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Dependencies: Eigen
ekf.cpp
- Committer:
- altb2
- Date:
- 2019-05-03
- Revision:
- 4:3c21fb0c9e84
- Child:
- 5:eee47600b772
File content as of revision 4:3c21fb0c9e84:
#include "ekf.h"
using namespace std;
ekf::ekf(float Ts) : x(6,1,0.0),x_km(6,1,0.0),P(6,0.01),Q(6),R(2,0.025),F(6,6,0.0),H(2,6,0.0),K(6,2,0.0),E(6)
{
g = 9.81;
tau_g = 10;
itau_g = 1/tau_g;
k1 = 0.25;
m = 1.1;
kdm = k1/m;
this->Ts = Ts;
F.put_entry(1,3,-1);
F.put_entry(2,4,-1);
F.put_entry(3,3,-1/tau_g);
F.put_entry(4,4,-1/tau_g);
F.put_entry(5,2,-g);
F.put_entry(6,1,g);
F.put_entry(5,5,-k1/m);
F.put_entry(6,6,-k1/m);
H.put_entry(1,5,-kdm);
H.put_entry(2,6,-kdm);
F.scale(Ts);
Q.mcopy(&(F/=F)); // Q=A*A'
Q.scale(.1);
F.mcopy(&(F+E));
}
ekf::~ekf(void) {
printf("EKF is being deleted\r\n");
}
void ekf::dgl(matrix *Z)
{
x_km.a[0][0]= x.a[0][0]+Ts*(Z->a[0][0]-x.a[2][0]+tan(x.a[1][0])*sin(x.a[0][0])*(Z->a[1][0]-x.a[3][0]));
x_km.a[1][0]= x.a[1][0]+Ts*(cos(x.a[0][0])*(Z->a[1][0]-x.a[3][0]));
x_km.a[2][0]= x.a[2][0]+Ts*(-itau_g*x.a[2][0]);
x_km.a[3][0]= x.a[3][0]+Ts*(-itau_g*x.a[3][0]);
x_km.a[4][0]= x.a[4][0]+Ts*(-g*sin(x.a[1][0])-kdm*x.a[4][0]);
x_km.a[5][0]= x.a[5][0]+Ts*(g*cos(x.a[1][0])*sin(x.a[0][0])-kdm*x.a[5][0]);
}
void ekf::loop(matrix *Z)
{
// F_km1 is constant
dgl(Z); // here x_km is calculated
P.mcopy(&(((F*P)/=F)+Q)); //P_km = F_km1*P_km*F_km1'+Q_k
matrix dum1(2);
dum1.mcopy(&(((H*P)/=H)+R));
K.mcopy(&((P/=H)*dum1.inv_2x2())); // K_k=(P_km*H_k')*inv(H_k*P_km*H_k'+R_k); % Kalman-Gain
// x_k = x_km + K_k*(Z(r,[4 5])'-copter3D_calc_h_ekf(x_km,kin));
matrix dum2(2,1,0.0);
dum2.put_entry(1,1,Z->a[3][0]+kdm*x_km.a[4][0]);
dum2.put_entry(2,1,Z->a[4][0]+kdm*x_km.a[5][0]); // calculates Z-h h is -k/m*...
x_km += (K*dum2);
x.mcopy(&x_km);
// P_km = (eye(6)-K_k*H_k)*P_km; % Kovar
P.mcopy(&((E-(K*H))*P));
}
float ekf::get_est_state(uint8_t i)
{
return x_km.a[i-1][0];
}
//
void ekf::display_matrix(char c)
{
switch(c) {
case 'H':
printf("H=\r\n");
H.printout();
break;
case 'P':
printf("P=\r\n");
P.printout();
break;
case 'Q':
printf("Q=\r\n");
Q.printout();
break;
case 'R':
printf("R=\r\n");
R.printout();
break;
case 'F':
printf("F=\r\n");
F.printout();
break;
case 'K':
printf("K=\r\n");
K.printout();
break;
default:
break;
}
}