Vehicle dynamics

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

Second-Order Dynamic Sliding-Mode Control for Nonminimum Phase Underactuated Hypersonic Vehicles

Abstract: This paper deals with the second-order dynamic sliding-mode control (SODSMC) problem for nonminimum phase underactuated hypersonic vehicles. First, the underactuated hypersonic vehicle attitude control model is introduced. The normal form and the nonminimum phase nature for the vehicle are discussed. Thus, the nonminimum phase system is divided into the minimum phase subsystem and the nonminimum phase subsystem via the system decomposition approach. Second, the SODSMC scheme is developed. The conventional sliding-mode controller and the second-order dynamic sliding-mode controller are designed for the two subsystems. Besides, the dynamic sliding manifold is provided for the nonminimum phase subsystem. Simulation results for the nonminimum phase underactuated hypersonic vehicle are presented to demonstrate the effectiveness and robustness of the proposed control scheme.

A Global Tracking Controller for Underactuated Aerial Vehicles: Design, Analysis, and Experimental Tests on Quadrotor

Abstract: This paper investigates the global tracking control of underactuated aerial vehicles. In particular, the globally exponentially stable attitude tracking controller serving as the inner loop of the overall controller is investigated. It can avoid the common problems that may be accompanied by other attitude controllers, such as singularity and unwinding. In order to overcome the topological obstacles of global control on $SO(3)$ , rotational motion of a rigid body is expressed in the exponential coordinate restricted in a compact domain. We then construct a hybrid tracking error dynamics whose states are all represented in Euclidean space. The geometric properties of the state space are mathematically analyzed. The tracking controller of underactuated aerial vehicles is, thus, designed based on the hybrid tracking error dynamics. The global exponential stability of the closed-loop attitude subsystem, as well as the global asymptotical stability of the closed-loop overall system under assumptions, is analyzed using Lyapunov's method strictly. These properties are demonstrated by simulation results. The proposed controller is also implemented and tested on our self-developed quadrotor, showing the feasibility of the controller in realtime applications.

System dynamics and long-term behaviour of railway vehicles, track and subgrade

Abstract: The DFG Priority Programme 'System Dynamics and Long-Term Behaviour of Vehicle, Track and Subgrade'.- Invited Lectures.- Vehicle/Track Interaction Optimisation within Spoornet.- Active Suspension Technology and its Effect upon Vehicle-Track Interaction.- Rolling-Contact-Fatigue and Wear of Rails: Economic and Technical Aspects.- Vehicle Dynamics.- System Dynamics of Railcars with Radial- and Lateralelastic Wheels.- Distributed Numerical Calculations of Wear in the Wheel-Rail Contact.- Modeling and Simulation of the Mid-Frequency Behaviour of an Elastic Bogie.- Wavy Wear Pattern on the Tread of Railway Wheels.- Rotor Dynamics and Irregular Wear of Elastic Wheelsets.- Contact, Friction, Wear.- On the Numerical Analysis of the Wheel-Rail System in Rolling Contact.- Experimental Analysis of the Cyclic Deformation and Damage Behavior of Characteristic Wheel and Rail Steels.- Friction and Wear of Tractive Rolling Contacts.- Model-Based Validation within the Rail-Wheel-Subgrade Modeling.- Track Dynamics.- Monitoring the Dynamics of Railway Tracks by Means of the Karhunen-Loeve-Transformation.- Combined Modelling of Discretely Supported Track Models and Subgrade Models - Vertical and Lateral Dynamics.- Measurement and Modelling of Resilient Rubber Rail-Pads.- Model-Based Investigation of the Dynamic Behaviour of Railway Ballast.- The Dynamics of Railway Track and Subgrade with Respect to Deteriorated Sleeper Support.- Subgrade Dynamics.- Numerical Model and Laboratory Tests on Settlement of Ballast Track.- Track Settlement Due to Cyclic Loading with Low Minimum Pressure and Vibrations.- Simulation of the Dynamic Behavior of Bedding-Foundation-Soil in the Time Domain.- Dynamic Behavior of Railway Track Systems Analyzed in Frequency Domain.- Experimental and Numerical Investigations on the Track Stability.- Experimental Investigation and Numerical Modelling of Soils and Ballast under Cyclic and Dynamic Loading.- 3D-Simulation of Dynamic Interaction Between Track and Layered Subground.- Rigid Body Dynamics of Railway Ballast.- A Comparative Study of Results from Numerical Track-Subsoil Calculations.

An Efficient Minimum-Time Trajectory Generation Strategy for Two-Track Car Vehicles

Abstract: In this paper, we propose a novel approach to compute minimum-time trajectories for a two-track car model, including tires and (quasi-static) longitudinal and lateral load transfer. Given the car model and a planar track, including lane boundaries, our goal is to find a trajectory of the car minimizing the traveling time subject to steering and tire limits. Moreover, we enforce normal force constraints to avoid wheel liftoff. Based on a projection operator nonlinear optimal control technique, we propose a minimum-time trajectory generation strategy to compute the fastest car trajectory. Numerical computations are presented on two testing scenarios, a 90° turn and a real testing track. The computations allow us to both demonstrate the efficiency and accuracy of the proposed approach and highlight important features of the minimum-time trajectories. Finally, we integrate our strategy into a commercial vehicle dynamics software, thus computing minimum-time trajectories for a complex multibody vehicle model. The matching between the predicted trajectory and the one of the commercial toolbox further highlights the effectiveness of the proposed methodology.