Research On The Non-contact Measurement Of Planeness Of Metal Surface For Small Size Radiator

Air cooling is the most common CPU heat dissipation mode at present.In order to ensure the heat radiation performance,the smoothness of the metal surface of the radiator(also called flatness)should meet certain requirements.Now it is widely used in the market of flatness measuring instruments,there are three coordinate measuring instruments and laser flatness measuring instruments.Three coordinate measuring instruments require hand-held measuring heads to be measured on the measuring surface.The accuracy and the efficiency is low.It may take 1~2 minutes to measure a product.The laser measuring instrument is equipped with several laser sensors to measure several points on the detection surface at the same time.Due to the low measuring points,the measurement stability is low,and it is not suitable for measuring surfaces of small size.The advantage of three coordinate measuring instrument is to get more points,relatively small error and good stability.The advantage of laser flatness measuring instrument is that the sensor has high precision.This topic has combined the advantages of three coordinate measuring instrument and laser flatness measuring instrument.The high precision laser sensor is installed on the slide block of two axle slide rail,and the slide rail is controlled by two stepping motors.By using the LabVIEW program and the PLC controller,the position of the sensor can be controlled automatically and accurately,and the data of the laser sensor can be uploaded to the computer.Finally,the flatness error value of the test surface is calculated by the improved minimum inclusion region algorithm.This not only improves measurement accuracy,efficiency and automation,but also measures metal surfaces of relatively small size.The main content of this paper is to design a universal machine.The machine vision is used to measure the surface size of the product before the flatness test,and then the surface size of the arrangement of 16 measurement points,obtained by laser ranging sensor non-contact data indirectly to calculate the flatness of the surface of the radiator and the contact part of the CPU.The test data stored in the database.In order to facilitate data queries,in addition to the main program,a separate program has been written to query all data records within the specified time of the specified product.The development of the equipment has been used,compared with the three coordinate measuring instrument,equipment volume reduced to about half,and the test time is reduced to 1/3 of the original,but also increase the data recording and data query function.Later,through the integration of equipment,it is possible to continue to reduce volume.