blob: 602779f5390e8b7dc8be3da0a3ce8f78b09cec4c [file] [log] [blame]
/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ANDROID_FUSION_H
#define ANDROID_FUSION_H
#include <utils/Errors.h>
#include "quat.h"
#include "mat.h"
#include "vec.h"
namespace android {
typedef mat<float, 3, 4> mat34_t;
enum FUSION_MODE{
FUSION_9AXIS, // use accel gyro mag
FUSION_NOMAG, // use accel gyro (game rotation, gravity)
FUSION_NOGYRO, // use accel mag (geomag rotation)
NUM_FUSION_MODE
};
class Fusion {
/*
* the state vector is made of two sub-vector containing respectively:
* - modified Rodrigues parameters
* - the estimated gyro bias
*/
quat_t x0;
vec3_t x1;
/*
* the predicated covariance matrix is made of 4 3x3 sub-matrices and it is
* semi-definite positive.
*
* P = | P00 P10 | = | P00 P10 |
* | P01 P11 | | P10t P11 |
*
* Since P01 = transpose(P10), the code below never calculates or
* stores P01.
*/
mat<mat33_t, 2, 2> P;
/*
* the process noise covariance matrix
*/
mat<mat33_t, 2, 2> GQGt;
public:
Fusion();
void init(int mode = FUSION_9AXIS);
void handleGyro(const vec3_t& w, float dT);
status_t handleAcc(const vec3_t& a, float dT);
status_t handleMag(const vec3_t& m);
vec4_t getAttitude() const;
vec3_t getBias() const;
mat33_t getRotationMatrix() const;
bool hasEstimate() const;
private:
struct Parameter {
float gyroVar;
float gyroBiasVar;
float accStdev;
float magStdev;
} mParam;
mat<mat33_t, 2, 2> Phi;
vec3_t Ba, Bm;
uint32_t mInitState;
float mGyroRate;
vec<vec3_t, 3> mData;
size_t mCount[3];
int mMode;
enum { ACC=0x1, MAG=0x2, GYRO=0x4 };
bool checkInitComplete(int, const vec3_t& w, float d = 0);
void initFusion(const vec4_t& q0, float dT);
void checkState();
void predict(const vec3_t& w, float dT);
void update(const vec3_t& z, const vec3_t& Bi, float sigma);
static mat34_t getF(const vec4_t& p);
static vec3_t getOrthogonal(const vec3_t &v);
};
}; // namespace android
#endif // ANDROID_FUSION_H