = math::max(id, 0.0f);
-		} else if (_last_output > _max_deflection_rad) {
+		} else if (_last_output > 1.0f) {
 			/* only allow motion to center: decrease value */
 			id = math::min(id, 0.0f);
 		}
@@ -115,11 +137,14 @@ float ECL_RollController::control(float roll_setpoint, float roll, float roll_ra
 	}
 
 	/* integrator limit */
-	_integrator = math::constrain(_integrator, -ilimit_scaled, ilimit_scaled);
-	/* store non-limited output */
-	_last_output = ((_rate_error * _k_d * scaler) + _integrator + (_rate_setpoint * k_ff)) * scaler;
+	//xxx: until start detection is available: integral part in control signal is limited here
+	float integrator_constrained = math::constrain(_integrator * _k_i, -_integrator_max, _integrator_max);
+	//warnx("roll: _integrator: %.4f, _integrator_max: %.4f", (double)_integrator, (double)_integrator_max);
+
+	/* Apply PI rate controller and store non-limited output */
+	_last_output = (_bodyrate_setpoint * _k_ff + _rate_error * _k_p + integrator_constrained + _rate_setpoint * k_ff) * scaler * scaler;  //scaler is proportional to 1/airspeed
 
-	return math::constrain(_last_output, -_max_deflection_rad, _max_deflection_rad);
+	return math::constrain(_last_output, -1.0f, 1.0f);
 }
 
 void ECL_RollController::reset_integrator()
diff --git a/src/lib/ecl/attitude_fw/ecl_roll_controller.h b/src/lib/ecl/attitude_fw/ecl_roll_controller.h
index 0d4ea9333..efc7b8944 100644
--- a/src/lib/ecl/attitude_fw/ecl_roll_controller.h
+++ b/src/lib/ecl/attitude_fw/ecl_roll_controller.h
@@ -36,6 +36,7 @@
  * Definition of a simple orthogonal roll PID controller.
  *
  * @author Lorenz Meier <lm@inf.ethz.ch>
+ * @author Thomas Gubler <thomasgubler@gmail.com>
  *
  * Acknowledgements:
  *
@@ -51,13 +52,17 @@
 #include <stdbool.h>
 #include <stdint.h>
 
-class __EXPORT ECL_RollController
+class __EXPORT ECL_RollController //XXX: create controller superclass
 {
 public:
 	ECL_RollController();
 
-	float control(float roll_setpoint, float roll, float roll_rate,
-		      float scaler = 1.0f, bool lock_integrator = false, float airspeed_min = 0.0f, float airspeed_max = 0.0f, float airspeed = (0.0f / 0.0f));
+	float control_attitude(float roll_setpoint, float roll);
+
+	float control_bodyrate(float pitch,
+			float roll_rate, float yaw_rate,
+			float yaw_rate_setpoint,
+			float airspeed_min = 0.0f, float airspeed_max = 0.0f, float airspeed = (0.0f / 0.0f), float scaler = 1.0f, bool lock_integrator = false);
 
 	void reset_integrator();
 
@@ -66,18 +71,27 @@ public:
 			_tc = time_constant;
 		}
 	}
+
 	void set_k_p(float k_p) {
 		_k_p = k_p;
 	}
+
 	void set_k_i(float k_i) {
 		_k_i = k_i;
 	}
+
 	void set_k_d(float k_d) {
 		_k_d = k_d;
 	}
+
+	void set_k_ff(float k_ff) {
+		_k_ff = k_ff;
+	}
+
 	void set_integrator_max(float max) {
 		_integrator_max = max;
 	}
+
 	void set_max_rate(float max_rate) {
 		_max_rate = max_rate;
 	}
@@ -90,19 +104,24 @@ public:
 		return _rate_setpoint;
 	}
 
+	float get_desired_bodyrate() {
+		return _bodyrate_setpoint;
+	}
+
 private:
 	uint64_t _last_run;
 	float _tc;
 	float _k_p;
 	float _k_i;
 	float _k_d;
+	float _k_ff;
 	float _integrator_max;
 	float _max_rate;
 	float _last_output;
 	float _integrator;
 	float _rate_error;
 	float _rate_setpoint;
-	float _max_deflection_rad;
+	float _bodyrate_setpoint;
 };
 
 #endif // ECL_ROLL_CONTROLLER_H
diff --git a/src/lib/ecl/attitude_fw/ecl_yaw_controller.cpp b/src/lib/ecl/attitude_fw/ecl_yaw_controller.cpp
index b786acf24..7c366aaf2 100644
--- a/src/lib/ecl/attitude_fw/ecl_yaw_controller.cpp
+++ b/src/lib/ecl/attitude_fw/ecl_yaw_controller.cpp
@@ -44,29 +44,127 @@
 #include <geo/geo.h>
 #include <ecl/ecl.h>
 #include <mathlib/mathlib.h>
+#include <systemlib/err.h>
 
 ECL_YawController::ECL_YawController() :
 	_last_run(0),
-	_last_error(0.0f),
+	_k_p(0.0f),
+	_k_i(0.0f),
+	_k_d(0.0f),
+	_k_ff(0.0f),
+	_integrator_max(0.0f),
+	_max_rate(0.0f),
+	_roll_ff(0.0f),
 	_last_output(0.0f),
-	_last_rate_hp_out(0.0f),
-	_last_rate_hp_in(0.0f),
-	_k_d_last(0.0f),
-	_integrator(0.0f)
+	_integrator(0.0f),
+	_rate_error(0.0f),
+	_rate_setpoint(0.0f),
+	_bodyrate_setpoint(0.0f),
+	_coordinated_min_speed(1.0f)
 {
+}
+
+float ECL_YawController::control_attitude(float roll, float pitch,
+		float speed_body_u, float speed_body_v, float speed_body_w,
+		float roll_rate_setpoint, float pitch_rate_setpoint)
+{
+//	static int counter = 0;
+	/* Calculate desired yaw rate from coordinated turn constraint / (no side forces) */
+	_rate_setpoint = 0.0f;
+	if (sqrtf(speed_body_u * speed_body_u + speed_body_v * speed_body_v + speed_body_w * speed_body_w) > _coordinated_min_speed) {
+		float denumerator = (speed_body_u * cosf(roll) * cosf(pitch) + speed_body_w * sinf(pitch));
+		if(denumerator != 0.0f) { //XXX: floating point comparison
+			_rate_setpoint = (speed_body_w * roll_rate_setpoint + 9.81f * sinf(roll) * cosf(pitch) + speed_body_u * pitch_rate_setpoint * sinf(roll)) / denumerator;
+//			warnx("yaw: speed_body_u %.f speed_body_w %1.f roll %.1f pitch %.1f denumerator %.1f _rate_setpoint %.1f", speed_body_u, speed_body_w, denumerator, _rate_setpoint);
+		}
+
+//		if(counter % 20 == 0) {
+//			warnx("denumerator: %.4f, speed_body_u: %.4f, speed_body_w: %.4f, cosf(roll): %.4f, cosf(pitch): %.4f, sinf(pitch): %.4f", (double)denumerator, (double)speed_body_u, (double)speed_body_w, (double)cosf(roll), (double)cosf(pitch), (double)sinf(pitch));
+//		}
+	}
+
+	/* limit the rate */ //XXX: move to body angluar rates
+	if (_max_rate > 0.01f) {
+	_rate_setpoint = (_rate_setpoint > _max_rate) ? _max_rate : _rate_setpoint;
+	_rate_setpoint = (_rate_setpoint < -_max_rate) ? -_max_rate : _rate_setpoint;
+	}
+
 
+//	counter++;
+
+	if(!isfinite(_rate_setpoint)){
+		warnx("yaw rate sepoint not finite");
+		_rate_setpoint = 0.0f;
+	}
+
+	return _rate_setpoint;
 }
 
-float ECL_YawController::control(float roll, float yaw_rate, float accel_y, float scaler, bool lock_integrator,
-				 float airspeed_min, float airspeed_max, float aspeed)
+float ECL_YawController::control_bodyrate(float roll, float pitch,
+		float pitch_rate, float yaw_rate,
+		float pitch_rate_setpoint,
+		float airspeed_min, float airspeed_max, float airspeed, float scaler, bool lock_integrator)
 {
 	/* get the usual dt estimate */
 	uint64_t dt_micros = ecl_elapsed_time(&_last_run);
 	_last_run = ecl_absolute_time();
+	float dt = (float)dt_micros * 1e-6f;
+
+	/* lock integral for long intervals */
+	if (dt_micros > 500000)
+		lock_integrator = true;
+
+
+//	float k_ff = math::max((_k_p - _k_i * _tc) * _tc - _k_d, 0.0f);
+	float k_ff = 0;
+
+
+	/* input conditioning */
+	if (!isfinite(airspeed)) {
+	/* airspeed is NaN, +- INF or not available, pick center of band */
+	airspeed = 0.5f * (airspeed_min + airspeed_max);
+	} else if (airspeed < airspeed_min) {
+	airspeed = airspeed_min;
+	}
+
+
+	/* Transform setpoint to body angular rates */
+	_bodyrate_setpoint = -sinf(roll) * pitch_rate_setpoint + cosf(roll)*cosf(pitch) * _rate_setpoint; //jacobian
+
+	/* Transform estimation to body angular rates */
+	float yaw_bodyrate = -sinf(roll) * pitch_rate + cosf(roll)*cosf(pitch) * yaw_rate; //jacobian
+
+	/* Calculate body angular rate error */
+	_rate_error = _bodyrate_setpoint - yaw_bodyrate; //body angular rate error
+
+	if (!lock_integrator && _k_i > 0.0f && airspeed > 0.5f * airspeed_min) {
+
+	float id = _rate_error * dt;
+
+	/*
+	 * anti-windup: do not allow integrator to increase if actuator is at limit
+	 */
+	if (_last_output < -1.0f) {
+		/* only allow motion to center: increase value */
+		id = math::max(id, 0.0f);
+	} else if (_last_output > 1.0f) {
+		/* only allow motion to center: decrease value */
+		id = math::min(id, 0.0f);
+	}
+
+	_integrator += id;
+	}
+
+	/* integrator limit */
+	//xxx: until start detection is available: integral part in control signal is limited here
+	float integrator_constrained = math::constrain(_integrator * _k_i, -_integrator_max, _integrator_max);
+
+	/* Apply PI rate controller and store non-limited output */
+	_last_output = (_bodyrate_setpoint * _k_ff + _rate_error * _k_p + integrator_constrained + _rate_setpoint * k_ff) * scaler * scaler;  //scaler is proportional to 1/airspeed
+	//warnx("yaw:_last_output: %.4f, _integrator: %.4f, _integrator_max: %.4f, airspeed %.4f, _k_i %.4f, _k_p: %.4f", (double)_last_output, (double)_integrator, (double)_integrator_max, (double)airspeed, (double)_k_i, (double)_k_p);
 
-	float dt = (dt_micros > 500000) ? 0.0f : dt_micros / 1000000;
 
-	return 0.0f;
+	return math::constrain(_last_output, -1.0f, 1.0f);
 }
 
 void ECL_YawController::reset_integrator()
diff --git a/src/lib/ecl/attitude_fw/ecl_yaw_controller.h b/src/lib/ecl/attitude_fw/ecl_yaw_controller.h
index 66b227918..f15645fcf 100644
--- a/src/lib/ecl/attitude_fw/ecl_yaw_controller.h
+++ b/src/lib/ecl/attitude_fw/ecl_yaw_controller.h
@@ -35,6 +35,15 @@
  * @file ecl_yaw_controller.h
  * Definition of a simple orthogonal coordinated turn yaw PID controller.
  *
+ * @author Lorenz Meier <lm@inf.ethz.ch>
+ * @author Thomas Gubler <thomasgubler@gmail.com>
+ *
+ * Acknowledgements:
+ *
+ *   The control design is based on a design
+ *   by Paul Riseborough and Andrew Tridgell, 2013,
+ *   which in turn is based on initial work of
+ *   Jonathan Challinger, 2012.
  */
 #ifndef ECL_YAW_CONTROLLER_H
 #define ECL_YAW_CONTROLLER_H
@@ -42,47 +51,82 @@
 #include <stdbool.h>
 #include <stdint.h>
 
-class __EXPORT ECL_YawController
+class __EXPORT ECL_YawController //XXX: create controller superclass
 {
 public:
 	ECL_YawController();
 
-	float control(float roll, float yaw_rate, float accel_y, float scaler = 1.0f, bool lock_integrator = false,
-		      float airspeed_min = 0, float airspeed_max = 0, float aspeed = (0.0f / 0.0f));
+	float control_attitude(float roll, float pitch,
+			float speed_body_u, float speed_body_v, float speed_body_w,
+			float roll_rate_setpoint, float pitch_rate_setpoint);
+
+	float control_bodyrate(	float roll, float pitch,
+			float pitch_rate, float yaw_rate,
+			float pitch_rate_setpoint,
+			float airspeed_min, float airspeed_max, float airspeed, float scaler, bool lock_integrator);
 
 	void reset_integrator();
 
-	void set_k_side(float k_a) {
-		_k_side = k_a;
+	void set_k_p(float k_p) {
+			_k_p = k_p;
 	}
+
 	void set_k_i(float k_i) {
 		_k_i = k_i;
 	}
+
 	void set_k_d(float k_d) {
 		_k_d = k_d;
 	}
-	void set_k_roll_ff(float k_roll_ff) {
-		_k_roll_ff = k_roll_ff;
+
+	void set_k_ff(float k_ff) {
+		_k_ff = k_ff;
 	}
+
 	void set_integrator_max(float max) {
 		_integrator_max = max;
 	}
 
+	void set_max_rate(float max_rate) {
+		_max_rate = max_rate;
+	}
+
+	void set_k_roll_ff(float roll_ff) {
+		_roll_ff = roll_ff;
+	}
+
+	void set_coordinated_min_speed(float coordinated_min_speed) {
+		_coordinated_min_speed = coordinated_min_speed;
+	}
+
+
+	float get_rate_error() {
+		return _rate_error;
+	}
+
+	float get_desired_rate() {
+		return _rate_setpoint;
+	}
+
+	float get_desired_bodyrate() {
+		return _bodyrate_setpoint;
+	}
+
 private:
 	uint64_t _last_run;
-
-	float _k_side;
+	float _k_p;
 	float _k_i;
 	float _k_d;
-	float _k_roll_ff;
+	float _k_ff;
 	float _integrator_max;
-
-	float _last_error;
+	float _max_rate;
+	float  _roll_ff;
 	float _last_output;
-	float _last_rate_hp_out;
-	float _last_rate_hp_in;
-	float _k_d_last;
 	float _integrator;
+	float _rate_error;
+	float _rate_setpoint;
+	float _bodyrate_setpoint;
+	float _coordinated_min_speed;
 
 };
 
diff --git a/src/lib/ecl/l1/ecl_l1_pos_controller.cpp b/src/lib/ecl/l1/ecl_l1_pos_controller.cpp
index 27d76f959..31d7cecb7 100644
--- a/src/lib/ecl/l1/ecl_l1_pos_controller.cpp
+++ b/src/lib/ecl/l1/ecl_l1_pos_controller.cpp
@@ -70,7 +70,7 @@ float ECL_L1_Pos_Controller::target_bearing()
 float ECL_L1_Pos_Controller::switch_distance(float wp_radius)
 {
 	/* following [2], switching on L1 distance */
-	return math::max(wp_radius, _L1_distance);
+	return math::min(wp_radius, _L1_distance);
 }
 
 bool ECL_L1_Pos_Controller::reached_loiter_target(void)
diff --git a/src/lib/external_lgpl/tecs/tecs.cpp b/src/lib/external_lgpl/tecs/tecs.cpp
index 864a9d24d..510b8ed9c 100644
--- a/src/lib/external_lgpl/tecs/tecs.cpp
+++ b/src/lib/external_lgpl/tecs/tecs.cpp
@@ -2,6 +2,7 @@
 
 #include "tecs.h"
 #include <ecl/ecl.h>
+#include <systemlib/err.h>
 
 using namespace math;
 
@@ -199,33 +200,47 @@ void TECS::_update_speed_demand(void)
 	_TAS_dem_last = _TAS_dem;
 }
 
-void TECS::_update_height_demand(float demand)
+void TECS::_update_height_demand(float demand, float state)
 {
-	// Apply 2 point moving average to demanded height
-	// This is required because height demand is only updated at 5Hz
-	_hgt_dem = 0.5f * (demand + _hgt_dem_in_old);
-	_hgt_dem_in_old = _hgt_dem;
-
-	// printf("hgt_dem: %6.2f hgt_dem_last: %6.2f max_climb_rate: %6.2f\n", _hgt_dem, _hgt_dem_prev,
-	// 	_maxClimbRate);
+//	// Apply 2 point moving average to demanded height
+//	// This is required because height demand is only updated at 5Hz
+//	_hgt_dem = 0.5f * (demand + _hgt_dem_in_old);
+//	_hgt_dem_in_old = _hgt_dem;
+//
+//	// printf("hgt_dem: %6.2f hgt_dem_last: %6.2f max_climb_rate: %6.2f\n", _hgt_dem, _hgt_dem_prev,
+//	// 	_maxClimbRate);
+//
+//	// Limit height rate of change
+//	if ((_hgt_dem - _hgt_dem_prev) > (_maxClimbRate * 0.1f)) {
+//		_hgt_dem = _hgt_dem_prev + _maxClimbRate * 0.1f;
+//
+//	} else if ((_hgt_dem - _hgt_dem_prev) < (-_maxSinkRate * 0.1f)) {
+//		_hgt_dem = _hgt_dem_prev - _maxSinkRate * 0.1f;
+//	}
+//
+//	_hgt_dem_prev = _hgt_dem;
+//
+//	// Apply first order lag to height demand
+//	_hgt_dem_adj = 0.05f * _hgt_dem + 0.95f * _hgt_dem_adj_last;
+//	_hgt_rate_dem = (_hgt_dem_adj - _hgt_dem_adj_last) / 0.1f;
+//	_hgt_dem_adj_last = _hgt_dem_adj;
+//
+//	// printf("hgt_dem: %6.2f hgt_dem_adj: %6.2f hgt_dem_last: %6.2f hgt_rate_dem: %6.2f\n", _hgt_dem, _hgt_dem_adj, _hgt_dem_adj_last,
+//	// 	_hgt_rate_dem);
+
+	_hgt_dem_adj = demand;//0.025f * demand + 0.975f * _hgt_dem_adj_last;
+	_hgt_dem_adj_last = _hgt_dem_adj;
 
+	_hgt_rate_dem = (_hgt_dem_adj-state)*_heightrate_p;
 	// Limit height rate of change
-	if ((_hgt_dem - _hgt_dem_prev) > (_maxClimbRate * 0.1f)) {
-		_hgt_dem = _hgt_dem_prev + _maxClimbRate * 0.1f;
+	if (_hgt_rate_dem > _maxClimbRate) {
+		_hgt_rate_dem = _maxClimbRate;
 
-	} else if ((_hgt_dem - _hgt_dem_prev) < (-_maxSinkRate * 0.1f)) {
-		_hgt_dem = _hgt_dem_prev - _maxSinkRate * 0.1f;
+	} else if (_hgt_rate_dem < -_maxSinkRate) {
+		_hgt_rate_dem = -_maxSinkRate;
 	}
 
-	_hgt_dem_prev = _hgt_dem;
-
-	// Apply first order lag to height demand
-	_hgt_dem_adj = 0.05f * _hgt_dem + 0.95f * _hgt_dem_adj_last;
-	_hgt_rate_dem = (_hgt_dem_adj - _hgt_dem_adj_last) / 0.1f;
-	_hgt_dem_adj_last = _hgt_dem_adj;
-
-	// printf("hgt_dem: %6.2f hgt_dem_adj: %6.2f hgt_dem_last: %6.2f hgt_rate_dem: %6.2f\n", _hgt_dem, _hgt_dem_adj, _hgt_dem_adj_last,
-	// 	_hgt_rate_dem);
+	warnx("_hgt_rate_dem: %.4f, _hgt_dem_adj %.4f", _hgt_rate_dem, _hgt_dem_adj);
 }
 
 void TECS::_detect_underspeed(void)
@@ -299,7 +314,7 @@ void TECS::_update_throttle(float throttle_cruise, const math::Dcm &rotMat)
 
 		// Rate limit PD + FF throttle
 		// Calculate the throttle increment from the specified slew time
-		if (fabsf(_throttle_slewrate) < 0.01f) {
+		if (fabsf(_throttle_slewrate) > 0.01f) {
 			float thrRateIncr = _DT * (_THRmaxf - _THRminf) * _throttle_slewrate;
 
 			_throttle_dem = constrain(_throttle_dem,
@@ -500,7 +515,7 @@ void TECS::update_pitch_throttle(const math::Dcm &rotMat, float pitch, float bar
 	_update_speed_demand();
 
 	// Calculate the height demand
-	_update_height_demand(hgt_dem);
+	_update_height_demand(hgt_dem, baro_altitude);
 
 	// Detect underspeed condition
 	_detect_underspeed();
diff --git a/src/lib/external_lgpl/tecs/tecs.h b/src/lib/external_lgpl/tecs/tecs.h
index f8f832ed7..06e1c8ad3 100644
--- a/src/lib/external_lgpl/tecs/tecs.h
+++ b/src/lib/external_lgpl/tecs/tecs.h
@@ -180,6 +180,10 @@ public:
 		_indicated_airspeed_max = airspeed;
 	}
 
+	void set_heightrate_p(float heightrate_p) {
+		_heightrate_p = heightrate_p;
+	}
+
 private:
 	// Last time update_50Hz was called
 	uint64_t _update_50hz_last_usec;
@@ -203,6 +207,7 @@ private:
 	float _vertAccLim;
 	float _rollComp;
 	float _spdWeight;
+	float _heightrate_p;
 
 	// throttle demand in the range from 0.0 to 1.0
 	float _throttle_dem;
@@ -329,7 +334,7 @@ private:
 	void _update_speed_demand(void);
 
 	// Update the demanded height
-	void _update_height_demand(float demand);
+	void _update_height_demand(float demand, float state);
 
 	// Detect an underspeed condition
 	void _detect_underspeed(void);