ardupilot/ArduCopter/surface_tracking.cpp

124 lines
4.8 KiB
C++

#include "Copter.h"
// adjust_climb_rate - hold copter at the desired distance above the
// ground; returns climb rate (in cm/s) which should be passed to
// the position controller
float Copter::SurfaceTracking::adjust_climb_rate(float target_rate)
{
#if RANGEFINDER_ENABLED == ENABLED
// check tracking state and that range finders are healthy
if ((surface == Surface::NONE) ||
((surface == Surface::GROUND) && (!copter.rangefinder_alt_ok() || (copter.rangefinder_state.glitch_count != 0))) ||
((surface == Surface::CEILING) && !copter.rangefinder_up_ok()) || (copter.rangefinder_up_state.glitch_count != 0)) {
return target_rate;
}
// calculate current ekf based altitude error
const float current_alt_error = copter.pos_control->get_alt_target() - copter.inertial_nav.get_altitude();
// init based on tracking direction/state
RangeFinderState &rf_state = (surface == Surface::GROUND) ? copter.rangefinder_state : copter.rangefinder_up_state;
const float dir = (surface == Surface::GROUND) ? 1.0f : -1.0f;
// reset target altitude if this controller has just been engaged
// target has been changed between upwards vs downwards
// or glitch has cleared
const uint32_t now = millis();
if ((now - last_update_ms > SURFACE_TRACKING_TIMEOUT_MS) ||
reset_target ||
(last_glitch_cleared_ms != rf_state.glitch_cleared_ms)) {
target_dist_cm = rf_state.alt_cm + (dir * current_alt_error);
reset_target = false;
last_glitch_cleared_ms = rf_state.glitch_cleared_ms;\
}
last_update_ms = now;
// adjust rangefinder target alt if motors have not hit their limits
if ((target_rate<0 && !copter.motors->limit.throttle_lower) || (target_rate>0 && !copter.motors->limit.throttle_upper)) {
target_dist_cm += dir * target_rate * copter.G_Dt;
}
valid_for_logging = true;
#if AC_AVOID_ENABLED == ENABLED
// upward facing terrain following never gets closer than avoidance margin
if (surface == Surface::CEILING) {
const float margin_cm = copter.avoid.enabled() ? copter.avoid.get_margin() * 100.0f : 0.0f;
target_dist_cm = MAX(target_dist_cm, margin_cm);
}
#endif
// calc desired velocity correction from target rangefinder alt vs actual rangefinder alt (remove the error already passed to Altitude controller to avoid oscillations)
const float distance_error = (target_dist_cm - rf_state.alt_cm) - (dir * current_alt_error);
float velocity_correction = dir * distance_error * copter.g.rangefinder_gain;
velocity_correction = constrain_float(velocity_correction, -SURFACE_TRACKING_VELZ_MAX, SURFACE_TRACKING_VELZ_MAX);
// return combined pilot climb rate + rate to correct rangefinder alt error
return (target_rate + velocity_correction);
#else
return target_rate;
#endif
}
// get target altitude (in cm) above ground
// returns true if there is a valid target
bool Copter::SurfaceTracking::get_target_alt_cm(float &_target_alt_cm) const
{
// fail if we are not tracking downwards
if (surface != Surface::GROUND) {
return false;
}
// check target has been updated recently
if (AP_HAL::millis() - last_update_ms > SURFACE_TRACKING_TIMEOUT_MS) {
return false;
}
_target_alt_cm = target_dist_cm;
return true;
}
// set target altitude (in cm) above ground
void Copter::SurfaceTracking::set_target_alt_cm(float _target_alt_cm)
{
// fail if we are not tracking downwards
if (surface != Surface::GROUND) {
return;
}
target_dist_cm = _target_alt_cm;
last_update_ms = AP_HAL::millis();
}
bool Copter::SurfaceTracking::get_target_dist_for_logging(float &target_dist) const
{
if (!valid_for_logging || (surface == Surface::NONE)) {
return false;
}
target_dist = target_dist_cm * 0.01f;
return true;
}
float Copter::SurfaceTracking::get_dist_for_logging() const
{
return ((surface == Surface::CEILING) ? copter.rangefinder_up_state.alt_cm : copter.rangefinder_state.alt_cm) * 0.01f;
}
// set direction
void Copter::SurfaceTracking::set_surface(Surface new_surface)
{
if (surface == new_surface) {
return;
}
// check we have a range finder in the correct direction
if ((new_surface == Surface::GROUND) && !copter.rangefinder.has_orientation(ROTATION_PITCH_270)) {
copter.gcs().send_text(MAV_SEVERITY_WARNING, "SurfaceTracking: no downward rangefinder");
AP_Notify::events.user_mode_change_failed = 1;
return;
}
if ((new_surface == Surface::CEILING) && !copter.rangefinder.has_orientation(ROTATION_PITCH_90)) {
copter.gcs().send_text(MAV_SEVERITY_WARNING, "SurfaceTracking: no upward rangefinder");
AP_Notify::events.user_mode_change_failed = 1;
return;
}
surface = new_surface;
reset_target = true;
}