Assessment of Magnetohydrodynamic Angular Rate Sensors in Measuring Ankle Rotations During Vehicle's Crash Tests 2000-01-0609

While testing vehicles for crash, particularly the offset frontal crash mode, new devices and techniques are needed to enhance the ability to measure rotations of certain vehicle components and dummy parts (or joints). The reason for this new demand is that the capabilities of existing techniques or devices in measuring rotations of small masses in confined areas are limited. Examples of the desired measurements are the rotations of dummy's feet and tibias as well as the rotations of the vehicle's toe-board during intrusion. These measurements help to understand dummy's ankle loads as a result of different intrusion rates. Furthermore, having these measurements is very beneficial to the validation of the computer models used in simulating the behavior of dummy's lower extremities in high intrusion crashes.

Recent research demonstrated the use of an angular rate sensor, based on magnetohydrodynamic principles, on Hybrid-III dummies and cadavers. Because of the sensor's compactness in size and light weight, it can be used in vehicle crash tests in areas where conventional measuring techniques such as high speed films is impractical.

This report describes an experimental investigation of the capability of Magnetohydrodynamic (MHD) Angular Rate Sensor (ARS) in measuring the ankle rotations during vehicle crash tests. It explains how the sensors were added to the dummy's feet and tibias and how they were used to identify the responses' characteristics of these segments during vehicle crashes. In addition, it discusses an experimental approach of setting up simplified laboratory impact tests to assess the sensors capabilities.