INSTRUMENTATION AND RESULTS OF RIDING-QUALITIES TESTS 260046
Ultimate successful measurement of riding-qualities is indicated by the design and construction of several new accelerometers. Experimental work with these new instruments has served to emphasize the desirable and the undesirable instrument-characteristics essential to accuracy, and thrown light upon some conflicting results heretofore obtained. One of the chief detriments to the development of accurate riding-qualities instruments has been the lack of satisfactory calibration. In the past, space-time curves have been used largely for calibration but, from the viewpoint of accuracy, these curves generally are acknowledged to be unsatisfactory.
An elaborate machine has been constructed which will produce simple harmonic-motion to a very high degree of accuracy. This machine provides a convenient and highly accurate method of calibrating accelerometers in terms of known fundamentals and, in combination with a method for inter-comparing different instruments under simulated road-conditions, it enables instrument calibration through the entire range of vibrations caused by road irregularities.
Measurements of axle accelerations and displacements indicate the need of concentration at this time on the correlation of the various factors entering into riding-qualities. However, a finite evaluation cannot be reached without investigation of physical and mental effects. The need for such an investigation is apparent.