Deployment And Position Control Of Electrodynamic Tether

In recent years,space debris left in space has become a non-negligible security risk,and a reasonable and feasible method of accelerating debris derailment is imperative.The electrodynamic tether system is a novel and effective method.When the tether moves at high speed in the geomagnetic field,it will induce an potential.At this time,the system can form a closed loop with the charged particles in the space ionosphere.Electric current is generated on the conductive rope and interacts with the geomagnetic field.The resulting Lorentz force decelerates the abandoned spacecraft,which has great application prospects.However,the electric power rope system also faces many difficulties.The control ability of the electric power rope system is very limited,which brings great difficulty to the deployment and position maintenance of the system.In response to the above problems,this paper focuses on the issues of space expansion,position maintenance and off-orbit efficiency analysis of the electric power tether,mainly including the following aspects:First of all,based on the analysis of the structure and principle of the electrodynamic tether system,the two-body orbit dynamic modeling of the electrodynamic tether system including electric potential and other perturbation forces is carried out,especially for the generation of Lorentz force in the electrodynamic tether system.The decisive geomagnetic field and ionosphere were mathematically modeled,and the environmental parameters during the numerical simulation were given.Secondly,for the problem of space deployment of the electrodynamic tether system,the space deployment based on the dumbbell model of the rigid rod hypothesis is studied.By linearizing the nonlinear system at the equilibrium position,the state space of the system is given,and then design the state feedback controller and analyze the stability.Further,an improved space expansion controller design is proposed,constrained by the tension of the electromotive rope.Finally,the effectiveness of the controller is verified by numerical simulation.Then,for the problem of maintaining the spatial position of the electrodynamic tether system,based on analyzing the influence of Lorentz force on the stability of the system,a control strategy for suppressing the rope vibration by controlling the current on and off is proposed;further based on the expansion time The self-synchronizing controller realizesthe periodic control of the in-plane and out-plane angles.Finally,the feasibility of the controller is verified by numerical simulation.Finally,the numerical simulation and efficiency analysis of the derailment process of the electrodynamic tether system carry out.Based on the effect of electrodynamic forces,further considering the impact of other environmental disturbance perturbations during deceleration and derailment,an atmospheric model,earth non-spherical perturbation model,and a three-body perturbation model were established;further,the design included different Various simulation conditions such as track height and different track inclination angles use to derail the efficiency of the electric power rope system through numerical simulation.