Optimum Design of 1st Gear Ratio for 4WD Vehicles Based on Vehicle Dynamic Behaviour

Abstract EN

This paper presents an approach that allows optimizing gear ratio and vehicle dimension to achieve optimum gear transmission.

Therefore, augmented Lagrangian multiplier method, defined as classical method, is utilized to find the optimum gear ratios and the corresponding number of gear teeth applied to all epicyclical gears.

The new method is able to calculate and also to optimize the gear ratio based on dynamics of 4WD vehicles.

Therefore, 4WD vehicles dynamic equations are employed assuming that the rear wheels or the front wheels are at the point of slip.

In addition, a genetic algorithm is modified to preserve feasibility of the encountered solutions.

The basic dimension of a sample commercial vehicle (2009 hummer H3 4dr AWD SUV) and its gearbox are optimized, and then the effects of changing slip angle, wheel base, and engine torque on optimum vehicle dimension are analyzed.