Optimization of block-floating-point realizations for digital controllers with finite-word-length considerations.
The closed-loop stability issue of finite-precision realizations was investigated for digital controllers implemented in block-floating-point format. The controller coefficient perturbation was analyzed resulting from using finite word length (FWL) block-floating-point representation scheme. A block-floating-point FWL closed-loop stability measure was derived which considers both the dynamic range and precision. To facilitate the design of optimal finite-precision controller realizations, a computationally tractable block-floating-point FWL closed-loop stability measure was then introduced and the method of computing the value of this measure for a given controller realization was developed. The optimal controller realization is defined as the solution that maximizes the corresponding measure, and a numerical optimization approach was adopted to solve the resulting optimal realization problem. A numerical example was used to illustrate the design procedure and to compare the optimal controller realization with the initial realization.
Wu
Jun
J
National Key Laboratory of Industrial Control Technology, Institute of Advanced Process Control, Zhejiang University, Hangzhou 310027, China. jwu@iipc.zju.edu.cn
Hu
Xie-he
XH
Chen
Sheng
S
Chu
Jian
J
D000703:Analog-Digital Conversion; D005246:Feedback; D009716:Numerical Analysis, Computer-Assisted; D012815:Signal Processing, Computer-Assisted