Novel Chassis Concept for Omnidirectional Driving Maneuvers - Challenges in modelling suspensions with wheel individual steering system

Automobiles increase the mobility of their users. However, their maneuverability is pushed to the limit by cramped inner city conditions. Those who need to park their vehicles frequently, such as delivery services and mobile care providers, waste a lot of working time searching for and then getting into parking spaces. New chassis types with wheels that can be steered individually and electric drives make it possible to increase maneuverability and therefore efficiency, particularly in flowing urban traffic.



The joint research project “OmniSteer” subsidized by the Federal Ministry for Education and Research (BMBF) focuses on such novel chassis concepts with electric drives and individually steerable wheel. The highest demands are placed on the chassis, which should allow a steering angle of 90° in each direction on each wheel.

As part of the OmniSteer project, a scaled-down demonstration vehicle with a lateral and transverse guidance system capable of performing orthogonal, multi-directional, and non-linear driving and steering maneuvers is being developed. These three features allow innovative driving functions and thus make it possible to utilize the full potential of automation in electrically-driven vehicles. ... mehrThe vehicle will use sensors to identify its surroundings, calculate the best possible path of travel, and then independently perform complex maneuvers.

In order to gain the knowledge about the vehicle dynamic behavior in omnidirectional driving maneuvers as well as the forces and moments within the suspension and steering system to support the mechanical design, a corresponding vehicle dynamics model must be provided. The focus of modeling is the novel suspension and steering system. However, the novel concept is not depicted in present simulation tools.

To solve this problem, a multibody model (MB-Model) for the suspension and steering system has been built using Matlab Simscape Toolbox. The kinematics of the suspension system can be obtained from the MB-Model and be saved as a skc-file, which provides the information about the characteristics of the suspension system in IPG-CarMaker. With the new User Accessible Quantities in IPG-CarMaker, the MB-Model can be directly applied in CarMaker for Simulink environment as steering system.