WHEELED VEHICLE ROLLOVER PERFORMANCE TESTING SYSTEM

• US 20140298887A1
• Filed: 04/09/2013
• Published: 10/09/2014
• Est. Priority Date: 04/09/2013
• Status: Abandoned Application

• Current Assignee: Carl E. Nash
• Original Assignee: Carl E. Nash
• Inventors: Nash, Carl E.
• Application Number:
  US13/859,266
• Publication Number:
  US 20140298887A1
• Time in Patent Office: Days
• US Class Current: 73/12.04
• CPC Class Codes: G01M 17/06 Steering behaviour; Rolling behaviour
• CPC Class Codes: G01M 99/004 Testing the effects of speed or acceleration

Abstract

This invention is for a simple, dynamic test device and its use to assess a wheeled vehicle'"'"'s dynamic performance leading to a rollover including such conditions as a curb tripped rollover, a vehicle'"'"'s occupant restraint performance before and during the first roll, the motion of the vehicle'"'"'s occupants before and during a rollover, and the vehicle'"'"'s occupant protection performance in a rollover including its roof crush resistance. It does so by carrying a vehicle over a horizontal circular path at a speed sufficient that the centrifugal force on the vehicle will cause it to roll. The device provides unique, repeatable test conditions leading to a rollover as well as during the rollover. The device can also be used to test an object by subjecting it a high level of acceleration, force, and yawing motion about orthogonal vectors.

Claims

1. A rotating dynamic rollover test device consisting of a central, vertical axis firmly embedded in the earth to which arms are attached through a hub and bearings such that they can rotate freely in a horizontal plane about the a central axis, with a platform attached firmly to the arms or through hinges at the outboard ends of the arms, that is capable of carrying a wheeled vehicle, and with support wheels under and/or in front of and behind the platform to carry the load placed on the platform over a smooth, circular, level track over which the support wheels ride.

2. The device of claim 1 with power to move the platform in a horizontal circle provided by an engine or motor driving through the support wheels or by other means including directly to the platform or its arms using pneumatic, hydraulic, or electric power applied through belts or cables and pulleys. The power is sufficient to accelerate the platform and a test vehicle to a speed at which an object on the platform is subjected to a centrifugal force (velocity squared divided by radius) in excess of 1.5 times the acceleration of gravity:

an amount sufficient to induce a rollover of most wheeled vehicles.

3. The dynamic rollover test device for wheeled vehicles of claims 1 and 2 such that the vehicle being tested is essentially complete as it would be normally used and is not permanently attached to or encumbered by any significant carriages or frames that are not an inherent part of the vehicle.

4. The device of claims 1 and 2 to test a wheeled vehicle for its:

dynamic stability and resistance to rolling over, the motion of occupants of the vehicle before and during the first roll, performance of the vehicle'"'"'s occupant restraint systems before and during a rollover, roof crush resistance when the vehicle'"'"'s roof strikes the ground during a rollover, and the vehicle'"'"'s occupant protection capabilities under rollover conditions, and to test any component or system that requires a combination of yaw and longitudinal and lateral acceleration, the vectors of which are orthogonal.

5. A method for conducting tests of wheeled vehicles to measure and assess their stability and rollover propensity;

and their occupant motion, occupant restraint performance, occupant compartment integrity, and their occupant protection characteristics under pre-roll and rollover conditions using the device of claims 1, 2, and 4;

comprising the steps, for each test, of;

a. installing a test vehicle on the platform, with or without surrogate occupants, and temporarily securing it through quick release devices to the platform;

b. installing instrumentation and video equipment to measure and document the performance factors listed above;

c. applying power to the platform and thus to the vehicle to accelerate them to a speed sufficient to initiate the vehicle'"'"'s rollover;

d. releasing the vehicle such that it will slide off the platform with its outboard wheels leaving the platform first;

falling toward the ground and inducing roll motion as they drop, and striking the ground to further the rollover of the vehicle;

e. documenting the vehicle'"'"'s dynamic behavior and its occupant'"'"'s motion and interaction with the occupant restraints prior to and during the vehicle'"'"'s rollover,

f. measuring and documenting the vehicle'"'"'s impacts with the ground of impact surface including the deformation of its occupant compartment as the vehicle rolls and travels laterally across that surface; and

g. permitting the vehicle to come to a stop or arresting the vehicle before it undergoes a second roll.

6. The method and purpose of claim 5 for conducting tests of wheeled vehicles except that for a test curbs or other impediments are initially placed on the platform outboard of the test vehicle to induce a rollover on the platform so that the vehicle rolls over onto an impact platform or the ground.

7. For the case where the platform carrying the vehicle is attached by hinges to the control arms, the method and purpose of claims 5 except that once the platform reaches a pre-determined speed, the rollover is initiated by permitting platform and vehicle to roll about the platform'"'"'s hinges.

8. The method and purpose of claims 5 and 6 for conducting tests of wheeled vehicles except that when a vehicle is installed on the platform, restraining tethers are placed loosely around the vehicle such that when it begins to roll, the tethers prevent it from rolling more than approximately 45°

and therefore prevent it from completing the rollover. In this test, a vehicle'"'"'s pre-roll dynamics, the motion of an occupant at the beginning of a roll, and the performance of the occupant restraints—

particularly deployable restraints—

are documented and recorded; and

the vehicle can be returned to the platform for additional tests. This mode of operation can also be used to check the operation of the system without damaging the test vehicle before conducting a destructive test of the type described in claims 5 and 6.

9. The device of claims 1 and 2 for conducting tests of physical items such as vehicle components such as seats and restraint systems wherein the item is subjected to a high level of acceleration, to a force in an orthogonal direction as it undergoes a yawing motion about an axis that is orthogonal to the acceleration and force vectors.