Showing papers on "Rear-end collision published in 2009"

Situation Assessment of an Autonomous Emergency Brake for Arbitrary Vehicle-to-Vehicle Collision Scenarios

Abstract: The autonomous emergency brake (AEB) is an active safety function for vehicles which aims to reduce the severity of a collision. An AEB performs a full brake when an accident becomes unavoidable. Even if this system cannot, in general, avoid the accident, it reduces the energy of the crash impact and is therefore referred to as a collision mitigation system. A new approach for the calculation of the trigger time of an emergency brake will be presented. The algorithm simultaneously considers all physically possible trajectories of the object and host vehicle. It can be applied to all different scenarios including rear-end collisions, collisions at intersections, and collisions with oncoming vehicles. Thus, 63% of possible accidents are addressed. The approach accounts for the object and host vehicles' dimensions. Unlike previous work, the orientation of the vehicles is incorporated into the collision estimation.

Pre-alarm method for preventing rear-end collision by following car

Abstract: The invention relates to an early warning method for preventing rear-end collision with a rearward vehicle and an early warning system thereof, wherein the method comprises the following steps: 1) arranging an early warning system for preventing rear-end collision with the rearward vehicle, which comprises an information acquisition unit, a system control unit comprising a singlechip as well as an early warning execution unit; wherein, an early warning module for preventing rear-end collision with the rearward vehicle is prearranged inside the singlechip, a collision warning range and a formula calculating the collision time of the vehicles are prearranged inside the early warning module for preventing rear-end collision with the rearward vehicle; 2) acquiring the distance between the rearward vehicle and own vehicle and relative speed information and acquiring own speed information; 3) calculating time of collision TTC and a warning time threshold of collision TTC_W of the rearward vehicle and own vehicle; 4) generating a control instruction in accordance with the difference value between the calculated time threshold of collision TTC and the warning time threshold of collision TTC_W of the rearward vehicle and own vehicle as well as the prearranged collision warning range; 5) sending corresponding warning information according to the control instruction The invention can real-timely and accurately monitor the relative motion state between own vehicle and the rear vehicle that travels in the same traffic lane, thus effectually preventing the rear-end collision of the vehicles that traveling at high speed

Development of Fuzzy-Based Bus Rear-End Collision Warning Thresholds Using a Driving Simulator

Abstract: The purpose of this paper is to develop rear-end collision warning thresholds with appropriate values of parameters for busses driving on freeways. Based on a bus-driving simulator, we design a simulation scenario of car following with emergency braking on freeways. Bus drivers working with a bus company are recruited to manipulate the simulation. The perception-reaction time, braking deceleration rate, and buffer of bus drivers' responses to a lead vehicle suddenly braking are collected and analyzed as parameters. Results indicate that not all the subjects have the same value in each parameter. Hence, the values of parameters in the bus rear-end collision warning threshold equations should be differentiated from various bus-driving characteristics. This paper further uses a fuzzy set theory to develop the safety membership function of each parameter and deduces 27 warning threshold equations. By these threshold equations, a rear-end collision warning algorithm for busses driving on freeways is also recommended.

PRE-SAFE® in rear-end collision situations

Abstract: In 2002 the first bridge between active and passive automotive safety was built. The MY03 MercedesBenz S-Class was the first car in the world that implemented preventive measures for occupant protection which took effect before the actual impact occurred. Meanwhile the name “MercedesBenz PRE-SAFE ® System” became well known. Since then many other cars from various car manufacturers have adopted this principle of a “natural protection reflex”. In order to detect dangerous situations or upcoming accidents, various sensor systems are being used in these cars today. In addition to sensors that keep an eye on the driving dynamics or on the driver reaction, the use of radar sensors or cameras has become common during the past few years. Almost all of those systems observe the area in front of the car and therefore address situations with an increased risk for a frontal impact. Very few systems presented up to now are capable to “look” backwards and thus detect an imminent rear impact. This paper presents the Mercedes-Benz approach to integrate this type of accident into the PRE-SAFE ® System. The paper covers the issue of detecting collision objects on the basis of radar data. And it presents a cascade of precautionary actions that can improve occupant protection in rear-end accident situations. In particular, the purpose and benefit of a preventive increase of brake pressure is discussed, as well as taking into account further actuators such as a reversible seat belt pretensioner or an active headrest. In order to substantiate the benefit of such a system several evaluation charts on the reduction of the impact severity, the dummy loads and the estimated risk of whiplash injuries are included. Based on accident simulations there are also evaluations about the reduction of the “accident radius” and thus the risk of a secondary impact. Finally the question of an appropriate electronic architecture for such an integral safety system is touched upon.

New approach of accident benefit analysis for rear end collision avoidance and mitigation systems

Abstract: In Germany approximately 12% of all accidents with persons injured and approximately 20% of all material damage accidents are caused by cars in rear end collisions. As a consequence, Bosch is introducing collision avoidance and mitigation systems for rear impact scenarios. Warning, brake support, and autonomous emergency braking are part of Bosch's Advanced Emergency Braking Systems which address such accidents. This study determines the benefit of these assistance and safety systems and estimates the collision avoidance capability considering the driver's behavior. By analyzing representative accidents with injuries from the GIDAS (German In-Depth Accident Study) database, a high potential for collision warning and avoidance systems was determined. For the first time in such a study, this analysis considers the effects of different driver reactions due to warning, braking support, or autonomous braking with respect to the possible driver behavior. For this, a calculation method was developed and used for evaluating the accidents automatically. Both accident avoidance and average speed reduction was determined for different driver types, warning strategies and applications. From the results, an avoidance ratio of 38% for Predictive Collision Warning up to 72% for Automatic Emergency Braking, of all rear-end accidents can be expected for a realistic driver. Therefore it is estimated that 3 out of 4 accidents with severe injuries could be avoided based on the Emergency Brake Assist function and assuming a 100% installation rate. The potential to reduce collision speed in non avoided accidents is calculated on an average basis and is determined to be between 25% and 55% for the realistic driver. The results in the analyses show the high efficiency of the Bosch AEBS functions in avoiding accidents or mitigating injuries by reducing collision speed and should encourage the introduction of Advanced Emergency Braking Systems across a wide range. The full text of this paper may be found at: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv21/09-0281.pdf For the covering abstract see ITRD E145407.

Rear-end collision warning system on account of a rear-end monitoring camera

Abstract: The objective of this study is to establish a rear-end collision warning system for an advance safety vehicle (ASV) by using a mounted rear-end monitoring camera. The paper attempted to analyze the driving environmental data and built up the rear-end collision warning logic on account of image processing. The main idea of the warning system is to prevent accidents caused by inattentive drivers. In recent years, the parking assistance system with ultrasonic sensors and rear-end camera, has almost become the basic equipment in vehicles. However, the parking assistance system is only activated when the equipped vehicle is reversing. This study tries to apply the rear-end monitoring camera's images as the rear-end collision surveillance for approaching driving. This improves the camera's utility when the parking assistance system in idleness. In this study, the practical system is mainly equipped to a testing car with an industry personal computer, an on-board LCD and a CCD camera. By image processing, the relative distance, velocity, and acceleration to the follower vehicle are measured. This paper developed the dynamic threshold from the relative data and the drivers' perceptive reaction time to issue the warning for the drivers. The α-β-γ filter was applied to process the relative data smoothly. The experiment result was successful on the off-line video tests. This study convinces that the developed rear-end warning system could appropriately warn the equipped driver when its following car does not keep in a safe distance.

A forward collision warning (FCW) performance evaluation

Abstract: This paper describes tests performed by the National Highway Traffic Safety Administration (NHTSA) to evaluate the forward collision warning (FCW) systems installed on three late model passenger cars. NHTSA defines an FCW system as one intended to passively assist the driver in avoiding or mitigating a rear-end collision via presentation of audible, visual, and/or haptic alerts, or any combination thereof. The test maneuvers described were designed to emulate the top three most common rear-end pre-crash scenarios reported in the 2004 GES database. FCW system performance was quantified by specifying the average time-to-collision (TTC) between the subject vehicle (SV) and principle other vehicle (POV) at the time of the SV's FCW alert. The full text of this paper may be found at: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv21/09-0561.pdf For the covering abstract see ITRD E145407.

Analysis on Traffic Safety Distance of Considering the Deceleration of the Current Vehicle

Abstract: In the light of the conditions that the results of traditional criticality safety vehicle distance are hardly able to guarantee the safety in the sudden reaction of the current vehicle, through studying the conditions of traditional criticality safety distance, considering the impact of abnormal deceleration of the current vehicle on following vehicle, and different response time of drivers, a new calculation method is re-established for criticality safety distance. It not only can meet the demands safety of expressway better, but also has positive significance for the prevention of rear-end collision.

Design of a Highly Safe Model Vehicle for Rear-End Collision Avoidance Considering Multiple Faults of Sensors

Abstract: This paper presents design of a highly safe driving control system using different kinds of sensors and its evaluation in order to avoid the rear-end collision of the model vehicle. The feature of the control is that an appropriate combination of sensing information from different kinds of sensors is introduced to reduce the occurrence of multiple faults. It is shown in the results of analysis of numerical values that the reliability of the combination of different kinds of sensors is higher than that of the combination of the same kind of sensors. Moreover, the systematic design of the model vehicle is proposed, and it is also shown in the experiment that the rear-end collision avoidance can be achieved even if a fault occurs at any sensor.

Feasibility of Using Event Data Recorders to Characterize the Pre-Crash Behavior of Drivers in Rear-End Collisions

Abstract: This paper investigates the feasibility of using event data recorders (EDRs) to characterize the crash avoidance behavior of drivers involved in rear end collisions. The study is based upon the records of 112 crashes from NASS/CDS 2000-2007 with associated EDR pre-crash data and of sufficient severity to deploy the frontal air bag. The study examined three factors affecting driver response to an impending rear collision: driver age, driver alcohol use, and road lighting condition. Crash avoidance actions of the drivers were inferred from the pre-crash EDR records of vehicle speed, throttle position, engine speed (RPM), and service brake status five seconds prior to impact. Factors considered included time of brake application prior to impact, peak braking deceleration, and the time history of throttle position. For these cases, this study combined EDR pre-crash records with NASS/CDS case records including scene diagrams and site photos to determine driver crash avoidance actions. The full text of this paper may be found at: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv21/TOC.pdf For the covering abstract see ITRD E145407.

Japan New Car Assessment Program for Minor Neck Injury Protection in Rear-End Collisions

Abstract: The JNCAP intends to introduce a minor neck injury protection performance evaluation test method within the JNCAP program. The research began with a 4-year project in 2005. In the first year, rear-end vehicle collision tests were conducted using a MDB to ascertain vehicle rear crash characteristics. In the second year, crash tests were conducted to allow changing the test conditions such as braking effect and excluding the influence of the MDB honeycomb. Basic data collected included floor G during a crash and measurement of the dummy injury level. In the third year, dynamic component sled tests were conducted to select an actual vehicle crash test or sled test. It was found that the vehicle seat structure has a greater influence on the results than the vehicle structure. Additionally, in examining the sled acceleration pulse which represents the vehicle crash, it was found that the crash characteristics of recent vehicles exhibited a triangular pulse rather than a trapezoidal pulse in the actual rear-end vehicle crash test. Delta-V is determined based on the cumulative figures for the rear-end crash accident speed rate. In the final year, all research results and conclusions were incorporated in our test protocol, and trial tests were conducted using the draft test procedure, which consists of the dynamic component sled test with a generic triangular pulse of delta-V=20 km/h. Effective evaluation indices will be finalized using recent biomechanical information. The full text of this paper may be found at: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv21/09-0364.pdf For the covering abstract see ITRD E145407.

A rear-end collision warning system for drivers with support vector machines

Abstract: The paper proposes a rear-end collision warning system for drivers, where how to evaluate the risk of collision is critical. In the proposed system, the time-to-collision assuming a constant relative acceleration is employed as a subjective index of risk based on the collected data in an unconstrained drive and the discussion from a theory of visual control. The system produces an alert when it detects anomaly of the index using the one-class support vector machine, which is trained with the aforementioned data. Some cross-validation experiments show the effectiveness of the system.

Study on the Mathematics Model for the Forewarning System of Automobile Rear-end Collision Avoidance

Abstract: Rear-end collision is a common traffic accidents,and it′s an important aspect of vehicle active safety research.An improved mathematics model was set up in light of the analysis of the rear-end forewarning system design requirements and the actual kinematical analysis of braking process.The control strategy in the concept of forewarning degree with the setting of road traffic pattern was analyzed.Simulation results show that the model could be applied to variety traffic conditions through the setting of road traffic patterns,and it would give judgment of forewarning grade by collecting the real-time status of both vehicles.

Rear-end collision prevention device with accident vehicle

Abstract: PROBLEM TO BE SOLVED: To prevent the occurrence of a secondary disaster by automatically displaying a warning for preventing rear-end collision independently of the consciousness of a driver of an accident vehicle to make a driver or the like of a succeeding vehicle to recognize the existence of the accident vehicle. SOLUTION: In a vehicle accident such as rear-end collision, gas is supplied into a balloon 5 interlocking with the operation of an airbag system installed in the vehicle to instantaneously distend and develop the folded balloon 5, the distended balloon 5 is automatically discharged to the outside of the vehicle, and floated in the air to inform a driver of a succeeding vehicle or the like of the existence of an accident vehicle stopped on a road. COPYRIGHT: (C)2009,JPO&INPIT

Research on Safe Distance Model in Avoiding Automobile Rear-end Collision

Abstract: Combining variables such as speed,driver's state,weather state,road state of two trucks going in the same direction together,using the kinematics analytical method,the mathematical model of the safe distance in avoiding automobile rear -end collision is set up. According to the mathematical model of the safe distance,the flow diagram is educed for judge whether the car is safe from the current state or not.

Device for preventing rear-end collision of vehicle

Abstract: The utility model discloses a device for preventing rear-end collision of a vehicle, relating to an automatic stopping device for preventing rear-end collision when the vehicle at the front stops suddenly, and mainly aiming at solving the problem that when meeting an emergency, people can not stop the vehicle in time. The device for preventing rear-end collision of a vehicle comprises a telemeter, a controller and a braking system. The telemeter is arranged on the front end of the vehicle for measuring the distance between the vehicle and the object at the front and transmitting a distance signal to the controller; when the distance between the vehicle and the object at the front is less than a certain value, the controller starts the braking system for stopping the vehicle. The utility model is provided with the braking system, so that when the distance between the vehicle and the object at the front is less than a certain value, the controller starts the braking system for avoiding the traffic accident.

Research on Fuzzy Inference of Driver's Risk Perception of Rear-End Collision on Freeway

Abstract: The purpose of this research is to develop a microscopic indicator of risk perception of rear-end collision based on fuzzy inference system in order to effectively surrogate the traditional evaluation method based on the accident data. The factors that result in the rear-end collision such as the relative speed, the acceleration of leader vehicle, car-following safety distance are taken as the fuzzy input variables and the value of risk perception of rear-end collision is regarded as the output variable. Meanwhile, considering the effect of the weather, the perception reaction time can be also obtained by the fuzzy inference system so as to calculate car-following safety distance. Finally, the research results can provide a support for the early warning technology of traffic accidents.

Automobile anti-rear end collision safety prewarning apparatus

Abstract: The invention discloses a safety pre-warning device for preventing rear end collision of automobiles. The device comprises a central control device, a signal output device, a signal receiving device, a distance measuring device, and a speech warning device. The signal output device is positioned in the head of the automobile and is connected with the central control device; the central control device controls the speech warning device to give out sound; and the tail of the automobile is provided with the signal output device transmitting a signal backwards. The safety pre-warning device for rear-end collision of the automobile can detect whether the distance between a front automobile and a rear automobile is dangerous in time; and when the distance between two automobiles is too close, the device can give out sound in time to remind a driver of the rear automobile of driving at reduced speed and keeping safe distance.

Research of the Critical Safety Distance Between Two Moving Vehicles in Rear-end Collision Avoidance

Abstract: Since an increasing number of traffic accidents has become a serious social problem,the problem should be resolved to reduce the loss and injury of traffic accidents.When vehicles are moving,the back driver should make corresponding changes of driving behaviors in order to prevent the possible collision while a front vehicle is slowing down or there are some obstacles.To improve initiative security of vehicle at high speed,the authors firstly study the athletic characteristics for vehicle in rear-end driving.Based on the running state of front vehicle,the authors bring a formula of the critical safety distance between two moving vehicles,which is useful to the drivers.

The Effect of ABS as a Preventive Safety Device: The Result of Statistical Analysis Using Integrated Road Traffic Accident Database

Abstract: The object of this study is to evaluate the effect of Antilock Braking System (ABS) as a preventive safety device by statistical analysis of integrated road traffic accident database. The road traffic accident data including driver and road environment condition and the registered vehicle data including safety device were integrated. The risk of being struck from behind while stopping is not influenced by the driver characteristic of the struck vehicle. So the number of those vehicles/drivers is able to be considered a quasi-induced exposure, and the relative accident rates for some combinations of 7 factors listed later were calculated. Data from 253,035 cars, which were involved in a traffic accident from the year 2002 to 2007, manufactured from the year 1993 to 2000 and driven by a sober, private purpose and seat-belted driver, were analyzed by 7 factors; sex and age of driver, types of collisions, day/night, road surface condition, with/without a passenger and with/without ABS. ABS is expected to reduce the accident rate, especially for some collision types which could be prevented by keeping wheels unlocked. The results shows; 1) the accident reduction effect of ABS on wet road surface was greater than on dry road surface, and 2) ABS reduced the relative accident rates of a rear-end collision by 1-38% and a single vehicle collision by 10-33%. There are several discussions about the validity of the quasi-induced exposure method. But the effect of ABS was confirmed by considering the interactive effect with other factors such as age of driver or with/without a passenger. Further studies are required for precise discussion. The developed integrated database and the proposed method are also useful to evaluate other preventive safety devices. The full text of this paper may be found at: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv21/09-0436.pdf For the covering abstract see ITRD E145407.

PRE-SAFE(super R) in Rear End Collision Situations

Abstract: In 2002 the first bridge between active and passive automotive safety was built The MY03 Mercedes- Benz S-Class was the first car in the world that implemented preventive measures for occupant protection which took effect before the actual impact occurred Meanwhile the name "Mercedes- Benz PRE-SAFE (super R) System" became well known Since then many other cars from various car manufacturers have adopted this principle of a "natural protection reflex" In order to detect dangerous situations or upcoming accidents, various sensor systems are being used in these cars today In addition to sensors that keep an eye on the driving dynamics or on the driver reaction, the use of radar sensors or cameras has become common during the past few years Almost all of those systems observe the area in front of the car and therefore address situations with an increased risk for a frontal impact Very few systems presented up to now are capable to "look" backwards and thus detect an imminent rear impact This paper presents the Mercedes-Benz approach to integrate this type of accident into the PRE-SAFE (super R) System The paper covers the issue of detecting collision objects on the basis of radar data And it presents a cascade of precautionary actions that can improve occupant protection in rear-end accident situations In particular, the purpose and benefit of a preventive increase of brake pressure is discussed, as well as taking into account further actuators such as a reversible seat belt pretensioner or an active headrest In order to substantiate the benefit of such a system several evaluation charts on the reduction of the impact severity, the dummy loads and the estimated risk of whiplash injuries are included Based on accident simulations there are also evaluations about the reduction of the "accident radius" and thus the risk of a secondary impact Finally the question of an appropriate electronic architecture for such an integral safety system is touched upon The full text of this paper may be found at: http://www-nrdnhtsadotgov/pdf/esv/esv21/09-0129pdf For the covering abstract see ITRD E145407

Rear end collision sensor loading structure for vehicle

Abstract: PROBLEM TO BE SOLVED: To provide a rear end collision sensor loading structure capable of detecting rear end collision of a vehicle in a short period of time. SOLUTION: A rear satellite sensor 24 to detect the rear end collision of an automobile 11 is provided on an inner surface of a lower back panel 32 to face the front side in the longitudinal direction of the vehicle with a prescribed interval against a rear bumper reinforcement 30 to suspend rear end parts of a pair of left and right rear side members 34 arranged in parallel in the vehicle widthwise direction on a rear satellite sensor loading structure 10 for the vehicle. COPYRIGHT: (C)2010,JPO&INPIT

Automatic operation device of railway model, two-train automatic operation method, and two-train rear-end collision preventing automatic operation method of railway model

Abstract: PROBLEM TO BE SOLVED: To provide an operation method capable of automatically operating two trains at a constant speed and automatically preventing a rear-end collision when two trains are made to run in the same direction without special work on the power car of a train. SOLUTION: In the operation method, the power car of a railway model such as N gauge and lines in which entire line is divided into a plurality of sections 1, 2, 3, 4 and 5 and insulated respectively are used. The device includes a microcomputer section for processing of detecting on which section of the line the train is present regardless of the running or stop of the power car and detecting speed information, or the like, and a personal computer section 50 for transferring control information to the microcomputer section. An automatic operation is performed, automatic stop is performed, a rear-end collision is prevented when two trains are operated in the same direction, and various high-grade automatic operations are made possible. COPYRIGHT: (C)2011,JPO&INPIT

Design of new anti-vehicle rear-end collision based on AVR

Abstract: Aiming at the high frequency of vehicle rear-end collision,a safe device design of anti-vehicle rear-end collision is presentedIn the design,the high-performance,low-power 8-bit AVR microprocessor ATmega8L is utilized as a core combined with Hall-type speed sensor,laser-radar ranging devices and the acceleration sensor MMA7260QTThe design considers both the front and back of a car,and overcomes the drawbacks of former designs in which only the front or the back of the car is considered,so it is especially suitable for high-speed,night or the beginner’s driving

Rear-end collision prevention algorithm for vehicle

Abstract: A moving back rear-end collision protecting algorithm for the vehicles is provided that the degree of danger by the reverse speed of vehicle, and the distance between the rear object and vehicles, are computed on a real time basis in the rear movement. A moving back rear-end collision protecting algorithm for the vehicles comprises following steps: a first step(S1) which the distance with the rear object and vehicle driving status data detected in the ultrasonic sensor are input; a second step(S2) which computes the throttle switching speed by using the change of the opening amount according to the time; a third step(S3) which if the brake is not in operation, confirms the present speed of the vehicles thereafter after confirming the approval with first phase; a fourth stage(S4) which if the vehicles goes back in the third step, computes the collision prediction distance; a fifth step(S5) computing the rear-end collision expected time by the distance computed in the fourth stage and running speed; a sixth step(S6) classifying the emergency signal corresponding to the rear-end collision expected time computed in the fifth step; a seventh step(S7) which if the vehicles is the stationary state in the third step, classifies the emergency signal corresponding to the distance of the rear object and vehicles; an eighth step(S8) notifying operator of the emergency signal classified in the sixth step and the seventh step.