Stability and Control of Aircraft Systems: Introduction to Classical Feedback Control

Description

In the current climate of increasing complexity and functional integration in all areas of engineering and technology, stability and control are becoming essential ingredients of engineering knowledge. Many of today’s products contain multiple engineering technologies, and what were once simple mechanical, hydraulic or pneumatic products now contain integrated electronics and sensors. Control theory reduces these widely varied technical components into their important dynamic characteristics, expressed as transfer functions, from which the subtleties of dynamic behaviours can be analyzed and understood.

Stability and Control of Aircraft Systems is an easy-to-read and understand text that describes control theory using minimal mathematics. It focuses on simple rules, tools and methods for the analysis and testing of feedback control systems using real systems engineering design and development examples.

• Clarifies the design and development of feedback control systems
• Communicates the theory in an accessible manner that does not require the reader to have a strong mathematical background
• Illustrated throughout with figures and tables

Stability and Control of Aircraft Systems provides both the seasoned engineer and the graduate with the know-how necessary to minimize problems with fielded systems in the area of operational performance.

 

Table of Contents

Series Preface.

Preface.

1. Developing the Foundation.

1.1 Engineering Units.

1.1.1 International System of Units (SI).

1.1.2 US/Imperial Units System.

1.1.3 Comparing the SI and US/Imperial Units Systems.

1.2 Block Diagrams.

1.2.1 Examples of Summation (or Comparison) Devices.

1.3 Differential Equations.

1.3.1 Using the ‘D’ Notation.

1.4 Spring–Mass System Example.

1.4.1 The Standard Form of Second-order System Transfer Function.

1.5 Primer on Complex Numbers.

1.5.1 The Complex Sinusoid.

1.6 Chapter Summary.

2. Closing the Loop.

2.1 The Generic Closed Loop System.

2.1.1 The Simplest Form of Closed Loop System.

2.2 The Concept of Stability.

2.3 Response Testing of Control Systems.

2.4 The Integration Process.

2.5 Hydraulic Servo-actuator Example.

2.6 Calculating Frequency Response.

2.6.1 Frequency Response of a First-order Lag.

2.6.2 Frequency Response of a Second-order System.

2.7 Aircraft Flight Control System Example.

2.7.1 Control System Assumptions.

2.7.2 Open Loop Analysis.

2.7.3 Closed Loop Performance.

2.8 Alternative Graphical Methods for Response Analysis.

2.8.1 The Nyquist Diagram.

2.8.2 Deriving Closed Loop Response from Nyquist Diagrams.

2.8.3 The Nichols Chart.

2.8.4 Graphical Methods – Summary Comments and Suggestions.

2.9 Chapter Summary.

3. Control System Compensation Techniques.

3.1 Control System Requirements.

3.2 Compensation Methods.

3.2.1 Proportional Plus Integral Control.

3.2.2 Proportional Plus Integral Plus Derivative Control.

3.2.3 Lead–Lag Compensation.

3.2.4 Lag–Lead Compensation.

3.2.5 Feedback Compensation.

3.3 Applications of Control Compensation.

3.3.1 Proportional Plus Integral Example.

3.3.2 Lead–Lag Compensation Example.

3.3.3 Class 2 System Design Example.

3.4 Chapter Summary.

4. Introduction to Laplace Transforms.

4.1 An Overview of the Application of Laplace Transforms.

4.2 The Evolution of the Laplace Transform.

4.2.1 Proof of the General Case.

4.3 Applying Laplace Transforms to Linear Systems Analysis.

4.3.1 Partial Fractions.

4.4 Laplace Transforms – Summary of Key Points.

4.5 Root Locus.

4.5.1 Root Locus Construction Rules.

4.5.2 Connecting Root Locus to Conventional Linear Analysis.

4.6 Root Locus Example.

4.7 Chapter Summary.

5. Dealing with Nonlinearities.

5.1 Definition of Nonlinearity Types.

5.2 Continuous Nonlinearities.

5.2.1 Engine Fuel Control System Example.

5.3 Discontinuous Nonlinearities.

5.3.1 Stability Analysis with Discontinuous Nonlinearities.

5.4 The Transport Delay.

5.5 Simulation.

5.6 Chapter Summary.

6. Electronic Controls.

6.1 Analog Electronic Controls.

6.1.1 The Operational Amplifier.

6.1.2 Building Analog Control Algorithms.

6.2 The Digital Computer as a Dynamic Control Element.

6.2.1 Signal Conversion.

6.2.2 Digital Controller Architectures.

6.3 The Stability Impact of Digital Controls.

6.4 Digital Control Design Example.

6.5 Creating Digital Control Algorithms.

6.5.1 The Integrator.

6.5.2 The First-order Lag.

6.5.3 The Pseudo Derivative.

6.6 Chapter Summary.

7. Concluding Commentary.

7.1 An Overview of the Material.

7.2 Graphical Tools.

7.3 Compensation Techniques.

7.3.1 Integral Wind-up.

7.3.2 Avoid Using Pure Derivative Action.

7.3.3 Mechanical Stiffness Estimates are Always High.

7.4 Laplace Transforms and Root Locus Techniques.

7.5 Nonlinearities.

7.6 Digital Electronic Control.

7.7 The Way Forward.

Index.