An Approach for Modeling and Performance Analysis of Three-Leg Landing Gear Mechanisms Based on the Virtual Equivalent Parallel Mechanism

In order to realize the safe taking-off and landing of aircrafts on unstructured terrains, the landing gear on the aircraft is required to have a terrain-adaptive function. As a kind of aircraft onboard equipment, adaptive landing gear puts forward higher requirements for its design. This article proposes a virtual equivalent parallel mechanism (VEPM) modeling and performance analysis approach for the landing gear mechanism with three kinematic branch chains. In this approach, the unstructured terrain data were mapped to a moving platform. The moving platform, virtual restrained chains and the original mechanism of the landing gear mechanism combines the VEPM. In this way, the performance analysis object of the landing gear can be converted from a single kinematic branch to the entire system. The new approach can more effectively evaluate the overall motion performance and stability performance of the landing gear, and can help improve the structural design and control algorithm design of the spacecraft landing gear.