Attitude motion planning for a spin stabilised disk sail

While solar sails are capable of providing continuous low thrust propulsion the size and flexibility of the sail structure poses difficulties to their attitude control. Rapid slewing of the sail can cause excitation of structural modes, resulting in flexing and oscillation of the sail film and a subsequent loss of performance and decrease in controllability. Disk shaped solar sails are particularly flexible as they have no supporting structure and so these spacecraft must be spun around their major axis to stiffen the sail membrane via the centrifugal force. In addition to stiffening the structure this spin stabilisation also provides gyroscopic stiffness to disturbances, aiding the spacecraft in maintaining its desired attitude. A method is applied which generates smooth reference motions between arbitrary orientations for a spin-stabilised disk sail. The method minimises the sum square of the body rates of the spacecraft, therefore ensuring that the generated attitude slews are slow and smooth, while the spin stabilisation provides gyroscopic stiffness to disturbances. An application of Pontryagin’s maximum principle yields an optimal Hamiltonian which is completely solvable in closed form. The resulting analytical expressions are a function of several free parameters enabling parametric optimisation to be used to provide reference motions which match prescribed boundary conditions on the initial and final configurations. The generated reference motions are utilised in the repointing of a 70m radius spin-stabilised disk solar sail in a heliocentric orbit, with the aim of assessing the feasibility of the motion planning method in terms of the control torques required to track the motions.

[1]  R. Beard,et al.  Successive Galerkin approximation of nonlinear optimal attitude , 1999, Proceedings of the 1999 American Control Conference (Cat. No. 99CH36251).

[2]  B. Wie,et al.  Time-optimal three-axis reorientation of a rigid spacecraft , 1993 .

[3]  P. Tsiotras.  Stabilization and optimality results for the attitude control problem , 1996 .

[4]  Colin R. McInnes,et al.  Technology requirements of exploration beyond Neptune by solar sail propulsion , 2010 .

[5]  Osamu Mori,et al.  On-orbit verification of fuel-free attitude control system for spinning solar sail utilizing solar radiation pressure , 2011 .

[6]  Colin R. McInnes,et al.  GeoSail: an elegant solar sail demonstration mission , 2007 .

[7]  Marcel J. Sidi,et al.  Spacecraft Dynamics and Control: A Practical Engineering Approach , 1997 .

[8]  Hans Seywald,et al.  Minimum fuel spacecraft reorientation , 1994 .

[9]  David Murphy,et al.  Solar-Sail Attitude Control Design for a Flight Validation Mission , 2007 .

[10]  Thimo Oehlschlägel,et al.  High performance two degrees of freedom attitude control for solar sails , 2011 .

[11]  Nadjim Horri,et al.  Optimal geometric motion planning for a spin-stabilized spacecraft , 2012, Syst. Control. Lett..

[12]  Timothy W. McLain,et al.  Successive Galerkin Approximation of a Nonlinear Optimal Attitude Control , 1999 .

[13]  V. Jurdjevic.  Geometric control theory , 1996 .

[14]  Rajesh Rajamani,et al.  Vehicle dynamics and control , 2005 .

[15]  David L. Elliott,et al.  Geometric control theory , 2000, IEEE Trans. Autom. Control..

[16]  Stephan Theil,et al.  PERFORMANCE ANALYSIS OF AN ATTITUDE CONTROL SYSTEM FOR SOLAR SAILS USING SLIDING MASSES , 2011 .

[17]  Bong Wie,et al.  Space Vehicle Dynamics and Control , 1998 .

[18]  John E. Prussing,et al.  Solar Sailing: Technology, Dynamics, and Mission Applications , 2000 .

[19]  R. C. Thompson,et al.  Survey of time-optimal attitude maneuvers , 1994 .

[20]  C Circi,et al.  Solar sail attitude control through in-plane moving masses , 2008 .

[21]  M Polites,et al.  Solar sail attitude control using small reaction wheels and magnetic torquers , 2008 .

[22]  Colin R. McInnes,et al.  Solar Polar Orbiter: A Solar Sail Technology Reference Study , 2006 .

[23]  Bong Wie,et al.  Solar Sail Attitude Control and Dynamics, Part 1 , 2004 .

[24]  Willem H. Steyn,et al.  Cubesat solar sail 3-axis stabilization using panel translation and magnetic torquing , 2011 .

[25]  D. D. Mueller,et al.  Fundamentals of Astrodynamics , 1971 .