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

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.