mirror of https://github.com/ArduPilot/ardupilot
102 lines
4.5 KiB
Plaintext
102 lines
4.5 KiB
Plaintext
/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
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// counter to verify landings
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static uint32_t land_detector = ((float)LAND_DETECTOR_TRIGGER_SEC)*MAIN_LOOP_RATE; // we assume we are landed
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// land_complete_maybe - return true if we may have landed (used to reset loiter targets during landing)
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static bool land_complete_maybe()
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{
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return (ap.land_complete || ap.land_complete_maybe);
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}
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// update_land_detector - checks if we have landed and updates the ap.land_complete flag
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// called at MAIN_LOOP_RATE
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static void update_land_detector()
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{
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// land detector can not use the following sensors because they are unreliable during landing
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// barometer altitude : ground effect can cause errors larger than 4m
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// EKF vertical velocity or altitude : poor barometer and large acceleration from ground impact
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// earth frame angle or angle error : landing on an uneven surface will force the airframe to match the ground angle
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// gyro output : on uneven surface the airframe may rock back an forth after landing
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// range finder : tend to be problematic at very short distances
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// input throttle : in slow land the input throttle may be only slightly less than hover
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#if FRAME_CONFIG == HELI_FRAME
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// check that collective pitch is on lower limit (should be constrained by LAND_COL_MIN)
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bool motor_at_lower_limit = motors.limit.throttle_lower;
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#else
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// check that the average throttle output is near minimum (less than 12.5% hover throttle)
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bool motor_at_lower_limit = motors.limit.throttle_lower && motors.is_throttle_mix_min();
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#endif
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Vector3f accel_ef = ahrs.get_accel_ef_blended();
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accel_ef.z += GRAVITY_MSS;
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// lowpass filter on accel
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accel_ef = land_accel_ef_filter.apply(accel_ef, MAIN_LOOP_SECONDS);
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// check that the airframe is not accelerating (not falling or breaking after fast forward flight)
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bool accel_stationary = (accel_ef.length() < 1.0f);
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if ( motor_at_lower_limit && accel_stationary) {
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if (!ap.land_complete) {
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// increase counter until we hit the trigger then set land complete flag
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if( land_detector < ((float)LAND_DETECTOR_TRIGGER_SEC)*MAIN_LOOP_RATE) {
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land_detector++;
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}else{
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set_land_complete(true);
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land_detector = ((float)LAND_DETECTOR_TRIGGER_SEC)*MAIN_LOOP_RATE;
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}
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}
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} else {
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// we've sensed movement up or down so reset land_detector
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land_detector = 0;
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// if throttle output is high then clear landing flag
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if (motors.get_throttle() > get_non_takeoff_throttle()) {
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set_land_complete(false);
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}
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}
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// set land maybe flag
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set_land_complete_maybe(land_detector >= LAND_DETECTOR_MAYBE_TRIGGER_SEC*MAIN_LOOP_RATE);
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}
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// update_throttle_thr_mix - sets motors throttle_low_comp value depending upon vehicle state
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// low values favour pilot/autopilot throttle over attitude control, high values favour attitude control over throttle
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// has no effect when throttle is above hover throttle
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static void update_throttle_thr_mix()
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{
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if (mode_has_manual_throttle(control_mode)) {
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// manual throttle
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if(!motors.armed() || channel_throttle->control_in <= 0) {
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motors.set_throttle_mix_min();
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} else {
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motors.set_throttle_mix_mid();
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}
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} else {
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// autopilot controlled throttle
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// check for aggressive flight requests - requested roll or pitch angle below 15 degrees
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const Vector3f angle_target = attitude_control.angle_ef_targets();
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bool large_angle_request = (pythagorous2(angle_target.x, angle_target.y) > 1500.0f);
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// check for large external disturbance - angle error over 30 degrees
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const Vector3f angle_error = attitude_control.angle_bf_error();
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bool large_angle_error = (pythagorous2(angle_error.x, angle_error.y) > 3000.0f);
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// check for large acceleration - falling or high turbulence
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Vector3f accel_ef = ahrs.get_accel_ef_blended();
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accel_ef.z += GRAVITY_MSS;
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bool accel_moving = (accel_ef.length() > 3.0f);
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// check for requested decent
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bool descent_not_demanded = pos_control.get_desired_velocity().z >= 0.0f;
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if ( large_angle_request || large_angle_error || accel_moving || descent_not_demanded) {
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motors.set_throttle_mix_max();
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} else {
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motors.set_throttle_mix_min();
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}
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}
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}
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