Vision system technology determines the placement capability of the surface mount machine and directly affects the placement accuracy and speed of the surface mount machine.
Vision Mounter Working Principle
High-performance surface mount machine commonly use vision centering systems. Vision centering system using digital image processing technology, when the SMT suction nozzle after sucking components, in the process of moving to the patch position, fixed in the patch head or fixed in the body of a position on the camera to obtain the image, and through the image to detect the distribution of the component’s optical density, these optical density in digital form and then through the camera on the camera, many small precision photosensitive components composed of CCD photocoupler array, the output of the 0 ~ 255 Gray-scale value of the level. Gray-scale value is proportional to the optical density, the larger the gray-scale value, the clearer the digitized image. The digital information is stored, coded, amplified, organized and analyzed, and the results are fed back to the control unit, and the results are output to the servo system to adjust the positional deviation of the compensation components to be absorbed, and finally complete the patch operation.
It can visually recognize different components through the visual recognition system, and can mount tiny chip components, fine IC components or shaped components with high speed and high precision.
Based on the vision positioning of the multifunctional mounter important parts, such as mounting spindle, dynamic / static lens, suction nozzle seat, feeder Mark (diameter of 1.00mm holes) mark, machine vision can automatically find out the center of these Mark system coordinates to establish the mounter system coordinate system and PCB, the mounting components coordinate system between the conversion relationship, calculated to the exact coordinates of the three-dimensional movement of the mounter. Coordinates. According to the package type and component number of the imported components, the mounting head grabs the suction nozzle at the corresponding position and sucks up the components. The static lens detects, identifies and centers the suction element according to the vision processing program. After the completion of the alignment of the mounting head will be mounted on the PCB components to a predetermined position. This series of component identification, alignment, detection and mounting actions are industrial control PC according to the corresponding instructions to obtain the relevant data to guide the control system to complete automatically.
Design of Vision Control System
The control system of the multifunctional mounter based on vision positioning mainly accomplishes the functions of X-Y-Z coordinate motion control, image acquisition, automatic in/out and positioning of PCB boards, automatic feeding of feeder, automatic control of vacuum solenoid valve of suction nozzle, etc. The control system of the mounter consists of an industrial PC, which is equipped with an industrial control system and an industrial control system.
The control system of the mounter consists of industrial PC, motion control card, image card, I/O interface board, etc. It realizes the three-coordinate and peripheral I/O interface control, ensures the accuracy and fast response of the motion, and cooperates with the mechanical and visual modules to realize the whole function of the machine. Industrial PC is the core of the whole control system, which realizes the data collection and transmission, analysis and processing of the whole machine, and issues commands to each part to complete the mechanical transmission, image processing and detection functions. The motion control card mainly realizes the acquisition of three-coordinate motion control signals, transmits various processing data, and carries out the instruction function. The image card mainly collects and transmits the data of various mounting components and marking points on the PCB board.
The vision system can exchange information with the database system, control system and system calibration system through the human-machine interface, or exchange information automatically. The vision system can be triggered through the HMI to perform functions such as real-time image acquisition, closing the acquisition, reading in the image, and displaying the image. When the human-machine interface system sends the automatic operation command, the vision system sends the coordinate value to realize accurate placement.
In the vision system of the surface mount machine, two main challenges are solved:
1. The integration of the vision system, which includes LED light source program control, image ingestion, digital transmission, image processing and other technologies.
2. The algorithm, mainly related to component recognition, image processing speed and other issues. The mounter vision system adopts Sony camera and MATROX image processing card to realize the positioning of PCB board, automatic identification, alignment and detection of components, automatic identification of system coordinates, automatic correction of mounting position deviation and other functions, known as the “eyes of the machine”.
Zhejiang NeoDen Technology Co., Ltd. has been manufacturing and exporting various small pick and place machines since 2010. Taking advantage of our own rich experienced R&D, well trained production, NeoDen wins great reputation from the world wide customers.
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Post time: Apr-16-2024