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AC_PosControl: use 2-axis PI controller

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Leonard Hall 2015-01-29 15:50:14 +09:00 committed by Randy Mackay
parent 8d4f0ec80c
commit 349f1aeceb
2 changed files with 19 additions and 26 deletions
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39
libraries/AC_AttitudeControl/AC_PosControl.cpp
View File

@ -23,7 +23,7 @@ const AP_Param::GroupInfo AC_PosControl::var_info[] PROGMEM = {
AC_PosControl::AC_PosControl(const AP_AHRS& ahrs, const AP_InertialNav& inav,
const AP_Motors& motors, AC_AttitudeControl& attitude_control,
AC_P& p_alt_pos, AC_P& p_alt_rate, AC_PID& pid_alt_accel,
AC_P& p_pos_xy, AC_PID& pid_rate_lat, AC_PID& pid_rate_lon) :
AC_P& p_pos_xy, AC_PI_2D& pi_vel_xy) :
_ahrs(ahrs),
_inav(inav),
_motors(motors),
@ -32,8 +32,7 @@ AC_PosControl::AC_PosControl(const AP_AHRS& ahrs, const AP_InertialNav& inav,
_p_alt_rate(p_alt_rate),
_pid_alt_accel(pid_alt_accel),
_p_pos_xy(p_pos_xy),
_pid_rate_lat(pid_rate_lat),
_pid_rate_lon(pid_rate_lon),
_pi_vel_xy(pi_vel_xy),
_dt(POSCONTROL_DT_10HZ),
_dt_xy(POSCONTROL_DT_50HZ),
_last_update_xy_ms(0),
@ -89,8 +88,7 @@ void AC_PosControl::set_dt(float delta_sec)
void AC_PosControl::set_dt_xy(float dt_xy)
{
_dt_xy = dt_xy;
_pid_rate_lat.set_dt(dt_xy);
_pid_rate_lon.set_dt(dt_xy);
_pi_vel_xy.set_dt(dt_xy);
}
/// set_speed_z - sets maximum climb and descent rates
@ -519,8 +517,7 @@ void AC_PosControl::init_xy_controller(bool reset_I)
if (reset_I) {
// reset last velocity if this controller has just been engaged or dt is zero
lean_angles_to_accel(_accel_target.x, _accel_target.y);
_pid_rate_lat.set_integrator(_accel_target.x);
_pid_rate_lon.set_integrator(_accel_target.y);
_pi_vel_xy.set_integrator(_accel_target);
}
// flag reset required in rate to accel step
@ -572,8 +569,7 @@ void AC_PosControl::init_vel_controller_xyz()
// reset last velocity if this controller has just been engaged or dt is zero
lean_angles_to_accel(_accel_target.x, _accel_target.y);
_pid_rate_lat.set_integrator(_accel_target.x);
_pid_rate_lon.set_integrator(_accel_target.y);
_pi_vel_xy.set_integrator(_accel_target);
// flag reset required in rate to accel step
_flags.reset_desired_vel_to_pos = true;
@ -742,7 +738,7 @@ void AC_PosControl::rate_to_accel_xy(float dt, float ekfNavVelGainScaler)
{
const Vector3f &vel_curr = _inav.get_velocity(); // current velocity in cm/s
float accel_total; // total acceleration in cm/s/s
float lat_i, lon_i;
Vector2f vel_xy_p, vel_xy_i;
// reset last velocity target to current target
if (_flags.reset_rate_to_accel_xy) {
@ -773,25 +769,22 @@ void AC_PosControl::rate_to_accel_xy(float dt, float ekfNavVelGainScaler)
_vel_error.x = _vel_target.x - vel_curr.x;
_vel_error.y = _vel_target.y - vel_curr.y;
// call pid controller
_pid_rate_lat.set_input_filter_d(_vel_error.x);
_pid_rate_lon.set_input_filter_d(_vel_error.y);
// call pi controller
_pi_vel_xy.set_input(_vel_error);
// get current i term
lat_i = _pid_rate_lat.get_integrator();
lon_i = _pid_rate_lon.get_integrator();
// get p
vel_xy_p = _pi_vel_xy.get_p();
// update i term if we have not hit the accel or throttle limits OR the i term will reduce
if ((!_limit.accel_xy && !_motors.limit.throttle_upper) || ((lat_i>0&&_vel_error.x<0)||(lat_i<0&&_vel_error.x>0))) {
lat_i = _pid_rate_lat.get_i();
}
if ((!_limit.accel_xy && !_motors.limit.throttle_upper) || ((lon_i>0&&_vel_error.y<0)||(lon_i<0&&_vel_error.y>0))) {
lon_i = _pid_rate_lon.get_i();
if ((!_limit.accel_xy && !_motors.limit.throttle_upper)) {
vel_xy_i = _pi_vel_xy.get_i();
} else {
vel_xy_i = _pi_vel_xy.get_i_shrink();
}
// combine feed forward accel with PID output from velocity error and scale PID output to compensate for optical flow measurement induced EKF noise
_accel_target.x = _accel_feedforward.x + (_pid_rate_lat.get_p() + lat_i + _pid_rate_lat.get_d()) * ekfNavVelGainScaler;
_accel_target.y = _accel_feedforward.y + (_pid_rate_lon.get_p() + lon_i + _pid_rate_lon.get_d()) * ekfNavVelGainScaler;
_accel_target.x = _accel_feedforward.x + (vel_xy_p.x + vel_xy_i.x) * ekfNavVelGainScaler;
_accel_target.y = _accel_feedforward.y + (vel_xy_p.y + vel_xy_i.y) * ekfNavVelGainScaler;
// scale desired acceleration if it's beyond acceptable limit
// To-Do: move this check down to the accel_to_lean_angle method?

6
libraries/AC_AttitudeControl/AC_PosControl.h
View File

@ -6,6 +6,7 @@
#include <AP_Param.h>
#include <AP_Math.h>
#include <AC_PID.h> // PID library
#include <AC_PI_2D.h> // PID library (2-axis)
#include <AC_P.h> // P library
#include <AP_InertialNav.h> // Inertial Navigation library
#include <AC_AttitudeControl.h> // Attitude control library
@ -48,7 +49,7 @@ public:
AC_PosControl(const AP_AHRS& ahrs, const AP_InertialNav& inav,
const AP_Motors& motors, AC_AttitudeControl& attitude_control,
AC_P& p_alt_pos, AC_P& p_alt_rate, AC_PID& pid_alt_accel,
AC_P& p_pos_xy, AC_PID& pid_rate_lat, AC_PID& pid_rate_lon);
AC_P& p_pos_xy, AC_PI_2D& pi_vel_xy);
// xy_mode - specifies behavior of xy position controller
enum xy_mode {
@ -336,8 +337,7 @@ private:
AC_P& _p_alt_rate;
AC_PID& _pid_alt_accel;
AC_P& _p_pos_xy;
AC_PID& _pid_rate_lat;
AC_PID& _pid_rate_lon;
AC_PI_2D& _pi_vel_xy;
// parameters
AP_Float _throttle_hover; // estimated throttle required to maintain a level hover