Abstract:

The article presents an integrated engineering education, a successfully implemented stand-alone system for measuring and reporting harmful gases from internal combustion engines, studied by the students in the "Automotive Technology" and "Automotive Electronic Systems" majors at the Faculty of Physics and Technology of Plovdiv University "Paisiy Hilendarski" Bulgaria.

Together with the students, a low-cost prototype of a system for "live" measurement of exhaust gases from car engines was designed and implemented, which allows for every second measurement and monitoring of exhaust gases, as a result of the operation of internal combustion engines - (LPG, Smoke, Alcohol, Propane, Hydrogen, Methane, Carbon Monoxide (CO), NH3, NOx, Benzene, CO2, etc.). The sensors MQ-2, MQ-7, and MQ 135 were used to implement the prototype, which measures the levels of exhaust gases released into the environment by cars.

A dual-core, 32-bit ESP32 microcontroller is used, which processes and displays the measured values from the gas sensors promptly. The system enables the storage of the estimated data, their visualization in real time on an LCD, as well as their serial transmission to a computer.

Students are introduced to the basic concepts and principles of using sensors to monitor the flow of harmful emissions that are emitted during the operation of the car engine.

The goal is to observe the changes in the indicators where new and worn-out automotive sensors – MAS(mass air flow) and lambda sensors, which directly affect the environmental indicators and characteristics of internal combustion engines, are used.

A methodology has been developed for conducting experimental research by the students, who in real-time monitor the consequences arising from the use of old and exploited car sensors (Lamda, MAS) and replacing them with new ones, in which the harmful emissions released from the car are significantly reduced.
In addition, students can perform a both quantitative and qualitative analyses of the amounts of harmful gases in the different modes of operation of gasoline and diesel engines - idling, loaded, and others.

After the conducted experiments, the trained future engineers perform an analysis of the obtained data, thereby acquiring permanent knowledge and skills that favor and help their future improvement in the field of automotive electronic systems affecting the flow of harmful emissions released into the environment from cars.

Keywords:

Live measurements, harmful emissions, sensors, microcontroller.