An Experimental Test Bench for Cable-Driven Transmission

Abstract

Cable-driven transmissions are used widely in robotic applications. However, design variables and parameters of this kind of transmission remain under study, both analytically and experimentally. In this paper, an experimental test bench to evaluate the behavior of medium-low power pulley-cable transmissions is presented. The design of the test bench allows manipulating variables such as dimensions, external load, speed, and cable tension. The system consists mainly of a brushless direct current (DC) motor, two load cells to measure the mechanical reactive force in the motor, two dismountable pulleys, two drums, a perforated disk, and several masses that provide the load and the inertial load, and electronic modules to control the speed and position of the pulley. Special attention was paid to the calibration of the load cells, focused in compensating the effect of creep. Validation tests were carried out in order to evaluate the device design. Next, pilot experiments were performed to estimate the friction behavior in the transmission. Preliminary results suggest that the friction in the transmission is largely governed by the friction behavior of the bearings.

Static Friction in a Cable-Driven Transmission—Modeling and Identification of Load Effects

“…The determination of the friction behavior is carried out on the experimental test bench designed by Torres [35]. On the test bench, the transmission module is configured by a steel cable (a), a capstan system (b) and a pulley system (c).…”

“…This work addresses the determination of static friction in a cable-driven transmission, including the effect of a payload. The experiments are performed on a test bench designed and built for this purpose at Universidad Tecnológica de Pereira, in partnership with Universidad Nacional de Colombia [35]. The test bench is loosely based on the articulations of a Barrett WAM arm created at the Massachusetts Institute of Technology [36].…”