Friction Modeling and Slip Estimation of the Spiral Zipper Friction-Driven Prismatic Actuator

Abstract

Spiral Zipper is a novel prismatic actuator which utilizes a flexible ABS band to extract a length-changeable cylindrical tube. It is driven by an omnidirectional wheel exerting a frictional torque on the band. The tube is subjected to a frictional torque on its cylindrical inner surface from the omnidirectional wheel. This mechanism allows minimized processing for the surface on the band, but the motion of the band is not fully constrained because of the slip. This paper addresses methods of the slip expectation prior to the control system design. A dynamics model considering the flexibility of the Spiral Zipper band was established, and simulations on the dynamic model and validation experiments were conducted. The relationship between the angular velocities of the wheel and the band showed similar tendency to the experiments results. These results can be basis for establishing the control model of the Spiral Zipper.