ardupilot/libraries/AC_AutoTune/AC_AutoTune.cpp

827 lines
27 KiB
C++

#include "AC_AutoTune_config.h"
#if AC_AUTOTUNE_ENABLED
#include "AC_AutoTune.h"
#include <AP_Logger/AP_Logger.h>
#include <AP_Scheduler/AP_Scheduler.h>
#include <AP_Notify/AP_Notify.h>
#include <GCS_MAVLink/GCS.h>
#include <AP_Vehicle/AP_Vehicle_Type.h>
#define AUTOTUNE_PILOT_OVERRIDE_TIMEOUT_MS 500 // restart tuning if pilot has left sticks in middle for 2 seconds
#if APM_BUILD_TYPE(APM_BUILD_ArduPlane)
# define AUTOTUNE_LEVEL_ANGLE_CD 500 // angle which qualifies as level (Plane uses more relaxed 5deg)
# define AUTOTUNE_LEVEL_RATE_RP_CD 1000 // rate which qualifies as level for roll and pitch (Plane uses more relaxed 10deg/sec)
#else
# define AUTOTUNE_LEVEL_ANGLE_CD 250 // angle which qualifies as level
# define AUTOTUNE_LEVEL_RATE_RP_CD 500 // rate which qualifies as level for roll and pitch
#endif
#define AUTOTUNE_LEVEL_RATE_Y_CD 750 // rate which qualifies as level for yaw
#define AUTOTUNE_REQUIRED_LEVEL_TIME_MS 250 // time we require the aircraft to be level before starting next test
#define AUTOTUNE_LEVEL_TIMEOUT_MS 2000 // time out for level
#define AUTOTUNE_LEVEL_WARNING_INTERVAL_MS 5000 // level failure warning messages sent at this interval to users
AC_AutoTune::AC_AutoTune()
{
}
// autotune_init - should be called when autotune mode is selected
bool AC_AutoTune::init_internals(bool _use_poshold,
AC_AttitudeControl *_attitude_control,
AC_PosControl *_pos_control,
AP_AHRS_View *_ahrs_view,
AP_InertialNav *_inertial_nav)
{
use_poshold = _use_poshold;
attitude_control = _attitude_control;
pos_control = _pos_control;
ahrs_view = _ahrs_view;
inertial_nav = _inertial_nav;
motors = AP_Motors::get_singleton();
const uint32_t now = AP_HAL::millis();
// exit immediately if motor are not armed
if ((motors == nullptr) || !motors->armed()) {
return false;
}
// initialise position controller
init_position_controller();
switch (mode) {
case FAILED:
// fall through to restart the tuning
FALLTHROUGH;
case UNINITIALISED:
// autotune has never been run
// so store current gains as original gains
backup_gains_and_initialise();
// advance mode to tuning
mode = TUNING;
// send message to ground station that we've started tuning
update_gcs(AUTOTUNE_MESSAGE_STARTED);
break;
case TUNING:
// reset test variables for each vehicle
reset_vehicle_test_variables();
// we are restarting tuning so restart where we left off
step = WAITING_FOR_LEVEL;
step_start_time_ms = now;
level_start_time_ms = now;
// reset gains to tuning-start gains (i.e. low I term)
load_gains(GAIN_INTRA_TEST);
LOGGER_WRITE_EVENT(LogEvent::AUTOTUNE_RESTART);
update_gcs(AUTOTUNE_MESSAGE_STARTED);
break;
case SUCCESS:
// we have completed a tune and the pilot wishes to test the new gains
load_gains(GAIN_TUNED);
update_gcs(AUTOTUNE_MESSAGE_TESTING);
LOGGER_WRITE_EVENT(LogEvent::AUTOTUNE_PILOT_TESTING);
break;
}
have_position = false;
return true;
}
// stop - should be called when the ch7/ch8 switch is switched OFF
void AC_AutoTune::stop()
{
// set gains to their original values
load_gains(GAIN_ORIGINAL);
// re-enable angle-to-rate request limits
attitude_control->use_sqrt_controller(true);
update_gcs(AUTOTUNE_MESSAGE_STOPPED);
LOGGER_WRITE_EVENT(LogEvent::AUTOTUNE_OFF);
// Note: we leave the mode as it was so that we know how the autotune ended
// we expect the caller will change the flight mode back to the flight mode indicated by the flight mode switch
}
// Autotune aux function trigger
void AC_AutoTune::do_aux_function(const RC_Channel::AuxSwitchPos ch_flag)
{
if (mode != TuneMode::SUCCESS) {
if (ch_flag == RC_Channel::AuxSwitchPos::HIGH) {
gcs().send_text(MAV_SEVERITY_NOTICE,"AutoTune: must be complete to test gains");
}
return;
}
switch(ch_flag) {
case RC_Channel::AuxSwitchPos::LOW:
// load original gains
load_gains(GainType::GAIN_ORIGINAL);
update_gcs(AUTOTUNE_MESSAGE_TESTING_END);
break;
case RC_Channel::AuxSwitchPos::MIDDLE:
// Middle position is unused for now
break;
case RC_Channel::AuxSwitchPos::HIGH:
// Load tuned gains
load_gains(GainType::GAIN_TUNED);
update_gcs(AUTOTUNE_MESSAGE_TESTING);
break;
}
have_pilot_testing_command = true;
}
// Possibly save gains, called on disarm
void AC_AutoTune::disarmed(const bool in_autotune_mode)
{
// True if pilot is testing tuned gains
const bool testing_tuned = have_pilot_testing_command && (loaded_gains == GainType::GAIN_TUNED);
// True if in autotune mode and no pilot testing commands have been received
const bool tune_complete_no_testing = !have_pilot_testing_command && in_autotune_mode;
if (tune_complete_no_testing || testing_tuned) {
save_tuning_gains();
} else {
reset();
}
}
// initialise position controller
bool AC_AutoTune::init_position_controller(void)
{
// initialize vertical maximum speeds and acceleration
init_z_limits();
// initialise the vertical position controller
pos_control->init_z_controller();
return true;
}
void AC_AutoTune::send_step_string()
{
if (pilot_override) {
GCS_SEND_TEXT(MAV_SEVERITY_INFO, "AutoTune: Paused: Pilot Override Active");
return;
}
switch (step) {
case WAITING_FOR_LEVEL:
GCS_SEND_TEXT(MAV_SEVERITY_INFO, "AutoTune: Leveling");
return;
case UPDATE_GAINS:
GCS_SEND_TEXT(MAV_SEVERITY_INFO, "AutoTune: Updating Gains");
return;
case ABORT:
GCS_SEND_TEXT(MAV_SEVERITY_INFO, "AutoTune: Aborting Test");
return;
case TESTING:
GCS_SEND_TEXT(MAV_SEVERITY_INFO, "AutoTune: Testing");
return;
}
GCS_SEND_TEXT(MAV_SEVERITY_INFO, "AutoTune: unknown step");
}
const char *AC_AutoTune::type_string() const
{
switch (tune_type) {
case RD_UP:
return "Rate D Up";
case RD_DOWN:
return "Rate D Down";
case RP_UP:
return "Rate P Up";
case RFF_UP:
return "Rate FF Up";
case SP_UP:
return "Angle P Up";
case SP_DOWN:
return "Angle P Down";
case MAX_GAINS:
return "Find Max Gains";
case TUNE_CHECK:
return "Check Tune Frequency Response";
case TUNE_COMPLETE:
return "Tune Complete";
}
return "";
// this should never happen
INTERNAL_ERROR(AP_InternalError::error_t::flow_of_control);
}
// return current axis string
const char *AC_AutoTune::axis_string() const
{
switch (axis) {
case AxisType::ROLL:
return "Roll";
case AxisType::PITCH:
return "Pitch";
case AxisType::YAW:
return "Yaw(E)";
case AxisType::YAW_D:
return "Yaw(D)";
}
return "";
}
// run - runs the autotune flight mode
// should be called at 100hz or more
void AC_AutoTune::run()
{
// initialize vertical speeds and acceleration
init_z_limits();
// if not auto armed or motor interlock not enabled set throttle to zero and exit immediately
// this should not actually be possible because of the init() checks
if (!motors->armed() || !motors->get_interlock()) {
motors->set_desired_spool_state(AP_Motors::DesiredSpoolState::GROUND_IDLE);
attitude_control->set_throttle_out(0.0f, true, 0.0f);
pos_control->relax_z_controller(0.0f);
return;
}
float target_roll_cd, target_pitch_cd, target_yaw_rate_cds;
get_pilot_desired_rp_yrate_cd(target_roll_cd, target_pitch_cd, target_yaw_rate_cds);
// get pilot desired climb rate
const float target_climb_rate_cms = get_pilot_desired_climb_rate_cms();
const bool zero_rp_input = is_zero(target_roll_cd) && is_zero(target_pitch_cd);
const uint32_t now = AP_HAL::millis();
if (mode != SUCCESS) {
if (!zero_rp_input || !is_zero(target_yaw_rate_cds) || !is_zero(target_climb_rate_cms)) {
if (!pilot_override) {
pilot_override = true;
// set gains to their original values
load_gains(GAIN_ORIGINAL);
attitude_control->use_sqrt_controller(true);
}
// reset pilot override time
override_time = now;
if (!zero_rp_input) {
// only reset position on roll or pitch input
have_position = false;
}
} else if (pilot_override) {
// check if we should resume tuning after pilot's override
if (now - override_time > AUTOTUNE_PILOT_OVERRIDE_TIMEOUT_MS) {
pilot_override = false; // turn off pilot override
// set gains to their intra-test values (which are very close to the original gains)
// load_gains(GAIN_INTRA_TEST); //I think we should be keeping the originals here to let the I term settle quickly
step = WAITING_FOR_LEVEL; // set tuning step back from beginning
step_start_time_ms = now;
level_start_time_ms = now;
desired_yaw_cd = ahrs_view->yaw_sensor;
}
}
}
if (pilot_override) {
if (now - last_pilot_override_warning > 1000) {
GCS_SEND_TEXT(MAV_SEVERITY_INFO, "AutoTune: pilot overrides active");
last_pilot_override_warning = now;
}
}
if (zero_rp_input) {
// pilot input on throttle and yaw will still use position hold if enabled
get_poshold_attitude(target_roll_cd, target_pitch_cd, desired_yaw_cd);
}
// set motors to full range
motors->set_desired_spool_state(AP_Motors::DesiredSpoolState::THROTTLE_UNLIMITED);
// if pilot override call attitude controller
if (pilot_override || mode != TUNING) {
attitude_control->input_euler_angle_roll_pitch_euler_rate_yaw(target_roll_cd, target_pitch_cd, target_yaw_rate_cds);
} else {
// somehow get attitude requests from autotuning
control_attitude();
// tell the user what's going on
do_gcs_announcements();
}
// call position controller
pos_control->set_pos_target_z_from_climb_rate_cm(target_climb_rate_cms);
pos_control->update_z_controller();
}
// return true if vehicle is close to level
bool AC_AutoTune::currently_level()
{
// abort AutoTune if we pass 2 * AUTOTUNE_LEVEL_TIMEOUT_MS
const uint32_t now_ms = AP_HAL::millis();
if (now_ms - level_start_time_ms > 3 * AUTOTUNE_LEVEL_TIMEOUT_MS) {
GCS_SEND_TEXT(MAV_SEVERITY_CRITICAL, "AutoTune: Failed to level, please tune manually");
mode = FAILED;
LOGGER_WRITE_EVENT(LogEvent::AUTOTUNE_FAILED);
}
// slew threshold to ensure sufficient settling time for aircraft unable to obtain small thresholds
// relax threshold if we pass AUTOTUNE_LEVEL_TIMEOUT_MS
const float threshold_mul = constrain_float((float)(now_ms - level_start_time_ms) / (float)AUTOTUNE_LEVEL_TIMEOUT_MS, 0.0, 2.0);
if (fabsf(ahrs_view->roll_sensor - roll_cd) > threshold_mul * AUTOTUNE_LEVEL_ANGLE_CD) {
return false;
}
if (fabsf(ahrs_view->pitch_sensor - pitch_cd) > threshold_mul * AUTOTUNE_LEVEL_ANGLE_CD) {
return false;
}
if (fabsf(wrap_180_cd(ahrs_view->yaw_sensor - desired_yaw_cd)) > threshold_mul * AUTOTUNE_LEVEL_ANGLE_CD) {
return false;
}
if ((ToDeg(ahrs_view->get_gyro().x) * 100.0f) > threshold_mul * AUTOTUNE_LEVEL_RATE_RP_CD) {
return false;
}
if ((ToDeg(ahrs_view->get_gyro().y) * 100.0f) > threshold_mul * AUTOTUNE_LEVEL_RATE_RP_CD) {
return false;
}
if ((ToDeg(ahrs_view->get_gyro().z) * 100.0f) > threshold_mul * AUTOTUNE_LEVEL_RATE_Y_CD) {
return false;
}
return true;
}
// main state machine to level vehicle, perform a test and update gains
// directly updates attitude controller with targets
void AC_AutoTune::control_attitude()
{
rotation_rate = 0.0f; // rotation rate in radians/second
lean_angle = 0.0f;
const float direction_sign = positive_direction ? 1.0f : -1.0f;
const uint32_t now = AP_HAL::millis();
// check tuning step
switch (step) {
case WAITING_FOR_LEVEL: {
// Note: we should be using intra-test gains (which are very close to the original gains but have lower I)
// re-enable rate limits
attitude_control->use_sqrt_controller(true);
get_poshold_attitude(roll_cd, pitch_cd, desired_yaw_cd);
// hold level attitude
attitude_control->input_euler_angle_roll_pitch_yaw(roll_cd, pitch_cd, desired_yaw_cd, true);
// hold the copter level for 0.5 seconds before we begin a twitch
// reset counter if we are no longer level
if (!currently_level()) {
step_start_time_ms = now;
}
// if we have been level for a sufficient amount of time (0.5 seconds) move onto tuning step
if (now - step_start_time_ms > AUTOTUNE_REQUIRED_LEVEL_TIME_MS) {
// initiate variables for next step
step = TESTING;
step_start_time_ms = now;
step_time_limit_ms = get_testing_step_timeout_ms();
// set gains to their to-be-tested values
load_gains(GAIN_TEST);
} else {
// when waiting for level we use the intra-test gains
load_gains(GAIN_INTRA_TEST);
}
// Initialize test-specific variables
switch (axis) {
case AxisType::ROLL:
start_rate = ToDeg(ahrs_view->get_gyro().x) * 100.0f;
start_angle = ahrs_view->roll_sensor;
break;
case AxisType::PITCH:
start_rate = ToDeg(ahrs_view->get_gyro().y) * 100.0f;
start_angle = ahrs_view->pitch_sensor;
break;
case AxisType::YAW:
case AxisType::YAW_D:
start_rate = ToDeg(ahrs_view->get_gyro().z) * 100.0f;
start_angle = ahrs_view->yaw_sensor;
break;
}
// tests must be initialized last as some rely on variables above
test_init();
break;
}
case TESTING: {
// Run the twitching step
load_gains(GAIN_TEST);
// run the test
test_run(axis, direction_sign);
// Check for failure causing reverse response
if (lean_angle <= -angle_lim_neg_rpy_cd()) {
step = WAITING_FOR_LEVEL;
positive_direction = twitch_reverse_direction();
step_start_time_ms = now;
level_start_time_ms = now;
}
// protect from roll over
if (attitude_control->lean_angle_deg() * 100 > angle_lim_max_rp_cd()) {
step = WAITING_FOR_LEVEL;
positive_direction = twitch_reverse_direction();
step_start_time_ms = now;
level_start_time_ms = now;
}
#if HAL_LOGGING_ENABLED
// log this iterations lean angle and rotation rate
Log_AutoTuneDetails();
ahrs_view->Write_Rate(*motors, *attitude_control, *pos_control);
log_pids();
#endif
if (axis == AxisType::YAW || axis == AxisType::YAW_D) {
desired_yaw_cd = ahrs_view->yaw_sensor;
}
break;
}
case UPDATE_GAINS:
// re-enable rate limits
attitude_control->use_sqrt_controller(true);
#if HAL_LOGGING_ENABLED
// log the latest gains
Log_AutoTune();
#endif
// Announce tune type test results
// must be done before updating method because this method changes parameters for next test
do_post_test_gcs_announcements();
switch (tune_type) {
// Check results after mini-step to increase rate D gain
case RD_UP:
updating_rate_d_up_all(axis);
break;
// Check results after mini-step to decrease rate D gain
case RD_DOWN:
updating_rate_d_down_all(axis);
break;
// Check results after mini-step to increase rate P gain
case RP_UP:
updating_rate_p_up_all(axis);
break;
// Check results after mini-step to increase stabilize P gain
case SP_DOWN:
updating_angle_p_down_all(axis);
break;
// Check results after mini-step to increase stabilize P gain
case SP_UP:
updating_angle_p_up_all(axis);
break;
case RFF_UP:
updating_rate_ff_up_all(axis);
break;
case MAX_GAINS:
updating_max_gains_all(axis);
break;
case TUNE_CHECK:
counter = AUTOTUNE_SUCCESS_COUNT;
FALLTHROUGH;
case TUNE_COMPLETE:
break;
}
// we've complete this step, finalize pids and move to next step
if (counter >= AUTOTUNE_SUCCESS_COUNT) {
// reset counter
counter = 0;
// reset scaling factor
step_scaler = 1.0f;
// set gains for post tune before moving to the next tuning type
set_gains_post_tune(axis);
// increment the tune type to the next one in tune sequence
next_tune_type(tune_type, false);
if (tune_type == TUNE_COMPLETE) {
// we've reached the end of a D-up-down PI-up-down tune type cycle
next_tune_type(tune_type, true);
report_final_gains(axis);
// advance to the next axis
bool complete = false;
switch (axis) {
case AxisType::ROLL:
axes_completed |= AUTOTUNE_AXIS_BITMASK_ROLL;
if (pitch_enabled()) {
axis = AxisType::PITCH;
} else if (yaw_enabled()) {
axis = AxisType::YAW;
} else if (yaw_d_enabled()) {
axis = AxisType::YAW_D;
} else {
complete = true;
}
break;
case AxisType::PITCH:
axes_completed |= AUTOTUNE_AXIS_BITMASK_PITCH;
if (yaw_enabled()) {
axis = AxisType::YAW;
} else if (yaw_d_enabled()) {
axis = AxisType::YAW_D;
} else {
complete = true;
}
break;
case AxisType::YAW:
axes_completed |= AUTOTUNE_AXIS_BITMASK_YAW;
if (yaw_d_enabled()) {
axis = AxisType::YAW_D;
} else {
complete = true;
}
break;
case AxisType::YAW_D:
axes_completed |= AUTOTUNE_AXIS_BITMASK_YAW_D;
complete = true;
break;
}
// if we've just completed all axes we have successfully completed the autotune
// change to TESTING mode to allow user to fly with new gains
if (complete) {
mode = SUCCESS;
update_gcs(AUTOTUNE_MESSAGE_SUCCESS);
LOGGER_WRITE_EVENT(LogEvent::AUTOTUNE_SUCCESS);
AP_Notify::events.autotune_complete = true;
// Return to original gains for landing
load_gains(GainType::GAIN_ORIGINAL);
} else {
AP_Notify::events.autotune_next_axis = true;
reset_update_gain_variables();
}
}
}
FALLTHROUGH;
case ABORT:
if (axis == AxisType::YAW || axis == AxisType::YAW_D) {
// todo: check to make sure we need this
attitude_control->input_euler_angle_roll_pitch_yaw(0.0f, 0.0f, ahrs_view->yaw_sensor, false);
}
// set gains to their intra-test values (which are very close to the original gains)
load_gains(GAIN_INTRA_TEST);
// reset testing step
step = WAITING_FOR_LEVEL;
positive_direction = twitch_reverse_direction();
step_start_time_ms = now;
level_start_time_ms = now;
step_time_limit_ms = AUTOTUNE_REQUIRED_LEVEL_TIME_MS;
break;
}
}
// backup_gains_and_initialise - store current gains as originals
// called before tuning starts to backup original gains
void AC_AutoTune::backup_gains_and_initialise()
{
const uint32_t now = AP_HAL::millis();
// initialise state because this is our first time
if (roll_enabled()) {
axis = AxisType::ROLL;
} else if (pitch_enabled()) {
axis = AxisType::PITCH;
} else if (yaw_enabled()) {
axis = AxisType::YAW;
} else if (yaw_d_enabled()) {
axis = AxisType::YAW_D;
}
// no axes are complete
axes_completed = 0;
// reset update gain variables for each vehicle
reset_update_gain_variables();
// start at the beginning of tune sequence
next_tune_type(tune_type, true);
step = WAITING_FOR_LEVEL;
positive_direction = false;
step_start_time_ms = now;
level_start_time_ms = now;
step_scaler = 1.0f;
desired_yaw_cd = ahrs_view->yaw_sensor;
}
/*
load a specified set of gains
*/
void AC_AutoTune::load_gains(enum GainType gain_type)
{
if (loaded_gains == gain_type) {
// Loaded gains are already of correct type
return;
}
loaded_gains = gain_type;
switch (gain_type) {
case GAIN_ORIGINAL:
load_orig_gains();
break;
case GAIN_INTRA_TEST:
load_intra_test_gains();
break;
case GAIN_TEST:
load_test_gains();
break;
case GAIN_TUNED:
load_tuned_gains();
break;
}
}
// update_gcs - send message to ground station
void AC_AutoTune::update_gcs(uint8_t message_id) const
{
switch (message_id) {
case AUTOTUNE_MESSAGE_STARTED:
GCS_SEND_TEXT(MAV_SEVERITY_INFO,"AutoTune: Started");
break;
case AUTOTUNE_MESSAGE_STOPPED:
GCS_SEND_TEXT(MAV_SEVERITY_INFO,"AutoTune: Stopped");
break;
case AUTOTUNE_MESSAGE_SUCCESS:
GCS_SEND_TEXT(MAV_SEVERITY_NOTICE,"AutoTune: Success");
break;
case AUTOTUNE_MESSAGE_FAILED:
GCS_SEND_TEXT(MAV_SEVERITY_NOTICE,"AutoTune: Failed");
break;
case AUTOTUNE_MESSAGE_TESTING:
case AUTOTUNE_MESSAGE_SAVED_GAINS:
GCS_SEND_TEXT(MAV_SEVERITY_NOTICE,"AutoTune: %s gains for %s%s%s%s",
(message_id == AUTOTUNE_MESSAGE_SAVED_GAINS) ? "Saved" : "Pilot Testing",
(axes_completed&AUTOTUNE_AXIS_BITMASK_ROLL)?"Roll ":"",
(axes_completed&AUTOTUNE_AXIS_BITMASK_PITCH)?"Pitch ":"",
(axes_completed&AUTOTUNE_AXIS_BITMASK_YAW)?"Yaw(E)":"",
(axes_completed&AUTOTUNE_AXIS_BITMASK_YAW_D)?"Yaw(D)":"");
break;
case AUTOTUNE_MESSAGE_TESTING_END:
GCS_SEND_TEXT(MAV_SEVERITY_NOTICE,"AutoTune: original gains restored");
break;
}
}
// axis helper functions
bool AC_AutoTune::roll_enabled() const
{
return get_axis_bitmask() & AUTOTUNE_AXIS_BITMASK_ROLL;
}
bool AC_AutoTune::pitch_enabled() const
{
return get_axis_bitmask() & AUTOTUNE_AXIS_BITMASK_PITCH;
}
bool AC_AutoTune::yaw_enabled() const
{
return get_axis_bitmask() & AUTOTUNE_AXIS_BITMASK_YAW;
}
bool AC_AutoTune::yaw_d_enabled() const
{
#if APM_BUILD_TYPE(APM_BUILD_Heli)
return false;
#else
return get_axis_bitmask() & AUTOTUNE_AXIS_BITMASK_YAW_D;
#endif
}
/*
check if we have a good position estimate
*/
bool AC_AutoTune::position_ok(void)
{
if (!AP::ahrs().have_inertial_nav()) {
// do not allow navigation with dcm position
return false;
}
// with EKF use filter status and ekf check
nav_filter_status filt_status = inertial_nav->get_filter_status();
// require a good absolute position and EKF must not be in const_pos_mode
return (filt_status.flags.horiz_pos_abs && !filt_status.flags.const_pos_mode);
}
// get attitude for slow position hold in autotune mode
void AC_AutoTune::get_poshold_attitude(float &roll_cd_out, float &pitch_cd_out, float &yaw_cd_out)
{
roll_cd_out = pitch_cd_out = 0;
if (!use_poshold) {
// we are not trying to hold position
return;
}
// do we know where we are? If not then don't do poshold
if (!position_ok()) {
return;
}
if (!have_position) {
have_position = true;
start_position = inertial_nav->get_position_neu_cm();
}
// don't go past 10 degrees, as autotune result would deteriorate too much
const float angle_max_cd = 1000;
// hit the 10 degree limit at 20 meters position error
const float dist_limit_cm = 2000;
// we only start adjusting yaw if we are more than 5m from the
// target position. That corresponds to a lean angle of 2.5 degrees
const float yaw_dist_limit_cm = 500;
Vector3f pdiff = inertial_nav->get_position_neu_cm() - start_position;
pdiff.z = 0;
float dist_cm = pdiff.length();
if (dist_cm < 10) {
// don't do anything within 10cm
return;
}
/*
very simple linear controller
*/
float scaling = constrain_float(angle_max_cd * dist_cm / dist_limit_cm, 0, angle_max_cd);
Vector2f angle_ne(pdiff.x, pdiff.y);
angle_ne *= scaling / dist_cm;
// rotate into body frame
pitch_cd_out = angle_ne.x * ahrs_view->cos_yaw() + angle_ne.y * ahrs_view->sin_yaw();
roll_cd_out = angle_ne.x * ahrs_view->sin_yaw() - angle_ne.y * ahrs_view->cos_yaw();
if (dist_cm < yaw_dist_limit_cm) {
// no yaw adjustment
return;
}
/*
also point so that twitching occurs perpendicular to the wind,
if we have drifted more than yaw_dist_limit_cm from the desired
position. This ensures that autotune doesn't have to deal with
more than 2.5 degrees of attitude on the axis it is tuning
*/
float target_yaw_cd = degrees(atan2f(pdiff.y, pdiff.x)) * 100;
if (axis == AxisType::PITCH) {
// for roll and yaw tuning we point along the wind, for pitch
// we point across the wind
target_yaw_cd += 9000;
}
// go to the nearest 180 degree mark, with 5 degree slop to prevent oscillation
if (fabsf(yaw_cd_out - target_yaw_cd) > 9500) {
target_yaw_cd += 18000;
}
yaw_cd_out = target_yaw_cd;
}
// get the next tune type
void AC_AutoTune::next_tune_type(TuneType &curr_tune_type, bool reset)
{
if (reset) {
set_tune_sequence();
tune_seq_curr = 0;
} else if (curr_tune_type == TUNE_COMPLETE) {
// leave tune_type as TUNE_COMPLETE to initiate next axis or exit autotune
return;
} else {
tune_seq_curr++;
}
curr_tune_type = tune_seq[tune_seq_curr];
}
#endif // AC_AUTOTUNE_ENABLED