The Research On Anti-vibration Design For Electronic Balance

An electronic balance is a high-precision mass measuring instrument which is widely used in various fields,such as quality control,chemical,foreign trade,medical,national defense construction and scientific research and so on.Nevertheless,electronic balance has strictly requirement for application environment,and it's easy to be affected by vibration signals.In recent years,with the rapid development of urban rail transportation and construction sites,the demand of electronic balance is increasing.However,the traditional electronic balance is unable to meet the latest measuring requirement.Under the condition of environmental vibration,the problems such as data fluctuation,poor repeatability,low signal-to-noise ratio,low accuracy etc.are likely to occur in practical application.In order to improve the dynamic stability of electronic balance under the premise of ensuring the accuracy of weighing,to study impact of vibration factors on the measurement performance of electronic balance and explore its solution have already been imminent.The main purpose of this thesis is to provide an efficient and reliable method for the treatment of vibration interference,and to improve the measurement performance of the electronic balance,and mainly includes the following content.The first chapter is introduction,which summarizes the origin and research background of the topic,elaborates the research significance for electronic balance anti-vibration technology,introduces the research present situation of electronic balance anti-vibration technology,briefly summarizes the research status of vibration suppression and electronic balance anti-vibration technology based on adaptive filtering.The second chapter analyzes both the source and spectrum influence on measurement performance of the vibration signals,on the basis of in-depth analysis of composition and working principle of different weighing balance sensor,establish of dynamic model of electronic balance weighing system,and deduces the different load cell transfer function.In the third chapter,we briefly analyze the shortcomings of using conventional digital filter to resist vibration filtering,introduce the principle of adaptive filtering algorithm,and analyze the performance of LMS algorithm,and explain the principle of adaptive LMS algorithm to eliminate the interference on electronic balance.In the fourth chapter,aiming at the traditional fixed-step LMS adaptive filter algorithm has self-contradiction among the convergence rate,tracking speed and convergence precision,different improved LMS algorithms are researched,by analyzing the variable step strategy adopted by the classical improved algorithm,and then complete the simulation experiment verification.Finally,the conclusion is drawn that the GVSS-LMS(Gradient Variable Step Size Least Mean Square)algorithm is the best solution for the anti-vibration effect of the strain type electronic balance.In the fifth chapter,considering the accuracy of the electronic analytical balance is higher than that of the strain type electronic balance,and the steady-state error of the GVSS-LMS algorithm is relatively large.The NVSS-LMS(New Variable Step Size Least Mean Square)algorithm is proposed to deal with the anti-vibration filtering for the high precision electronic analytical balance.Firstly,the mechanism of NVSS-LMS algorithm is analyzed in detail,and then the influence of key parameters on the filtering performance is discussed.The adaptive method of key parameters in the algorithm is given.Finally,the simulation experiment is completed.At last,the algorithm discussed above is applied to the different types of electronic balance in the laboratory,and the anti-vibration performance test of the electronic balance is carried out to verify the effectiveness of the algorithm.Simulation and experimental results show that the different types of electronic balance filtered by the corresponding method proposed in this thesis can weigh accurately on ordinary wooden test bench and be free from influence created by impact vibration such as a hammer blowing experiment platform.