用系繩進(jìn)行空間捕捉的最優(yōu)控制研究.pdf

1、南京航空航天大學(xué)碩士學(xué)位論文用系繩進(jìn)行空間捕捉的最優(yōu)控制研究姓名：陳輝申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：一般力學(xué)與力學(xué)基礎(chǔ)指導(dǎo)教師：胡海巖20080601用系繩進(jìn)行空間捕捉的最優(yōu)控制研究 IIAbstract This study is made to utilize a tether technology for the rendezvous and capture of payloads. A set of non-linear differ

2、ential equations of tethered system with elastic tether is formulated based on Lagrange’s equation. The correct positions at specified time are derived for an optimal rendezvous. A guidance scheme based on the direct Gau

3、ss pseudospectral method that can achieve rendezvous with a payload using a longitudinally flexible tether is demonstrated. Three case studies are considered in which the payload is inclined relative to the tether syste

4、m by 0.5, 1.0 and 1.5 deg. The most rendezvous positions are distributed at the juncture of two orbits. As the inclination of the orbit increases, opportunities for rendezvous become rarer. This is a result of the constr

5、aint on maximum allowable tether length, which limits the excursion of the tether in the out-of-plane direction as the inclination increase. The optimal guidance law is determined by using the direct Gauss pseudospectral

6、 method, and the validity of solution is well demonstrated through case studies. It is shown that the rendezvous maneuver can be achieved by using only tension control and the out-of-plane thrust force. When the initial

7、conditions of deployment are given, the trajectories of the capture seem like an “8”. The trajectories become more complicated when the initial conditions are also taken as parameters for optimization. The results of num

8、erical integration match the direct solutions obtained by using the method of nonlinear programming when the feedback terms of tether length and length rate are included in the tension control law. As indicated in the ca

9、se studies, the proposed scheme not only gives a smooth trajectory of capture mechanism, but also guarantees the high precision for achieving the desired final states of rendezvous. Key Words: tethered satellite; rendezv