Design And Implementation Of Three-degree-of-freedom Micro Angular Displacement System

In recent decades,more and more scholars from domestic and foreign scientific research institutions and enterprises have begun to pay attention to the research of micro-nano positioning technology.In the micro-nano positioning system,the micro-angular displacement platform is mainly used to generate micro-angular displacement,and has wide applications in remote sensing satellites,precision machining,biomedicine and other fields.With the continuous expansion of the application field of angular displacement platforms and the increasing accuracy requirements,the micro angular displacement platform is developing towards high resolution,large working stroke,three degrees of freedom and compact research.Combined with the existing research designs at home and abroad,it can be found that under the condition that other constraints remain unchanged,the large stroke and high resolution are mutually restricted,and the existing angular displacement platform is difficult to achieve both;for three degrees of freedom The micro-angular displacement platform is usually realized by the sub-platform stacking.The number of sub-platforms increases with the increase of the degree of freedom of the micro-angle displacement platform,which results in the overall structure of the angular displacement platform.Therefore,the structure of the micro-angular displacement platform is complicated.It is also difficult to achieve a balance between degree and multiple degrees of freedom.At the same time,due to the difference in the implementation of the angular displacement of the three degrees of freedom,the angular displacement resolution of each degree is difficult to reach the same magnitude,resulting in a decrease in the overall performance index of the system.The design and implementation of the three-degree-of-freedom micro-angular displacement system for the three-degree-of-freedom micro-angular displacement platform is mutually constrained by the resolution and the working stroke,the overall size and the number of degrees of freedom of motion.The problem is studied.A three-degree-of-freedom micro-angular displacement platform with a three-degree-of-freedom resolution of 0.01??,a working stroke of at least 0-75??,a response frequency of 100 Hz or more,and a volume size of less than 100 mm×100 mm×100 mm is designed.The main research contents of the thesis are as follows:Firstly,the research status of micro-angular displacement platform at home and abroad is analyzed,and the overall structural scheme of micro-angular displacement platform is designed.The current research and analysis of the micro-angular displacement platform design scheme is carried out.It is difficult to simultaneously consider the problems of high resolution and large stroke,and the overall size and degree of freedom of the platform in the existing micro-angular displacement platform.Piezoelectric ceramic drive,a three-degree-of-freedom micro-angular displacement platform with a flexible hinge as the transmission mechanism.The designed micro-angular displacement platform can balance the working stroke and resolution of the output angular displacement under the premise of compact structure.Secondly,the flexible mechanism of the micro-angular displacement platform is rationally designed.A micro-angular displacement platform with a one-dimensional angular displacement sub-platform and a two-dimensional angular displacement sub-platform in series is designed,and a piezoelectric ceramic pre-tightening structure is designed.Based on the characteristics of piezoelectric ceramics and platform design requirements,the flexible joint mechanism in the micro-angular displacement platform was selected and the stiffness analysis was carried out to obtain the relationship between the structural parameters of the flexible hinge and the performance parameters.Thirdly,the theoretical analysis and finite element simulation of the micro angular displacement platform are carried out.The theoretical model of the micro angular displacement platform is obtained by analysis,and the formula of the motion freedom stiffness and the overall natural frequency of the micro angular displacement platform is derived and calculated.And using ANSYS finite element analysis software to verify the correctness of the theoretical calculation results,and finally determine the size parameters of the micro angular displacement platform.Finally,the experimental verification and data analysis of the micro-angular displacement platform were carried out.The micro-angular displacement platform is designed and assembled,the experimental system is built and the angular displacement stroke,angular displacement resolution and dynamic characteristics of the micro-angular displacement platform are tested.The theoretical and simulation results are verified.The experimental results and theories are compared.The difference between the calculation and simulation results is analyzed,and the reason for the deviation of the experimental results is analyzed to ensure that the performance of the micro angular displacement platform meets the designed performance requirements.