replicant-frameworks_native/services/sensorservice/Fusion.h
Mathias Agopian 3301542828 use quaternions instead of MRPs
also use correct time propagation equation
disable the fused sensors when gyro is not present since
they were unusable in practice.

Change-Id: Iad797425784e67dc6c5690e97c71c583418cc5b5
2012-06-27 17:07:55 -07:00

86 lines
2.2 KiB
C++

/*
* 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;
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
* 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();
void handleGyro(const vec3_t& w, float dT);
status_t handleAcc(const vec3_t& a);
status_t handleMag(const vec3_t& m);
vec4_t getAttitude() const;
vec3_t getBias() const;
mat33_t getRotationMatrix() const;
bool hasEstimate() const;
private:
mat<mat33_t, 2, 2> Phi;
vec3_t Ba, Bm;
uint32_t mInitState;
float mGyroRate;
vec<vec3_t, 3> mData;
size_t mCount[3];
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);
bool checkState(const vec3_t& v);
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);
};
}; // namespace android
#endif // ANDROID_FUSION_H