dark0707
/
px4-firmware
forked from Archive/PX4-Autopilot
1
0
Fork 0
Code Pull Requests Activity

EKF: Add derivation for for dual antenna yaw observations

This commit is contained in:
Paul Riseborough 2018-08-28 07:17:31 +10:00 committed by Paul Riseborough
parent 342c3ab202
commit af60e6bbc8
2 changed files with 61 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
EKF/matlab/scripts/Inertial Nav EKF/GenerateNavFilterEquations.m
View File

@ -415,6 +415,29 @@ fix_c_code('calcH_YAW312.c');
clear all;
reset(symengine);
%% derive equations for fusion of dual antenna yaw measurement
load('StatePrediction.mat');
syms ant_yaw real; % yaw angle of antenna array axis wrt X body axis
% define antenna vector in body frame
ant_vec_bf = [cos(ant_yaw);sin(ant_yaw);0];
% rotate into earth frame
ant_vec_ef = Tbn * ant_vec_bf;
% Calculate the yaw angle from the projection
angMeas = atan(ant_vec_ef(2)/ant_vec_ef(1));
H_YAWGPS = jacobian(angMeas,stateVector); % measurement Jacobian
H_YAWGPS = simplify(H_YAWGPS);
ccode(H_YAWGPS,'file','calcH_YAWGPS.c');
fix_c_code('calcH_YAWGPS.c');
% reset workspace
clear all;
reset(symengine);
%% derive equations for fusion of declination
load('StatePrediction.mat');

38
EKF/matlab/scripts/Inertial Nav EKF/calcH_YAWGPS.c Normal file
View File

@ -0,0 +1,38 @@
t2 = sin(ant_yaw);
t3 = cos(ant_yaw);
t4 = q0*q3*2.0;
t5 = q0*q0;
t6 = q1*q1;
t7 = q2*q2;
t8 = q3*q3;
t9 = q1*q2*2.0;
t10 = t5+t6-t7-t8;
t11 = t3*t10;
t12 = t4+t9;
t13 = t3*t12;
t14 = t5-t6+t7-t8;
t15 = t2*t14;
t16 = t13+t15;
t17 = t4-t9;
t19 = t2*t17;
t20 = t11-t19;
t18 = 1.0/(t20*t20);
t21 = t16*t16;
t22 = 1.0/pow(t11-t19][2.0);
t23 = q1*t3*2.0;
t24 = q2*t2*2.0;
t25 = t23+t24;
t26 = 1.0/t20;
t27 = q1*t2*2.0;
t28 = t21*t22;
t29 = t28+1.0;
t30 = 1.0/t29;
t31 = q0*t3*2.0;
t32 = t31-q3*t2*2.0;
t33 = q3*t3*2.0;
t34 = q0*t2*2.0;
t35 = t33+t34;
A0[0][0] = (t35/(t11-t2*(t4-q1*q2*2.0))-t16*t18*t32)/(t18*t21+1.0);
A0[0][1] = -t30*(t26*(t27-q2*t3*2.0)+t16*t22*t25);
A0[0][2] = t30*(t25*t26-t16*t22*(t27-q2*t3*2.0));
A0[0][3] = t30*(t26*t32+t16*t22*t35);