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The function of all technical reporting can be stated in a single word -- communication. A technical report fails in its purpose precisely in the degree that it fails to communicate. It is very important that engineers, scientists, and technicians know how to write clear, concise and understandable reports -- reports that communicate! The individual who develops this ability will benefit himself, his company, and his profession. This paper shows some of the important steps that lead to writing technical reports that communicate.

Automobile dynamics related to closed-loop control by the driver are presented. This includes developing the equations of motion; linearizing the 4 deg of freedom set for roll angle, lateral velocity, yaw rate, and axial velocity; and deriving the steer angle transfer functions. A compendium of dynamic data for United States style automobiles is given. Example transfer functions for a typical sedan, circa 1965, are computed. Literal approximate factors for the lateral transfer functions in both 2 and 3 deg of freedom are derived and tabulated.

A computer program has been developed which can faithfully reproduce certain viscous flow phenomena which up to now have defied analysis. The foundation of this program is rooted in a better understanding of the boundary layer development over a two-dimensional body. The use of an existing laminar boundary layer theory, in conjunction with an improved transition criteria and turbulent boundary layer theory, has led to a capability of predicting the complete boundary layer development on an airfoil section given only the pressure distribution about the body. The theoretical trailing-edge values of the momentum thickness, θ, and shape factor, H, are used in the Squire and Young profile drag formula to calculate the section drag coefficient. The lift coefficient, obtained from integrating the pressures used in the boundary layer analysis, are plotted against the section drag coefficient to obtain the airfoil drag polar.

This paper presents an analysis of a car following model of general form: ẍn + 1 = A (ẋn -ẋn + 1)/(xn - xn + 1)m, where A and m are constants, xn + 1 is the position of the following car, xn the position of the followed car, ẋn + 1 and ẋn the corresponding velocities, and ẍn + 1 the acceleration of the following car. Several specific values of m are considered and their correlation with various traffic flow diagrams is established. Traffic flow in which all drivers, in line of vehicles, maintain a certain minimum safe distance is represented by the case, m = 0. The case, m = l, is shown to lead to a velocity-concentration curve due to Greenberg. The case, m = 2, is correlated with the rate of change of the visual perceptual angle of the follower and is shown to lead to Greenshields' velocity-concentration curve. Finally, the implications of the case when → ∞ are explored.

In the development of an operational traffic control system it was necessary to depend heavily on empirical data of traffic performance measurements. The major problem in operating a transportation system is traffic overloading demands at peak periods. The Expressway Surveillance Project was formed to improve the efficiency of the highway system through the application of electronic automation and traffic engineering to the problem of traffic congestion. By providing a means for quick response in case of accidents and fast removal of hindrances, volume capability of freeways were effectively increased during peak periods. The use of ramp metering controls effected a reduction in delay, afforded safer merging characteristics, and reduced freeway accidents. Since there is a limit to the volume capacity of a highway system there may come a time when access to the whole system may be controlled and additional persons may have to utilize other modes of transportation.

A detailed, human factor based simulation has been developed for following, overtaking, and merging on freeways. Simulation parameters were chosen to provide correspondence with human factor data and with several types of macroscopic and microscopic traffic measurements. Simulation results provide some guides to the vulnerabilities of driver types, and to the accident potentials of frequently occurring situations.

This paper outlines an approach to highway transportation research which considers the interrelationship of the major subsystems. It describes the framework, the variables, surveillance techniques, and new vehicle instrumentation. A model is described which serves as the basis for field testing and subsequent mathematical analyses. Surveillance systems including instrumented vehicles, ground, aerial, and space platforms are required as components of a real-time system. A research project, designed to evaluate driver stress, is discussed and sample computer data are shown.

The described vehicle traffic simulator is designed to facilitate analysis of traffic flow and to experiment with postulated traffic control systems. It offers users a large amount of flexibility in specifying network, intersection, vehicle, and control parameters. The logical flow of vehicles, as well as much of the control system, is preprogrammed. Vehicles varying in size may change lanes, turn, change velocity (including reaction and acceleration delays), and merge. Inputs may be varied, turns may be eliminated, and vehicles may be routed through the network. The user supplies the geometrical characteristics and input information unique to his particular network in data cards for the program. Some applications to real traffic networks (including a validation procedure) and some simple control experiments are discussed.

Two digital computer simulation models of traffic operation and control have been developed -- a microscopic single, signalized intersection model, and a macroscopic signalized intersection network model. The paper describes the general features of the simulation models, presents summary data pertaining to the validity of the models, and briefly reviews research results from studies of traffic signal system operation made with the models.

While a number of important attempts have been made to describe characteristics of an intersection purely in mathematical terms, the most fruitful research from a practical standpoint has utilized simulation. This paper reports the results of research in which a four-way stop intersection was simulated on a digital computer. Inputs to the program were based on field studies at three intersections in metropolitan Atlanta using mathematical models and Monte Carlo techniques. Field data were taken with the aid of a spring wound Esterline-Angus 20-pen event recorder and time lapse movies. The simulation model was used to study the effectiveness of the four-way stop at various approach volumes and turning movement combinations. Results of experiments conducted on the simulation model are given by graphs showing the relationship between traffic volumes and average delay, per cent delayed, and average queue length.

Vehicle traffic congestion is one of the serious problems facing municipal administrators. The search for increased efficiency has led to the development of traffic engineering as a science. The digital computer as a traffic engineer's instrument is relatively new, but appears to be a natural successor to analog systems, which have in turn sprung from fixed time systems and noncoordinated devices. Today's computer systems are the first to link all the elements of a closed-loop automatic control system; namely, information gathering, decision-making, execution, verification, and evaluation. In particular, the system at San Jose has shown that a computer system can be readily adapted to handle different control techniques, and give almost immediate feedback in concrete terms. A system of measuring stops and delay, developed at San Jose, can be used to evaluate traffic in both a microscopic and macroscopic sense.

The image of a large corporation in today’s technical world is, in many instances, dependent upon its interest in the innovative process and adaptability to change. Air pollution poses a serious threat to this country. In an effort to implement recommendations for the control of automotive air pollution, the more important findings of a government study group (fully reported in “The Automobile and Air Pollution: A Program for Progress”) are summarized. The development of effective means to infuse new ideas into the automotive industry is discussed.

An integrated circuit regulator for automotive alternator systems has been developed. It may be used either as a separately mounted unit or incorporated within the alternator. Consideration is given to the choice of micro-circuit, the type of transistors, and the method of substrate assembly. The design features and operation of the circuit are discussed.

This paper presents a new concept and technique for solving the problems associated with the prediction and control of flight component failures which are attributed to contamination of the power transmission fluid in the servo actuating subsystem. Basically this technique assumes that these failures are probabilistic. Mathematical models are then established and comparisons made between calculated and measured values of contamination in a system to determine the degree of acceptability of the fluid.

The automotive gasoline engine has been under heavy attack as a source of air pollution, and is now the subject of a very large program of research and development to reduce its undesirable vehicle emissions. The quantity of emissions that can reasonably be tolerated in different areas of the U.S. is presently unknown because of lack of information concerning air movements and air quality standards for man and plants. It is important that this information be made available as quickly as possible because the cost of emission controls of all types will rise rapidly. With rapidly rising costs for air pollution control from all sources, cost-value analyses are urgently needed for economy. Major reductions of the undesirable exhaust emissions of present powerplant systems have been made during the last few years and will continue to be accomplished, under the impetus of air pollution requirements and regulations.

The new SAE J992 establishes minimum service brake system performance requirements and specifically pertains to vehicle stopping ability, pedal force requirements, and brake stability of new vehicles. Testing for SAE J992 includes procedures that were taken from applicable sections of the truck and brake system road test code, SAE J786 dated 1962. This paper compares SAE J992 and J786 in the areas of test instrumentation, preburnish check, burnish, water recovery, and efffectiveness requirements. Although SAE J992 is briefer than previous test procedures, it is a valid determination of minimum stopping ability, a check on the initial fade due to heat, and a measurement of the water recovery characteristic. The minimum performance values specified are quite stringent for all types of trucks and buses.

The revised Passenger Car Road Test Code, SAE J843a, provides a test procedure of improved reproducibility and a high degree of severity. The new report, SAE J937, performance requirements, are stringent and have contributed to the up-grading of passenger car brake systems and individual components.

The author reviews work underway to expand current brake test standards. Initially he discusses the Pennsylvania procedure for testing original equipment and aftermarket brake linings. Although these tests are similar to SAE tests, current SAE procedures have to be expanded so they can be used for component approval, other than linings, in order to realize full capabilities of existing brake test specifications. Subcommittee 7 has assigned working groups to develop special procedures in the areas of partial system performance, passenger car durability, brake structural integrity test, truck-trailer performance test, and car-trailer performance test. The work being done in these areas is reviewed. It is obvious that constant up-dating of specifications is a necessity in order to reflect the state-of-the-art as accurately as possible.

The Allison 250 turboprop program is reviewed including engine characteristics, the development program, FAA certification, and development to higher power ratings. Market and installation programs are reviewed including general aircraft turbine engine trends, turbine engine market potential, and a discussion of the justification and merits of small turboprop aircraft. Various 250 turboprop installations are discussed.

Constant frequency a-c electrical equipment, consisting of a hydraulic constant speed drive powering an a-c generator, is now available for consideration on business aircraft. This system can provide significant weight savings over other types of electrical systems and provides the same high reliability and good growth potential that has been realized on larger military and commercial aircraft since 1946. The weight savings that can be attained is particularly appealing when the aircraft includes an auxiliary power unit (APU) that can be used to provide power for pneumatic or hydraulic main engine starting. This eliminates the need for the heavy d-c starter/generator and results in lower overall aircraft weight.