Imperfect in-vehicle collision avoidance warning systems can aid drivers

An experiment was conducted to determine the effects of an in-vehicle collision avoidance warning system (IVCAWS) on driver performance. A driving simulator was driven by 135 licensed drivers. Of these, 120 received alerts from the IVCAWS when their headway to a lead car was less than 2 s, and the other 15 (the control group) received no alerts. Drivers received varied alert interfaces: auditory, visual, and multimodal. The system had varied levels of reliability, determined by both false alarm rate and failure of the IVCAWS to alert to short headway. Results indicated that the IVCAWS led to safer (longer) headway maintenance. High false alarm rates induced drivers to slow down unnecessarily; large numbers of missed alerts did not have any significant impact on drivers. Driver acceptance of the system was mixed. Interface played a role in driver reliance on the system, with the multimodal interfaces generating least reliance. Actual or potential applications of this research include IVCAWS interface selection for greater system efficacy and user acceptance and the advisability of implementation, even of imperfect systems, for drivers who seek to maintain a safer headway.     

Human performance models and rear-end collision avoidance algorithms

Collision warning systems offer a promising approach to mitigate rear-end collisions, but substantial uncertainty exists regarding the joint performance of the driver and the collision warning algorithms. A simple deterministic model of driver performance was used to examine kinematics-based and perceptual-based rear-end collision avoidance algorithms over a range of collision situations, algorithm parameters, and assumptions regarding driver performance. The results show that the assumptions concerning driver reaction times have important consequences for algorithm performance, with underestimates dramatically undermining the safety benefit of the warning. Additionally, under some circumstances, when drivers rely on the warning algorithms, larger headways can result in more severe collisions. This reflects the nonlinear interaction among the collision situation, the algorithm, and driver response that should not be attributed to the complexities of driver behavior but to the kinematics of the situation. Comparisons made with experimental data demonstrate that a simple human performance model can capture important elements of system performance and complement expensive human-in-the-loop experiments. Actual or potential applications of this research include selection of an appropriate algorithm, more accurate specification of algorithm parameters, and guidance for future experiments.     

基于LabVIEW的汽车防撞报警系统的设计

针对交通安全问题,设计了一种基于虚拟仪器的汽车防碰撞报警系统。给出了系统硬件、软件的设计方法和主要实验数据。该系统采用LabVIEW7.0编程,配合FMCW雷达传感器和高性能数据采集卡,可实现对前方车辆距离、速度的动态监测,当预见到有碰撞危险时,自动发出警示信息,帮助驾驶员及时刹车,避免碰撞事故发生。实测结果证明了系统的有效性。     

Multisensory in-car warning signals for collision avoidance

OBJECTIVE: A driving simulator study was conducted in order to assess the relative utility of unimodal auditory, unimodal vibrotactile, and combined audiotactile (i.e., multisensory) in-car warning signals to alert and inform drivers of likely front-to-rear-end collision events in a situation modeled on real-world driving. BACKGROUND: The implementation of nonvisual in-car warning signals may have important safety implications in lessening any visual overload during driving. Multisensory integration can provide synergistic facilitation effects. METHOD: The participants drove along a rural road in a car-following scenario in either the presence or absence of a radio program in the background. The brake light signals of the lead vehicle were also unpredictably either enabled or disabled on a trial-by-trial basis. RESULTS: The results showed that the participants initiated their braking responses significantly more rapidly following the presentation of audiotactile warning signals than following the presentation of either unimodal auditory or unimodal vibrotactile warning signals. CONCLUSION: Multisensory warning signals offer a particularly effective means of capturing driver attention in demanding situations such as driving. APPLICATION: The potential value of such multisensory in-car warning signals is explained with reference to recent cognitive neuroscience research.     

预防汽车追尾系统设计

介绍了预防公路追尾碰撞报警系统,系统由信息采集单元、中央控制单元、报警电路和显示输出单元构成.信息采集单元由4种传感器完成对车辆运行状态信号的采集,中央控制单元对输入信息进行分析、处理.完成防碰撞预测与判断功能,报警电路产生警报,提醒驾驶员采取措施以避免追尾碰撞事故发生.系统还具备显示功能.     

Effects of an in-vehicle collision avoidance warning system on short- and long-term driving performance

Many new in-vehicle systems focus on accident prevention by facilitating the driving task. One such driving aid is an in-vehicle collision avoidance warning system (IVCAWS), used to alert the driver to an impending collision. Our study evaluated the effects of an imperfect IVCAWS both on driver headway maintenance and on driver behavior in response to warning system errors. Our results showed that drivers tend to overestimate their headway and consequently drive with short and potentially dangerous headways, and that IVCAWSs are a useful tool for educating drivers to estimate headway more accurately. Moreover, our study showed that after a relatively short exposure to the system, drivers were able to maintain longer and safer headways for at least six months. The practical implications of these results are that the use of an IVCAWS should be considered for inclusion in driver education and training programs.     

基于单目视觉的车辆碰撞预警系统

基于单目视觉的车辆碰撞预警系统能够发现道路前方的车辆并估算出与前方车辆之间的距离,利用预警机制及时提醒驾驶员危险状况。车道检测和车辆识别是该系统需要解决的两个主要难题，提出了利用边缘分布函数EDF检测车道标线，利用车辆底部纹理和对称性特征识别车辆，并根据图像坐标系和世界坐标系之间的几何映射关系测距。实验结果表明，提出的方法能够有效检测出车道标线，并能很好地测定与前车的距离。     

Fuzzy collision avoidance system for ships

The paper discusses the problem of maritime traffic control. A model of the relative motion of two vessels is considered. An algorithm for the generation of alarms of various types in accordance with the verbal ship–ship danger level is considered. Navigation situations are separated into levels based on the ship’s maneuvering intensity and time to collision. A fuzzy decision-making system about the motion’s danger level that combines Mamdani and Sugeno fuzzy inference systems is proposed. The results of the numerical experiment that demonstrates the system’s operation under standard conditions and the results of the system’s field tests based on real ship traffic data in the waters adjacent to the port of Vladivostok are given.     

基于GPS/北斗的超低空防撞警告系统设计与实现

随着我国民航业尤其是通用航空领域的飞速发展,以及低空开放政策的实施,飞机数量迅速增长,空域变得更加繁忙和拥挤,同时增加了飞机在超低空飞行危险接近的可能性。同时,随着超低空无人机数目的增加,给民航系统带来了一定的安全隐患。基于GPS/北斗的超低空飞机防撞警告系统在超低空范围内为飞行器提供其附近空域中的交通状况,通过4G移动通信实现对飞行数据信息的实时接收处理和对飞行器的实时监控,在当飞行器存在潜在的安全隐患时,作出相应等级的警告并提前向相应飞行器发出警告信息,帮助飞行器选择安全的航路,避免飞行器间的碰撞危险。     

Influence of age and proximity warning devices on collision avoidance in simulated driving

OBJECTIVE: We conducted a set of experiments to examine the utility of several different uni- and multimodal collision avoidance systems (CASs) on driving performance of young and older adult drivers in a high-fidelity simulator. BACKGROUND: Although previous research has examined the efficacy of different CASs on collision avoidance, there has been a dearth of studies that have examined such devices in different driving situations with different populations of drivers. METHOD: Several different CAS warnings were examined in varying traffic and collision configurations both without (Experiment 1a) and with (Experiment 2) a distracting in-vehicle task. RESULTS: Overall, collision avoidance performance for both potential forward and side object collisions was best for an auditory/visual CAS, which alerted drivers using both modalities. Interestingly, older drivers (60-82 years of age) benefited as much as younger drivers from the CAS, and sometimes they benefited more. CONCLUSION: These data suggest that CASs can be beneficial across a number of different driving scenarios, types of collisions, and driver populations. APPLICATION: These results have important implications for the design and implementation of CASs for different driver populations and driving conditions.     

基于毫米波雷达的车辆防碰撞预警

防碰撞预警是主动安全中的一项重要技术。提出了一种基于毫米波雷达的防碰撞预警技术。首先在MHT模型下使用毫米波雷达检测出前方车辆,然后利用毫米波雷达获取的目标的速度和距离提出了以碰撞时间(Time to Collision,TTC)作为参数的防碰撞预警机制。通过实验分析,所提出的方法能够有效地将本车与前车保持在安全不碰撞的状态,可以应用到现有的主动安全系统中。     

Testing a multidimensional nonveridical aircraft collision avoidance system

OBJECTIVE: This study explores operators' ability to use a multidimensional, nonveridical control display. BACKGROUND: Veridical displays represent realistic scenes. State space displays represent nonveridical n-dimensional information based on informative coordinate axes plus variable features such as color and shading. Empirical investigation of state space displays is relatively new to human factors research. METHOD: Twelve licensed general aviation pilots flew flight scenarios, trying to deviate as little as possible from a preassigned course while still maintaining standard en route separation from traffic. Flight performance using only a veridical cockpit display of traffic information (CDTI) was compared with performance using the CDTI augmented by a 4-D nonveridical state space collision avoidance system (CDTI+4CAS). RESULTS: Using moderate traffic density and complex traffic geometry, the CDTI+4CAS condition showed performance superiority over the baseline CDTI-only condition for five of five dependent measures of maneuver efficiency, four of four measures of maneuver safety, and six of nine measures of user workload. CONCLUSION: Results suggest that nonveridical information display may enhance operator performance on a control task involving simultaneous processing of multidimensional information. APPLICATION: Nonveridical information displays have potential application wherever human control of multidimensional processes is involved.     

Traffic collision avoidance system: false injection viability

The Journal of Supercomputing - Safety is a simple concept but an abstract task, specifically with aircraft. One critical safety system, the Traffic Collision Avoidance System II (TCAS), protects...     

Decision support system for collision avoidance of vessels

Although there are many advanced systems to assist vessels with passing through narrow waterways, it continues to be a serious problem because of disturbance factors and geographic structure. By taking Istanbul Strait as a model for this study, we aimed to develop a decision support system and/or a guidance method to assist reciprocally passing vessels. The main purpose is to develop an Artificial Neural Network (ANN) that uses the data of manually controlled vessels to generate predictions about the future locations of those vessels. If there is any possibility of collision, this system is aimed to warn the operators in the Vessel Traffic Services (VTS) centre and to guide the personnel of the vessels. In this study, manually controlled and reciprocally passing vessels’ data were used (including coordinates, speed, and environmental conditions), neural networks were trained, and predictions were made about the locations of vessels three minutes after the initial point of evaluation (this duration was determined by considering the conditions of Istanbul Strait). With this purpose, we used data gathered from vessels and proved the success of the system, especially concerning predictions made during turnings, by determining the possibility of collision between two vessels three minutes after the data was gathered.     

Robotic Path Finding with Collision Avoidance Using Expert System

A rule-based expert system has been developed and used into a robotic planning system with collision-avoidance,The world model is represented as the knowledge data and stored in the knowledge base with rules.The expert system can find a collision-avoidance path.Otherwise.it shows the collision secton in which the moved object is blocked,Several examples for the different objects to pass through the different channels and to find a collision-free path have been tested.The simulating results of the palnner give out the planning sequence or blocked section(s).The output information is useful for making decision of the robot motion and modifyting the technological parameters of the world.     

多方位超声波倒车防撞系统设计

针对大货车等大型车辆中传统的超声倒车雷达只能探测水平方向,无法探测地面以及空中障碍物,很容易发生事故的问题,设计了一种基于超声波测距的多方位倒车辅助系统,系统可根据障碍物的类型发出相应的提示。实验测试结果表明:设计的系统不仅能够探测出水平方向和空中障碍物,还能探测出地面沟壑、凸起等。系统在30～400 cm范围内可以实现准确测距,最大误差不超过1. 6%,具有一定的研究和应用价值。     

CSMA with collision avoidance

Advances in local area networking have allowed users to run many different applications on one system. Users are now asking for greater access, more functions, more power and greater reliability. This requires that the system tasks should be distributed, and means that the interconnection system used should be highly reliable; ‘passive’, so that no failed component can bring the entire system down; support high through-put; and operate on low-cost cable. This paper describes a broadband transmission system based on a single, passive coaxial cable which detects possible collisions before the data is sent. Examples of two remote stations and two adjacent stations competing for transmission are given, along with performance comparisons of CSMA/CD and CSMA/CA.     

Distributed reactive collision avoidance

The work contained in this paper concerns a novel approach to the n-vehicle collision avoidance problem. The vehicle model used here allows for three-dimensional movement and represents a wide range of vehicles. The algorithm works in conjunction with any desired controller to guarantee all vehicles remain free of collisions while attempting to follow their desired control. This algorithm is reactive and distributed, making it well suited for real time applications, and explicitly accounts for actuation limits. A robustness analysis is presented which provides a means to account for delays and unmodeled dynamics. Robustness to an adversarial vehicle is also presented. Results are demonstrated in simulation.     

Maximum-miss aircraft collision avoidance

Aircraft densities in terminal areas increase each year, and the risk of collision grows proportionally. The maintenance of clearance between aircraft in this environment sometimes calls for evasive maneuvers, which depend on the relative position and relative velocity of two aircraft. In this study, small-amplitude maneuvers are found for either or both aircraft in near-miss configurations. Using practical low-order dynamics, individual maneuvers are found that maximize the miss distance. These optimal maneuvers combine longitudinal (speed) and normal (lift) accelerations. The signs of the accelerations of both aircraft depend on their magnitudes. An evasive climb maneuver, for example, becomes a dive maneuver if the acceleration amplitude exceeds a certain value. The maximum-miss maneuvers appear to have practical potential, because they can be determined on-line from estimated position data for both aircraft, without consideration of detailed inertial and aerodynamic properties of the aircraft. Recommended by H. Stalford