UNIVERSITY OF NATAL MODEL J:JREDICTIVE CONTROL OF HYBRID SYSTEMS JASMEER RAMLAL MODEL PREDICTIVE CONTROL OF HYBRID SYSTEMS

ii Hybrid systems combine the continuous behavior evolution specified by differential equations with discontinuous changes specified by discrete event logic. Usually these systems in the processing indushy can be identified as having to depend on discrete decisions regarding their operation. In process control there therefore is a challenge to automate these decisions. A model predictive control (MPC) strategy was proposed and verified for the control of hybrid systems. More specifically, the dynamic mah"ix control (DMC) framework commonly used in industry for the control of continuous variables was modified to deal with mixed integer variables, which are necessalY for the modelling and control of hybrid systems. The algorithm was designed and commissioned in a closed control loop comprising a SCADA system and an optimiser (GAMS). GAMS (General Algebraic Modelling System) is an optimisation package that is able to solve for integer/continuous variables given a model of the system and an appropriate objective function. Online and offline closed loop tests were undertaken on a benchmark interacting tank system and a heating/cooling circuit. The algorithm was also applied to an industrial proble