Basis for Logical Control of Circumferential Wheel Forces of Highway Trucks for Improved Traction and Fuel Effeciency

Distribution of traction forces among driving wheels is one of the main factors governing the performance of a highway truck during acceleration and braking on varying macro and micro road surface conditions. Comprehension of the interaction between wheels and road surface provides a profound systematic way to simulate a truck's motion and design required components for the optimal performance. The development of electronic technologies has created the pre-conditions necessary to develop systems with controlled parameters. However, to realize the pre-conditions, vehicle dynamics problems have to be formulated and solved for both optimization and control. Many different approaches emerged with the aid of electronics to control the circumferential wheel forces (wheel torque) by restricting wheel slip. A part of such systems has been named as Acceleration Slip Regulation (ASR) and Anti Slip Differentials (ASD). In this paper, we develop a methodology for maximum ASR and ASD to meet challenging road conditions. That is, a method for determining the optimal circumferential force distributions among driving wheels to provide maximum fuel efficiency and better tractive performance under different road conditions. This investigation is carried out for an articulated 6X4 tractor with two-axle semi trailer.