Showing papers on "Collision avoidance published in 1977"

Surveillance system for collision avoidance of aircrafts using radar beacon

Abstract: A collision avoidance system using on-board B-CAS equipment having an object to minimize interference with the ground SSR stations and to effect precise tracking or distance-altitude measurement when necessary. Normally passive surveillance is made to detect the presence of other aircraft in the B-CAS range. Active surveillance is added when required. In the active surveillance mode, initiated on locating an intruder aircraft, the power and interrogation signal are varied when the intruder aircraft becomes a threat aircraft to minimize interference with the ground SSR stations and aircraft outside the threat zone while maintaining accuracy of detection and tracking of the threat aircraft at a high level.

Collision avoidance at sea

Abstract: The problem of collision avoidance between surface ships may be examined from the perspective of either macro or micro collision avoidance. In macro collision avoidance the pilot of a ship would try for maintaining a given mileage separation between his own ship and others. Micro collision avoidance would be concerned with manoeuvres between ships of less than a given separation distance. Analysis of the two situations is different. In macro collision avoidance the other ships would often be maintaining constant speed and heading. Attention would be focused on keeping other ships out of an appropriate circle about the center of ones own ship. In micro collision avoidance other ships would in general be manoeuvering. The actual shape of the ships may be important in determining appropriate manoeuvers for own ship. In both macro and micro collision avoidance, qualitative game/control theory is useful for the determination of critical barriers and manoeuvre Results obtained this way for two ships are compared with some collision avoidance guidelines in actual use.

Initial collision avoidance algorithms for the beacon-based collision avoidance system

Abstract: This document describes a set of baseline collision avoidance algorithms which can be used as a point of departure for the development of final algorithms for the FAA's Beacon-based Collision Avoidance System (BCAS). The algorithms were structured to permit great flexibility in an experimental environment such as NAFEC. They incorporate a number of selectable options in the collision avoidance logic and in the display output. One option permits the selection of either a passive mode logic or an active mode logic. When the passive mode is selected, other options allow horizontal positive or negative commands to be used. In addition, the display of positive or negative commands can be selected or suppressed, and limit vertical rate commands can be selected for display independently of positive or negative commands. Two types of Intruder Position Data (IPD)-flashing IPD's and ordinary IPD's-can also be selected for display. The logic can drive three types of cockpit displays namely, an ACAS display, a baseline IPC display, and a general purpose Plan View Display (PVD). (Author)

Mm radar for highway collision avoidance

Abstract: An automatic/noncooperative radar braking system can both prevent and reduce the severity of accidents caused by inattentive or slow responding drivers. Tests indicate that discrimination against false targets is achievable by using a narrow antenna beam and limiting the range at which brakes are applied. This paper describes a 36 GHz radar possessing these desird paraeters which is size compatible with compact cars.

High density stable collisionless air traffic: computer simulations of traffic management in the itv system

Abstract: A system of air transport for the future is considered which envisages automatic operation of very large numbers of small vehicles. These craft will offer the traveller an airborne traverse at 200kt ground speed between air stations very close to the origin and destination of any journey. Computer simulations are presented to demonstrate the manner in which these vehicles can navigate, avoid collisions and preserve the stability of the resulting high density air traffic. The possibility that some of the features described might usefully be adapted to aid collision avoidance in existing air traffic is briefly discussed.

Human collision avoidance behavior as a function of visibility traffic density, electronic aiding and type of information displayed

Abstract: Licensed Captains of 80,000 DWT oil tankers were tested on a real time computerized simulator in order to evaluate their collision avoidance behavior in the open sea. Visibility, Traffic density, Navigational aid, and Type of information displayed were manipulated experimentally in order to assess the effects of these variables upon the human's performance in potential collision situations. The findings indicated that a computerized collision avoidance system greatly reduced the danger of collision in poor visibility and in high traffic density whereas the possibility of collision was increased using radar in poor visibility and high traffic density. Furthermore, it was found that a meaningful graphic display of information was responsible for the improved performance as compared to a visual alphanumeric display of target ship information.

Concerning the logical comparison of atc separation standard assessment models

Abstract: There exist many models for the determination or assessment of safe separation standards between aircraft flying under an air traffic control (ATC) system. Most models fall within the general categories of collision risk or collision avoidance. This paper presents a framework for the qualitative comparison of the logical structure of these several models. Thus the merits and appropriateness of the several models may be more critically evaluated, and better definition of model applicability made.