The research described in this report is a natural outgrowth of the work that was performed for Phase I-A of the National Highway Traffic Safety Administration’s (NHTSA) 1997 - 1998 Light Vehicle Rollover Research program. hen originally planned, NHTSA’s 1997 - 1998 Light Vehicle Rollover Research program was to consist of the Phase I research which was to develop a set of test manoeuvres to be used, and the Phase II research which was to use the Phase I manoeuvre set to measure the on-road, untripped, manoeuvre induced rollover propensities of a broad range of vehicles. However, preliminary analysis of the Phase I-A results revealed a number of issues that had to be resolved before the Phase II testing could begin. Therefore, the spring through fall of 1997 testing was renamed the Phase I-A research and additional testing, called the Phase I-B research, was performed during the fall of 1997 and the winter and spring of 1998. During the latter part of Phase I-A, it was decided that a steering controller should be purchased to provide more repeatable steering inputs. while waiting for delivery of the steering controller, several studies were conducted to evaluate driver, outrigger, and fuel level effects on test results. The objectives of Phase I-B Light Vehicle Rollover Research program were to: develop an understanding of driver variability, outrigger, and fuel level effects on test results; procure and implement testing with a programmable steering controller; and make a final determination of the manoeuvres to be selected for use in Phase II of the Light Vehicle Rollover Research program. There were several driver effects found, but these are greatly diminished with the use of the steering controller. based on limited results, the outriggers tend to dampen the response at higher frequencies and increase the response at lower frequencies. These changes appear to be relatively small especially for the normal outrigger case. Fuel level appears to have a negligible effect on test results. Four Vehicle Characterisation and five Untripped Rollover Propensity manoeuvres were developed for Phase II Research. The Four Vehicle Characterisation manoeuvres are: Pulse Steer, Sinusoidal Sweep, Slowly Increasing Steer, and Slowly Increasing Speed. The five Untripped Rollover Propensity manoeuvres are: J-Turn, J-Turn with Pulse, Fishhook #1, Fishhook #2, and Resonant Steer. (A)
Samenvatting