Dynamics Of Controlled Mechanical Systems With Delayed Feedback

Recent years have witnessed a rapid development of active control of various mechanical systems. With increasingly strict requirements for control speed and system performance, the unavoidable time delays in both controllers and actuators have become a serious problem. For instance, all digital controllers, analogue anti aliasing and reconstruction filters exhibit a certain time delay during operation, and the hydraulic actuators and human being interaction usually show even more significant time delays. These time delays, albeit very short in most cases, often deteriorate the control performance or even cause the instability of the system, be cause the actuators may feed energy at the moment when the system does not need it. Thus, the effect of time delays on the system performance has drawn much at tention in the design of robots, active vehicle suspensions, active tendons for tall buildings, as well as the controlled vibro-impact systems. On the other hand, the properly designed delay control may improve the performance of dynamic sys tems. For instance, the delayed state feedback has found its applications to the design of dynamic absorbers, the linearization of nonlinear systems, the control of chaotic oscillators, etc. Most controlled mechanical systems with time delays can be modeled as the dynamic systems described by a set of ordinary differential equations with time delays.

This book presents up-to-date research developments and novel methodologies to solve various stability and control problems of dynamic systems with time delays. First, it provides the new introduction of integral and summation inequalities for stability analysis of nominal time-delay systems in continuous and discrete time domain, and presents corresponding stability conditions for the nominal system and an applicable nonlinear system. Next, it investigates several control problems for dynamic systems with delays including H(infinity) control problem Event-triggered control problems; Dynamic output feedback control problems; Reliable sampled-data control problems. Finally, some application topics covering filtering, state estimation, and synchronization are considered. The book will be a valuable resource and guide for graduate students, scientists, and engineers in the system sciences and control communities.

This is a state-of-the-art treatise on the problems of both nonlinearity and uncertainty in the dynamics and control of engineering systems. The concept of dynamics and control implies the combination of dynamic analysis and control synthesis. It is essential to gain insight into the dynamics of a nonlinear system with uncertainty if any new control strategy is designed to utilize nonlinearity.

The interest of the applied mechanics community in chaotic dynamics of engineering systems has exploded in the last fifteen years, although research activity on nonlinear dynamical problems in mechanics started well before the end of the Eighties. It developed first within the general context of the classical theory of nonlinear oscillations, or nonlinear vibrations, and of the relevant engineering applications. This was an extremely fertile field in terms of formulation of mechanical and mathematical models, of development of powerful analytical techniques, and of understanding of a number of basic nonlinear phenomena. At about the same time, meaningful theoretical results highlighting new solution methods and new or complex phenomena in the dynamics of deterministic systems were obtained within dynamical systems theory by means of sophisticated geometrical and computational techniques. In recent years, careful experimental studies have been made to establish the actual occurrence and observability of the predicted dynamic phenomena, as it is vitally needed in all engineering fields. Complex dynamics have been shown to characterize the behaviour of a great number of nonlinear mechanical systems, ranging from aerospace engineering applications to naval applications, mechanical engineering, structural engineering, robotics and biomechanics, and other areas. The International Union of Theoretical and Applied Mechanics grasped the importance of such complex phenomena in the Eighties, when the first IUTAM Symposium devoted to the general topic of nonlinear and chaotic dynamics in applied mechanics and engineering was held in Stuttgart (1989).

Analysis and control of time-delayed systems have been applied in a wide range of applications, ranging from mechanical, control, economic, to biological systems. Over the years, there has been a steady stream of interest in time-delayed dynamic systems, this book takes a snap shot of recent research from the world leading experts in analysis and control of dynamic systems with time delay to provide a bird's eye view of its development. The topics covered in this book include solution methods, stability analysis and control of periodic dynamic systems with time delay, bifurcations, stochastic dynamics and control, delayed Hamiltonian systems, uncertain dynamic systems with time delay, and experimental investigations of delayed structural control. Contents:Complete Quadratic Lyapunov-Krasovskii Functional: Limitations, Computational Efficiency, and Convergence (Keqin Gu)Recent Approaches for the Numerical Solution of State-Dependent Delay Differential Equations with Discontinuities (Alfredo Bellen)Engineering Applications of Time-Periodic Time-Delay Systems (Gábor Stépán)Synchronization in Delay-Coupled Complex Networks (Eckehard Schöll)Stochastic Dynamics and Optimal Control of Quasi Integrable Hamiltonian Systems with Time-Delayed Feedback Control (Weiqiu Zhu and Zhonghua Liu)Delay Induced Strong and Weak Resonances in Delayed Differential Systems (Jian Xu, Wanyong Wang)Stability and Hopf Bifurcation of Time-Delay Systems with Complex Coefficients (Zaihua Wang and Junyu Li)Estimation and Control in Time-Delayed Dynamical Systems Using the Chebyshev Spectral Continuous Time Approximation and Reduced Liapunov-Floquet Transformation (Eric A Butcher, Oleg Bobrenkov, Morad Nazari and Shahab Torkamani)Noise-Induced Dynamics of Time-Delayed Stochastic Systems (Yanfei Jin and Haiyan Hu)Some Studies on Delayed System Dynamics and Control (Guo-Pingcai, Long-Xiang Chen and Kun Liu)Switching Control of Uncertain Dynamic Systems with Time Delay (Jian-Qiao Sun, Xiao-Yan Zhang, Zhi-Chang Qin and Shun Zhong) Readership: The researchers in the community of dynamics and control including mechanical, civil, structural, aerospace, naval and electrical engineers. Graduate students pursuing research in the area of dynamics and control. Keywords:Time-Delayed Dynamical Control Systems;Stochastic Dynamics and Optimal Control SystemsKey Features:Professor Jian-Qiao Sun, of University of California-Merced is well-known for his work on stochastic nonlinear dynamical systems and cell mapping methodsProfessor Qian Ding of Tianjin University is well-known for his work on nonlinear dynamics, rotor dynamics and reduced order modeling of complex dynamical systemsThere are many books devoted to time delayed systems, as noted in the authors' proposal, but many don't do justice to control. In addition, the topic of time delayed, non-smooth systems is beginning to receive considerable attention in the literature, but not (well) addressed in any of the current books

This research addresses delay effects in nonlinear systems, which are ubiquitous in various fields of physics, chemistry, biology, engineering, and even in social and economic systems. They may arise as a result of processing times or due to the finite propagation speed of information between the constituents of a complex system. Time delay has two complementary, counterintuitive and almost contradictory facets. On the one hand, delay is able to induce instabilities, bifurcations of periodic and more complicated orbits, multi-stability and chaotic motion. On the other hand, it can suppress instabilities, stabilize unstable stationary or periodic states and may control complex chaotic dynamics. This thesis deals with both aspects, and presents novel fundamental results on the controllability of nonlinear dynamics by time-delayed feedback, as well as applications to lasers, hybrid-mechanical systems, and coupled neural systems.

In industrial engineering and manufacturing, control of individual processes and systems is crucial to developing a quality final product. Rapid developments in technology are pioneering new techniques of research in control and automation with multi-disciplinary applications in electrical, electronic, chemical, mechanical, aerospace, and instrumentation engineering. The Handbook of Research on Advanced Intelligent Control Engineering and Automation presents the latest research into intelligent control technologies with the goal of advancing knowledge and applications in various domains. This text will serve as a reference book for scientists, engineers, and researchers, as it features many applications of new computational and mathematical tools for solving complicated problems of mathematical modeling, simulation, and control.

In this book, we collected recent results on the control of underactuated mechanical systems subject to internal uncertainties and external disturbances. The strategy developed is so universal that it is not restricted to a specific system but a large class of underactuated systems. Several benchmark systems are studied in this book, including detailed literature review, system dynamics derivation, control problem formulation, and simulation verification. The control strategy developed in chapter 4 is able to stabilize all these benchmark systems with satisfactory performance regardless of the underactuated dynamics and various uncertainties. The book is written as a text suitable for graduate students in the advanced course for the control of underactuated systems. It also provides valuable tools for researchers and practicing engineers working on the control of underactuated mechanical systems. Contents:IntroductionPreliminariesUnderactuated System Dynamics and Coordinate TransformationController DesignCart Pole SystemOverhead CranesTORA SystemRotary Inverted PendulumVibration AbsorberPendubotBibliographyIndex Readership: Graduate students, researchers, and academics in control engineering, mechanical engineering, electrical & electronic engineering, and optimization and control theory. Keywords:Adaptive Control;Underactuated Systems;Approximation Technique