fw control: work in progress, heading rate control loop

1 files changed, 35 insertions, 11 deletions

diff --git a/apps/fixedwing_pos_control/fixedwing_pos_control_main.c b/apps/fixedwing_pos_control/fixedwing_pos_control_main.c
index 4a1025109..8fc272eb6 100644
--- a/apps/fixedwing_pos_control/fixedwing_pos_control_main.c
+++ b/apps/fixedwing_pos_control/fixedwing_pos_control_main.c
@@ -75,6 +75,8 @@ PARAM_DEFINE_FLOAT(FW_PITCH_LIM, 0.35f);	// Pitch angle limit in radians
 
 struct fw_pos_control_params {
 	float heading_p;
+	float headingr_p;
+	float headingr_i;
 	float xtrack_p;
 	float altitude_p;
 	float roll_lim;
@@ -83,6 +85,8 @@ struct fw_pos_control_params {
 
 struct fw_pos_control_param_handles {
 	param_t heading_p;
+	param_t headingr_p;
+	param_t headingr_i;
 	param_t xtrack_p;
 	param_t altitude_p;
 	param_t roll_lim;
@@ -124,6 +128,8 @@ static int parameters_init(struct fw_pos_control_param_handles *h)
 {
 	/* PID parameters */
 	h->heading_p 	=	param_find("FW_HEADING_P");
+	h->headingr_p 	=	param_find("FW_HEADINGR_P");
+	h->headingr_i 	=	param_find("FW_HEADINGR_I");
 	h->xtrack_p 	=	param_find("FW_XTRACK_P");
 	h->altitude_p 	=	param_find("FW_ALT_P");
 	h->roll_lim 	=	param_find("FW_ROLL_LIM");
@@ -136,6 +142,8 @@ static int parameters_init(struct fw_pos_control_param_handles *h)
 static int parameters_update(const struct fw_pos_control_param_handles *h, struct fw_pos_control_params *p)
 {
 	param_get(h->heading_p, &(p->heading_p));
+	param_get(h->headingr_p, &(p->headingr_p));
+	param_get(h->headingr_i, &(p->headingr_i));
 	param_get(h->xtrack_p, &(p->xtrack_p));
 	param_get(h->altitude_p, &(p->altitude_p));
 	param_get(h->roll_lim, &(p->roll_lim));
@@ -205,14 +213,22 @@ int fixedwing_pos_control_thread_main(int argc, char *argv[])
 			static struct fw_pos_control_param_handles h;
 
 			PID_t heading_controller;
+			PID_t heading_rate_controller;
+			PID_t offtrack_controller;
 			PID_t altitude_controller;
 
+			static uint64_t last_run = 0;
+			const float deltaT = (hrt_absolute_time() - last_run) / 1000000.0f;
+			last_run = hrt_absolute_time();
+
 			if(!initialized)
 			{
 				parameters_init(&h);
 				parameters_update(&h, &p);
-				pid_init(&heading_controller, p.heading_p, 0.0f, 0.0f, 0.0f,p.roll_lim,PID_MODE_DERIVATIV_NONE);
-				pid_init(&altitude_controller, p.altitude_p, 0.0f, 0.0f, 0.0f,p.pitch_lim,PID_MODE_DERIVATIV_NONE);
+				pid_init(&heading_controller, p.heading_p, 0.0f, 0.0f, 0.0f, 10000.0f, PID_MODE_DERIVATIV_NONE); //arbitrary high limit
+				pid_init(&heading_rate_controller, p.headingr_p, p.headingr_i, 0.0f, 0.0f, p.roll_lim, PID_MODE_DERIVATIV_NONE);
+				pid_init(&altitude_controller, p.altitude_p, 0.0f, 0.0f, 0.0f, p.pitch_lim, PID_MODE_DERIVATIV_NONE);
+				pid_init(&offtrack_controller, p.xtrack_p, 0.0f, 0.0f, 0.0f , 60.0f*M_DEG_TO_RAD, PID_MODE_DERIVATIV_NONE); //TODO: remove hardcoded value
 				initialized = true;
 			}
 
@@ -220,8 +236,10 @@ int fixedwing_pos_control_thread_main(int argc, char *argv[])
 			if (counter % 100 == 0) {
 				/* update parameters from storage */
 				parameters_update(&h, &p);
-				pid_set_parameters(&heading_controller, p.heading_p, 0, 0, 0, p.roll_lim);
+				pid_set_parameters(&heading_controller, p.heading_p, 0, 0, 0, 10000.0f); //arbitrary high limit
+				pid_set_parameters(&heading_rate_controller, p.headingr_p, p.headingr_i, 0, 0, p.roll_lim);
 				pid_set_parameters(&altitude_controller, p.altitude_p, 0, 0, 0, p.pitch_lim);
+				pid_set_parameters(&offtrack_controller, p.xtrack_p, 0, 0, 0, 60.0f*M_DEG_TO_RAD); //TODO: remove hardcoded value
 
 			}
 
@@ -262,13 +280,7 @@ int fixedwing_pos_control_thread_main(int argc, char *argv[])
 
 				if(!(distance_res != OK || xtrack_err.past_end)) {
 
-					float delta_psi_c = -p.xtrack_p * xtrack_err.distance; //(-) because z axis points downwards
-
-					if(delta_psi_c > 60.0f*M_DEG_TO_RAD)
-						delta_psi_c = 60.0f*M_DEG_TO_RAD;
-
-					if(delta_psi_c < -60.0f*M_DEG_TO_RAD)
-						delta_psi_c = -60.0f*M_DEG_TO_RAD;
+					float delta_psi_c = -pid_calculate(&offtrack_controller, 0, xtrack_err.distance, 0.0f, 0.0f); //p.xtrack_p * xtrack_err.distance; //(-) because z axis points downwards
 
 					float psi_c = psi_track + delta_psi_c;
 
@@ -278,7 +290,19 @@ int fixedwing_pos_control_thread_main(int argc, char *argv[])
 					psi_e = _wrapPI(psi_e);
 
 					/* calculate roll setpoint, do this artificially around zero */
-					attitude_setpoint.roll_tait_bryan = pid_calculate(&heading_controller, psi_e, 0.0f, 0.0f, 0.0f);
+					//TODO: psi rate loop incomplete
+					float delta_psi_rate_c = pid_calculate(&heading_controller, psi_e, 0.0f, 0.0f, 0.0f);
+					float psi_rate_track = 0; //=V_gr/r_track , this will be needed for implementation of arc following
+					float psi_rate_c = delta_psi_rate_c + psi_rate_track;
+
+					//TODO limit turn rate
+
+					float psi_rate_e = psi_rate_c - att.yawspeed;
+
+					float psi_rate_e_scaled = psi_rate_e * sqrtf(pow(global_pos.vx,2) + pow(global_pos.vy,2)) / 9.81f; //* V_gr / g
+
+					attitude_setpoint.roll_tait_bryan = pid_calculate(&heading_rate_controller, psi_rate_e_scaled, 0.0f, 0.0f, deltaT);
+
 
 //					if (counter % 100 == 0)
 //						printf("xtrack_err.distance: %0.4f, delta_psi_c: %0.4f\n",xtrack_err.distance, delta_psi_c);