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Vehicle dynamics

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


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Proceedings ArticleDOI
10 Jun 2009
TL;DR: An elaborate comparative analysis of the proposed Adaptive Robust Controller for Hypersonic Vehicles (ARCH) is carried out using a control verification methodology, which enables the quantification of the improvements that result from using and adaptive controller for a typical maneuver in the V - h space under cruise conditions.
Abstract: This paper proposes an adaptive controller for a hypersonic cruise vehicle subject to aerodynamic uncertainties, center-of-gravity movements, actuator saturation, failures, and time-delays. The adaptive control architecture is based on a linearized model of the underlying rigid body dynamics and explicitly accommodates for all uncertainties. It also includes a baseline proportional integral filter commonly used in optimal control designs. The control design is validated using a high-fidelity HSV model that incorporates various effects including coupling between structural modes and aerodynamics, and thrust pitch coupling. An elaborate comparative analysis of the proposed Adaptive Robust Controller for Hypersonic Vehicles (ARCH) is carried out using a control verification methodology. In particular, we study the resilience of the controller to the uncertainties mentioned above for a set of closed-loop requirements that prevent excessive structural loading, poor tracking performance and engine stalls. This analysis enables the quantification of the improvements that result from using and adaptive controller for a typical maneuver in the V - h space under cruise conditions.

96 citations

Journal ArticleDOI
TL;DR: In this paper, an adaptive tire force model that takes variations in road friction into account is proposed to calculate lateral tire forces, vehicle sideslip angle, and road friction. But the adaptive observer is evaluated in comparison with two nonadaptive observers that use tire force models with fixed parameters.
Abstract: The estimation of vehicle dynamic variables is essential for the enhancement of safety, in particular for braking and trajectory-control systems. This paper proposes a new estimation process to calculate lateral tire forces, vehicle sideslip angle, and road friction. The estimation process (an adaptive observer) is constructed by combining a vehicle model and a tire force model. More specifically, this study proposes an adaptive tire force model that takes variations in road friction into account. The adaptive observer is evaluated in comparison with two nonadaptive observers that use tire force models with fixed parameters. This study also proposes a road friction identification method operating in an online context. The observers and the road friction identification method are first evaluated using vehicle simulator software. Subsequently, observers are compared to real data acquired using an experimental vehicle. This paper also includes a description of the experimental platform. Results show the accuracy and potential of the estimation process.

95 citations

Journal ArticleDOI
TL;DR: The stability and error convergence of the integrated control system in the presence of the uncertain parameters, which is a very essential feature for the active safety means, is guaranteed by utilizing a Lyapunov function.
Abstract: This paper presents an adaptive nonlinear control scheme aimed at the improvement of the handling properties of vehicles. The control inputs for steering intervention are the steering angle and wheel torque for each wheel, i.e., two control inputs for each wheel. The control laws are obtained from a nonlinear 7-degree-of-freedom (DOF) vehicle model. A main loop and eight cascade loops are the basic components of the integrated control system. In the main loop, tire friction forces are manipulated with the aim of canceling the nonlinearities in a way that the error dynamics of the feedback linearized system has sufficient degrees of exponential stability; meanwhile, the saturation limits of tires and the bandwidth of the actuators in the inner loops are taken into account. A modified inverse tire model is constructed to transform the desired tire friction forces to the desired wheel slip and sideslip angle. In the next step, these desired values, which are considered as setpoints, are tackled through the use of the inner loops with guaranteed tracking performance. The vehicle mass and mass moment of inertia, as unknown parameters, are estimated through parameter adaptation laws. The stability and error convergence of the integrated control system in the presence of the uncertain parameters, which is a very essential feature for the active safety means, is guaranteed by utilizing a Lyapunov function. Computer simulations, using a nonlinear 14-DOF vehicle model, are provided to demonstrate the desired tracking performance of the proposed control approach.

95 citations

Journal ArticleDOI
TL;DR: In this paper, a real-time estimation of the wheel slip value corresponding to the peak of the tire-road friction curve is proposed to provide anti-lock braking systems with reliable information on its value upon activation.
Abstract: Tire-road friction characteristics are deeply interlaced with all vehicle dynamics control systems, as road conditions strongly affect the control schemes behaviour. This work aims at the real-time estimation of the wheel slip value corresponding to the peak of the tire-road friction curve, in order to provide anti-lock braking systems (ABS) with reliable information on its value upon activation. Different techniques based on recursive least squares and the maximum likelihood approach are used for friction curve fitting and their merits and drawbacks thoroughly examined. In addition, since one of the main issues in slip-based friction estimation during braking is vehicle speed estimation, an effective algorithm for addressing this task is developed. The proposed peak slip value estimation strategy is analysed and tested both in simulation and on data collected on an instrumented test vehicle. In the latter case, the vehicle speed estimation algorithm is used, and the estimated vehicle speed provided as input for friction estimation. Practical applicability constraints posed by typical ABS systems are also considered.

95 citations

Journal ArticleDOI
TL;DR: The use of two-degrees-of-freedom control architecture known as the model regulator is investigated here as a robust steering controller for such yaw stabilization tasks in a driver-assist system to improve vehicle-handling quality.
Abstract: Unsymmetrical loading on a car like mu-split braking, side wind forces, or unilateral loss of tire pressure results in unexpected yaw disturbances that require yaw stabilization either by the driver or by an automatic driver-assist system. The use of two-degrees-of-freedom control architecture known as the model regulator is investigated here as a robust steering controller for such yaw stabilization tasks in a driver-assist system. The yaw stability-enhancing steering controller is designed in the parameter space to satisfy a frequency-domain mixed sensitivity constraint. To evaluate the resulting controller design, a real-time hardware-in-the-loop simulator is developed. Steering tests with and without the controller in this hardware-in-the-loop setup allow the driver to see the effect of the proposed controller to improve vehicle-handling quality. The hardware-in-the-loop simulation setup can also be used for real-time driver-in-the-loop simulation of other vehicle control systems.

95 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023167
2022478
2021620
2020811
2019749
2018749