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Optimization of block-floating-point realizations for digital controllers with finite-word-length considerations

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Abstract

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.

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Authors and Affiliations

  1. National Key Laboratory of Industrial Control Technology, Institute of Advanced Process Control, Zhejiang University, 310027, Hangzhou, China

    Wu Jun, Hu Xie-he & Chu Jian

  2. Department of Electronics and Computer Science, University of Southampton, SO17 1BJ, Southampton, UK

    Chen Sheng

Authors
  1. Wu Jun
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  2. Hu Xie-he
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  3. Chen Sheng
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  4. Chu Jian
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Corresponding author

Correspondence to Wu Jun.

Additional information

Project supported by the National Naturla Science Foundation of China (No. 60174026) and the Scientific Research Foundation for Returned Overseas Chinese Scholars of Zhejiang Province (No. J20020546).

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Jun, W., Xie-he, H., Sheng, C. et al. Optimization of block-floating-point realizations for digital controllers with finite-word-length considerations. J. Zheijang Univ.-Sci. 4, 651–657 (2003). https://doi.org/10.1631/BF02851605

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  • DOI: https://doi.org/10.1631/BF02851605

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