Research And Application Of High Reliability Visual Localization Algorithm For Mounting Machine

In recent years,the rapid development of integrated circuit technology leads to the miniaturization,low power consumption and intelligent direction of electronic components.For the electronic surface mounting industry,the difficulty of component mounting is becoming increasingly high.As the core equipment of surface mounting technology,the mounting efficiency and precision requirements of the mounting machine are also more stringent.In order to further improve the accuracy and reliability of the visual positioning algorithm of the SMT,this paper analyzes the development of the SMT and the research status of the visual positioning algorithm at home and abroad,and learns that the accuracy and stability of the current algorithm in China are vulnerable to the interference of environmental targets,and the accuracy and reliability are poor.Therefore,this paper focuses on improving the reliability of the positioning algorithm,and requires that the algorithm can still achieve stable and high-precision positioning performance in the case of interference.Specific research contents are as follows:(1)In order to improve the reliability of the positioning algorithm,this paper uses image preprocessing technology to improve and optimize the target image containing noise and uneven illumination.The realization principle and function of image grayscale,image filtering,binarization,morphological transformation and edge detection algorithms are introduced in detail.The appropriate algorithm parameters were selected through picture experiment.At the same time,in view of the disadvantage that the Otsuzu threshold segmentation algorithm is easily disturbed by objects,an improvement is proposed,and the minimum error method is introduced to optimize the algorithm.Experiments show that the segmentation effect of the improved algorithm is better than that of the original algorithm.(2)Research on the positioning algorithm of PCB cross datum point.For cross-shaped reference point target with defect interference,two improved algorithms are proposed in this paper.One is to reduce the calculation time of Radon Angle by using Radon linear transformation according to the cross-shape features,and then to improve the linear positioning accuracy by iterative weighted least square method to eliminate the positioning interference.The other method uses LSD line segment detection to obtain continuous line segments by grouping and screening lines and merging rectangles.The feasibility of the proposed algorithm is proved by the simulation experimental data.(3)In order to improve the reliability of the nozzle positioning algorithm of the SMT,this paper proposes an improvement to the Hough circle transformation.The idea of dimensionality reduction and parameter space decomposition is used to introduce the gradient Hough circle transformation,and then the Tukey weight function is used to iteratively fit the circle to improve the positioning accuracy.At the same time,an improvement is proposed for the absence of edge points in the circular arc detection algorithm of ed Circles.The known radius of the outer circle of the suction nozzle is used to extract the circular arc in equal distance segments,and the Angle constraint is used to filter the circular arc segments to eliminate the interference circular arc segments,so as to improve the accuracy and reliability of the algorithm.Finally,the effectiveness of the proposed algorithm is verified by using the simulated experimental data.(4)The experiment verifies the reliability of the positioning accuracy of the algorithm.In this paper,two experimental modes are used to verify the results: one is to use Open CV visual library to simulate the images of interference targets with defects,and the other is to use the camera to collect images for experiments.Finally,the accuracy and reliability analysis is carried out by combining the two groups of experimental data.The results show that the improved Radon transform and LSD-based positioning algorithm have higher accuracy and anti-jamming ability than the traditional algorithm for the cruciform reference point,and the reliability is higher.Among the positioning algorithms of the nozzles of the SMT,both the improved Hoff circle positioning algorithm and the improved e Circuits positioning algorithm in this paper can achieve highly reliable positioning of the nozzles with defect interference,and meet the production requirements.