Research And Implementation Of Portable System For Diesel Engine Data Acquisition And Analysis

As an important branch of microcomputer application technology,data acquisition,processing and analysis technology,it is the integration of sensor technology,signal acquisition and conversion technology,and computer technology.It is an important tool and method for obtaining information.In this paper,the advantage and disadvantage of the existing data acquisition equipment used in the experiment of diesel engine are discussed.On this basis,a set of portable system for diesel engine data acquisition and analysis is developed.This system can fulfil the collection,preservation and analysis of diesel engine's temperature,pressure and instantaneous angular speed information.The system includes hardware and software systems.The hardware system is the acquisition terminal used to connect all kinds of sensors.Software system refers to data acquisition and analysis system based on Windows system.The temperature and pressure acquisition part of the acquisition terminal can be applied to all types of temperature and pressure sensors that are frequently used in diesel engine tests.Sensor type parameters can be set directly through software system.In addition,it provides a convenient interface for the connection of different kinds of sensors.The acquisition terminal based on RS-485 bus has the characteristic module extensibility.In practical application,according to the need of testing,the design scheme can be referenced to extend the acquisition module and increase the measurement channel.The instantaneous angular velocity signal acquisition function is based on the principle of A/D conversion.The system has dual channel synchronization data acquisition function.the instantaneous speed signal is acquired by using equidistant black and white paper tape and optical sensors.The data acquisition and analysis software system was developed by Visual Basic,Visual C++,Labview,Matlab and VBA.The system has the function of collecting,saving data,and automatically splitting data files.In the analysis of instantaneous angular speed,the system has the function of merge the teeth together by software processing in order to improve the accuracy of measurement.The torsional vibration angle is analyzed in time domain,and the torsional vibration frequency domain information is obtained by fast Fourier transform.In addition,the effect of teeth merging on identifying the frequency domain information of torsional vibration is discussed,and relevant conclusions are given.The portable system for diesel engine data acquisition and analysis has the characteristics of stable operation,high precision,universal good,module extensibility and so on.This acquisition system is not only suitable for the internal combustion engine condition monitoring and fault diagnosis,but also can provide reference data for further scientific research.It has been widely used in a State Key Laboratory of internal combustion engine.Therefore,it has great practical value.