The Accuracy of Toyota Vehicle Control History Data during Autonomous Emergency Braking 2018-01-1441
Newer Toyota vehicles store information about more than 50 parameters for 5 s before and after non-collision events in the Vehicle Control History (VCH) records. The goals of this study were to assess the accuracy of VCH data acquired during Autonomous Emergency Braking (AEB) events and to investigate the effects of speed, acceleration, and system settings on AEB performance. A 2017 Toyota Corolla with Safety Sense P Pre-Collision System (PCS) was driven in a straight line towards a car-like target at different combinations of four speeds (20, 25, 30, and 40 km/h; or
12, 15, 19, and 25 mph) and three accelerator pedal positions (constant 30%, 40%, and 50% accelerator opening ratios) until the AEB system activated. The vehicle speed, vehicle acceleration, radar target closing speed, and radar target distance recorded in the VCH were compared to a reference 5th wheel. We found that errors in the VCH distance, speed, and acceleration data varied with the test conditions. Regression equations were derived to better predict distance, speed, and acceleration from the VCH data. A driver-adjustable PCS warning setting only altered the timing of the warning and not the underlying AEB response. The vehicle struck the target most often at 20 km/h (12 mph) when accelerating towards the target, but did not strike the target when approaching it at a constant speed of 20 km/h. This study serves as an initial investigation into the accuracy of VCH data and the performance of the Toyota PCS under various conditions and settings.