A Crawling Based Locomotive Mechanism Using a Tiny Ultrasonic Linear Actuator (TULA)

摘要

A crawling based locomotive mechanism for inspectionrnof small sized pipes is developed by using a tiny ultrasonicrnlinear actuator. In case of piezo material based actuators, it isrnknown that they have small displacement with high voltagernsupply. In order to overcome the limitation of common piezornactuators, the impact based piezo actuator(TULA) has beenrndeveloped to realize long stroke up to 11 mm. By usingrnTULA, we develop a crawling locomotive mechanism.rnPreviously reported locomotive mechanisms such asrnearthworm-like and inchworm-like mechanism can notrnrealize continuous motion but move with step-wise motionrnsince they have clamping and elongation sequence forrnmovement. Therefore, long time loss for movement of onernstroke is inevitable. In this crawling mechanism, nearlyrncontinuous motion is achieved by using both directions ofrnactuating forces. Owing to the light weight and the simplernstructure of the actuator, the crawling based locomotivernmechanism has simple design with 9mm diameter, 40mmrnlength and 1.1g weight. It shows 9.2mm/s in 18.5mm insiderndiameter of a pipe regardless of the pipe's tilting angle.