Vehicle dynamics

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

Investigation on dynamical interaction between a heavy vehicle and road pavement

Abstract: This paper presents a model for three-dimensional, heavy vehicle-pavement-foundation coupled system, which is modelled as a seven-DOF vehicle moving along a simply supported double-layer rectangular thin plate on a linear viscoelastic foundation. The vertical tyre force is described by a single point-contact model, while the pavement-foundation is modelled as a double-layer plate on a linear viscoelastic foundation. Using the Galerkin method and quick direct integral method, the dynamical behaviour of the vehicle-pavement-foundation coupled system is investigated numerically and compared with that of traditional vehicle system and pavement system. The effects of coupling action on vehicle body vertical acceleration, suspension deformations, tyre forces and pavement displacements are also obtained. The investigation shows that the coupling action could not be neglected even on a smooth road surface, such as highway. Thus, it is necessary to investigate the dynamics of vehicle and pavement simultaneously based on the vehicle-pavement-foundation coupled system.

Effect of curved track support failure on vehicle derailment

Abstract: In order to investigate the effect of curved track support failure on railway vehicle derailment, a coupled vehicle–track dynamic model is put forward. In the model, the vehicle and the structure under rails are, respectively, modelled as a multi-body system, and the rail is modelled with a Timoshenko beam rested on the discrete sleepers. The lateral, vertical, and torsional deformations of the beam are taken into account. The model also considers the effect of the discrete support by sleepers on the coupling dynamics of the vehicle and track. The sleepers are assumed to move backward at a constant speed to simulate the vehicle running along the track at the same speed. In the calculation of the coupled vehicle and track dynamics, the normal forces of the wheels/rails are calculated using the Hertzian contact theory and their creep forces are determined with the nonlinear creep theory by Shen et al [Z.Y. Shen, J.K. Hedrick, and J.A. Elkins, A comparison of alternative creep-force models for rail vehicle d...

Staying within the nullcline boundary for vehicle envelope control using a sliding surface

Abstract: Envelope control has been implemented successfully in aircraft for over a decade to assist pilots in stabilising their planes. With current advances in sideslip angle and friction coefficient estimation, envelope control can now be applied to the automotive industry as well. Using full state estimation of yaw rate and sideslip angle, stability controllers can assist the driver by keeping the vehicle within a safe region of the planar state space. This paper discusses the physical phenomena that must be taken into account when choosing an envelope and details a specific choice of envelope comprised of the yaw acceleration nullcline and the maximum rear slip angle limits. The vehicle is kept within the envelope using a computationally simple sliding surface control scheme. Experimental data show the success of the controller, which is implemented on a vehicle through the use of steer-by-wire.

Extending Collision Avoidance Methods to Consider the Vehicle Shape, Kinematics, and Dynamics of a Mobile Robot

Abstract: Most collision avoidance methods do not consider the vehicle shape and its kinematic and dynamic constraints, assuming the robot to be point-like and omnidirectional with no acceleration constraints. The contribution of this paper is a methodology to consider the exact shape and kinematics, as well as the effects of dynamics in the collision avoidance layer, since the original avoidance method does not address them. This is achievable by abstracting the constraints from the avoidance methods in such a way that when the method is applied, the constraints already have been considered. This study is a starting point to extend the domain of applicability to a wide range of collision avoidance methods.

Stability control for a mobile manipulator using a potential method

Abstract: Many future applications of robotic systems will require that manipulators perform operations while being carried by moving vehicles. However, such a vehicle mounted mobile manipulator can be unstable or even tip over. Previous work on stability control hardly considered the dynamics and environmental disturbances. The stability of a mobile manipulator has a close relation with the vehicle motion, manipulator motion and posture, and end-effector force. To evaluate the stability for a mobile manipulator, the concepts about stability, such as the stability degree and the valid stable region based on the zero moment point (ZMP) criterion have already been proposed. In this paper, as a control scheme for maintaining or recovering stability, the method of ZMP path planning by a stability potential field is presented, in which the concepts of the goal state and prohibitive state of stability are outlined. A motion planning algorithm is then formulated, which controls the manipulator in order to maintain the stability of the whole system while the vehicle is moving along a given trajectory. >