Analysis of jitter influence in fast frequency measurements

This paper presents a theoretical analysis of possible jitter impact in application of numeric criterion for fastmeasurement of frequency by coincidence principle. The primary goal is the generation of a signal containing a known amount of each jitter components. This signal was used for testing signals with regular pulse trains. Initially, jitter components are analyzed and modeled individually. Next, sequences for combining different kinds of jitter are modeled, simulated and evaluated. Jitter model simulation in Matlab is utilized to show the independence of frequencymeasurement results on the total jitter present in the reference and desired pulse trains independently. A good agreement between previously introduced theory of fastmeasurement of frequency and simulation in jitter presence is verified; these results allows to engineers use the numeric criterion for fastmeasurement of frequency in spite to interactions among jitter components in various applications for frequency domain sensors

Розробка методу оцінки керованості автомобіля за коефіціентом динамічності

The study has explored one of the most important performance properties of the vehicle, which determines road traffic safety, – control in a steady mode. A method has been suggested for evaluating the stability of a vehicle against yaw with regard to the dynamic factor. We have found a dependence of the dynamic factor on the design and operational parameters of the vehicle. The dynamic factor can be reduced through achieving a neutral steering of the vehicle by controlling the ratio of the total lateral rigidity of the tires of the front and rear wheels. It has been determined that a change in the tire air pressure, measured by the developed algorithm, improves vehicle stability against yawing and thus contributes to traffic safety. In the example of the truck Ural-4320, the suggested method was used to determine the total lateral stiffness of the wheels under the condition of ensuring the vehicle’s neutral steering. The study has revealed that in the case of an equipped vehicle it is necessary to reduce the tire pressure in the wheels on the equalizer trolley in correlation to the air pressure in the tires of the front wheels. The research results can be used both in operating the existing vehicles and for designing new ones.Предложен метод оценки управляемости автомобиля в установившемся режиме движения с помощью коэффициента динамичности. Определено, что изменение давления воздуха в шинах, с использованием разработанного алгоритма, позволяет повысить устойчивость автомобиля против рыскания и, соответственно, безопасность дорожного движения. Полученные результаты могут быть использованы как в процессе эксплуатации, так и при проектировании новых конструкций машин.Запропоновано метод оцінки керованості автомобіля у сталому режимі руху за допомогою коефіцієнта динамічності. Визначено, що зміна тиску повітря в шинах, з використанням розробленого алгоритму, дозволяє підвищити стійкість автомобіля проти рискання і, відповідно, безпеку дорожнього руху. Отримані результати можуть бути використані як в процесі експлуатації, так і при проектуванні нових конструкцій машин.

A Method of Evaluating Vehicle Controllability According to the Dynamic Factor

The study has explored one of the most important performance properties of the vehicle, which determines road traffic safety, – control in a steady mode. A method has been suggested for evaluating the stability of a vehicle against yaw with regard to the dynamic factor. We have found a dependence of the dynamic factor on the design and operational parameters of the vehicle. The dynamic factor can be reduced through achieving a neutral steering of the vehicle by controlling the ratio of the total lateral rigidity of the tires of the front and rear wheels. It has been determined that a change in the tire air pressure, measured by the developed algorithm, improves vehicle stability against yawing and thus contributes to traffic safety. In the example of the truck Ural-4320, the suggested method was used to determine the total lateral stiffness of the wheels under the condition of ensuring the vehicle's neutral steering. The study has revealed that in the case of an equipped vehicle it is necessary to reduce the tire pressure in the wheels on the equalizer trolley in correlation to the air pressure in the tires of the front wheels. The research results can be used both in operating the existing vehicles and for designing new ones