Showing papers on "Collision avoidance system published in 1997"

Adaptive ground collision avoidance system

Abstract: A ground collision avoidance system that exhibits improved accuracy and performance by integrating with all other aircraft systems including guidance systems, navigation systems, digital terrain elevation databases, mission computers, and radar altimeters. The ground collision avoidance system fully utilizes active onboard sensors in combination with the knowledge of terrain and obstacle data contained in databases. Furthermore, the ground collision avoidance system provides a multiple processing path to determine numerous predicted flight paths based on a number of reasonable assumptions regarding the aircraft flight during a predetermined amount of time. By using predictive flight path schemes a realistic estimate of the predicted flight path envelope can be determined and then this information can be used in conjunction with accurate terrain elevation databases to determine whether a ground collision condition exists. On the basis of these calculations, appropriate warnings can be provided to the air crew as well as suggested maneuvers to avoid ground collision.

The format and presentation of collision warnings

Abstract: This paper reports on two studies focusing on the design of collision avoidance headway displays. The first study aims at examining interface issues relating to the headway information to drivers. It investigates integrated visual and auditory warnings. The purpose of the second study is to examine two particular factors that may affect drivers' braking responses in their use of an experimental Collision Avoidance System. It looks at the effects of both the absolute speeds of the target and following vehicle and the relative speed differences between the two vehicles.

Experimental Studies Of Pilot Performance At Collision Avoidance During Closely Spaced Parallel Approaches

Abstract: Efforts to increase airport capacity include studies of aircraft systems that would enable simultaneous approaches to closely spaced parallel runway in Instrument Meteorological Conditions (IMC). The time-critical nature of a parallel approach results in key design issues for current and future collision avoidance systems. Two part-task flight simulator studies have examined the procedural and display issues inherent in such a time-critical task, the interaction of the pilot with a collision avoidance system, and the alerting criteria and avoidance maneuvers preferred by subjects.

Collision avoidance as a differential game: real-time approximation of optimal strategies using higher derivatives of the value function

Abstract: Contemporary developments of on-board systems for automatic or semi-automatic driving include car collision avoidance. For this purpose a worst case approach based on pursuit-evasion differential games is investigated. On a freeway a correct driver (evader) is faced with a wrong driver (pursuer) ahead. The correct driver tries to avoid a collision against all possible wrong driver's maneuvers and additionally tries to stay on the freeway. The representation of an optimal collision avoidance strategy along a lot of optimal paths is used to synthesize a collision avoidance strategy globally by means of Taylor series expansions of the value function's gradient. Examples of simulations which proved satisfactory performance of the on-board collision avoidance system against various typical maneuvers of wrong drivers are presented.

Collision avoidance system

Abstract: A collision avoidance system for a warning aircraft includes a transmitter and receiver for interrogating the transponder of a warned aircraft. A computer to be installed in the warning aircraft is programmed with the distances or rates of closure at which the warning aircraft and the warned aircraft constitute traffic for one another. When the computer has determined that the warning aircraft and a warned aircraft constitute traffic for one another, a warning system broadcast an appropriate vocal warning.

A crash avoidance system based upon the cockroach escape response circuit

Abstract: A crash avoidance system for automobiles is developed based upon a distributed network of artificial neurons that mimic the neural organization of the escape system in the American cockroach. The cockroach escape circuit is shown to be an excellent source of inspiration for the development of a collision avoidance system. The crash avoidance system is implemented in an artificial neural network which is trained off-line, but then is shown to produce real-time performance. A collision avoidance scheme which makes use of a crash alarm strategy is developed for training the neural network. A dynamic model of a four-wheeled vehicle with front wheel steering and realistic performance constraints is used to test the crash avoidance system. Simulation results show that the well-trained neural network causes successful, reflexive crash avoidance behaviors in a dynamic environment without a priori information.

Benefits estimation for selected collision avoidance systems

Abstract: This paper presents safety benefits of three collision avoidance systems in terms of the number of crashes that might be avoided. The results were estimated in a recent preliminary study conducted by the National Highway Traffic Safety Administration of the United States (U.S.) Department of Transportation. The three selected systems address rear-end, lane change, and single vehicle roadway departure crashes which accounted for about 3.14 million police-reported crashes in the U.S. in 1994. A basic methodology was developed and applied to each of the three systems, using experimental data from driving simulator studies and on-road tests where subjects drove with and without the assistance of a collision avoidance system in a variety of driving situations and surrounding conditions. Collectively, the three systems have the potential to reduce about 1.8 million police-reported crashes annually in the U.S. based on 1994 crash statistics. For the covering abstract, see IRRD 490001.

Evolution to an Automated Highway System

Abstract: In the Precursor Systems Analyses (PSA) sponsored by the Federal Highway Administration in 1993, several of the researchers addressed how AHS would be first introduced to the market. The researchers identified several problems to be overcome including driver acceptance and the ability of state and regional departments of transportation to operate and maintain an AHS.(1–3) The researchers concluded that one of the most serious issues is the “chicken-or-egg” problem—which comes first, the AHS highway lanes or the AHS-equipped vehicles? Minimum AHS vehicle penetration for a particular corridor or highway segment is reached when, after conversion of one of the existing highway lanes to AHS, the number of AHS lane users equals the number of manual users of the lane before conversion. It was estimated that this minimum AHS vehicle penetration ranged from 5 to 30% of the total vehicle population depending on many factors such as number of lanes already existing in the corridor, frequency of entry and exit lanes, and average trip distance.

Electronic control system and collision avoidance system for an electric cart

Abstract: An electronic control system including a collision avoidance system is for use on an electric cart, such as used for shopping, wherein the electronic control system includes a databus board for expanding user options on the electric cart. The collision avoidance system includes sensors which detect the presence of objects in the path of the moving cart and the system acts to stop the cart when the objects are detected. Additional user options of the electronic control system are an anti-theft system for deterring cart theft and vandalism and a voice module for playing recorded messages to the cart operator.

Development of rear-end collision avoidance system

Abstract: RCAS (rear-end collision avoidance system) has been developed as a system of ASV (advanced safety vehicle). It is a driver assist system to avoid the rear-end collision by informing the distance headway. It also has automatic braking function in case of emergency and distance warning function to the trailing vehicle. This paper describes the outline of RCAS, techniques about the preceding vehicle recognition and collision potential hazard evaluation. And experimental results about distance headway warning and collision avoidance by automatic braking are reported.

A collision avoidance system

Abstract: A collision avoidance system for a vehicle, the system including: transmitting means for transmitting a signal; receiving means for receiving the transmitted signal when reflected by an object; and processing means for calculating the distance between the vehicle and object, wherein the processing means is adapted to operate actuating means when the calculated distance is less than a predetermined distance

Development of performance specifications for collision avoidance systems for lane change crashes. task 6 interim report: testbed systems design and associated facilities

Abstract: This report documents the design of an on-road testbed vehicle. The purposes of this testbed are twofold: 1) Establish a foundation for estimating lane change collision avoidance effectiveness, and 2) Provide information pertinent to setting performance specifications for a lane change collision avoidance system (CAS). This design is expected to be a significant advance over other current methods that require manually viewing information stored on videotape. The key subsystems that make the testbed unique are its scanning laser and eye tracker. The scanning laser is mounted to the right rear corner of the car and scans a full 360 deg at 10 Hz. A prototype version of this laser has been tested and shown to be effective in providing range data on cars out to a range in excess of 200 ft. This sensor provides digital measurements of ground reference data in addition to target inputs for a prototype CAS. The eye tracker is able to track driver gaze direction at an update rate of 60 Hz. Using a lightweight, relatively unobtrusive headband, the eye tracker accommodates full rotation of the head, from left blind spot to right blind spot. The eye tracker is thus able to provide a continuous digital record of gaze direction as the driver executes a lane change maneuver. Post-processing of the digital data taken in on-road tests reveals what, if any, effect the introduction of a CAS has on the driver's behavior.

Impact of Intent-Based Maneuver Constraints on Alert Rates

Abstract: In the ultimate Free Flight environment, aircraft will experience restrictions on their flight paths only when such restrictions are required to preserve safe separation. The frequency with which s...

The virtual bumper: a control based collision avoidance system for highway vehicles

Abstract: This report summarizes research on a new collision avoidance strategy, the virtual bumper. The research involves development and simulation testing of the virtual bumper, a two-dimensional control strategy that provides steering, throttle, and braking actuation to maneuver a vehicle in a dynamic environment with the goal of avoiding obstacles and other vehicles. The concept applies to both normal and emergency driving conditions. Under all circumstances, the virtual bumper incorporates vehicle dynamic limits to ensure that the control commands are within safe levels. The virtual bumper will attempt to avoid a collision and will, at least, minimize the magnitude of an unavoidable collision. To test the functionality of the virtual bumper, researchers evaluated several driving scenarios. The scenarios consider both normal driving situations and emergency driving conditions. The normal driving scenarios demonstrated that the control algorithm operates the vehicle similar to the way a human would. This is important because a comfortable and predictable (i.e., intuitive) system response is required for achieving driver acceptance. The emergency scenarios demonstrated that the strategy is capable of reacting appropriately while maintaining safe acceleration/deceleration levels for the vehicle. This evaluation showed that the virtual bumper can provide safe vehicle control for a broad range of driving situations.

Beating blind spots : variable message signs have a valuable part to play in preventing collisions at a notorious accident black spot in the uk

Abstract: This article describes a type of collision avoidance system which has been developed in conjunction with variable message signs and embedded loop vehicle detectors. The loop detectors enable the calculation of vehicle speed and length, and this information is then incorporated into the warning messages displayed by the variable message signs. Application of the system at a particular highway location, notorious for accidents, is discussed.

Driver preferences for visual and auditory collision warning alerts

Abstract: Collision warning systems offer the public the opportunity to travel more safely and with less stress by integrating sensor technologies, software and a driver interface to warn drivers of potential collisions. While there have been several trials of individual collision warning systems, there is a general lack of studies focused on the systematic testing of collision warning systems for driver acceptance and performance. This paper describes tests of 50 alerts that were developed as candidates for an advanced collision alert system. The research was part of a larger study, the Advanced Collision Avoidance System Project, funded through the U.S. Technology Reinvestment Program (TRP) to develop and test a collision avoidance system for vehicles. The project was managed through the National Highway Traffic Safety Administration (NHTSA) of the U.S. Department of Transportation. Any functioning collision warning system needs a mechanism to advise the driver of the nature of potential collisions while the vehicle moves along the road. Generically, such a device is referred to as a driver-vehicle interface because it is the mechanism by which the on-board vehicle system conveys to the driver useful information upon which the driver must react. In addition to the physical platform which makes up the driver-vehicle interface, there are a host of design issues which evolve about the content of the interface and the modality of presentation (e.g. auditory or visual). The content of the interface is referred to in this report as the "alert". Alerts to be tested include text, icons, auditory words and tones and combinations of the above. For the covering abstract, see IRRD 490001.

Vehicular collision avoidance system

Abstract: In order to prevent an own vehicle from colliding with an other vehicle, the own vehicle carries a stereogrammetric rangefinder 3, 4, 11. Repeated ranges to the other vehicle give its relative speed, and, in combination with the own vehicle's speed, its absolute speed and hence deceleration. The speeds and deceleration are used to determine a safe distance; if the measured range is less than this, warning buzzer 7 sounds. If the deceleration exceeds a threshold, the safe distance is increased.

Collision avoidance system based on a multisensor set-up

Abstract: This article presents a multisensor system developed in order to avoid road crashes. The system deals with data issued from sensors placed on an experimental vehicle driving in a real environment. The aim of this project is to design a hardware and software system which can help to avoid accidents. The integration of the multisensor system aims at fusing different information sources in order to take safer decisions. A lot of heterogeneous and asynchronous data must be taken into consideration for the study and achievement of an on-board driving aid. This information given by different sensors passes through a Controller Area Network. The sensors limitations are taken into account and the system takes advantage of each sensor as well as possible. The sensor set allows the reconstruction of a local road map as accurately as possible. (A) For the covering abstract, see IRRD 490001.

Mitsubishi advanced safety vehicle (asv)

Abstract: The 1st Advanced Safety Vehicle (ASV) project, advocated by Japan's Ministry of Transport, was carried out from 1991 to March 1996 to promote developing safety measures for the 21st century mainly by intellectualizing vehicles. This paper introduces the main features of Mitsubishi's Active Safety ASV and Passive Safety ASV which employ many state-of-the-art technologies to support the driver under various traffic situations. The Active Safety ASV is equipped with so-called "Multi-Eye System" which consists of several kinds of sensors to detect surrounding traffic situations, and "Friendly Man-Machine Interface" which consists of sophisticated indicators and warning systems. The collision avoidance system assesses the situational risk and warns the driver or performs an automatic collision avoidance if necessary. Some ASV technologies have been adopted in recent Mitsubishi's production models, and Mitsubishi Motors, including its truck and bus division, has already moved on to the 2nd ASV plan. For the covering abstract, see IRRD 490001.

Cooperatively controlled collision avoidance

Abstract: The cooperative control concept can be applied to the vehicle controlled collision avoidance system. It can be transformed from the driver assistant controller and be extended to the future IVHS applications. In this paper, the system architecture of the cooperatively controlled collision avoidance system and advantage over independently controlled vehicles will be discussed.

On a computer controlled collision avoidance

Abstract: Since the use of shipborne computer controlled navigation systems has increased considerably during recent years, the work presents a concept for a new computerized collision avoidance system. The proposed system is based on the most modern achievements of optimal control theory associated with proper numerical methods. The worked out algorithms form the basis for the programming of a digital control device (computer) which constitutes its central unit. Systems of this type are able to control ship motion in an intelligent way i.e. steering her along a curvilinear trajectory as to avoid collision with other moving or stationary objects in a safe and optimal way and to return back on the old track. Satisfactory simulation results prove that construction of a proper algorithm is quite possible and that an intelligent control system of this type is able (for some class of collision situations) to make ship's behavior superior to that of a human operator.