Development Of Test Bench Of Al Electrolysis Control System Based On Embedded PC

With the rapid development of the technology of computer and automation, the computer control system is widely used in the manufacture of Al electrolysis and the efficiency is improved and the life-span of the electrobath is increased. These years people are trying to apply control arithmetic more advanced, such as adaptive control, fuzzy control and expert systerm etc, so we decided to design a hardwar&software bench which can be used to test these control arithmetic, it can simply but independently contrl the process of Al electrolysis, and also can control the process according to the better arithmetic which is inputted by users.The test bench is a distributed system and is based on embedded PC. Interrupt and event queue are adopted to schedule tasks, which ensures its real-time performance. To avoid the serious electromagnetic interferer, the analog signals are transformed to frequency pulses which are transferred to the kernel of the system. In the measure of the groove voltage, the method of float-ground is adopted to avoid the high common signal and the range switch circuit is designed to solve the conflict of the wide dynamic range and the high precision. least square Curvefit is adopted to reduce the system error. To eliminate the serious random noises which exist in the analog sigals, the frequency spectrum of the signals are analyzed, then several digital filteration arithmetics are compared with each other and the best is selected. In the control of electrode distance, a compromise arithmetics is used to solve the conflict of the slow control period and the excess adjustment. The system networking is also discussed, the structure and the communication protocol are schemed and designed.In the end, the experience is summarized, which is about how to develop a measure&control system based on embedded PC, and some advices improve on the test bench are put forward.