The ground modal test is an important approach to the natural frequency of solar arrays to support the attitude control of spacecraft. However, for the batch production of small satellites, the accuracy and efficiency of traditional ground modal testing methods are limited. This shortcoming restricts the development of satellite constellations. Based on the encapsulation method widely used in the computer field, this paper proposed a natural frequency identification method of deployable solar arrays with multiple plates. This method is of high accuracy and efficiency that meets the demand of attitude control and makes sense to accelerate the batch production of small satellites. First, a suspended modal test system with gravity compensation function is designed. Second, the mathematical model of the test system is established. Abstracting parts of the parameters of the test object into an encapsulated entity, the mathematical model is simplified by equivalent variables. Thus, the direct mapping relationship between the ground test result and the true natural frequency is proposed. Finally, to verify the identification accuracy, finite element analysis (FEA) and the ground modal test of a two-folder solar array simulant are carried out. The results show that the relative error of the first-order natural frequency after correction and the theoretical value is less than 3%. Meanwhile, the identification accuracy of the ground modal test is improved by more than 50%. This method improves the availability of ground test results and reduces the calculation amount, so that it is convenient for engineering applications.

中文翻译：

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基于封装的多板可展开太阳能阵列固有频率识别方法

地面模态试验是太阳能电池板固有频率支持航天器姿态控制的重要手段。然而，对于小卫星的批量生产，传统的地面模态测试方法的准确性和效率是有限的。这一缺点制约了卫星星座的发展。本文基于计算机领域广泛使用的封装方法，提出了一种可展开多板太阳能电池阵的固有频率识别方法。该方法精度高、效率高，满足姿态控制需求，对加速小卫星批量生产具有重要意义。首先，设计了具有重力补偿功能的悬吊模态试验系统。其次，建立了测试系统的数学模型。将测试对象的部分参数抽象为一个封装实体，通过等效变量简化数学模型。因此，提出了地面测试结果与真实固有频率之间的直接映射关系。最后，通过有限元分析（FEA）和两层太阳能电池阵列模拟物的地面模态试验来验证识别精度。结果表明，修正后的一阶固有频率与理论值的相对误差小于3%。同时，地面模态试验识别精度提高50%以上。该方法提高了地面试验结果的可用性，减少了计算量，便于工程应用。