Design Case Studies    

Time-Varying Kalman Filter

The time-varying Kalman filter is a generalization of the steady-state filter for time-varying systems or LTI systems with nonstationary noise covariance. Given the plant state and measurement equations

the time-varying Kalman filter is given by the recursions

Measurement update

Time update

with and as defined in Discrete Kalman Filter, and in the following.

For simplicity, we have dropped the subscripts indicating the time dependence of the state-space matrices.

Given initial conditions and , you can iterate these equations to perform the filtering. Note that you must update both the state estimates and error covariance matrices at each time sample.


  Steady-State Design Time-Varying Design