altb_pmic / Mbed 2 deprecated Test_ekf

Testing ekf implementation for Quadro_1.

Dependencies:   mbed Eigen

EKF_RP.cpp@4:e50e18eac72b, 2019-10-20 (annotated)

Committer:
pmic
Date:
Sun Oct 20 08:27:25 2019 +0000
Revision:
4:e50e18eac72b
Parent:
1:6b803652d032
Child:
5:676cbc33c81b
Commit before set double for test purposes.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
pmic 0:a0e9705be9c4 1 #include "EKF_RP.h"
pmic 0:a0e9705be9c4 2
pmic 0:a0e9705be9c4 3 using namespace std;
pmic 0:a0e9705be9c4 4 using namespace Eigen;
pmic 0:a0e9705be9c4 5
pmic 0:a0e9705be9c4 6 EKF_RP::EKF_RP(float Ts)
pmic 0:a0e9705be9c4 7 {
pmic 0:a0e9705be9c4 8 this->Ts = Ts;
pmic 0:a0e9705be9c4 9 /* [n_gyro; n_b_g; n_v] */
pmic 0:a0e9705be9c4 10 var_fx << 1000, 1000, 20, 20, 10, 10;
pmic 0:a0e9705be9c4 11 /* [n_acc] */
pmic 0:a0e9705be9c4 12 var_gy << 40, 40;
pmic 0:a0e9705be9c4 13 rho = 5000;
pmic 0:a0e9705be9c4 14 kv = 0.5; /* k1/m */
pmic 0:a0e9705be9c4 15 g = 9.81;
pmic 0:a0e9705be9c4 16 reset();
pmic 0:a0e9705be9c4 17 }
pmic 0:a0e9705be9c4 18
pmic 0:a0e9705be9c4 19 EKF_RP::~EKF_RP() {}
pmic 0:a0e9705be9c4 20
pmic 0:a0e9705be9c4 21 void EKF_RP::reset()
pmic 0:a0e9705be9c4 22 {
pmic 0:a0e9705be9c4 23 u.setZero();
pmic 0:a0e9705be9c4 24 y.setZero();
pmic 0:a0e9705be9c4 25 x.setZero();
pmic 4:e50e18eac72b 26 update_angles();
pmic 4:e50e18eac72b 27 calc_F();
pmic 4:e50e18eac72b 28 calc_H();
pmic 0:a0e9705be9c4 29 initialize_Q();
pmic 0:a0e9705be9c4 30 initialize_R();
pmic 0:a0e9705be9c4 31 P = Q;
pmic 0:a0e9705be9c4 32 K.setZero();
pmic 0:a0e9705be9c4 33 I.setIdentity();
pmic 0:a0e9705be9c4 34 }
pmic 0:a0e9705be9c4 35
pmic 4:e50e18eac72b 36 float EKF_RP::get_est_state(uint8_t i)
pmic 4:e50e18eac72b 37 {
pmic 4:e50e18eac72b 38 /* x = [ang; b_g; v] */
pmic 4:e50e18eac72b 39 return x(i);
pmic 4:e50e18eac72b 40 }
pmic 4:e50e18eac72b 41
pmic 0:a0e9705be9c4 42 void EKF_RP::update(float gyro_x, float gyro_y, float accel_x, float accel_y)
pmic 0:a0e9705be9c4 43 {
pmic 4:e50e18eac72b 44 u << gyro_x, gyro_y;
pmic 4:e50e18eac72b 45 y << accel_x, accel_y;
pmic 4:e50e18eac72b 46 update_angles();
pmic 0:a0e9705be9c4 47
pmic 4:e50e18eac72b 48 calc_F();
pmic 4:e50e18eac72b 49 calc_H(); /* H remains constant */
pmic 4:e50e18eac72b 50 calc_Q();
pmic 0:a0e9705be9c4 51
pmic 4:e50e18eac72b 52 x = fxd();
pmic 0:a0e9705be9c4 53 // P = F * P * F.transpose() + Q;
pmic 0:a0e9705be9c4 54
pmic 4:e50e18eac72b 55 K = P * H.transpose() * ( H * P * H.transpose() + R ).inverse();
pmic 0:a0e9705be9c4 56
pmic 0:a0e9705be9c4 57 // x = x + K * (y - gy());
pmic 0:a0e9705be9c4 58 // P = (I - K * H) * P;
pmic 0:a0e9705be9c4 59 }
pmic 0:a0e9705be9c4 60
pmic 4:e50e18eac72b 61 float EKF_RP::read_Q(uint8_t i, uint8_t j)
pmic 0:a0e9705be9c4 62 {
pmic 4:e50e18eac72b 63 return Q(i,j);
pmic 0:a0e9705be9c4 64 }
pmic 0:a0e9705be9c4 65
pmic 0:a0e9705be9c4 66 void EKF_RP::update_angles()
pmic 0:a0e9705be9c4 67 {
pmic 1:6b803652d032 68 s1 = sin(x(0));
pmic 1:6b803652d032 69 c1 = cos(x(0));
pmic 1:6b803652d032 70 s2 = sin(x(1));
pmic 1:6b803652d032 71 c2 = cos(x(1));
pmic 0:a0e9705be9c4 72 }
pmic 0:a0e9705be9c4 73
pmic 4:e50e18eac72b 74 void EKF_RP::calc_F()
pmic 0:a0e9705be9c4 75 {
pmic 0:a0e9705be9c4 76 F << (Ts*c1*s2*(u(1) - x(3)))/c2 + 1, -(Ts*s1*(u(1) - x(3)))/(s2*s2 - 1), -Ts, -(Ts*s1*s2)/c2, 0, 0,
pmic 0:a0e9705be9c4 77 -Ts*s1*(u(1) - x(3)), 1, 0, -Ts*c1, 0, 0,
pmic 0:a0e9705be9c4 78 0, 0, 1, 0, 0, 0,
pmic 0:a0e9705be9c4 79 0, 0, 0, 1, 0, 0,
pmic 0:a0e9705be9c4 80 0, Ts*c2*g, 0, 0, 1 - Ts*kv, 0,
pmic 0:a0e9705be9c4 81 -Ts*c1*c2*g, Ts*g*s1*s2, 0, 0, 0, 1 - Ts*kv;
pmic 0:a0e9705be9c4 82 }
pmic 0:a0e9705be9c4 83
pmic 4:e50e18eac72b 84 void EKF_RP::calc_H()
pmic 0:a0e9705be9c4 85 {
pmic 0:a0e9705be9c4 86 H << 0, 0, 0, 0, -kv, 0,
pmic 0:a0e9705be9c4 87 0, 0, 0, 0, 0, -kv;
pmic 0:a0e9705be9c4 88 }
pmic 0:a0e9705be9c4 89
pmic 0:a0e9705be9c4 90 void EKF_RP::initialize_R()
pmic 0:a0e9705be9c4 91 {
pmic 0:a0e9705be9c4 92 R << rho*var_gy(0)/Ts, 0,
pmic 0:a0e9705be9c4 93 0, rho*var_gy(1)/Ts;
pmic 0:a0e9705be9c4 94 }
pmic 0:a0e9705be9c4 95
pmic 0:a0e9705be9c4 96 void EKF_RP::initialize_Q()
pmic 0:a0e9705be9c4 97 {
pmic 4:e50e18eac72b 98 Q << Ts*(var_fx(0) + s1*s1*s2*s2*var_fx(1)/(c2*c2)), Ts*c1*s1*s2*var_fx(1)/c2, 0, 0, 0, 0,
pmic 4:e50e18eac72b 99 Ts*c1*s1*s2*var_fx(1)/c2, Ts*c1*c1*var_fx(1), 0, 0, 0, 0,
pmic 4:e50e18eac72b 100 0, 0, Ts*var_fx(2), 0, 0, 0,
pmic 4:e50e18eac72b 101 0, 0, 0, Ts*var_fx(3), 0, 0,
pmic 4:e50e18eac72b 102 0, 0, 0, 0, Ts*var_fx(4), 0,
pmic 4:e50e18eac72b 103 0, 0, 0, 0, 0, Ts*var_fx(5);
pmic 0:a0e9705be9c4 104 }
pmic 0:a0e9705be9c4 105
pmic 4:e50e18eac72b 106 void EKF_RP::calc_Q()
pmic 0:a0e9705be9c4 107 {
pmic 4:e50e18eac72b 108 Q(0,0) = Ts*(var_fx(0) + s1*s1*s2*s2*var_fx(1)/(c2*c2));
pmic 0:a0e9705be9c4 109 Q(0,1) = Ts*c1*s1*s2*var_fx(1)/c2;
pmic 0:a0e9705be9c4 110 Q(1,0) = Q(0,1);
pmic 0:a0e9705be9c4 111 Q(1,1) = Ts*c1*c1*var_fx(1);
pmic 0:a0e9705be9c4 112 }
pmic 0:a0e9705be9c4 113
pmic 0:a0e9705be9c4 114 Matrix <float, 6, 1> EKF_RP::fxd()
pmic 0:a0e9705be9c4 115 {
pmic 0:a0e9705be9c4 116 Matrix <float, 6, 1> retval;
pmic 0:a0e9705be9c4 117 retval << x(0) + Ts*(u(0) - x(2) + (s1*s2*(u(1) - x(3)))/c2),
pmic 0:a0e9705be9c4 118 x(1) + Ts*c1*(u(1) - x(3)),
pmic 0:a0e9705be9c4 119 x(2),
pmic 0:a0e9705be9c4 120 x(3),
pmic 0:a0e9705be9c4 121 x(4) + Ts*(g*s2 - kv*x(4)),
pmic 0:a0e9705be9c4 122 x(5) - Ts*(kv*x(5) + c2*g*s1);
pmic 0:a0e9705be9c4 123 return retval;
pmic 0:a0e9705be9c4 124 }
pmic 0:a0e9705be9c4 125
pmic 0:a0e9705be9c4 126 Matrix <float, 2, 1> EKF_RP::gy()
pmic 0:a0e9705be9c4 127 {
pmic 0:a0e9705be9c4 128 Matrix <float, 2, 1> retval;
pmic 0:a0e9705be9c4 129 retval << -kv*x(4),
pmic 0:a0e9705be9c4 130 -kv*x(5);
pmic 0:a0e9705be9c4 131 return retval;
pmic 0:a0e9705be9c4 132 }
pmic 0:a0e9705be9c4 133