Ruth, R. and Muir, B., "Longitudinal Delta V Offset between Front and Rear Crashes in 2007 Toyota Yaris Generation 04 EDR," SAE Technical Paper 2016-01-1496, 2016, doi:10.4271/2016-01-1496.
Earlier research1 suggests there may be positive offset in the longitudinal G sensor in Toyota Corolla Gen 02 EDR’s. This research tests if a similar offset is present in Toyota Gen 04 EDR’s in the 2007 Yaris. A series of low speed forward and rearward collisions into a stationary vehicle were conducted. In addition to the installed vehicle ACM, additional identical “ride along” ACM’s were installed back to back, one front facing and one rear facing. The vehicle was also instrumented with a video VBOX to record speed at impact, and with the high precision “IST” accelerometer reference instrumentation. ACM’s facing toward the crash under-reported the negative longitudinal Delta V. After the initial impact was over, these forward facing ACM’s had a positive slope and at the end of the 200 ms recording were reporting a positive net Delta V, indicating a G sensor bias. The ACM’s facing away from the crash over reported the positive longitudinal Delta V. After the initial impact was over, these rear facing ACM’s continued to accumulate positive Delta V indicating a G sensor bias. By averaging the data between front and rear facing ACM’s, the crash induced portion of the data offset one another, leaving an average accelerometer bias of 0.87G.