source: flair-src/trunk/lib/FlairFilter/src/AhrsComplementaryFilter.cpp

Last change on this file was 223, checked in by Sanahuja Guillaume, 4 years ago

add delta time to io_data

File size: 5.8 KB
RevLine 
[24]1// %flair:license{
2// This file is part of the Flair framework distributed under the
3// CECILL-C License, Version 1.0.
4// %flair:license}
5
6//  created:    2014/04/28
7//  filename:   AhrsComplementaryFilter.cpp
8//
9//  authors:    Augustin Manecy (RT-MaG Toolbox author, augustin.manecy@gmail.com)
10//              API changes by Guillaume Sanahuja to fit the Flair framework
11//
12//  version:    $Id: $
13//
14//  purpose:    Class defining an Ahrs complementary filter
15//
16//
17/*********************************************************************/
18
19#include "AhrsComplementaryFilter.h"
20#include <Imu.h>
21#include <DoubleSpinBox.h>
[198]22#include <Vector3DSpinBox.h>
[24]23#include <GridLayout.h>
24#include <ImuData.h>
25#include <AhrsData.h>
26#include <math.h>
27
28#define G 9.81
29
30using std::string;
31using namespace flair::core;
32using namespace flair::gui;
33using namespace flair::sensor;
34
35namespace flair { namespace filter {
36
[223]37AhrsComplementaryFilter::AhrsComplementaryFilter(const Imu* parent,string name): Ahrs(parent,name) {
[24]38
[198]39  QHat.q0=1;
40  QHat.q1=0;
41  QHat.q2=0;
42  QHat.q3=0;
43  BHat.x=0;
44  BHat.y=0;
45  BHat.z=0;
[24]46
[198]47  ka[0]=new DoubleSpinBox(parent->GetLayout()->NewRow(),"ka[0]:",0.,10,0.1,2,0.5);
48  ka[1]=new DoubleSpinBox(parent->GetLayout()->LastRowLastCol(),"ka[1]:",0.,10,0.1,2,0.5);
49  ka[2]=new DoubleSpinBox(parent->GetLayout()->LastRowLastCol(),"ka[2]:",0.,10.,0.1,2,0.);
[24]50
[198]51  kb[0]=new DoubleSpinBox(parent->GetLayout()->NewRow(),"kb[0]:",0.,10,0.1,2,0.01);
52  kb[1]=new DoubleSpinBox(parent->GetLayout()->LastRowLastCol(),"kb[1]:",0.,10,0.1,2,0.01);
53  kb[2]=new DoubleSpinBox(parent->GetLayout()->LastRowLastCol(),"kb[2]:",0.,10,0.1,2,0.01);
54
55  //put km to [0,0,0] to disable magnetometers
56  km[0]=new DoubleSpinBox(parent->GetLayout()->NewRow(),"km[0]:",0.,50,0.1,2,0.01);
57  km[1]=new DoubleSpinBox(parent->GetLayout()->LastRowLastCol(),"km[1]:",0.,50,0.1,2,0.01);
58  km[2]=new DoubleSpinBox(parent->GetLayout()->LastRowLastCol(),"km[2]:",0.,50,0.1,2,0.01);
[157]59 
[198]60  magRef=new Vector3DSpinBox(parent->GetLayout()->NewRow(),"ref magnetic field (uT)",
61                                 0, 100, 1,
62                                 3,Vector3Df(20.5324,.2367,43.6682)); //Compiegne, France
[157]63  SetIsReady(true);
[24]64}
65
66AhrsComplementaryFilter::~AhrsComplementaryFilter() {
67
68}
69
70void AhrsComplementaryFilter::UpdateFrom(const io_data *data) {
71    ImuData *input=(ImuData*)data;
72    float delta_t;
73    AhrsData* ahrsData;
74    GetDatas(&ahrsData);
[167]75    Vector3Df rawAcc,rawMag,rawGyr;
[24]76    input->GetRawAccMagAndGyr(rawAcc,rawMag,rawGyr);
77
[223]78    delta_t=(float)(data->DataDeltaTime())/1000000000.;
[24]79
[167]80    Vector3Df aBar,aHat,aTilde;
81    Vector3Df mBar,mHat,mTilde;
[197]82    Vector3Df alpha,dBHat,omegaHat,magRef;
[24]83    Quaternion dQHat;
84
85    //float ka[3]={0.5,0.5,0};
86    //float kb[3]={0.01,0.01,0.01};
[197]87    //float k_m[3]= {0,0,0};
[198]88    magRef=this->magRef->Value();
[24]89
[223]90    if(delta_t!=0) {
[197]91        // CORRECTION FROM ACCELEROMETER
[24]92        aBar = rawAcc;
93
94        // estimation of IMU vector using QHat (estimated quaternion): aHat = Inv(QHat) * g
95        /*
96          Inv(QHat) = [q0 -q1 -q2 -q3]'
97          Inv(QHat)*g = [1-2(q2^2+q3^2)     2(q1q2+q0q3)     2(q1q3-q0q2)]     [0]
98                         [  2(q1q2-q0q3)   1-2(q1^2+q3^2))    2(q2q3+q0q1)]  *  [0]
99                         [  2(q1q3+q0q2)     2(q2q3-q0q1)   1-2(q1^2+q2^2)]     [g]
100        */
101        aHat.x = -2*G*(QHat.q1*QHat.q3 - QHat.q0*QHat.q2);
102        aHat.y = -2*G*(QHat.q2*QHat.q3 + QHat.q0*QHat.q1);
103        aHat.z = -G*(1-2.0*(QHat.q1*QHat.q1 + QHat.q2*QHat.q2));
104
105        // cross(aHat, aBar)
106        aTilde=CrossProduct(aHat, aBar);
107
[197]108       
109        // CORRECTION FROM MAGNETOMETER
110        // estimation of IMU vector using QHat (estimated quaternion): mHat = Inv(QHat) * m_ref = Inv(QHat) * magRef
[24]111        /*
112          Inv(QHat) = [q0 -q1 -q2 -q3]'
[197]113          Inv(QHat)*g = [1-2(q2^2+q3^2)     2(q1q2+q0q3)     2(q1q3-q0q2)]     [magRef.x]
114                         [  2(q1q2-q0q3)   1-2(q1^2+q3^2))    2(q2q3+q0q1)]  *  [magRef.x]
115                         [  2(q1q3+q0q2)     2(q2q3-q0q1)   1-2(q1^2+q2^2)]     [magRef.x]
[24]116        */
[197]117        mBar=rawMag;
118       
119        mHat.x = (1-2.0*(QHat.q2*QHat.q2 + QHat.q3*QHat.q3))*magRef.x+2.0*(QHat.q1*QHat.q2+QHat.q0*QHat.q3)*magRef.y+2.0*(QHat.q1*QHat.q3-QHat.q0*QHat.q2)*magRef.z;
120        mHat.y = 2.0*(QHat.q1*QHat.q2 - QHat.q0*QHat.q3)*magRef.x+(1-2.0*(QHat.q1*QHat.q1 + QHat.q3*QHat.q3))*magRef.y+2.0*(QHat.q2*QHat.q3 + QHat.q0*QHat.q1)*magRef.z;
121        mHat.z = 2.0*(QHat.q1*QHat.q3+QHat.q0*QHat.q2)*magRef.x+2.0*(QHat.q2*QHat.q3 - QHat.q0*QHat.q1)*magRef.y+(1-2.0*(QHat.q1*QHat.q1 + QHat.q2*QHat.q2))*magRef.z;
122       
123       
[24]124        // compute the error between mHat and mTilde
125        mTilde=CrossProduct(mHat, mBar);
126
127        // Compute the debiased rotation speed
128        omegaHat = rawGyr - BHat;
129
130        // calculate the correction to apply to the quaternion
[197]131        alpha.x = (ka[0]->Value()*aTilde.x)/(G*G) + (km[0]->Value()*mTilde.x)/(magRef.GetNorm()*magRef.GetNorm());
132        alpha.y = (ka[1]->Value()*aTilde.y)/(G*G) + (km[1]->Value()*mTilde.y)/(magRef.GetNorm()*magRef.GetNorm());
133        alpha.z = (ka[2]->Value()*aTilde.z)/(G*G) + (km[2]->Value()*mTilde.z)/(magRef.GetNorm()*magRef.GetNorm());
[24]134
135        // Bias derivative
136        dBHat.x = kb[0]->Value() * alpha.x;
137        dBHat.y = kb[1]->Value() * alpha.y;
138        dBHat.z = kb[2]->Value() * alpha.z;
139
140        // Bias integration
141        BHat = BHat+dBHat*delta_t;
142
143        // Quaternion derivative: dQHat = 0.5*(QHat*Q_corr)
144        // Q_corr: Corrected pure rotation quaternion for integration
145        dQHat=QHat.GetDerivative(omegaHat - alpha);
146
147        // Quaternion integration
148        QHat = QHat +dQHat*delta_t;     // delta_t: sampling period [s]
149
150        QHat.Normalize();
151
152        ahrsData->SetQuaternionAndAngularRates(QHat,rawGyr - BHat);
153
[223]154    } 
[24]155
156    ahrsData->SetDataTime(data->DataTime());
157    ProcessUpdate(ahrsData);
158}
159
160} // end namespace filter
161} // end namespace flair
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