Roadway curve advisory speed determination

• US 20030005765A1
• Filed: 06/08/2001
• Published: 01/09/2003
• Est. Priority Date: 06/08/2001
• Status: Active Grant

• Current Assignee: Brudis & Associates, Inc.
• Original Assignee: Brudis & Associates, Inc.
• Inventors: Ha, Nguyen, Milstead, Robert, Cross, Seward, Brudis, Tony
• Granted Patent: US 6,523,409 B2
• Time in Patent Office: Days
• US Class Current: 73/488
• CPC Class Codes: B60W 2420/00 Indexing codes relating to the type of sensors based on the principle of their operation
• CPC Class Codes: B60W 2422/00 Indexing codes relating to the special location or mounting of sensors
• CPC Class Codes: B60W 2520/125 Lateral acceleration
• CPC Class Codes: B60W 30/18145 Cornering
• CPC Class Codes: B60W 40/00 Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models
• CPC Class Codes: G08G 1/167 Driving aids for lane monitoring, lane changing, e.g. blind spot detection

Abstract

The advisory speed meter is used to determine the advisory speed for a highway curve or to provide data for use in determining the advisory speed for a highway curve. The meter determines and records the maximum lateral horizontal acceleration experienced by a vehicle and occupants while traversing a highway curve. The meter has been extensively tested on rural curves and on entrance and exit and connecting ramps between all types of highways. The process for determining an advisory speed for a curve is described. The advisory speed meter provides accurate, reproducible data for use in determining advisory speeds for highway curves.

Claims

1. An advisory speed meter for determining the maximum lateral horizontal acceleration in a vehicle comprising:

an accelerometer unit capable of sensing the lateral horizontal acceleration experienced in a vehicle,

the accelerometer unit mounted on the floor of the vehicle at the vehicle centerline,

the front of the accelerometer unit oriented toward the front of the vehicle,

the accelerometer unit mounted perpendicular to the vehicle floor, and

a meter unit capable of calculating and displaying the maximum lateral horizontal acceleration experienced by the vehicle,

the accelerometer unit connected by a connector cable to the meter unit.

2. The advisory speed meter of claim 1 wherein the accelerometer unit is mounted to the floor of the vehicle by a pedestal which clamps on a swivel ball mounted on the accelerometer and on a swivel ball mounted on the floor of the vehicle.

3. The advisory speed meter of claim 1 wherein the accelerometer unit further comprises a bubble level for use in mounting the accelerator unit perpendicular to the vehicle floor.

4. The advisory speed meter of claim 1 wherein the meter unit has a visual display of the maximum lateral horizontal acceleration experienced by the vehicle.

5. The advisory speed meter of claim 1 wherein the meter unit further comprises controls for initiating and termination the period for recording the maximum lateral horizontal acceleration experienced by the vehicle.

6. The advisory speed meter of claim 1 wherein the meter unit further comprises controls for calibrating the accelerator unit.

7. The advisory speed meter of claim 1 wherein the meter unit further comprises a control for resetting the meter after a maximum lateral horizontal acceleration has been displayed.

8. The process for determining the advisory speed for a curve in a roadway comprising the steps:

a. traversing the curve in a vehicle of specified type at a specified constant speed,

b. measuring the maximum lateral horizontal acceleration experienced by the vehicle while traversing the curve using a vehicle accelerometer,

c. repeating steps a. and b. at speeds differing from the speed in step a.,

d. determining the speed of traverse associated with a predetermined maximum lateral horizontal acceleration, and

e. designating the speed of traverse associated with a predetermined maximum lateral horizontal acceleration as the advisory speed for the curve.

9. The process of claim 8 wherein the specified type of vehicle is a compact-type car, standard-type sedan or a sports utility vehicle.

10. The process of claim 8 wherein the speed in step c. is faster than the speed in step a.

11. The process of claim 8 wherein the speed in step c. is about 5 miles per hour faster than the speed in step a.

12. The process of claim 8 wherein the predetermined maxiumum lateral horizontal acceleration is 0.28 g-ft/sec².

13. The process of claim 8 wherein the predetermined maxiumum lateral horizontal acceleration is less than or equal to 0.40 g-ft/sec².

14. The process of claim 8 wherein step e. is deleted and the following substitute step e. is substituted for step e.:

e. using the speed of traverse associated with a predetermined maximum lateral horizontal acceleration as one of several elements used in determining the advisory speed for a curve.

15. The process of claim 14 wherein the elements used in determining the advisory speed for a curve include pavement conditions, operating speeds, vehicle suspension systems, roadway gradients, surface friction factors, vehicle classifications, vehicle occupancy or highway gravitational forces.