Vehicle dynamics

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

Optimal control allocation in vehicle dynamics control for rollover mitigation

Abstract: Vehicle dynamics control systems, previously only intended for yaw stabilization, are now being extended to incorporate rollover mitigation via braking. Current systems typically use a heuristic approach to control allocation, often utilizing only a subset of the available actuators. In this article a computationally-efficient, optimization-based control allocation strategy is used to map controller commands to braking forces on all four wheels, taking into account actuator constraints. Simulations show that the strategy is capable of preventing vehicle rollover for various standard test manoeuvres.

Deception Attack Detection and Estimation for a Local Vehicle in Vehicle Platooning Based on a Modified UFIR Estimator

Abstract: In this article, the position sensor deception attack detection and estimation problem is investigated for a local vehicle in a vehicle platoon. In a platoon system, the position measurement is critical as the distances between neighboring vehicles are relatively small. However, the position measurement of vehicles is usually vulnerable to deception attacks as it relies on external information, such as GPS and environment information from cameras. Therefore, position sensor deception attack detection and estimation should be addressed for local vehicles in a platoon. To deal with this problem, a linearized model is presented to describe the longitudinal dynamics of a local vehicle. Moreover, modeling uncertainties, measurement noises, and piecewise constant deception attacks injected in position measurement are specified along with this model. Based on this model, a scheme based on a modified unbiased finite impulse response (UFIR) estimator is proposed to generate an intermediate estimated value related only to the attack. Then, the deception attack is recovered based on this value through a function fitting strategy. Based on analysis results, simulations are conducted to verify the effectiveness of the proposed attack detection and estimation scheme.

Simultaneous Estimation of Road Profile and Tire Road Friction for Automotive Vehicle

Abstract: The longitudinal motion control of automotive vehicles is heavily reliant on information about the time-varying tire road friction coefficient. In the presence of varying road roughness profiles, the effective vertical load on each wheel varies dynamically, influencing the tire friction. In this paper, we integrated the vertical and longitudinal dynamics of a quarter wheel to form an integrated nonlinear model. In the modeled dynamics, the time-varying random road profile and the tire friction are treated as unknown inputs. To estimate these unknown inputs and states simultaneously, a combination of nonlinear Lipschitz observer and modified super-twisting algorithm (STA) observer is developed. Under Lipschitz conditions for the nonlinear functions, the convergence of the estimation error is established. Simulation results performed with the high-fidelity vehicle simulation software CarSim demonstrate the effectiveness of the proposed scheme in the estimation of states and unknown inputs.

Immersion and Invariance-Based Output Feedback Control of Air-Breathing Hypersonic Vehicles

Abstract: A new output feedback control design for robust velocity and altitude tracking of an air-breathing hypersonic vehicle (AHSV) is presented in this paper. The control scheme is performed on the assumption that only partial states of AHSV are measurable. The key idea is to employ the immersion and invariance approach to design globally asymptotically stable observers for the unmeasurable states. For controller design, the whole control architecture is constructed using dynamic surface control, based on the decomposition of the longitudinal dynamics of AHSV into velocity and altitude subsystems. Stability analysis is presented using the Lyapunov theory. Representative simulations are carried out on the high-fidelity model, which illustrate the effectiveness and robustness of the proposed scheme.

Fuzzy Static Output Feedback Control for Path Following of Autonomous Vehicles With Transient Performance Improvements

Abstract: This paper provides a new solution for path following control of autonomous ground vehicles. $\mathcal {H}_{2}$ control problem is considered to attenuate the effect of the road curvature disturbance. To this end, we formulate a standard model from the road-vehicle dynamics, the a priori knowledge on the road curvature, and the path following specifications. This standard model is then represented in a Takagi–Sugeno fuzzy form to deal with the time-varying nature of the vehicle speed. Based on a static output feedback scheme, the proposed method allows avoiding expensive vehicle sensors while keeping the simplest control structure for real-time implementation. The concept of $\mathcal {D}-$ stability is exploited using Lyapunov stability arguments to improve the transient behaviors of the closed-loop vehicle system. In particular, the physical upper and lower bounds of the vehicle acceleration are explicitly considered in the design procedure via a parameter-dependent Lyapunov function to reduce drastically the design conservatism. The proposed $\mathcal {H}_{2}$ design conditions are expressed in terms of linear matrix inequalities (LMIs) with a single line search parameter. The effectiveness of the new path following control method is clearly demonstrated with both theoretical illustrations and hardware experiments under real-world driving situations.