Desenvolvimento de um sistema de medição de nível de combustível não invasivo para um protótipo tipo Baja SAE

Abstract

Monitoring some critical variables helps the pilot when making decisions, such as the best time for a fuel stop. Motivated by this situation, this work presents the development stages of a fuel level sensor, aimed at the application in a vehicular prototype of the Baja SAE category. The sensor is proposed for use with the Briggs & Stratton model 799863 fuel tank, given the geometric characteristics of this tank, which impacts the geometry of the transducer. This device is basically composed of three functional blocks. The first one is responsible for identifying the fuel level present in the tank, through the insertion of electrodes in cavities in the lower part of the tank, which act as a capacitor, and the variation of this capacitance changes the output frequency of an oscillator circuit. The second block has a frequency-voltage converter circuit, which allows the interpretation of the level information, through an electrical variable. And, finally, the last block is responsible for conditioning the signal, adjusting the voltage level, to ensure safety and compatibility with the microcontroller that will receive this signal. The proposed solution presented promising results in the simulation and individual testing stages, however in the final application, the result was not as expected, due to repeatability problems in the measured capacitance values.