| In 2015,the State Council promulgated the implementation of "Made in China 2025" to comprehensively promote the implementation of the strategy of a manufacturing powerhouse."Made in China 2025" takes technology and equipment as the core,upgrades traditional manufacturing,encourages innovation in cutting-edge technologies,and improves the talent training mechanism as its basic tasks.It takes intelligent manufacturing as the main direction and promotes the overall upgrading and reform of the manufacturing industry.The washing machine glass cover is an important part of the washing machine,which affects the sealing and safety of the washing machine.This article takes the detection of the flatness and inner and outer diameter of the glass cover of the washing machine as the research object,and studies the detection theory and software and hardware design parts.According to the actual requirements and the national testing standards,an online testing system for the flatness of the glass cover of a convenient,high-speed and high-precision washing machine has been developed.This thesis first introduces the reasons for glass deformation and the definition of flatness,Utilizes detection algorithms that differ from industry standards,and determines that the overall system plan is to use LVDT displacement sensor as the data acquisition terminal,and transmit the data to the single-chip main control for processing and processing.The data containing the flatness information is sent to the upper computer for processing and display.Secondly,carry out magnetic field analysis and circuit design on the LVDT displacement sensor to understand the internal magnetic field distribution in the static field.In the transient field,the impact on the sensitivity and linearity of the sensor is explored from four aspects: the length of the core,the diameter of the core,the thickness of the shell,and the thickness of the end cover.LVDT circuit design includes excitation drive circuit,input preprocessing circuit,zero voltage compensation circuit,RMS-to-DC detection circuit,filter amplifier circuit,temperature compensation circuit,and finally measured linearity of LVDT displacement sensor to reach 0.59%.Then the system hardware circuit and mechanical test platform are designed.The system hardware main control board uses STM32F103C8T6 as the core,and reads the sensor measurement data through the AD conversion chip.After processing,the data is transmitted to the upper computer through the MAX485 transceiver;the mechanical test platform supports two Kind of test mode.Then write the system software,modify it according to the Modbus Ascii protocol,determine the communication protocol between the lower computer and the upper computer,write the main control function code of the single-chip microcomputer,and write the QT upper computer human-computer interaction interface code.Finally,the system was tested,and the test samples provided by the company were tested one by one on the two mechanical testing platforms.The system testing speed reached 30 per minute,and the accuracy reached 99%.Compared with the current common detection methods,the accuracy rate is increased by 19% and the speed is increased by 50%. |
