Position prediction of viscoelastic rope on traction sheave with rope-slip model

Abstract

With the increasing demand for high-rise building management, robots are being developed that use fiber ropes to move over façade of buildings. As fiber ropes deform under a load, predicting the exact position of the robot with a winch is difficult. In this study, we developed and verified a method for predicting the position of the load suspended on a rope by modeling the characteristics of a rope showing viscoelastic behavior. The rope slip amount was calculated using the Firbank model for predicting the friction on the sheave. When ascending or descending the load with the sheave, the position was predicted using a quasi-static analysis method using the Burgers model and a dynamic analysis method using the Kevin–Voigt model. A tensile test was conducted to model the rope, and the test results verified the model. In the position prediction experiment, the real-time position of the load was measured and compared with the values simulated based on the Burgers and the Kelvin–Voigt models. The Burgers model and Kelvin–Voigt model exhibited mean errors to 4.3% and 1.09%, respectively.