CA2032861A1 - Single wire, infrared, randomly reflected, automotive multiplexing system - Google Patents

Abstract

A vehicular, infrared, multiplexing system controlling various vehicular or automotive electrical function loads, such as, for example, lights, window motors, seat motors, door locks, engine start and the like, wherein control and sensing signals are transmitted within the interior of the vehicle by randomly reflected, infrared radiation or similar optical energy carrying electronically intelligible information. The infrared system does not require or rely on direct, line-of-sight or controlled reflection or a continuous optical circuit, but instead relies on randomly reflected, scattered, diffused, infrared radiation reflected from various interior surfaces of the vehicle, including, for example, practically all interior surfaces, such as the windshield, side and rear windows, seats, headliner, instrument panel, rear window, door trim panels, etc. One or more central transmitter/receivers are included in the vehicle's interior, including the instrument panel using the windshield, the rear of the center console using the headliner, and/or in the rear package deck using the rear window. A serial, multiplex transmission with half-duplex, serial data bi-directionally format is used, including a sync code alerting the load devices of transmission start, a unique vehicle code (e. g., the VIN), the central control unit's MUX command, the central unit's cyclic redundancy error checking code, remote unit address, remote's MUX response, and remote's cyclic redundancy code.
Because all system information is transmitted by infrared, only one wire, used for twelve volt DC power, is required to each of the load units, with the vehicular chassis serving as ground return.