The Design And Research Of Liquid Level Measure Device Based On Linear CCD

The aim of this subject is to design a liquid level measure device used for measuring theliquid level of sulfuric acid accurately inside large lead acid battery in ships. The difficultiesare the strong corrosion of the liquid medium, the demand to achieve a relatively highprecision which is affected directly and complicated by the shaking of ship and the highlyrigorous demands on power dissipation, volume, installation and maintenance.In this thesis, firstly we introduce the background of the subject, the current developmentstatus of liquid level measure system and the objective and significance of our research.Secondly the principle of the device is explicated in detail and the system feasibility analysisexperiment is made to confirm the feasibility of the design scheme. Thirdly the chip model ofeach module of the device is determined for the fundamental implementation. The design ofthe FPGA minimum system and the timing of the system are described in detail whichincludes the regulation of the linear light source, the driving timing of the linear CCD andA/D, data pretreatment, communication between FPGA and DSP, watchdog and displaymodule etc. Finally, after analyzing the results of the calibration the device and the testexperiment, the technical indexes reaches the predefined target.The liquid level measure device is not just limited the operation under the specialsituation, it could also be widely used in other fields because of its advantages such as thecapability of anti-shaking and anti-tilt against the measured liquid, the minimal influence byliquid concentration, simple structure, easy to maintenance, working in a corrosive or evenworse environment, lower cost etc.