Development of a Piston Fuel Flow Meter Based on a Microcontroller and Its Use for Vehicle Diagnostics

During operation, it is advisable to periodically monitor the actual fuel consumption of the vehicle. Fuel consumption can be used to assess the driving conditions and technical condition of the vehicle, which affects the intensity of environmental pollution. The engine control system calculates fuel delivery based on driving conditions and vehicle load based on information from sensors. When diagnosing on fuel economy, it is convenient to directly measure the consumption in the fuel line of the delivery system. The advantages and disadvantages of the main types of different flow sensors were analyzed. It is proposed to measure the amount of fuel per unit of time with a piston volumetric flow meter. The design of a software and hardware system for measuring fuel consumption has been developed, which consists of control systems for the actuators of the flow meter and a system for recording and processing information in a microcontroller. Organized data transfer from the flow meter to an external diagnostic module via the CAN-bus. A protocol was developed for transmitting diagnostic information to a computer and an interface for interacting with the user. The possibility of using a flow meter for measuring differential flow connected in forward and reverse directions is considered. An algorithm has been developed for a program that is embedded in a microprocessor. A procedure was developed for calibrating the flow meter, which allowed an estimate of the total uncertainty. The values of the absolute and relative errors were obtained over the entire range of the measured indicator. The coefficients of linear correction of the working volume of the fuel flow meter are obtained, which are used in the control program for the flow meter. Computer software has been developed that can receive data from the flow meter via USB, displays general information on fuel consumption on the computer screen in graphic and text form. Experimental studies have been carried out to determine the fuel consumption of a passenger car on the road using this flow meter. The use of a fuel flow meter allows you to control the efficiency of fuel supply, timely detect hidden vehicle malfunctions, and assess the quality of operating conditions. Conclusions and recommendations are developed, the main ways of further research are indicated.