This article provides a tutorial introduction to visual servo control of robotic manipulators. Since the topic spans many disciplines our goal is limited to providing a basic conceptual framework. We begin by reviewing the prerequisite topics from robotics and computer vision, including a brief review of coordinate transformations, velocity representation, and a description of the geometric aspects of the image formation process. We then present a taxonomy of visual servo control systems. The two major classes of systems, position-based and image-based systems, are then discussed in detail. Since any visual servo system must be capable of tracking image features in a sequence of images, we also include an overview of feature-based and correlation-based methods for tracking. We conclude the tutorial with a number of observations on the current directions of the research field of visual servo control.

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A tutorial on visual servo control

A tutorial account of variable structure control with sliding mode is presented. The purpose is to introduce in a concise manner the fundamental theory, main results, and practical applications of this powerful control system design approach. This approach is particularly attractive for the control of nonlinear systems. Prominent characteristics such as invariance, robustness, order reduction, and control chattering are discussed in detail. Methods for coping with chattering are presented. Both linear and nonlinear systems are considered. Future research areas are suggested and an extensive list of references is included. >

Variable structure control: a survey

Mobile robots range from the Mars Pathfinder mission's teleoperated Sojourner to the cleaning robots in the Paris Metro. This text offers students and other interested readers an introduction to the fundamentals of mobile robotics, spanning the mechanical, motor, sensory, perceptual, and cognitive layers the field comprises. The text focuses on mobility itself, offering an overview of the mechanisms that allow a mobile robot to move through a real world environment to perform its tasks, including locomotion, sensing, localization, and motion planning. It synthesizes material from such fields as kinematics, control theory, signal analysis, computer vision, information theory, artificial intelligence, and probability theory. The book presents the techniques and technology that enable mobility in a series of interacting modules. Each chapter treats a different aspect of mobility, as the book moves from low-level to high-level details. It covers all aspects of mobile robotics, including software and hardware design considerations, related technologies, and algorithmic techniques.] This second edition has been revised and updated throughout, with 130 pages of new material on such topics as locomotion, perception, localization, and planning and navigation. Problem sets have been added at the end of each chapter. Bringing together all aspects of mobile robotics into one volume, Introduction to Autonomous Mobile Robots can serve as a textbook or a working tool for beginning practitioners.

http://www.gbv.de/dms/hebis-darmstadt/toc/120387220.pdf

Introduction to Autonomous Mobile Robots

The technology of hydrodynamic modeling and marine craft motion control systems has progressed greatly in recent years. This timely survey includes the latest tools for analysis and design of advanced guidance, navigation and control systems and presents new material on underwater vehicles and surface vessels. Each section presents numerous case studies and applications, providing a practical understanding of how model-based motion control systems are designed.

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Handbook of Marine Craft Hydrodynamics and Motion Control: Fossen/Handbook of Marine Craft Hydrodynamics and Motion Control

Nonlinear dynamical systems have been used in many disciplines to model complex behaviors, including biological motor control, robotics, perception, economics, traffic prediction, and neuroscience. While often the unexpected emergent behavior of nonlinear systems is the focus of investigations, it is of equal importance to create goal-directed behavior e.g., stable locomotion from a system of coupled oscillators under perceptual guidance. Modeling goal-directed behavior with nonlinear systems is, however, rather difficult due to the parameter sensitivity of these systems, their complex phase transitions in response to subtle parameter changes, and the difficulty of analyzing and predicting their long-term behavior; intuition and time-consuming parameter tuning play a major role. This letter presents and reviews dynamical movement primitives, a line of research for modeling attractor behaviors of autonomous nonlinear dynamical systems with the help of statistical learning techniques. The essence of our approach is to start with a simple dynamical system, such as a set of linear differential equations, and transform those into a weakly nonlinear system with prescribed attractor dynamics by means of a learnable autonomous forcing term. Both point attractors and limit cycle attractors of almost arbitrary complexity can be generated. We explain the design principle of our approach and evaluate its properties in several example applications in motor control and robotics.

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Dynamical movement primitives: Learning attractor models for motor behaviors

In this chapter, two basic robot components are treated: actuators and sensors. In the first part, the features of an actuating system are presented in terms of the power supply, power amplifier, servomotor and transmission. In view of their control versatility, two types of servomotors are used; namely, electric servomotors for actuating the joints of small and medium size manipulators, and hydraulic servomotors for actuating the joints of large size manipulators. The models describing the input/output relationship for such servomotors are derived. In the second part, proprioceptive sensors are presented which allow measurements of the quantities characterizing the internal state of the manipulator; namely, encoders and resolvers for joint position measurement, tachometers for joint velocity measurement; further, exteroceptive sensors are presented including force sensors for end-effector force measurement and vision sensors for object image measurements when the manipulator interacts with the environment.

Actuators and Sensors

An exact method of analysis is presented for a class of pulse-modulated feedback control systems which can be modeled by a multiple-loop nonlinear feedback system The nonlinearity has a hysteresis characteristic By means of the Tsypkin-Hamel criterion, suitably modified, a set of equations is obtained, determining the switching frequency, duty cycle, and steady-state dc error Based on the graphical form of these equations, a design procedure is set forth Specific cases have been examined and peculiar phenomena are evidenced; experimental data verify both the chosen model and the suggested procedures A simplified pulse ratio modulator is also presented

Analysis and Design of Pulse Ratio Modulated Feedback Control Systems

Different strategies to deal with edge-following tasks for robotic manipulators are analyzed and compared in the common framework provided by the parallel control technique, which proves a flexible tool for handling interaction tasks. Simulation results show that the use of force-based logic in the task planning results in helpful support for the operation of the robot control system. >

Lorenzo Sciavicco

Papers

Actuators and Sensors

Analysis and Design of Pulse Ratio Modulated Feedback Control Systems

Edge-following strategies using the parallel control formulation

Jacobian-based algorithms: A bridge between kinematics and control

Adaptive Control Design in Servosystems