AC_WPNav: Support changing update period

This commit is contained in:
Leonard Hall 2022-12-05 15:54:26 +10:30 committed by Randy Mackay
parent 0f1ce59cd9
commit c91c652b05
2 changed files with 24 additions and 27 deletions

View File

@ -139,10 +139,10 @@ void AC_Loiter::soften_for_landing()
// dt should be the time (in seconds) since the last call to this function
void AC_Loiter::set_pilot_desired_acceleration(float euler_roll_angle_cd, float euler_pitch_angle_cd)
{
const float dt = _pos_control.get_dt();
const float dt = _attitude_control.get_dt();
// Convert from centidegrees on public interface to radians
const float euler_roll_angle = radians(euler_roll_angle_cd*0.01f);
const float euler_pitch_angle = radians(euler_pitch_angle_cd*0.01f);
const float euler_roll_angle = radians(euler_roll_angle_cd * 0.01f);
const float euler_pitch_angle = radians(euler_pitch_angle_cd * 0.01f);
// convert our desired attitude to an acceleration vector assuming we are not accelerating vertically
const Vector3f desired_euler {euler_roll_angle, euler_pitch_angle, _ahrs.yaw};
@ -188,7 +188,7 @@ float AC_Loiter::get_angle_max_cd() const
/// run the loiter controller
void AC_Loiter::update(bool avoidance_on)
{
calc_desired_velocity(_pos_control.get_dt(), avoidance_on);
calc_desired_velocity(avoidance_on);
_pos_control.update_xy_controller();
}
@ -201,20 +201,22 @@ void AC_Loiter::sanity_check_params()
/// calc_desired_velocity - updates desired velocity (i.e. feed forward) with pilot requested acceleration and fake wind resistance
/// updated velocity sent directly to position controller
void AC_Loiter::calc_desired_velocity(float nav_dt, bool avoidance_on)
void AC_Loiter::calc_desired_velocity(bool avoidance_on)
{
float ekfGndSpdLimit, ahrsControlScaleXY;
AP::ahrs().getControlLimits(ekfGndSpdLimit, ahrsControlScaleXY);
const float dt = _pos_control.get_dt();
// calculate a loiter speed limit which is the minimum of the value set by the LOITER_SPEED
// parameter and the value set by the EKF to observe optical flow limits
float gnd_speed_limit_cms = MIN(_speed_cms, ekfGndSpdLimit*100.0f);
float gnd_speed_limit_cms = MIN(_speed_cms, ekfGndSpdLimit * 100.0f);
gnd_speed_limit_cms = MAX(gnd_speed_limit_cms, LOITER_SPEED_MIN);
float pilot_acceleration_max = angle_to_accel(get_angle_max_cd()*0.01) * 100;
float pilot_acceleration_max = angle_to_accel(get_angle_max_cd() * 0.01) * 100;
// range check nav_dt
if (nav_dt < 0) {
// range check dt
if (is_negative(dt)) {
return;
}
@ -223,39 +225,34 @@ void AC_Loiter::calc_desired_velocity(float nav_dt, bool avoidance_on)
Vector2f desired_vel{desired_vel_3d.x,desired_vel_3d.y};
// update the desired velocity using our predicted acceleration
desired_vel.x += _predicted_accel.x * nav_dt;
desired_vel.y += _predicted_accel.y * nav_dt;
desired_vel.x += _predicted_accel.x * dt;
desired_vel.y += _predicted_accel.y * dt;
Vector2f loiter_accel_brake;
float desired_speed = desired_vel.length();
if (!is_zero(desired_speed)) {
Vector2f desired_vel_norm = desired_vel/desired_speed;
// TODO: consider using a velocity squared relationship like
// pilot_acceleration_max*(desired_speed/gnd_speed_limit_cms)^2;
// the drag characteristic of a multirotor should be examined to generate a curve
// we could add a expo function here to fine tune it
Vector2f desired_vel_norm = desired_vel / desired_speed;
// calculate a drag acceleration based on the desired speed.
float drag_decel = pilot_acceleration_max*desired_speed/gnd_speed_limit_cms;
float drag_decel = pilot_acceleration_max * desired_speed / gnd_speed_limit_cms;
// calculate a braking acceleration if sticks are at zero
float loiter_brake_accel = 0.0f;
if (_desired_accel.is_zero()) {
if ((AP_HAL::millis()-_brake_timer) > _brake_delay * 1000.0f) {
if ((AP_HAL::millis() - _brake_timer) > _brake_delay * 1000.0f) {
float brake_gain = _pos_control.get_vel_xy_pid().kP() * 0.5f;
loiter_brake_accel = constrain_float(sqrt_controller(desired_speed, brake_gain, _brake_jerk_max_cmsss, nav_dt), 0.0f, _brake_accel_cmss);
loiter_brake_accel = constrain_float(sqrt_controller(desired_speed, brake_gain, _brake_jerk_max_cmsss, dt), 0.0f, _brake_accel_cmss);
}
} else {
loiter_brake_accel = 0.0f;
_brake_timer = AP_HAL::millis();
}
_brake_accel += constrain_float(loiter_brake_accel-_brake_accel, -_brake_jerk_max_cmsss*nav_dt, _brake_jerk_max_cmsss*nav_dt);
loiter_accel_brake = desired_vel_norm*_brake_accel;
_brake_accel += constrain_float(loiter_brake_accel - _brake_accel, -_brake_jerk_max_cmsss * dt, _brake_jerk_max_cmsss * dt);
loiter_accel_brake = desired_vel_norm * _brake_accel;
// update the desired velocity using the drag and braking accelerations
desired_speed = MAX(desired_speed-(drag_decel+_brake_accel)*nav_dt,0.0f);
desired_vel = desired_vel_norm*desired_speed;
desired_speed = MAX(desired_speed - (drag_decel + _brake_accel) * dt, 0.0f);
desired_vel = desired_vel_norm * desired_speed;
}
// add braking to the desired acceleration
@ -275,7 +272,7 @@ void AC_Loiter::calc_desired_velocity(float nav_dt, bool avoidance_on)
AC_Avoid *_avoid = AP::ac_avoid();
if (_avoid != nullptr) {
Vector3f avoidance_vel_3d{desired_vel.x, desired_vel.y, 0.0f};
_avoid->adjust_velocity(avoidance_vel_3d, _pos_control.get_pos_xy_p().kP(), _accel_cmss, _pos_control.get_pos_z_p().kP(), _pos_control.get_max_accel_z_cmss(), nav_dt);
_avoid->adjust_velocity(avoidance_vel_3d, _pos_control.get_pos_xy_p().kP(), _accel_cmss, _pos_control.get_pos_z_p().kP(), _pos_control.get_max_accel_z_cmss(), dt);
desired_vel = Vector2f{avoidance_vel_3d.x, avoidance_vel_3d.y};
}
}
@ -285,7 +282,7 @@ void AC_Loiter::calc_desired_velocity(float nav_dt, bool avoidance_on)
Vector2p target_pos = _pos_control.get_pos_target_cm().xy();
// update the target position using our predicted velocity
target_pos += (desired_vel * nav_dt).topostype();
target_pos += (desired_vel * dt).topostype();
// send adjusted feed forward acceleration and velocity back to the Position Controller
_pos_control.set_pos_vel_accel_xy(target_pos, desired_vel, _desired_accel);

View File

@ -64,7 +64,7 @@ protected:
/// updates desired velocity (i.e. feed forward) with pilot requested acceleration and fake wind resistance
/// updated velocity sent directly to position controller
void calc_desired_velocity(float nav_dt, bool avoidance_on = true);
void calc_desired_velocity(bool avoidance_on = true);
// references and pointers to external libraries
const AP_InertialNav& _inav;