The Research Of Monitoring System Of Drop Test Machine Based On Virtual Instrement

Package dropping testers are necessary test equipments for package drop testing.Anddrop orientation controlling is the core of the automatic control technology of drop testingmachine. At present, most of the machines are adopted the method that the drop range isartificial fixed,and thus has lower credibility.In order to reduce the complex operation andimpact of human error factors, the main study in this thesis is designed a drop test controlsystem based on virtual instrument LabVIEW.The thesis is based on sensor technology, virtual instrument technology,C51SCMdevelopment technology, and using the C language, G language as the programminglanguage and LabVIEW, KeilC51as the software development platform.The design schemeof observation system of packing drop test machine is constructed from a user’sperspective.Specific research results and conclusion as follows:(1) According to the development situation of drop test machine,studing experiences andachievements of previous and combining with virtual instrument technology, the controlsystem scheme of drop test base on LabVIEW is confirmed.(2) Designing and producting the force sensor used for measuring the force of the fallingobjects.(3) the amplifying circuit is composed of AD620and AD711JN, amplifying the millivoltsignal to voltage.(4)The driving schemes of the42HS4808stepping motor of automatic lifting device andstepper motor of horizontal moving are completed.42HS4808stepper motor is driven byL298,and stepper motor is driven by ULN2003. The stepper motor programming is in thelower computer SCM STC89C52and through serial port,upper computer LabVIEW controlstepper motor by control character.(5)The drop platform of drop tester is desiged and producted. Electromagnet ZE32andstepper motor2are installed in the platform.And through power-on and power-off of theelectromagnet,we can control open and close of the platform. Driving the holder moved alongthe guide rail, stepper motor2can trim package. (6) Selection of PCI2003data acquisition card, by CLF calling DLL database comingwith PCI2003card, the drive of acquisition card is done. Through graphical programming inthe LabVIEW platform, the work of data acquisition and analysis is realized.(7)Through debugging and experiment,it proved that magnification times ofamplification circuit is1000times,and through power-on and power-off of the electromagnet,open and close of the platform can be realized,and also the correct control of step motor andcollection and analysis work accurately by LabVIEW can be achieved.Experimental results indicate that package drop tester control system can realize itsmonitoring control function,work in good condition and achieve the desired requirements.