Research And Application Of Jet Diffusion Concentration Field Detection System Based On DM6437

In the research of environmental hydraulics,it has been a research hotspot to reveal the flow phenomenon of jet flow and quantitatively measure its concentration field.According to this,this paper presented fast image processing technology into testing jet concentration diffusion area,combined with an experimental platform which took the DM6437 as the core image processing to explore a new kind of laboratory test method of concentration field to observe and analysis jet concentration diffusion in water.The main work is as follows.(1)Experimental facility and detection system for diffusion of concentration field of jet flow were designed.Experimental facility,which mainly contain three parts,facilities for flume device,facilities for jet flow control device and image acquisition and processing system.The flow velocity of water in the flume can be adjusted form storage water tank to flume device.The jet experiment was set to to imitate ambient jet and the flow velocity of Rhodamine B in it can be adjusted by pump and flow control value.The image acquisition device completed the concentration field of jet diffusion image acquisition and digital analog conversion.The image prcessing system included image acquisition and storage,image processing algorithm,image processing display.Image acquisition and storage make the image of jet flow field after digital analog conversion to the buffer.The image prcessing system was responsible for the extraction,processing and algorithm analysis of the characteristic information of the jet concentration field.The paper used Rhodamine B as the tracer to simulate the water pollutant and carry out the calibration experiment to obtain the relation curve between the gray image and the corresponding concentration of Rhodamine B.By using image processing and analysis program we obtain integral information of instantaneous concentration field without any contacting and interference.(2)The hardware design of jet flow concentration field detection system.The hardware system were made up of the SEED_DEC6437 development board as thehardware platform,the DM6437 as the core image processing,PAL standard carema as the image acquisition input terminal,LCD or PC as the image display terminal.TVP5150 decoder chip achieved A/D conversion of the image of jet flow field to BT.656 code stream format of digital parallel signal.Through the analysis of the video transmission and the storage format of the data in the memory,the collection,storage,extraction and transmission of the image information of the jet concentration field can be realized.(3)The software design and development of the jet concentration field detection system.The software system used Matlab and CCS as the main tool.CCS writed the image processing algorithm to deal with the image of the jet flow field through the end of addressing memory area and output real-time jet flow concentration field image via VGA port.After processed by CCS,it would be preserved as the format of.dat while Matlab would draw the concentration contour map of jet flow field.All this done were aiming to obtain integral information of instantaneous concentration field.(4)Study of experiment of concentration field diffusion of jet flow.The paper designed experimental conditions of hydrostatic and hydrodynamic of jet flow field measurement.Through the analysis of the data and the images processing which based on DM6437,verify the feasibility of the the jet concentration field detection system using Rhodamine B as the tracer.Through the analysis of experimental results,the jet concentration field detection system which was designed and developed independently can well describe and analyze the feature of diffusion which provides a new method to study the pollutant concentration field diffusion and its mechanism.