The invention provides a stability control method for unfolding of a three-dimensional
space tether system operating in a low earth elliptical
orbit in an initial stage. A tether is released to a desired length and the swing of the tether is restrained only by adjusting the limited tether tension without relying on other thrusters. The method comprises the following steps that S1, a two-body spacetether
system dynamic model considering tether
mass is established; S2, under the conditions such as disturbance, uncertainty,
underactuation, restricted tether swing angle and tether tension, basedon a
nonlinear model predictive control (NMPC)
algorithm, a pseudo-spectral
algorithm is used for discretizing an original
nonlinear model, and an open loop optimal problem in predictive control is transformed into a nonlinear
programming problem for solving; and S3, according to the solution of the nonlinear
programming problem, the control quantity of the next
control period is determined to form the closed-
loop control. Finally, the three-dimensional
space tether system operating in the low earth elliptical
orbit is stably released and unfolded in the initial stage.