Key Technical Research On The Stewart Platform For Precision Tracking Systems

In recent years,precision tracking technology for carrier platforms such as spacecraft has become a key technology point in future optical applications.The current beam accurate pointing tracking is usually achieved by servo turntable,although it has high precision and large range of motion,but its weight volume is larger,not only increases the carrying cost and reduces the stability of the mechanism,in addition to the series structure is also easy to cause cumulative motion error.Stewart platform was proposed by Stewart in the 1970 s,with high precision,stable structure,compact size and other advantages,in motion simulation,vibration isolation,medical and other applications.Since the 1990 s,it has been applied to the support adjustment platform of space precision optical equipment,but its research application as a tracking platform in optical system is not mature,and there are many difficulties to be overcome,so it is of great practical significance and practical value to carry out the research of precision tracking technology based on Stewart platform.In summary,this paper has carried out a specific study on the key technologies in the structure of The stewart platform for precision tracking system:1.Based on the needs of the tracking system,a Newart platform configuration design and parameter optimization method for the tracking system is proposed,and the design principle prototype is experimented to verify the feasibility of the configuration design method.This method is simple and fast,and improves the design efficiency of Stewart platform configuration.2.As the core component of Stewart platform,the actuator directly affects the motion performance of the platform,and in this paper,a piezoding stepping actuator is designed,and the key components of the actuator are analyzed by finite element simulation,including the stiffness analysis of the drive mechanism and the static analysis of the clamp mechanism,and finally the motion performance of the actuator is tested by building a test system.The action mechanism has the characteristics of high precision,fast response speed,no mechanical clearance,low energy consumption and large movement stroke,which creates the conditions for the large-scale precision tracking of the tracking system.3.Hinge as the connecting part of Stewart platform,is the key part to ensure the accuracy of platform motion,this paper designs a flexible hooke hinge with a large corner,and the flexible hooke hinge is static simulation analysis,modal simulation analysis and shaft drift simulation analysis,and finally the experiment shows that the flexible Hooke hinge around the X-axis and Y-axis rotation travel can reach ±9 degrees.This solves the problem that rigid hinges have gap friction and the current flexible Hooke hinge corner is small,and provides technical support for the high-precision large-scale movement of Stewart platform.