Control And System Calibration Of Precision Assembly Equipment For Micro Inertial Components

Accelerometer is the core sensitive component of inertial navigation and inertial guidance system,which is widely used in aviation,aerospace and other important fields.The inertial component is the core component of the accelerometer,and its assembly accuracy is very important to the performance of the accelerometer.At present,the assembly production of inertial components of pendulum accelerometer mainly depends on manual assembly,but the manual assembly precision is low,the consistency is poor,the scrap rate is high and takes a long time,which can not meet the production demand.In order to solve the above problems and facing the actual production,a precision assembly equipment for inertial components of wire pendulum accelerometer is developed.First of all,according to the assembly task,this paper designs the overall assembly scheme of the inertial assembly equipment of the micro accelerometer,in order to ensure that the assembly accuracy of the inertial components can be strictly maintained in the glue drying process,and to facilitate the subsequent operation of the assembly workers,relevant improvements have been made to the fixture and fixture assembly test.Based on the requirements of hardware design and assembly tasks,the control architecture of inertial assembly system is designed,and the feedback control strategy including mutual adaptation is worked out,and the precision control strategy of fixture guarantee + visual / force feedback adjustment is developed.Among them,in order to improve the accuracy of visual feedback,the method of key edge extraction is studied.The auto-focusing algorithm of eightneighborhood maximum gradient threshold is adopted,combined with the adaptive step-size mountain climbing search algorithm to complete the automatic focus,which solves the problem that the feature of the part is not in the depth of field of the camera during the second image acquisition of "look-move-see-move".In order to realize the data communication and control between industrial control computer and digital camera,precision sliding table,turntable,force sensor and other hardware,the debugging software of inertial assembly system is designed and developed.it provides the data basis of slide position,light intensity and so on for the flow of automatic assembly steps in the later stage.Based on the three-layer software architecture of task layer,strategy layer and behavior layer and the idea of modularization,the automatic assembly control software of inertial components of pendulum accelerometer is developed.The assembly thread is designed to realize the real-time repeatable functions of assembly steps and thread piercing,and a visual video panel and manual control panel are developed to provide a strategic basis for the humancomputer interaction module,thus improving the fault tolerance and stability of the software.Then,based on the pinhole camera model and precision assembly system,the transformation and unification of image coordinate system and imaging plane coordinate system are studied.Due to the high assembly accuracy of inertial components to be assembled,based on the analysis of the factors that affect the assembly accuracy of inertial components,an accurate calibration scheme for key parameters of inertial assembly system is established by using product calibration board and special calibration tools.By using software compensation to modify the key parameters such as pixel size and deflection angle between slides,the assembly system error is reduced and the assembly accuracy and consistency of inertial assembly system are improved.The assembly experiments show that the inertial assembly system and automatic control software of the pendulum accelerometer can meet the assembly accuracy and assembly efficiency requirements of the inertial components,and the consistency of the assembly products is obviously improved.