Dynamic Characteristic Analysis Of Drilling End Actuator And Design Of Presser Foot Unit

With the rapid development of aerospace industry,robotic automatic hole making system gradually replaces manual labor in the field of carbon fiber composite material hole making processing by its high efficiency,and also presents new challenges to the hole making quality.In order to improve the dynamic performance and stiffness of the robot processing system,this paper designs a drilling end-effector and carries out the prediction analysis of the assembly accuracy of the whole actuator;establishes the dynamics model of the whole actuator and analyzes the mechanical characteristics of the actuator;finally proposes a normal vector detection method for the presser foot unit designed in this paper,and builds a presser foot constant force control system.The research mainly includes the following aspects:Firstly,the assembly accuracy of the whole actuator was predicted.Combined with the system composition of the actuator,the tolerances of each part of the actuator were initially defined based on GD&T design principles,and the tolerance analysis model of the actuator was established;after that,the contribution of the tolerances of each part of the actuator was analyzed with the assembly accuracy of the electric spindle as the measurement target,and the tolerance accuracy of different contributions was optimized,so as to predict the assembly accuracy of the whole actuator.Secondly,the mechanical characteristics of the drilling end-effector are investigated.The micro contact deformation of the bonding surface is analyzed,the analytical model of the virtual material of the bonding surface is established,and the property parameter values of the movable bonding surface and the fixed bonding surface virtual material in the actuator are solved;after that,the accuracy of the virtual material model is verified,and the mechanical analysis model of the whole machine is established on this basis,and the force deformation,mode and inherent frequency of the actuator are obtained,which provides a theoretical basis for the subsequent structural optimization of the actuator.The theoretical basis for the subsequent structural optimization of the actuator.Thirdly,the assembly accuracy and mechanical properties of the whole machine are verified and analyzed.During the assembly of actuator parts,the installation accuracy of the guide sub is tested and adjusted to verify the results of the preliminary accuracy prediction;the principle of experimental modal analysis technique is explained,the actuator measurement point layout is established,the actuator whole machine modal experiments are carried out,and the experimental results are analyzed by combining with the finite element method.Finally,the actuator control system is built,and the presser foot pneumatic servo control system is built for the presser foot unit designed in this paper,and the relationship between the air pressure setting value and the pressure detection value is studied;a normal vector detection method adapted to the actuator of this paper is proposed for the limitations of the traditional normal vector detection method,and the detection accuracy and repetitive stability of the method are verified by the prototype.