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There is a growing emphasis on the transfer of testing from the proving ground to the laboratory. The rapid evolution of test technology has been a key to making such transfers possible. This paper presents a description of the methods, including the critical data acquisition and the control parameter generation processes, developed to efficiently perform the move from the proving ground to the laboratory. Software tools are described that permit the user to collect vehicle control and response inputs on the road and convert these to test system control parameters. The process of collecting data is shown to be straight forward with a great deal of flexibility in terms of the type and number of channels to be collected. The conversion of these data to control parameters is described with examples. Parameters included in these studies include speeds, loads, vehicle inclination, accelerations, temperatures, torques, pedal positions, pedal force, time and distance.

A summary of the committee engaged in the development of a revised SAE J57 Truck Tire Noise Measurement Standard is presented. This discussion reviews the evaluations of the current standard, current and proposed international standards, and the key changes in the proposed revision to SAE J57. A major expansion to the scope of the current standard tackled by the committee was the effect of environmental conditions. The effects of road surface temperature, ambient air temperature, and wind are discussed. The measurement limitations and corrections implemented to address these factors are also described. Another key issue discussed is the effect of pavement surface. Cited references indicate that the effects of road surface variation can be greater than tire design differences. The committee developed a specification for a standardized surface to address this concern. Another improvement of the current standard is in the specification of tire operating conditions.

A description of the confirmation tests conducted by the Tire Noise Standards Committee for the revised J57, Truck Tire Noise Measurement Standard is presented. The goal of these tests was to determine the repeatability and variability associated with the procedures and ranges of parameters specified in this revision. Two sets of tires were tested over a range of measurement parameters. The parameters examined included tire type, ambient temperature, pavement surface temperature, coast-by speed, and trailer drawbar length. Finally, the total coast-by noise measurement variability according to this new procedure is estimated.

It is difficult to quantify the portion of coasting vehicle noise that is due to tire-pavement interaction alone. There are often contributions from aerodynamic noise of the vehicle, transmission whine, noise from suspension components, and other miscellaneous sources. The towed-trailer method used in the revised SAE J57 standard has been shown to be an effective means of isolating tire-pavement noise for truck tires. This paper reports the results of a test program conducted by SAE Tire Noise Standards Committee to evaluate the feasibility of towed-trailer coast-by testing of passenger and light truck tires. The results of tests conducted in April 1996 at the Ohio Transportation Research Center are described and they indicate that accurate measurements are possible for towed-trailer testing of passenger tires. It is shown that a key aspect of performing such a test is reducing the noise of the tow vehicle and that sufficient reduction is possible even for extremely quiet test tires.

As other vehicle systems have become more refined, more attention must be placed on brake NVH issues because they can cause a negative customer experience. From the laboratory to the road, the use of technology as well as further study by engineers is helping to lessen noise, judder, and vibration in cars. This book provides readers with a fundamental understanding of current practices for measuring and testing brake NVH. From coverage of basic definitions and concepts to in-depth analysis of on-road testing procedures, it will serve as a comprehensive reference guide for brake test technicians, test engineers, lab managers, and others who work on making brakes quieter, smoother, more refined, and more reliable. Readers will learn how to test for brake noise, what tools to use, and which recent standards and practices have led to the successful measurement of brake noise and vibration.