Research On Task Execution Module Of The Precise Assembly System For Miniature Inertial Devices

Assembly is one of the most important parts in the manufacturing of miniature inertial devices. At present, this process is mainly accomplished manually with the help of the microscope, in which case the productivity is low and the consistency of the product is poor. Assembly automation is the effective technical means to improve assembly quality of miniature inertial devices and achieve consistency. For the assembly of miniature inertial devices, the automated precision assembly system was developed in this subject. The precision assembly system can be divided into several modules according to the functions, and each functional module was developed based on general requirements to reduce the development cycle of the equipment. Considering the demand of the subject, the task execution module subsystem, which is the core function module of the precision assembly system, was developed in this paper. The functions of the module are mainly to achieve three-dimensional positioning, the pick-up and the assembly of miniature parts.The manipulator integrates precision micro-force sensor, so that the module can detect and control the operational force in real time during the operation of the miniature parts whose fragile structure can be protected at the same time. A clamping device with replaced micro-grippers was designed and the tool library of the assembly operation was developed to achieve the assembly task of multi-parts. The task execution module can assemble multi-parts by changing the micro-gripper.In order to decrease the error introduced by the task execution module during miniature parts’ assembly, the principal influence factors of the task execution module’s accuracy were analyzed and the primary cause of the module’s position error is obtained. Based on the error parameters of the module, the kinematic model of the system with error compensation was established, the calibration program was developed and calibration experiments of the error parameters were finished in this paper.Based on the functional need of the precision assembly system, the architecture of the module driver software was designed and the interface function library of the task execution module was developed applying object-oriented method. And the control software of the module is obtained. When the driver software of the module is integrated in the precision assembly system, as long as the parameter configuration file in the program folder is modified, the module program can automatically read the configuration parameters and achieve the function. This method effectively solves the problem of hardware connection differences between different precision assembly equipment and achieves the portability of the driven software’s model.The task execution module was integrated in two different precision assembly equipment and complete assembly tasks of two different types of miniature inertial devices with other modules, all the reservation functions of the module can be fulfilled successfully.