BS ISO 14793:2011 pdf download.Road vehicles —- Heavy commercial vehicles and buses—Lateral transient response test methods.
4 Principle
IMPORTANT — The method of data analysis in the frequency domain is based on the assumption that the vehicle has a Imear response. Over the whole range of lateral acceleration this is unlikely to be the case, Ihe standard method of dealing with audi a situation being to restrict the range of the input so that linear behaviour can be assumed and, if necessary, to pedomi more than one test at different ranges of inputs which together, cover the total range of interest
The objective of these tests is to determine the transient response of a vehicle. Characteristic values and functions of both linear and nonlinear behaviour are considered necessary for fully characterizing vehicle transient response. Linear characteristic values and functions are determined with tests in the frequency domain and nonlinear characteristic values and functions with tests in the time domain. In the case of vehide combinations, it is pnrnanly the response of the first vehicle unit that is evaluated
Important characteristics in the time domain are
— time lags between steering-wheel angle, lateral acceleration and yaw velocity.
— response times of lateral acceleration and yaw velocity (see 9.2,1),
- lateral acceleration ga (lateral acceleration divided by steering-wheel angle).
— yaw velocity gain (yaw velocity divided by steering-wheel angle), and
— overshoot values (see 92.3).
Important characteristics in the frequency domain are the transfer functions of
— lateral acceleration related to steering-wheel angle, and
- yaw velocity related to steenrig-wtleel angle.
expressed as gain and phase runctions between Input and output variables.
There are several test methods for obtaining these characteristics in the time and frequency ooma’ris, foaows, the applicability of which depends in part on the size of the test track available.
IMPORTANT — The method of data analysis in the frequency domain is based on the assumption that the vehicle has a Imear response. Over the whole range of lateral acceleration this is unlikely to be the case, Ihe standard method of dealing with audi a situation being to restrict the range of the input so that linear behaviour can be assumed and, if necessary, to pedomi more than one test at different ranges of inputs which together, cover the total range of interest
The objective of these tests is to determine the transient response of a vehicle. Characteristic values and functions of both linear and nonlinear behaviour are considered necessary for fully characterizing vehicle transient response. Linear characteristic values and functions are determined with tests in the frequency domain and nonlinear characteristic values and functions with tests in the time domain. In the case of vehide combinations, it is pnrnanly the response of the first vehicle unit that is evaluated
Important characteristics in the time domain are
— time lags between steering-wheel angle, lateral acceleration and yaw velocity.
— response times of lateral acceleration and yaw velocity (see 9.2,1),
- lateral acceleration ga (lateral acceleration divided by steering-wheel angle).
— yaw velocity gain (yaw velocity divided by steering-wheel angle), and
— overshoot values (see 92.3).
Important characteristics in the frequency domain are the transfer functions of
— lateral acceleration related to steering-wheel angle, and
- yaw velocity related to steenrig-wtleel angle.
expressed as gain and phase runctions between Input and output variables.
There are several test methods for obtaining these characteristics in the time and frequency ooma’ris, foaows, the applicability of which depends in part on the size of the test track available.
