毕业设计（论文）单片机温度控制英文文献.docVIP

Temperature Control Using a Microcontroller: An Interdisciplinary Undergraduate Engineering Design Project James S. McDonald Department of Engineering Science Trinity University San Antonio, TX 78212 Abstract This paper describes an interdisciplinary design project which was done under the author’s supervision by a group of four senior students in the Department of Engineering Science at Trinity University. The objective of the project was to develop a temperature control system for an air-filled chamber. The system was to allow entry of a desired chamber temperature in a prescribed range and to exhibit overshoot and steady-state temperature error of less than 1 degree Kelvin in the actual chamber temperature step response. The details of the design developed by this group of students, based on a Motorola MC68HC05 family microcontroller, are described. The pedagogical value of the problem is also discussed through a description of some of the key steps in the design process. It is shown that the solution requires broad knowledge drawn from several engineering disciplines including electrical, mechanical, and control systems engineering. 1 Introduction The design project which is the subject of this paper originated from a real-world application. A prototype of a microscope slide dryer had been developed around an OmegaTM model CN-390 temperature controller, and the objective was to develop a custom temperature control system to replace the Omega system. The motivation was that a custom controller targeted specifically for the application should be able to achieve the same functionality at a much lower cost, as the Omega system is unnecessarily versatile and equipped to handle a wide variety of applications. The mechanical layout of the slide dryer prototype is shown in Figure 1. The main element of the dryer is a large, insulated, air-filled chamber in which microscope slides, each with a tissue sample encased in paraffin, can be set on caddies. In order that the p