Showing papers on "Collision avoidance system published in 1979"

Automated road transportation system

Abstract: An automated transportation system for vehicular travel along a roadway is presented. The roadway can be any hard surface that contains an embedded metallic guiderail along its center. A proximity transducer (metal detector) installed under the vehicle, senses the metallic guiderail and sends steering commands to the vehicle's steering actuators to keep the vehicle moving in the center of the roadway directly over the guiderail. Transponders are embedded along the guiderail at selected points for automatic roadway identification, position determination and automatic speed, headway and route selection and automatic traffic control. The system also provides automatic branching and lane changing. The vehicle's control system includes sensors, signal processors, a microprocessor and various power actuators that are connected to the vehicle's steering, braking and accelerator systems. An on-board collision avoidance system using sonic or radar detection means is also provided. The vehicle can be programmed to automatically follow a pre-selected route by inserting route instructions into the microprocessor's memory where it can be retrieved and used any number of times. Magnetometer sensors are also embedded along the roadway to detect the presence and speed of all vehicles, thereby allowing ordinary, manually-controlled vehicles to use the same roadways as the automatically controlled vehicles for a mixed traffic flow. The guiderails and transponders can be embedded in essentially all existing streets and highways to provide an economical comprehensive fully automated road transportation system for private and commercial vehicles.

Collision avoidance using optical pattern growth rate

Abstract: A passive electro-optical collision avoidance system disposed within a moving vehicle for generating a collision avoidance signal. The system comprises a lens, image sensor and image processor wherein the image processor generates a collision avoidance signal in response to the size of the image and its rate of growth.

Modeling pilot response delays to beacon collision avoidance system commands

Abstract: : This report contains the results of an analysis of pilot response delays to collision avoidance commands displayed in the cockpit of a General Aviation Trainer (GAT) simulator. Data were obtained from previous tests conducted in the Beacon Collison Avoidance/GAT simulation at the National Aviation Facilities Experimental Center (NAFEC), Atlantic City, New Jersey. Subjects were general aviation pilots with a wide range of experience. Statistical curve fitting techniques are applied to response delay data. For fixed geometries, velocities, and aircraft response rates, the separation at the point of closest approach between aircraft responding to collision avoidance system (CAS) commands is inversely related to the length of pilot delay in responding to the CAS command. In experimental simulations used to measure that collision avoidance system effectiveness, the modeling of pilot response delays should be as realistic as is practicable. The results of this study provide a more realistic model than previously available. The Gamma distribution was the best distribution applicable to the queuing processes which are conceptually similar to the process that is generating the pilot response delay times. In terms of minimum error mean square, lack of bias, and uniformity of fit, the use of the Gamma distribution was found to be superior in approximating the empirical data. The recommendation to use the Gamma distribution in modeling pilot response delays in subsequent experimentation at NAFEC is made. (Author)

Air traffic control/full beacon collision avoidance system chicago simulation

Abstract: The purpose of this project was to investigate Air Traffic Control/Full Beacon Collision Avoidance System (ATC/BCAS) interaction in a high-density terminal area (featuring parallel instrument landing system (ILS) approaches) and to provide data for a comparative study between BCAS and other aircraft collision avoidance systems. The tests were conducted using the Air Traffic Control Simulation Facility (ATCSF) at NAFEC during March and April 1978. Analysis of the results indicated that the presence of BCAS had no adverse impact on the controllers or control procedures because of a very low interaction rate. Controllers were generally indifferent to the use of the BCAS during the simulation. A significant number of controllers desired the displaying of negative commands. Throughout the simulation, BCAS issued a high number of vertical speed limit (VSL) alerts; however, most of these were advisory in nature, having no effect on the aircraft flightpath. Certain changes in the BCAS logic are identified which would significantly reduce the VSL alert rate in the terminal area without derogation of safety. Recommendations are made to investigate further densensitization techniques and further development of a multi-aircraft resolution logic, and to perform additional real-time simulation to assess the effect of profile descent procedures on BCAS alert rates. (Author)

The Collision Avoidance Problem Requires a Mix of Partial Solutions

Abstract: The objective of collision avoidance is to assure the separation of aircraft during flight operations — to avoid the situation occurring where two or more aircraft could occupy the same point in airspace at the same time. The problem centres on how best to avoid such a spatial conflict—through ground‐derived data and air traffic control, by means of air‐derived data and pilot judgment, or by some combination of the two? In the quest for a solution, many kinds of systems have been studied and prototype hardware built and tested. Some provided only partial answers; some might meet the safety needs but create implementation difficulties; several have demonstrated the potential for world‐wide application. It is with the last group that we are concerned here. Any collision avoidance system (CAS) selected must be one that meets international requirements; this implies that protection can be offered to all aircraft, that the CAS is compatible with other existing systems and that costs would not be excessive. It ...

General Aviation Altimetry Errors for Collision Avoidance Systems

Abstract: Altimetry data is the prime component of monitoring reliable vertical separation of aircraft. This report compiles raw data gathered in flight tests conducted by the National Aviation Facilities Experimental Center of the Federal Aviation Administration. The compilation yields histograms of the errors in automatically reported altitude and errors in indicated altitude for general aviation aircraft in the U.S. The Federal Aviation Administration is currently considering two fully automatic collision avoidance systems: Automated Traffic Advisory and Resolution Service and Beacon-based Collision Avoidance System. Besides, the automatically reported altitude is being increasingly used in automation in the Air Traffic System, as exemplified by the current implementation of Conflict Alert in the en route air space. The magnitude of error in the transponder reported altitude affects the performance of any automated collision avoidance system. In this paper, the impact of the errors in reported altitude on expected alert rates for automatic collision avoidance systems are analysed. It is shown that acceptable collision avoidance service is feasible with a threshold criterion of vertical coincidence which is less than 500 ft. The quality of separation assurance protection from the general aviation population that an individual pilot may expect to receive is assessed as a function of the error in his own automatically reported altitude.

A Collision Avoidance System For Offshore Operations

Abstract: Greatly reduced probability of collision can be achieved through the use of an automated collision avoidance aid that permits rapid assessment of the situation and the determination of a safe, efficient maneuver. Types of operational collision avoidance systems are reviewed and compared. The mix of moving and fixed hazards is one problem that the system must handle. Tidal currents and winds can complicate the maneuvering solution. It is shown that the use of the predicted-area-of-danger (PAD) as a collision avoidance concept overcomes the problems peculiar to maneuvering in offshore gas and oil fields. Experience with the highly successful use of the PAD concept in the dense traffic of the English Channel is reviewed.