Design of a Planar Cable-Driven Parallel Robot for Non-Contact Tasks

Abstract

Cable-driven parallel robots offer significant advantages in terms of workspace dimensions and payload capability. Their mechanical structure and transmission system consist of light and extendable cables that can withstand high tensile loads. Cables are wound and unwound by a set of motorized winches, so that the robot workspace dimensions mainly depend on the amount of cable that each drum can store. For this reason, these manipulators are attractive for many industrial tasks to be performed on a large scale, such as handling, pick-and-place, and manufacturing, without a substantial increase in costs and mechanical complexity with respect to a small-scale application. This paper presents the design of a planar overconstrained cable-driven parallel robot for quasi-static non-contact operations on planar vertical surfaces, such as laser engraving, inspection and thermal treatment. The overall mechanical structure of the robot is shown, by focusing on the actuation and guidance systems. A novel concept of the cable guidance system is outlined, which allows for a simple kinematic model to control the manipulator. As an application example, a laser diode is mounted onto the end-effector of a prototype to perform laser engraving on a paper sheet. Observations on the experiments are reported and discussed.

Impact of Tuned Mass Dampers and Electromagnetic Tuned Mass Dampers on Geometrically Nonlinear Vibrations Reduction of Planar Cable Robots

“…Tese kind of vibrations are present in planar confgurations, where one direction does not have a direct mechanical restriction. A design of this kind of CDPR can be seen in [12]. Tis kind of vibration and this confguration of a CDPR were the study cases in this research.…”

Cable-Driven Parallel Robot Actuators: State of the Art and Novel Servo-Winch Concept

“…They are parallel robotic manipulators where rigid links are replaced by extendable cables. The latter are wound and unwound by linear or rotational actuation units (called winches in the following) and routed using guidance devices toward a shared end-effector (EE in short), on which they are attached in a parallel fashion [1].…”

“…Only in the nineties the RoboCrane ® was introduced [15]: this equipment was the first to allow both position and orientation of its EE to be automatically controlled with six cables. Since then, numerous applications have been proposed and successfully implemented by researchers: large-scale additive manufacturing [16], laser-based manufacturing [1], contour crafting [17], marine handling systems [18], warehouse retrieval systems [6], large-scale handling systems [19,20], facade cleaning [21] and installation [7] systems, motion simulators [22], large-aperture telescopes [23], measurement devices [24][25][26][27], rehabilitation devices [28], and haptic interfaces [29].…”

“…For industrial applications, guidance systems are usually a combination of fixed and swiveling pulleys [1], whose geometry and installation configuration are dictated by geometric and loading conditions of the operation (many research prototypes have even simpler guidance systems, such as eyelets where cables may slide through [38]). Conversely, the design of the actuation unit is driven by application requirements in terms of rated power, cable tension, and speed, but also by the requirements of the control system.…”

Design and Kinetostatic Modeling of a Cable-Driven Schönflies-Motion Generator

“…The peculiarity of this robot is the arrangements of the cables around the MP. Indeed, the six cables of the proposed Cable-Driven Schönflies Motion Generator (CDSMG) are arranged in such a way that three parallelograms cable structures are formed to constrain the rotational motions of the MP [11][12][13][14][15]. One of the six cables is wound on two drums at its two ends, making one cable loop used to actuate the rotational motion of the pulley embedded in the MP.…”