自动控制理论-第二招侣.pptVIP

2.6 Block Diagram Models;a;Block diagram representation The block represents the function or dynamic characteristics of the component and is represented by a transfer function. The complete block diagram shows how the functional components are connected and the mathematic equations that determine the response of each component. ;Example;Block Diagram Manipulations Rule 1 ( Combining serial blocks ) Rule 2 ( Combining parallel blocks ) Rule 3 ( Closing a feedback loop ) Rule 4 ( Moving a summing junction ahead of a block ) Rule 5 ( Moving a summing junction past a block ) Rule 6 ( Moving a branch(pickoff) point ahead of a block ) Rule 7 ( Moving a branch point past a block );;Rule 2 ( Combining parallel blocks ) principle of superposition ;Rule 3 ( Closing a feedback loop ) ;Example 2.1;Fig. Block Diagram of RC network ;; Rule 4 ( Moving a summing junction ahead of a block );Rule 5 ( Moving a summing junction past a block ) Distributive property;Moving summing junctions between each other. (Interchange);Rule 6 ( Moving a pickoff point ahead of a block );Rule 7 ( Moving a pickoff point past a block );Moving a pickoff points between each other. (Interchange);;Example 2.2 Simplify the following block diagram.;;;;;Transfer function of close-loop system;Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.;Multiple inputs for error;Open-loop transfer function: the ratio of the feedback signal B(s) to the actuating error signal E(s) is called the open-loop transfer function:;Characteristic equation: 特征方程 The poles are the roots of the characteristic equation. For a system to be stable, the poles (roots of the characteristic equation) need to have negative real parts, i.e. be on the left half of the complex s-plane.;2.7 Signal flow graphs (SFG);;;Terms: Source is a node with only outgoing branches. Sink is a node with only incoming branches. Path is a grou