Vehicle dynamics

About: Vehicle dynamics is a research topic. Over the lifetime, 12909 publications have been published within this topic receiving 204091 citations.

Stabilizing traffic flow via a single autonomous vehicle: Possibilities and limitations

Abstract: In certain flow regimes, the ideal uniform vehicle flow on the road is unstable, and stop-and-go traffic develops. The instability that leads to this less fuel-efficient unsteady flow results from the collective behavior of all human drivers. This work studies under which circumstances the presence of a single autonomous vehicle (AV) can locally stabilize the flow, without changing the way the humans drive. If possible, this can enable traffic flow control via very few AVs serving as mobile actuators. First, the analysis of car-following models reveals that in idealized conditions (no system noise), the flow can in fact be made linearly stable by means of a low fraction of control vehicles. Second, we highlight the fundamental limitations of this sparse control when considering models with noise.

Vehicle dynamics control of four in-wheel motor drive electric vehicle using gain scheduling based on tyre cornering stiffness estimation

Abstract: This paper focuses on the vehicle dynamic control system for a four in-wheel motor drive electric vehicle, aiming at improving vehicle stability under critical driving conditions. The vehicle dynamics controller is composed of three modules, i.e. motion following control, control allocation and vehicle state estimation. Considering the strong nonlinearity of the tyres under critical driving conditions, the yaw motion of the vehicle is regulated by gain scheduling control based on the linear quadratic regulator theory. The feed-forward and feedback gains of the controller are updated in real-time by online estimation of the tyre cornering stiffness, so as to ensure the control robustness against environmental disturbances as well as parameter uncertainty. The control allocation module allocates the calculated generalised force requirements to each in-wheel motor based on quadratic programming theory while taking the tyre longitudinal/lateral force coupling characteristic into consideration. Simulations under a variety of driving conditions are carried out to verify the control algorithm. Simulation results indicate that the proposed vehicle stability controller can effectively stabilise the vehicle motion under critical driving conditions.

Attention Based Vehicle Trajectory Prediction

Abstract: Self-driving vehicles need to continuously analyse the driving scene, understand the behavior of other road users and predict their future trajectories in order to plan a safe motion and reduce their reaction time. Motivated by this idea, this paper addresses the problem of vehicle trajectory prediction over an extended horizon. On highways, human drivers continuously adapt their speed and paths according to the behavior of their neighboring vehicles. Therefore, vehicles’ trajectories are very correlated and considering vehicle interactions makes motion prediction possible even before the start of a clear maneuver pattern. To this end, we introduce and analyze trajectory prediction methods based on how they model the vehicles interactions. Inspired by human reasoning, we use an attention mechanism that explicitly highlights the importance of neighboring vehicles with respect to their future states. We go beyond pairwise vehicle interactions and model higher order interactions. Moreover, the existence of different goals and driving behaviors induces multiple potential futures. We exploit a combination of global and partial attention paid to surrounding vehicles to generate different possible trajectory. Experiments on highway datasets show that the proposed model outperforms the state-of-the-art performances.

Integrated Vehicle Dynamics Control —state-of-the art review

Abstract: Chassis control systems have evolved dramatically over the past two decades and their impacts on vehicle dynamics can be usefully separated into the three directions, i.e. lateral, longitudinal and vertical directions. Accordingly, the state survey of chassis control systems can be reviewed in following sub-system areas, i.e. steering, driveline/braking and suspension. The developments within each of these areas have progressed at different rates and each has had different impacts on improving vehicle behavior in relation to safety, ride, handling dynamics or economy. However, the biggest challenge is in the whole chassis integration of these sub-systems to avoid their interventions and thus to improve overall vehicle dynamics performance. Hence, a hot research topic, named integrated vehicle dynamics control (IVDC) or integrated chassis control, arose. Based on the published literatures in the recent twenty years, this paper presents a comprehensive state of the art survey on IVDC. First, the roadmap and methodologies of IVDC are reviewed, and then the control strategies of coordination between the subsystems are summarized. At present, integration technique between steering and braking/traction has been most concerned, and is being researched and developed intensively both in academic and industrial aspects. It can be expected that once X-by-Wire technology and actuator hardware are further developed, more potential benefits of IVDC can be obtained.