The Approach Of Real-Time Channel Dredging Measurement System

With the exPending size of boats and shiPs coming in and out of harbours,channel dredging industry is growing rapidly. To guarantee that channels could stillkeep level after being dredged, it is very necessary to adopt real-time channeldredging measuring system which not only shows the flatness of the channel but alsoprevents dredging equipment from being damaged. In answer to this demand, with theaim of facilitating operation, a relatively practical and easily operative real-timechannel dredging measuring system is designed in this paper by making use ofMCS-51 series of monolithic processors as CPU.Measuring mathematical model which fit to the system is set up according to theefficiency of the ship and proper Kalman filter model together with the actualparameter is deduced, eliminating random noise, in addition to that, system functionsand control objects are elaborated and hardware and software function models ofchannel dredging real-time measuring system are divided.Hardware functions are analyzed according to divided hardware function model,proper chips are chosen and characteristics of the chips are explained, besides that,hardware schematic circuit diagram and PCB diagram are designed. Hardwarefunction model has the following three features:1. Two-stage decode technique is adopted making full use of address space.2. Low-noise signal preprocesses circuit is designed in order to improve A/Dconversion accuracy.3. Electronic disk which can keep information at the time of power-fail is designed.System software global structure and system working model are mapped out andassembler language is utilized for designing software programs which control allfunctions, besides that, real-time multitasks supervision is realized with the method ofcombining cycle scanning mechanism and interrupt supervision. Foreground andbackground techniques are adopted to facilitate users and the former is used forinterfacial supervision and the latter for real-time measurement. Control programs ofelectronic disk is designed as well as programs for PC machine to receive and displaydata through the adoption of Visual C++ 6.0.Channel dredging real-time measuring system and concurrent communicationbetween channel dredging real-time measuring system and electronic disk as well asserial communication between electronic disk and PC machine are tested, based onwhich a random signal produced by PC machine and D/A control card which serves asnoise is added to the signals collected by transducer and in this way noise interferencetest is conducted and reliability of channel dredging real-time measuring system isverified.