Wu, J.Chen, S.Whidborne, James F.Chu, J.2011-11-162011-11-162004-03-20Jun Wu, Sheng Chen, James F. Whidborne, Jian Chu, Optimal realizations of floating-point implemented digital controllers with finite word length considerations, International Journal of Control, Volume 77, Issue 5, Mar 2004, Pages 427 - 4400020-7179http://dx.doi.org/10.1080/0020717042000208296http://dspace.lib.cranfield.ac.uk/handle/1826/1237The closed-loop stability issue of finite word length (FWL) realizations is investigated for digital controllers implemented in floating-point arithmetic. Unlike the existing methods which only address the effect of the mantissa bits in floating-point implementation to the sensitivity of closed-loop stability, the sensitivity of closed-loop stability is analysed with respect to both the mantissa and exponent bits of floating-point implementation. A computationally tractable FWL closed-loop stability measure is then defined, and the method of computing the value of this measure is given. The optimal controller realization problem is posed as searching for a floating-point realization that maximizes the proposed FWL closed-loop stability measure, and a numerical optimization technique is adopted to solve for the resulting optimization problem. Simulation results show that the proposed design procedure yields computationally efficient controller realizations with enhanced FWL closed-loop stability performance.en-UKArticle