Development Of Assembly Equipment For Inertial Components Of Miniature Wire Suspended Pendulum Accelerometer

The miniature wire suspended pendulum accelerometer,which has the characteristics of high accuracy,large range and high shock resistant,is widely used in the inertial navigation of aeronautics and astronautics.The inertial component is the core component of the accelerometer.Its manufacturing and assembly precision will affect the measurement accuracy of the accelerometer.For a long time,the assembly of this type of accelerometer is mainly completed manually by skilled workers with the help of special jig.Its assembly process is not only tedious,time-consuming,low-level automatic.Its mass production is also difficult.In the view of above problems,the assembly requirements of the inertial component of the accelerometer are analyzed.The automatic precision assembly equipment of inertial components was developed to meet the requirements of assembly efficiency and precision.The specific work of this paper includes:According to the assembly requirements of inertial parts,the assembly process flow based on equipment was formulated,and the overall scheme design of automatic assembly equipment was completed.According to the shape and characteristics of the parts to be assembled,The dismountable jig which combined universal jig with special jig was designed to realize the reliable clamping and operation of each part.The Fixture can meet the assembly requirements but not cause parts damage.At the same time,dismountable fixtures were designed to implement subsequent glue drying processes.According to the precision requirement of inertial parts assembly,the hardware was analyzed and selected.The electric power supply control circuit was designed and the construction of inertial assembly equipment was completed.The assembly control strategy is designed according to the subdivided assembly function and the selected hardware.For the non-destructive assembly requirements of suspension wire,The closed loop control of tension force is realized by the combination of wire threading clamp and micro force sensor with high sensitivity in the wire threading mechanism.According to the requirement of parts pose adjustment in assembly process,the pose adjustment strategy based on visual guidance is adopted.The stereo vision measurement module based on monocular camera and reflection prism is constructed to achieve the acquisition of spatial pose image information of each part.Then the relative position and size information between the parts to be assembled are obtained through image processing.And then the pose information obtained by processing is replaced by the adjustment pulse amount of the precision displacement slide of the assembly operation module to complete the displacement adjustment and assembly of the parts.At the same time,the assembly process is visualized.According to the time-step assembly process of inertial components,the assembly of parts can be realized successively.The assembly equipment is equipped with multiple sets of assembly fixtures to ensure the consistency of the work of the assembly.The function and reliability of assembly equipment are verified by debugging and assembly experiments.The error model is established to analyze the factors affecting the assembly accuracy of parts in the equipment and the method to compensate the assembly error is proposed.After the calibration and adjustment of the assembly equipment,the assembly experiment was completed in the ultra-clean laboratory environment.The final results obtained by analyzing the experimental data show that: The assembly equipment of the inertial component of the micro suspended wire pendulum accelerometer can complete the assembly of parts according to the assembly requirements and the assembly precision meets the requirements.