Optimal Design of High-Precision Focusing Mechanism Based on Flexible Hinge

Abstract

A high-precision focusing mechanism was designed using a flexible hinge to address the demand for precise focusing in space cameras. Firstly, a finite element model of the liner guideway was created using Hertz contact theory, and the accuracy of the model was confirmed using the “flip method”. Subsequently, the flexible hinge was optimized by a mix of topological and integrated optimization. The simulation results demonstrated that the improved flexible hinge successfully eliminates interference between the liner guideway and the screw, minimizes the effects of initial assembly mistakes, and greatly reduces the tilt error of the focusing mechanism. Afterward, the focusing mechanism was subjected to a vibration test, which showed that its first-order fundamental frequency reached 163.28 Hz. This frequency is sufficiently high to minimize the risk of resonance during the launch phase. Ultimately, the tilt error of the focusing mechanism was assessed using both a rigid connector and a flexible hinge. The findings demonstrated that implementing the flexible hinge resulted in a 55.7% decrease in the range of Δθz and a 55.22% reduction in the standard deviation, effectively fulfilling the specified design requirements. This study indicates that the inclusion of a flexible hinge in the focusing mechanism leads to a substantial decrease in tilt error.