Research On Control System Of 3D Nondestructive Measurement Device Based On Slice Volume Measurement

In the new 3D nondestructive measurement method based on grid lamellar volume measurement,the measurement data of measured mechanical parts are derived from the lamellar volume division about parts by the measuring device.The precision,control accuracy and stability of the device and its control system will determine whether the final data can effectively complete the 3D reconstruction of the measured mechanical parts in the later stage.Based on the functional requirements of this method,the design of it’s control system is studied.Firstly,based on the new measurement method,this paper summarizes and discusses the development status of 3D nondestructive measurement technology and control system of measuring device at home and abroad.Besides,the key to obtain the measurement data of 3D reconstruction nondestructive measurement of mechanical parts under test is defined according to the measurement principle and current control technology.Therefore,the design of three sub-platforms of the measuring device is introduced.What’s more,the overall design scheme of its control system is determined to achieve high precision,high efficiency and stable lamellar volume measurement functional requirements of the measuring device.Secondly,the design of hardware and software is carried out according to the general scheme.Hardware parts:Determining two Siemens S7-200＿SMART PLC communication as the main control of the device according to comprehensive reliability and accessibility.Then the overflow device and liquid level sensor of the lamellar volume measuring device are designed to improve the measuring accuracy of the overflow liquid.Besides,designing a set of data acquisition and communication control board based on STM32 to realize the acquisition and processing of measurement data and the cooperation of three sub-platforms.As well as,analyzing and adjusting the main parameters of servo system according to the requirement of control precision,and ensuring the precision of repeated positioning error of microstep length within ± 0.005 mm.Software part: the first one,establishing the dual PLC controller in the hardware system.The second one,designing the related control program according to the functional requirements.The last,by developing the upper computer operation software based on LABVIEW,the communication is formed with the lower computer to realize the automatic control,monitoring,data acquisition and analysis processing of the measuring device.Finally,the error of measuring device and control system is analyzed and corrected.Through the comprehensive experiment of measuring four different mechanical parts in different directions,the experimental results show that the allowable error value of measuring grid in each layer is controlled between 5% and7%.The designed control system basically meets the required positioning accuracy and verifies that it has the advantages of stable operation,fast and effective data acquisition,and achieves the overall design required by the subject.