Erika Ottaviano

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.

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.

Identification of the Workspace Boundary Of a General 3-R Manipulator

In this paper an algebraic formulation is presented for the boundary workspace of 3-R manipulators in Cartesian Space. It is shown that the cross-section boundary curve can be described by a 16th order polynomial as function of radial and axial reaches. The cross-section boundary curve and workspace boundary surface are fully cyclic. Geometric singularities of the curve are identified and characterized. Numerical examples are presented to show the usefulness of the proposed investigation and to classify the design characteristics.

An optimum design procedure for both serial and parallel manipulators

Abstract Serial and parallel manipulators can be used in different manipulative tasks when their peculiarities in kinematic and dynamic behaviours are properly considered from the design stage. The basic performance in workspace, mobility constraints, and stiffness makes them alternative solutions and not competitive manipulator chains. Thus, it is convenient to deduce a common design procedure that considers common design criteria, but specific numerical evaluations. In this paper, a multi-objective optimization problem has been proposed to formulate a unique design procedure that takes into account the contradicting design optimality criteria in terms of suitable general algorithms for workspace volumes, Jacobian matrices, and compliant displacements. Numerical examples are reported to show not just the feasibility but also the numerical efficiency of the proposed formulations.

Singularity analysis of CaPaMan: A three-degree of freedom spatial parallel manipulator

CaPaMan (Cassino parallel manipulator) is a three-degree of freedom parallel mechanism that has been designed and built at the Laboratory of Robotics and Mechatronics in Cassino. In the paper a study of the configuration singularities of the CaPaMan manipulator is presented by considering two different methods: an algebraic formulation and a vector analysis. It is shown that a formulation can give singularity related to the failure of the kinematic model at particular configurations of the manipulator. It is also proved that this type of singularity can be avoided by a proper analysis of the problem.

Design improvements and control of a hybrid walking robot

In this paper design improvements and control algorithms are presented for a 2-DOF (Degree-Of-Freedom) hybrid leg-wheel walking machine. A prototype of a low-cost robot, which is capable of straight walking and steering with only two actuators, has been designed and built at LARM: Laboratory of Robotics and Mechatronics in Cassino. A control system has been developed in order to control the robots operation and to improve the prototypes behavior. The designed control system and simulation results have been reported to show the operation of the prototype.

Application of a 3-DOF parallel manipulator for earthquake simulations

In this paper a formulation and experimental results are presented for a novel application of a 3-degree of freedom (DOF) parallel manipulator to simulate point seismograms and three-dimensional (3-D) earthquake motion. The rigid body acceleration is analyzed to simulate real 3-D earthquakes. Furthermore, first experimental results are reported to analyze earthquake effects on scaled civil structures.

An application of CaTraSys, a cable-based parallel measuring system for an experimental characterization of human walking

In this paper, an application is presented of a cablebased parallel manipulator as measuring system for an experimental identification of human walking characteristics. Experimental results have been obtained by means of a new version of CaTraSys (Cassino Tracking System), which is a measuring system that has been designed and built at Laboratory of Robotics and Mechatronics (LARM) in Cassino, Italy. The new version of the CaTraSys system has been used to determine the trajectory of the human limb extremity during walking operation and furthermore the system is able to measure forces that are exerted by a limb. Experimental determination of articulation mobility is also presented with numerical and experimental results.

A Cable-Based System for Aiding Elderly People in Sit-to-Stand Transfer #

Abstract In this paper a 4-4 cable-based system is presented for an application of aiding elderly people or patients with disabilities at lower limbs, in standing up and sitting operations. Cable-based manipulators have very good kinematic and dynamic characteristics, and they also show other properties such as good transportability and low-cost construction, which make them also suitable for medical applications and rehabilitation. The proposed application is analyzed through a kinetostatic analysis and simulation of the manipulator. An experimental validation of the proposed application is presented by means of an existent prototype, which is called CALOWI (CAssino LOw-cost WIre robot) that is available at LARM in Cassino. A low-cost system for tension monitoring has been used to monitor the forces in the cables during the experimental tests.