The Design And Simulation Of Resistance Furnace Temperature Control System Based On USB Interface

A higher requirement is required in measurement and control technology, while satisfactory progress has been gained in defferent fields of industrial technology, and new test methods have been created.In order to improve the accuracy of industrial measurement and control ,we complete the design of the software and hardware of the measurement and control system, and improve the control program.As follows, it is most content in this paper:First, K-type thermocouple converter MAX6675 is used in microcomputer measurement and control systems. Compared with traditional system, it has simple peripheral circuit and higher anti-interruption ability. The feasibility of the temperature code is confirmed through simulation in protues.Second, instead of traditional RS232 and PCI bus technology, we adopt USB interface technology to realize the communication between microcomputer AT89S51 and PC, on the base of wonderful understanding to USB1.1 protocol and internal truss of PDIUSBD12, meanwhile, we work out the fireware code, diver and client application of the system.Third, in view of the shortages of VC++, such as numerical computation, graphics processing deficiencies in areas, we utilize a mixed programming method to overcome them, as a result, this method not only gain the powerful computing capabilities of MATLAB, but also succeed the characteristics of good application interface development capabilities, high speed of program execution, as well as good stability of VC++.Fourth, after analysing the simulation result of PID controller which is gained through traditional PID parameter tuning, we find its experience element affect the accuracy of control result. In this paper, a new parameter tuning method, satisfactory PID parameter tuning method, is introduced. The simulation result through MATLAB shows this method has good effct of control and satisfy the control requirement of industry.Fifth, we consider satisfactory PID parameter tuning is short of realtime response capability and anti-interruption ability in actual control, an additional fuzzy adaptive PID control is introduced. After simulation, we find it works better.