生成考虑随机输入噪声的粒子滤波算法的程序
时间: 2024-02-13 14:01:21 浏览: 231
下面是一个考虑随机输入噪声的粒子滤波算法的 MATLAB 程序,供参考:
```matlab
function [Xo, particles] = particle_filter(input, y0, B, R, Q, N, k, u_Q, ResampleStrategy)
% input: 系统输入
% y0: 观测值
% B: 输入噪声系数
% R: 观测噪声协方差矩阵
% Q: 系统噪声协方差矩阵
% N: 粒子数量
% k: 时间步长
% u_Q: 输入噪声方差
% ResampleStrategy: 重采样策略
% 初始化粒子集合
particles = randn(N, 1);
% 进行状态估计
for ii = 1:N
% 对每个粒子进行状态转移
particles(ii) = process_equation(particles(ii), k) + B * (sqrt(u_Q) * randn + gamrnd(1, 1)) + sqrt(Q) * randn + gamrnd(1, 1);
% 计算粒子对应的观测值
ypart = detection_equation(particles(ii), k);
% 计算粒子的权重
vhat = y0 - ypart;
weight(ii) = 1 / (det(R)^(1/2)) * exp(-1/2 * vhat' * inv(R) * vhat) + 1e-99;
end
% 对权重进行归一化处理
weights = weight / sum(weight);
% 对粒子集合进行重采样
particles = resample(particles, weights, ResampleStrategy);
% 计算状态估计值
Xo = mean(particles);
end
% 状态转移函数
function x_next = process_equation(x, k)
% TODO: 根据实际问题定义状态转移函数
end
% 观测函数
function y = detection_equation(x, k)
% TODO: 根据实际问题定义观测函数
end
% 重采样函数
function particles = resample(particles, weights, ResampleStrategy)
switch ResampleStrategy
case 1 % 随机重采样
outIndex = randomR(weights);
case 2 % 残差重采样
outIndex = residualR(weights);
case 3 % 系统重采样
outIndex = systematicR(weights);
case 4 % 多项式重采样
outIndex = multinomialR(weights);
end
% 使用重采样后的粒子集合进行状态估计
particles = particles(outIndex);
end
% 随机重采样
function outIndex = randomR(weights)
N = length(weights);
outIndex = zeros(1, N);
for ii = 1:N
u = rand;
acc = weights(1);
jj = 1;
while u > acc
jj = jj + 1;
acc = acc + weights(jj);
end
outIndex(ii) = jj;
end
end
% 残差重采样
function outIndex = residualR(weights)
N = length(weights);
outIndex = zeros(1, N);
residuals = N * weights - 1;
for ii = 1:N
u = rand;
acc = residuals(1);
jj = 1;
while u > acc
jj = jj + 1;
acc = acc + residuals(jj);
end
outIndex(ii) = jj;
residuals(jj) = residuals(jj) - 1;
end
end
% 系统重采样
function outIndex = systematicR(weights)
N = length(weights);
outIndex = zeros(1, N);
u = rand / N;
acc = weights(1);
jj = 1;
for ii = 1:N
while u > acc
jj = jj + 1;
acc = acc + weights(jj);
end
outIndex(ii) = jj;
u = u + 1 / N;
end
end
% 多项式重采样
function outIndex = multinomialR(weights)
N = length(weights);
outIndex = zeros(1, N);
for ii = 1:N
outIndex(ii) = find(rand < cumsum(weights), 1);
end
end
```
需要注意的是,该程序中的 process_equation 和 detection_equation 函数需要根据实际问题进行定义。此外,粒子滤波算法中的重采样策略也需要根据具体问题进行选择和调整。
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