Abstract:Hardpoints determine the position and orientation of the mirrors relative to their mirror cells,and it is key elements of the active optics system and plays a significant role in improving the imaging quality and safety performance of the telescopes.The principles and structures of various kinds of hardpoints are comprehensively summarized,and hardpoint location techniques are introduced in E-ELT,VLT,VISTA and LSST,and they represent a variety of hardpoint location.Finally,the development tendency of the hardpoint location is summarized,and the key structures and technologies of hardpoint location are discussed in detail.Comparing with other types of hardpoint locations,hardpoint location with a hexapod configuration has a wide application prospect.At the same time,a series of solutions to improve the positioning accuracy,axial stiffness and safe reliability are given.