The aim of this book is to provide an account of the state of the art in Com putational Kinematics. We understand here under this term that branch of kinematics research involving intensive computations not only of the nu merical type, but also of symbolic as well as geometric nature. Research in kinematics over the last decade has been remarkably ori ented towards the computational aspects of kinematics problems. In fact, this work has been prompted by the need to answer fundamental questions such as the number of solutions, whether real or complex, that a given problem can admit as well as computational algorithms to support geo metric analysis. Problems of the first kind occur frequently in the analysis and synthesis of kinematic chains, when fine displacements are considered. The associated models, that are derived from kinematic relations known as closure equations, lead to systems of nonlinear algebraic equations in the variables or parameters sought. The algebraic equations at hand can take the form of multivariate polynomials or may involve trigonometric functions of unknown angles.

This book contains 26 papers presented at the NATO Advanced Research Workshop on "CAD Based Programming for Sensory Robots," held in IL CIOCCa, Italy, July 4-6, 1988. CAD based robot programming is considered to be the process where CAD (Computer Based) models are used to develop robot programs. If the program is generated, at least partially, by a programmer interacting, for example, with a computer graph i c d sp i 1 ay of the robot and its workce 11 env ironment, the process is referred to as graphical off-line programming. On the other hand, if the robot program is generated automatically, for example, by a computer, then the process is referred to as automatic robot programmi ng. The key element here is the use of CAD models both for interact i ve and automat i c generat i on of robot programs. CAD based programmi ng, therefore, bri ngs together computer based model i ng and robot programmi ng and as such cuts across several discipl ines including geometric model ing, robot programming, kinematic and dynamic modeling, artificial intelligence, sensory monitoring and so-on.

Recently, research in robot kinematics has attracted researchers with different theoretical profiles and backgrounds, such as mechanical and electrica! engineering, computer science, and mathematics. It includes topics and problems that are typical for this area and cannot easily be met elsewhere. As a result, a specialised scientific community has developed concentrating its interest in a broad class of problems in this area and representing a conglomeration of disciplines including mechanics, theory of systems, algebra, and others. Usually, kinematics is referred to as the branch of mechanics which treats motion of a body without regard to the forces and moments that cause it. In robotics, kinematics studies the motion of robots for programming, control and design purposes. It deals with the spatial positions, orientations, velocities and accelerations of the robotic mechanisms and objects to be manipulated in a robot workspace. The objective is to find the most effective mathematical forms for mapping between various types of coordinate systems, methods to minimise the numerical complexity of algorithms for real-time control schemes, and to discover and visualise analytical tools for understanding and evaluation of motion properties ofvarious mechanisms used in a robotic system.

The trends and progress attained in computational kinematics over a broad class of problems are grouped into six parts describing the main themes: kinematics algorithms, discussing kinematics problems in light of their solution algorithms; kinematics of mechanisms, studying problems related to specific mechanisms; singularities; workspace, discussing the determination of the workspace of given mechanisms; parallel manipulators; and motion and grasp planning, touching on computational geometry. The volume contains a representative sample of the most modern techniques available for kinetics problems, including techniques based on advances in algebraic geometry. Researchers, graduate students and practising engineers in work relating to kinematics, robotics, machine design and computer science should find this work useful.

Recently, research in robot kinematics has attracted researchers with different theoretical profiles and backgrounds, such as mechanical and electrica! engineering, computer science, and mathematics. It includes topics and problems that are typical for this area and cannot easily be met elsewhere. As a result, a specialised scientific community has developed concentrating its interest in a broad class of problems in this area and representing a conglomeration of disciplines including mechanics, theory of systems, algebra, and others. Usually, kinematics is referred to as the branch of mechanics which treats motion of a body without regard to the forces and moments that cause it. In robotics, kinematics studies the motion of robots for programming, control and design purposes. It deals with the spatial positions, orientations, velocities and accelerations of the robotic mechanisms and objects to be manipulated in a robot workspace. The objective is to find the most effective mathematical forms for mapping between various types of coordinate systems, methods to minimise the numerical complexity of algorithms for real-time control schemes, and to discover and visualise analytical tools for understanding and evaluation of motion properties ofvarious mechanisms used in a robotic system.

This book is an integrated approach to kinematic and dynamic analysis. The matrix techniques presented are general and fully applicable to two- or three-dimensional systems. They lend themselves to programming and digital computation and can act as the basis of a usable tool for designers. Techniques have broad applicability to the design analysis of all multibody mechanical systems. The more powerful and more flexible the approach, and the less specialisation and reprogramming required for each application, the better. The matrix methods presented have been developed using these ideas as primary goals. Matrix methods can be applied by hand to such problems as the slider-crank mechanism, but this is not the intent of this text, and often the rigor required for such an attempt becomes quite burdensome in comparison with other techniques. The matrix methods have been extensively tested, both in the classroom and in the world of engineering industry.