Design and analysis of novel friction controlling mechanism with minimal energy for in-pipe robot applications

In-pipe wheeled robots require friction on the wheels to maintain traction. Ability to vary this friction is highly desirable but conventionally used linkage mechanism is not suitable for it. This paper presents a novel mechanism generating adjustable friction with minimal energy consumption for in-pipe robots. The mechanism uses permanent magnets to achieve the objective. An appropriate model for the system is also presented and discussed. The paper identifies the important design parameters, and more importantly establishes the relation between the design parameters and the system's performance. In addition, a prototype of the mechanism was designed, fabricated and tested for validation.