Structure Design And Related Technology Of Gantry Structure Micro Assembly System

In more and more occasions,with the development of advanced production technology and the needs of practical applications,both the miniaturization of products and the diversification of functions are required.To meet the above requirements,the processing and assembly of micro components must have scientific accuracy requirements.Micro assembly technology is used to make the assembly of micro parts meet the accuracy requirements.At present,the assembly of micro parts has achieved the progress from manual operation to automated operation.Since most of the micro assembly equipment is only designed for the assembly task of only one or several micro parts,there are problems about the equipment such as low equipment utilization.To solve the problems,This paper designs an assembly system.It is equipped with a fixture changing structure which can replace the micro assembly fixture.The assembly system can realize the assembly of parts of different sizes and shapes by changing different clamps.This article analyzes the functional requirements of the assembly system,and divides the system into five modules: the clamp library module,the robot module,the loading and unloading platform module,the assembly platform module,and the vision module.Fixture library module is used to store fixtures and provide changeover stations;Manipulator module is used to realize the operating such as loading and unloading;The loading and unloading platform module provides space for corresponding operations;the assembly platform module is used to achieve assembly tasks;the vision module detects the visual information of the parts and assists in assembly.This paper designs the core structure of the assembly system-the switching structure.The changeover structure can implement functions of the exchange of the mechanical structure,the docking of the gas path,and the transmission of electrical signals.The mechanical structure changeover is realized by power-off protection type magnetic connector and mating ring.The magnetic connector is on the robot module while the ring is on the clamp library module.Each mating ring is connected to a fixture of a micro part to realize the replacement of the fixtures.Airway docking is realized by the cooperation of airway duct and sealing structure.The exchange of electrical signals is realized by using a series of pogo pins and a mating base that is matched with it to contact and compress the pogo pins during the replacement process.In addition,the switching structure is equipped with a force sensor to facilitate the control of the switching force and the assembly force.This paper uses a variable magnification vision system.The paper studies the changes of three important parameters.The focal length extension method is used to calibrate the position and stability of the main point.The change of linear slope is used to calibrate the rotation of the image in the process of variable magnification.The pixel equivalent at each magnification is calibrated using a variable circle array.The appropriate variable magnification motor control scheme and the stability of the pixel equivalent to the height change within the working distance are determined by the array,too.A new calibration board was designed to carry out experiments related to parameter calibration in the process of camera zoom magnification.The results show that it can be applied to industrial production.