Nc Tool In Situ Measurement System Based On Line Structured Light

International Organization for Standardization(ISO)has specified the tool radial wear as tool wear standard in finish machining because tool flank wear often occur in finish machining and the dimensional accuracy of machined part is directly affected by the tool flank wear degree.So it is a great significance if the radial dimension of tool can be obtained at different time.A NC tool in situ measurement system based on Line Structured Light is developed,a camera and two lasers are used to form a two line structured light sensor,and suitable devices such as camera and lasers are choosed.According to the actual measurement environment,radius and rotary axis contraint least square cylinder axis fitting method is proposed,which use points of light stripe on the tool handle as feature points to fitting tool axies,and this method makes the tool axis can be measrued rapidly,and it met the needs of in situ measurement.And the measurement results are corrected on account of the analysis on the impact which is caused by the eccentric clamp.In order to extract the center of the irregular light stripe on the surface of tool,a continuous varied-boundary guassian fitting method is used to extract center of structured light stripe.Grayscale barycenter method is used to extract the center of light stripe roughly,then calculate normal of light stripe by differential mean value theorem,finally,according to the width of the light stripe,use guassian fitting method in the direction of the normal direction of the light stripe to extract the center of light stripe.The tool damage judgment is completed according to the shape of light stripe,and the radial dimension of the tool is obtained by dealing with point cloud data in real time.The NC in situ measurement system is set up,the sensor calibration experiment,scanning accuracy verification experiment and the NC tool in situ measurement experiment are carried up,the experiment result show that the characteristics of the surface of the tool can be obtain by the measurement system in real time.