Development of a methodology for checking the power measurement system on a roller stand of a mobile diagnostic station for cars

Abstract

The development of technical diagnostics of cars should be considered in direct connection with the development of the entire system of their technical operation. Currently, various diagnostic tools have been developed that are used in many industries and transport. Diagnostics of the technical condition of many vehicle units and systems should be considered as a special type of physical modeling, combining physical models with full-scale devices. Diagnostic stands should provide simulation of physical processes occurring in real road conditions. It is important to realistic simulation of the processes of interaction of vehicle elements with diagnostic equipment, taking into account the actually acting forces, which will improve the accuracy of vehicle diagnostics at the stand.

The article discusses the issues of modeling conditions for obtaining diagnostic information about complex objects. As an example, the authors consider checking the traction properties of cars on an inertial roller stand. Such equipment must have a loading device that can ensure the verification of the traction and economic properties of a passenger car. As an alternative to AC and DC electric machines, an axial piston type hydraulic pump motor can be used for the loading device of the roller stand.

For this type of drive, it is necessary to develop a method for determining the power at the wheels of a car. In parallel with typical methods for determining power using balancing devices, it is proposed to measure power for a specific model of the stand by the differential pressure in the hydraulic system.

In addition, the measuring system of the inertial stand must ensure: objectivity of the assessment of the measured parameters; the minimum time required to carry out diagnostic operations; stability of measurements; simplicity and accessibility for service personnel; required measurement accuracy.

For this, methods have been developed for the experimental study of the metrological characteristics (verification) of the power measurement channel and the pressure measurement channel in the stand hydraulic system.

The conclusions substantiated the possibility of using the developed methodology in the design or modernization of inertial roller stands for testing the traction properties of passenger cars.