Marco Ceccarelli

Fundamentals of mechanics of robotic manipulation

Preface 1: Introduction to Automation and Robotics 1.1 Automatic systems and robots 1.2 Evolution and applications of robots 1.3 Examples and technical characteristics of industrial robots 1.4 Evaluation of a robotization 1.4.1 An economic estimation 1.5 Forum for discussions on Robotics 2: Analysis of Manipulations 2.1 Decomposition of manipulative actions 2.2 A procedure for analyzing manipulation tasks 2.3 Programming for robots 2.3.1 A programming language for robots: VAL II 2.3.2 A programming language for robots: ACL 2.4 Illustrative examples 2.4.1 Education practices 2.4.1.1 Simulation of an industrial process 2.4.1.2 Writing with a robot 2.4.1.3 An intelligent packing 2.4.2 Industrial applications 2.4.2.1 Designing a robotized manipulation 2.4.2.2 Optimizing a robotized manipulation 3: Fundamentals of Mechanics of Manipulators 3.1 Kinematic model and position analysis 3.1.1 Transformation Matrix 3.1.2 Joint variables and actuator space 3.1.3 Workspace analysis 3.1.3.1 A binary matrix formulation 3.1.3.2 An algebraic formulation 3.1.3.3 A Workspace evaluation 3.1.4 Manipulator design with prescribed workspace 3.2 Inverse kinematics and path planning 3.2.1 A formulation for inverse kinematics 3.2.1.1 An example 3.2.2 Trajectory generation in Joint Space 3.2.3 A formulation for path planning in Cartesian coordinates 3.2.3.1 Illustrative examples 3.3 Velocity and acceleration analysis 3.3.1 An example 3.4 Jacobian and singularity configurations 3.4.1 An example 3.5 Statics of manipulators 3.5.1A mechanical model 3.5.2 Equations of equilibrium 3.5.3 Jacobian mapping of forces 3.5.4 An example 3.6 Dynamics of manipulators 3.6.1 Mechanical model and inertia characteristics 3.6.2 Newton-Euler equations 3.6.2.1 An example 3.6.3 Lagrange formulation 3.6.3.1An example 3.7 Stiffness of manipulators 3.7.1 A mechanical model 3.7.2 A formulation for stiffness analysis 3.7.3 A numerical example 3.8 Performance criteria for manipulators 3.8.1 Accuracy and repeatability 3.8.2 Dynamic characteristics 3.8.3 Compliance response 3.9 Fundamentals of Mechanics of parallel manipulators 3.9.1 A numerical example for CaPaMan (Cassino Parallel Manipulator) 4: Fundamentals of Mechanics of Grasp 4.1 Gripping devices and their characteristics 4.2 A mechatronic analysis for two-finger grippers 4.3 Design parameters and operation requirements for grippers 4.4 Configurations and phases of two-finger grasp 4.5 Model and analysis of two-finger grasp 4.6 Mechanisms for grippers 4.6.1 Modeling gripper mechanisms 4.6.2 An evaluation of gripping mechanisms 4.6.2.1 A numerical example of index evaluation 4.7 Designing two-finger grippers 4.7.1 An optimum design procedure for gripping mechanisms 4.7.1.1 A numerical example of optimum design 4.8 Electropneumatic actuation and grasping force control 4.8.1 An illustrative example for laboratory practice 4.8.1.1 An acceleration sensored gripper 4.9 Fundamentals on multifinger grasp and articulated fingers Bibliography Index Biographical Notes

A stiffness analysis for CaPaMan (Cassino Parallel Manipulator)

In this paper the 3 d.o.f. parallel manipulator, named as CaPaMan (Cassino Parallel Manipulator), is analysed in terms of stiffness characteristics. A formulation is presented to deduce the stiffness matrix as a function of the most important stiffness parameters of the CaPaMan architecture. The specific design of CaPaMan, which has been designed and built at the Laboratory of Robotics and Mechatronics in Cassino, Italy, helps to obtain closed-form analytical expressions. A numerical investigation has been carried out on the effects of design parameters by using the determinant of the stiffness matrix as a stiffness performance index and results are discussed in this paper.

A formulation for the workspace boundary of general N-revolute manipulators

Abstract An algebraic formulation is proposed to describe the workspace boundary of general N-R revolute open chain manipulators. The geometry of the generation process by revolving a figure about an axis has been used to deduce a recursive algorithm for the boundary of ring and hyper-rings by using the envelope concept. The workspace boundary is obtained from the envelope of a torus family which is traced by the parallel circles cut in the boundary of a revolving hyper-ring. The formulation is a function of the dimensional parameters in the manipulator chain and specifically of the last revolute joint angle, only. Some illustrative examples up to a 6R manipulator have been used to test the numerical procedure and they also provide remarks and show some peculiarities of the hyper-ring topology.

A Synthesis Algorithm for Three-Revolute Manipulators by Using an Algebraic Formulation of Workspace Boundary

A new synthesis algorithm for general three-revolute open chain manipulators is proposed making use of an algebraic formulation for the workspace boundary. This algebraic form of a synthesis model is used to formulate design equations and to discuss the number and the type of the multiple solutions.

A multi-objective optimum design of general 3R manipulators for prescribed workspace limits

Manipulator design can be conveniently expressed as a function of workspace requirements, since a fundamental feature of manipulators is recognized in workspace capabilities. In this paper a suitable formulation for the workspace has been used for the manipulator design, which has been formulated as multi-objective optimization problem by using the workspace volume and robot dimensions as objective functions, and given workspace limits as constraints. Additional constraints have been included to obtain manipulator sizes within practical values. The optimum design has been successfully tested by numerical examples, which have also proved the efficiency of using an algebraic formulation for the workspace of 3R manipulators.

A new 3 D.O.F. spatial parallel mechanism

This paper describes a new 3 D.O.F. parallel mechanism. The kinematic chain is composed of leg mechanisms containing articulated parallelograms and a peculiar connection with ball joints and prismatic guides has been utilised to obtain suitable direct kinematics and easy actuation. The engineering feasibility has been illustrated by investigating on the basic kinematic performances. Particularly, an analytical algorithm has been developed for displacement analysis which permits an easy workspace evaluation and path generation for trajectory and orientation capabilities.

Optimal design of CaPaMan (Cassino Parallel Manipulator) with a specified orientation workspace

CaPaMan (Cassino Parallel Manipulator) is a 3-Degree Of Freedom spatial parallel manipulator that has been designed at the Laboratory of Robotics and Mechatronics, in Cassino. In this paper we present a formulation for an optimum design for CaPaMan architecture when the orientation workspace is suitably specified.

Legged Robotic Systems

Walking machines have been attempted since the beginning of the technology of transportation machinery with the aim to overpass the limits of wheeled systems by looking at legged solutions in nature. But only since the last part of the 20-th century very efficient walking machines have been conceived, designed, and built with good performances that are suitable for practical applications carrying significant payload with relevant flexibility and versatility. In this chapter we have presented a survey of the variety of current solutions and prototypes of walking machines and we have illustrated fundamental characteristics and problems for their design and operation. The worldwide feasibility of walking machines is presented by discussing the activity at LARM: Laboratory of Robotics and Mechatronics in Cassino (Italy) as concerning with low-cost easy-operation solutions that can really make the walking machines available to non expert users for many applications.

Collision free path-planning for cable-driven parallel robots

In this study, a path-planning method that has been developed for serial manipulators is adapted to cable-driven robots. The proposed method has two modes. The first one is active when the robot is far from an obstacle. In this mode, the robot moves toward the goal on a straight line. The second mode is active when the robot is near an obstacle. During this mode, the robot finds the best way to avoid the obstacle. Moreover, an algorithm is presented to detect the collision between the robot and the obstacle. A similar algorithm is also presented to avoid the collision of the cables with an obstacle. Some simulation results are shown, which are then validated experimentally using a built 4-cable-driven parallel manipulator. Although the path obtained between the initial and final poses may not be the shortest possible one, it guarantees finding a path, when it exists, no matter how cluttered the environment is.

A Fairly General Algorithm to Evaluate Workspace Characteristics of Serial and Parallel Manipulators

Abstract In this paper a fairly general algorithm is proposed for the determination and evaluation of the workspace both for serial and for parallel manipulators. The procedure is based on a binary representation of the workspace and presents the possibility for a general evaluation of the shape and volume for robot workspace characteristics. Two examples are presented to show the practical feasibility of the proposed procedure and its practical results.