Habituating control strategies for process control

By “reverse engineering” the functions of a specific biological system, habituating control strategies are developed for process control applications. A habituating control system has the distinguishing property of more more manipulated inputs than controlled outputs; with the inputs differing significantly in their dynamic effect on the outputs and in the relative costs of manipulating each one. A habituating controller coordinates the use of all the available inputs to achieve high-performance output objectives while simulatneously minimizing the cost of taking control action. The “baroreceptor reflex,” the control system responsible for short-term blood pressure regulation, provides the biological paradigm for the analysis and design of the habituating control structure. Its main characteristics are discussed from a process control perspective, indicating that the robust, high-performance control, characteristic of biological systems is partly due to such habituating control architectures. The broad range of potential process applications is illustrated with two examples. Two basic strategies are presented for the design of habituating controllers for linear systems with two inputs and one output: the direct synthesis approach and the model predictive approach. Compared to previous techniques for multiple-input, single-output systems, the direct synthesis strategy is straightforward and systematic. Simulation results demonstrate the superior performance of habituating control compared to conventional techniques for which the number of inputs and outputs are equal.