A Deployable Cable-Driven Parallel Robot With Large Rotational Capabilities for Laser-Scanning Applications

Abstract

This paper presents a novel Cable-Driven Parallel Robot dedicated to laser-scanning operations. The proposed device can inspect low-accessibility environments thanks to a self-deployable end-effector, which can be inserted in a closed container through very small access areas, such as hatches, pipes, etc. The reconfigurable end-effector is suspended and actuated by extendable cables, and is equipped with an optical mirror, which is used to deflect a laser beam produced by a frame-fixed laser distance sensor. Thanks to its large orientation capabilities, the machine can record the position of points belonging to a large portion of the surface to be scanned, primarily by tilting and panning the end-effector. The robot is equipped with a frame-orientation calibration device, which can align the machine frame to earth gravity before operation. The robot capabilities are validated by a prototype, which experimentally reconstruct benchmark surfaces.

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

“…There are several solutions in the literature to achieve such desired design requirements (Figure 1). It is possible to rototranslate the drum [16,37,38] so that the cable exit point from the drum, and consequently its direction, is kept fixed with respect to the winch frame, while the cable is coiled and uncoiled. This is usually achieved by employing screw/nut joints to convert the rotational motion of the motor into rotational and translational motion of the drum, and allowing the drum to translate by mounting it on a passive prismatic joint.…”

“…Eyelets allow for the approximate definition of a point and significant cable orientation, but cause high cable wear [40]. However, they are employed in many CDPRs thanks to their simplicity, and the possibly low geometrical error introduced, if the CDPR workspace is large [16,38,41]. Figure 2 shows the use of eyelets as proximal anchor points on the fixed frame of the CDPR prototype presented in [16].…”

“…In the second case, the robot geometry, the number and configuration of cables, and, consequently, additional design constraints are established by the final task. This is the case of the deployable CDPR in [16]: the suspended architecture and the EE self-deployability ensure the high orientational capability required for the laser scanning of low-accessibility environments. As an additional example, the storage-retrieval CDPR in [8] is equipped with eight cables, despite the planar nature of the robot task, in order to provide a suitable machine stiffness and prevent platform tilt.…”

Kinematic of 4SPRR-SPR parallel robots based on VQTAM

“…Y is the nearest neighborhood v i*n in of X in , and Z is the corresponding data point v i*n out , As shown in equations (20) and (21).…”

“…In addition, the cable-driven manipulators are a class of PMs, where the end-effector is displaced by means of servo-actuated extendable cables. 20 They have high ratio of payload to robot weight and a much larger workspace which is appropriate for camera positioning in sports stadiums and many others. 21 Arian Bahrami et al studied the optimal design of various forms of the cable-driven manipulators.…”