Digital Control Systems & Digital PID Controller Lei Xie Institute of Industrial Control, Zhejiang University, Hangzhou, P. R. China 2013/04/03

Problem Discussion For an unknown stable temperature control system, can you determine PID parameters in Offline and Online tuning methods ? Please realize the industrial PID controller in Simulink ? For the fast flow control loop, show me your tuning principle and explain why. For the AVERAGE level control loop, show me your tuning principle and explain why. Explain the existing reason of reset windup and show me your prevention schemes

Contents Concept of Digital Control Systems Selection of Digital Filters Digital PID Controllers and Its Improved Version Concept of Distributed Control Systems Summary

Construction of Digital Control Systems Analog Control System Digital Control System

General Digital Controller

Digital Filters Median Filter (中值滤波器) Average Filter (平均滤波器) Weighed Average Filter (加权平均滤波器)

Digital Filters (cont.) First Order Filter (一阶滤波器) Compare common-used digital filters See ../PIDControl/DigitalFilter.mdl

Digital PID Positional Algorithm Ideal analog PID algorithm Digital PID positional algorithm （位置算法）

Digital PID Incremental Algorithm Digital PID positional algorithm Digital PID incremental algorithm（增量算法）

PID incremental algorithm with derivative action first Digital PID incremental algorithm Digital PID incremental algorithm with derivative action first （微分先行PID增量算法）

Industrial Digital PID Module Problem: （1）Programming；（2）Smooth A/M switching；（3）Reset windup prevention

Configuration of Distributed Control Systems (DCS，集散控制系统) Analyze the meaning of distributed control ? Why do people prefer DCS ?

Summary for Single-loop PID Control Control Objective Determination of Process Characteristics Type Selection of Control Valves Action Selection of PID Controllers Selection of PID Controller Types Realization of PID Controller Tuning of PID Parameters