Vehicle over speed indicator

• US 20070213883A1
• Filed: 03/07/2006
• Published: 09/13/2007
• Est. Priority Date: 03/07/2006
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Kearns, Brian, Clarke, Bryan
• Granted Patent: US 7,551,991 B2
• Time in Patent Office: Days
• US Class Current: 701/1
• CPC Class Codes: B60T 7/22 initiated by contact of vehicle, e.g. bumper, with an external object, e.g. another vehicle , or by means of contactless obstacle detectors mounted on the vehicle
• CPC Class Codes: G07C 5/085 using electronic data carriers
• CPC Class Codes: G08G 1/16 Anti-collision systems road vehicle drive control systems for predicting or avoiding probable or impending collision otherwise than by control of a particular sub-unit B60W30/08

Abstract

A method is disclosed for providing an indication that a vehicle has exceeded a safe driving speed. The speed and position of an obstacle are combined with a driver reaction time to arrive at a safe maximum speed. The driver reaction time is predicted based not only on generic values as in known systems, but also on at least one scaling factor which can be, for example, a scaling factor which penalises increased driving duration, or driver age, or experience, or weather conditions.

Claims

1. A method for providing an indication that a vehicle has exceeded a safe driving speed, the method comprising the steps of:

measuring a current speed of said vehicle;

detecting an obstacle in the path of said vehicle and performing a measurement thereon;

calculating a predicted reaction time of a driver of said vehicle;

calculating a safe driving speed of the vehicle based on said predicted reaction time and said measurement performed on said obstacle; and

providing an indication when the measured current speed of the vehicle exceeds the calculated safe driving speed;

wherein the step of calculating a predicted reaction time of the driver comprises multiplying a generic driver reaction time by at least one scaling factor.

2. A method as claimed in claim 1, wherein the step of calculating said predicted reaction time further comprises determining said at least one scaling factor from a look-up table.

3. A method as claimed in claim 1, wherein the step of calculating said predicted reaction time comprises measuring a duration of a current driving session and selecting said at least one scaling factor based on the measured duration of the current driving session.

4. A method as claimed in claim 1, wherein the step of calculating said predicted reaction time comprises prompting the driver for an input and selecting said at least one scaling factor based on said input.

5. A method as claimed in claim 4, wherein said input is a parameter selected from a driver age, a driver age range, a driver experience level, a driver qualification and a driver license status.

6. A method as claimed in claim 1, wherein the step of calculating said predicted reaction time comprises retrieving a stored parameter from a memory device and selecting said at least one scaling factor based on said retrieved parameter.

7. A method as claimed in claim 1, wherein the step of calculating said predicted reaction time comprises detecting an environmental condition of the vehicle'"'"'s external environment and selecting a scaling factor based on said detected environmental condition.

8. A method as claimed in claim 5, wherein said environmental condition is selected from a visibility level, a weather condition, and an external light level.

9. An apparatus for providing an indication that a vehicle has exceeded a safe driving speed, the apparatus comprising:

a speed measurement device for measuring a current speed of said vehicle;

a sensor for detecting an obstacle in the path of said vehicle and performing a measurement thereon;

a reaction time calculator for calculating a predicted reaction time of a driver of said vehicle;

a processor programmed to calculate a safe driving speed of the vehicle based on said predicted reaction time and said measurement performed on said obstacle; and

an output for providing an indication when the measured current speed of the vehicle exceeds the calculated safe driving speed;

wherein the reaction time calculator operates to calculate a predicted reaction time of the driver by multiplying a generic driver reaction time by at least one scaling factor.

10. An apparatus as claimed in claim 9, the apparatus further comprising at least one look-up table stored in memory, wherein the at least one scaling factor is determined from said at least one look-up table.

11. An apparatus as claimed in claim 9, the apparatus further comprising a clock, the clock operable to measure a duration of a current driving session, the selection of the at least one scaling factor based on the measured duration of the current driving session.

12. An apparatus as claimed in claim 9, the apparatus further comprising an input device for the driver, the selection of the at least one scaling factor based on the input from the driver.

13. An apparatus as claimed in claim 12, wherein the input device comprises a card reader, the card reader operable to read a card encoded with the driving license details of a driver of the vehicle.

14. An apparatus as claimed in claim 12, wherein said input is a parameter selected from a driver age, a driver age range, a driver experience level, a driver qualification and a driver license status.

15. An apparatus as claimed in claim 9, the apparatus further comprising at least one sensor device operable to detect an environmental condition of the vehicle'"'"'s external environment, wherein selecting the at least one scaling factor is based on said detected environmental condition.

16. An apparatus as claimed in claim 15, wherein the sensor device comprises a light level sensor.

17. An apparatus as claimed in claim 15, wherein the sensor device comprises a rain sensor.

18. A method for providing an indication that a vehicle'"'"'s distance to an obstacle is less than the minimum required to safely avoid the obstacle, the method comprising the steps of:

measuring a current speed of said vehicle;

detecting an obstacle in the path of said vehicle and measuring the distance thereto;

calculating a predicted reaction time of a driver of said vehicle;

calculating a safe minimum distance to the obstacle from the vehicle based on said predicted reaction time and said measured distance to said obstacle; and

providing an indication when the measured current distance to said obstacle is less than the calculated safe minimum distance;

wherein the step of calculating a predicted reaction time of the driver comprises multiplying a generic driver reaction time by at least one scaling factor.

22. A method as claimed in claim 18, wherein the step of calculating a safe driving speed employs the following equation to perform said calculation:

$v_s=\sqrt{D_v^2<br><br>t_R^{\mathrm{\prime <br><br>2}}+2<br><br>\left(\frac{v_0^2}{2<br><br>D_0}+x_0\right)<br><br>D_v}-D_v<br><br>t_R^{\mathrm{\prime <br><br>}}$

wherein;

v_s is the calculated safe driving speed, t′

_R is the estimated driver reaction time, D_v is a deceleration value for the vehicle, V₀ is the speed of the obstacle,

X₀ is the distance to the object, and D₀ is the estimated maximum deceleration of the obstacle; and

wherein the estimated driver reaction time t′

_R is determined by the following formula;

t′

_R=t_R×

F

wherein t_R is a stored driver reaction time, and F is a scaling factor based on at least one of;

an elapsed driving time, a driver age metric, a visibility metric, and a driver experience metric.

19-19. -19. (canceled)

21. A method for providing an indication that a vehicle has exceeded a safe driving speed, the method comprising the steps of:

measuring a current speed of said vehicle;

detecting an obstacle in the path of said vehicle and measuring the distance to said obstacle and the speed of said obstacle;

determining an estimated maximum deceleration speed of said obstacle;

determining an estimated reaction time of a driver of said vehicle;

calculating a safe driving speed of the vehicle based on;

the current speed of said vehicle;

the distance to said obstacle;

the speed of said obstacle;

the estimated maximum deceleration of said vehicle

the estimated maximum deceleration of said obstacle; and

the estimated reaction time of said driver.

20. A method as claimed in claim 21, wherein said scaling factor F is calculated as F=F_d×

F_a×

F_v×

F_e, and wherein;

F_d is a driving time scaling factor, and F_a is a driver age scaling factor, F_v is a visibility scaling factor and F_e is an experience scaling factor.