ardupilot/ArduSub/control_poshold.cpp

135 lines
5.2 KiB
C++

// ArduSub position hold flight mode
// GPS required
// Jacob Walser August 2016
#include "Sub.h"
#if POSHOLD_ENABLED == ENABLED
// poshold_init - initialise PosHold controller
bool Sub::poshold_init()
{
// fail to initialise PosHold mode if no GPS lock
if (!position_ok()) {
return false;
}
// initialize vertical speeds and acceleration
pos_control.set_max_speed_z(-get_pilot_speed_dn(), g.pilot_speed_up);
pos_control.set_max_accel_z(g.pilot_accel_z);
// initialise position and desired velocity
pos_control.set_alt_target(inertial_nav.get_altitude());
pos_control.set_desired_velocity_z(inertial_nav.get_velocity_z());
// set target to current position
// only init here as we can switch to PosHold in flight with a velocity <> 0 that will be used as _last_vel in PosControl and never updated again as we inhibit Reset_I
loiter_nav.clear_pilot_desired_acceleration();
loiter_nav.init_target();
last_pilot_heading = ahrs.yaw_sensor;
return true;
}
// poshold_run - runs the PosHold controller
// should be called at 100hz or more
void Sub::poshold_run()
{
uint32_t tnow = AP_HAL::millis();
// if not armed set throttle to zero and exit immediately
if (!motors.armed()) {
motors.set_desired_spool_state(AP_Motors::DESIRED_GROUND_IDLE);
loiter_nav.clear_pilot_desired_acceleration();
loiter_nav.init_target();
attitude_control.set_throttle_out_unstabilized(0,true,g.throttle_filt);
pos_control.relax_alt_hold_controllers(motors.get_throttle_hover());
return;
}
// set motors to full range
motors.set_desired_spool_state(AP_Motors::DESIRED_THROTTLE_UNLIMITED);
// run loiter controller
loiter_nav.update();
///////////////////////
// update xy outputs //
float pilot_lateral = channel_lateral->norm_input();
float pilot_forward = channel_forward->norm_input();
float lateral_out = 0;
float forward_out = 0;
// Allow pilot to reposition the sub
if (fabsf(pilot_lateral) > 0.1 || fabsf(pilot_forward) > 0.1) {
lateral_out = pilot_lateral;
forward_out = pilot_forward;
loiter_nav.clear_pilot_desired_acceleration();
loiter_nav.init_target(); // initialize target to current position after repositioning
} else {
translate_wpnav_rp(lateral_out, forward_out);
}
motors.set_lateral(lateral_out);
motors.set_forward(forward_out);
/////////////////////
// Update attitude //
// get pilot's desired yaw rate
float target_yaw_rate = get_pilot_desired_yaw_rate(channel_yaw->get_control_in());
// convert pilot input to lean angles
// To-Do: convert get_pilot_desired_lean_angles to return angles as floats
float target_roll, target_pitch;
get_pilot_desired_lean_angles(channel_roll->get_control_in(), channel_pitch->get_control_in(), target_roll, target_pitch, aparm.angle_max);
// update attitude controller targets
if (!is_zero(target_yaw_rate)) { // call attitude controller with rate yaw determined by pilot input
attitude_control.input_euler_angle_roll_pitch_euler_rate_yaw(target_roll, target_pitch, target_yaw_rate);
last_pilot_heading = ahrs.yaw_sensor;
last_pilot_yaw_input_ms = tnow; // time when pilot last changed heading
} else { // hold current heading
// this check is required to prevent bounce back after very fast yaw maneuvers
// the inertia of the vehicle causes the heading to move slightly past the point when pilot input actually stopped
if (tnow < last_pilot_yaw_input_ms + 250) { // give 250ms to slow down, then set target heading
target_yaw_rate = 0; // Stop rotation on yaw axis
// call attitude controller with target yaw rate = 0 to decelerate on yaw axis
attitude_control.input_euler_angle_roll_pitch_euler_rate_yaw(target_roll, target_pitch, target_yaw_rate);
last_pilot_heading = ahrs.yaw_sensor; // update heading to hold
} else { // call attitude controller holding absolute absolute bearing
attitude_control.input_euler_angle_roll_pitch_yaw(target_roll, target_pitch, last_pilot_heading, true);
}
}
///////////////////
// Update z axis //
// get pilot desired climb rate
float target_climb_rate = get_pilot_desired_climb_rate(channel_throttle->get_control_in());
target_climb_rate = constrain_float(target_climb_rate, -get_pilot_speed_dn(), g.pilot_speed_up);
// adjust climb rate using rangefinder
if (rangefinder_alt_ok()) {
// if rangefinder is ok, use surface tracking
target_climb_rate = get_surface_tracking_climb_rate(target_climb_rate, pos_control.get_alt_target(), G_Dt);
}
// call z axis position controller
if (ap.at_bottom) {
pos_control.relax_alt_hold_controllers(motors.get_throttle_hover()); // clear velocity and position targets, and integrator
pos_control.set_alt_target(inertial_nav.get_altitude() + 10.0f); // set target to 10 cm above bottom
} else {
pos_control.set_alt_target_from_climb_rate_ff(target_climb_rate, G_Dt, false);
}
pos_control.update_z_controller();
}
#endif // POSHOLD_ENABLED == ENABLED