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Battery-electric vehicles (BEVs) require new chassis components, which are realized as mechatronic systems mainly and support more and more by-wire functionality. Besides better controllability, it eases the implementation of integrated control strategies to combine different domains of vehicle dynamics. Especially powertrain layouts based on electric in-wheel machines (IWMs) require such an integrated approach to unfold their full potential. The present study describes an integrated, longitudinal vehicle dynamics control strategy for a battery electric sport utility vehicle (SUV) with an electric rear axle based on in-wheel propulsion. Especially the influence of electronic brake force distribution (EBD) and torque blending control on the overall performance are discussed and demonstrated through experiments and driving cycles on public road and benchmarked to results of previous studies derived from [1].

In recent years, driving simulators have become a valuable tool in the automotive design and testing process. Yet, in the field of vehicle dynamics, most decisions are still based on test drives in real cars. One reason for this situation can be found in the fact that many driving simulators do not allow the driver to evaluate the handling qualities of a simulated vehicle. In a driving simulator, the motion cueing algorithm tries to represent the vehicle motion within the constrained motion envelope of the motion platform. By nature, this process leads to so called false cues where the motion of the platform is not in phase or moving in a different direction with respect to the vehicle motion. In a driving simulator with classical filter-based motion cueing, false cues make it considerably more difficult for the driver to rate vehicle dynamics.

At single irregularities, such as manhole covers and joints in concrete road surfaces, axle and engine vibrations are increased. Depending on the response characteristic of the vehicle chassis and seats and the duration of the event, such excitations can have a considerable influence on the comfort of vehicle occupants. With the objective of optimising the vibration characteristics of the axles of a vehicle, a procedure is presented which clarifies the motion sequences due to certain types of excitation on a roller test stand. This knowledge permits the optimisation of the axle kinematics, the axle bearings, and the spring-damper system.

The aim of this investigation is the improvement of the lateral vehicle dynamics by optimizing the rim width. For that purpose, the rim width is considered as a development tool and configured with regard to specified targets. Using a specifically developed method of simulation, the influence of the rim width is analysed within different levels - starting at the component level “tyre” and going up to the level of the whole vehicle. With the help of substantial simulations using a nonlinear two-track model, the dimensioning of the rim width is brought to an optimum. Based on both, tyre and vehicle measurements, the theoretical studies can be proved in practice. As a result, the rim width has a strong influence on the behaviour of the tyre as well as on the overall vehicle performance, which emphasises its importance as a potential development tool within the development of a chassis.

The aerodynamic development of the new Audi Q5 (released in 2017) is described. In the course of the optimization process a number of different tools has been applied depending on the chronological progress in the project. During the early design phase, wind tunnel experiments at 1:4 scale were performed accompanied by transient DES and stationary adjoint simulations. At this stage the model contained a detailed underbody but no detailed engine bay for underhood flow. Later, a full scale Q5 model was built up for the aerodynamic optimization in the 1:1 wind tunnel at Audi AG. The model featured a detailed underbody and engine bay including original parts for radiators, engine, axles and brakes from similar vehicles. Also the 1:1 experiments were accompanied by transient DES and stationary adjoint simulations in order to predict optimization potential and to better understand the governing flow.

In order to optimize the function of an automobile seat, its geometrical and physical properties must be designed so that the loads resulting from the body weight and ambient factors (such as vibration, forces arising from vehicle dynamics, climatic conditions) act on the body of the occupant in such a way that the stress to which it is subjected is kept to a minimum. The physically measurable loads subject the driver to stress, i.e. they act mainly by changing biological processes in the organism, and drivers of widely different body statures must be considered. So the “correct” seat will necessarily be a compromise. From a careful integration of all requirements using the latest techniques, it emerged that an all-foam seat cushion incorporating varying degrees of firmness could be used to advantage. In this way Audi succeeded relatively quickly in designing a seat arrangement with remarkably positive characteristics.