Design Of The Detection System Of The Ship's Draft

With the development of marine transport, accuracy of water gauge detection attracts more and more attention. Accurate measurement results can reduce dispute effectively and ensure interests of all sides. Currently man-observed method is mainly used. There is no paper about a whole set of water gauge detection system yet.A complete water gauge detection system based on DSP is introduced in this paper. Hardware design and software design are completed and a method to get the scale value of water gauge is also studied out. The design can be divided into three parts:First:hardware architecture. PAL format video signals gathered by CCD camera are converted to digital signals and then inputted to DM642.JPEG compression is carried out in that DSP chip. The compressed image data is transmitted to PC via Ethernet interface. This system achieves a real-time image data acquisition, compression and transmission. Software design is based on DSP/BIOS RF5 framework. With the use of DDK to drive underlying hardware and NDK is used to achieve network transmission capability. Network transport protocol is TCP protocol with 100Mbps transmission speed.MFC is used to design client interface on PC. Image data reception through Ethernet is completed based on winsock. Image can be real-time displayed on the screen. Appropriate picture is selected to do edge detection algorithm.The distance from the edge to word is obtained by the use of horizontal projection of water gauge. The exact scale value is acquired by that result combined with artificial observation.Experimental results show that the detection system designed can meet real-time image acquisition and transmission requirements, the client can observe clear pictures of water gauge, the accuracy of water gauge detection algorithms is±0.1cm.