Evaluation of the SIMON Tractor-Semitrailer Model for Steady State and Transient Handling 2006-01-3479
This research compares the responses of a vehicle modeled in the 3D vehicle simulation program SIMON in the HVE simulation operating system against instrumented responses of a 3-axle tractor, 2-axle semi-trailer combination. The instrumented tests were previously described in SAE 2001-01-0139 and SAE 2003-01-1324 as part of a continuous research effort in the area of vehicle dynamics undertaken at the Vehicle Research and Test Center (VRTC). The vehicle inertial and mechanical parameters were measured at the University of Michigan Transportation Research Institute (UMTRI). The tire data was provided by Smithers Scientific Services, Inc. and UMTRI.
The series of tests discussed herein compares the modeled and instrumented vehicle responses during quasi-steady state, steady state and transient handling maneuvers, producing lateral accelerations ranging nominally from 0.05 to 0.5 G's.
The time response of the following variables is compared graphically:
Tractor lateral acceleration
Tractor yaw rate
Trailer lateral acceleration
Simulated responses are found to track instrumented vehicle responses through the transient and steady state phases. Error percentages for peak or steady state values are reported, depending on the test.
Tractor lateral acceleration data was found to be inconsistent with the trailer lateral acceleration and tractor yaw rate in steady state maneuvers. The experimental tractor lateral acceleration values were scrutinized and found to be higher than predicted by approximately 9.6%-14.3%.
Steady state magnitudes for tractor yaw rate and trailer lateral acceleration between the simulated and experiment vehicles were observed to correlate well for maneuvers up to approximately 0.4 G's. The simulated responses fell below the experimental magnitudes in the above-0.5 G test. SIMON results were also compared to previously published results for the National Advanced Driving Simulator (NADS).