Research And Design On Signal Collecting And Control System Of Roundness Tester

The roundness tester is a high precision instrument that is wildly used to measure the rotary workpiece in mechanical industry. Having been used for a long time, the performance of these imported roundness testers descends ,and their failure increases ,many ones even can not work properly. Therefore, it is important to transform the traditional roundness testers. The rapid development of computer technology and the born of virtual instrument has brought about a new revolutionary change in the measuring instrument. Under this background, it is not only feasible but also meets the need of science development to do research on reformation of the traditional roundness testers using virtual instrument technology.This research completes the following task in terms of the reformation of the Signal Collecting and control system of the roundness tester.Firstly, on the basis of looking up and deep studies of relative literature data home and abroad ,this paper studies the working principle of the roundness tester , tests its performance and parameters ,analyses the existence problems of the talycenta roundness tester before the reformation and makes feasible reformation scheme.Secondly, this paper gives a way to adopt virtual instrument into the reformation of the roundness tester, chooses the hardware and devises software of VI. In terms of hardware, this paper retains the original mechanical structure of the roundness tester using Siemens S7-200 PLC as the core controller and builds the motor control system and data collection system. In terms of software, this paper suggests that using LabVIEW, which issued widely in CAT field by the American National Instruments Corporation as the software development platform, developing the communications program of LabVIEW and PLC, on the basis of which , building motor control and data collection software platforms of roundness tester. To Make PLC program of LabVIEW and PLC communication, motor control and data collection.Thirdly, this paper analyses the principle of the least squire circle method (LSC), estimates the deviation from the circle centre of the measured workpiece to the round-table, and realize alignment function through aligning motor.Finally, this paper makes actual test and analysis by using of virtual instruments for roundness tester. The experiment proves that this roundness tester meets roundness detection needs, its accuracy can meet the requirement for the use of virtual instruments for roundness. This paper provides a basis for the future theory and practice.