This paper formulates force constraints of over-actuated road vehicles. In particular, focus is put on different vehicle configurations provided with electrical drivelines. It is demonstrated that a number of vehicles possesses non-convex tyre and actuator constraints, which have an impact on the way in which the actuators are to be used. By mapping the actuator forces to a space on a global level, the potential of the vehicle motion is investigated for the vehicles studied. It is concluded that vehicles with individual drive, compared with individual brakes only, have a great potential to yaw motion even under strong lateral acceleration.

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Fault-tolerant vehicle design is an emerging inter-disciplinary research domain, which is of increased importance due to the electrification of automotive systems. The goal of fault-tolerant systems is to handle occuring faults under operational condition and enable the driver to get to a safe stop. This paper presents results from an extended survey on fault-tolerant vehicle design. It aims to provide a holistic view on the fault-tolerant aspects of a vehicular system. An overview of fault-tolerant systems in general and their design premises is given as well as the specific aspects related to automotive applications. The paper highlights recent and prospective development of vehicle motion control with integrated chassis control and passive and active fault-tolerant control. Also, fault detection and diagnosis methods are briefly described. The shift on control level of vehicles will be accompanied by basic structural changes within the network architecture. Control architecture as well as communication protocols and topologies are adapted to comply with the electrified automotive systems. Finally, the role of regulations and international standardization to enable fault-tolerant vehicle design is taken into consideration.

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The capability of over-actuated vehicles to maintain stability during limit handling is studied in this paper. A number of important differently actuated vehicles, equipped with hydraulic brakes toward more advanced chassis solutions, are presented. A virtual evaluation environment has specifically been developed to cover the complex interaction between the driver and the vehicle under control. In order to fully exploit the different actuators setup, and the hard nonconvex constraints they possess, the principle of control allocation by nonlinear optimization is successfully employed. The final evaluation is made by exposing the driver and the over-actuated vehicles to a safety-critical double lane change. Thereby, the differently actuated vehicles are ranked by a quantitative indicator of stability.

The growing concerns about the environmental issues caused by vehicles and a strive for better fuel economy, urge the legislators to introduce conservative regulations on vehicle testing and homologation procedures. To have accurate evaluations, driving cycles that can sufficiently describe the vehicles' conditions experienced during driving is a prerequisite. In current driving cycles there are still some issues which are disregarded. The aim of the presented work is to study the contribution of chassis and vehicle dynamics settings on tyre rolling loss in comparison with the original assumptions made in the NEDC, FTP and HWFET driving cycles. A half-car model including a semi-physical explicit tyre model to simulate the rolling loss is proposed. For the chosen vehicle and tyre characteristics, depending on the specific chassis settings and considered driving cycle, considerable difference up to 7% was observed between the energy consumption of the proposed-and conventional approach. The current work aims to provide the legislators with a better insight into the real effects of chassis and vehicle dynamics during the certification process to further improve the test related procedures required for homologation such as generation of road load curves. I.e., the aim is not to provide a new homologation process, since there are also other effects such as road roughness and tyre temperature that need to be considered. The results are also of interest for the vehicle manufacturers for further considerations during test preparation as well as in the development phase in order to reduce the environmental impacts.

An active energy-efficient direct yaw moment control (DYC) for in-wheel motor electric vehicles taking motor efficiency maps into consideration is proposed in this paper. The potential contribution of DYC to energy saving during quasi-steady-state cornering is analysed. The study in this paper has produced promising results which show that DYC can be used to reduce the power consumption while satisfying the same cornering demand. A controller structure that includes a driver model and an offline torque distribution law during continuous driving and cornering is developed. For comparison, the power consumption of stability DYC is also analysed. Simulations for double lane change manoeuvres are performed and driving conditions either with a constant velocity or with longitudinal acceleration are designed to verify the effectiveness of the proposed controller in different driving situations. Under constant velocity cornering, since the total torque demand is not high, two rear wheels are engaged and during cornering it is beneficial to distribute more torque to one wheel to improve energy efficiency. In the simulated driving manoeuvres, up to 10% energy can be saved compared to other control methods. During acceleration in cornering, since the total torque demand is high, it is energy-efficient to use all the four in-wheel motors during cornering.