Tracking angular motion of dummy components, such as the head, is important in understanding body response during violent force exposures. This paper compares four methods of measuring angular motion of a Hybrid III dummy head during a series of tests using a horizontal accelerator sled and a head/neck pendulum. The Hybrid III head was instrumented with three orthogonal magnetohydrodynamic (MHD) angular rate sensors and with nine linear accelerometers arranged in a 3-2-2-2 array. The motion of the head was monitored using a Selspot optical target tracking system and a high speed video camera during the horizontal accelerator sled tests. A two-potentiometer device and a high speed camera were used to monitor the head motion during a series of head/neck pendulum flexion and extension tests. Software routines were written to calculate the head rotation and angular velocity from the head mounted sensors. Comparisons of the angular velocity and rotation, determined using the MHD, nine accelerometer array, and Selspot system, were made for each of the horizontal accelerator sled tests. For each pendulum test, the two-potentiometer data were differentiated to determine the angular velocity and these data were compared to the angular velocity determined using the MHD sensors and the nine accelerometer array. The angular rotation of the head from the three sensor technologies was also compared for each pendulum test. (A)
Abstract