ardupilot/libraries/AP_AHRS/AP_AHRS.h

272 lines
8.3 KiB
C++

/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
#ifndef __AP_AHRS_H__
#define __AP_AHRS_H__
/*
* AHRS (Attitude Heading Reference System) interface for ArduPilot
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*/
#include <AP_Math.h>
#include <inttypes.h>
#include <AP_Compass.h>
#include <AP_Airspeed.h>
#include <AP_GPS.h>
#include <AP_InertialSensor.h>
#include <AP_Baro.h>
#include <AP_Param.h>
#define AP_AHRS_TRIM_LIMIT 10.0f // maximum trim angle in degrees
class AP_AHRS
{
public:
// Constructor
AP_AHRS(AP_InertialSensor *ins, GPS *&gps) :
_ins(ins),
_gps(gps)
{
// load default values from var_info table
AP_Param::setup_object_defaults(this, var_info);
// base the ki values by the sensors maximum drift
// rate. The APM2 has gyros which are much less drift
// prone than the APM1, so we should have a lower ki,
// which will make us less prone to increasing omegaI
// incorrectly due to sensor noise
_gyro_drift_limit = ins->get_gyro_drift_rate();
// enable centrifugal correction by default
_flags.correct_centrifugal = true;
}
// init sets up INS board orientation
virtual void init() {
set_orientation();
};
// Accessors
void set_fly_forward(bool b) {
_flags.fly_forward = b;
}
void set_wind_estimation(bool b) {
_flags.wind_estimation = b;
}
void set_compass(Compass *compass) {
_compass = compass;
set_orientation();
}
// allow for runtime change of orientation
// this makes initial config easier
void set_orientation() {
_ins->set_board_orientation((enum Rotation)_board_orientation.get());
if (_compass != NULL) {
_compass->set_board_orientation((enum Rotation)_board_orientation.get());
}
}
void set_airspeed(AP_Airspeed *airspeed) {
_airspeed = airspeed;
}
AP_InertialSensor* get_ins() const {
return _ins;
}
// accelerometer values in the earth frame in m/s/s
const Vector3f &get_accel_ef(void) const { return _accel_ef; }
// Methods
virtual void update(void) = 0;
// Euler angles (radians)
float roll;
float pitch;
float yaw;
// integer Euler angles (Degrees * 100)
int32_t roll_sensor;
int32_t pitch_sensor;
int32_t yaw_sensor;
// return a smoothed and corrected gyro vector
virtual const Vector3f get_gyro(void) const = 0;
// return the current estimate of the gyro drift
virtual const Vector3f &get_gyro_drift(void) const = 0;
// reset the current attitude, used on new IMU calibration
virtual void reset(bool recover_eulers=false) = 0;
// how often our attitude representation has gone out of range
uint8_t renorm_range_count;
// how often our attitude representation has blown up completely
uint8_t renorm_blowup_count;
// return the average size of the roll/pitch error estimate
// since last call
virtual float get_error_rp(void) = 0;
// return the average size of the yaw error estimate
// since last call
virtual float get_error_yaw(void) = 0;
// return a DCM rotation matrix representing our current
// attitude
virtual const Matrix3f &get_dcm_matrix(void) const = 0;
// get our current position, either from GPS or via
// dead-reckoning. Return true if a position is available,
// otherwise false. This only updates the lat and lng fields
// of the Location
virtual bool get_position(struct Location &loc) {
if (!_gps || _gps->status() <= GPS::NO_FIX) {
return false;
}
loc.lat = _gps->latitude;
loc.lng = _gps->longitude;
return true;
}
// get our projected position, based on our GPS position plus
// heading and ground speed
bool get_projected_position(struct Location &loc);
// return the estimated lag in our position due to GPS lag
float get_position_lag(void) const;
// return a wind estimation vector, in m/s
virtual Vector3f wind_estimate(void) {
return Vector3f(0,0,0);
}
// return an airspeed estimate if available. return true
// if we have an estimate
virtual bool airspeed_estimate(float *airspeed_ret);
// return a true airspeed estimate (navigation airspeed) if
// available. return true if we have an estimate
bool airspeed_estimate_true(float *airspeed_ret) {
if (!airspeed_estimate(airspeed_ret)) {
return false;
}
*airspeed_ret *= get_EAS2TAS();
return true;
}
// get apparent to true airspeed ratio
float get_EAS2TAS(void) const {
if (_airspeed) {
return _airspeed->get_EAS2TAS();
}
return 1.0f;
}
// return true if airspeed comes from an airspeed sensor, as
// opposed to an IMU estimate
bool airspeed_sensor_enabled(void) const {
return _airspeed != NULL && _airspeed->use();
}
// return a ground vector estimate in meters/second, in North/East order
Vector2f groundspeed_vector(void);
// return true if we will use compass for yaw
virtual bool use_compass(void) const { return _compass && _compass->use_for_yaw(); }
// return true if yaw has been initialised
bool yaw_initialised(void) const {
return _flags.have_initial_yaw;
}
// set the fast gains flag
void set_fast_gains(bool setting) {
_flags.fast_ground_gains = setting;
}
// set the correct centrifugal flag
// allows arducopter to disable corrections when disarmed
void set_correct_centrifugal(bool setting) {
_flags.correct_centrifugal = setting;
}
// get trim
const Vector3f &get_trim() const { return _trim.get(); }
// set trim
virtual void set_trim(Vector3f new_trim);
// add_trim - adjust the roll and pitch trim up to a total of 10 degrees
virtual void add_trim(float roll_in_radians, float pitch_in_radians, bool save_to_eeprom = true);
// for holding parameters
static const struct AP_Param::GroupInfo var_info[];
// these are public for ArduCopter
AP_Float _kp_yaw;
AP_Float _kp;
AP_Float gps_gain;
protected:
// settable parameters
AP_Float beta;
AP_Int8 _gps_use;
AP_Int8 _wind_max;
AP_Int8 _board_orientation;
AP_Int8 _gps_minsats;
// flags structure
struct ahrs_flags {
uint8_t have_initial_yaw : 1; // whether the yaw value has been intialised with a reference
uint8_t fast_ground_gains : 1; // should we raise the gain on the accelerometers for faster convergence, used when disarmed for ArduCopter
uint8_t fly_forward : 1; // 1 if we can assume the aircraft will be flying forward on its X axis
uint8_t correct_centrifugal : 1; // 1 if we should correct for centrifugal forces (allows arducopter to turn this off when motors are disarmed)
uint8_t wind_estimation : 1; // 1 if we should do wind estimation
} _flags;
// pointer to compass object, if available
Compass * _compass;
// pointer to airspeed object, if available
AP_Airspeed * _airspeed;
// time in microseconds of last compass update
uint32_t _compass_last_update;
// note: we use ref-to-pointer here so that our caller can change the GPS without our noticing
// IMU under us without our noticing.
AP_InertialSensor *_ins;
GPS *&_gps;
// a vector to capture the difference between the controller and body frames
AP_Vector3f _trim;
// the limit of the gyro drift claimed by the sensors, in
// radians/s/s
float _gyro_drift_limit;
// accelerometer values in the earth frame in m/s/s
Vector3f _accel_ef;
// Declare filter states for HPF and LPF used by complementary
// filter in AP_AHRS::groundspeed_vector
Vector2f _lp; // ground vector low-pass filter
Vector2f _hp; // ground vector high-pass filter
Vector2f _lastGndVelADS; // previous HPF input
};
#include <AP_AHRS_DCM.h>
#include <AP_AHRS_MPU6000.h>
#include <AP_AHRS_HIL.h>
#endif // __AP_AHRS_H__