ABSOLUTE ANGULAR POSITION SENSING SYSTEM BASED ON RADIO FREQUENCY IDENTIFICATION TECHNOLOGY

摘要

A system for determining the position of a rotating wheel using RFID. In one embodiment, the system includes a position sensing wheel mounted to one or both of a crankshaft and a camshaft in the engine. A plurality of RFID tags are disposed at predetermined intervals around the wheel, and an RFID transceiver is positioned proximate the wheel. As the wheel rotates, the RFID transceiver transmits a signal that interrogates the RFID tags, which then transmit a coded signal to the transceiver identifying the wheel's position relative to the transceiver. Therefore, regardless of the position of the wheel, the RFID transceiver can interrogate the closest RFID tag and immediately know the position of the engine so that an engine controller can provide fuel and spark to the cylinders as soon as possible.