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Unlike lithium chloride, chemical, and other surface-type elements, the Brady Array exhibits bulk effects conforming to the Poole-Frenkel law concerning bulk phenomena. Other types of sensors require agglomeration of water or moisture prior to measurement; in the array, measurements are accomplished at a discrete molecular level, resulting in extremely rapid response and recovery times (better than 150 ms). Stressed bonds within the structure initiate rapid recovery by purging the sensor when it is moved from higher to lower values of relative humidity. The sensing element is contained within a TO-5 type transistor housing, measuring only 10 mil in diameter and 100 mil in length. The array has been operated over temperature extremes ranging - 200 to +800°F without damage or loss of calibration. The technique employed in the array also lends itself to sensing of other gases, when constructed using techniques proprietary to Thunder Scientific Corp.

Research in the development of assistive devices (power brakes, power steering, automatic transmission, etc.) is geared to close the gap between the handicapped and the normal operator. This objective is accomplished by providing additional assistive devices that will not interfere with the normal operation of the vehicle, but will enable the disabled individual safely to operate the same vehicle. This is achieved by considering the anthropometric and biomechanical constraints of the impaired driver. The pistol-grip controller is discussed in detail. It is intended to control manipulation of the steering wheel, brakes, lights, horn, windshield wiper, windows, etc.

The use of relatively small catalytic converters containing alumina-supported platinum (Pt) and palladium (Pd) catalysts to control exhaust emissions of hydrocarbons (HC) and carbon monoxide (CO) was investigated in full-scale vehicle tests. Catalytic converters containing 70-80in3 of fresh catalyst were installed at two converter locations on the vehicle. Carburetion was richer than stoichiometric, with air-fuel ratios (A/F) comparable to those proposed for dual-catalyst systems containing an NOx reduction catalyst. The vehicle was equipped with exhaust manifold air injection. Homogeneous thermal reaction in the exhaust manifolds played a significant role in the overall control of HC and CO. Four Pt catalysts, three Pd catalysts, and one Pt-Pd catalyst were prepared and evaluated. Total metal loadings were varied 0.01-0.07 troy oz. Hydrocarbon conversion efficiencies varied 62-82%, measured over the 1975 cold-hot start weighted Federal Test Procedure.

Stringent emission standards have strongly affected the requirement for catalysts and catalytic converters. Since considerable emphasis is placed on cold-start performance, catalysts with lower density and higher oxidation activity at lower temperatures are required. Monolithic catalysts have been extensively evaluated in low-emission vehicles. This paper identifies the key phenomena associated with overtemperature and emission breakthrough problems in platinum monolithic converters.

The purpose of this paper is to elucidate and expand on the categorization of disabilities as they specifically relate to the driving task. The authors use the example of an amputee to derive the design parameters characteristic of a given disability. A lengthy table detailing the categories of amputation is included, and a discussion of the table in relation to driving an automobile is presented.

The particular difficulties encountered in designing fuel and ignition control in today's automobiles have led to consideration of electronic systems. These are totally dependent upon the transducers used to provide the information they require, and frequently the success of a given system depends upon the solution of some transducer problem. This paper discusses some of the alternative choices of input parameters to a control system intended to manage the fuel and ignition of an internal combustion engine. The requirements for, and designs for, transducers to measure throttle angle, crankshaft speed and position, air mass flow, engine component position, and exhaust quality are discussed.

An experimental study of a naturally aspirated, spark-ignited prechamber mounted in a CFR engine demonstrated that this system provides a marked improvement in lean-mixture combustion both before and after engine warm-up. In the system tested, a premixed fuel-air mixture containing five times the stoichiometric amount of fuel was supplied to the prechamber at a rate of 2% of the main chamber mixture flow. The fuel-rich flame issuing from the prechamber provided an ignition source capable of igniting main chamber mixtures much leaner than those normally ignitable by a standard spark plug. There are many advantages and disadvantages when comparing the standard CFR engine with the prechamber CFR engine. This paper goes on to explain the prechamber engine in detail and to compare it with the standard engine.

Most transducers offered commercially are suitable for laboratory, aerospace, or industrial process applications but do not meet additional, stringent automotive requirements. A need exists, both present and future, for various types of transducers in automotive powerplant control systems. Possible electronic systems and subsystems requiring transducers are discussed, and the types of transducers needed for these systems are described along with a discussion of a general set of specifications with respect to accuracy, reliability, and durability. Substantial transducer development is needed to enhance the advancement of certain automotive electronic systems. This paper points out these requirements to the electronics industry in an effort to encourage a mutual industry development that will advance the technology.

An investigation of the influence of surface roughness of lubricated rolling-sliding contact surfaces on pitting fatigue has been carried out. A significant increase in pitting resistance resulted from polishing the ground mating surfaces. When the roughness of the loading rollers (positive slip element) was reduced from 10-15 to 5-9 μin rms and that of the test specimen (negative slip element) from 10 to 2-3 μin rms, there was a gain of about 150% in load-carrying capacity before pitting occurred. The surface roughness of the loading roller appears to be the dominating factor. The degree of metallic contact and surface distress decreases when the roughness of the roller approaches the thickness of the oil film.

Some of the mobility problems faced by the spinal cord injury patient are presented in this paper. Existing automobile hand controls for the handicapped are discussed and current efforts at evaluation and standardization of this equipment are described. Design constraints are outlined for the development of new equipment to allow the more severely handicapped to drive.

A comprehensive scanning electron microscope(SEM) survey of the fracture surfaces of an aircraft main landing gear shock strut piston showed that improper shot peening contributed to the initiation of the anamolous fatigue failure. SEM photographs of the suspect-origin regions and the surrounding areas were analyzed. The photographs are presented, along with a detailed description of the regions observed. Failure mechanism is discussed, and causes of fracture origin explored.

An analysis of oil pumpability reveals that engine oil pumping failures may occur because either the oil cannot flow under its own head to the oil screen inlet, or the oil is too viscous to flow through the screen and inlet tube fast enough to satisfy pump demands. To determine which factor is controlling, the behavior of commercial, multigraded oils was observed visually at temperatures from -40 to 0°F (-40 to - 17.8°C) in a laboratory oil pumpability test apparatus. Test results revealed that pumping failures occur by the first alternative: a hole is formed in the oil, and the surrounding oil is unable to flow into the hole fast enough to satisfy the pump. Of 14 oils tested, 7 failed to be pumped because of air binding or cavitation which developed in this manner. A model, which explains these failures in terms of yield point considerations and the low shear apparent viscosity of the oils, is proposed.

The inability of certain crankcase oils to flow and lubricate an engine at low temperature and the lack of a suitable bench test to predict this characteristic are of current concern to engine builders and oil formulators. Two critical areas of oil flow at very low temperatures have been recognized by SAE and ASTM subcommittees. These are: the ability of an oil to flow to the oil screen of an engine fast enough to prevent “air binding,” and its ability to be drawn through the oil screen and pump inlet tubing without causing “pump cavitation.” The interrelation between these two factors is discussed and some engine pumpability data are presented which illustrate how one of these factors may affect the other. Descriptions of four new bench tests are presented along with data to show their ability to predict the low-temperature pumpability properties of crankcase oils.

This paper describes a diffused semiconductor strain gage pressure transducer designed for use as a manifold vacuum sensor in electronic ignition and electronic fuel injection systems. The design philosophy, construction, and the calibration techniques used to enable the subject transducer to perform accurately over a broad range of environments and maintain this performance for thousands of miles without periodic recalibration, are discussed.

An improved theoretical model that predicts the nitric oxide concentration in the exhaust of a spark-ignition engine has been evaluated over a wide range of fuel-air ratios, percentage of exhaust gas recycled, and engine speed. Experiments were carried out in a standard CFR single-cylinder engine. Comparison of the measured and calculated exhaust nitric oxide concentrations shows good agreement over all operating conditions. It is shown that in lean mixtures, nitric oxide concentrations freeze early in the expansion stroke. For rich mixtures, freezing occurs later after all the charge has been burned and substantial nitric oxide decomposition takes place. In addition, effects of exhaust gas recirculation on flame speed, ignition delay, and cycle-to-cycle pressure variations were evaluated. A simple model relating cycle-to-cycle variations with changes in ignition delay is presented.

This paper reviews the automobile development process, highlighting improvements that have been made. New model development is described first, followed by discussions of proving grounds testing and test facilities. Some of the product changes which have resulted from these processes are enumerated in the areas of corrosion protection, lubrication, electronics, customer comfort and convenience, tires and brakes, and safety and security. Finally, a product comparison is presented of a 1958 model automobile versus a 1973 model of a comparable automobile.

The importance of high shear conditions in automotive lubrication is discussed with respect to the influence on lubricant rheological properties. The distribution of shearing effects in lubricated components is also discussed. Two methods of simulating high shear conditions-an elastohydrodynamic lubrication simulator and a capillary viscometer-are presented, along with some data obtained from them on polymer-containing oils.

Several sets of both police-reported and in-depth traffic accident data are queried with respect to the involvement of vehicle malfunctions or defects in accident causation. It is concluded that accident-causing defects are inconsistently reported, are often attributable to the lack of appropriate maintenance practices, and are evidently not being corrected by present motor vehicle inspection systems. Although vehicle malfunctions are less frequently identified as accident causes than either human or environmental factors, they are noted often enough to be considered a problem. It is suggested that the automotive engineer has already built into the vehicle many detection systems which serve notice to the vehicle owner/operator that a component needs attention. Finally, it is suggested that further efforts in this direction may supplement state authorized periodic inspection programs in minimizing the incidence of vehicle defects in accidents.

A program is underway at the DOT/Transportation Systems Center to study the nondestructive detection of defects in tires, and to determine the relationship between these defects and tire failure. Ultrasonics, x-ray, infrared, holography, and other techniques are being used to determine their effectiveness as well as their limitations in this task. This paper describes the use and modification of the equipment for nondestructive inspection of new and retreaded tires. It also describes the use of a computer data bank for data collection, storage, and retrieval in the correlation of results.

An experimental technique has been developed to measure the minimum oil film thickness of dynamically loaded journal bearings. Inductive transducers were used to measure the motion of the journal within the bearing clearance and with this information the relative oil film thickness was determined. The measured film thickness correlated closely with analytically predicted values for five base oils. However, tests on four oils which met the SAE multiviscosity engine oil classification (three SAE 10W-30 and one SAE 10W-40) showed that the low shear rate viscosity of these oils could not be used to predict the bearing oil film thickness developed by these oils.