Research On The Height Measurement System Of Dispensing Colloid Based On Laser Triangulation

With the rapid development of our country's mobile phone industry and the rapid growth of sales of other electronic products,the traditional occasions that require dispensing are gradually replaced by industrial dispensing robots.At this stage,the visual dispensing robot realizes a series of functions such as guided positioning,dispensing,placement,and quality inspection based on two-dimensional images,but it cannot get height information.In order to enable the visual dispensing robot to obtain the three-dimensional spatial information of the work piece,enhance the detection capability of the dispensing equipment,and improve the automation degree of the visual dispensing robot,with funding from the CC600 project of Changzhou Mingseal Robot Technology Co.,Ltd.,this thesis uses the VS300 C visual dispenser as a platform to design a dispensing colloid height measurement system based on the laser triangulation method.This system mainly includes the laser scanning 3D measurement hardware platform and software platform.The hardware platform collects the contour image of the laser scanned workpiece completes the laser scanning workpiece according to the trigger signal and linear motion,and then transmits the contour image to the PC through the USB3.0 data line,After the software platform algorithm processing on the PC,the real-time 3D reconstruction and display of the workpiece is realized.In addition,the software platform sets camera parameters and acquisition parameters according to operational requirements,to realize online quick calibration,data storage,processing,and glue height detection.The main research content and results of the thesis are as follows:1.According to the requirements of the height detection of the dispensing colloid,the thesis puts forward a platform design scheme of laser scanning 3D measurement system based on laser triangulation.And combined with the glue height detection scene for hardware selection,parameter calculation and wiring debugging,this thesis introduces the principle and key technology in the system realization process in detail.2.This thesis deeply studied the technology of 3D calibration,introduced the realization principle of the traditional perspective projection model calibration method in the Halcon algorithm library,and proposed a direct calibration method based on the scale scaling of the sheet of light model,and carried out the specific realization process and principle of the method elaboration.The performances of the calibrated system were evaluated experimentally by measuring the height of the standard gauge block,including the estimation of the Z-axis range of the system,accuracy analysis,stability analysis,linearity analysis and error analysis.The common problems in the system acquisition process were analyzed and solutions were proposed.3.Designed the software platform of the laser scanning 3D measurement system,and designed the interface of the camera parameters,calibration coefficients,and point cloud reconstruction parameters during the acquisition process according to the requirements of the glue height detection process.Multi-threading technology was used to display the reconstruction process and processing results to ensure real-time and smooth data transmission.Combined with the signal and slot mechanism,the QTree Widget and QStacked Widget are used to perform unified parameter setting management for point cloud processing,analysis,and application functions.Designed the log area to record abnormalities,output results,and prompt information during the operation of the software platform.Combine the functional characteristics of each module and adopt appropriate controls to design the human-computer interaction interface.4.Designed and tested the double-camera module bracket glue height detection function,and the broken glue detection process,algorithm principle and key technology,and conduct experimental evaluation from the detection efficiency and detection performance are introduced in detail.The results showed that the stable acquisition rate of the system can reach 392 fps,and the scanning speed can reach 15mm/s.In the mixed inspection of double-camera modules,the average inspection time for a single piece was 84.5ms,the accuracy rate was 93.4%,the recall rate was 91%,and the detection performances were good,basically met real-time detection requirements.