多目标跟踪关联匹配算法(匈牙利算法和KM算法原理讲解和代码实现)
目录 多目标跟踪关联匹配算法
0、多目标跟踪算法流程
1、卡尔曼滤波
卡尔曼滤波算法的过程很简单,如下图所示。最核心的两个步骤就是预测和更新(下图的 correct)。
1.1 预测
对应代码如下:
def predict(self, mean, covariance):
"""Run Kalman filter prediction step.
Parameters
----------
mean : ndarray
The 8 dimensional mean vector of the object state at the previous
time step.
covariance : ndarray
The 8x8 dimensional covariance matrix of the object state at the
previous time step.
Returns
-------
(ndarray, ndarray)
Returns the mean vector and covariance matrix of the predicted
state. Unobserved velocities are initialized to 0 mean.
"""
std_pos = [
self._std_weight_position * mean[0],
self._std_weight_position * mean[1],
1 * mean[2],
self._std_weight_position * mean[3]]
std_vel = [
self._std_weight_velocity * mean[0],
self._std_weight_velocity * mean[1],
0.1 * mean[2],
self._std_weight_velocity * mean[3]]
motion_cov = np.diag(np.square(np.r_[std_pos, std_vel])) # 噪声矩阵Q
mean = np.dot(self._motion_mat, mean) # x'=Fx
covariance = np.linalg.multi_dot((
self._motion_mat, covariance, self._motion_mat.T)) + motion_cov # P' = FPF(T) + Q
return mean, covariance
关于 F 和 Q 的初始化是在 init() 函数中进行的。F 称为 状态转移矩阵,其初始化为
def __init__(self):
ndim, dt = 4, 1.
# Create Kalman filter model matrices.
self._motion_mat = np.eye(2 * ndim, 2 * ndim) # 状态转移矩阵 F
for i in range(ndim):
self._motion_mat[i, ndim + i] = dt
self._update_mat = np.eye(ndim, 2 * ndim) # 测量矩阵 H
# Motion and observation uncertainty are chosen relative to the current
# state estimate. These weights control the amount of uncertainty in