Abstract: Lightweight highrigid structure is the pursued goal of space mechanical structure mechanism. Based on the size and mechanical testing of the rod structure of Typha orientalis Presl, a light weight and high rigid bionic rod structure is proposed for space applications. Specifically, taking the application of the bionic rod in the precision flexible mechanism as the background, the influence of the hinge deformation of the flexible mechanism in the commonly used electromagnetic force balance sensor on the measurement result is analyzed. The relationships between the electromagnetic force at any equilibrium position, the hinge moment and the load force are solved respectively. Taking the straight circle chain as an example, the force measurement error caused by the displacement error is calculated. It is pointed out that when the load action line passes through the midpoint of the links, the mechanism only produces Y direction displacement. The bionic rod structure is used to perform finite element simulation analysis on the precise flexible mechanism with a certain geometric size. The simulation results show that the maximum difference between balance force and loading force is 1.9×10-5N and the error is 0.0038%. And the lightweight high rigid bionic rod structure can be used in precision flexible mechanisms, other large space expandable antenna mechanisms, in space station ultralong operating arms and other related fields.

Key words: typha, bionic rod, flexible hinge, error analysis