Design And Research On Electronic Control Unit Of FPEG

Free-Piston Engine Generator(FPEG)is a new power equipment with many advantages,including simple structure,low friction,high energy conversion efficiency,high power density and fuel adaptability.The structure of this model is quite special,the right and the left sides of the piston is connected by a steel linear motor core in the middle,and engines on both sides drive the motor core into motion alternately such that the linear motor generate electricity.However,no fixed axial constraint on the movement of the piston results in the difficulty of the piston's stability control,and this problem is now a major limitation to the development of FPEG.In order to provide an appropriate hardware platform for investigating the operating stability of FPEG,this paper carried out the design and development of the Electronic Control Unit(ECU)of the existing prototype,designed the overall architecture of the ECU,completed the design and manufacture of hardware,compiled the control software for lower machine,implemented the serial communication between PC and PLC machine.Details of the research design and achievements are as follows:1)Analyzed the overall control requirements of FPEG,refined and produced each independent module,determined the scheme and selected key components for each module.Firstly,a basic architecture was determined with a STM32F407 adopted as the core of the control unit and an EP4CE6E22C8 N adopted as the core of the redundant computing.Then,with considerations of FPEG's operating characteristics as well as thoroughly analysis and comparison,various sensors and actuators were selected including a SR27 A magnescale.Finally,chose C language as the main programming language for MCU and G language as the main programming language for PC.2)Completed the hardware design for FPEG's first generation of the ECU free piston generator engine electronic control unit based on the design idea that the core plate and the bottom plate were in separation.The processor's unit circuit,data acquisition circuit,actuator drive circuit,communication circuit and connector circuit are designed respectively.Completed the development of the circuit successively,including schematic drawing,PCB board layout wiring,components selecting and overall ECU producing.3)Based on the embedded hierarchical idea,designed and developed the internal drive layer,basic layer and application layer of ECU.Adopted STM32 CubeMX as an auxiliary programming tool for the drive layer,which was quite advanced in the field of embedded software development and helped complete the programming of all peripheral underlying drivers and chip initialization efficiently.In MDK-ARM,wrote important functions of the basic layer and implemented a simple control strategy of the application layer.4)Developed the serial communication part of PC program,and realized the serial communication between PC and ECU.