自动控制理论课后题答案 06.ppt

Chap 6 The Compensation of the linear control systems Chap 6 The Compensation of  the linear control systems Definition of the compensation: Compensator: The compensator is an additional component or circuit that is inserted into a control system to compensate for a deficient performance. Comparing active compensation controllers and passive compensation controllers 6.3 Cascade compensation by Root loci method 6.3.1 Phase-lead compensation (P569) Example 6.3.1: The root loci of the system shown in Fig.6.3.1 Fig.6.3.1 solution Analysis: unstable. phase-lead compensation 6.3 Cascade compensation by Root loci method Fig.6.3.2 6.3 Cascade compensation by Root loci method Fig.6.3.3 There are two approaches to determine zc and pc . (1) Maximum α method (2) Method based on the open-loop gain 6.3 Cascade compensation by Root loci method For this example we choose the Maximum α method: Fig.6.3.3 In terms of the law of sines: Root locus of the compensted system 6.3 Cascade compensation by Root loci method The root locus of the compensated system is shown in Fig.6.3.4 Fig.6.3.4 Steps of the cascade phase-lead Compensation: (1) Determine the dominant roots based on the performance specifications of the system: (2) plot the root locus of the system and analyze what compensation device should be applied. * * P553 §6-1 Introduction 6.1.1 definition of compensation 6.1.2 types of compensation §6-2 The basic controller operation analysis 6.2.1 PID controller 6.2.2 phase-lead controller 6.2.3 phase-lag controller 6.2.4 phase lag-lead controller §6-3 Cascade compensation method of Root loci §6-4 Cascade compensation method of frequency- Domain §6-5 Feedback compensation passive compensation active compensation 6.1 Introduction 6.1.1 What is compensation or correction of a control system ? Only designing the parameter of the system the system’s requirement