Self-Tuning Control Of Temperature System Based On Pole Placement Algorithm

Temperature control is a common problem in industry control. Temperature system is a slow time- varying and non-linear system, so it is difficult to control it. To solve this problem, this paper proposed a self-tuning control scheme. It combines the identification about the model coefficient and the design of the controller. System identification adopts algorithm of recursive least squares with leave factor and controller use algorithm of pole placement. So this temperature control system can adjust the parameter of the controller on line, and ensure that the practical pole-zero of the closed-loop system converge to the desired pole-zero. The whole algorithm of the control process is quite simple and convenient to use in engineering.In hardware design part, a programmable peripheral interface board is designed to control the temperate sample input and the control signal output of 12 temperate channels simultaneously. And according to the control signal transferred from the programmable peripheral interface board, a SCR trigger circuit board is designed to control the heater's on and off. This paper not only presents the total structure of hardware part in the temperature system, but also introduces the design principle and interior circuits of two main function models, the programmable peripheral interface board and the SCR trigger circuit board. This temperature control is programmed by application software c++ Builder which developed by Bodand corporation. This programmer can sample 12 temperature channels periodically, realize control algorithm and output control signal. It can also monitor real-time change of temperature on the spot. When process finish it makes the data to table and graph and print them. Furthermore, it use database to manage large of data which come from control process, so it improves the efficiency of programming.In this paper, experimental results are given and analyzed; it concluded that this temperature control system is reliable and robust. It achieves a satisfied effect.