红外视轴稳定框架是一个三自由度的框架结构，当框架处于非正交位置时，存在耦合现象，影响系统的稳定精度。本文根据框架的动力学方程进行建模，指出框架间含有复杂的非线性耦合关系，影响视轴稳定的控制系统设计。然后利用非线性解耦控制系统的可解耦性，通过证明得出框架间是可以解耦的。同时，运用微分几何方法实现对框架间的系统解耦。实验结果表明，本文方法可以减少红外视轴稳定框架在处于非正交位置时框架间存在的耦合，进而解决了框架间因耦合产生的对系统图像稳定的影响，提高了系统的稳定性和可靠性。

Infrared sight axis stability framework is a three-degree-of-freedom frame structure. When the frames are in non-orthogonal positions, there will be a coupling phenomenon. This phenomenon will affect the stability accuracy of the system. The system of framework is modeled based on its kinetic equation, and it is pointed out that there is a complex non-linear coupling between the frameworks, and these disadvantages will produce a negative impact on the design of sight axis stabilization control system. Then it is proved that the system can be decoupled by the theorem in non-linear decoupling control system. The differential geometry method is used for decoupling the frameworks system. Experimental results show that this method can reduce the coupling impact between the frameworks when the framework of infrared sight axis stabilization system is in a non-orthogonal position, solve the problem that coupling movement makes the picture unstable, and improve the stability and reliability of system.