外文翻译-PID控制简介.doc

英语资料及译文 About PID control Recently automation technology is based on the concept of feedback. Elements of feedback theory consist of three parts: measurement, comparison and implementation. Measurement variables of concern, compared with expectations, with the control system to correct the error response. The theory and application of automatic control, the key is to make the correct measurement and comparison of how best to rectify the system. PID (proportional - integral - differential) controller as the first practical use of the controller more than 50 years of history, is still the most widely used industrial controller. Simple PID controller, the use of the system does not accurately model a prerequisite that they have become the most widely used controller. PID controller is the proportion of cells (P), integral unit (I) and the differential unit (D) component. Because of its wide range of uses, the use of flexible, has been serialized products, the use of only three parameters setting (Kp, Ti and Td) can be. In many cases, does not necessarily need all three modules, which can take 1-2 unit, but the proportion of the control unit is essential. First of all, PID broad range of applications. Although many industrial processes or time-varying non-linear, but can be simplified through their basic non-linear and dynamic characteristics of the system over time, so that you can control the PID. Secondly, PID parameter can tune easier. That is, PID parameters Kp, Ti and Td can be based on the dynamic characteristics of the process of setting a timely manner. If the dynamic characteristics of the process of change, for example, changes may be caused by the load dynamic characteristics of the system changes, PID parameters can be re-tuning. Third, PID controller in practice is to be improved continuously, the following are two examples of improvements. In factories, we always see a lot of loops are in manual, and because of the difficulty of the course so that the au