Flight Dynamics and Control Strategy of Electric Solar Wind Sails

Abstract

This paper studies the flight dynamics and control strategy for electric solar wind sails based on the nodal position finite element method, where the coupling effects between tether dynamics and electrical field are considered. A modified throttling control strategy is proposed to control the attitude of electric sails by modulating individual tether voltage synchronously with the spinning motion of the sails. The effects of four critical physical parameters: tether numbers, tether length, sail spin rate, and mass of remote units are investigated. The results show that the effect of the relative velocity of the solar wind has a significant effect on the spin rate of the sail in attitude maneuvering, which in turn affects the attitude dynamics and orbit motion of the sail. Numerical results show that the proposed control strategy work successfully stabilizes the spin rate of sail when the TI type sail is adopted. Nomenclature cd, cmin, cmax = Desired, lower bound and upper bound relative ratio of spin rate.

Stability and control of radial deployment of electric solar wind sail

“…The system parameters of the E-sail in the simulation are given in Table 1 [6,30]. The E-sail is initially…”

“…For example, Fig. 6c The tether experiences a low tension, which suggests a heavy remote unit may be needed to increase the tether's tension resulting from the centrifugal effect for stability if the tether is getting slack [30]. Also, as shown in Fig.…”

“…The definition of the heliocentric-ecliptic inertial frame can be found in our previous works [6,30]. The origin of the body-fixed frame Another is used to apply the thrust conveniently with the origin at the remote unit.…”

A comprehensive review of Electric Solar Wind Sail concept and its applications

“…Recently, Li [89] dealt with the coupling effects between the elastic dynamics of the tethers and the electric field with the aim of investigating the flight dynamics and the control strategy of an E-sail model based on the nodal position finite element method. In particular, Li [89] proposed a modified throttling control strategy to command the E-sail attitude by modulating the tether voltage synchronously with the spinning motion.…”

“…Recently, Li [89] dealt with the coupling effects between the elastic dynamics of the tethers and the electric field with the aim of investigating the flight dynamics and the control strategy of an E-sail model based on the nodal position finite element method. In particular, Li [89] proposed a modified throttling control strategy to command the E-sail attitude by modulating the tether voltage synchronously with the spinning motion. Moreover, the effects of four physical parameters (the number of tethers, the tether length, the sail spin rate, and the mass of remote units) on the orbital and attitude dynamics were investigated, showing that both the maneuverability and the traveled orbital distance increase when the number of main tethers increases, while they decrease when the initial spin rate and the mass of the remote unit increase.…”