Estimation of the accuracy of measuring vehicle parameters on the stand with running drums

Fuel efficiency is one of the indicators for evaluating the efficiency of rolling stock. The article discusses the main reasons that determine the need to assess the fuel efficiency of road vehicles during their operation. An analysis of recommendations for the accuracy of measuring vehicle parameters in regulatory documents was given. The goal of the work was formulated, which is to develop measures to improve the accuracy of measurements during bench tests of cars. The main features of measuring fuel consumption on a simulation stand with running drums were considered. Formulas for calculating fuel travel on the road and on the stand with running drums were presented. A criterion for the similarity of road and bench tests for the fuel efficiency of a car was determined. The factors that influence the measurement of fuel consumption were considered. The general measuring scheme of the simulation bench was drawn up. The components of the load-speed modes for the stand operation were analyzed. A metrological assessment was made of the equipment used to measure the torque and rotation speed of the drive shaft of the running drums. A diagram of the calibration process of a strain gauge beam was given, which is used to measure the torque on the running drums of the stand and the wheels of a car. An assessment was made of the regularity of the change in the output channel of the measuring signal from the torque. The characteristic of the relative error was obtained for two ranges of load measurements. The influence of the frequency and number of successive measurements on the convergence of the accuracy of determining the fuel consumption, speed and load of the vehicle during bench tests was established. The optimal measurement time was obtained with an acceptable accuracy. The general dependence of the total error in measuring fuel consumption on a stand with running drums was obtained, taking into account the accuracy of measuring, processing and sampling the signal. The influence of the sampling frequency of the analog-to-digital conversion on the measurement accuracy was assessed. Conclusions and recommendations were developed, which indicated the main avenues for further research.