// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- //**************************************************************** // Function that will calculate the desired direction to fly and distance //**************************************************************** static void navigate() { // waypoint distance from plane in cm // --------------------------------------- wp_distance = get_distance_cm(&filtered_loc, &next_WP); home_distance = get_distance_cm(&filtered_loc, &home); // target_bearing is where we should be heading // -------------------------------------------- target_bearing = get_bearing_cd(&filtered_loc, &next_WP); home_to_copter_bearing = get_bearing_cd(&home, ¤t_loc); } static bool check_missed_wp() { int32_t temp; temp = target_bearing - original_target_bearing; temp = wrap_180(temp); return (labs(temp) > 9000); // we passed the waypoint by 100 degrees } // ------------------------------ static void calc_XY_velocity(){ static int32_t last_longitude = 0; static int32_t last_latitude = 0; // called after GPS read // offset calculation of GPS speed: // used for estimations below 1.5m/s // y_GPS_speed positve = Up // x_GPS_speed positve = Right // initialise last_longitude and last_latitude if( last_longitude == 0 && last_latitude == 0 ) { last_longitude = g_gps->longitude; last_latitude = g_gps->latitude; } // this speed is ~ in cm because we are using 10^7 numbers from GPS float tmp = 1.0/dTnav; x_actual_speed = (float)(g_gps->longitude - last_longitude) * scaleLongDown * tmp; y_actual_speed = (float)(g_gps->latitude - last_latitude) * tmp; last_longitude = g_gps->longitude; last_latitude = g_gps->latitude; #if INERTIAL_NAV == ENABLED // inertial_nav xy_error_correction(); filtered_loc.lng = xLeadFilter.get_position(g_gps->longitude, accels_velocity.x); filtered_loc.lat = yLeadFilter.get_position(g_gps->latitude, accels_velocity.y); #else filtered_loc.lng = xLeadFilter.get_position(g_gps->longitude, x_actual_speed, g_gps->get_lag()); filtered_loc.lat = yLeadFilter.get_position(g_gps->latitude, y_actual_speed, g_gps->get_lag()); #endif } static void calc_location_error(struct Location *next_loc) { /* * Becuase we are using lat and lon to do our distance errors here's a quick chart: * 100 = 1m * 1000 = 11m = 36 feet * 1800 = 19.80m = 60 feet * 3000 = 33m * 10000 = 111m */ // X Error long_error = (float)(next_loc->lng - current_loc.lng) * scaleLongDown; // 500 - 0 = 500 Go East // Y Error lat_error = next_loc->lat - current_loc.lat; // 500 - 0 = 500 Go North } #define NAV_ERR_MAX 600 #define NAV_RATE_ERR_MAX 250 static void calc_loiter(int16_t x_error, int16_t y_error) { int32_t p,i,d; // used to capture pid values for logging int32_t output; int32_t x_target_speed, y_target_speed; // East / West x_target_speed = g.pi_loiter_lon.get_p(x_error); // calculate desired speed from lon error #if LOGGING_ENABLED == ENABLED // log output if PID logging is on and we are tuning the yaw if( g.log_bitmask & MASK_LOG_PID && (g.radio_tuning == CH6_LOITER_KP || g.radio_tuning == CH6_LOITER_KI) ) { Log_Write_PID(CH6_LOITER_KP, x_error, x_target_speed, 0, 0, x_target_speed, tuning_value); } #endif // calculate rate error #if INERTIAL_NAV == ENABLED x_rate_error = x_target_speed - accels_velocity.x; // calc the speed error #else x_rate_error = x_target_speed - x_actual_speed; // calc the speed error #endif p = g.pid_loiter_rate_lon.get_p(x_rate_error); i = g.pid_loiter_rate_lon.get_i(x_rate_error + x_error, dTnav); d = g.pid_loiter_rate_lon.get_d(x_error, dTnav); d = constrain(d, -2000, 2000); // get rid of noise if(abs(x_actual_speed) < 50) { d = 0; } output = p + i + d; nav_lon = constrain(output, -32000, 32000); // constraint to remove chance of overflow when adding int32_t to int16_t #if LOGGING_ENABLED == ENABLED // log output if PID logging is on and we are tuning the yaw if( g.log_bitmask & MASK_LOG_PID && (g.radio_tuning == CH6_LOITER_RATE_KP || g.radio_tuning == CH6_LOITER_RATE_KI || g.radio_tuning == CH6_LOITER_RATE_KD) ) { Log_Write_PID(CH6_LOITER_RATE_KP, x_rate_error, p, i, d, nav_lon, tuning_value); } #endif // North / South y_target_speed = g.pi_loiter_lat.get_p(y_error); // calculate desired speed from lat error #if LOGGING_ENABLED == ENABLED // log output if PID logging is on and we are tuning the yaw if( g.log_bitmask & MASK_LOG_PID && (g.radio_tuning == CH6_LOITER_KP || g.radio_tuning == CH6_LOITER_KI) ) { Log_Write_PID(CH6_LOITER_KP+100, y_error, y_target_speed, 0, 0, y_target_speed, tuning_value); } #endif // calculate rate error #if INERTIAL_NAV == ENABLED y_rate_error = y_target_speed - accels_velocity.y; // calc the speed error #else y_rate_error = y_target_speed - y_actual_speed; // calc the speed error #endif p = g.pid_loiter_rate_lat.get_p(y_rate_error); i = g.pid_loiter_rate_lat.get_i(y_rate_error + y_error, dTnav); d = g.pid_loiter_rate_lat.get_d(y_error, dTnav); d = constrain(d, -2000, 2000); // get rid of noise if(abs(y_actual_speed) < 50) { d = 0; } output = p + i + d; nav_lat = constrain(output, -32000, 32000); // constraint to remove chance of overflow when adding int32_t to int16_t #if LOGGING_ENABLED == ENABLED // log output if PID logging is on and we are tuning the yaw if( g.log_bitmask & MASK_LOG_PID && (g.radio_tuning == CH6_LOITER_RATE_KP || g.radio_tuning == CH6_LOITER_RATE_KI || g.radio_tuning == CH6_LOITER_RATE_KD) ) { Log_Write_PID(CH6_LOITER_RATE_KP+100, y_rate_error, p, i, d, nav_lat, tuning_value); } #endif // copy over I term to Nav_Rate g.pid_nav_lon.set_integrator(g.pid_loiter_rate_lon.get_integrator()); g.pid_nav_lat.set_integrator(g.pid_loiter_rate_lat.get_integrator()); } static void calc_nav_rate(int16_t max_speed) { float temp, temp_x, temp_y; // push us towards the original track update_crosstrack(); int16_t cross_speed = crosstrack_error * -g.crosstrack_gain; // scale down crosstrack_error in cm cross_speed = constrain(cross_speed, -150, 150); // rotate by 90 to deal with trig functions temp = (9000l - target_bearing) * RADX100; temp_x = cos(temp); temp_y = sin(temp); // rotate desired spped vector: int32_t x_target_speed = max_speed * temp_x - cross_speed * temp_y; int32_t y_target_speed = cross_speed * temp_x + max_speed * temp_y; // East / West // calculate rate error #if INERTIAL_NAV == ENABLED x_rate_error = x_target_speed - accels_velocity.x; #else x_rate_error = x_target_speed - x_actual_speed; #endif x_rate_error = constrain(x_rate_error, -500, 500); nav_lon = g.pid_nav_lon.get_pid(x_rate_error, dTnav); int32_t tilt = (x_target_speed * x_target_speed * (int32_t)g.tilt_comp) / 10000; if(x_target_speed < 0) tilt = -tilt; nav_lon += tilt; // North / South // calculate rate error #if INERTIAL_NAV == ENABLED y_rate_error = y_target_speed - accels_velocity.y; #else y_rate_error = y_target_speed - y_actual_speed; #endif y_rate_error = constrain(y_rate_error, -500, 500); // added a rate error limit to keep pitching down to a minimum nav_lat = g.pid_nav_lat.get_pid(y_rate_error, dTnav); tilt = (y_target_speed * y_target_speed * (int32_t)g.tilt_comp) / 10000; if(y_target_speed < 0) tilt = -tilt; nav_lat += tilt; // copy over I term to Loiter_Rate g.pid_loiter_rate_lon.set_integrator(g.pid_nav_lon.get_integrator()); g.pid_loiter_rate_lat.set_integrator(g.pid_nav_lat.get_integrator()); } // this calculation rotates our World frame of reference to the copter's frame of reference // We use the DCM's matrix to precalculate these trig values at 50hz static void calc_loiter_pitch_roll() { //Serial.printf("ys %ld, cx %1.4f, _cx %1.4f | sy %1.4f, _sy %1.4f\n", dcm.yaw_sensor, cos_yaw_x, _cos_yaw_x, sin_yaw_y, _sin_yaw_y); // rotate the vector auto_roll = (float)nav_lon * sin_yaw_y - (float)nav_lat * cos_yaw_x; auto_pitch = (float)nav_lon * cos_yaw_x + (float)nav_lat * sin_yaw_y; // flip pitch because forward is negative auto_pitch = -auto_pitch; } static int16_t get_desired_speed(int16_t max_speed) { /* Based on Equation by Bill Premerlani & Robert Lefebvre (sq(V2)-sq(V1))/2 = A(X2-X1) derives to: V1 = sqrt(sq(V2) - 2*A*(X2-X1)) */ if(fast_corner) { // don't slow down }else{ if(wp_distance < 20000){ // limit the size of numbers we're dealing with to avoide overflow // go slower int32_t temp = 2 * 100 * (int32_t)(wp_distance - g.waypoint_radius * 100); int32_t s_min = WAYPOINT_SPEED_MIN; temp += s_min * s_min; max_speed = sqrt((float)temp); max_speed = min(max_speed, g.waypoint_speed_max); } } max_speed = min(max_speed, max_speed_old + (100 * dTnav));// limit going faster max_speed = max(max_speed, WAYPOINT_SPEED_MIN); // don't go too slow max_speed_old = max_speed; return max_speed; } static void reset_desired_speed() { max_speed_old = 0; } static int16_t get_desired_climb_rate() { if(alt_change_flag == ASCENDING) { return constrain(altitude_error / 4, 100, 180); // 180cm /s up, minimum is 100cm/s }else if(alt_change_flag == DESCENDING) { return constrain(altitude_error / 6, -100, -10); // -100cm /s down, max is -10cms }else{ return 0; } } static void update_crosstrack(void) { // Crosstrack Error // ---------------- // If we are too far off or too close we don't do track following float temp = (target_bearing - original_target_bearing) * RADX100; crosstrack_error = sin(temp) * wp_distance; // Meters we are off track line } static int32_t get_altitude_error() { // Next_WP alt is our target alt // It changes based on climb rate // until it reaches the target_altitude return next_WP.alt - current_loc.alt; } static void clear_new_altitude() { alt_change_flag = REACHED_ALT; } static void force_new_altitude(int32_t new_alt) { next_WP.alt = new_alt; alt_change_flag = REACHED_ALT; } static void set_new_altitude(int32_t new_alt) { next_WP.alt = new_alt; if(next_WP.alt > current_loc.alt + 20) { // we are below, going up alt_change_flag = ASCENDING; }else if(next_WP.alt < current_loc.alt - 20) { // we are above, going down alt_change_flag = DESCENDING; }else{ // No Change alt_change_flag = REACHED_ALT; } } static void verify_altitude() { if(alt_change_flag == ASCENDING) { // we are below, going up if(current_loc.alt > next_WP.alt - 50) { alt_change_flag = REACHED_ALT; } }else if (alt_change_flag == DESCENDING) { // we are above, going down if(current_loc.alt <= next_WP.alt + 50) alt_change_flag = REACHED_ALT; } } static int32_t wrap_360(int32_t error) { if (error > 36000) error -= 36000; if (error < 0) error += 36000; return error; } static int32_t wrap_180(int32_t error) { if (error > 18000) error -= 36000; if (error < -18000) error += 36000; return error; }