Online Thickness Monitoring And Controlling System For Continuous Press Machine In Wood-based Panel Production

Mat forming is an important process in the production of wood-based panel(WBP).Controlling the thickness of Mat accurately and effectively plays an very important role in theprocedure to guarantee high qualities of the products. Also, mat thickness is one of the keyindicators to determine the qualities of WBP because mat thickness is highly associated withdensities and qualities of WBP. Mechanical properties such as MOR have tight relationshipwith thickness and densities of WBP. So, in the process of WBP manufacturing, thickness ofmat must be controlled within certain limitation and variance. Inventing a system who cancontrol the mat thickness precisely and effectively is very necessary.Base on the knowing of all the current monitoring system of mat thickness, a researchapplying virtual instrument design method in order to build a mat thickness automaticallymonitoring system has been developed in this paper. Though considering about the requirementof mat thickness controlling, laser sensor and mechanical sensor combined testing system withthe help of LabVIEW developing software was designed in the paper.This thesis discusses the design and implementation of the on-line monitoring systemof wood-based panel thickness. It introduces the structure and the working principle of thesystem, and also explains the development at the virtual instrument and software designing. Inthe end, it also analyses the reasons of the error and provides settle methods, analyses the testdata of the system. Main content as follows:1) In order to achieve the slab thickness of the precision measurement, considering themat thickness measurement requirements, using a laser sensor (IPF PT663023)anddifferential displacement sensors(DC10) combination testing to detect mat thickness.2) To differential displacement sensor measuring axis at the end of the reformation andexpand the measurement area, reduced friction and improve the measuring accuracy.3) Design and realization of the lower computer control system, including the dataacquisition card, linear module, etc and cooperate with each other, realize the systemautomatic operation. LabVIEW virtual instrument based on the development platform, andstudies the graph visualization of on-line monitoring control system.4) The temperature and linear aspects of the compensation have been made in themat thickness monitoring system. The analysis of data shows that this study of mat thicknessmonitoring system can meet the practical requirement of WBP production. The advantages ofthis system are small size, light weight and low cost. The measurement precision is better than the0.05mm. It is very suitable for China's small and medium-sized WBP's company. It hassome of the popularization and application value.Through the study of WBP thickness on-line monitoring technology, lays a foundationfor our country in the WBP machine state monitoring technology in the field of the theory andprovide the corresponding technical experience. It also has created favorable conditions forour country to develop an advanced and complete set of WBP machinery. For a change in thewhole of our country WBP industry backwardness, make our country WBP production linemonitoring level and modernization degree up to international advanced level in the laid afoundation.