Showing papers on "Rear-end collision published in 1994"

Development of a rear-end collision avoidance system with automatic brake control

Abstract: We have studied active safety technologies from the standpoint of “collision avoidance”. This paper describes a rear-end collision avoidance system with automatic brake control, which avoids a collision to the vehicle in front caused by inadvertent human errors using automatic emergency braking. The system is comprised of four key technological elements, headway distance measurement using scanning laser radar, path estimation algorithm with vehicle dynamics, collision prediction to the vehicle in front by a safe/danger decision algorithm, and longitudinal automatic brake control.

Hydraulic automotive vehicle brake system

Abstract: A hydraulic automotive vehicle brake system with an actuating assembly that is attached to the splashboard of the automotive vehicle and is operable by the vehicle brake pedal. In order to reduce the possibility of risk to the driver during a collision (especially a rear end collision), the present invention provides a system which simulates an increase volume requirement of the brake system, thus permitting increased actuating travel of the actuating assembly.

Using the reamacs model to compare the effectiveness of alternative rear end collision warning algorithms

Abstract: This paper presents the results of an analytical study of alternative rear end collision-avoidance algorithms using the Ford REAMACS simulation. REAMACS (Rear End Accident Model And Countermeasure Simulation) models rear end collision situations in freeway traffic and estimates the benefits of collision avoidance systems. Previously reported applications of the model indicate that the end crash warning system has the potential for a 60 percent reduction of the number of serious rear end crashes in freeway traffic. The present study confirmed and extended those findings to a broader range of conditions. Two different collision warning algorithms were analyzed: (1) a Closing Rate algorithm (CRA) which provides a warning only if the following vehicle has a positive closing rate with the lead vehicle, and (2) a Stopping Distance algorithm (SDA) which provides advanced warning of a potential hazard. The Stopping Distance Algorithm was more effective than the Closing Rate algorithm, with effectiveness rates approaching 100 percent, but gave 440 to 1,100 times more warnings than the Closing Rate Algorithm. Whether or not drivers would comply with such warnings is an issue.

Rear-end collision preventive device of vehicle

Abstract: PURPOSE: To beforehand prevent a rear-end collision with a preceding vehicle by automatically operating vehicle braking force necessary to avoid the rear-end collision even if a driver does not perform proper brake operation. CONSTITUTION: A rear end collision preventive device is provided with a brake actuator (g) to generate braking force of a vehicle, a means (a) to measure an inter vehicle distance from a preceding vehicle, a means (c) to calculate relative speed with the preceding vehicle from a change in this measured value, a means (d) to find vehicle braking force necessary at a minimum to avoid a rear-end collision according to the relative speed and the inter-vehicle distance, a means (b) to detect a brake operation quantity, a means (e) to find artificial vehicle braking force from this detecting value and a means (f) to control the brake actuator (g) on the basis of a larger value by comparing these two vehicle braking forces with each other.

Using the REAMACS model to compare the effectiveness of alternative rear end collision warning algorithms

Abstract: This paper presents the results of an analytical study of alternative rear end collision-avoidance algorithms using the Ford REAMACS simulation. REAMACS (Rear End Accident Model And Countermeasure Simulation) models rear end collision situations in freeway traffic and estimates the benefits of collision avoidance systems. Previously reported applications of the model indicate that the end crash warning system has the potential for a 60 percent reduction of the number of serious rear end crashes in freeway traffic. The present study confirmed and extended those findings to a broader range of conditions. Two different collision warning algorithms were analyzed: (1) a Closing Rate algorithm (CRA) which provides a warning only if the following vehicle has a positive closing rate with the lead vehicle, and (2) a Stopping Distance algorithm (SDA) which provides advanced warning of a potential hazard. The Stopping Distance Algorithm was more effective than the Closing Rate algorithm, with effectiveness rates approaching 100 percent, but gave 440 to 1,100 times more warnings than the Closing Rate Algorithm. Whether or not drivers would comply with such warnings is an issue.

Motor vehicle hydraulic brake system

Abstract: The proposal is for a motor vehicle hydraulic braking system with an actuating unit which is secured to the splashboard of a motor vehicle and actuated by a brake pedal. In order to eliminate the risk of injury especially in a rear end collision, the invention proposes that means (12 - 17, 22, 23, 26, 27) be provided with which, in the event of an accident resulting in deformations of the front of the vehicle, an increased volume requirement for the braking system is simulated, thus producing an increase in the actuating travel of the actuating unit (1, 2).

IVHS Countermeasures for Rear-End Collision, Task 1 Vol. VI: Human Factors Studies

Abstract: The media of specific interest to this study is that of microwave radar. Acoustic radar has been rejected due to its limitations in adverse weather conditions. Frequency range is between 22 and 94 GHz with the range around 60 GHz having possible advantages due to atmospheric attenuation in this bandwidth. However, increase frequency corresponds to higher cost. The modulation is most often in one of the following forms: pulsed (well suited for multiple targets but expensive), frequency modulation in continuous wave or FM/CW (cheaper with increased cost in signal processing), and bi-frequency or diplex Doppler (simplest but not effective in for multiple targets and rain clutter). Braking systems have been approached differently. In the US the approach has been to reduce the range of the radar to 50m on freeways (35m on curves) and incorporate automatic braking to improve efficiency. This is effective in reducing the number of false alarms. Due to the higher speeds in Europe, the approach there has been to focus on prevention through Previous work done about anti-collision (ac) radar is reviewed with requirements for the components of the systems given. The main requirements of ac radar are: physical media for target detection, automatic or manual braking, autonomous or cooperative systems, and antenna diagram warnings. Ranges in excess of 1OOm are necessary which results in an increase in false alarms. Autonomous systems are independent of other vehicles. Cooperative systems require reflectors on targets. The advantage of the latter being the possibility of vehicle information exchange. However, the danger of not detecting an unmarked target may be great enough to eliminate this option. The antenna diagram must be such to minimize false alarms while maximizing hazard detection. This is accomplished by confining the horizontal range to one lane. Vertically, the radar must not pick up overpasses or tops of tunnels whose height is generally around 6m. As such, the effective beam size is 2.5 degrees horizontally and 3.5 to 5 degrees in elevation,

Double rear-end collision preventive device

Abstract: PURPOSE:To prevent double rear-end collision in advance by mounting a hazard switch at the front part of a vehicle body. CONSTITUTION:When a serious accident such as double or triple rear-end collision which often happens on a superhighway occurs, a hazard switch 3 mounted at the front part of a vehicle body is operated automatically to make a hazard lamp go ON, by which the information of the accident of a precedent car is given to a succeeding car as earlier as possible to provide the reduction in the nor of accidents and higher safety of a driver and a fellow passenger in an accident vehicle and prevent double rear-end collision beforehand. Moreover, an impact sensing switch 3 is mounted at the front part of the vehicle body. The impact sensing switch 5 comes into action when a higher impact than a fixed level is received due to a severe accident such as double or triple rear- end collision on a superhighway or the like to make the hazard lamp go ON.

Motor vehicle hydraulic braking system

Abstract: The proposal is for a motor vehicle hydraulic braking system with an actuating unit which is secured to the splashboard of a motor vehicle and actuated by a brake pedal. In order to eliminate the risk of injury especially in a rear end collision, the invention proposes that means (12 - 17, 22, 23, 26, 27) be provided with which, in the event of an accident resulting in deformations of the front of the vehicle, an increased volume requirement for the braking system is simulated, thus producing an increase in the actuating travel of the actuating unit (1, 2).

Advanced indication of braking : a practical safety measure for improvement of decision-reaction time for avoidance of rear-end collisions

Abstract: The objective of this paper is to show that an Advanced Brakelights Warning System (ABWS) device improves the detection-reaction time for avoidance of rear-end collisions and to recommend its installation. The paper shows that this system provides the optimal evaluation available today to rear-end collisions caused by tailgating, in terms of cost/ performance/public acceptability ratio.

Alarm device for rear-end collision prevention of vehicle

Abstract: PURPOSE:To prevent the read-end collision of a vehicle with a subsequent vehi cle caused by restoppage of this vehicle just after it starts at a T-character road and a cross-point, etc., where a visuality is bad. CONSTITUTION:This device is provided with a brake lamp 75 notifying a subsequent vehicle of the possibility that the vehicle stops and a stoppage recognition means recognizing that the vehicle stopped at a place such as a T-character road and a cross-point, etc., where a visuality is bad. The attention of the driver of the subsequent vehicle is provoked by tuning on or flashing the brake lamp 75 from the point of time when the vehicle stopped at the place till the vehicle starts and becomes a prescribed running state having no possibility of a restoppage. The stoppage recognition means recognizes the stoppage of a specific place by detecting the marker provided on roads by a marker sensor 65.

Rear-end collision prevention and crime prevention device

Abstract: PURPOSE:To prevent a vehicle parking on a road with its lamps turned off at night from being collided from behind CONSTITUTION:A light receiving circuit 8 for detecting the light of a lamp is mounted at the rear part of a vehicle When the light receiving circuit 8 detects the light, a number plate 2 and/or a flickering lamp are lighted to tell the existence of a parking vehicle to a driver in a rear vehicle At night, characters in the number plate 2 are made luminous to read them even without approaching the vehicle, so it is possible to provide a crime protection effect

Warning device for preventing rear-end collision between vehicles

Abstract: PURPOSE:To prevent the rear-end collision between a drivers own vehicle reducing speed due to traffic congestion and the following vehicle in the specific place in tunnels or the like. CONSTITUTION:The device is provided with a warning lamp 55 to alarm the following vehicle, a marker sensor 45 detecting the marker provided on the surface of road and recognizing the travelling of the drivers own vehicle on a specific place, and a car speed sensor 42 detecting the speed of the drivers own car. If the drivers own car speed is slower than the prescribed car speed when the drivers own car travels the specific place, the warning lamp 55 is lighted up to alarm. The warning is released when the distance between the drivers own vehicle and the following vehicle is narrowed less than the prescribed distance.

Rear-end collision prevention and alarm apparatus

Abstract: PURPOSE:To obtain a rear-end collision prevention and alarm apparatus wherein a data processing amount is reduced, a high-speed processing operation can be performed in a real-time manner and an alarm is issued in order to prevent a collision against a moving object such as a car or the like while the object is being tracked. CONSTITUTION:Quantized data on the same coordinate point is compared by a comparison means 2, a difference is taken and shading difference data is produced. The shading difference data is accumulated in the row direction at every row by a row accumulation means 3 and in the column direction at every column by a column accumulation means 4. A tracking means 5 tracks a preceding vehicle by the output of the row accumulation means 3, and a distance measuring means 6 measures a distance up to the preceding vehicle by the output of the column accumulation means 4. By means of the distance up to the preceding vehicle and by means of the speed of an own vehicle measured by a speed measuring means 7, an alarm judgment means 8 judges whether an alarm in order to prevent a collision is issued or not, and an alarm means 9 issues the alarm by the result of the judgment.