Research On Dynamics And Control Of Spinning Tethered Spacecraft System For Artificial Gravity Technology

Long-term weightlessness flight can bring huge influence to astronauts' physiology and psychology.The fundamental way to solve this problem is to create artificial gravity during space flight.In this paper,the tethered spinning spacecraft system is studied,which can create artificial gravity field by using centrifugal force.First of all,the spinning tethered system in which the system spins in the orbital plane is simplified as the dumbbell model while ignoring the flexibility and mass of the tether.Dynamical model and formula of artificial gravity are established based on Newtonian dynamics.Numerical simulation shows that the artificial gravity changes periodically around the value of gravity on earth and the its frequency is outside of the human's sensitive band.On this basis,the arbitrary spinning tethered system on any orbit and with any angle between the spinning plane and orbital plane is also analyzed.In this dissertation,the release of tether are studied in different conditions.Here the dynamical model of the deployment of two-dimensional spinning tethered system is established by using Lagrange analytical mechanics.According to different conditions of release,possible rules are proposed to release the tether and numerical simulation shows that the rules are feasible.Then by applying the method of nonlinear programming,the releasing time is set as optimization index in the situation that only the releasing device can provide tension control.Then the optimal releasing law is attained which is proved feasible by numerical simulation.Besides,several controls are applied in the releasing process of the tether in other situations in which thrusters can be used.Finally spinning tethered system in different situations is simulated and demonstrated using MATLAB/ STK..