% Measurement: noisy GPS (standard deviation = 3 meters) measurement_noise = 3; measurements = true_pos + measurement_noise * randn(size(t));
K_history = zeros(50, 1); P_history = zeros(50, 1);
%% Kalman Filter for 1D Position Tracking clear; clc; close all; % Simulation parameters dt = 0.1; % Time step (seconds) T = 10; % Total time (seconds) t = 0:dt:T; % Time vector N = length(t); % Number of steps --- Kalman Filter For Beginners With MATLAB Examples BEST
%% Visualizing Kalman Gain and Uncertainty clear; clc; dt = 0.1; F = [1 dt; 0 1]; H = [1 0]; R = 9; % Measurement noise variance Q = [0.1 0; 0 0.1];
Developed by Rudolf E. Kálmán in 1960, the Kalman filter is a recursive algorithm that estimates the state of a dynamic system from a series of incomplete and noisy measurements. It is widely used in robotics, navigation, economics, and signal processing. For beginners, the math can seem daunting, but the core idea is simple: % Measurement: noisy GPS (standard deviation = 3
%% Initialize Kalman Filter % State vector: [position; velocity] x_est = [0; 10]; % Initial guess (position, velocity) P = [1 0; 0 1]; % Initial uncertainty covariance
subplot(2,1,2); plot(t, true_vel, 'g-', 'LineWidth', 2); hold on; plot(t, est_vel, 'b-', 'LineWidth', 1.5); xlabel('Time (s)'); ylabel('Velocity (m/s)'); title('Velocity Estimate'); legend('True', 'Kalman Estimate'); grid on; For beginners, the math can seem daunting, but
% Update (using a dummy measurement) S = H * P_pred * H' + R; K = P_pred * H' / S; P = (eye(2) - K * H) * P_pred;
The filter starts with an initial guess (0 m position, 10 m/s velocity). As each noisy GPS reading arrives, the Kalman filter computes the optimal blend between the model prediction and the measurement. Notice how the position estimate (blue line) is much smoother than the noisy measurements (red dots), and the velocity converges to the true value (10 m/s). Example 2: Visualizing the Kalman Gain This example shows how the filter becomes more confident over time.