Linear Incremental Hydraulic Actuators combine one or more short-stroke cylinders, and two or more engaging/disengaging mechanisms into one actuator with long, medium, or even unlimited stroke length. The motion of each single short-stroke actuator concatenated by the engaging/disengaging mechanisms forms the motion of the linear incremental hydraulic actuator. The patterns of how these motions are concatenated form the gaits of a specific linear incremental hydraulic actuator. Linear incremental hydraulic actuators may have more than one gait. In an application, the gaits may be combined to achieve optimal performance at various operating points. The distinguishing characteristic of linear incremental hydraulic actuators is the incremental motion. The term incremental actuator is seen as analogous to the incremental versus absolute position sensor. Incremental actuators realize naturally relative positioning. Incremental motion means also that the behavior does not depend on an absolute position but only on the relative position within a cycle or step. Incremental actuators may realize discrete incremental or continuous incremental motion. Discrete incremental actuators can only approach discrete positions, whereby stepper drives are one prominent example. In contrast, continuous incremental actuators may approach any position. Linear electric motors are one example of continuous incremental actuators. The actuator has no inherent limitation in stroke length, as every step or cycle adds only to the state at the beginning of the step or cycle and does not depend on the absolute position. This led to the alternative working title Hydraulic Infinite Linear Actuator. Linear incremental hydraulic actuator provides long stroke, high force, and linear motion and has the potential to decrease the necessary resource usage,minimize environmental impact, e.g. from potential oil spillage,extend the range of feasible products: longer, stiffer, better, etc. This thesis presents an analysis of the characteristics and properties of linear incremental hydraulic actuators as well as the gaits and possible realizations of some gaits. The gait for continuous, smooth motion with two cylinders is comprehensively studied and a control concept for the tracking problem is proposed. The control concept encapsulates the complexity of the linear incremental hydraulic actuator so that an application does not have to deal with it. One other gait, the ballistic gait, which realizes fast, energy-efficient motion, enabling energy recuperation is studied.

Modeling and Control of Precision Actuators explores new technologies that can ultimately be applied in a myriad of industries. It covers dynamical analysis of precise actuators and strategies of design for various control applications. The book addresses four main schemes: modeling and control of precise actuators; nonlinear control of precise actuators, including sliding mode control and neural network feedback control; fault detection and fault-tolerant control; and advanced air bearing control. It covers application issues in the modeling and control of precise actuators, providing several interesting case studies for more application-oriented readers. Introduces the driving forces behind precise actuators Describes nonlinear dynamics of precise actuators and their mathematical forms, including hysteresis, creep, friction, and force ripples Presents the control strategies for precise actuators based on Preisach model as well as creep dynamics Develops relay feedback techniques for identifying nonlinearities such as friction and force ripples Discusses a MPC approach based on piecewise affine models which emulate the frictional effects in the precise actuator Covers the concepts of air bearing stages with the corresponding control method Provides a set of schemes suitable for fault detection and accommodation control of mechanical systems Emphasizing design theory and control strategies, the book includes simulation and practical examples for each chapter; covers precise actuators such as piezo motors, coil motors, air bearing motors, and linear motors; discusses integration among different technologies; and includes three case studies in real projects. The book concludes by linking design methods and their applications, emphasizing the key issues involved and how to implement the precision motion control tasks in a practical system. It provides a concise and comprehensive source of the state-of-the-art developments and results for modeling and control of precise actuators.

The book serves as a unique integrated platform, which not only describes the design methodology of electro-hydraulic actuation systems but also provides insights into the design of the servo valve, which is the most important component in the system. It presents a step-by-step design process, comparative tables, illustrative figures, and detailed explanations. The book focuses on the design and testing of electro-hydraulic actuation systems, which are increasingly being used in motion control applications, particularly in those where precision actuation at high operational rates is of prime importance. It describes in detail the design philosophy of such high-performance systems, presenting a system used as a physical test setup together with experimental results to corroborate the calculations. Of particular interest are the electro-hydraulic servo valves that form the heart of these actuations. These valves are complex and not much data is available in open literature due to OEM propriety issues. In this context, the book discusses the elaborate mathematical models that have been derived and an approach to validate the mathematical models with test results. Presenting the complex methodology in simple language, it will prove to be a valuable resource for students, researchers, and professional engineers alike.

Nonlinear Control Techniques for Electro-Hydraulic Actuators in Robotics Engineering meets the needs of those working in advanced electro-hydraulic controls for modern mechatronic and robotic systems. The non-linear EHS control methods covered are proving to be more effective than traditional controllers, such as PIDs. The control strategies given address parametric uncertainty, unknown external load disturbance, single-rod actuator characteristics, and control saturation. Theoretical and experimental validations are explained, and examples provided. Based on the authors' cutting-edge research, this work is an important resource for engineers, researchers, and students working in EHS.

Contains engineering information for the design of electro hydraulic motion control systems plus problems

Automation based electrohydraulic servo systems have a wide range of applications in nowadays industrial systems. However, they still suffer from several nonlinearities like deadband in electrohydraulic valves, hysteresis, stick-slip friction in valves and cylinders. In addition, all hydraulic system parameters have uncertainties in their values due to the change of temperature while working. This book addresses these problems by designing a suitable intelligent control system that has the ability to deal with the system nonlinearities and parameters uncertainties by a fast and online learning algorithm.