1,743 results on '"VEHICLE models"'
Search Results
2. Mathematical modeling for vehicle assignment problem in online transportation.
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Supian, Sudradjat and Megantara, Tubagus Robbi
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URBAN transportation , *ASSIGNMENT problems (Programming) , *VEHICLE models , *MATHEMATICAL models , *RIDESHARING services , *PUBLIC transit , *RIDESHARING - Abstract
The general public often uses local public transportation to travel from one place to another without having to have a vehicle first. Innovations supported by science and technology can make local transportation accessible via smartphones connected to the internet, often called online transportation. Online transportation makes it easy for users to identify drivers and find smartphone service rates. Online transportation is divided into two types based on the vehicle-shared scheme: ride-hailing and ride-sharing. Ride-hailing does not allow one group of passengers to share rides and incentives with another, while ride-sharing allows it. Ride-hailing is the development of motorcycle taxis and taxis, while ride-sharing is the development of urban transportation. Online transportation companies in Indonesia more often use the ride-hailing scheme because it provides convenience in privacy. Ride-hailing has several essential components, including the assignment of vehicles to pick up groups of passengers, distribution of vehicles to balance supply and demand, and the provision of service rates. This study describes the mathematical modelling for strategy vehicle assignment in ride-hailing. The assignment is allocating resources to meet demand as efficiently as possible. Numerical simulation is used to evaluate models' performance reactively against real-world request data. Percentage serviced requests, travel delay time, and pick-up distance are shown based on each model's numerical simulation results. The model selection for the ride-hailing system can be determined based on the numerical simulation results. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Performance of vehicle direction behavior on turning conditions by adding braking force proportion control.
- Author
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Atmika, I. Ketut Adi and Suriadi, I. Gusti Agung Kade
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ANTILOCK brake systems in automobiles , *PLANT performance , *BRAKE systems , *AUTOMOTIVE engineering , *VEHICLE models - Abstract
The performance of vehicle direction stability both on straight roads and turning roads is one of the important aspects to be considered in designing automotive products as a whole. In straight road conditions, an antilock brake system has been developed or better known as the Antilock Breaking System (ABS), but in turning conditions, the standard ABS performance is less than optimal to overcome oversteer or understeer vehicle conditions. The less optimal performance of vehicle direction stability is due to the magnitude of the braking force of each wheel is still the same while in turning conditions the braking force requirements of each wheel are not the same. One strategy to overcome these weaknesses is to control the proportion of braking force on each wheel. The research was conducted by formulating the physical model of the system into a mathematical model, then simulating it with a Simulink matlab. The braking force proportion control system model, and the vehicle model are made completely, then integrated into the vehicle direction stability performance plant/system. The simulation results show that at a fairly high speed of 80 km/hour the braking system with control of the proportion of braking force is still quite good, while the standard ABS at speeds above 60 km/hour tends to oversteer. [ABSTRACT FROM AUTHOR]
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- 2024
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4. Мultiobjective H2-control design for semi-active vehicle suspension with Magneto-Rheological damper – Part1: Linear quadratic regulator synthesis.
- Author
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Genov, Julian Asenov, Kralov, Ivan Mladenov, and Angelov, Ivo Angelov
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MOTOR vehicle springs & suspension , *REAL-time control , *VEHICLE models , *GAME theory , *COMPUTER simulation - Abstract
The paper discussed the problems related to a linear quadratic regulator (LQR) synthesis for the control implementation in a semi-active car suspension. The control is a combination between the state's feedback and compensation by the excitation. For this purpose, the state and the input disturbance are reconstructed using the observed variables. The physical nonlinearities of the controllable magneto-rheological semi-active damper are considered. The regulator structure also includes a model of the inverse magneto-rheological damper, based on neural networks. A "Quarter car model" is used for the vehicle suspension modelling as enough adequate and appropriate for real-time control. The main contribution of the research is the approach for determining the weight matrices of the regulators, based on a formulated multicriteria problem, and solved based on the Game Theory. Numerical simulations are given, allowing for comparison of the results, and confirming the effectiveness of the presented approach. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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5. Applied of model vehicle sharing system with modified model passive regulation lower bound for mobility improvement.
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Arisha, Bella and Nengsih, Titin Agustin
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VEHICLE models , *SPACE vehicles , *SPACE stations , *LINEAR programming , *INTEGER programming - Abstract
In this paper use model vehicle sharing system. Formulate modified model passive regulation lower Bound. This research focused on One-Way Vehicle Sharing System. It is the system that user can rent and return vehicle at any station. The modified model passive regulation lower bound aims to minimize total of excess time for all user so there is vehicle in initial station and there is parking space in destination station. So the user did not need to wait to long until vehicle available in initial station or parking space available in destination station. In real life often there is no vehicle to rent and there is no parking space to park vehicle that had been rented. So in this paper will analyze total excess time for all users. Model formulated as Mix Integer Linear Programming. To formulate and solve model used Lingo. 17. The result show minimum total excess time for all users is 10,25 minutes. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Direct Yaw Moment Control for Distributed Drive Electric Vehicles Based on Hierarchical Optimization Control Framework.
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Hu, Jie, Zhang, Kefan, Zhang, Pei, and Yan, Fuwu
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STANDARD deviations , *MOTOR vehicle driving , *PARTICLE swarm optimization , *VEHICLE models , *PAVEMENTS - Abstract
Direct yaw moment control (DYC) can effectively improve the yaw stability of four-wheel distributed drive electric vehicles (4W-DDEVs) under extreme conditions, which has become an indispensable part of active safety control for 4W-DDEVs. This study proposes a novel hierarchical DYC architecture for 4W-DDEVs to enhance vehicle stability during ever-changing road conditions. Firstly, a vehicle dynamics model is established, including a two-degree-of-freedom (2DOF) vehicle model for calculating the desired yaw rate and sideslip angle as the control target of the upper layer controller, a DDEV model composed of a seven-degree-of-freedom (7DOF) vehicle model, a tire model, a motor model and a driver model. Secondly, a hierarchical DYC is designed combining the upper layer yaw moment calculation and low layer torque distribution. Specifically, based on Matlab/Simulink, improved linear quadratic regulator (LQR) with weight matrix optimization based on inertia weight cosine-adjustment particle swarm optimization (IWCPSO) is employed to compute the required additional yaw moment in the upper-layer controller, while quadratic programming (QP) is used to allocate four motors' torque with the optimization objective of minimizing the tire utilization rate. Finally, a comparative test with double-lane-change and sinusoidal conditions under a low and high adhesion road surface is conducted on Carsim and Matlab/Simulink joint simulation platform. With IWCPSO-LQR under double-lane-change (DLC) condition on a low adhesion road surface, the yaw rate and sideslip angle of the DDEV exhibits improvements of 95.2%, 96.8% in the integral sum of errors, 94.9%, 95.1% in the root mean squared error, and 78.8%, 98.5% in the peak value compared to those without control. Simulation results indicate the proposed hierarchical control method has a remarkable control effect on the yaw rate and sideslip angle, which effectively strengthens the driving stability of 4W-DDEVs. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Collision Risk Warning Model for Construction Vehicles Based on YOLO and DeepSORT Algorithms.
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Zhang, Fan, Liu, Hongbo, Chen, Zhihua, Wang, Longxuan, Zhang, Qian, and Guo, Liulu
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WARNINGS , *COLLISIONS at sea , *VEHICLE models , *VIDEO surveillance , *CONSTRUCTION projects , *BUILDING design & construction , *ALGORITHMS - Abstract
Collision accidents of construction vehicles frequently occur during the construction of building projects. It is difficult to warn of collision risk efficiently by using the safety control methods of on-site inspection and viewing surveillance video. Therefore, a novel collision risk warning model for construction vehicles is proposed in this paper. The model comprises a state awareness module and a collision risk assessment module. In the state awareness module, the YOLOv7 algorithm is used to identify and locate construction vehicles. The DeepSORT algorithm is used for the real-time tracking of construction vehicles. Finally, the state awareness module obtains a wealth of sensing information and provides it to the collision risk assessment module. In the collision risk assessment module, the speed assessment method and the minimum safety distance assessment method of construction vehicles are innovatively proposed and compiled. In the speed assessment method, the speed of construction vehicles is calculated and speeding warnings are performed using the transformation matrix between latitude and longitude coordinates and image pixel coordinates. In the minimum safety distance assessment method, the original surveillance picture is converted into a bird's eye view (BEV) of the world coordinate system through inverse perspective mapping (IPM). Then the distance of all construction vehicles is traversed, and the visual warning of the minimum safe distance is provided. The effectiveness and robustness of this collision risk warning model were verified by taking three practical projects in different construction stages as examples. The research results show that the mean average precision (mAP@0.5:0.95) of the construction vehicles collision risk warning model can reach 89.10%, and it has a good tracking effect and an efficient collision risk warning strategy. [ABSTRACT FROM AUTHOR]
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- 2024
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8. Dynamical analysis of a fractional-order nonlinear two-degree-of-freedom vehicle system by incremental harmonic balance method.
- Author
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Chang, Yujian, Zhu, Yuxiao, Li, Yongkuan, and Wang, Meiqi
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NONLINEAR analysis , *VISCOELASTIC materials , *POWER series , *NONLINEAR systems , *MOTOR vehicle springs & suspension , *VEHICLE models , *SUSPENSION systems (Aeronautics) - Abstract
At present, there are few studies considering both nonlinear and fractional characteristics of suspension in vehicle systems. In this paper, a fractional nonlinear model of a quarter vehicle with two-degree-of-freedom (2-DOF) is innovatively proposed to describe the suspension system containing the viscoelastic material metal rubber. Given the lack of a general calculation scheme for the multi-degree-of-freedom fractional-order incremental harmonic balance method (IHBM), a general calculation scheme for the 2-DOF incremental harmonic balance method for nonlinear systems with fractional order is derived. The nonlinear dynamical properties of the presented model are acquired using this method. The accuracy of the proposed method is verified through a comparison with the power series expansion method. Afterward, the effects of the various parameters on the dynamic performance are analyzed. The vibration peak value of the fractional-order model is significantly higher than that of the integer-order model (IOM). Therefore, the suspension parameters should be designed with a margin when using IOM. [ABSTRACT FROM AUTHOR]
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- 2024
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9. NMPC Design for Local Planning of Automated Vehicle with Less Computational Consumption.
- Author
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Zhang, B., Fan, P., Tang, S., Gao, F., and Zhen, S.
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AUTONOMOUS vehicles , *AUTOMATED planning & scheduling , *NUMERICAL analysis , *VEHICLE models , *PREDICTION models - Abstract
Nonlinear Model Predictive Control (NMPC) is effective for local planning of automated vehicles, especially when there exist dynamical objects and multipe requirements. But it requires many computation resources for numerical optimization, which limits its practical application becase of the limited power of onboard unit. To extend the application range of the NMPC based local planner, the coupled nonlinear vehicle dynamics model is adopted based on the numerical analysis, which conversely requires much more discretization poits for acceptable accuracy. For better computation efficiency, Lagrange polynomials are used to discretize the vehicle dynamics model and objective function with less points and fine numerical accuracy. Furthermore, an adaptive strategy is designed to determine the order of Lagrange polynomials according to running state by numerical analysis of discretization error. Both acceleration effect and performance of the local planner designed by NMPC are validated by experimental tests under scenarios with multiple dynamical obstacles. The test results show that compared with the original one the accuracy and efficiency are improved by 74% and 60%, respectively. [ABSTRACT FROM AUTHOR]
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- 2024
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10. Model-free autonomous control of four-wheel steering using artificial flow guidance.
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Liu, Qingwei, Gordon, Timothy, and Rahman, Shammi
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GEOMETRICAL constructions , *VECTOR fields , *RELATIVE motion , *REAL-time computing , *AUTONOMOUS vehicles , *VEHICLE models , *AXLES - Abstract
Four-wheel steering (4WS) is an effective technique to improve handling performance and lateral stability of road vehicles. Conventionally, controllers utilise the driver's actions and vehicle dynamics to coordinate front and rear-axle steering. This paper proposes a novel approach for 4WS controller design, based on the concept of Artificial Flow Guidance (AFG), which relies on a spatially distributed motion reference through a two-dimensional vector field. This field provides high-level guidance while lower-level steering controllers to control axle centres motions relative to the flow. These flow vectors, computed in real-time via simple geometric construction, can be pre-computed globally to evaluate the guidance algorithm's efficacy. When controlling only the front axle, this same approach can function as an autonomous driving system. Relying solely on a spatial reference field and control targets' velocities enables the controller to work in a simple and robust fashion, without using a reference vehicle dynamics model or lengthy parameter tuning. The proposed approach's effectiveness is validated through co-simulation with MATLAB/Simulink and the CarMaker simulation platform. AFG control performance is found to be at least comparable to that of more complex 4WS controllers using methods such as MPC; in the cases considered, AFG provides superior path-tracking performance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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11. Implementation and design of ultra-local model-based control strategy for autonomous vehicles.
- Author
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Hegedűs, Tamás, Fényes, Dániel, Szabó, Zoltán, Németh, Balázs, Lukács, Loránd, Csikja, Rudolf, and Gáspár, Péter
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AUTONOMOUS vehicles , *LINEAR systems , *VEHICLE models , *AUTOMOBILE industry - Abstract
The paper presents a novel control strategy for autonomous vehicles, which can effectively handle the nonlinear effects and uncertainties of the controlled system. This solution is based on a new formulation of the ultra-local model-based control approach. This method can deal with the unknown dynamics and other uncertainties of the vehicle without any further measurement or complex modelling process. The control methods require a reduced-complexity nominal linear model of the system, and the unknown part is continuously estimated by the proposed ultra-local model. The proposed control-oriented vehicle modelling method leads to an increased performance level of vehicle motion. The effectiveness of the proposed method through a high-fidelity vehicle simulator (CarMaker) is illustrated. Moreover, the operation of the control through its implementation on a test vehicle of ThyssenKrupp is also demonstrated. [ABSTRACT FROM AUTHOR]
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- 2024
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12. Modelling, hardware-in-the-loop tests and numerical simulation of magneto-rheological semi-active primary suspensions in a railway vehicle.
- Author
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Fu, Bin, Di Gialleonardo, Egidio, Liu, Binbin, and Bruni, Stefano
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RAILROAD trains , *MOTOR vehicle springs & suspension , *COMPUTER simulation , *HIGH speed trains , *MAGNETORHEOLOGY , *VEHICLE models - Abstract
Semi-active primary suspensions are an effective means of improving ride quality in high-speed railway vehicles in relation to the mitigation of car-body bending vibration. In this paper, prototype magnetorheological (MR) dampers are tested and the results are used to define a mathematical model of the dampers. Then, three control schemes for semi-active primary suspensions are proposed: Skyhook, LQG and Mix-1-Sensor, and their performance is assessed by means of Hardware-In-the-Loop (HIL) tests considering a simple quarter-vehicle model which is run on a real-time board and set in interaction with one physical MR damper. The results show that all three considered control strategies lead to a reduction of car-body vibration by around 30% and a very good agreement is found between HIL tests and numerical simulations in which the physical damper is replaced by the mathematical damper model. The damper model is finally interfaced with a flexible multi-body model of the complete vehicle to provide further assessment of semi-active control. The results of the latter simulations show that the semi-active suspension could provide an improvement of the $ {N_{mvz}} $ N mvz ride quality index in the order of 40–45% with respect to the passive vehicle for all three control schemes. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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13. The random dynamic performances of EMUs with polygonal damages.
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Awel, Momhur and YongXiang, Zhao
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BOGIES (Vehicles) , *WIND pressure , *IMPACT loads , *ELASTIC deformation , *VEHICLE models , *SYSTEM dynamics - Abstract
Polygonalization is a typical non-uniform wear phenomenon that affects the performance and comfort of the vehicle/track system. Therefore, the vehicle system performance could be strictly troubled by polygonal damage close to the wheel circumference at the wheel/rail contact. A 3D vehicle/track an EMU type train consisting of 8 coupled vehicles model has been established. The coupled model car body and bogie frame are considered rigid and integrated with the flexible wheelset, rail, and slab track to investigate the elastic deformation caused by the impact load induced by the wheel polygonalization. The flexible track can be incorporated into the multi-body vehicle model using the movable reference frame formulation. Uncertainty parameters are presented, such as passenger weight, wind force, coefficient friction, and suspension variation. The proposed research is validated based on the existing research work and shows excellent agreement. The simulation result deliberated the vertical wheel-rail force, wheelset acceleration, rail acceleration, rail displacement, and slab track acceleration. The results of this study show that as the wheel polygonal damage amplitude increase, the value of wheel/rail normal forces and the dynamic vibrational response of the wheelset axle increase. Additionally, polygonal wear-induced impact stresses may cause the wheelset axle to resonate. When wheel polygonal damage amplitude and uncertainty parameters are corporate into the system dynamics, the maximum magnitude of the wheelset, rail, and slab track acceleration increases. Besides, the train failure degree is comparable to the polygonised wheel harmonic order, defect parameters, and amplitude of out-of-roundness. [ABSTRACT FROM AUTHOR]
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- 2024
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14. An accurate trajectory tracking method for low-speed unmanned vehicles based on model predictive control.
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Wang, Lifen, Chen, Sizhong, and Ren, Hongbin
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AUTONOMOUS vehicles , *VEHICLE models , *PREDICTION models , *REMOTELY piloted vehicles , *CURVATURE - Abstract
Trajectory tracking on a low-speed vehicle using the model predictive control (MPC) algorithm usually assumes a simple road terrain. This assumption does not correspond to the actual road situation, leading to low tracking accuracy. Therefore, a trajectory tracking method considering road curvature based on MPC is proposed in this paper. In this method, the controller can automatically switch between MPC types. Linear model predictive control (LMPC) is selected for small road curvatures, while nonlinear model predictive control (NMPC) is employed for large road curvatures. In addition, the NMPC algorithm in this work considers the effect of road curvature on tracking accuracy, making it suitable for tracking time-varying curvature roads. To verify the feasibility of the algorithm, simulation comparisons with the basic MPC model were carried out at different testing roads and vehicle longitudinal speeds. The results indicate that the method significantly improves trajectory tracking accuracy, all while ensuring real-time calculations. The intelligent switching capability of control models based on road curvature allows its application to track trajectories on arbitrarily complex roads. [ABSTRACT FROM AUTHOR]
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- 2024
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15. Carrier-Free Ultra-Wideband Sensor Target Recognition in the Jungle Environment.
- Author
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Li, Jianchao, Zhang, Shuning, Zhu, Lingzhi, Chen, Si, Hou, Linsheng, Li, Xiaoxiong, and Chen, Kuiyu
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JUNGLES , *DETECTORS , *SYSTEM identification , *ECHO , *NETWORK performance , *VEHICLE models - Abstract
Carrier-free ultra-wideband sensors have high penetrability anti-jamming solid ability, which is not easily affected by the external environment, such as weather. Also, it has good performance in the complex jungle environment. In this paper, we propose a jungle vehicle identification system based on a carrier-free ultra-wideband sensor. Firstly, a composite jungle environment with the target vehicle is modeled. From this model, the simulation obtains time-domain echoes under the excitation of carrier-free ultra-wideband sensor signals in different orientations. Secondly, the time-domain signals are transformed into MTF images through the Markov transfer field to show the statistical characteristics of the time-domain echoes. At the same time, we propose an improved RepVGG network. The structure of the RepVGG network contains five stages, which consist of several RepVGG Blocks. Each RepVGG Block is created by combining convolutional kernels of different sizes using a weighted sum. We add the self-attention module to the output of stage 0 to improve the ability to extract the features of the MTF map and better capture the complex relationship between characteristics during training. In addition, a self-attention module is added before the linear layer classification output in stage 4 to improve the classification accuracy of the network. Moreover, a combined cross-entropy loss and sparsity penalty loss function helps enhance the performance and accuracy of the network. The experimental results show that the system can recognize jungle vehicle targets well. [ABSTRACT FROM AUTHOR]
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- 2024
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16. A tyre wear modelling approach for vehicle dynamics simulation and control-oriented analyses with application to motorcycles.
- Author
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Radrizzani, Stefano, Panzani, Giulio, and Savaresi, Sergio M.
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VEHICLE models , *MOTORCYCLING , *MOTORCYCLES , *HYPERSONIC planes , *KINEMATICS - Abstract
To increase vehicle dynamics modelling accuracy in simulation environments, in this work, we propose a model, where the mutual influence of the vehicle dynamics and tyre wear is taken into account. In this context, simulation-oriented models aim at representing the main features of the vehicle dynamics, while keeping the complexity low, making them suitable for control-oriented analyses and design. The wear model quantifies tyre wear as a tyre mass loss depending on the tyre-road interaction, derived from the vehicle dynamics and kinematics; then, the outcome of this model is consequently used to update the tyre friction characteristics, by modifying the main parameters of the Pacejka's magic formula. We also discuss the steps required to use the model in two-wheeled vehicles, where the roll dynamics plays an important role in the tyre wear. The main features of the developed model are discussed on a motorcycle, as a simulation case-study. [ABSTRACT FROM AUTHOR]
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- 2024
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17. Adaptive authority allocation for shared steering control considering social behaviours: a hybrid fuzzy approach with game-theoretical vehicle interaction model.
- Author
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Guo, Wenfeng, Cao, Haotian, Song, Xiaolin, Wang, Jianqiang, Zhao, Song, and Yi, Binlin
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VEHICLE models , *SOCIAL control , *AUTONOMOUS vehicles , *NASH equilibrium , *MOTOR vehicle driving , *PREDICTION models , *RIDESHARING - Abstract
In a typical traffic scenario, automated vehicles are required to interact with surrounding traffic participants, e.g. human-driven vehicles, pedestrians, etc. In this paper, a novel adaptive authority allocation strategy considering the social behaviours of surrounding vehicles is proposed for the shared steering control (SSC) of automated vehicles. First, a Koopman-based potential-field-driven distributed model predictive control (K-PF-DMPC) method is proposed for the modelling of vehicle interaction to describe surrounding vehicle's social behaviour. This method effectively deals with the nonlinearity embedded in the non-cooperative game-based vehicle interaction model, so that the analytical form of Nash equilibrium can be derived for a fast online solution. Then, the SSC system of the automated vehicle is implemented by a weighted summation method. To balance the driving performance and intervention degree while considering the surrounding vehicles' social behaviours, a hybrid fuzzy strategy (HFS) is proposed for allocating the control authority between the driver and automation. The value of authority allocation coefficient is calculated by fusing the outputs from two shared fuzzy controllers, i.e. the enhanced and weakened shared fuzzy controllers, in accordance to the belief of the surrounding vehicle's type. Several numerical simulations and driver-in-the-loop simulator experiments are conducted for validation. Results show that the proposed strategy can provide appropriate steering intervention to the driver owing to the consideration of the surrounding vehicle's social behaviour and obtains the best driver-automation collaboration performance compared with the comparative groups. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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18. A model predictive control trajectory tracking lateral controller for autonomous vehicles combined with deep deterministic policy gradient.
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Xie, Zhaokang, Huang, Xiaoci, Luo, Suyun, Zhang, Ruoping, and Ma, Fang
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PREDICTION models , *REINFORCEMENT learning , *ITERATIVE learning control , *AUTONOMOUS vehicles , *VEHICLE models , *PROBLEM solving - Abstract
To solve the problem of trajectory tracking lateral control in autonomous driving technology, a model predictive control (MPC) controller trajectory tracking lateral control method combined with a deep deterministic policy gradient algorithm (DDPG) is proposed in this paper. This method inputs the real-time state of the vehicle into DDPG to achieve real-time automatic optimization of the prediction time domain and control time domain parameters of the MPC controller, and then affects the specific performance of the MPC controller in trajectory tracking lateral control. Specifically, the state space, action space, and reward function of DDPG are defined, and the automatic driving trajectory tracking lateral controller is designed in combination with the vehicle dynamics model. To reduce the exploration space of DDPG and improve the training efficiency of the entire model, the technique of advantage-disadvantage experience separation and extraction is introduced. Finally, the proposed method was trained and verified in various scenarios, and compared with two other lateral control methods for autonomous driving. The results showed that the learning and training time of the trajectory tracking lateral control method based on DDPG-MPC was shorter than that of the DDPG-based method, and the evaluation indicators in the trajectory tracking control process were better than those of the DDPG-based method and original MPC-based method. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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19. A Novel Split-Type Two-Axle Vehicle Model for Bridge Indirect Measurement.
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Zhu, Jinsong and Shi, Teng
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VEHICLE models , *BRIDGES , *FREQUENCIES of oscillating systems , *ANALYTICAL solutions , *NUMERICAL analysis , *CONCEPTUAL design - Abstract
A split-type two-axle vehicle for bridge indirect measurement is proposed to address the deficiencies of single-axle and conventional two-axle vehicles. At first, the conceptual design of the split-type two-axle vehicle is put forth, and the analytical solution for the vehicle-bridge interaction (VBI) system response is derived. After that, the regularity of the vehicle frequency response function is studied, and the numerical analysis method is utilized to validate the analytical solution. Based on the theoretical findings, the vehicle frequency and speed are studied to investigate their impacts on extracting bridge frequencies from vehicle responses. The results indicate that a peak will form in the frequency response function (FRF) curves when the input frequency is near to the vehicle frequency. The single peak phenomenon will occur when the zero-point condition of the FRF from the contact point to the vehicle body is remarkably close to the second vibration frequency of the vehicle. It is preferable for the first frequency of the vehicle to be higher than that of the bridge since this helps to extract the bridge frequency. On the other hand, at low speeds (≤ 43.2km/h), higher vehicle speeds will result in a greater distance between the peaks of the left- and right-shifted frequencies of the bridge, wider frequency bands, and lower spectral resolution, which is not conducive to bridge frequency identification. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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20. Learning-Based Control of Autonomous Vehicles Using an Adaptive Neuro-Fuzzy Inference System and the Linear Matrix Inequality Approach.
- Author
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Sheikhsamad, Mohammad and Puig, Vicenç
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LINEAR matrix inequalities , *LINEAR systems , *AUTONOMOUS vehicles , *DRIVERLESS cars , *VEHICLE models , *RACING automobiles - Abstract
This paper proposes a learning-based control approach for autonomous vehicles. An explicit Takagi–Sugeno (TS) controller is learned using input and output data from a preexisting controller, employing the Adaptive Neuro-Fuzzy Inference System (ANFIS) algorithm. At the same time, the vehicle model is identified in the TS model form for closed-loop stability assessment using Lyapunov theory and LMIs. The proposed approach is applied to learn the control law from an MPC controller, thus avoiding the use of online optimization. This reduces the computational burden of the control loop and facilitates real-time implementation. Finally, the proposed approach is assessed through simulation using a small-scale autonomous racing car. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
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21. Robust tracking strategy for nonlinear connected vehicle cyber-physical systems.
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Yang, Yushi, Li, Meng, and Chen, Yong
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CYBER physical systems , *BACKSTEPPING control method , *AUTONOMOUS vehicles , *NONLINEAR systems , *ARTIFICIAL satellite tracking , *VALUES (Ethics) , *VEHICLE models - Abstract
This paper investigates the problem of tracking target control of a nonlinear system in the context of cyber-physical systems for connected autonomous vehicles with external unknown disturbances. A new robust tracking strategy via backstepping sliding-mode control is proposed. First, a connected nonlinear vehicle dynamical model with disturbances is constructed. Then, a disturbance observer is presented to approximate the unknown disturbances when the derivative of the disturbance is bounded. This paper has proved that the error of the observation can converge to zero in finite time. Third, a tracking control method is designed which combines the backstepping method with the sliding-mode method. According to the method, the estimated values of interference are used as a priori knowledge. Furthermore, the stability of the designed control strategy is demonstrated through using the Lyapunov theory. Finally, simulation experiments are presented to demonstrate the feasibility of the proposed approaches. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
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22. Integrated optimization of scheduling for unmanned follow-me cars on airport surface.
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Yuan, Dezhou, Zhu, Xinping, Zou, Yajun, and Zhao, Qing
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OPTIMIZATION algorithms , *AUTONOMOUS vehicles , *VEHICLE models , *SCHEDULING , *AUTOMOBILES , *AIRPORTS , *REMOTELY piloted vehicles - Abstract
To promote the application of automated vehicles in large airports, in this study, we present an integrated optimization method for scheduling Unmanned follow-me cars. The scheduling process is divided into three phases: Dispatch, Guidance, and Recycle. For the Dispatch phase, we establish a vehicle assignment model, to allocate the vehicle resource equitably. For the Guidance phase, we offer an quantitative way, to measure the spacing between Unmanned follow-me car and aircraft. To optimize the efficiency of airport operation in the three phases and ensure safety, the collaborative planning model, and the conflict prediction model are established. An improved grey wolf optimization algorithm is adopted to enhance the convergence speed and generalization performance. A case study at Ezhou Huahu Airport in China demonstrates the effectiveness of the methods. The results show that the model of collaborative planning can make the balance of path selection, Unmanned follow-me car's working time, and departure sequence. The convergence speed of the improved algorithm has been increased by 18.75%. The inequity index of vehicle assignment is only 0.015731, and the spatiotemporal distribution of conflicts is influenced by the airport's surface layout. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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23. Application of CNN-LSTM Model for Vehicle Acceleration Prediction Using Car-following Behavior Data.
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Tang, Shuning, Zou, Yajie, Zhang, Hao, Zhang, Yue, and Kong, Xiaoqiang
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ACCELERATION (Mechanics) , *CONVOLUTIONAL neural networks , *HIDDEN Markov models , *MOTOR vehicle driving , *VEHICLE models - Abstract
Accurate vehicle acceleration prediction is useful for developing reliable Advanced Driving Assistance Systems (ADAS) and improving road safety. The existence of driver heterogeneity magnifies the variations in acceleration data, leading to consequential impacts on the precision of vehicle acceleration prediction. However, few studies have fully considered the driver heterogeneity when predicting vehicle acceleration. To model the characteristics of individual drivers, this study first identifies the driving behavior semantics which is defined as the underlying patterns of driving behaviors. The analysis results from the coupled hidden Markov model (CHMM) are used to evaluate the driving behavior differences between different drivers by Wasserstein distance. Then the convolutional neural network (CNN) and long short-term memory (LSTM) network are applied to predict vehicle acceleration. To validate the accuracy of the proposed prediction framework, vehicle acceleration data in car-following conditions is extracted from the safety pilot model deployment (SPMD) dataset. The segmentation results indicate that the CHMM possesses a robust capacity for modeling driving behavior. The prediction results demonstrate that the proposed framework, which incorporates driver clustering before prediction, significantly improves the accuracy of predictions. And the CNN-LSTM outperforms the LSTM in predicting vehicle acceleration during car-following scenarios. The findings from this study can enhance the development of personalized functionalities within ADAS to promote its deployment, thereby improving its acceptance and safety. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. Typical motion-based modelling and tracking for vehicle targets in linear road segment.
- Author
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Hao, Xiaohui, Xia, Yuanqing, Yang, Hongjiu, and Zuo, Zhiqiang
- Subjects
- *
TRACKING radar , *LANE changing , *ORNSTEIN-Uhlenbeck process , *VEHICLE models , *ROADS - Abstract
In this paper, a typical motion-based modelling and tracking issue is investigated for vehicle targets in linear road segment by a variable structure multiple model (VSMM) method. Vehicle target motions in a road with multiple lanes are described by typical lane keeping and lane changing manoeuvres. To describe trajectories of typical manoeuvres, an Ornstein–Uhlenbeck process and a sine half-cycle are used to model lane keeping and lane changing motions in lateral direction, respectively. Note that starting point and length of lane changing motion are unknown in target tracking. Time-varying model sets are designed based on the current motion model with different motion parameters. A VSMM tracking frame is constructed to obtain target state estimates with time-varying model set. The effectiveness of the proposed typical motion-based tracking scheme is displayed by simulation results on road vehicle tracking. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. Evaluation of the strength performance of the steering system of hybrid off-road vehicles.
- Author
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Yue Li, Jinrong Fang, Song Li, and Zhihui Niu
- Subjects
- *
HYBRID electric vehicles , *TRAFFIC safety , *FAILURE mode & effects analysis , *MOTOR vehicle driving , *VEHICLE models , *OFF-road vehicles , *STEERING gear - Abstract
In response to the strength performance requirements of the new energy Off road Vehicle steering system, this article analyzes and studies the strength performance and failure modes of the new energy Off road Vehicle steering rod based on a certain new energy Off road Vehicle model through simulation, bench experiments, and vehicle strength testing teams. Based on various vehicle misuse conditions, the force law of the steering rod under different vehicle driving conditions was analyzed, and a load spectrum for the steering rod strength bench test was developed to meet the actual vehicle usage conditions. The results indicate that the steering rod strength failure is mainly manifested as bending failure of the compression rod under alternating tension and compression conditions. Finally, based on the stability principle of the compression rod, the requirements for the strength performance index of the steering rod are proposed. The research results can provide certain technical support for the strength assessment of the vehicle steering rod. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Toward the Usage of Deep Learning Surrogate Models in Ground Vehicle Aerodynamics.
- Author
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Eiximeno, Benet, Miró, Arnau, Rodríguez, Ivette, and Lehmkuhl, Oriol
- Subjects
- *
DEEP learning , *LARGE eddy simulation models , *AERODYNAMICS , *INTERPOLATION spaces , *VEHICLE models , *REYNOLDS number - Abstract
This study introduces a deep learning surrogate model designed to predict the evolution of the mean pressure coefficient on the back face of a Windsor body across a range of yaw angles from 2. 5 ∘ to 10 ∘ . Utilizing a variational autoencoder (VAE), the model effectively compresses snapshots of back pressure taken at yaw angles of 2. 5 ∘ , 5 ∘ , and 10 ∘ into two latent vectors. These snapshots are derived from wall-modeled large eddy simulations (WMLESs) conducted at a Reynolds number of R e L = 2.9 × 10 6 . The frequencies that dominate the latent vectors correspond closely with those observed in both the drag's temporal evolution and the dynamic mode decomposition. The projection of the mean pressure coefficient to the latent space yields an increasing linear evolution of the two latent variables with the yaw angle. The mean pressure coefficient distribution at a yaw angle of 7. 5 ∘ is predicted with a mean error of e ¯ = 3.13 % when compared to the WMLESs results after obtaining the values of the latent space with linear interpolation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Characteristics of Vehicle Tire and Road Wear Particles' Size Distribution and Influencing Factors Examined via Laboratory Test.
- Author
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Zhong, Chongzhi, Sun, Jiaxing, Zhang, Jing, Liu, Zishu, Fang, Tiange, Liang, Xiaoyu, Yin, Jiawei, Peng, Jianfei, Wu, Lin, Zhang, Qijun, and Mao, Hongjun
- Subjects
- *
PARTICLE size distribution , *TIRES , *PARTICULATE matter , *VEHICLE models - Abstract
With the implementation of strict emission regulations and the use of cleaner fuels, there has been a considerable reduction in exhaust emissions. However, the relative contribution of tire wear particles (TWPs) to particulate matters is expected to gradually increase. This study conducted laboratory wear experiments on tires equipped on domestically popular vehicle models, testing the factors and particle size distribution of TWPs. The results showed that the content of tire wear particle emission was mainly ultrafine particles, accounting for 94.80% of particles ranging from 6 nm to 10 μm. There were at least two concentration peaks for each test condition and sample, at 10~13 nm and 23~41 nm, respectively. The mass of TWP emission was mainly composed of fine particles and coarse particles, with concentration peaks at 0.5 μm and 1.3–2.5 μm, respectively. Both the number and mass of TWPs exhibited a bimodal distribution, with significant differences in emission intensity among different tire samples. However, there was a good exponential relationship between PM10 mass emissions from tire wear and tire camber angle. The orthogonal experimental results showed that the slip angle showed the greatest impact on TWP emission, followed by speed and load, with the smallest impact from inclination angle. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Shared Autonomous Vehicle Modeling Considering System Optimization and Simulation.
- Author
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Kai Huang, Yantao Huang, and Kockelman, Kara M.
- Subjects
- *
MATHEMATICAL optimization , *VEHICLE models , *SIMULATION methods & models , *MOTOR vehicle driving , *PRICES - Abstract
This paper optimizes the assignment of shared automated vehicles under users' uncertain departure times. Automated vehicles can drive themselves, so no staff are needed to relocate vehicles in the one-way carsharing system. To optimize fleet placement and use, a twophase solution method was established. Phase 1 strategically distributes vehicles across stations using a system optimization approach, while Phase 2 tracks vehicle movements via an agent-based simulation model. Phase 1 solutions serve as inputs to Phase 2 simulations. Using a fleet size of roughly 10,000 vehicles, case study applications were run across the Austin, Texas region's six-county network. In the base case setting, results suggest that system profits are optimized when vehicle rental is priced at $1.28=km ($0.8=mi). The number of proactive vehicle relocations falls 9.8% if the relocation operation cost rises from $0.096=km ($0.06=mi) to $0.32=km ($0.2=mi). Average per-trip profit is $10.60 when using high-cost vehicles, and $11.60 when using low-cost vehicles. Results from a 3-h simulation show an average person-trip length of 25 km (15.6 mi), with 29.6 min of average driving time. When a 24-h day was simulated, the vehicle-occupied time and vehicle-distance traveled were 4 h and 200 km (125 mi) per vehicle-day, respectively. The low coefficient of variation of satisfied demand across 30 demand scenarios suggests the robustness of the two-phase solution method. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. In vitro diffusion of plant phenolics through the skin: A review update.
- Author
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Silva, Gisláine C., Rodrigues, Rodney A. F., and Bottoli, Carla B. G.
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PHENOLS , *TOPICAL drug administration , *PLANT extracts , *PLANT cells & tissues , *FREE radicals , *VEHICLE models - Abstract
Objective: Excessive skin exposure to deleterious environmental variables results in inflammation as well as molecular and cellular impairments that compromise its functionality, aesthetic qualities, and overall well‐being. The implementation of topical administration of antioxidants and other compounds as a method for preventing or reversing damage is a rational approach. Numerous phenolic compounds derived from plants have demonstrated capabilities such as scavenging free radicals and promoting tissue healing. However, the primary obstacle lies in effectively delivering these compounds to the specific place on the skin, and accurately forecasting their diffusion through the skin can assist in determining the most effective tactics. Hence, this article provides a comprehensive analysis of recent literature pertaining to the in vitro skin diffusion characteristics of plant phenolics. The aim is to gain a deeper understanding of their behaviour when present in various forms such as solutions, suspensions, and formulations. Method: The data on plant extracts and isolated plant phenolic compounds in vitro skin diffusion assays published over the last six years were compiled and discussed. Results: Even though the gold standard Franz diffusion cell is the most commonly used in the assessment of in vitro plant phenolic skin diffusion profiles, a plethora of skin models and assay conditions are reported for a variety of compounds and extracts in different vehicles. Conclusion: The presence of numerous models and vehicles poses a challenge in creating correlations among the existing data on plant phenolic compounds. However, it is possible to draw some general conclusions regarding molecular, vehicle, and skin characteristics based on the gathered information. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Electric Vehicle Architecture Design Based on Database.
- Author
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Suh, Kwonhee and Moon, Jinkyu
- Subjects
- *
ARCHITECTURAL design , *DATABASE design , *INTERNAL combustion engines , *ELECTRIC automobiles , *PHENOMENOLOGICAL theory (Physics) , *VEHICLE models , *ELECTRIC vehicles - Abstract
The purpose of this study is to extend the mileage by improving the efficiency of the electric vehicle (EV) driving and thermal management system (TMS). The powertrain system and the TMS must be considered simultaneously from the architecture stage as complementary systems to maintain the driving performance of the EV. This paper proposes an EV architectural design method and a multi-physical EV modeling technique. The main components of the EV are standardized differently from those of the internal combustion engine (ICE) vehicle, and the TMS is designed by thermal system configuration. Therefore, instead of the traditional continuous variable-based design methodology, optimal combination design based on the component database (DB) and the configuration plot presents the combinational design method. The performance of an EV varies depending on the performance of driving components and TMS, and weather. This paper presents a Modelica-based vehicle modeling technique to integrate multiple physical phenomena. Finally, we implemented an automated design using the optimal combination design method and the multi-physical integrated vehicle model design framework. The design of the C-segment EV was carried out to review the validity of the proposed method. 2880 laboratories were planned and designed using design variables with 10 levels of mixing. As a result of the design, we have confirmed that the mileage increases by 5% compared to the previous one in NEDC mode. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. Development of System Characteristic Optimization Method to Achieve Vehicle Target Performance.
- Author
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Lee, Jin Hee
- Subjects
- *
MATHEMATICAL optimization , *BENCHMARKING (Management) , *DEGREES of freedom , *VEHICLE models , *NEW product development - Abstract
The application of 'Target Cascading' in the product development process is well known to be effective in various industry fields, and it is a methodology that is already actively applied in various forms in the field of vehicle Ride & Handling (R&H) performance development. This paper proposes a model-based vehicle performance benchmarking methodology and a technology for setting system characteristics to achieve handling performance objectives as a means of utilization for this. Rather than introducing already well-known target deployment techniques, a process is proposed for practical use in the vehicle development phase through the development of interfaces between low degrees of freedom vehicle model and optimization software. The methodology presented in this study is expected to be available in a timely manner as a practical vehicle performance development tool. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. The Electrochemical Commercial Vehicle (ECCV) Platform.
- Author
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Johansson, Max, Contet, Arnaud, Erlandsson, Olof, Holmbom, Robin, Höckerdal, Erik, Jonsson, Oskar Lind, Jung, Daniel, and Eriksson, Lars
- Subjects
- *
COMMERCIAL vehicles , *ELECTRIC trucks , *ENERGY management , *INDUSTRIAL efficiency , *VEHICLE models , *TRANSPORTATION industry - Abstract
Several technological challenges delay the adoption of electrified powertrains in the heavy-duty transport sector. For fuel-cell hybrid electric trucks, key issues include slow cold start, reduced cooling power during high ambient temperatures, and uncertainties regarding durability. In addition, the engineers must handle the complexity of the system. In this article, a Matlab/Simulink library is introduced, which has been developed to aid engineers in the design and optimization of energy management systems and strategies of this complex system that consider mechanical, electrochemical, and thermal energy flows. The library is introduced through five example vehicle models, and through case studies that highlight the various kinds of analysis that can be performed using the provided models. All library code is open source, open for commercial use, and runs in Matlab/Simulink without any need for external libraries. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
33. Modeling and Subjective Evaluation Method of Driveability for Fuel Cell Vehicles.
- Author
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Zhan, Jun, Zhu, Huainan, Duan, Chunguang, Zhong, Zhao-Hui, Huang, Wei, Zhu, Baoli, and Xu, Guangjian
- Subjects
- *
FUEL cell vehicles , *ELECTRIC vehicle batteries , *FUEL cells , *EVALUATION methodology , *VIRTUAL prototypes , *AUTOMOBILE driving simulators , *ACCELERATION (Mechanics) , *VEHICLE models - Abstract
Aiming at the demand for subjective evaluation of driveability for fuel cell vehicles, the modeling and evaluation method of driveability for fuel cell vehicles were studied in this paper. Firstly, a real-time model of the fuel cell vehicle powertrain system was established, which included the fuel cell model, power battery model, DC/DC converter model and drive motor model. Secondly, it was integrated with the vehicle dynamics model to form a virtual prototype of a fuel cell vehicle. And a virtual subjective evaluation platform for fuel cell vehicles was built by combining the virtual prototype and high-fidelity driving simulator. Thirdly, a subjective evaluation method of driveability for fuel cell vehicles was proposed, which included the starting performance, acceleration performance, uniform speed performance and tip-in/tip-out performance. Finally, the paper used the platform and method mentioned above to conduct subjective evaluations of the fuel cell vehicles. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. Vibration modelling and testing of off-road vehicle incorporating coupled roll and pitch vibrations.
- Author
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Huang, Peng, Yao, Yanchun, Xiu, Weijia, Wu, Jida, Geng, Duanyang, Yang, Zihan, and Li, Yongsheng
- Subjects
- *
VIBRATION tests , *OFF-road vehicles , *TIME-domain analysis , *FREQUENCIES of oscillating systems , *COMPUTER simulation , *VEHICLE models , *MATHEMATICAL models - Abstract
To investigate the vibration characteristics of off-road vehicles resulting from external excitations, this study explores a vibration modelling approach that accounts for the coupling of roll and pitch. A low-frequency vibration test was conducted, and the results were analysed in both the time domain and frequency domains. The mathematical model of the tractor was validated, affirming the accuracy of the off-road vehicle modelling method. This study focuses on the Shandong Wuzheng Group Co., Ltd. Renoman 2104 ratio tractor prototype (1:18) as the research subject. A vibration mathematical model and simulation model were developed, taking into account the coupled vibrations in both roll and pitch directions. Key parameters of the tractor, including damping, stiffness, centroid, inertia, and road roughness, were acquired through experimental testing. Upon comparing the numerical simulation model results with the experimental data, the findings reveal a 6.2% error between the left front axle test data and the simulation, and a 6.1% error for the right front axle. The vertical vibration primary frequency in the test is 13.1Hz, while the numerical simulation model registers 11.8 Hz, resulting in a relative error of 10%. Notably, the numerical simulation model exhibits significant consistency with the experimental results. These outcomes serve as a valuable reference for the parameter design and vibration control of off-road vehicles. • A vibration modelling approach of off-road vehicles is proposed. • The coupling vibration of pitch and roll is considered. • The methodology for acquiring tractor dynamic parameters has been elucidated. • An analysis of both time domain and frequency domain results was conducted to validate the mathematical model of the tractor. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. A comprehensive RFD-FTC-DCA system for hypersonic vehicles with saturation constraints.
- Author
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Li, Bing-Qian, Du, Meng-Zhen, Zhang, Ling-Hao, and Zong, Mu-Zhou
- Subjects
- *
HYPERSONIC planes , *FAULT-tolerant control systems , *FALSE alarms , *ACTUATORS , *VEHICLE models - Abstract
A comprehensive RFD-FTC-DCA system is proposed for the hypersonic vehicle with saturation constraints to resist the control surface damage, actuator faults, disturbances and parameter perturbation. Firstly, the hypersonic vehicle fault model is established. Secondly, the robust fault detection (RFD) observer is designed to detect the control surface damage and actuator faults accurately under the influences of disturbances and parameter perturbation. Thirdly, the fault-tolerant control (FTC) law is designed to resist the control surface damage, actuator faults, disturbances and parameter perturbation simultaneously. Finally, a dynamic control allocation (DCA) algorithm is designed to reallocate the FTC law and limit the deflection angle and velocity within saturation constraint. The comparison simulation results are presented to demonstrate that the RFD observer can detect the faults accurately and reduce false alarm rates effectively, the FTC law can resist the control surface damage, actuator faults, disturbances and parameter perturbation simultaneously, and the tracing errors of attack angle, side-slip angle and roll angle are only $ \pm 0.7^\circ $ ± 0.7 ∘ , $ \pm 0.2^\circ $ ± 0.2 ∘ and $ \pm 1.5^\circ $ ± 1.5 ∘ , respectively, and the DCA algorithm can reallocate the FTC law and limit the deflection angle and velocity within saturation values. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
36. Models for ground vehicle control on nonplanar surfaces.
- Author
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Fork, Thomas, Tseng, H. Eric, and Borrelli, Francesco
- Subjects
- *
VEHICLE models , *PAVEMENTS , *RIGID bodies - Abstract
We present a general approach to model the motion of a rigid body ground vehicle on a smooth nonplanar road surface. We generalise planar control-oriented models while preserving standard model states, inputs and outputs. We derive our approach from first principles, apply it to existing vehicle modelling approaches and test it through real-world experiments. We demonstrate that our approach improves upon the prediction accuracy of planar models. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
37. A simulation approach to estimate the general motor car-following model constant term.
- Author
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Naser, Roaa Sabah and Hasson, Saad Talib
- Subjects
- *
INTELLIGENT transportation systems , *VEHICULAR ad hoc networks , *VEHICLE models , *PREDICTION models - Abstract
Vehicular ad-hoc networks (VANETs) are widely contributing to the development of intelligent transport systems (ITS). VANETs are seeking to connect vehicles together to build services that are mainly appropriate for a vehicular environment. They try to do so with/without relying on Roadside Units (RSU) to assist the process of network topology management. To test or suggest a developed real application, a suitable vehicle mobility model must be proposed to be implemented in the tested simulation experiments. General Motor (GM) mobility model provided a realistic description of vehicular mobility at both macroscopic and microscopic levels. In this paper, in this paper, the GM car following model is modified based on one real traffic dataset (highD). The used dataset considers real vehicle traffic data. It is used in estimating the GM model parameter values. A developed prediction GM model is utilized in predicting driver behavior and its effect on the traffic environment. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. Maneuverability and stability of an articulated bus for bus rapid transit system.
- Author
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Sakhno, Volodymyr, Kravchenko, Oleksandr, Poljakov, Viktor, Chovcha, Iryna, Dižo, Ján, and Blatnický, Miroslav
- Subjects
- *
BUS rapid transit , *ARTICULATED vehicles , *VEHICLE models , *AUTOMOBILE steering gear - Abstract
The mathematical model of an articulated bus with a system of turning a hook-and-loop section for a dynamic way of turning is developed. For the developed model, indicators of maneuverability and stability of the bus were appointed. The model is based on a model of a vehicle with a trailer. The input of the design parameters of the bus and the trailer, the transfer ratio of the control drive and the magnitude of the moment to the indicators of the maneuverability of the bus are analyzed. On the basis of the results, in the analysis of the rational values of the gear ratios, which ensure the proximity of the trajectories of the characteristic points of the bus and the trailer, the value of the gear ratio of 0.85 was selected, which ensures the minimum value of the steering wheels' moment. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Ride quality and handling characteristics of a vehicle with active anti-roll bar suspension.
- Author
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Canpolat, Berkan, Akalın, Özgen, and Yeşilyurt, Halil Yahya
- Subjects
- *
OFF-road vehicles , *MOTOR vehicle springs & suspension , *VEHICLE models - Abstract
Ride quality is one of the important properties of an off-road vehicle limiting the speed-made-good on rough terrain. Anti-roll bars are used to limit the sprung mass roll angle and generate under-steer characteristics, improving the stability of a vehicle. However, anti-roll bars may have a negative influence on ride quality, particularly on natural terrain with random roughness. In this study, a multi-body dynamics model of an off-road vehicle having an independent suspension is used to investigate the effects of front anti-roll bar stiffness on ride quality using synthetically generated roughness profiles. The simulated results revealed that while the anti-roll bar does not influence the ride quality on symmetric roughness profiles, significantly higher seat base accelerations are observed with stiffer anti-roll bars on asymmetric profiles, particularly in the lateral axis. Based on these results an active anti-roll bar control algorithm, operating in a co-simulation environment, is proposed to reduce the seat base accelerations while maintaining the desired handling characteristics. Handling characteristics of the vehicle are investigated using various transient tests such as double-lane-change and J-turn. It is found that the ride quality of an off-road vehicle traversing over a natural terrain can be significantly improved using active anti-roll control without compromising the cornering characteristics. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Coupled kinetic-continuum modeling of reentry vehicle plasma environment.
- Author
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Shevyrin, A. and Bondar, Ye.
- Subjects
- *
MONTE Carlo method , *TEMPERATURE distribution , *ELECTRON temperature , *VEHICLE models , *PLASMA sheaths , *AEROTHERMODYNAMICS - Abstract
A new kinetic-continuum technique of the direct Monte Carlo simulation coupled with solution of the electron energy equation was applied to modeling of the high-enthalpyionized rare fied flow about are entry capsule. The new technique predict selectron temperature distributions completely different from those obtained with widely used approximation Te=Tv (N2). The technique was validated against the results of the RAM-CII flight experiment. More accurate prediction of electron temperature can improve validity of the studies of communucation black out phenomena and aerothermodynamics of super orbital entry. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. Combined longitudinal and lateral dynamics regulation of autonomous vehicles via induced ℒ2$$ {\mathcal{L}}_2 $$‐gain linear parameter varying control strategies based on parameter‐dependent Lyapunov functions.
- Author
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Gagliardi, Gianfranco, D'Angelo, Vincenzo, and Casavola, Alessandro
- Subjects
- *
LYAPUNOV functions , *AUTONOMOUS vehicles , *MOTOR vehicle driving , *LINEAR matrix inequalities , *VEHICLE models , *MATHEMATICAL models - Abstract
This article considers a path tracking control problem for autonomous vehicles constrained to maintain a safe distance from the next vehicle in the lane. The control design problem is solved by considering a mathematical model of the vehicle that jointly describes the lateral and longitudinal dynamics. Specifically, the ℒ2$$ {\mathcal{L}}_2 $$ optimal controller is designed aimed at minimizing the orientation and position tracking errors with respect to a given reference path. Moreover, the controller is able to ensure that the vehicle can both follow a speed profile and automatically adjusts the vehicle speed to maintain a proper distance from the next vehicle. The lateral dynamic is regulated by a 2‐DOF feedforward/feedback controller, where the feedforward law is implemented by exploiting an inverse kinematic model of the vehicle. On the other side, the feedback action, along with the action of the controller in charge to regulate the longitudinal dynamics, is the ℒ2$$ {\mathcal{L}}_2 $$ optimal gain‐scheduling state‐feedback controller. In particular, a parameter‐dependent quadratic Lyapunov function approach is used to reduce the conservativeness of the solution and a suitable convex LMI optimization problem is formulated for the synthesis. The vehicle is described by a seven‐degrees‐of‐freedom (7DOF) full‐car model, with the tire‐generated forces described by the classical Pacejka's Magic Formula. In order to assess the performance of the proposed control strategy, simulations have been undertaken in Matlab/Simulink by considering an autonomous vehicle driving into an urban scenario. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
42. Vertical dynamics analysis and multi-objective optimization of electric vehicle considering the integrated powertrain system.
- Author
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Mo, Shuai, Chen, Keren, Zhang, Yingxin, and Zhang, Wei
- Subjects
- *
ELECTRIC vehicles , *OPTIMIZATION algorithms , *AUTOMOBILE chassis , *AUTOMOBILE power trains , *VEHICLE models , *NUMERICAL calculations , *DEGREES of freedom - Abstract
• A comprehensive vertical dynamics model of the electric vehicle considering the integrated powertrain system is proposed. • The limitations of traditional vertical dynamics model of electric vehicle in the high frequency range are revealed. • The effects of mounting stiffness and damping on the vibration of chassis and integrated powertrain system are explored. • A multi-objective optimization model is designed to minimize the vibration of chassis and integrated powertrain system. Integrated powertrain system, mainly composed of driving motor and reducer, is one of the excitation sources to electric vehicle vibration but is limited in coupling with the vertical vehicle dynamic in the existing research, which restricts the reliability of dynamics investigation of vehicle and integrated powertrain system. This work proposes a novel vertical dynamic model of the electric vehicle considering the integrated powertrain system, enabling the way to access the coupled vibration among the chassis, unsprung mass, and integrated powertrain system. The road irregularity, unbalanced magnetic pull, and gear mesh excitation are developed and are further applied to the novel vehicle dynamic model with ten degrees of freedom (DOFs). Then, the dynamic response between the novel model and traditional one is compared. Further, the effects of the stiffness and damping of suspension and mounting on the vibration of chassis and integrated powertrain system are explored by numerical calculation. Finally, a multi-objective optimization model is proposed and is driven by the dragonfly algorithm to minimize the vibration of chassis and integrated powertrain system. The research results shown that there will be present the new complex dynamic characteristics with considering the excitation from the integrated powertrain system. The suspension and mounting parameters have the nonlinear effects on the vehicle vibration. And the system vibration can be globally optimized with the optimization algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. Analysis of the influence of track irregularity on high-speed train ride comfort.
- Author
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Xiao, Xinbiao, Xu, HanWen, Yang, Yi, Chen, Peng, and Hu, Qin
- Subjects
- *
HIGH speed trains , *HUMAN body , *VEHICLE models - Abstract
The vibration of high-speed trains induced by track irregularities is a main factor affecting ride comfort. Especially, the long-wavelength track irregularities can reduce the passengers' ride comfort by increasing the vibration of the high-speed trains. A three-dimensional human body model coupled to a vehicle body and tracks is established to form a coupled human-seat-vehicle-track system for investigating the influence of the long-wavelength track irregularities on ride comfort. The parameters of the seated human model are determined by measurement based on the multi-island GA method. The coupled model is then used to evaluate the ride comfort of high-speed trains using ISO 2631 under the excitation of the track longitudinal level irregularities. The effects of primary, secondary suspension, and seat support vertical stiffness and damping on ride comfort are analysed. The results show that the track's longitudinal irregularities lead to high human body vibration levels and large ride comfort indices (lower ride comfort), especially when the irregularity excitation frequency is near the natural frequency of the high-speed train. The passengers' ride comfort is more sensitive to the vertical secondary suspension stiffness than the other suspension parameters. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. Clustering research of vehicle formation shaping based on energy consumption optimization.
- Author
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Wang, Y. Y., Wang, S. F., Zhang, J. Y., Long, S. Q., and Luo, M. Q.
- Subjects
- *
ENERGY consumption , *OPTIMIZATION algorithms , *TRAFFIC safety , *ACCELERATION (Mechanics) , *BIONICS , *VEHICLE models - Abstract
Multi-intelligent vehicles forming and maintaining a specific formation during traveling can save energy consumption and road resources, and improve traffic efficiency and driving safety. Centered around the Cooperative Vehicle Infrastructure(CVI) framework of the Internet of Vehicles(IOV), this paper delves into the control objectives of forming multi-intelligent vehicle formation, explores the theory of formation shaping process, and investigates the optimization of energy consumption in the formation shaping process. First, the clustering design is used to take the kinematic process of vehicles as an optimization process from the bionics, taking the instantaneous consumption indexes as the optimization objectives. Then, optimize the acceleration inputs of the vehicle formation process using the improved Artificial Fish Swarm Algorithm(AFSA), and iterate with the clustering algorithm part, so as to realize the formation shaping process with energy consumption as the optimization objective. Finally, ajoint simulation platform built by Simulation of Urban Mobility (SUMO) and Python is used for simulation verification, and the results show that the formation shaping process can be realized and achieve the optimal energy consumption under the scenarios proposed in this paper, thus verifying the validity of the clustering model of vehicle formation shaping and the energy consumption optimization algorithm designed in this paper. [ABSTRACT FROM AUTHOR]
- Published
- 2024
45. Driving Comfort Analysis Method of Highway Bridge Based on Human-Vehicle-Bridge Interaction.
- Author
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Guo, Zhi-Bo, Zou, Jian, Bu, Jian-Qing, and Zhang, Ji-Ren
- Subjects
- *
STEEL-concrete composites , *COMPOSITE construction , *FINITE element method , *BICYCLE trails , *VEHICLE models , *ELECTRIC bicycles , *ROADS - Abstract
Research on evaluating highway bridge performance through vehicle-bridge interaction (VBI) analysis has made significant advancements. However, when assessing driving comfort, using vehicle acceleration instead of human acceleration poses challenges in accurately representing comfort. First, the paper proposes a finite element analysis method for human-vehicle-bridge spatial interactions (HVBSIs). Then, the importance of wheel path roughness difference is explored when assessing driving comfort. Furthermore, a new method for evaluating driving comfort that includes human and vehicle vibration responses has been proposed, and a simulation example of the steel-concrete composite beam bridge (SCCBB) is used to verify the effectiveness of the proposed method. The results demonstrate that the HVBSI analysis method effectively simulates the interconnected vibrations of the human body, the spatial vehicle model, and the three-dimensional (3D) bridge model. Differences in wheel path roughness significantly impact the roll vehicle vibration responses, which are crucial in driving comfort analysis. The driver's body vibration response is essential for evaluating driving comfort, and its inclusion leads to increased comfort indices values. In comparison to traditional methods, the overall vibration total value (OVTV) increases by a maximum of 109.04%, and the level of weighted vibration ( L e q ) increases by a maximum of 6.74%. This leads to an upgrade from grade IV to grade V in terms of comfort level, indicating a reduced comfort. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
46. A Study on the Vehicle Antilock System Based on Adaptive Neural Network Sliding Mode Control.
- Author
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Li, Yaoping and Li, Han
- Subjects
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SLIDING mode control , *ANTILOCK brake systems in automobiles , *VEHICLE models , *BRAKE systems , *TORQUE control , *HYPERSONIC planes - Abstract
Vehicle antilock systems play a very important role in the stability and reliability during vehicle braking. Due to the complexity of the braking process, antilock braking system (ABS) usually face the problems such as nonlinearity, time-varying, and uncertain parameter modeling. Thus, aiming at the parameter model uncertainty problem of ABS, an adaptive neural network sliding mode controller (ADRBF-SMC) is designed in this paper. On this basis, establishing the quarter-vehicle model and the seven-degree-of-freedom vehicle model, and treating the difference between the two models as a kind of disturbance, carrying out vehicle braking performance simulation experiments to analyze the variation of braking performance parameters such as vehicle and wheel speeds, slip ratio, braking distance, braking torque, under the three cases of adaptive neural network sliding mode controller, traditional sliding mode controller, and no control. Simulation results show that the adaptive neural network sliding mode controller (ADRBF-SMC) proposed in this paper can play an effective control role in both vehicle dynamics models. In addition, the control method proposed in this paper has stronger anti-interference capability and higher robustness compared with the sliding mode controller (SMC). [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
47. Modeling car-following behavior during queue discharge at signalized intersections with countdown timer.
- Author
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Raveendran, Bijul, Mathew, Tom V., and Velaga, Nagendra R.
- Subjects
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SIGNALIZED intersections , *SPATIAL behavior , *SPATIAL variation , *VEHICLE models , *TRAFFIC violations , *ROAD interchanges & intersections - Abstract
Countdown timers impact driver behavior significantly and are widely used at signalized intersections in many countries. Literature shows potential vehicle class-specific temporal and spatial variations in driver behavior in the presence of timer. Therefore, first, this paper analyzed the temporal, spatial, and vehicle class-specific impacts of timer on driver behavior in heterogeneous traffic conditions based on variations in acceleration. Second, a Long Short-Term Memory model was developed to model vehicle discharge, incorporating the heterogeneity of traffic and impacts of timer. The performance of the model was compared with that of the Intelligent Driver Model using field trajectory data from three signalized intersections in Kerala, India. The model accurately predicts the following behavior with mixed spacing errors of 0.24 to 0.35 and an average mean squared error of spacing of 1.23. The results were better than, or comparable to, results from recent data-driven car-following models and significantly better than IDM. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. Cloud-Based Platoon Predictive Cruise Control Considering Fuel-Efficient and Platoon Stability.
- Author
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Zhou Wang, Duanfeng Chu, Bolin Gao, Liang Wang, Xiaobo Qu, and Keqiang Li
- Subjects
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CRUISE control , *MOTOR vehicle driving , *VEHICLE models , *PREDICTION models , *DATA modeling - Abstract
This work investigates commercial vehicle platoon predictive cruise control for highways. We propose a cloud-based platoon predictive cruise control method (CPPCC). A two-layered control architecture of the CPPCC is proposed as a platoon predictive cruise speed planning layer in the cloud and a platoon stabilization control layer. The CPPCC communication topology is proposed to achieve coupled control of the hierarchical architecture. The speed planning layer is a dynamic planning (DP) algorithm based on road slope in the rolling distance domain. The lower layer is a stability control algorithm to meet the stability requirements of vehicle platoon driving; the vehicle side is distributed model predictive control (DMPC). The CPPCC is validated by real road and vehicle data models, and comparative experiments with the traditional predecessor-leader following–cruise control (PLF-CC) platoon and predecessor following–cruise control (PF-CC) platoon. The speed error of the vehicle platoon was maintained at [−0.25, 0.30] (m=s) and the space error at [−0.13, 0.66] (m) in platoon stability. Against the comparison method, the CPPCC saved fuel by over 5.13% and achieved an overall operational efficiency improvement of 5.71%. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Modeling of Vehicle Left-Turn Trajectories and Exit Lane Selection at Signalized Intersections.
- Author
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Wuguang Lin, Guowei Yin, Hao Han, Yu Dong, Dilinazi Tayijiang, and Qifeng Yu
- Subjects
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SIGNALIZED intersections , *VEHICLE models , *TRAFFIC conflicts , *ROAD interchanges & intersections , *TRAFFIC safety , *MOTOR vehicle driving , *UTILITY theory - Abstract
Within the urban road system, traffic conflicts most frequently are concentrated at road intersections, and left-turning traffic is a prominent and pivotal factor leading to intersection conflicts. The scarcity of applied models that can comprehensively elucidate the shifting trajectory dynamics and exit lane selection behavior of left-turning vehicles has posed challenges to the accurate analysis and prediction of intersection vehicle conflict patterns. This study extracted trajectories of left-turning vehicles at intersections from video data. A vehicle left-turn trajectory model was formulated, hinging on changes in trajectory curvature. Moreover, leveraging geometric intersection parameters and video data, a vehicle exit lane selection model was devised using random utility theory. This model integrates variables such as intersection turning angle, vehicle type, entrance lane position, vehicle speed, following clearance, and the lead vehicle’s position in the exit lane. The outcomes indicate that left-turn trajectories can be approximated well with a flat curve, and the trajectory’s curvature has a quadratic parabolic correlation with the intersection’s aspect ratio. The trajectory model presented in this paper adeptly characterizes left-turning vehicle movement across diverse intersections. Similarly, the exit lane selection model adeptly forecasts the distribution of left-turning vehicles in exit lane positions. This predictive efficacy stems from the recognition that turning angle, entrance lane vehicle position, and vehicle speed profoundly impact the exit lane choice for left-turning vehicles. This research sheds light on the intricacies of driving behavior and exit lane selection of left-turning vehicles at signalized intersections. By focusing on these critical aspects, this study offers valuable insights that contribute to the improvement of intersection design and overall traffic safety. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. Traversable map construction and robust localization for unstructured road environments1.
- Author
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Lian, Jing, Chen, Shi, Li, Linhui, Sui, Duo, and Ren, Weiwei
- Subjects
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AUTONOMOUS vehicles , *POINT cloud , *MOTOR vehicle driving , *VEHICLE models , *ROADS - Abstract
Intelligent vehicles require accurate identification of traversable road areas and the ability to provide precise and real-time localization data in unstructured road environments. To address these issues, we propose a system for traversable map construction and robust localization in unstructured road environments based on a priori knowledge. The proposed method performs traversable area segmentation on the LiDAR point cloud and employs a submap strategy to jointly optimize multiple frames of data to obtain a reliable and accurate point cloud map of the traversable area, which is then rasterized and combined with the vehicle kinematic model for global path planning. Then, it integrates priori map information and real-time sensor information to provide confidence and priori constraints to ensure the robustness of localization, and it fuses multi-sensor heterogeneous data to improve real-time localization. Experiments are conducted in a mining environment to evaluate the performance of the proposed method on an unstructured road. The experimental results demonstrate that the traversable map and localization results based on the proposed method can meet the requirements for autonomous vehicle driving on unstructured roads and provide reliable priori foundation and localization information for autonomous vehicle navigation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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