Comparison of ABS Configurations and Their Effects on Stopping Performance and Stability for a Class 8 Straight-Truck 2005-01-3610
Direct vehicle performance comparisons were made between a full 6s/6m and a simpler 4s/4m system, as applied to a 6x4 Class 8 straight truck having a walking-beam rear suspension design. The 4s/4m system was run in both intermediate-axle control and trailing axle-control configurations. The systems were compared with modern air-disc brakes on the vehicle
The systems were compared at LLVW (unladen) and GVWR (fully loaded) for high speed stopping performance and stability on a high-μ surface and a wetted split-μ surface, as well as Brake-in-Curve stability on a wetted low-μ 500-ft radius turn.
In this paper, stopping distances are statistically compared to quantify effects of the various ABS control strategies on dry and wet stopping efficiency. In addition, newer techniques of using wheel-slip histograms generated from in-stop data are used to compare more detailed system behavior and predict their effects on vehicle stability under braking.
Although differences were seen in vehicle stopping performance and stability, they were minor where they existed. Wheel slip histograms for dry and wet stopping tests, as well as Brake-in-Curve stability results, did suggest that a very slight degradation in vehicle stability while stopping might exist in certain instances when using the simpler 4s/4m ABS control strategies, but certainly not to the extent to cause concern. Vehicle stability while braking was certainly not a concern for the test driver or engineers when using the simpler 4s/4m system.