基于力状态映射法的航天器非线性铰链参数辨识

Parameter identification of nonlinear joints in spacecraft by force-state mapping

为了解决航天器伸展机构中复杂非线性铰链的建模问题,采用力状态映射法辨识了具有复杂非线性动力学特点的航天器太阳翼根部铰链和板间铰链结构中的多种线性和非线性动力学参数,得到了描述铰链非线性动力学模型的微分方程。为了提供辨识所需的试验数据,根据实际铰链的受力特点,建立了航天器复杂非线性铰链的振动响应试验测试系统,并通过振动试验获得了真实航天器太阳翼根部铰链和板间铰链在不同频率及激振力下的力矩与弯曲角之间的关系。本文的参数辨识结果反映了真实铰链的非线性刚度、摩擦及阻尼特性。利用此辨识参数建立的动力学模型能够描述铰链结构中的多种线性和非线性动力学特点,并可进一步应用于航天器整体系统建模及控制中。

For dynamics modeling of complex nonlinear joints in spacecraft deployable mechanisms, multiple linear and nonlinear dynamic parameters of the joints at the root of solar arrays, and between solar arrays in spacecraft, are identified with the force-state mapping method. Both joint types have complex nonlinear dynamic properties. The differential equations describing the nonlinear dynamic models of such joints are derived. Based on the real force state of joints, a test system is developed to investigate the vibration response of complex nonlinear joints of spacecraft so as to acquire necessary test data. The relationship between moment and bending angle, under various frequencies and excitation forces, is obtained for joints at the root of solar arrays and between solar arrays in real spacecraft. The parameters identified in this paper reflect the nonlinear stiffness, friction and damping characteristics of real joints. The dynamic models established by these parameters can describe multiple linear and nonlinear dynamic properties of joints, and it can be used to entire system modeling and control of spacecraft. The parameters identified in this paper reflect the nonlinear stiffness, friction and damping characteristics of real joints. The dynamic models established by these parameter scan describe multiple linear and nonlinear dynamic properties of joints, and it can be applied to entire system modeling and control of spacecraft.