/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- /* * control_flip.pde - init and run calls for flip flight mode * original implementation in 2010 by Jose Julio * Adapted and updated for AC2 in 2011 by Jason Short * * Controls: * CH7_OPT or CH8_OPT parameter must be set to "Flip" (AUX_SWITCH_FLIP) which is "2" * Pilot switches to Stabilize, Acro or AltHold flight mode and puts ch7/ch8 switch to ON position * Vehicle will Roll right by default but if roll or pitch stick is held slightly left, forward or back it will flip in that direction * Vehicle should complete the roll within 2.5sec and will then return to the original flight mode it was in before flip was triggered * Pilot may manually exit flip by switching off ch7/ch8 or by moving roll stick to >40deg left or right * * State machine approach: * Flip_Start (while copter is leaning <45deg) : roll right at 400deg/sec, increase throttle * Flip_Roll (while copter is between +45deg ~ -90) : roll right at 400deg/sec, reduce throttle * Flip_Recover (while copter is between -90deg and original target angle) : use earth frame angle controller to return vehicle to original attitude */ #define FLIP_THR_INC 200 // throttle increase during Flip_Start stage (under 45deg lean angle) #define FLIP_THR_DEC 240 // throttle decrease during Flip_Roll stage (between 45deg ~ -90deg roll) #define FLIP_ROTATION_RATE 40000 // rotation rate request in centi-degrees / sec (i.e. 400 deg/sec) #define FLIP_TIMEOUT_MS 2500 // timeout after 2.5sec. Vehicle will switch back to original flight mode #define FLIP_RECOVERY_ANGLE 500 // consider successful recovery when roll is back within 5 degrees of original #define FLIP_ROLL_RIGHT 1 // used to set flip_dir #define FLIP_ROLL_LEFT -1 // used to set flip_dir #define FLIP_PITCH_BACK 1 // used to set flip_dir #define FLIP_PITCH_FORWARD -1 // used to set flip_dir FlipState flip_state; // current state of flip uint8_t flip_orig_control_mode; // flight mode when flip was initated uint32_t flip_start_time; // time since flip began int8_t flip_roll_dir; // roll direction (-1 = roll left, 1 = roll right) int8_t flip_pitch_dir; // pitch direction (-1 = pitch forward, 1 = pitch back) // flip_init - initialise flip controller static bool flip_init(bool ignore_checks) { // only allow flip from ACRO, Stabilize, AltHold or Drift flight modes if (control_mode != ACRO && control_mode != STABILIZE && control_mode != ALT_HOLD) { return false; } // if in acro or stabilize ensure throttle is above zero if ((g.rc_3.control_in <= 0) && (control_mode == ACRO || control_mode == STABILIZE)) { return false; } // ensure roll input is less than 40deg if (abs(g.rc_1.control_in) >= 4000) { return false; } // only allow flip when flying if (!motors.armed() || ap.land_complete) { return false; } // capture original flight mode so that we can return to it after completion flip_orig_control_mode = control_mode; // initialise state flip_state = Flip_Start; flip_start_time = millis(); flip_roll_dir = flip_pitch_dir = 0; // choose direction based on pilot's roll and pitch sticks if (g.rc_2.control_in > 300) { flip_pitch_dir = FLIP_PITCH_BACK; }else if(g.rc_2.control_in < -300) { flip_pitch_dir = FLIP_PITCH_FORWARD; }else if (g.rc_1.control_in >= 0) { flip_roll_dir = FLIP_ROLL_RIGHT; }else{ flip_roll_dir = FLIP_ROLL_LEFT; } // log start of flip Log_Write_Event(DATA_FLIP_START); // capture current attitude which will be used during the Flip_Recovery stage flip_orig_attitude.x = constrain_float(ahrs.roll_sensor, -aparm.angle_max, aparm.angle_max); flip_orig_attitude.y = constrain_float(ahrs.pitch_sensor, -aparm.angle_max, aparm.angle_max); flip_orig_attitude.z = ahrs.yaw_sensor; return true; } // flip_run - runs the flip controller // should be called at 100hz or more static void flip_run() { int16_t throttle_out; float recovery_angle; // if pilot inputs roll > 40deg or timeout occurs abandon flip if (!motors.armed() || (abs(g.rc_1.control_in) >= 4000) || (abs(g.rc_2.control_in) >= 4000) || ((millis() - flip_start_time) > FLIP_TIMEOUT_MS)) { flip_state = Flip_Abandon; } // get pilot's desired throttle throttle_out = get_pilot_desired_throttle(g.rc_3.control_in); // get corrected angle based on direction and axis of rotation // we flip the sign of flip_angle to minimize the code repetition int32_t flip_angle; if (flip_roll_dir != 0) { flip_angle = ahrs.roll_sensor * flip_roll_dir; } else { flip_angle = ahrs.pitch_sensor * flip_pitch_dir; } // state machine switch (flip_state) { case Flip_Start: // under 45 degrees request 400deg/sec roll or pitch attitude_control.rate_bf_roll_pitch_yaw(FLIP_ROTATION_RATE * flip_roll_dir, FLIP_ROTATION_RATE * flip_pitch_dir, 0.0); // increase throttle throttle_out += FLIP_THR_INC; // beyond 45deg lean angle move to next stage if (flip_angle >= 4500) { if (flip_roll_dir != 0) { // we are rolling flip_state = Flip_Roll; } else { // we are pitching flip_state = Flip_Pitch_A; } } break; case Flip_Roll: // between 45deg ~ -90deg request 400deg/sec roll attitude_control.rate_bf_roll_pitch_yaw(FLIP_ROTATION_RATE * flip_roll_dir, 0.0, 0.0); // decrease throttle if (throttle_out >= g.throttle_min) { throttle_out = max(throttle_out - FLIP_THR_DEC, g.throttle_min); } // beyond -90deg move on to recovery if ((flip_angle < 4500) && (flip_angle > -9000)) { flip_state = Flip_Recover; } break; case Flip_Pitch_A: // between 45deg ~ -90deg request 400deg/sec pitch attitude_control.rate_bf_roll_pitch_yaw(0.0, FLIP_ROTATION_RATE * flip_pitch_dir, 0.0); // decrease throttle if (throttle_out >= g.throttle_min) { throttle_out = max(throttle_out - FLIP_THR_DEC, g.throttle_min); } // check roll for inversion if ((labs(ahrs.roll_sensor) > 9000) && (flip_angle > 4500)) { flip_state = Flip_Pitch_B; } break; case Flip_Pitch_B: // between 45deg ~ -90deg request 400deg/sec pitch attitude_control.rate_bf_roll_pitch_yaw(0.0, FLIP_ROTATION_RATE * flip_pitch_dir, 0.0); // decrease throttle if (throttle_out >= g.throttle_min) { throttle_out = max(throttle_out - FLIP_THR_DEC, g.throttle_min); } // check roll for inversion if ((labs(ahrs.roll_sensor) < 9000) && (flip_angle > -4500)) { flip_state = Flip_Recover; } break; case Flip_Recover: // use originally captured earth-frame angle targets to recover attitude_control.angle_ef_roll_pitch_yaw(flip_orig_attitude.x, flip_orig_attitude.y, flip_orig_attitude.z, false); // increase throttle to gain any lost altitude throttle_out += FLIP_THR_INC; if (flip_roll_dir != 0) { // we are rolling recovery_angle = fabs(flip_orig_attitude.x - (float)ahrs.roll_sensor); } else { // we are pitching recovery_angle = fabs(flip_orig_attitude.y - (float)ahrs.pitch_sensor); } // check for successful recovery if (fabs(recovery_angle) <= FLIP_RECOVERY_ANGLE) { // restore original flight mode if (!set_mode(flip_orig_control_mode)) { // this should never happen but just in case set_mode(STABILIZE); } // log successful completion Log_Write_Event(DATA_FLIP_END); } break; case Flip_Abandon: // restore original flight mode if (!set_mode(flip_orig_control_mode)) { // this should never happen but just in case set_mode(STABILIZE); } // log abandoning flip Log_Write_Error(ERROR_SUBSYSTEM_FLIP,ERROR_CODE_FLIP_ABANDONED); break; } // output pilot's throttle without angle boost attitude_control.set_throttle_out(throttle_out, false); }