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Vehicle Interior Sound Quality Dynamic Objective Evaluation Inidex Analysis

Jilin University-Xiaolin Cao, Jiankun Yuan, Si Sun, Jing Chen
Jilin University Automotive Engrg Colleg-Dengfeng Wang
  • Technical Paper
  • 2020-01-1544
To be published on 2020-06-03 by SAE International in United States
The studies pertaining to vehicle interior sound quality have been gaining popularity in the last couple of decades. The vehicle subjective assessment and objective measurement are two hot research spots of this research field. For the objective evaluation, the traditional indexes that most researches used were based on a short time stationary assumption. However, when the vehicle is running, the interior sound environment is a dynamic processing. It is inconsistent with the assumption obviously. In this paper, the standard deviation and the range of several traditional psychoacoustic indexes were introduced as dynamic objective evaluation indexes to reflect the volatility and fluctuation range of these indexes. In order to evaluate the effectiveness of these dynamic objective evaluation indexes, some subjective evaluation indexes were chosen as reference parameters. Then we compared the importance degrees between the proposed dynamic objective indexes and some traditional objective evaluation indexes to the reference parameters based on the rough set theory. After the analysis, ranks of importance degree were obtained. The results are helpful to find suitable dynamic objective indexes as necessary…
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Trajectory Planning and Tracking for Four-Wheel-Steering Autonomous Vehicle with V2V Communication

Jilin University-Fangwu Ma, Yucheng Shen, Jiahong Nie, Xiyu Li, Yu Yang, Jiawei Wang, Guanpu Wu
  • Technical Paper
  • 2020-01-0114
To be published on 2020-04-14 by SAE International in United States
Lane-changing is a typical traffic scene effecting on road traffic with high request for reliability, robustness and driving comfort to improve the road safety and transportation efficiency. The development of connected autonomous vehicles with V2V communication provide more advanced control strategies to research of lane-changing. Meanwhile, four-wheel steering is an effective way to improve flexibility of vehicle. The front and rear wheels rotate in opposite direction to reduce the turning radius to improve the servo agility operation at the low speed while those rotate in same direction to reduce the probability of the slip accident to improve the stability at the high speed. Hence, this paper established Four-Wheel-Steering(4WS) vehicle dynamic model and quasi real lane-changing scenes to analyze the motion constraints of the vehicles. Then, the polynomial function was used for the lane-changing trajectory planning and the extended rectangular vehicle model was established to get vehicle collision avoidance condition. Vehicle comfort requirements and lane-changing efficiency were used as the optimization variables of optimization function and the control of trajectory tracking can be obtained by using…
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Further Study of the Vehicle Rattle Noise with Consideration of the Impact Rates and Loudness

Jilin University-Shuming Chen
SKL of Vehicle NVH and Safety Technology-Linyuan Liang, Peiran Li
  • Technical Paper
  • 2020-01-1261
To be published on 2020-04-14 by SAE International in United States
With the prevalent trend of the pure electric vehicle, vehicle interior noise has been reduced significantly. However, other noises become prominent in the cabin. Especially, the BSR noise generated by friction between parts and the clearance between components become the elements of complaints directly affect the quality of vehicles. Currently, the BSR noises are subjectively evaluated by experts, and the noise samples are simply labeled as ‘qualified’ or ‘unqualified’. Therefore, it is necessary to develop an evaluation model to assess the BSR noise objectively. In this paper, we study the vehicle rattle noise intensively. Several types of rattle noise were recorded in a semi-anechoic room. The recorded signals were then processed in the LMS test lab. to extract the single impact segments. A pool of simulated signals with different impact rates (number of impacts per second) and various loudness was synthesized for analyzation. To verify the universality of the assessment, the in-vehicle background noises were also recorded. The in-vehicle background noises were added to the rattle noise samples to simulate the in-vehicle test environment. Sound…
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Simulation of Curved Road Collision Prevention Warning System of Automobile Based on V2X

Jilin University-Xuanhe Li, Jian Wu, Rui He, Bing Zhu, Jian Zhao, Hang Zhou
  • Technical Paper
  • 2020-01-0707
To be published on 2020-04-14 by SAE International in United States
The high popularity of automobiles has led to frequent collisions. According to the latest statistics of the United Nations, about 1.25 million people worldwide die from road traffic accidents each year. In order to improve the safety of vehicles in driving, the active safety system has become a research hotspot of various car companies and research institutions around the world. Among them, the more mature and popular active security system are Forward Collision Warning(FCW) and Autonomous Emergency Braking(AEB). However, the current active safety system is based on traditional sensors such as radar and camera. Therefore, the system itself has many limitations due to the shortage of traditional sensors. Compared to traditional sensors, Vehicle to Everything (V2X) technology has the advantages of richer vehicle parameter information, no perceived blind spots, dynamic prediction of dangerous vehicle status, and no occlusion restriction. In order to overcome the many shortcomings of the existing anti-collision warning system and strategy, this paper proposes a curved road collision prevention warning strategy based on V2X technology. Through V2X technology, the state information released…
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Pressure Tracking Control of Electro-Mechanical Brake Booster System

Jilin University-Weihong Yang, Jian Wu, Rui He, Bing Zhu, Jian Zhao, Zhicheng Chen
  • Technical Paper
  • 2020-01-0211
To be published on 2020-04-14 by SAE International in United States
The Electro-Mechanical Brake Booster system (EMBB) is a kind of novel braking booster system, which integrates active braking, regenerative braking, and other functions. It usually composes of a servo motor and the transmission mechanism. EMBB can greatly meet the development needs of vehicle intelligentization and electrification. During active braking, EMBB is required to respond quickly to the braking request and track the target pressure accurately. However, due to the highly nonlinearity of the hydraulic system and EMBB, traditional control algorithms especially for PID algorithm do not work well for pressure control. And a large amount of calibration work is required when applying PID algorithms to pressure control in engineering. In this paper, a fuzzy adaptive PI pressure control algorithm based on feed-forward is proposed to a novel self-designed EMBB mechanism, which is utilized to overcome the nonlinear pressure control problem when EMBB is in active braking and improve the control effect of PID algorithm. First, the structure of the EMBB system used in the paper and its working principle is presented. Second, this paper designs…
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A Path Planning and Model Predictive Control for Automatic Parking System

Jilin University-Xiangxi Meng, Jian Wu, Rui He, Bing Zhu, Jian Zhao
  • Technical Paper
  • 2020-01-0121
To be published on 2020-04-14 by SAE International in United States
With the increasing number of urban cars, parking has become the primary problem that people face in daily life. Therefore, many scholars have studied the automatic parking system. In the existing research, most of the path planning methods use the combined path of arc and straight line. In this method, the path curvature is not continuous, which indirectly leads to the low accuracy of path tracking. The parking path designed using the fifth-order polynomial is continuous, but its curvature is too large to meet the steering constraints in some cases. In this paper, a continuous-curvature parking path is proposed. The parking path tracker based on Model Predictive Control (MPC) algorithm is designed under the constraints of the control accuracy and vehicle steering. Firstly, in order to make the curvature of the parking path continuous, this paper superimposes the fifth-order polynomial with the sigmoid function, and the curve obtained has the continuous and relatively small curvature. Therefore, the superposition curve is used as a parallel parking path while the superposition curve and its inverse function curve…
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Cooperative Estimation of Road Grade Based on Multidata Fusion for Vehicle Platoon with Optimal Energy Consumption

Jilin University-Fangwu Ma, Yu Yang, Jiawei Wang, Yang Zhao, Yucheng Shen, Guanpu Wu
The Ohio State University-Bilin Aksun Guvenc, Levent Guvenc
  • Technical Paper
  • 2020-01-0586
To be published on 2020-04-14 by SAE International in United States
The platooning of automated vehicles possesses the significant potential of reducing energy consumption in the Intelligent Transportation System (ITS). Moreover, with the rapid development of eco-driving technology, vehicle platoon can further enhance the fuel efficiency by optimizing the efficiency of the powertrain. Since road grade takes great account effectting energy consumption of vehicle, the estimation of the road grade with high accuracy is the key factor for connected vehicle platoon to optimize energy consumption using vehicle-to-vehicle (V2V) communication. Commonly the road grade is quantified by single consumer grade global positioning system (GPS) with the geodetic height data which is rough in meter-level, increasing the difficulty to precisely estimate the road grade. This paper presents a novel cooperative estimation method Extended Kalman Filter (EKF) to obtain the accurate information of slopes by multidata fusion of GPS, Inertial Measurement Unit (IMU) using vehicle platoon communication, i.e. the following vehicle fuses the data which was measured by the on-board sensors and delivered by the proceding vehicle. Considering the accurate road grade information, the fuel consumption optimazition of the…
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A Prediction Method of Tire Combined Slip Characteristics from Pure Slip Test Data

Jilin University-Danhua Xia, Dang Lu
Zhongce Rubber Group Co., Ltd.-Yang Tong
  • Technical Paper
  • 2020-01-0896
To be published on 2020-04-14 by SAE International in United States
A high-precision steady state tire model is critical in the tire and vehicle matching research. For the moment, the popular Magic Formula model is an empirical model, which requires the pure and combined test data to identify the model parameters. Although MTS Flat-trac is an efficient tire test rig, the long test period and high test cost of a complete tire model tests for handling are yet to be solved. Therefore, it is necessary to explore a high accuracy method for predicting tire complex mechanical properties with as few test data as possible. In this study, a method for predicting tire combined slip characteristics from pure cornering and pure longitudinal test data has been investigated, and verified by comparing with the test data. Firstly, the prediction theory of UniTire model is introduced, and the formula for predicting combined slip characteristics based on constant friction coefficient is derived. Secondly, three different sizes of tires were tested for force and moment, and then the combined slip characteristics were predicted through the proposed method, and the prediction accuracy…
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Research on Control Strategy Optimization for Shifting Process of Pure Electric Vehicle Based on Multi-Objective Genetic Algorithm

Jilin University-Yulong Lei, Jingxu Zhang, Yao Fu, Fuchun Jia, Binyu Wang
  • Technical Paper
  • 2020-01-0971
To be published on 2020-04-14 by SAE International in United States
With more and more countries proposing timetables for stopping selling of fuel vehicles, China has also issued a “dual-slope” policy. As electric vehicles are the most promising new energy vehicle, which is worth researching. The integration and control of the motor and gearbox have gradually become a hot research topic due to low cost with better performance.This paper takes an electric vehicle equipped with permanent magnet synchronous motor and two-gear automatic transmission without synchronizer and clutch as the research object. Through the action of the motor, gearbox and shift actuator in the shifting process, the whole vehicle dynamics is modeled in each stage of shifting, a method for determining a short-term driving style intensity factor for decision shifting is proposed, three evaluation indexes of the shift quality of electric vehicle are put forward, the control parameters affecting the shift quality are analyzed, and the mathematical relationship between the shift control parameters, the shifting time and the shifting impact are obtain. Besides, the NSGA-II algorithm is used to carry out multi-objective global optimization of the whole…
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Intention-aware Lane Changing Assistance Strategy Basing on Traffic Situation Assessment

Jilin University-Jian Wu, Sihan Liu, Rui He, Bohua Sun
  • Technical Paper
  • 2020-01-0127
To be published on 2020-04-14 by SAE International in United States
Traffic accidents avoidance is one of the main advantages for automated vehicles. As one of the main causes of vehicle collision accidents, lane changing of the ego vehicle in case that the obstacle vehicles appear in the blind spot with uncertain motion intentions is one of the main goals for the automated vehicle. An intention-aware lane changing collision assistance strategy basing on traffic situation assessment in the complex traffic scenarios is proposed in this paper. Typical Regions of Interest (ROI) within the detection range of the blind spots are selected basing on the road topology structures and state space consisting of the ego vehicle and the obstacle vehicles. Then the motion intentions of the obstacle vehicles in ROI are identified basing on Gaussian Mixture Models (GMM) and the corresponding motion trajectories are predicted basing on the state equation. Traffic situation is assessed according to the index of the motion intentions and the coupling tendency between the ego vehicle and the obstacle vehicles and the risk level is graded basing on the map with collision time.…