Li Jinqiang, Li Jie, Qin Li, Liu Wei, Wei Xiaokai, Gao Ning, Liu Yang
National Key Laboratory for Electronic Measurement Technology, North University of China, Taiyuan 030051, China.
Key Laboratory of Instrumentation Science & Dynamic Measurement, North University of China, Taiyuan 030051, China.
Sensors (Basel). 2020 Feb 19;20(4):1131. doi: 10.3390/s20041131.
The isolation rolling platform inside a passive semi-strapdown inertial navigation system can isolate the high-speed rotation of a projectile via bearing to provide a low rotating speed environment for the angular rate sensors inside the platform in order to further improve the accuracy by reducing its measurement range. Aiming at the problem that the internal bearing cannot withstand high overload, an optimal design method for a high overload buffer structure based on point contact spherical cap structure is proposed. Changing the materials of the spherical caps can reduce the deformation of the two spherical caps during impact and reduce the pivoting friction; at the same time, the upper and lower spherical caps are both forced to separate by the spring force after the impact and to eliminate the influence of the pivoting friction torque that is generated by the contact of two spherical caps on the stability of the isolated rolling platform. By virtue of finite element analysis and ground semi-physical simulation experiments, the feasibility of the design is verified. The experiment results show that the design can play an effectively protective role in anti-high overload, and the maximum deformation radius of the optimized point contact spherical cap structure can be reduced by 40.8%; after the upper and lower spherical caps are separated, the isolation rolling platform' capability of anti-high-speed rotation can be improved by 52% under the rotation speed of the main shaft at 10 r/s. In this way, the stability of the platform is improved, thus proving the value of the design method in engineering applications.
被动式半捷联惯性导航系统内部的隔离滚动平台可通过轴承隔离弹丸的高速旋转，为平台内的角速率传感器提供低转速环境，以通过减小其测量范围进一步提高精度。针对内部轴承无法承受高过载的问题，提出了一种基于点接触球冠结构的高过载缓冲结构优化设计方法。改变球冠材料可减少冲击过程中两个球冠的变形，降低枢轴摩擦；同时，上下球冠在冲击后均受弹簧力作用而分离，消除两球冠接触产生的枢轴摩擦扭矩对隔离滚动平台稳定性的影响。借助有限元分析和地面半物理仿真实验，验证了该设计的可行性。实验结果表明，该设计在抗高过载方面能起到有效保护作用，优化后的点接触球冠结构最大变形半径可减小40.8%；上下球冠分离后，在主轴转速为10 r/s时，隔离滚动平台的抗高速旋转能力可提高52%。如此，提高了平台的稳定性，从而证明了该设计方法在工程应用中的价值。
