scispace - formally typeset
Search or ask a question
Topic

Vehicle dynamics

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


Papers
More filters
Journal ArticleDOI
TL;DR: The application to the assembly line of the AGV with different payloads to track the circular and piecewise straight-line paths by the proposed HIFDSMC is compared with the hierarchical fuzzy decentralized PTC.
Abstract: A hierarchically improved fuzzy dynamical sliding-model control (HIFDSMC) is presented to address the autonomous ground vehicle (AGV) path tracking problem. The proposed controller has two portions: one is the virtual desired input (VDI), and the second is the path tracking control (PTC). In addition to the equivalent control in VDI and PTC, an improved fuzzy dynamical sliding-mode control (IFDSMC) is designed to deal with the system uncertainties, e.g., different payloads. Contributions of this paper include the following four parts: 1) Based on the nominal system response, the fuzzy rules and scaling factors of the IFDSMCs in the VDI and PTC are easily chosen. In contrast, a conventional fuzzy logic control approach requires more trial-and-error tuning to obtain a satisfactory performance. 2) The proposed HIFDSMC possesses the tuning mechanism (the coefficients of two sliding surfaces, the scaling factors in indirect and direct modes, and the fine tuning in fuzzy table) such that the uncertainties are tackled without a larger computational burden. 3) The stability of the closed-loop system is verified by the Lyapunov stability with hierarchical concept. 4) Different payloads not at the mass center of the AGV (e.g., greater than 25% in the total weight of the AGV) are tackled by the IFDSMCs to obtain a satisfactory performance. Finally, the application to the assembly line of the AGV with different payloads to track the circular and piecewise straight-line paths by the proposed HIFDSMC is compared with the hierarchical fuzzy decentralized PTC.

111 citations

Journal ArticleDOI
TL;DR: When commercially available test motor is adopted as a drivetrain of hybrid vehicle, the need to figure out which drive train configuration would be best for specific purpose is figured out.
Abstract: If the concept of Hardware-in-the-Loop (HIL) is applied to component testing, characteristic of component of hybrid electric vehicle in real vehicle environment can be evaluated without actually installing that component in real vehicle. In this paper, when commercially available test motor is adopted as a drivetrain of hybrid vehicle, we need to figure out which drive train configuration would be best for specific purpose. The characteristic of the motor when it is installed in the vehicle at different drive train and driving mode can be simulated and actual characteristic can be measured. Also both results can be compared. For the hardware characteristic measurement, test facility which consists of vehicle simulator and dynamometer is required. In this case, vehicle controller in the vehicle simulator is used as a vehicle controller and dynamometer is used to simulate vehicle dynamics. Two drive train types, 4-motor series, and 2-motor parallel type are proposed. Vehicle speed tracks driving cycle speed command well in both simulation and HIL implementation.

110 citations

Journal ArticleDOI
TL;DR: Simulation results show that the proposed algorithm is capable of safely exploiting the dynamic limits of the vehicle while navigating the vehicle through sensed obstacles of different sizes and numbers and can significantly improve performance by allowing navigation of obstacle fields that would otherwise not be cleared with steering control alone.
Abstract: This paper presents a model predictive control-based obstacle avoidance algorithm for autonomous ground vehicles at high speed in unstructured environments The novelty of the algorithm is its capability to control the vehicle to avoid obstacles at high speed taking into account dynamical safety constraints through a simultaneous optimization of reference speed and steering angle without a priori knowledge about the environment and without a reference trajectory to follow Previous work in this specific context optimized only the steering command In this paper, obstacles are detected using a planar light detection and ranging sensor A multi-phase optimal control problem is then formulated to simultaneously optimize the reference speed and steering angle within the detection range Vehicle acceleration capability as a function of speed, as well as stability and handling concerns such as preventing wheel lift-off, are included as constraints in the optimization problem, whereas the cost function is formulated to navigate the vehicle as quickly as possible with smooth control commands Simulation results show that the proposed algorithm is capable of safely exploiting the dynamic limits of the vehicle while navigating the vehicle through sensed obstacles of different sizes and numbers It is also shown that the proposed variable speed formulation can significantly improve performance by allowing navigation of obstacle fields that would otherwise not be cleared with steering control alone

110 citations

Journal ArticleDOI
TL;DR: In this paper, a detailed multibody model of the catenary and the pantograph is presented for the identification of the dynamic behaviour of the pantographs and of the interaction phenomena in the catenaries of high-speed trains due to the action of aerodynamics forces.
Abstract: Most of the high-speed trains in operation today have the electrical power supply delivered through the pantograph-catenary system. The understanding of the dynamics of this system is fundamental since it contributes to decrease the number of incidents related to these components, to reduce the maintenance and to improve interoperability. From the mechanical point of view, the most important feature of the pantograph-catenary system consists in the quality of the contact between the contact wire of the catenary and the contact strips of the pantograph. The catenary is represented by a finite element model, whereas the pantograph is described by a detailed multibody model, analysed through two independent codes in a co-simulation environment. A computational procedure ensuring the efficient communication between the multibody and finite element codes, through shared computer memory, and suitable contact force models were developed. The models presented here are contributions for the identification of the dynamic behaviour of the pantograph and of the interaction phenomena in the pantograph-catenary system of high-speed trains due to the action of aerodynamics forces. The wind forces are applied on the catenary by distributing them on the finite element mesh. Since the multibody formulation does not include explicitly the geometric information of the bodies, the wind field forces are applied to each body of the pantograph as time-dependent nonlinear external forces. These wind forces can be characterised either by using computational fluid dynamics or experimental testing in a wind tunnel. The proposed methodologies are demonstrated by the application to real operation scenarios for high-speed trains, with the purpose of defining service limitations based on train and wind speed combination.

110 citations

Journal ArticleDOI
TL;DR: A technique that complements path-tracking controller design procedures based on exact linearization by associating to it an auxiliary (ghost) vehicle whose model can be exactly linearized and whose behavior satisfies certain compatibility conditions is proposed.
Abstract: A technique that complements path-tracking controller design procedures based on exact linearization is proposed. The objective is to make these procedures applicable to vehicles whose kinematic model is not necessarily exactly linearizable (as a tractor-trailer with off-axle hitching or a load-haul-dump mining vehicle). A key element of our approach is to control a inexactly linearizable vehicle by associating to it an auxiliary (ghost) vehicle whose model can be exactly linearized and whose behavior satisfies certain compatibility conditions. Main features of this approach are illustrated by considering articulated vehicles with off-axle hitching (which are not exactly-linearizable), and by focusing attention to a geometric path-tracking design procedure recently developed by Sampei et al. (1993, 1995).

110 citations


Network Information
Related Topics (5)
Control theory
299.6K papers, 3.1M citations
89% related
Control system
129K papers, 1.5M citations
87% related
Optimal control
68K papers, 1.2M citations
84% related
Robustness (computer science)
94.7K papers, 1.6M citations
84% related
Linear system
59.5K papers, 1.4M citations
83% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023167
2022478
2021620
2020811
2019749
2018749