Experimental investigation of light commercial vehicle traction-speed properties

Abstract

The article focuses on the experimental determination of the traction-speed properties of a light commercial vehicle in a passenger variant with a modified transmission for the further confirmation of the adequacy of the developed mathematical model of motion.

The features of the production and operation of modern light commercial vehicles are analyzed. It is established that the high degree of unification and the widespread practice of converting cargo variants into passenger ones results in a discrepancy between the parameters of powertrains and transmissions and the actual operating conditions. It is determined that one of the ways to eliminate such a mismatch is to modify the transmission gear ratios. Since such a modification affects the performance properties of the vehicle, there is a need to study its traction-speed properties through road tests.

The methodology of conducting experimental research using a measuring complex of high-frequency satellite telemetry with a sampling frequency of 10 Hz is proposed and applied. The experimental study involved a Volkswagen Caddy vehicle in a passenger variant, equipped with a dual-clutch transmission (DCT) with modified gear ratios of the higher gears. The test runs were performed for two mass variants: curb weight (including the driver and measuring equipment) and gross vehicle weight.

Based on the results of a series of test runs, the traction-speed properties were established. It is proven that an increase in the vehicle mass to the gross vehicle weight leads to a deterioration in the traction-speed properties: specifically, the acceleration time to a speed of 100 km/h increases by 34.3%, and the acceleration distance by 35.7%. An analysis of the smoothed curves of longitudinal acceleration confirmed that acceleration occurs with virtually no power interruption due to the high operating speed of the dual-clutch transmission.