Vehicle dynamics

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

Improved vehicle performance using combined suspension and braking forces

Abstract: SUMMARY This work presents a preliminary investigation into the integration of particular subsystems of an automobile's chassis. The specific focus of this research is the integration of Active Suspension components with Anti-Lock braking (ABS) mechanisms. The performance objective for the integrated approach is defined as a reduction in braking distance over just anti-lock brakes. Several models, of varying degrees of complexity, are presented to determine the effect of modeling accuracy on the potential performance improvement. In the most detailed model, a four degree of freedom Half Car vehicle model is developed along with models for a hydraulic Active Suspension and an ABS system. For both subsystems, actuator dynamics are included. The tire-road interface is modeled using the Magic Formula tire model. Individual controllers are developed for the subsystems and a governing algorithm is constructed to coordinate the two controllers. Simulations of the integrated controller and an ABS system, for each...

Adaptive Sliding Mode Fault-Tolerant Coordination Control for Four-Wheel Independently Driven Electric Vehicles

Abstract: Four wheel independently driven (4WID) electric vehicles are promising vehicle architectures. However, the complex coordination control of the four driving motors and the operation reliability of the vehicle are challenges. In this paper, to address the multimotor coordinate operation against the actuator faults in the 4WID system, combining the adaptive sliding mode (ASM) control and the fault-tolerant (FT) control allocation, an adaptive sliding mode fault-tolerant coordination (ASM-FTC) control is proposed. First, a new vehicle dynamic model with a driving motor fault is set up. In the control layer, an adaptive variable exponential reaching law is used in the ASM to alleviate the chattering and improve the reaching speed, precision, and robustness. Then, the FTC allocation based on the quadratic programming is designed to properly coordinate the four in-wheel motors at the presentation of the motor fault. To verify the proposed control method, a 4WID electric vehicle platform is set up. Simulation and experimental results demonstrate the effectiveness of the ASM-FTC control.

Adaptive Observer-Based Parameter Estimation With Application to Road Gradient and Vehicle Mass Estimation

Abstract: A novel observer-based parameter estimation scheme with sliding mode term has been developed to estimate the road gradient and the vehicle weight using only the vehicle's velocity and the driving torque. The estimation algorithm exploits all known terms in the system dynamics and a low-pass filtered representation of the dynamics to derive an explicit expression of the parameter estimation error without measuring the acceleration. The proposed parameter estimation scheme which features a sliding-mode term to ensure the fast and robust convergence of the estimation in the presence of persistent excitation is augmented to an adaptive observer and analyzed using Lyapunov Theory. The analytical results show that the algorithm is stable and ensures finite-time error convergence to a bounded error even in the presence of disturbances. In the absence of disturbances, convergence to the true values in finite time is guaranteed. A simple practical method for validating persistent excitation is provided using the new theoretical approach to estimation. This is validated by the practical implementation of the algorithm on a small-scaled vehicle, emulating a car system. The slope gradient as well as the vehicle's mass/weight are estimated online. The algorithm shows a significant improvement over previous results.

A polynomial chaos approach to the analysis of vehicle dynamics under uncertainty

Abstract: The ability of ground vehicles to quickly and accurately analyse their dynamic response to a given input is critical to their safety and efficient autonomous operation. In field conditions, significant uncertainty is associated with terrain and/or vehicle parameter estimates, and this uncertainty must be considered in the analysis of vehicle motion dynamics. Here, polynomial chaos approaches that explicitly consider parametric uncertainty during modelling of vehicle dynamics are presented. They are shown to be computationally more efficient than the standard Monte Carlo scheme, and experimental results compared with the simulation results performed on ANVEL (a vehicle simulator) indicate that the method can be utilised for efficient and accurate prediction of vehicle motion in realistic scenarios.

Distributed Secure Platoon Control of Connected Vehicles Subject to DoS Attack: Theory and Application

Abstract: This article addresses the distributed secure platoon control of connected vehicles with denial-of-service (DoS) attack phenomena, which may occur at some sampling time instant. First, a switched time-delay system model is introduced, which captures the time-varying sampling and the DoS attack phenomena simultaneously. Then, sufficient conditions are obtained based on the Lyapunov stability theory, the Jensen’s Inequality method, and the topology matrix decoupling technique, such that the vehicle platoon system under consideration achieves an exponential tracking performance. In this article, the presented system design conditions establish several quantitative relationships between attack parameters and system performance. Moreover, the critical values of attack frequency (AF) and the sampling interval (SI) are also derived, respectively. Finally, both of the simulation and experiment studies on a network of four vehicles are introduced to validate the design.