Design of a partial model matching based PID controller for a temperature control system

This paper examines a design method of PID controllers based on the partial model matching for time-lag systems. In most processes, PID controllers have been widely used because of its simple structure. The partial model matching (PMM) method is one of design schemes for determining control parameters. The PMM can determine control parameters by partial knowledge of a plant. However, according to the conventional PMM method, it is difficult to obtain good control performance for time-lag systems. In this paper, a PMM design scheme inserting a pre-filter for time-lag systems is proposed. By inserting the first order pre-filter whose time constant is τ before a system, the ratio between the time-lag L and the time constant T and user specified parameter τ (L/(T + τ)) of an augmented system becomes small. Moreover the PMM method is applied to the augmented system, and stabilized control performance can be achieved for time-lag systems. The effectiveness of the proposed method is evaluated by a pilot-scale temperature control system.