智能烘箱温度控制器设计-英文翻译(3)

proportional plus derivative (PD) controller can improve system dynamic characteristics in the process of adjustment.

Implementation concrete method of PID control principle varies because of the system. In our system, the incremental calculation method is adopted, and the output of the control volume is adopted the form of the output of the position type. In the numerical control system, the mathematical model of the control law evolved into:

Uo Uo 1 Kp ei ei 1 T ei Td ei 2ei 1 ei 2

Among them: T for acquisition cycle; , ei ei, ei - 1-2 for this moment, a moment again, before the moment of differential signal. Three moments before the benefits of this approach is to simply keep the difference signal, and output control quantity of the initial value is not accurate, can quickly into the stability of control process.

The PID controller parameter setting is the core content of control system design. It is determined according to the character of the charged process of PID controller is the size of the proportion coefficient, integral and differential time. The PID controller parameter setting method are many, in summary there are two broad categories: one is the theoretical calculation of setting method. It is mainly based on the mathematical model of the system, after the theory calculate and determine the controller parameters. Calculation data obtained by this method won't be able to use directly, also must be adjusted and modified through the engineering practice. Second is