Development Of Electronic Control System Platform For Two Stroke Air Assisted Injection Engine

Two stroke engines are still the main power devices in the field of low altitude & low speed drone aircraft,unmanned aerial vehicle with light take-off weight and outboard marine because of its advantages in high specific output,low engine mass,simple structure and convenient maintenance.However,facing increasingly serious environmental pollution and energy consumption problem,many countries have already published even more stringent regulation.Therefore,traditional two stoke engine's application range has been limited due to the high HC emission and poor fuel economy caused by the mixture scavenging process.Heavy fuel like diesel and kerosene has higher flash point when compares to petrol.Thus,it is more safety in transportation and storage.But compression ignition mode will make engine work brutally and weaken the original superiority of power/weight ratio.Currently,in order to improve the emission behavior and fuel economy of two stroke engine and achieve the flexibility in fuel choice,in-cylinder direct injection technology has to be applied on two stroke engines.Air assisted injection is the main fuel injection technology to solve above two stroke engine issues owing to the portability of accessory and excellent atomization condition.The project takes two stroke air assisted injection engine electronic control system as research content,aiming to establish the platform for future further research and industrialization.First of all,this paper narrated the development and research status of air assisted injection system,analyzed its basic structure and working principle.After that requirements of high real-time performance,redevelopment and communication for the control system platform were confirmed and general design scheme was proposed.Then,according to needs chip selection was given and circuit design of each functional module was accomplished to establish the hardware basis of platform working.Software design work was accomplished by a method of layering to isolate the underlying program and application software.Complex drive was designed based on general purpose timer array of Infineon 32 bit microcontroller and the special crank signal,real-time operation system which conforms OSEK standard was configured to manage interrupt and task,and based on V-type development process control strategy for platform verification was built by using Simulink.Additionally,calibration platform was developed based on calibration tool INCA of ETAS and CCP.Using external excitation source and related test equipment,integration test was carried out and electronic control platform was preliminarily validated that it could achieve the instantaneity and accuracy both in signal acquisition and output execution.Finally,platform was tested on a Mercury two stroke outboard marine equipped with air assisted injection system in two typical engine working condition: start condition,acceleration and deceleration condition.The results show that the engine can be successfully started,engine speed transit smoothly and engine never stall in acceleration and deceleration process after preliminary calibration.Thus,the electronic control system platform meets the design requirements and can be used in further research.