Refine Your Search

Search Results

Technical Paper

Path Planning Algorithm of Intelligent Vehicle Based on Improved Visibility Graphs

2018-08-07
2018-01-1581
At present, the visibility graphs algorithm is mainly implemented in the field of mobile robot’s path planning on unstructured pavement. It only considers the common constraints such as travel time and move distance. The problems of road boundary and vehicle dynamics constraints are not involved. In this paper, a local path planning algorithm based on improved visibility graphs was proposed for intelligent vehicles traveling on structured road. The algorithm combined the geometric constraints of the road boundary with the vehicle dynamics constraints. By predicting the position of the obstacle vehicle in the preview time, the algorithm was used to generate the information of path network. Then, the performance index function was used to evaluate the trajectory which satisfying the maximum curvature constraint in the network. In this way a smooth path with minimum distances satisfying the constraints was obtained.
Technical Paper

Research on Variable Steering Ratio Control Strategy of Steer-by-wire Steering System

2018-08-07
2018-01-1583
Due to the elimination of the mechanical connection, the steer-by-wire steering system can freely design the angular transmission ratio between the hand steering wheel and the road steering wheel. In this paper, the variable steering ratio control strategies under normal driving conditions and unconventional driving conditions were proposed. The variable steering ratio control of normal driving conditions is based on the ideal yaw rate gain, taking into account the low-speed steering lightness and high-speed steering stability, and the steering ratio varies with the vehicle speed and the hand steering wheel angle, which ensures the vehicle steering sensitivity at low speed and the steering stability at high speed. The variable steering ratio control of the unconventional driving conditions is based on yaw rate dynamic feedback control, and the steering ratio varies with the vehicle movement status.
Technical Paper

A Novel Direct Yaw Moment Control System for Autonomous Vehicle

2018-08-07
2018-01-1594
Although autonomous driving technology has become an emerging research focus, safety is still the most crucial concern when autonomous vehicles leave research laboratory and enter public traffic. Direct yaw moment control (DYC), which differentially brakes the wheels to produce a yaw moment, is an important system to ensure the driving stability of vehicle under extreme conditions. The design of traditional DYC system must need to take into account driver’s intention and vehicle dynamics. However, for autonomous vehicle, no human is involved in driving process, and enforcing traditional DYC system may conflict with the demands of the desired path. Therefore, in this paper, a novel DYC system for autonomous vehicle is proposed using a hierarchical control architecture.
Technical Paper

Analysis of Vehicle Steering Stability of Nonlinear Four Wheel Steering Based on Sliding Mode Control

2018-08-07
2018-01-1593
Steering movement is the most basic movement of the vehicle, in the car driving process, the driver through the steering wheel has always been to control the direction of the car, in order to achieve their own driving intention. Four Wheel Steering (4WS) is an advanced vehicle control technique which can markedly improve vehicle steering characteristics. Compared with traditional front wheel steering vehicles,4WS vehicles can steer the front wheels and the rear wheels individually for cornering, according to the vehicle motion states such as the information of vehicle speed, yaw velocity and lateral acceleration. Therefore, 4WS can enhance the handling stability and improve the active safety for vehicles.
Technical Paper

Passenger car 25% overlapping rate collision accident study base on CIDAS

2018-08-07
2018-01-1595
With vehicle technologies development,vehicle safety is much better than before, many companies put research focus on harder accident scenarios. 25% overlapping rate collision is considered as one type of most dangerous collision,this paper study this type accidents base on China In-Depth Accident Study (CIDAS) database. this database include more than 4000 cases in China. We study the accident contents from impact characteristics, human injury, seat position, injury causing part,and dirver behaviours. the paper can help researcher to create scenarios to test the ADAS technology in China and promote ADAS system.
Technical Paper

Driver Risk Perception model under Critical Cut-in scenario

2018-08-07
2018-01-1626
In China Cut-in scenario is quite common on both highway and urban road with heavy traffic and usually has a certain risk. While, research on the driver’s risk perception of Cut-in scenario is few. When facing a cutting-in vehicle, driver tends to brake in most case. The timing and dynamic characteristic of driver’s brake maneuver is the direct indicator of driver’s subjective risk perception. The objective risk evaluation factors include TTC (Time to collision), THW (Time Headway), longitudinal relative distance and lateral relative distance et al.. This paper aim at building a model quantitatively revealing the relationship between drivers’ subjective risk perception and the objective risk evaluation factors. Data is from China-FOT database, which has a travel distance about 130 thousand miles. It is found that in Cut-in scenario, driver tends to brake when the cutting-in vehicle right crossing line, and this time point is defined as initial brake time t_IB.
Technical Paper

Personalized Eco-driving for Intelligent Electric Vehicles

2018-08-07
2018-01-1625
Minimum energy consumption with maximum comfort driving experience define the ideal human mobility. Recent technological advances in most Advanced Driver Assistance Systems (ADAS) on electric vehicles not only present a significant opportunity for automated eco-driving but also enhance the safety and comfort level. Understanding driving styles that make the systems more human-like or personalized for ADAS is the key to improve the system comfort. This research focuses on the personalized, green and adaptive cruise control for intelligent electric vehicle based on the optimization of regenerative braking and typical driving styles, also known to be MyEco-ACC. First, a driving style model is abstracted as a Hammerstein model and its key parameters vary with different driving styles. Secondly, the regenerative braking system characteristics for the electric vehicle equipped with 4-wheel hub motors are analyzed and braking force distribution strategy is designed.
Technical Paper

Research on the Radiated Immunity Test Methods of ADAS Functions in Intelligent Vehicles

2018-08-07
2018-01-1636
According to the ISO 11451-2, the immunity performance of passenger cars and commercial vehicle shall be validated to electrical disturbances from off-vehicle radiation sources. Typical vehicle electrical or electronic systems such as double flash, monitor, or audio and entertainments systems have been validated through a standardized immunity test process. As the development of ADAS (Automated Driver Assistance System) functions in the vehicle technology, the reliability and accuracy of these functions in the complex electromagnetic fields must be validated. Radar and Camera or Lidar sensor based functions of AEB (Automated Emerge Brake), ACC (Automated Cruise Control) or LDW (Lane Departure Warning) might be invalid, especially when these sensors were illuminated by electrical disturbances in the real word. This work presents a novel test methodology of whole-vehicle immunity to off-board electrical disturbances, considering the main ADAS functions.
Technical Paper

Critical Driving Scenarios Extraction Optimization Method Based on China-FOT Naturalistic Driving Study Database

2018-08-07
2018-01-1628
Due to the differences in traffic situations and traffic safety laws, standards for extraction of critical driving scenarios (CDSs) vary from different countries and areas around the world. To maintain the characteristic variables under the Chinese typical CDSs, this paper uses the three-layer detection method to extract and detect CDSs in the Natural Driving Data from China-FOT project which executing under the real traffic situation in China. The first layer of detection is mainly based on the feature distributions which deviate from normal driving situations. These distributions associated with speed and longitudinal acceleration/lateral acceleration/yaw rate also quantify the critical levels classification.
Technical Paper

Developmental driver model based on preview-follower theory

2018-08-07
2018-01-1629
Understanding human drivers and modeling their behavior are two major functions of driver model. Whatever role of the driver model has gone through the process from simplicity to comprehensive. This paper proposed a conception of driver preview eccentricity to develop the driver model based on preview-follower mainly for modeling their behavior. The developmental driver model is significant for long vehicle, particularly for multi-axle vehicle. Almost all drivers have the feeling that it's more difficult to control a long vehicle than a short one. However, the main reason for this phenomenon is the driver's preview eccentricity. When we control a vehicle to a target point or follow a trajectory, we are acquiescently expect the vehicle's centroid to reach the target point or follow the trajectory virtually. But it is often difficult for a driver to estimate the position of the centroid of a long vehicle, especially for a novice driver.
Technical Paper

Intelligent traffic control method for emergency vehicles prioritization based on DSRC transportation system

2018-08-07
2018-01-1644
Emergency Vehicles (EmVs) prioritization is critical to be studied in view of the effectiveness of emergency delivery. Based on DSRC(Dedicated Short Range Communication)system, adaptive traffic lights can be adopted as vehicle status and traffic lights information can be delivered to Road Side Unit (RSU). In other research work of manipulating traffic lights, only the EmVs are considered. Therefore there are still risks for non-EmVs vehicles due to insufficient time of braking. This paper provides an adaptive traffic light control method which takes into account of EmVs and non-EmVs on all the directions of lanes at the road section. In this control method, three operation modes of traffic light are proposed and the traffic light can be converted among three operation modes: normal mode, warning mode and priority mode.
Technical Paper

Velocity Trajectory Planning for Saving Energy of Intelligent 4WD Electric Vehicle Using Model Predictive Control

2018-08-07
2018-01-1584
Abstract—In order to reduce the fuel consumption of intelligent four-wheel drive vehicles(4WD),this paper presents a new method of online speed trajectory planning.It can realize online real-time control of vehicle speed,avoid high fuel consumption caused by rapid acceleration and rapid deceleration and also improve driving comfort which are particularly important for urban conditions.
Technical Paper

Abnormal Bus Data Analysis of Intelligent and Connected Vehicle Based On Neural

2018-08-07
2018-01-1640
In the paper, our research of abnormal bus data analysis of intelligent and connected vehicle aims to detect the abnormal data rapidly and accurately generated by the hackers who send malicious commands to attack the intelligent and connected vehicles through three patterns, including remote non-contact, short-range non-contact and contact. Because the vehicle bus is the final connector to the electronic control unit (ECU), we can monitor all threats through detecting the abnormal data on bus. Based on that, drivers or vehicles can respond to the cybersecurity problems in time, adopt corresponding security mechanism and avoid serious losses.
Technical Paper

A Localization System for Autonomous Driving: Global and Local Location Matching based on Mono-SLAM

2018-08-07
2018-01-1610
The utilization of the SLAM (Simultaneous Localization and Mapping) technique was extended from the robotics to the autonomous vehicles for achieving the positioning. However, SLAM cannot obtain the global position of the vehicle but a relative one to the start. For sake of this, a fast and accurate system was proposed to obtain both the local position and the global position of vehicles based on mono-SLAM which realized the SLAM by using monocular camera with a lower cost and power consumption. Firstly, the rough latitude and longitude of current position was obtained by using common GPS without differential signal. Then, the Mono-SLAM operated on the consecutive video frames to generate the localization and local trajectory map and its accuracy was further improved by utilizing the IMU information. After that, a piece of Map centered in the rough position obtained by common GPS was downloaded from the Open Street Map.
Technical Paper

Analysis of Human Machine Interaction Program in Lane keeping Assist System based on Field Test

2018-08-07
2018-01-1632
Lane keeping assist system (LKA) alerts the driver or intervenes in the driving when the vehicle deviates from the lane. But its effect is highly dependent on the driver's acceptance. Distance to Lane Crossing (DTLC) and Time to Lane Crossing (TTLC) are two important factors to consider the danger level of the scenario, which are also two references for drivers to make decisions. At present, most of the functional design standards are based on these values, while they often differ for different vehicle movements. This study uses a driving robot to precisely control the test conditions and performs field tests on two advanced autonomous vehicles in National Intelligent Connected Vehicle (Shanghai) Pilot Zone. The test conditions are extended based on various test standards and the LKA performance of vehicles in the pre-experiment.
Technical Paper

Study on Important Indices Related to Driver Feelings for LKA Intervention Process

2018-08-07
2018-01-1586
KEYWORDS: driver feelings, Characteristic Indices, correlation model, Random Forests algorithm ABSTRACT Lane Keeping Assistance (LKA) system is a very important part in Advanced Driver Assistance Systems (ADAS). It prevents vehicle from departing out of the lane by exerting intervention. But inappropriate performance during LKA intervention makes driver feel uncomfortable. The intervention of LKA can be divided into 3 parts: intervention timing, intervention process and intervention ending. Many researches have studied about intervention timing and ending, but factors such as yaw rate and steering wheel velocity during intervention process also affect driver feelings a lot. To increase driver acceptance of LKA, objective and subjective tests were designed and conducted to explore important indices which are highly correlated with driver feelings. Different kinds of LKA controller control intervention process in different ways.
Technical Paper

Robust Multi-Target Tracking Algorithm Based on Automotive Millimeter-Wave Radar

2018-08-07
2018-01-1601
Automotive radar can be used to detect pedestrians and vehicles and keep stable tracking of the targets. Multi-targets tracking is the key techniques when tracking in the complicated road condition. Some targets may lose alarm and there may be some false targets among the measurement because the radar would be affected seriously in the complicated road condition especially by the clutter and multi-path effect. Tracking can solve the effect of the false targets to a certain extent and provide a stable and accurate state of the targets. How to associate the track and the measurement is important in multi-targets tracking system. A robust tracking algorithm using joint integrated probabilistic data association is proposed. Unlike the nearest neighbor method, all the possible combinations of track measurement assignments are considered and the probabilities of the joint events are calculated.
Technical Paper

Millimeter-wave Automotive Radar Target Detection Algorithm Based on Spatial Compressive Sensing

2018-08-07
2018-01-1621
Millimeter wave automotive radar is one of the most important sensors in the advanced driver assistance system(ADAS) and autonomous driving system,which detects the target vehicles around the ego vehicle via processing transmitted and echo signals. However, the classical radar signal processing methods’ sampling frequency is very high, because the Shannon Nyquist sampling theorem which requires the sampling frequency of IF signal must be greater than the double of IF signal frequency is used to determine the sampling frequency of the IF signal. Besides, for the classical radar signal processing methods, the resolution of range, velocity and azimuth can’t meet the requirement of highly automated driving, especially azimuth. In order to solve these problems, a new novel MIMO(multiple-input multiple-output) radar target detection algorithm based on compressive sensing in the spatial domain is proposed in this paper.
Technical Paper

Lane Detection System for Night Scenes

2018-08-07
2018-01-1617
Most of algorithms of lane detection mainly aim at the scene of daytime. However, the camera is very sensitive to the light which causes such algorithms are unstable for the lane detection at night. This paper proposed a lane detection algorithm that largely improves the lane detection’s performance when it used at night. Step one is image processing. According to the feature of lane’s color, we focus on the image’s white and yellow parts and transform the original image to grayscale image. When the image’s value of grayscale is relatively small, an image enhancement method will be used to improve the contrast between lane line and road. Then, extracting a region of interesting from image (ROI) according the fixed location of camera mounted inside the car. In ROI, we used a creative algorithm named Correlation filter to remove image noise and remain the feature of lane. In step one, the filter matrix looks like “[0 1 1;-1 0 1;-1 -1 0]”.
Technical Paper

Trajectory-tracking Control for Autonomous Driving Considering its Stability with ESP

2018-08-07
2018-01-1639
With rapid increase of vehicles on the road, safety concerns have become increasingly prominent. Since the leading cause of many traffic accidents is known to be by human drivers, developing autonomous vehicles is considered to be an effective approach to solve the problems above. Although trajectory tracking plays one of the most important roles on autonomous driving, handling the coupling between trajectory-tracking control and ESP under certain driving scenarios remains to be challenging. This paper focuses on trajectory-tracking control considering the role of ESP. A vehicle model is developed with two degrees of freedom, including vehicle lateral, and yaw motions .Based on the proposed model, the vehicle trajectory is separated into both longitudinal and lateral motion. The coupling effect of the vehicle and ESP is analyzed in the paper. The lateral trajectory-tracking algorithm is developed based on the preview follower theory.
X