Showing papers on "Collision avoidance published in 1976"

Proximity warning unit for vehicles - is capable of automatic collision avoidance using required deceleration threshold and controlled braking

Abstract: A proximity warning unit for vehicles has measurement and evaluation devices for vehicle speed, distance from defined vehicles or obstacles, and approach speed of other vehicles or obstacles. It is designed to present information to the driver enabling him to determine his need for intervention and to be suitable for automatic collision avoidance. The measured parameters are evaluated to produce a braking a deceleration requirement for collision avoidance and maintenance of separation. When the required deceleration exceeds a threshold which is preferably adjustable braking is automatically applied to restore tolerable proximity.

Communication system and method

Abstract: An aircraft collision avoidance system and method involves transmitting a stable reference frequency from a synchronous satellite to aircraft in a region being monitored. Each aircraft in the region receives the reference frequency and transmits a carrier, modulated with the received reference frequency, to other aircraft in a collision avoidance zone. At the other aircraft, an indication of impending collision is provided by measuring the rate of change of the carrier Doppler frequency shift received thereby from the first named aircraft. Sync pulses periodically modulate the reference frequency transmitted from the satellite for aircraft ranging and data control purposes. To limit the collision warning zone relative to each aircraft, the receiver thereof is deactivated at a predetermined time after each sync pulse is received from the satellite.

Collision Avoidance Systems and Optimal Turn Manœuvres

Abstract: The International Collision Regulations are explicit only with regard to manoeuvre responsibilities. The manoeuvres themselves have been the subject of a large number of technical papers and conferences particularly during the past 15 years. Nevertheless, although the use of shipboard radar systems has increased during this time, it is apparent from collision statistics and from the variety of published opinions and recommendations that the manoeuvre-specification problem is not considered as solved. In fact, in many cases, recommended turn manoeuvres can actually lead to a cooperative collision, when more realistic turn dynamics are assumed for the ships. The range of conflicting opinions, few of which are based on an analysis of ship manoeuvre dynamics, provides the motivation for the present study. The following work first determines on board radar accuracy requirements for collision avoidance, and then develops optimal collision avoidance manoeuvres as functions of the processed radar data. A major part of the study has been carried out under contract with the Maritime Administration of the United States.

Collision Avoidance Maneuvers for Ships

Abstract: The state-of-the-art in collision avoidance technology for ships consists of systems employing digital signal processors to compute ship tracks, target closest point of approach (CPA), and time-to-CPA. This information is presented to the ship's officers through CRT displays. This paper discusses the potential use of a shipboard digital computer to compute additional information from the radar video data and generate maneuver cues as an aid in collision avoidance. Techniques for generating collision avoidance maneuvers are related to ship maneuvering capability, as determined by its speed and turning characteristics. One example will be given to illustrate the relationship between CPA and miss distance for cooperative and uncooperative maneuvers, and another shows how dynamic maneuver charts can be used by a privileged vessel to decide when to take action to avoid a burdened vessel.

Collision Avoidance: The State of the Art and Some Recent Developments and Analyses

Abstract: There has been a long history of development of collision avoidance systems (CASs) starting in about 1945; but there has been little progress in terms of operational use. At first, most development concentrated on noncooperative radar systems but by about 1960 it was realized that radar, while feasible, could not offer an economically practicable solution. Efforts since then have been concentrated on cooperative systems, cooperative in the sense that any two aircraft involved in a threatening encounter must both be equipped with mutually compatible devices and there must be intercommunications of necessary data.

Analysis of a novel marine collision avoidance system

Abstract: This paper presents the results of the first phase of an ongoing effort to develop a novel marine collision avoidance system. The rapid increase in yearly losses due to marine collisions provides strong motivation for such a development. The equations which describe the relative dynamics between two encountering ships are used to determine the optimal maneuvers for avoiding the collision. These maneuvers minimize deviation off-course while achieving a safe miss distance. For the in extremis situation, the maneuver strategy changes to maximizing miss distance. Software requirements are determined to compensate for system measurements errors. An error analysis is conducted which determines the effect of measurement errors and encounter geometry variations on the system performance. The results are used to specify the requirements of an optimal marine collision avoidance system which serves as a standard against which all other commercially available collision avoidance systems can be compared.

Coordinated Vessel Maneuvering Using a Collision Avoidance Grid (CAG) System

Abstract: This paper is divided into two parts. Part I attempts to provide, in a general way, the operating atmosphere that exists on many a ship's bridge when maneuvering in traffic with some of the inherent problems and stresses that continue to prevail, even with the best equipment and training. Part II presents a proposed solution to these problems. Hopefully it will provide masters and watch officers with increased assurance that coordinated maneuvering with other vessels is possible. Using the Collision Avoidance Grid (CAG) System, in conjunction with radar and VHF radiotelephony, collision avoidance and positive control over the situation could be a rapidly achieved goal with little or no further training and no additional hardware.