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A general discussion of crash sensor requirements is provided, with emphasis on the advantages of long inflation times. An explanation of the basic radar system is offered, and various designs, broken down both by antenna configuration and carrier modulation, are investigated. After careful study it is found that all radar sensors suffer from the same inadequacy-the inability to correctly classify obstacles into hazardous and nonhazardous categories. Several approaches to solving this problem are discussed. The conclusion is reached that radar crash sensors will be unavailable for MY 1976 air cushion requirements.

This paper describes a radar sensor which is being developed as an adequate sensor for an inflatable occupant restraint system. The important characteristic of this radar sensor is that an optimum highly sensitive sensing zone is formed by the combination of two transmission antennas and two reception antennas in order to improve the collision judgment accuracy, minimize the difference of precollision time for various obstacles, and suppress the received signal level due to rain and snow, etc.

Consumers' acceptance of and attitude toward a passive three-point belt system have been studied and evaluated in a personal interview investigation of 325 people. These participants were provided with the opportunity to try out the belt system in two demonstration cars-2-door and 4-door sedans. The method of selecting the respondents complied very well with the requirements of public representation. The results of the inquiry are presented in the full survey as related to driver, passenger, age, sex, etc. The main question in the study-the convenience when entering or leaving the demonstration car-was very positively judged. The most frequent opinion on a 7-point evaluation scale was as high as 7 (most positive); the average value of 6.2-5.9 was given for wide- and half-open doors, respectively.

Impositions placed on vehicle occupants by safety belts and safety belt use are substantial and will increase as systems to encourage or force belt usage are incorporated. By comparison, the known impositions of air bags are minor, but to these must be added other requirements, the extent of which are not yet well-known. Substantial fleet testing of air bags will clarify most of these inconveniences. Automobile manufacturers and the National Highway Traffic Safety Administration have failed to generate public support for the air bag. Lack of consumer support will continue unless greater resources are allocated to equip fleet vehicles with air bag systems so that a reliable record of air-bag efficacy can be compiled.

Crash sensor interfacing with the automobile must be approached from the occupant protection standpoint. Generation of the crash pulse, which determines occupant response, is affected by complex vehicle variables that often preclude discrimination from noncrash signals. Synthesis of the design solution is approached on a systems basis to match sensor capability to vehicle variables. Reliability is provided for with appropriate design of experiments and statistical analysis.

A mathematical simulation of the operation of a compressed-gas airbag system is developed. A system was built and tested, and the analysis is evaluated on the basis of these tests. Included in the study are nonideal gas effects, manifold and diffuser effects, bag stretch, bag leakage, and overpressurization of the passenger compartment. Interaction between a single rigid object and the bag is also considered. A correlation between bag pressure and the force it generates is obtained. This allows the development of an analytic model for determining the motion of a single rigid mass interacting with a dynamically inflating airbag mounted in a moving vehicle. An application of the model to study rebound of the occupant from the airbag is presented.

The air bag is ready and installation in front seat positions is essential at the earliest possible date. There has been almost a conspiracy of silence and a supression of favorable data-thus the media and through it the public are almost completely uninformed, or even worse, misinformed about air bags. An informed public will accept and should demand an air bag system. Minimal utilization of active restraints (lap and shoulder belts) mandates passive restraints (air bags). This group (S.A.E.) has a duty to cause a speed-up in the present rate of availability of air bags. The ultimate savings in lives and reduction in serious injuries as well as automobile insurance costs will be gratifying and substantial.

In this paper you will find problems posed by threatened lawsuits arising out of potential defects in passive restraint systems. For many years, it was recognized that the manufacturer of an automobile was liable for defects in manufacture or design which produce injuries. Now the question is should part of the cost of claims and verdicts be shifted to the government-this might make the government more responsive to the feasibility of adopting particular safety systems.

Lap-shoulder belts became standard with very little, very inneffective explanation of why they should be used. National effort is needed to persuade all to use them, and auto industry to improve them, and see the effect of buzzers and interlocks before mandating airbags or equivalent. This paper looks at the past history of restraints, forecasts the future if airbags are to be mandated without explaining them. AAA of Michigan motorist survey shows strong dislike of airbags, a preference for seatbelt-shoulder harness if choice must be made, a strong feeling that it is not the business of government to mandate airbag or seatbelt use. Question is raised about claims of number of lives that airbags will save. Are they too high?

Interest in fuel injection is spurred on by the promise of lower emissions. The problem of NOx will require better control of fuel metering to comply with the emission standards set by the federal government. Fuel injection and other basic engine changes can provide the emission levels by operating in a lean air/fuel (A/F) ratio to reduce NOx.

An External Combustion Engine (ECE) was designed, tested, and retrofitted to a 40 ft, 46-passenger city bus. The bus was tested and demonstrated comparable acceleration and lower external noise, odor, and air pollution emissions than a diesel bus. Presently, ECE bus fuel consumption is considerably higher than that of a diesel bus. It is shown in this paper how ECE fuel consumption can be improved with further development, although not to lower levels than the diesel. More time in service is needed to determine the ECE bus operating costs, which depend largely on the costs of powerplant maintenance.

The need for new mass transit vehicle alternatives has been spurred by the growing concern in our cities over photochemical smog, noise, smoke, odor, and transit system operating deficits, which are to a large degree the products of present rolling equipment. A project planned in conjunction with the San Francisco Municipal Railway is intended to demonstrate a practical kinetic energy (flywheel) propulsion system providing optimized electric transit with route flexibility and increased quality of service. The dual-mode trolley coaches used for the demonstration will be capable of providing scaled operational data that can be extrapolated to new classes of ecologically and socially acceptable vehicles.

In order to determine the operational characteristics of human pedal force, a driving simulator consisting of a driver's seat, pedals, analog computer, double gun synchroscope, etc., was developed. The driver was asked to guide the spot representing the controlled variable using the spot as a target. A simple transfer function to match the test results was derived and the effect of parameters on the constants in this function was analyzed. This experiment established that a pedal force of 200 daN seemed best for control.

After using an analog computer and a mechanical substitution system to determine if the project was possible, a remote control ground vehicle was designed and constructed which would follow a predetermined course at a given speed to test the handling characteristics of vehicles and to conduct crash tests safely. The vehicle is guided visually via onboard TV. Data are fed back by 6-channel FM, while 4-channel FM serves to transmit commands to servo motors in the unmanned vehicle. Except for a cathode ray tube, all onboard control instrumentation is crashproof, and a self-contained power source provides for fail-safe braking.

Three investigations are reported which clarify the mechanism of exhaust hydrocarbon (HC) emission and suggest new ways to reduce these emissions from reciprocating, 4-stroke, spark-ignition engines. The work was carried out on an engine using the sealed ring-orifice (SR-O) piston, which effectively eliminates exhaust HC emission caused by the piston-bore-ring crevice. This reduces HC emission substantially, making other effects more apparent. In the first investigation, exhaust HC concentrations were unchanged when the engine was run first with oil and then water in the crankcase. This means that oil did not contribute to exhaust HC emission in the SR-O engine. In the second investigation, small patches of simulated deposit attached at different locations in the combustion chamber caused exhaust HC concentration increases which varied by a factor of 10, depending on deposit location.

The deterioration of secondary ignition wiring life on today's internal combustion gasoline engine has created many maintenance problems in the field. The mandatory use of TVRS (resistance wire) has amplified these problems and made them more difficult to solve. The solution does not lie solely with wire design-engine application, engine design, and component selection and location are also important factors. THE LIFE SPAN of the secondary wiring used on gasoline automotive engines dropped dramatically with the introduction of resistance-type wire which is commonly referred to as TVRS wire. The TVRS wire was introduced to suppress ignition interference in accordance with SAE specifications, and to meet the requirement of Public Law 200 passed in October 1951. The TVRS wire was also intended to reduce spark plug electrode erosion. While both of these missions were accomplished, in most cases the wire had a very short life.

A review of the long-standing highway truck ride problem and conventional solutions emphasizes an increased usage of suspension seats to isolate the driver from predominant cab vibration. A novel new suspension seat (Hydra-Flex) features an articulated linkage which conforms to similar kinematics as natural motion of the human body. Further, this linkage inherently provides an action which cancels the characteristic back-slapping motion of truck cabs. Numerous inherent advantages over conventional designs of suspension seats are disclosed, and these features are attributed to the “bionics” principle which is involved.

Increasing underhood temperatures and decreasing availability of vacuum, indirectly caused by more stringent safety and emission control regulations, brings the possibility of central hydraulic systems closer. However, as the central system fully evolves, equipment manufacturers indicate that they expect a transition step, where the same fluid will be used in both the power steering and power braking systems. With the expected demands on fluids to be used in such systems increasing, Dow Corning has initiated the development of a silicone candidate, based on the most readily available silicone fluid, dimethylpolysiloxane. The recent advances in lubrication technology, information on compatibility with presently used materials, and the inherent physical and chemical properties which allow a silicone fluid to be a serious candidate for such usage, are presented.