Large spaceborne optical load necessitates an exceptionally serene on-orbit environment to achieve high precision but is subject to micro-vibration and attitude adjustments. At present, the Stewart platform is often adopted and implemented in micro-vibration isolation. However, based on the common model design, the actual decoupling performance of the Stewart platform is still problematic and significantly affects the image quality of the optical load when performing attitude adjustments. Therefore, this work develops a comprehensive parametric model of the Stewart platform to analyze its coupling property. Firstly, a Stewart platform is introduced and its comprehensive dynamic model is established while considering more influential parameters such as the positioning of flexible joints and the detailed equivalent modeling of the legs. Secondly, by comparing the common model and the comprehensive model, the latter significantly reduces errors in the stiffness of the system and modal frequencies. Therefore, relevant parameters are redesigned to meet decoupling requirements and target modal frequency based on the comprehensive model. Using the finite element model and the numerical simulation model of the platform, it is demonstrated that parameters designed based on the comprehensive model effectively decrease the multi-degree-of-freedom coupling degree, and ensure effective micro-vibration control during attitude adjustments.

中文翻译：

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用于大星载光载荷的 Stewart 平台的综合参数模型和去耦设计


较大的星载光学负载需要一个异常宁静的在轨环境才能实现高精度，但会受到微振动和姿态调整的影响。目前，Stewart 平台经常被采用并实现在微隔振方面。然而，基于通用模型设计，Stewart 平台的实际去耦性能仍然存在问题，并且在进行姿态调整时会显著影响光负载的图像质量。因此，这项工作开发了一个 Stewart 平台的综合参数模型来分析其耦合特性。首先，引入 Stewart 平台并建立其综合动力学模型，同时考虑更有影响力的参数，如柔性关节的定位和腿部的详细等效建模;其次，通过比较通用模型和综合模型，后者显著降低了系统刚度和模态频率的误差。因此，基于综合模型重新设计了相关参数，以满足解耦需求和目标模态频率。利用有限元模型和平台的数值仿真模型，证明了基于综合模型设计的参数有效降低了多自由度耦合度，保证了姿态调整过程中有效的微振动控制。