Research On The Technologies Of Micro-displacement Actuator For Large Aperture Segmented Optical/infrared Telescope

Micro-displacement actuator is the key equipment of the active support system of the telescope,which determines the final imaging quality of the telescope.With the increasing of the telescope aperture,the performance of each part of the telescope needs to be improved,and the current actuator technology has been unable to achieve the expected performance.In order to innovate the structure of the actuator and improve the performance of the actuator,a large stroke flexible actuator based on voice coil motor is designed,and the prototype is manufactured and tested.The design and manufacturing process of the micro-displacement actuator is introduced in detail,and the key technology is analyzed and demonstrated.Firstly,through reading a large number of relevant literature,the development status and shortcomings of the actuator are analyzed,and the research value and significance of the actuator are clarified.According to the structure of actuator,the type of the actuator is classified,the advantages of various types of actuator are analyzed,and the best scheme of actuator is found.In this paper,the elastic disc is combined with linear bearing for the first time,which can reduce the influence of friction,hysteresis and seizure of the actuator on the premise of ensuring the stroke of the actuator.Secondly,the parameters of the actuator are determined,and the structure of the actuator is designed according to the specific design objectives.The stiffness and strength of the key structure and weak parts of the actuator are checked to ensure that the reliability of the actuator meets the requirements.The resolution,error,load capacity,stability and axial stiffness of the actuator are analyzed and calculated to ensure that the function of the actuator meets the requirements.Finally,the actuator is manufactured and the actuator experimental system is built.The positioning accuracy,step load and bandwidth of the actuator are tested,and the experimental results are sorted and analyzed.The actuator designed in this paper has a resolution of 2.5nm and a radial stiffness of 0.52N/um.The load of – 30 N to 143 N can be achieved in the range of ± 10 mm.The load of – 36 N to 260 N can be achieved in the range of ± 5 mm.It can achieve the speed of more than 1.9mm/s.The mechanical deformation error is within 28.5nm.The actuator can achieve 500 nm positioning accuracy.Under the square wave signal of250 nm,the bandwidth of the actuator reaches 20 Hz.Under the displacement signal of2.5um,the response speed of the actuator is less than 70ms.