Wireless sensors on rotating structures

Abstract

Wireless sensors capable of sensing, processing, and wireless communication can be useful for many monitoring purposes. Wireless sensor network testbeds to date have not considered sensors placed on fast moving structures.Fast rotating structures are commonly found in mechanical and vehicular systems, and the challenges of using wireless sensors on such structures have not been adequately addressed. The paper presents a testbed built of wireless sensors affixed to the spindle of a computer controlled lathe.By examining sensor communication errors with respect to rotation speeds and sensor locations, the study revealed an eminent dependency of packet error rates on rotation speeds, burstiness of bit errors, periodic received signal strengths, and dominance of multipath effects in the testbed. The study found the effects of non-uniform antenna gains, machine noise, hardware stability, and automatic gain control to be insignificant. While analytic derivation of Doppler effects with simplified assumptions has shown it to be insignificant, their coupled effects in a multipath environment remain to be studied further.