Study And Implementation Of The Radial Tire Mould Detection System Using Laser

Radial tire mould is used to manufacture all kinds of radial tires, its productquality is very important for radial tire manufacturing. In recent years, the rapiddevelopment of tire industry provides a broad market space for the tire mould industryand makes tire mould industry grow rapidly. The radial tire is a type of tires, whichshares as high as80%of the tire market in recent years. Now the standard of theradial tire mould processing the business propose become more and more high, so theways of processing and detecting are updated and improved.The traditional detection of radial tire mould mainly depends on dialgage, gets themold diameter values by measuring samples artificially. And then by comparing andanalyzing the inner diameter size of sampling points, it forms the product qualityinspection report. The limit of this way is that it takes a lot of manual work, and thesampling is decided by worker completely, precision influence from human factor isvery bigger. The improvement measure method is using the grating scale measure, butit still needs human control readings, and because of the characteristic of the radialtire mould shapes, the measurement accuracy are hard to guarantee. In order toimprove the measurement accuracy and convenience, now more and morephotoelectric technology is introduced to detect the tire moulds, the most significantone is laser sensor.The paper designs a radial tire mould detection system basing on FPGA incombination with grating displacement measurement and laser displacementmeasurement. The detection system not only improves the measurement accuracy andautomation, but also saves measurement cost, which is of great practical value. Thedetection system consists of two major components: mechanical platform subsystem(hereinafter referred to as the mechanical system) and photoelectric detection andcontrol subsystem (hereinafter referred to as the electronic system). The mainly work of the paper is to implement the function of acquiring displacement data andcontrolling stepper motor in electronic system.Electronic system is mainly divided into two parts: the master machine and theslave machine. The slave machine controls the displacement of photoelectricdetection device through the stepper motor, changes the detected points if receivingcommands from the master machine, analyses the data from grating scales then sendsit back to the control procedures of the master machine. At the same time it can alsocontrol the stepper motor movement through the electronic hand wheel, so as toachieve the necessary human intervention in the photoelectric device detectionprocessing. The master machine is an industrial computer where it designs the controlprocedures using VC++software, in which it completes the work of collecting andprocessing the data from laser displacement sensor and slave machine and gets therelative inner diameter size at one point in radial tire mould, then sends controlinstructions to the slave machine. Through measuring multi-point inner diameter ofdifferent patterns of the radial tire mould, it can evaluate its processing quality.In order to improve the measurement flexibility, electronic hand wheel is addedin the photoelectric detection device for manual intervention. In the detecting process,electronic hand wheel and the master machine control the stepper motor movementtogether. The master machine gets the right operation which the stepper motor needsto move basing on the analysis of the data from laser displacement sensor and gratingscale,then gives the correct instructions to FPGA through a serial port. Electronichand wheel fine-tune the stepper motor by judging the current position of thephotoelectric detection device artificially. In order to ensure the safety of the detectionsystem, it designs limit switches at the limit positions of stepper motor travel to limitthe stepper motor movement.This thesis arrangement: the first chapter summarizes the current domestic andforeign tire mould inspection technology situation basically; the second chapterbasically analyses the system principle and key technology, then introduces themechanical part and electrical part and the design tools; the third chapter basically illustrates the hardware of the slave machine including the FPGA control diagram andmodule design, etc.; the fourth chapter is about the control software of the mastermachine which we write using VC++; the fifth chapter is about work summary andprospect forecast.