Steering-wheel reversal driver alertness monitor

• US 4,104,621 A
• Filed: 08/19/1976
• Issued: 08/01/1978
• Est. Priority Date: 08/20/1975
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Matsumura, Akira, Yanagishima, Takayuki
• Primary Examiner(s): Swann, III, Glen R.
• Application Number:
  US05/715,827
• Time in Patent Office: 712 Days
• Field of Search: 340/279, 180/99
• US Class Current: 340/576
• CPC Class Codes: B60K 28/06 responsive to incapacity of driver
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: G08B 21/04 responsive to non-activity, e.g. of elderly persons G08B21/06 takes precedence
• CPC Class Codes: G08B 21/06 indicating a condition of sleep, e.g. anti-dozing alarms

Abstract

A driving assurance system for an automotive vehicle includes a steering detector which generates an electrical pulse in response to each angular movement of the steering wheel exceeding an arcuate extent less than 10°. A monostable multivibrator is connected to the steering detector to generate an output pulse in response to the first one of such pulses generated by a single steering operation so that the output from the multivibrator may represent a single steering operation. The output from the multivibrator is counted for a predetermined period to determine the state of the driver to operate a warning signal when he becomes incapacitated.

Claims

1. A driving assurance system for a wheeled vehicle having a steering wheel, comprising:

first means for detecting in use the oscillatory angular movement of a steering wheel of a wheeled vehicle to generate an electrical pulse for every angular movement exceeding a predetermined arcuate extent smaller than 10°

so that a series of pulses are generated when the angular movement exceeds an integral multiple of said arcuate extent, a monostable multivibrator connected to said detecting means to generate an output pulse in response to the first one of a series of said electrical pulses, said output pulse having a predetermined duration greater than the greatest possible interval between successive ones of said electrical pulses generated when the driver is normally operating the steering wheel, second means for generating a signal of which the magnitude increases in the presence of said output pulses, and third means for comparing at predetermined intervals the magnitude of said signal with a reference value to generate a warning signal if said signal is less than said reference value.

2. A driving assurance system as claimed in claim 1, wherein said arcuate extent is less than 5°

.

3. A driving assurance system as claimed in claim 1, wherein said detecting means comprises an arcuate light shield having a plurality of apertures arranged at a spacing smaller than 10°

, the light shield being mounted on the steering wheel for rotation therewith, a light source and a light detector mounted stationarily in opposed relation to the light source with the light shield disposed therebetween.

4. A driving assurance system as claimed in claim 1, wherein said second means comprises a binary counter, means for generating clock pulses to clear said binary counter at intervals.