INPUT OUTPUT STABILITY OF SAMPLED-DATA SYSTEMS

This paper studies the L(p) input-output stability of a continuous-time plant with a discrete-time controller, using the usual arrangement of periodic sampling and zero-order hold. It is noted that even if the hybrid system is exponentially stable, this arrangement does not yield L(p) (1 less-than-or-equal-to p < infinity) stability in general. It is shown that this problem can be alleviated if a strictly causal stable continuous-time filter (e.g., antialiasing filter) is introduced prior to the sampler. For various configurations, L(p) stability is examined in connection with exponential stability.