Development Of Cylinder Pressure On-line Measurement System Based On FPGA For Marine Engine

Cylinder pressure indicator diagram is one of the important performance parameters of an engine.All the cylinder pressures of the engine can be measured synchronously and analyzed,and the arameters can be extracted by the cylinder pressure on-line measuring system.The working condition of the engine are identified by contrasting the all cylinder pressure indicators and the characteristic parameters extracted.Therefore,it is significant engineering application to develop the cylinder pressure on-line measurement system for marine engine.High-precision cylinder pressure sensor is expensive and short server life,which limits the engineering application of the the cylinder pressure online measurement system.Nowadays,the most of the cylinder pressure for the engine are measured one by one.Due to the cylinder pressure sensor for monitoring is launched,which has the longer service life and the lower price,it is possible to measure the all cylinder pressures of the engine synchronously by using the cylinder pressure on-line measurement system.The cylinder pressure on-line measurement system for the marine engine is developed based on FPGA in the thesis.The hardware circuits are designed and the measurement software are developed.The functions and the precision of the marine engine cylinder online pressure measurement system are verified by the experiment.The main contents and conclusions are shown below:1.In order to meet the requirement of the measurement environment of the cylinder pressure on-line measurement system,the main function module's chip selection and the circuits are designed on the Cadence hardware design platform.The cylinder pressure acquisition,DDR3 memory,Ethernet communication and a serial port turn USB communication are included in design.The functions of the data acquisition,the storage,the data sending and the series-parallel conversion are implemented in the hardware system designed,which has the good stability and the high reliability.2.The control logics of A/D data acquisition,the data processing,storage,the Ethernet sending module and the serial port turn USB communication module are developed.The multi-channel data synchronous acquisition and the series-parallel conversion under synchronous clock and DDR3 data storage and Ethernet data sending are achieved,which meet the requirement of the design.3.The marine engine cylinder pressure online is validated on the simulation experiment platform,its functions and precisions of the measurement system are verified by analysing.