A self-powered absolute shaft encoder based on triboelectric nanogenerator

Abstract

A rotary encoder is an important element for measuring the rotational motion in various mechanical systems. This paper proposes a self-powered absolute shaft encoder (SPASE) based on a triboelectric nanogenerator that enables absolute angle measurement and stable signal detection without additional circuits for signal processing by utilizing a voltage pumping method. SPASE was designed by separating the measurement function and the triboelectric power generation function and modularizing the parts that perform each function. A SPASE prototype with a size of ϕ42 mm × 50 mm was manufactured. It was experimentally confirmed that, in this prototype, a voltage of 182.7 V can be generated in the pumping module and that stable angle measurement with a resolution of 12° can be successfully conducted over a wide speed range from 40 to 2000 rpm in the sensing module. Furthermore, SPASE exhibits great applicability and flexibility as a self-powered absolute angle sensor because the pumping and sensing modules are separated and each module can be independently operated as needed. SPASE is expected to be used in various fields that require rotation monitoring without any external power sources.