Implementation of H-Infinity Control Algorithms for Sensor-Constrained Mechatronic Systems Using Low-Cost Microcontrollers

This paper introduces a novel method which is intended to assist in the design and implementation of optimal H-infinity (H _infin) algorithms in low-cost mechatronic applications. The particular problem considered is position control in a situation where there are both sensor-related uncertainties (caused by low-resolution sensors) and limited computational resources. The first part of the method presented in this paper describes how to design the H _infin algorithm based on dynamic features of the sensor. The second part of the method involves finding a suitable numerical controller representation in order to reduce memory and CPU load. Evaluation of the method is based on empirical studies using three industrial sensors employed in a sub-acted robot. Results for a classic proportional integral derivative (PID) controller are included, in order to provide comparisons with the H _infin approach. In the empirical evaluation, the PID implementation shows marginal stability when the low-resolution sensor is employed; by contrast, the H _infin implementation is found to remain stable in the same circumstances.