The Effects of Design Parameters on the Workspace of a Turin Parallel Robot

In this paper an investigation is carried out to determine topologi cal and design characteristics of the workspace of a Turin parallel robot named TuPaMan. We propose a procedure for the dimensional design of the device components. We mainly emphasize the motion capability of parallel robots, whose mechanical design may be scaled with respect to existing prototypes, by means of a characterization of the TuPaMan workspace. Additionally, orientation capability of the robot is evaluated through determining the workspace for a given orientation of the movable plate. The numerical results of the effects of the design parameters and the robot's workspace constraints are provided as three-dimensional plots and cross-sections of the most interesting workspaces. Finally, a parametric analysis is carried out as a function of the device size, using the overall dimensions and the area of the middle cross-section of the workspace as synthetic performance indices.

Design and Validation of Force Control Loops for a Parallel Manipulator

This paper addresses problems for design and validation of force control loops for a 3-DOF parallel manipulator in drilling applications. In particular, the control design has been investigated for a built prototype of CaPaMan2bis at LARM (Laboratory of Robotics and Mechatronics of Cassino). Two control loops have been developed, each one with two types of controllers. The first one is a Constrained Control Loop, which limits the force that is applied to an object to stay below a given value. The second one is a Standard Control Loop with external force feedback, which keeps the force at a given value. The control loops have been implemented on CaPaMan2bis by a Virtual Instrument in LABVIEW Software. CaPaMan2bis has been attached to a serial robot to make dynamic tests. The results of the experimental tests show the effectiveness and quick response of both algorithms after a careful calibration process.