In order to design a micro-motion angle displacement mechanism for precision engineering

degree of freedom and constraint pattern of 3HSE and 3HSVR angle displacement mechanisms with three screws are analyzed

it shows that the common angle displacement mechanisms designed via three point supports have the uncertainty of the orientation and motion. On this

an exact constraint angle displacement mechanism with double screws is presented

the mechanism is exactly constrained by six point constraints so that the position and orientation are deterministic at the natural state

and at the input state the number of degree of freedom is equal to the number of the input so that the motion is deterministic. The adjusting orientation principle under different inputs is proofed. Finally

the sensitivity is analyzed via the relationship of kinematic geometry. The result indicates that the sensitivity is superior to 0.83μrad. The angle displacement mechanism only has two inputs. The orientation and motion of the mechanism are deterministic and has good stability. It is suitable for the angle adjustment of instruments and optic elements in precision engineering.