ardupilot/libraries/AP_InertialNav/AP_InertialNav.h

128 lines
4.0 KiB
C++

#pragma once
#include <AP_AHRS/AP_AHRS.h>
#include <AP_InertialSensor/AP_InertialSensor.h> // ArduPilot Mega IMU Library
#include <AP_Baro/AP_Baro.h> // ArduPilot Mega Barometer Library
#include <AP_Buffer/AP_Buffer.h> // FIFO buffer library
#include <AP_NavEKF/AP_Nav_Common.h> // definitions shared by inertial and ekf nav filters
/*
* AP_InertialNav blends accelerometer data with gps and barometer data to improve altitude and position hold.
*
* Most of the functions have to be called at 100Hz. (see defines above)
*
* The accelerometer values are integrated over time to approximate velocity and position.
* The inaccurcy of these estimates grows over time due to noisy sensor data.
* To improve the accuracy, baro and gps readings are used:
* An error value is calculated as the difference between the sensor's measurement and the last position estimation.
* This value is weighted with a gain factor and incorporated into the new estimation
*
* Special thanks to Tony Lambregts (FAA) for advice which contributed to the development of this filter.
*
*/
class AP_InertialNav
{
public:
// Constructor
AP_InertialNav() {}
/**
* update - updates velocity and position estimates using latest info from accelerometers
* augmented with gps and baro readings
*
* @param dt : time since last update in seconds
*/
virtual void update(float dt) = 0;
/**
* get_filter_status : returns filter status as a series of flags
*/
virtual nav_filter_status get_filter_status() const = 0;
/**
* get_origin - returns the inertial navigation origin in lat/lon/alt
*
* @return origin Location
*/
virtual struct Location get_origin() const = 0;
//
// XY Axis specific methods
//
/**
* get_position - returns the current position relative to the home location in cm.
*
* @return
*/
virtual const Vector3f& get_position() const = 0;
/**
* get_llh - updates the provided location with the latest calculated location including absolute altitude
* returns true on success (i.e. the EKF knows it's latest position), false on failure
*/
virtual bool get_location(struct Location &loc) const = 0;
/**
* get_latitude - returns the latitude of the current position estimation in 100 nano degrees (i.e. degree value multiplied by 10,000,000)
* @return
*/
virtual int32_t get_latitude() const = 0;
/**
* get_longitude - returns the longitude of the current position estimation in 100 nano degrees (i.e. degree value multiplied by 10,000,000)
* @return
*/
virtual int32_t get_longitude() const = 0;
/**
* get_velocity - returns the current velocity in cm/s
*
* @return velocity vector:
* .x : latitude velocity in cm/s
* .y : longitude velocity in cm/s
* .z : vertical velocity in cm/s
*/
virtual const Vector3f& get_velocity() const = 0;
/**
* get_velocity_xy - returns the current horizontal velocity in cm/s
*
* @returns the current horizontal velocity in cm/s
*/
virtual float get_velocity_xy() const = 0;
//
// Z Axis methods
//
/**
* get_altitude - get latest altitude estimate in cm above the
* reference position
* @return
*/
virtual float get_altitude() const = 0;
/**
* get_hgt_ctrl_limit - get maximum height to be observed by the control loops in cm and a validity flag
* this is used to limit height during optical flow navigation
* it will return invalid when no limiting is required
* @return
*/
virtual bool get_hgt_ctrl_limit(float& limit) const = 0;
/**
* get_velocity_z - returns the current climbrate.
*
* @see get_velocity().z
*
* @return climbrate in cm/s (positive up)
*/
virtual float get_velocity_z() const = 0;
};
#if AP_AHRS_NAVEKF_AVAILABLE
#include "AP_InertialNav_NavEKF.h"
#endif