Vehicle driver alertness apparatus monitoring steering wheel oscillations

• US 4,017,843 A
• Filed: 02/05/1976
• Issued: 04/12/1977
• Est. Priority Date: 02/07/1975
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Yanagishima, Takayuki
• Primary Examiner(s): Swann, III, Glen R.
• Application Number:
  US05/655,580
• Time in Patent Office: 432 Days
• Field of Search: 340/279, 340/52 R, 340/53, 180/99
• US Class Current: 180/272
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: G08B 21/06 indicating a condition of sleep, e.g. anti-dozing alarms

Abstract

Steering wheel oscillations are detected and a first signal generated for each predetermined number of oscillations. A ramp generator is reset by each first signal and, if its output reaches a preset value, a comparator generates a second signal to indicate excessive time between first signals. An up-down counter is counted up by each first signal and down by each second signal. A comparator compares the contents of the counter with a present number and generates a third signal when the number in the counter falls below the present number. A timer consisting of an integrator and comparator generates a forth signal when the third signal has been present for a predetermined time. The forth signal causes an alarm device to alert the driver.

Claims

1. A vehicle safety apparatus comprising:

means for detecting movements associated with the driving activity of a vehicle driver to produce a first signal in response to a predetermined number of said movements;

means for producing a second signal when the interval between successive first signals is greater than a predetermined period of time;

an integration circuit for producing a third signal of which the magnitude increases in response to the first signal and decreases in the presence of the second signal;

means for producing a fourth signal when the magnitude of the third signal reaches a preset value; and

a utilization circuit responsive to the fourth signal to alert the vehicle driver.

2. A vehicle safety apparatus as claimed in claim 1, wherein said detecting means comprises means for generating a pulse in response to each movement and means for counting said pulses to produce said first signal when said predetermined number is reached.

3. A vehicle safety apparatus as claimed in claim 1, wherein said movements are derived from the oscillatory movements of a vehicle steering wheel.

4. A vehicle safety apparatus as claimed in claim 1, wherein said means for producing a second signal comprises a ramp generator and a comparator whose input is connected to the output of said generator, said comparator comparing the magnitude of a signal from said generator with a preset value to produce said second signal when the preset value is attained.

5. A vehicle safety apparatus as claimed in claim 1, wherein said integration circuit comprises an up-down counter having up-counting and down-counting modes, said up-down counter being arranged to receive the first signal to permit it to operate in the up-counting mode and to receive the second signal to permit it to operate in the down-counting mode.

6. A vehicle safety apparatus as claimed in claim 1, wherein said means for producing a fourth signal comprises a comparator which compares the magnitude of the third signal with a preset value to produce said fourth signal when the third signal is below the preset value.

7. A vehicle safety apparatus as claimed in claim 1, wherein said utilization circuit comprises a timing circuit responsive to the fourth signal to generate an alarm signal when said fourth signal has persisted for a predetermined time, and means for attracting the attention of said driver in response to said alarm signal.