Delay Compensator: an Approach to Reduce the Variable Sampling to Actuation Delay Effect in Distributed Real-time Control Systems

Abstract

This work presents the delay compensator an approach to deal with the sampling to actuation delay effects in real-time distributed control systems. The delay compensator approach bases its action on the amount of the sampling to actuation delay affecting the system at each control iteration and can be applied to distributed systems using off-line or on-line scheduling provided that the sampling to actuation delay can be evaluated. To show the effectiveness of the proposed approach we present an implementation using a fuzzy compensator to minimize the variable sampling to actuation delay effect on an existing real-time distributed controller. The compensator works with a very simple set of rules and generates an output that is added to the one provided by the existing controller following a modified additive feedforward scheme. The rules of the fuzzy compensator are based in a linear approach of the effect of the sampling to actuation delay. Experimental results show that the use of the fuzzy compensator improves the control performance of the real-time distributed control system and can be easily added to an existing system.