The Architecture Design Of Modular Micro Device Assembly System And Equipment Development

The micro inertial device is the core element of the inertial navigation system,and its performance directly determines the navigation accuracy of the system.As the final link in the manufacture of micro inertial devices,assembly directly affects the performance of the devices.At present,the domestic production of micro inertial devices is mainly assembled by operators manually.Automated assembly technology and equipment have broad application prospects.At the same time,with the ever-changing manufacturing requirements of micro products,modular micro/precision assembly equipment has become a research direction in the field of micro assembly.According to the characteristics and assembly requirements of micro inertial devices,this paper proposes a modular micro device assembly system structure and software architecture.The assembly system includes a precision measurement module based on machine vision,an assembly operation module,and a workbench module.The precision measurement module and assembly operation module are universal and can be designed in series according to assembly needs.The workbench module is designed according to specific assembly tasks.The software architecture is divided into the system control layer,the module strategy layer and the module execution layer,and the function library in the module strategy layer is developed.Aiming at the assembly task of a certain type of micro accelerometer,a micro accelerometer assembly equipment is developed.Based on the structure of the modular micro device assembly system,the equipment is divided into six parts: precision measurement module,assembly operation module,workbench module,operation tool library module,nut assembly module and system control module.The precision measurement module is used for feature detection of parts.The collected images are processed through image filtering,morphological transformation and other image processing technologies,and the linear,circular and rectangular features of the part are recognized by the method of Hough transform and finding contours in connected domain.The assembly work module can exchange work tools,assemble parts and control contact force;workbench module realizes parts clamping,posture adjustment and feeding tasks;work tool library module integrates a variety of adsorption work tools and can realize the exchange of tools in cooperation with the assembly operation module;the nut assembly module can tighten the nut and detect its locking torque in real time;the system control module realizes the control of the assembly process and the human-computer interaction function.The dissertation analyzes the main factors which affect the accuracy of the equipment assembly.Based on the rigid body motion assumption,the error compensation model of the assembly equipment is established using the error matrix method.The dissertation designs a scheme to calibrate unknown parameters in the model and perform experimental verification of the assembly equipment after compensation.Through calibration,the relative movement error of the precision measurement module and the assembly operation module in the core space of the assembly operation is less than 3.5 μm.Finally,the performance test including repetitive positioning accuracy of linear motion platforms,contact force control accuracy and torque control accuracy of the assembly equipment is carried out.Accelerometers are randomly selected for assembly experiment.The experimental results show that the equipment can meet the assembly requirements.