Multi-Rate Networked Control of Conic (Dissipative) Systems

This paper presents a novel multi-rate digital-control system which preserves stability while providing robustness to time-delay and data loss. In addition, this architecture allows for high-order anti-aliasing filters to be included which do not adversely affect system stability. Therefore, it allows for improved noise-rejection and system performance as compared to traditional digital control systems. It is shown that this framework, based on passivity-based networked control principles, can be used to control not only passive-(dissipative) systems (systems inside the sector [0, infinity]) but conic-(dissipative) systems which are inside the sector [a, b] in which |a| < b, 0 < b <= infinity. We demonstrate the applicability of our result through the direct position control of a single-degree of freedom haptic paddle which is inside the sector [-tau, infinity] in which 0 < tau < infinity.