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The purpose of this paper is to discuss handling in the context of those operational variables and vehicle chassis considerations which are most significant in affecting the handling properties of light trucks. In discussing handling for normal driving the Cornering Compliance Concept is used to combine the most significant parameters in a simple lumped parameter model. Limit handling performance and the mechanics of rollover are discussed in the paper. It is observed that exposure to limit handling maneuvers is unlikely to occur in normal driving. The significance of vehicle handling properties to highway safety is an unknown at this time.

This paper discusses the techniques employed in the development of the 1975 Ford Econoline Van, Club Wagon, and Cutaway vehicles. The presentation highlights the key elements of engineering a new family of light trucks. A brief review of historical van and bus market trends and their role in determining new vehicle design objectives is included. Specific engineering subjects discussed are: ˙Body-on-frame structural design applied to van/bus/cutaway vehicles. ˙Development of an energy absorbing frame for these forward control trucks. ˙Engineering techniques applied to the resolution of vehicle shake problems. ˙Modifications to front and rear suspension for optimum ride, handling and tire wear. ˙Development of integrated climate control systems for van/bus vehicles. ˙The engineering of derivatives for body builder recreation vehicle markets.

Thirty-three airbag-equipped Mercury cars were crash tested at three different test laboratories in order to determine the repeatability of test results in the proposed FMVSS 208 procedure. Nine Hybrid-II crash dummies were used. There were significant inconsistencies in results from the three testing agencies; by comparison, the different dummies caused little or no difference in test results; there was a large component of test variability due to uncontrolled and generally unknown factors operating in each test crash.

Tire traction test data has shown empirically that peak skid number dry pavement traction performance of bias ply tires is inversely proportional to the dynamic instantaneous tire load and is a function of inflation pressure. A modification to classical braking theory, which assumes constant traction coefficients at the tire-road interface, is therefore required to obtain maximum theoretical unlocked wheel vehicle deceleration. Optimum brake proportioning between front and rear axles is dictated by the maximum braking force which, with respect to each axle, can be generated at the tire-road interface. The inclusion of peak traction coefficient normal load sensitivity significantly modifies classical theory and changes the selection of brake force balance required to attain maximum theoretical deceleration capability. The importance of the effects of tire traction load sensitivity on the requirements of FMVSS 105-75 is discussed in this paper.

The Ford approach to ESV development was to attempt to meet government Experimental Safety Vehicle Program objectives by modifying a production vehicle by the use of materials and manufacturing processes suitable for mass production, and thereby hold cost increases to a reasonable level. This objective has not been met. However, improvements in vehicle structural integrity were accomplished in the experimental vehicle, and valuable engineering information was obtained. The methods employed to achieve these improvements did not prove to be feasible for established mass production techniques. They were highly experimental in nature, prohibitive in cost, and resulted in a weight penalty of 32% over a current production Ford. The Ford ESV incorporates a special body-frame energy absorbing system designed to dissipate kinetic energy during a 50 mph barrier crash.

The use of a new tool for the evaluation of driver visibility requirements is described. The tool takes the form of a program written for an interactive computer graphics system. XYZ coordinates of window openings, visual obstructions, mirror systems and driver eye points are supplied as data. Polar coordinate line drawings are then generated on the graphics display simulating what a driver would see directly to the front and sides or indirectly to the rear through a rear view mirror. The program can be used to evaluate driver visibility in terms of forward and rearward visibility target areas in actual vehicles or in vehicle concepts (clay models, prototypes and car body drawings) which are sufficiently well developed to permit the specification of window coordinates.

A new method, which enlists the aid of a digital computer, has been perfected to quickly and accurately determine the performance of a proposed rearview mirror while still early in the design stage. Because of the Federal Motor Vehicle Safety Standards (FMVSS) require a minimum viewing performance for both inside and outside left rearview mirrors, and since a common method — by which an intended design can be judged for compliance — would benefit both the Industry and the Federal Government, this method and the appropriate computer programs are being made available to all interested groups. Use of the computer programs results in a tremendous time savings over any manual drafting technique. This paper is intended to serve as a design guide to be followed when packaging rearview mirrors. A general introduction on the subject of rear viewing is followed by a discussion of the approach to the problem of evaluating the performance of a rear viewing device.