Automatic vehicle speed limiting system

Abstract

A vehicle speed control system is disclosed. The system is carried by a vehicle for automatically controlling the vehicle speed in response to external light signals. First and second light detecting means, e.g. photodetectors, detect first and second types of light signals, respectively. These signals are preferably light reflected from different colored hands on a pavement over which the vehicle passes. The first type of signal representing a highest permissible speed limit for the vehicle, the second type representing a lower, predetermined speed limit. A speed governing means, preferably a solenoid-controlled vacuum governor, is selectively energizable for limiting the vehicle speed. Circuitry of the system is responsive to the second light detecting means for energizing the speed governing means thereby to limit the vehicle speed to the predetermined limit. This circuitry is responsive to the first light detecting means to deenergize the governing means, thus permitting highest permissible speed of the vehicle. As a method of controlling vehicle speed in response to external light signal, the disclosure contemplates detecting a light signal representing the predetermined speed limit, converting this detection into a digital number representative of the speed limit, generating a speed signal representative of the vehicle's actual speed, and electronically comparing the digital number with the speed signal. Finally, the method involves limiting the speed of the vehicle propulsion motor if the speed signal incipiently exceeds the digital number.

Dependencies are inferred from the claim text.