Dynamics Simulation Of The Electric Solar Wind Sail Deployment Process

Deep-space exploration has gradually become one of the hot research directions of experts and scholars in the aerospace field with the continuous development of aerospace technology and industry.Electric Solar Wind Sail as a new type of thruster which is a kind of thruster with infinite specific impulse has attracted the interest of many scholars.In recent years,there have been endless researches on the dynamics and control of electric sails,attitude control,and trajectory optimization.However,there are relatively little researches on E-sail deployment.This dissertation will take electric sails as the research object,and study the modeling and simulation of its deployment process.The main work content includes the following aspects:Firstly,a variable-length cable-beam element model based on the reference node coordinate method is proposed.The geometric configuration of the element is described based on the position of the cable-beam element node and the node slope in the reference coordinate system.the dynamic equation of the element is derived based on the D’Alembert principle since the variable-length element does not conform to the law of conservation of mass.This type of element is suitable for modeling flexible cable-beam multi-body systems with large deformation,large displacement,and large rotation since no small deformation assumption is made for the cable-beam element.This dissertation verifies the reliability of the unit through some examples.Secondly,a spin-stable control scheme is designed for the deployment process of the electric sail.The cable end tension of the metal wire has a greater influence on its stability in the deployment process of the electric sail.,The electric sail is easy to lose stability when the metal wire is in a slack state.Therefore,The optional deployment control plan of the electric sail is designed based on the principle that the metal wire is in a taut state at any time.This control scheme is based on the PID control algorithm based on Kalman filter,takes the tension of the electric sail wire as the feedback signal,and uses the release speed of the electric sail wire and the remote jet device as the output,so as to achieve the purpose of maintaining the stability of the system.Finally,dynamic simulation of its deployment process is performed based on the aforementioned electric sail deployment control scheme.The multi-body system dynamics model of the electric sail is established through the variable length cable-beam element model based on the reference node coordinate formulation introduced above.Combining the designed electric sail unfolding process control scheme to simulate the electric sail deployment process.According to the simulation results,the dynamic characteristics of the electric sail deployment process based on this control scheme are analyzed,thereby the reliability of the design scheme is verified.