2nd Edition

Vehicle Dynamics, Stability, and Control

By Dean Karnopp Copyright 2013
    326 Pages 121 B/W Illustrations
    by CRC Press

    Anyone who has experience with a car, bicycle, motorcycle, or train knows that the dynamic behavior of different types of vehicles and even different vehicles of the same class varies significantly. For example, stability (or instability) is one of the most intriguing and mysterious aspects of vehicle dynamics. Why do some motorcycles sometimes exhibit a wobble of the front wheel when ridden "no hands" or a dangerous weaving motion at high speed? Why does a trailer suddenly begin to oscillate over several traffic lanes just because its load distribution is different from the usual? Other questions also arise: How do humans control an inherently unstable vehicle such as a bicycle and how could a vehicle be designed or modified with an automatic control system to improve its dynamic properties?

    Using mainly linear vehicle dynamic models as well as discussion of nonlinear limiting effects, Vehicle Dynamics, Stability, and Control, Second Edition answers these questions and more. It illustrates the application of techniques from kinematics, rigid body dynamics, system dynamics, automatic control, stability theory, and aerodynamics to the study of the dynamic behavior of a number of vehicle types. In addition, it presents specialized topics dealing specifically with vehicle dynamics such as the force generation by pneumatic tires, railway wheels, and wings.

    The idea that vehicles can exhibit dangerous behavior for no obvious reason is in itself fascinating. Particularly obvious in racing situations or in speed record attempts, dynamic problems are also ubiquitous in everyday life and are often the cause of serious accidents. Using relatively simple mathematical models, the book offers a satisfying introduction to the dynamics, stability, and control of vehicles.

    Introduction: Elementary Vehicles
    Tapered Wheelset on Rails
    The Dynamics of a Shopping Cart

    Rigid Body Motion
    Inertial Frame Description
    Body-Fixed Coordinate Frame Description
    Spin Stabilization of Satellites
    Bond Graphs for Rigid Body Dynamics

    Stability of Motion: Concepts and Analysis
    Static and Dynamic Stability
    Eigenvalue Calculations and the Routh Criterion

    Pneumatic Tire Force Generation
    Tire-Road Interaction
    Lateral Forces
    Longitudinal Forces
    Combined Lateral and Longitudinal Forces

    Stability of Trailers
    Single-Degree-of-Freedom Model
    Two-Degree-of-Freedom Model
    A Third-Order Model
    A Model Including Rotary Damping

    Stability and Dynamics of an Elementary Automobile Model
    Transfer Functions for Front- and Rear-Wheel Steering
    Yaw Rate and Lateral Acceleration Gains
    Steady Cornering
    Acceleration and Yaw Rate Gains
    Dynamic Stability in a Steady Turn
    Limit Cornering

    Two-Wheeled and Tilting Vehicles
    Steering Control of Banking Vehicles
    Steering Control of Lean Angle

    Stability of Casters
    A Vertical Axis Caster
    An Inclined Axis Caster
    A Vertical Axis Caster with Pivot Flexibility
    A Vertical Axis Caster with Pivot Flexibility and a Finite Cornering Coefficient
    A Caster with Dynamic Side Force Generation

    Aerodynamics and the Stability of Aircraft
    A Little Airfoil Theory
    Derivation of the Static Longitudinal Stability Criterion for Aircraft
    The Phugoid Mode
    Dynamic Stability Considerations: Comparison of Wheels and Wings
    The Effect of Elevator Position on Trim Conditions

    Rail Vehicle Dynamics
    Modeling a Wheelset
    Wheel-Rail Interaction
    Creepage Equations
    The Equations of Motion
    The Characteristic Equation
    Stability Analysis and Critical Speed

    Vehicle Dynamics Control
    Stability and Control
    From ABS to VDC and TVD
    Active Steering Systems
    Limitations of Active Vehicle Dynamics Control

    Appendix: Bond Graphs for Vehicle Dynamics
    A Bond Graph for the Two-Degree-of-Freedom Trailer
    A Bond Graph for a Simple Car Model
    A Bond Graph for a Simple Airplane Model


    Dean Karnopp

    As with Prof. Karnopp’s other books, a wide range of topics are presented in Vehicle Dynamics, Stability, and Control. If one enjoys Prof. Karnopp’s other textbooks, as I do, then this textbook is another wonderful adventure through a complicated and interesting technical subject.
    —Robert M. Sexton, Virginia Commonwealth University

    I will consider adopting this book for my vehicle dynamics course. The modeling is a step above the book currently used and should improve the students’ understanding of the subject matter. The material on active control of vehicles is a good addition.
    —Jack E. Helms, Louisiana State University

    The material is written in a very direct way. Reading it goes on smoothly to the end without trouble. And when you have finished, you happily have understood a very complicated issue. … I do think Prof. Karnopp is one of the very best professors in Mechanical Engineering living today. The book can be recommended both to beginners and to experienced scientists or engineers. Beginners will take advantage from the very easy way the complicated topics are presented and made easy to grasp. Experienced scientists can get further insight into basic phenomena presented with unsurpassed inspiring style.
    —G. Mastinu, Politecnico di Milano

    The book includes a rich compilation of examples of the application of basic methods of stability analysis to vehicle dynamics behavior, both attractive to the lecturer and students. It brings two subjects — stability of motion and vehicle dynamics, which are often lectured separately — together and reveals the benefit of an integrative view. … The book offers a very attractive introduction to the analysis of stability of motion from a comprehensive vehicle dynamics point of view. Examples include automobiles, aircrafts, railway vehicles, vehicle dynamics control etc., which give engineering students an easy understanding of the application of mathematical methods to illustrative problems on the dynamic behaviour of vehicles. Basic models on the external force generation at tires, railway wheels, or wings are presented as well and allow for a more comprehensive understanding of vehicle dynamics.
    —Manfred Plöchl, Vienna University of Technology

    The chapters provide good and wide basic knowledge in the field of vehicle stability. The book is focused on analogies between several technical fields, which – in my mind – gives a good understanding of the physical effects behind. It is easy to read and to understand, since it uses simple words and refers to daily-life-examples. As explicitly mentioned by the author, it is not aimed at explaining the physics deeply. The focus is giving an overview and providing a fundamental and solid base of knowledge. In my opinion, this is achieved successfully. I would recommend this book to students or engineers who are interested in getting a good overview with respect to vehicle stability and in understanding how various physical effects are connected with each other.
    —Dr. Andreas Wagner, Manager Vehicle Attributes of Chassis Concepts, Audi, Ingolstadt, Germany

    Praise for the First Edition:
    ...a comprehensive analysis of the vibration characteristic parameter which defines stability. The author widely use[s] mathematical reasoning to establish the optimum ways to improve vehicle stability. ... The book is a valuable reference ... it is very useful for professors, researchers, and students interested in the vehicle stability field.
    —Prof. Dan Dascalescu, Ph.D.

    The monograph will be useful for students and engineers specializing in the related fields.
    Zentralblatt MATH