add Kalman filter

master
Gabriele Gilardi 2020-06-17 15:08:08 +09:00
rodzic 1f8e47a34f
commit 8fef296eba
2 zmienionych plików z 201 dodań i 162 usunięć

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@ -31,153 +31,153 @@
# -------------------------------------------------------
import numpy as np
# import numpy as np
measurements = [ 1., 2., 3. ]
dt = 1.
# measurements = [ 1., 2., 3. ]
# dt = 1.
# Initial state (location and velocity)
x = np.array([[ 0. ],
[ 0. ]])
# Initial uncertainty
P = np.array([[ 1000., 0. ],
[ 0., 1000. ]])
# External motion
U = np.array([[ 0. ],
[ 0. ]])
# Next state function
F = np.array([[ 1., dt ],
[ 0., 1. ]])
# Measurement function
H = np.array([[ 1., 0. ]])
# Measurement uncertainty
R = np.array([[ 1. ]])
# Identity matrix
I = np.eye(2)
# # Initial state (location and velocity)
# x = np.array([[ 0. ],
# [ 0. ]])
# # Initial uncertainty
# P = np.array([[ 1000., 0. ],
# [ 0., 1000. ]])
# # External motion
# U = np.array([[ 0. ],
# [ 0. ]])
# # Next state function
# F = np.array([[ 1., dt ],
# [ 0., 1. ]])
# # Measurement function
# H = np.array([[ 1., 0. ]])
# # Measurement uncertainty
# R = np.array([[ 1. ]])
# # Identity matrix
# I = np.eye(2)
def filter(x, P):
# def filter(x, P):
step = 0
for z in (measurements):
step += 1
print("step = ", step, " meas. = ", z)
# step = 0
# for z in (measurements):
# step += 1
# print("step = ", step, " meas. = ", z)
# Measurement
Htra = H.T
S = H.dot(P.dot(Htra)) + R
Sinv = np.linalg.inv(S)
K = P.dot(Htra.dot(Sinv))
y = z - H.dot(x)
xp = x +K.dot(y)
Pp = P - K.dot(H.dot(P))
# # Measurement
# Htra = H.T
# S = H.dot(P.dot(Htra)) + R
# Sinv = np.linalg.inv(S)
# K = P.dot(Htra.dot(Sinv))
# y = z - H.dot(x)
# xp = x +K.dot(y)
# Pp = P - K.dot(H.dot(P))
# Prediction
x = F.dot(xp) + U
Ftra = F.T
P = F.dot(Pp.dot(Ftra))
# # Prediction
# x = F.dot(xp) + U
# Ftra = F.T
# P = F.dot(Pp.dot(Ftra))
print('x =')
print(x)
print('P =')
print(P)
# print('x =')
# print(x)
# print('P =')
# print(P)
filter(x, P)
# filter(x, P)
# # -------------------------------------------------------
# import numpy as np
import numpy as np
# # x0 = 4.
# # y0 = 12.
# # measurements = np.array([[ 5., 10. ],
# # [ 6., 8. ],
# # [ 7., 6. ],
# # [ 8., 4. ],
# # [ 9., 2. ],
# # [ 10., 0. ]])
# # x0 = -4.
# # y0 = 8.
# # measurements = np.array([[ 1., 4. ],
# # [ 6., 0. ],
# # [ 11., -4. ],
# # [ 16., -8. ]])
# # x0 = 1.
# # y0 = 19.
# # measurements = np.array([[ 1., 17. ],
# # [ 1., 15. ],
# # [ 1., 13. ],
# # [ 1., 11. ]])
x0 = 4.
y0 = 12.
measurements = np.array([[ 5., 10. ],
[ 6., 8. ],
[ 7., 6. ],
[ 8., 4. ],
[ 9., 2. ],
[ 10., 0. ]])
# x0 = -4.
# y0 = 8.
# measurements = np.array([[ 1., 4. ],
# [ 6., 0. ],
# [ 11., -4. ],
# [ 16., -8. ]])
# x0 = 1.
# y0 = 19.
# measurements = np.array([[ 1., 17. ],
# [ 1., 15. ],
# [ 1., 13. ],
# [ 1., 11. ]])
# x0 = 1.
# y0 = 19.
# measurements = np.array([[ 2., 17. ],
# [ 0., 15. ],
# [ 2., 13. ],
# [ 0., 11. ]])
# # Time step
# dt = 0.1
# # Initial state (location and velocity)
# x = np.array([[ x0 ],
# [ y0 ],
# [ 0. ],
# [ 0. ]])
# # Initial uncertainty
# P = np.array([[ 0., 0., 0., 0. ],
# [ 0., 0., 0., 0. ],
# [ 0., 0., 1000., 0. ],
# [ 0., 0., 0., 1000. ]])
# # External motion
# U = np.array([[ 0. ],
# [ 0. ],
# [ 0. ],
# [ 0. ]])
# # Next state function
# F = np.array([[ 1., 0., dt, 0. ],
# [ 0., 1., 0., dt ],
# [ 0., 0., 1., 0. ],
# [ 0., 0., 0., 1. ]])
# # Measurement function
# H = np.array([[ 1., 0., 0., 0. ],
# [ 0., 1., 0., 0. ]])
# # Measurement uncertainty
# R = np.array([[ 0.1, 0. ],
# [ 0. , 0.1 ]])
# # Measurement vector
# z = np.zeros((2,1))
# Time step
dt = 0.1
# Initial state (location and velocity)
x = np.array([[ x0 ],
[ y0 ],
[ 0. ],
[ 0. ]])
# Initial uncertainty
P = np.array([[ 0., 0., 0., 0. ],
[ 0., 0., 0., 0. ],
[ 0., 0., 1000., 0. ],
[ 0., 0., 0., 1000. ]])
# External motion
U = np.array([[ 0. ],
[ 0. ],
[ 0. ],
[ 0. ]])
# Next state function
F = np.array([[ 1., 0., dt, 0. ],
[ 0., 1., 0., dt ],
[ 0., 0., 1., 0. ],
[ 0., 0., 0., 1. ]])
# Measurement function
H = np.array([[ 1., 0., 0., 0. ],
[ 0., 1., 0., 0. ]])
# Measurement uncertainty
R = np.array([[ 0.1, 0. ],
[ 0. , 0.1 ]])
# Measurement vector
z = np.zeros((2,1))
# def filter(x, P):
def filter(x, P):
# for n in range(len(measurements)):
for n in range(len(measurements)):
# z[0][0] = measurements[n][0]
# z[1][0] = measurements[n][1]
z[0][0] = measurements[n][0]
z[1][0] = measurements[n][1]
# # Prediction
# xp = F.dot(x) + U
# Ftra = F.T
# Pp = F.dot(P.dot(Ftra))
# Prediction
xp = F.dot(x) + U
Ftra = F.T
Pp = F.dot(P.dot(Ftra))
# # Measurement
# Htra = H.T
# S = H.dot(Pp.dot(Htra)) + R
# Sinv = np.linalg.inv(S)
# K = Pp.dot(Htra.dot(Sinv))
# y = z - H.dot(xp)
# x = xp +K.dot(y)
# P = Pp - K.dot(H.dot(Pp))
# # print(z)
# # print('x = ')
# # print(x)
# # print('P = ')
# # print(P)
# # print(' ')
# Measurement
Htra = H.T
S = H.dot(Pp.dot(Htra)) + R
Sinv = np.linalg.inv(S)
K = Pp.dot(Htra.dot(Sinv))
y = z - H.dot(xp)
x = xp +K.dot(y)
P = Pp - K.dot(H.dot(Pp))
# print(z)
# print('x = ')
# print(x)
# print('P = ')
# print(P)
# print(' ')
# return x, P
return x, P
# x_final, P_final = filter(x, P)
# print('x = ')
# print(x_final)
# print('P = ')
# print(P_final)
x_final, P_final = filter(x, P)
print('x = ')
print(x_final)
print('P = ')
print(P_final)

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@ -1,45 +1,92 @@
"""
- generalize to N and M
M = 1
N = 2
correction = update = measurement
prediction = motion
X (n_states, 1) State vector
P (n_states, n_states) Covariance matrix of X
F (n_states, n_states) State transition matrix
U (n_states, 1) Input/control/drift vector
Z (n_meas, 1) Measurament vector
H (n_meas, n_states) Measurament matrix
R (n_meas, n_meas) Covariance matrix of Z
S (n_meas, n_meas) Covariance matrix (?)
K (n_states, m) Kalman gain
Q (n_states, n_states) Covariance matrix (?)
Data (n_meas, n_samples) Measurements
Fext (n_states, n_samples) External driver
X0 (n_states, 1) Initial state vector
P0 (n_states, n_states) Initial covariance matrix of X
"""
import numpy as np
dt = 1.
measurements = np.array([ 1., 2., 3., 4., 5., 6., 7., 8, 9, 10])
class KalmanFilter:
# State vector
# (N, 1)
x = np.array([[ 0. ],
[ 0. ]])
def __init__(self, F, H, Q, R):
"""
"""
self.F = F
self.Q = Q
self.H = H
self.R = R
# Prediction uncertainty (covariance matrix of x)
# (N, N)
P = np.array([[ 1000., 0. ],
[ 0., 1000. ]])
def prediction(self, X, P, U):
X = self.F @ X + U
P = self.F @ P @ self.F.T + self.Q
return X, P
def update(self, X, P, Z):
"""
"""
S = self.H @ P @ self.H.T + self.R
K = P @ self.H.T @ np.linalg.inv(S)
X = X + K @ (Z - self.H @ X)
P = P - K @ self.H @ P
return X, P
def applyFilter(self, Data, Fext, X0, P0):
"""
"""
pass
# Measurements
data = np.array([[5., 6., 7., 8., 9., 10.],
[10., 8., 6., 4., 2., 0.]])
# Initial state vector
X0 = np.array([[4. ],
[12.],
[0. ],
[0. ]])
# Initial covariance matrix of X
P0 = np.array([[0., 0., 0., 0.],
[0., 0., 0., 0.],
[0., 0., 1000., 0.],
[0., 0., 0., 1000.]])
# External motion
# (N, 1)
U = np.array([[ 0. ],
[ 0. ]])
Fext = np.zeros_like(data)
# Update matrix (state transition matrix)
# (N, N)
F = np.array([[ 1., dt ],
[ 0., 1. ]])
# Measurement function (extraction matrix)
# (M, N)
H = np.array([[ 1., 0. ]])
# Measurement uncertainty/noise (covariance matrix of z)
# (M, M)
R = np.array([[ 1. ]])
# z = measurament vector
# (M, 1)
# Next state function
dt = 0.1
F = np.array([[ 1., 0., dt, 0. ],
[ 0., 1., 0., dt ],
[ 0., 0., 1., 0. ],
[ 0., 0., 0., 1. ]])
# Measurement function
H = np.array([[ 1., 0., 0., 0. ],
[ 0., 1., 0., 0. ]])
# Measurement uncertainty
R = np.array([[ 0.1, 0. ],
[ 0. , 0.1 ]])
def filter(x, P):
@ -48,16 +95,8 @@ def filter(x, P):
step += 1
print("step = ", step, " meas. = ", z)
# Measurement
S = H @ P @ H.T + R # (M, M)
K = P @ H.T @ np.linalg.inv(S) # (N, M)
y = z - H @ x
xp = x + K @ y
Pp = P - K @ H @ P
# Update
# Prediction
x = F @ xp + U
P = F @ Pp @ F.T
print('x =')
print(x)