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Optimal Design of Carbon Fiber B-Pillar Structure Based on Equal Stiffness Replacement

SAE International Journal of Transportation Safety

China-Qihua Ma
Donghua University, China-Xuehui Gan
  • Journal Article
  • 09-08-01-0003
Published 2020-03-23 by SAE International in United States
Based on the characteristics of high strength and modulus of carbon fiber-reinforced composite (CFRP), in this article, the CFRP material was used to replace the steel material of the automobile’s B-pillar inner and outer plates, and the three-stage optimization design of the lamination structure was carried out. Firstly, this article used the principle of equal stiffness replacement to determine the thickness of the carbon fiber B-pillar inner and outer plates, and the structural design of the replaced B-pillar was also carried out. Secondly, on the basis of the vehicle collision model, the B-pillar subsystem model was extracted, and the material replacement and collision simulation were carried out. Thirdly, the free-size optimization, size optimization, and lamination sequence optimization of the CFRP B-pillar were performed to get the best ply structure; the objective of optimization was to minimize the carbon fiber B-pillar inner and outer plates mass, and the constraint conditions of optimization were the intrusion amount and intrusion speed of the B-pillar loading points. Finally, the optimization results of carbon fiber B-pillar were verified by simulation.…
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Defect Detection of Railway Fasteners Based on Improved PHOG Characteristics

SAE International Journal of Transportation Safety

China-Jiaming Hu
Northeast Electric Power University, China-Chun-Ming Wu
  • Journal Article
  • 09-08-01-0002
Published 2020-03-23 by SAE International in United States
Aiming at the problem of low recognition rate and slow speed caused by the small proportion of key area information in feature vectors of original Pyramid Histogram of Gradients (PHOG) features, an improved feature extraction method of PHOG is proposed. The PHOG feature extraction method is combined with edge feature enhancement method based on Census transform to extract feature vectors of fasteners, and dimensionality reduction is processed by Kernel Principal Component Analysis (KPCA) method to reduce the interference of redundant information. The vector is inputted into the support vector machine for training in order to get the classifier model and realize the automatic identification of the fastener’s state. The simulation results show that compared with the traditional PHOG method, this feature extraction method improves the false detection rate by 2.7%, and the complexity of the algorithm is greatly reduced.
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Influence Analysis of AEB Two-Wheeler on Passenger Car Impact Two-Wheeler Traffic Accidents in China

China-Li Xudong
China Automotive Technology and Research Center-Lian Xiaowei, Wang Xingchang
  • Technical Paper
  • 2020-01-5023
Published 2020-02-24 by SAE International in United States
AEB two-wheeler system is an active safety technology which developed for avoiding two-wheeler accidents. With a large number of two wheelers, China needs to conduct research and analysis of this system. In this paper, real traffic accident data in China are used to analyze the possible influence of AEB two-wheeler system on traffic accidents. The paper chooses real passenger car impact two wheeler accidents happen in China, and gets the characteristics of data analysis. Then the paper analysis the influence of AEB system using position data when TTC=3s. According to the analysis, the detection range of 90 meters and the detection angle of 45 degrees can improve the recognition rate of day crossing accident by 17.7%, night crossing accident by 21.5% and longitudinal accident by 38.8%. The paper provides effective support for the development and test of AEB two-wheeler system in China.Car-to-two-wheeler accidentAEB two-wheeler systemInfluence of the accident
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Model Predictive Automatic Lane Change Control for Intelligent Vehicles

China-Wu Guangqiang
School of Automotive Engineering, Tongji University, China-Ren Meng, Chen Xunjie, Liu Xuyang
  • Technical Paper
  • 2020-01-5025
Published 2020-02-24 by SAE International in United States
As a basic link of driving behavior in urban roads, vehicle lane changing has a significant impact on traffic flow characteristics and traffic safety, and the automation of lane change is also a key issue to be solved in the field of intelligent driving. In this paper, the research on the automatic lane change control for intelligent vehicles is carried out. The main work is to build the overall structure of the vehicle's automatic lane change behavior, of which the planning and tracking are focused. The strategy of Constant Time Headway (CTH) is used in the lane change decision. The lane change trajectory adopts the model of constant velocity offset plus sine function, and the longitudinal displacement is determined by the vehicle speed when changing lanes. Model Predictive Control (MPC) theory is used to track the trajectory, which optimizes tracking accuracy and vehicle stability and constrains the range and rate of change of vehicle speed and steering angle. By using weighted quadratic cost function, linearity matrix inequality constraints and upper and lower bound constraints, the…
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Research on Forward Collision Warning System and Fuzzy Control of Automatic Emergency Braking System

China-Shi Qin
Hefei University of Technology-Zhang Lei
  • Technical Paper
  • 2020-01-5033
Published 2020-02-24 by SAE International in United States
The automatic emergency braking (AEB) system and forward collision warning (FCW) system are significant for active safety systems. It can efficiently reduce the rear-end accidents and protect the drivers and pedestrians. The model of an E-class SUV is established with CarSim software, and the control strategy based on fuzzy control is developed with MATLAB/Simulink. Simulation analysis on several typical braking conditions is carded out. The experiment results agree with the analysis results, which indicates that the research method can satisfy the safety requirements of automatic emergency braking system and the accuracy requirement of forward collision warning system.
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Event-Triggered Robust Control of an Integrated Motor-Gearbox Powertrain System for a Connected Vehicle under CAN and DOS-Induced Delays

China-Li Xiang
Beihang University-Xu Xiangyang, Zhang Hui
  • Technical Paper
  • 2020-01-5016
Published 2020-02-24 by SAE International in United States
This paper deals with an integrated motor-transmission (IMT) speed tracking control of the connected vehicle when there are controller area network (CAN)-induced delays and denial of service (DOS)-induced delays. A connected vehicle equipped with an IMT system may be attacked through the external network. Therefore, there are two delays on the CAN of the connected vehicle, which are CAN-induced and cyber-attack delays. A DOS attack generates huge delays in CAN and even makes the control system invalid. To address this problem, a robust dynamic output-feedback controller of the IMT speed tracking system considering event-triggered detectors resisting CAN-induced delays and DOS-induced delays is designed. The event-triggered detector is used to reduce the CAN-induced network congestion with appropriate event trigger conditions on the controller input and output channels. CAN-induced delays and DOS-induced delays are modeled by polytopic inclusions using the Taylor series expansion. Then, an IMT speed tracking system that considers two delays and takes into account the switching stability of the event-triggered detector, a dynamic output-feedback controller that satisfies the energy-to-peak performance is established. The dynamic…
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Cooperative Ramp Merging Control for Connected and Automated Vehicles

China-Xu Biao
School of Vehicle and Mobility, Tsinghua University, China-Meng Tianchuang
  • Technical Paper
  • 2020-01-5020
Published 2020-02-24 by SAE International in United States
Traffic congestions are increasingly severe in urban areas, especially at the merging areas of the ramps and the arterial roads. Because of the complex conflict relationship of the vehicles in ramps and arterial roads in terms of time-spatial constraints, it is challenging to coordinate the motion of these vehicles, which may easily cause congestions at the merging areas. The connected and automated vehicles (CAVs) provides potential opportunities to solve this problem. A centralized merging control method for CAVs is proposed in this paper, which can organize the traffic movements in merging areas efficiently and safely. In this method, the merging control model is built to formulate the vehicle coordination problem in merging areas, which is then transformed to the discrete nonlinear optimization form. A simulation model is built to verify the proposed method. The simulation results show that the proposed method has significant potential to improve vehicle fuel economy in merging scenarios.
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Parameter Estimation of Non-Paved Roads for ICVs Using 3D Point Clouds

China-Xie Guotao
State Key Laboratory of Advanced Design and Manufacturing fo-Yan Kangjian, Hu Manjiang, Wang Dongsheng, Wang Xiaowei
  • Technical Paper
  • 2020-01-5021
Published 2020-02-24 by SAE International in United States
Road parameter estimation is important for intelligent and connected vehicles (ICVs) operating on non-paved roads as it may influence their path planning and motion control. This paper presents a method for the estimation of longitudinal slopes, lateral slopes, and roughness of non-paved roads using 3D point clouds. Firstly, the regions of interest (ROIs) of ground are extracted by rasterizing the point clouds with grids, and divided into blocks according to the densities of point clouds. Next, longitudinal and lateral slopes are estimated by calculating the angles between two preference planes fitted using Random Sample Consensus (RANSAC) and Least Squares. Finally, an index of roughness, which is similar to International Roughness Index (IRI), is proposed for road roughness estimation in different grids. Experimental tests on non-paved roads demonstrate that the proposed algorithm has satisfactory performance in terms of the estimation accuracy of road slopes and roughness.
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Research on the Control Strategy of Trailer Tracking Tractor for Articulated Heavy Vehicles

China-Hongyu Zheng
Jilin University-Kaiqiang Pan, Jianjun Wu
Published 2019-11-04 by SAE International in United States
The purpose of this paper is to improve the path-following capability and high-speed lateral stability of the articulated heavy vehicles (AHVs). The six-axle heavy articulated vehicle was taken as the research object, in order to simplify the control design, the three-axle trailer of the articulated vehicles was simplified to a single-axle trailer. The Newton's second law was applied to the tractor unit and the single-axle trailer unit respectively, a three-degree-of-freedom vehicle yaw plane model was established, and its state space equation was derived. The trailer steering controller was designed by linear quadratic regulator (LQR) technique. At the same time, the optimal index function was determined by combining the vehicle state variables, and the optimal control input was obtained by using the algebraic Riccati equation. In order to achieve better control of the trailer unit, the relationship of the Ackerman steering geometry is used to obtain the ideal angle of each tire of the trailer unit. Co-simulation of low-speed steady circular motion and double lane change motion in Matlab/Simulink and Trucksim was carried out to verify…
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Braking Control Strategy Based on Electronically Controlled Braking System and Intelligent Network Technology

China-Hongyu Zheng
Jilin University-Rui Li
Published 2019-11-04 by SAE International in United States
In order to solve the coupling problems between braking safety, economical efficiency of braking and the comfort of drivers, a braking control strategy based on Electronically Controlled Braking System (EBS) and intelligent network technology under non-emergency braking conditions is proposed. The controller utilizes the intelligent network technology’s characteristics of the workshop communication to obtain the driving environment information of the current vehicle firstly, and then calculate the optimal braking deceleration of the vehicle based on optimal control method. The strategy will distribute the braking force according to the ideal braking force distribution condition based on the EBS according to the braking deceleration; the braking force will be converted to braking pressure according to brake characteristics. Computer co-simulations of the proposed strategy are performed, the strategy is verified under different initial speeds. The results show that the strategy enables the vehicle to stop within a safe distance, keeps the brake deceleration as smooth as possible for better braking comfort while at the same time obtaining better braking economy by increasing braking efficiency under different initial speeds.
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