Search Results

An instrumented 2005 Ford Explorer was used to evaluate speed data provided from its Powertrain Control Module (PCM) at high slip angles. PCM speed was compared to speed and slip angle collected from a calibrated Datron S-400 velocity sensor. In addition to speed, slip angle and other standard handling test measurements the vehicle brake switch and throttle were recorded so PCM data could be synchronized. After each test run the vehicle ignition was turned off and the PCM was downloaded using commercially available Bosch hardware and software. The principal maneuver was the National Highway Traffic Safety Administration (NHTSA) sine-with-dwell test consisting of a 0.7 HZ sinusoidal steer with a 0.5 second dwell at the steer reversal peak. Runs were conducted with the vehicle’s Electronic Stability Control (ESC) disengaged so that the test vehicle would achieve large slip angles.

A series of rollover tests was conducted in a real-world environment in which a vehicle was driven or towed to highway speed then steered to induce a rollover. This research presents analysis of the rollover phase of five tests. In each test, the steering maneuver was initiated on-pavement, and the rollover was caused by tire-to-ground interaction. Tests included vehicles that tripped both on-pavement and on soil. Four tests ended with the vehicle at rest off-road, and one ended with the vehicle remaining on the pavement. A programmable remote control radio was used to steer the vehicles through a double-step steer maneuver to result in a rollover. The test vehicles were instrumented and data was collected during each test, including steering, suspension motion, rotational rates, and accelerations. A Global Positioning System (GPS) speed sensor (VBOX III manufactured by Racelogic) was used to monitor the vehicle speed. Data from all tests is presented in the Appendix .