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This paper presents the work of the SAE Brake NVH Standards Committee in developing a draft Low-Frequency Brake Noise Test Procedure. The goal of the procedure is to be able to accurately measure noise issues in the frequency range below 900 Hz using a conventional shaft brake noise dynamometer. The tests conducted while evaluating alternative test protocols will be discussed and examined in detail. The unique issues encountered in developing a suitable test procedure for low-frequency noise will be discussed, and the results of tests using both shaft brake dynamometers and chassis dynamometers will be described. The current draft procedure incorporating the knowledge gained from this development effort will be described in detail and conclusions as to its applicability will also be presented

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.

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.