Vehicle dynamics

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

Vehicle Yaw Stability-Control System Design Based on Sliding Mode and Backstepping Control Approach

Abstract: A yaw stability-control system is designed to make vehicle yaw rate follow its reference in this paper. Based on the sliding-mode and backstepping approach, the cascade control system is combined with a tire/road force observer and a yaw stability controller. The tire/road force observer considers wheel longitudinal force as an unknown input to wheel dynamics and uses the sliding-mode method to reconstruct it. The yaw stability controller is designed based on a model about vehicle yaw rate, and the wheel dynamics were chosen according to the vehicle situation. In backstepping framework, brake torque is calculated in two steps. The performance is evaluated in a critical cornering maneuver situation through simulation with a multibody vehicle dynamics software, and the result indicates that the proposed controller can significantly maintain vehicle stability for active safety.

Fusion Algorithm Design Based on Adaptive SCKF and Integral Correction for Side-Slip Angle Observation

Abstract: Vehicle side-slip angle is crucial for various vehicle active safety applications, but measuring it directly needs expensive measurement instruments and the vehicle nonlinear dynamics, parameters uncertainty, and sensor noise cause difficulties in its observation. Therefore, the accurate, affordable side-slip angle estimator is essential. Thus, a novel adaptive square-root cubature Kalman filter (ASCKF)-based estimator with the integral correction fusion is proposed. First, the square-root cubature Kalman filter (SCKF) parameters can be adjusted adaptively based on the vehicle dynamics states. Then, considering the unknown colored noises of sensors, the integral estimation is corrected by the damping item and zero-point-reset method and the integral value can compensate the estimation error caused by the vehicle nonlinear dynamics. Therefore, the accurate side-slip angle can be estimated by the adaptive fusion of the estimation and integral values. The simulation results and real-vehicle tests show that the proposed ASCKF-based fusion algorithm has better performance than both the traditional SCKF and ASCKF.

Observer Kalman filter identification of an autonomous underwater vehicle

Abstract: This paper deals with the identification of linear discrete-time multivariable models of an autonomous underwater vehicle (AUV). The observer Kalman filter identification (OKID) method is applied with the main objective of evaluating its effectiveness to the experimental identification of the dynamic behaviour of an AUV. After presenting the mathematical background of the OKID algorithm, the proposed method is first validated on the basis of simulated data of both the linearized and nonlinear yaw dynamics of an AUV. Subsequently, the identification algorithm is applied to a set of experimental data. Results suggest that the method can be an efficient tool for the experimental identification of AUV dynamics.

Stabilization of a flying vehicle on a taut tether using inertial sensing

Abstract: Given a hover-capable flying vehicle attached to a fixed point by a taut tether, we present a novel method to recover the vehicle's relative position and absolute orientation. The proposed method requires only on-board inertial sensors, and indirectly measures the string force, enabling the additional use of the tether as a physical user interaction medium. We present the vertical-plane dynamics of such a system and the localization approach, discuss sensitivity issues, and implement an estimator and controller based on the presented model. We demonstrate the method experimentally on a tethered quadrocopter in the Flying Machine Arena, using both a vertical-plane-constrained vehicle and in 3D.

Improved bushing models for general multibody systems and vehicle dynamics

Abstract: The development and computational implementation, on a multibody dynamics environment, of a constitutive relation to model bushing elements associated with mechanical joints used in the models of road and rail vehicles is presented here These elements are used to eliminate vibrations in vehicles, due to road irregularities, to allow small misalignment of axes, to reduce noise from the transmission, or to decrease wear of the mechanical joints Bushings are made of a special rubber, used generally in energy dissipation, which presents a nonlinear viscoelastic relationship between the forces and moments and their corresponding displacements and rotations In the methodology proposed here a finite element model of the bushing is developed in the framework of the finite element code ABAQUS to obtain the constitutive relations of displacement/rotation versus force/moment for different loading cases The bushing is modeled in a multibody code as a nonlinear restrain that relates the relative displacements between the bodies connected with the joint reaction forces, and it is represented by a matrix constitutive relation The basic ingredients of the multibody model are the same vectors and points relations used to define kinematic constraints in any multibody formulation One particular, and relevant, characteristic of the formulation now presented is its ability to represent standard kinematic joints, clearance, and bushing joints just by defining appropriate constitutive relations Spherical, revolution, cylindrical, and translational bushing joints are modeled, implemented, and demonstrated through the simulation of two multibody models of a road vehicle, one with perfect kinematic joints for the suspension sub-systems, and other with bushing joints The tests conducted include an obstacle avoidance maneuver and a vehicle riding over bumps It is shown that the bushing models for vehicle multibody models proposed here are accurate and computationally efficient so that they can be included in the vehicle models leading reliable simulations