Patent ID: 6362749
Filing Date: 2002-03-26
Classification: G08G

Abstract:
A vehicle detection system comprising, in combination:a sound signal-producing unit in an emergency vehicle, the sound signal-producing unit including: a sound generator for producing and transmitting a sound signal away from the emergency vehicle; a switch for controlling the operation of the sound generator; a siren connected to the switch; a logic gate connecting the sound generator to the siren and the switch for activating the sound generator corresponding to the position of the switch; a sound signal detection unit in a vehicle, the sound signal detection unit including: at least one sound transducer connected to the existing vehicle electrical system for detecting sound signals and producing an electric current; a signal comparator connected to the sound transducers for comparing the currents from the transducers to preprogrammed patterns; a signal strength detector connected to the signal comparator for activating a circuit corresponding to the currents from the signal comparator; a signal strength change detector connected to the signal strength detector and to the signal output encoder for completing a circuit corresponding to the currents from the signal strength detector; a signal output encoder connected to the signal strength detector and the signal strength change detector for constructing an encoded signal according to the currents from the signal strength detector and the signal strength change detector; a transmitter connected to the signal output encoder and to the vehicle electrical system for transmitting the encoded signal from the signal output encoder through an antenna; a display unit in the vehicle, the display unit including: a receiver connected to a battery and an antenna for receiving the encoded signal from the transmitter of the sound signal detection unit; a signal comparator connected to the receiver for comparing the encoded signal to known patterns and activating a circuit; at least one illumination device connected to the signal comparator and the battery for indicating the detection of the signal; and an oscillator connected between the illumination device and the battery to produce a flashing effect in the illumination device.