FMVSS 201U Testing - Vehicle Targeting Using both Manual and Computer-Aided Methods 1999-01-0434
In April 1997, the National Highway Traffic Safety Administration (NHTSA) issued a final rule amending Federal Motor Vehicle Safety Standard (FMVSS) 201U. This rule specifies improved upper interior head impact protection requirements for all vehicles with a GVWR of 10,000 lbs or less (and buses under 8,500 lbs). The purpose of this new safety standard is to afford occupants within a vehicle additional protection to reduce the likelihood of severe head injury regardless of the type of vehicle collision. As with past standards, the NHTSA provided a test procedure to be used for compliance testing. This procedure includes information regarding set-up, targeting, testing, and data analysis. The targeting procedure, which locates all applicable target points on the upper interior trim of a vehicle, was written without being vehicle-specific. This test procedure is one of the most complex and time-consuming testing protocols developed in recent years. The “targeting” procedure is the focus of this paper. The NHTSA test procedure calls out for measurements during the targeting procedure to be made manually without relying on OEM-specified target locations. Though this method is used currently, a second test method involving the use of a Coordinate Measurement Machine (CMM) in conjunction with some manual measurements may be a better alternative. This paper will present background information on FMVSS 201U testing, describe the vehicle targeting process in detail, provide data which compares the manual targeting method to a computer-aided targeting method using a CMM, and discuss the potential advantages of a computerized targeting procedure.