MATLAB卡尔曼滤波仿真教程与示例

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资源摘要信息:"kalman.zip_matlab_truthu6x" 卡尔曼滤波是一种高效的递归滤波器,它能够从一系列的含有噪声的测量中估计动态系统的状态。该滤波器在1960年由鲁道夫·E·卡尔曼提出,并迅速在众多领域得到了应用,如信号处理、自动控制、航天技术等。该算法的关键优势在于其能够在存在不确定性的情况下,提供一个最优的状态估计。 卡尔曼滤波器的工作原理是通过建立系统的状态空间模型,并利用一系列的线性代数方程来实现状态的更新。状态空间模型通常包括状态方程和观测方程。状态方程描述了系统的内在动态,即下一时刻的状态是如何由当前状态按照一定的模型演变而来的。观测方程则描述了观测值与系统状态之间的关系。 对于本资源,它包含了MATLAB实现的卡尔曼滤波示例脚本文件 "kalman.m"。MATLAB是一种广泛使用的数学计算和仿真软件,尤其适合于工程和科研领域。在该脚本文件中,可能包含了以下知识点: 1. 卡尔曼滤波器的设计与实现:包括状态空间模型的构建、初始条件的设定、系统的动态噪声和观测噪声的假设。 2. 状态估计的更新过程:包括预测步骤和更新步骤。预测步骤是根据当前状态估计和系统动态方程来预测下一时刻的状态。更新步骤则是根据新的观测值来修正预测状态,得到更为准确的状态估计。 3. MATLAB脚本编写:涉及变量的初始化、矩阵和向量操作、循环和条件语句的使用等。 4. 滤波效果的可视化:通过MATLAB的绘图功能展示滤波前后的数据对比,以及状态估计随时间变化的图形。 5. 参数调优:如何选择合适的卡尔曼滤波器参数来获得最佳的滤波效果,例如过程噪声协方差矩阵Q、观测噪声协方差矩阵R和初始状态估计协方差矩阵P。 6. 误差分析:如何评估滤波效果,包括计算均方根误差(RMSE)等指标。 7. 针对新手的指导:如果资源中包含了注释或者附加的文档,那么它可能还会提供一些入门级的指导,帮助新手理解卡尔曼滤波的基本概念和如何在MATLAB中实现。 通过使用 "kalman.zip_matlab_truthu6x" 资源,新手可以学习到如何使用MATLAB软件进行卡尔曼滤波的仿真,以及如何对系统的状态进行有效估计。这种实践对于理解卡尔曼滤波器的理论知识和实际应用都具有重要的意义。通过实际操作,新手可以加深对于动态系统建模、状态估计以及最优滤波器设计等概念的理解。

帮我给每一行代码添加注释 class DeepKalmanFilter(nn.Module): def __init__(self, config): super(DeepKalmanFilter, self).__init__() self.emitter = Emitter(config.z_dim, config.emit_hidden_dim, config.obs_dim) self.transition = Transition(config.z_dim, config.trans_hidden_dim) self.posterior = Posterior( config.z_dim, config.post_hidden_dim, config.obs_dim ) self.z_q_0 = nn.Parameter(torch.zeros(config.z_dim)) self.emit_log_sigma = nn.Parameter(config.emit_log_sigma * torch.ones(config.obs_dim)) self.config = config @staticmethod def reparametrization(mu, sig): return mu + torch.randn_like(sig) * sig @staticmethod def kl_div(mu0, sig0, mu1, sig1): return -0.5 * torch.sum(1 - 2 * sig1.log() + 2 * sig0.log() - (mu1 - mu0).pow(2) / sig1.pow(2) - (sig0 / sig1).pow(2)) def loss(self, obs): time_step = obs.size(1) batch_size = obs.size(0) overshoot_len = self.config.overshooting kl = torch.Tensor([0]).to(self.config.device) reconstruction = torch.Tensor([0]).to(self.config.device) emit_sig = self.emit_log_sigma.exp() for s in range(self.config.sampling_num): z_q_t = self.z_q_0.expand((batch_size, self.config.z_dim)) for t in range(time_step): trans_loc, trans_sig = self.transition(z_q_t) post_loc, post_sig = self.posterior(trans_loc, trans_sig, obs[:, t]) z_q_t = self.reparametrization(post_loc, post_sig) emit_loc = self.emitter(z_q_t) reconstruction += ((emit_loc - obs[:, t]).pow(2).sum(dim=0) / 2 / emit_sig + self.emit_log_sigma * batch_size / 2).sum() if t > 0: over_loc, over_sig = self.transition(overshooting[:overshoot_len - 1]) over_loc = torch.cat([trans_loc.unsqueeze(0), over_loc], dim=0) over_sig = torch.cat([trans_sig.unsqueeze(0), over_sig], dim=0) else: over_loc = trans_loc.unsqueeze(0) over_sig = trans_sig.unsqueeze(0) overshooting = self.reparametrization(over_loc, over_sig) kl = kl + self.kl_div(post_loc.expand_as(over_loc), post_sig.expand_as(over_sig), over_loc, over_sig) / min(t + 1, self.config.overshooting) reconstruction = reconstruction / self.config.sampling_num kl = kl / self.config.sampling_num return reconstruction, kl

2023-02-22 上传

解释一段python代码 class KalmanFilter(object): def init(self, dim_x, dim_z, dim_u=0): if dim_x < 1: raise ValueError('dim_x must be 1 or greater') if dim_z < 1: raise ValueError('dim_z must be 1 or greater') if dim_u < 0: raise ValueError('dim_u must be 0 or greater') self.dim_x = dim_x self.dim_z = dim_z self.dim_u = dim_u self.x = zeros((dim_x, 1)) # state self.P = eye(dim_x) # uncertainty covariance self.Q = eye(dim_x) # process uncertainty self.B = None # control transition matrix self.F = eye(dim_x) # state transition matrix self.H = zeros((dim_z, dim_x)) # Measurement function self.R = eye(dim_z) # state uncertainty self._alpha_sq = 1. # fading memory control self.M = np.zeros((dim_z, dim_z)) # process-measurement cross correlation self.z = np.array([[None]*self.dim_z]).T # gain and residual are computed during the innovation step. We # save them so that in case you want to inspect them for various # purposes self.K = np.zeros((dim_x, dim_z)) # kalman gain self.y = zeros((dim_z, 1)) self.S = np.zeros((dim_z, dim_z)) # system uncertainty self.SI = np.zeros((dim_z, dim_z)) # inverse system uncertainty # identity matrix. Do not alter this. self._I = np.eye(dim_x) # these will always be a copy of x,P after predict() is called self.x_prior = self.x.copy() self.P_prior = self.P.copy() # these will always be a copy of x,P after update() is called self.x_post = self.x.copy() self.P_post = self.P.copy() # Only computed only if requested via property self._log_likelihood = log(sys.float_info.min) self._likelihood = sys.float_info.min self._mahalanobis = None self.inv = np.linalg.inv

2023-06-07 上传