Ride Index Structure and Development Methodology
This recommended practice defines methods for the measurement of periodic, random and transient whole-body vibration. It indicates the principal factors that combine to determine the degree to which a vibration exposure will cause discomfort. Informative appendices indicate the current state of knowledge and provide guidance on the possible effects of motion and vibration on discomfort. The frequency range considered is 0.5 Hz to 80 Hz. This recommended practice also defines the principles of preferred methods of mounting transducers for determining human exposure. This recommended practice is applicable to light passenger vehicles (e.g., passenger cars and light trucks). This recommended practice is applicable to motions transmitted to the human body as a whole through the buttocks, back and feet of a seated occupant, as well as through the hands of a driver.
This recommended practice offers a method for developing a ride performance index but does not specifically describe how to apply this index to assessment or comparison of specific vehicles.
This recommended practice indicates the current state of technology regarding the relationship between the human to vehicle interface vibration magnitude and human discomfort. The appendix is concerned with providing a uniform and convenient method of indicating the subjective severity of the motion and vibration but does not present limits. It is in no way related to quantifying health and safety aspects of motion and vibration for which an entirely different methodology would be needed. This methodology is intended to predict human sensitivity to motion and vibration for comparative purposes (i.e., condition A versus condition B) relative to a global (i.e., absolute) adjectival psychometric scale. See Appendix C for additional supporting rationale.