Method of determining the driver's sufficient alertness to drive a motor vehicle safely

• US 4,005,398 A
• Filed: 03/19/1975
• Issued: 01/25/1977
• Est. Priority Date: 04/16/1974
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Inoue, Naohiko, Yanagishima, Takayuki, Nakamura, Hiromichi, Fukasawa, Noburu
• Primary Examiner(s): Swann, III, Glen R.
• Application Number:
  US05/559,922
• Time in Patent Office: 678 Days
• Field of Search: 340/279, 180/99
• US Class Current: 180/272
• CPC Class Codes: A61B 5/18 for vehicle drivers or machine operators
• CPC Class Codes: B60K 28/06 responsive to incapacity of driver

Abstract

A constant voltage developed by a constant voltage generator is integrated, and the integrated voltage is applied to a voltage comparator. A standard voltage is applied to a voltage controller, which includes a sensor responsive to vehicle operating conditions, to control the level of the standard voltage to indicate the degree of driver alertness necessitated by the vehicle operatingconditions. The controlled standard voltage is also applied to the voltage comparator, and when the integrated voltage exceeds the controlled standard voltage the comparator develops a warning signal output. A warning device receives the warning signal and is thereby rendered operative in order to alert the driver.

Claims

1. A method of determining driver'"'"'s alertness and warning the driver when his alertness falls below a preselected level while driving a vehicle, which comprises the steps of:

generating a first signal having a preselected constant potential;

integrating the first signal with respect to time;

generating a second signal which is a standard potential indicative of a minimum allowable limit of the driver'"'"'s degree of alertness;

comparing the magnitudes of the integrated first and the second signals;

warning the driver when the magnitude of the integrated first signal exceeds that of the second signal; and

sensing the driver'"'"'s sufficient alertness for safe driving to reset the integrating and to stop the warning.

2. A method as claimed in claim 1, further comprising the step of:

stopping automatically the warning after a lapse of a preselected time interval.

3. A method as claimed in claim 1, further comprising the step of:

stopping the warning only when the driver switches off the ignition switch of the vehicle.