altb_pmic / Mbed 2 deprecated Test_ekf

Testing ekf implementation for Quadro_1.

Dependencies:   mbed Eigen

EKF_RPY.cpp@9:be2e1d2f683d, 2019-10-20 (annotated)

Committer:
pmic
Date:
Sun Oct 20 16:30:34 2019 +0000
Revision:
9:be2e1d2f683d
Parent:
8:a72cd6356bab
Child:
12:180e09c4ea26
Change parametrization, so it is close to the exciting ekf and nummerically balanced.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
pmic 0:a0e9705be9c4 1 #include "EKF_RPY.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_RPY::EKF_RPY(float Ts, float mx0, float my0, float mz0)
pmic 0:a0e9705be9c4 7 {
pmic 0:a0e9705be9c4 8 this->Ts = Ts;
pmic 7:bcbcc23983de 9 /* [n_gyro; n_v; n_b_g] */
pmic 9:be2e1d2f683d 10 var_fx << 0.01f, 0.01f, 0.01f, 0.0001f, 0.0001f, 0.0001f, 0.0001f, 0.0001f;
pmic 0:a0e9705be9c4 11 /* [n_acc; n_mag] */
pmic 9:be2e1d2f683d 12 var_gy << 45.0f, 45.0f, 0.1f, 0.1f;
pmic 9:be2e1d2f683d 13 rho = 0.5f;
pmic 7:bcbcc23983de 14 kv = 0.5f; /* k1/m */
pmic 7:bcbcc23983de 15 g = 9.81f;
pmic 0:a0e9705be9c4 16 m0 << mx0, my0, mz0;
pmic 0:a0e9705be9c4 17 reset();
pmic 0:a0e9705be9c4 18 }
pmic 0:a0e9705be9c4 19
pmic 0:a0e9705be9c4 20 EKF_RPY::~EKF_RPY() {}
pmic 0:a0e9705be9c4 21
pmic 0:a0e9705be9c4 22 void EKF_RPY::reset()
pmic 0:a0e9705be9c4 23 {
pmic 0:a0e9705be9c4 24 u.setZero();
pmic 0:a0e9705be9c4 25 y.setZero();
pmic 0:a0e9705be9c4 26 x.setZero();
pmic 7:bcbcc23983de 27 update_angles();
pmic 7:bcbcc23983de 28 calc_F();
pmic 7:bcbcc23983de 29 calc_H();
pmic 0:a0e9705be9c4 30 initialize_Q();
pmic 0:a0e9705be9c4 31 initialize_R();
pmic 7:bcbcc23983de 32 P = Q;
pmic 0:a0e9705be9c4 33 K.setZero();
pmic 7:bcbcc23983de 34 I.setIdentity();
pmic 7:bcbcc23983de 35 }
pmic 7:bcbcc23983de 36
pmic 7:bcbcc23983de 37 float EKF_RPY::get_est_state(uint8_t i)
pmic 7:bcbcc23983de 38 {
pmic 7:bcbcc23983de 39 /* x = [ang; v; b_g] = [0: phi
pmic 7:bcbcc23983de 40 1: theta
pmic 7:bcbcc23983de 41 2: psi
pmic 7:bcbcc23983de 42 3: b_gx
pmic 7:bcbcc23983de 43 4: b_gy
pmic 7:bcbcc23983de 44 5: b_gz
pmic 7:bcbcc23983de 45 6: vx
pmic 7:bcbcc23983de 46 7: vy] */
pmic 7:bcbcc23983de 47 return x(i);
pmic 0:a0e9705be9c4 48 }
pmic 0:a0e9705be9c4 49
pmic 0:a0e9705be9c4 50 void EKF_RPY::update(float gyro_x, float gyro_y, float gyro_z, float accel_x, float accel_y, float magnet_x, float magnet_y)
pmic 7:bcbcc23983de 51 {
pmic 0:a0e9705be9c4 52 u << gyro_x, gyro_y, gyro_z;
pmic 0:a0e9705be9c4 53 y << accel_x, accel_y, magnet_x, magnet_y;
pmic 7:bcbcc23983de 54 update_angles();
pmic 0:a0e9705be9c4 55
pmic 7:bcbcc23983de 56 calc_F();
pmic 7:bcbcc23983de 57 calc_H();
pmic 7:bcbcc23983de 58 calc_Q();
pmic 0:a0e9705be9c4 59
pmic 0:a0e9705be9c4 60 x = fxd();
pmic 0:a0e9705be9c4 61 P = F * P * F.transpose() + Q;
pmic 0:a0e9705be9c4 62
pmic 7:bcbcc23983de 63 K = P * H.transpose() * ( H * P * H.transpose() + R ).inverse();
pmic 0:a0e9705be9c4 64
pmic 0:a0e9705be9c4 65 x = x + K * (y - gy());
pmic 0:a0e9705be9c4 66 P = (I - K * H) * P;
pmic 0:a0e9705be9c4 67 }
pmic 0:a0e9705be9c4 68
pmic 0:a0e9705be9c4 69 void EKF_RPY::update_angles()
pmic 0:a0e9705be9c4 70 {
pmic 7:bcbcc23983de 71 s1 = sinf(x(0));
pmic 7:bcbcc23983de 72 c1 = cosf(x(0));
pmic 7:bcbcc23983de 73 s2 = sinf(x(1));
pmic 7:bcbcc23983de 74 c2 = cosf(x(1));
pmic 7:bcbcc23983de 75 s3 = sinf(x(2));
pmic 7:bcbcc23983de 76 c3 = cosf(x(2));
pmic 0:a0e9705be9c4 77 }
pmic 0:a0e9705be9c4 78
pmic 7:bcbcc23983de 79 void EKF_RPY::calc_F()
pmic 7:bcbcc23983de 80 {
pmic 7:bcbcc23983de 81 F << Ts*(c1*s2*(u(1) - x(6)) - s1*s2*(u(2) - x(7)))/c2 + 1.0f, Ts*(c1*(u(2) - x(7)) + s1*(u(1) - x(6)))/(c2*c2), 0.0f, 0.0f, 0.0f, -Ts, -Ts*s1*s2/c2, -Ts*c1*s2/c2,
pmic 7:bcbcc23983de 82 -Ts*(c1*(u(2) - x(7)) + s1*(u(1) - x(6))), 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, -Ts*c1, Ts*s1,
pmic 7:bcbcc23983de 83 Ts*(c1*(u(1) - x(6)) - s1*(u(2) - x(7)))/c2, Ts*(c1*(u(2) - x(7)) + s1*(u(1) - x(6)))*s2/(c2*c2), 1.0f, 0.0f, 0.0f, 0.0f, -Ts*s1/c2, -Ts*c1/c2,
pmic 7:bcbcc23983de 84 0.0f, Ts*c2*g, 0.0f, 1.0f - Ts*kv, Ts*(u(2) - x(7)), 0.0f, 0.0f, -Ts*x(4),
pmic 7:bcbcc23983de 85 -Ts*c1*c2*g, Ts*g*s1*s2, 0.0f, -Ts*(u(2) - x(7)), 1.0f - Ts*kv, 0.0f, 0.0f, Ts*x(3),
pmic 7:bcbcc23983de 86 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f,
pmic 7:bcbcc23983de 87 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f,
pmic 7:bcbcc23983de 88 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f;
pmic 7:bcbcc23983de 89 }
pmic 0:a0e9705be9c4 90
pmic 7:bcbcc23983de 91 void EKF_RPY::calc_H()
pmic 7:bcbcc23983de 92 {
pmic 7:bcbcc23983de 93 H << 0.0f, 0.0f, 0.0f, -kv, u(2) - x(7), 0.0f, 0.0f, -x(4),
pmic 7:bcbcc23983de 94 0.0f, 0.0f, 0.0f, x(7) - u(2), -kv, 0.0f, 0.0f, x(3),
pmic 7:bcbcc23983de 95 0.0f, - c2*m0(2) - c3*m0(0)*s2 - m0(1)*s2*s3, c2*(c3*m0(1) - m0(0)*s3), 0.0f, 0.0f, 0.0f, 0.0f, 0.0f,
pmic 7:bcbcc23983de 96 m0(0)*(s1*s3 + c1*c3*s2) - m0(1)*(c3*s1 - c1*s2*s3) + c1*c2*m0(2), s1*(c2*c3*m0(0) - m0(2)*s2 + c2*m0(1)*s3), - m0(0)*(c1*c3 + s1*s2*s3) - m0(1)*(c1*s3 - c3*s1*s2), 0.0f, 0.0f, 0.0f, 0.0f, 0.0f;
pmic 7:bcbcc23983de 97 }
pmic 0:a0e9705be9c4 98
pmic 0:a0e9705be9c4 99 void EKF_RPY::initialize_R()
pmic 7:bcbcc23983de 100 {
pmic 7:bcbcc23983de 101 R << rho*var_gy(0)/Ts, 0.0f, 0.0f, 0.0f,
pmic 7:bcbcc23983de 102 0.0f, rho*var_gy(1)/Ts, 0.0f, 0.0f,
pmic 7:bcbcc23983de 103 0.0f, 0.0f, rho*var_gy(2)/Ts, 0.0f,
pmic 7:bcbcc23983de 104 0.0f, 0.0f, 0.0f, rho*var_gy(3)/Ts;
pmic 7:bcbcc23983de 105 }
pmic 0:a0e9705be9c4 106
pmic 0:a0e9705be9c4 107 void EKF_RPY::initialize_Q()
pmic 7:bcbcc23983de 108 {
pmic 7:bcbcc23983de 109 Q << Ts*(var_fx(0) + (c1*c1*var_fx(2) + s1*s1*var_fx(1))*s2*s2/(c2*c2)), Ts*(var_fx(1) - var_fx(2))*c1*s1*s2/c2, Ts*(c1*c1*var_fx(2) + s1*s1*var_fx(1))*s2/(c2*c2), 0.0f, 0.0f, 0.0f, 0.0f, 0.0f,
pmic 7:bcbcc23983de 110 Ts*(var_fx(1) - var_fx(2))*c1*s1*s2/c2, Ts*(var_fx(1)*c1*c1 + var_fx(2)*s1*s1), Ts*(var_fx(1) - var_fx(2))*c1*s1/c2, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f,
pmic 7:bcbcc23983de 111 Ts*(c1*c1*var_fx(2) + s1*s1*var_fx(1))*s2/(c2*c2), Ts*(var_fx(1) - var_fx(2))*c1*s1/c2, Ts*(c1*c1*var_fx(2) + s1*s1*var_fx(1))/(c2*c2), 0.0f, 0.0f, 0.0f, 0.0f, 0.0f,
pmic 7:bcbcc23983de 112 0.0f, 0.0f, 0.0f, Ts*var_fx(3), 0.0f, 0.0f, 0.0f, 0.0f,
pmic 7:bcbcc23983de 113 0.0f, 0.0f, 0.0f, 0.0f, Ts*var_fx(4), 0.0f, 0.0f, 0.0f,
pmic 7:bcbcc23983de 114 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, Ts*var_fx(5), 0.0f, 0.0f,
pmic 7:bcbcc23983de 115 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, Ts*var_fx(6), 0.0f,
pmic 7:bcbcc23983de 116 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, Ts*var_fx(7);
pmic 7:bcbcc23983de 117 }
pmic 0:a0e9705be9c4 118
pmic 7:bcbcc23983de 119 void EKF_RPY::calc_Q()
pmic 7:bcbcc23983de 120 {
pmic 7:bcbcc23983de 121 Q(0,0) = Ts*(var_fx(0) + (c1*c1*var_fx(2) + s1*s1*var_fx(1))*s2*s2/(c2*c2));
pmic 7:bcbcc23983de 122 Q(0,1) = Ts*(var_fx(1) - var_fx(2))*c1*s1*s2/c2;
pmic 7:bcbcc23983de 123 Q(0,2) = Ts*(c1*c1*var_fx(2) + s1*s1*var_fx(1))*s2/(c2*c2);
pmic 0:a0e9705be9c4 124 Q(1,0) = Q(0,1);
pmic 7:bcbcc23983de 125 Q(1,1) = Ts*(var_fx(1)*c1*c1 + var_fx(2)*s1*s1);
pmic 7:bcbcc23983de 126 Q(1,2) = Ts*(var_fx(1) - var_fx(2))*c1*s1/c2;
pmic 0:a0e9705be9c4 127 Q(2,0) = Q(0,2);
pmic 0:a0e9705be9c4 128 Q(2,1) = Q(1,2);
pmic 7:bcbcc23983de 129 Q(2,2) = Ts*(c1*c1*var_fx(2) + s1*s1*var_fx(1))/(c2*c2);
pmic 7:bcbcc23983de 130 }
pmic 0:a0e9705be9c4 131
pmic 7:bcbcc23983de 132 Matrix <float, 8, 1> EKF_RPY::fxd()
pmic 0:a0e9705be9c4 133 {
pmic 7:bcbcc23983de 134 Matrix <float, 8, 1> retval;
pmic 0:a0e9705be9c4 135 retval << x(0) + Ts*(u(0) - x(5) + (c1*s2*(u(2) - x(7)))/c2 + (s1*s2*(u(1) - x(6)))/c2),
pmic 0:a0e9705be9c4 136 x(1) + Ts*(c1*(u(1) - x(6)) - s1*(u(2) - x(7))),
pmic 0:a0e9705be9c4 137 x(2) + Ts*((c1*(u(2) - x(7)))/c2 + (s1*(u(1) - x(6)))/c2),
pmic 0:a0e9705be9c4 138 x(3) + Ts*(g*s2 - kv*x(3) + x(4)*(u(2) - x(7))),
pmic 0:a0e9705be9c4 139 x(4) - Ts*(kv*x(4) + x(3)*(u(2) - x(7)) + c2*g*s1),
pmic 0:a0e9705be9c4 140 x(5),
pmic 0:a0e9705be9c4 141 x(6),
pmic 7:bcbcc23983de 142 x(7);
pmic 0:a0e9705be9c4 143 return retval;
pmic 0:a0e9705be9c4 144 }
pmic 0:a0e9705be9c4 145
pmic 0:a0e9705be9c4 146 Matrix <float, 4, 1> EKF_RPY::gy()
pmic 0:a0e9705be9c4 147 {
pmic 0:a0e9705be9c4 148 Matrix <float, 4, 1> retval;
pmic 7:bcbcc23983de 149 retval << x(4)*(u(2) - x(7)) - kv*x(3),
pmic 7:bcbcc23983de 150 - kv*x(4) - x(3)*(u(2) - x(7)),
pmic 7:bcbcc23983de 151 - m0(2)*s2 + c2*c3*m0(0) + c2*m0(1)*s3,
pmic 7:bcbcc23983de 152 - m0(0)*(c1*s3 - c3*s1*s2) + m0(1)*(c1*c3 + s1*s2*s3) + c2*m0(2)*s1;
pmic 0:a0e9705be9c4 153 return retval;
pmic 0:a0e9705be9c4 154 }
pmic 0:a0e9705be9c4 155