Steering System with Mechanical Coupling of the Wheels and the Possibility of Wheel Steering in Opposite Directions

Abstract

In the course of the U-Shift project, an automated, driverless and electrically driven vehicle concept is developed. By separating the vehicle into a drive module and a transport capsule, a novel form of mobility is created. The autonomous driving module, the so-called Driveboard, is able to change the transport capsules independently and thus serves both passenger and goods transport. In order to be able to use the vehicle effectively, especially in urban areas, the space required for manoeuvring and loading or unloading the capsules must be kept as small as possible. This poses special challenges for the steering system.In this paper, a novel steering system is presented that enables both same-direction and opposite-direction wheel steering. First, the fundamental concept of the steering system is presented. After that, the design is explained and the assembled steering system is shown. During normal cornering, there is a mechanical coupling between the wheels. Which means that the occurring forces and moments are mutually supported by the wheels. This minimises the energy demand of the steering system. To manoeuvre the vehicle with minimal space requirements the mechanical coupling of the wheels can be disconnected. By turning the front wheels in the opposite direction to the centre of the vehicle, the pivot point of the vehicle can be shifted to the centre of the rear axle. The vehicle can thus be turned around the centre of the rear axle, which reduces the space required for manoeuvring to a necessary minimum. The steering system presented thus allows the advantages of a conventional steering system to be combined with the advantages of single-wheel steering system.