Drowsiness alarm system for a vehicle
US4450438A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 5, 1981 |
| Grant date | May 22, 1984 |
| Priority date | — |
| Expiry date | Oct 5, 2001 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60W2540/18
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
According to the present invention there is provided a drowsiness alarm system which comprises: (a) a steering angle pulse generation circuit which produces first and second angle pulses at respective output terminals whenever the steering wheel is rotated clockwise and counterclockwise, respectively, through an angle equal to a predetermined angular increment; (b) curved road detection circuit responsive to the first and second steering pulses which counts the number of the first and second steering pulses separately and detects whether the vehicle travels on a curved road depending on whether the counted number of either of the first and second steering pulses reaches a first predetermined number within a predetermined period of time or depending on whether the difference of the counted number between the first and second steering angle pulses reaches a second predetermined number within the predetermined period of time; (c) a first counting circuit which counts the number of the first and second steering angle pulses within the predetermined period of time and outputs a first alarm signal whenever the counted number reaches a third predetermined number; (d) a second counting cir…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.