An Investigation of Nonlinear Control of Spacecraft Attitude

• Main Author: Binette, Mark Richard
• Other Authors: Damaren, Christopher John
• Language: en_ca
• Published: 2013
• Subjects: H-infinity control theory; modified Rodrigues parameters; spacecraft attitude control; control theory; 0538
• Online Access: http://hdl.handle.net/1807/42688

The design of controllers subject to the nonlinear H-infinity criterion is explored. The plants to be controlled are the attitude motion of spacecraft, subject to some disturbance torque. Two cases are considered: the regulation about an inertially-fixed direction, and an Earth-pointing spacecraft in a circular orbit, subject to the gravity-gradient torque. The spacecraft attitude is described using the modified Rodrigues parameters. A series of controllers are designed using the nonlinear H-infinity control criterion, and are subsequently generated using a Taylor series expansion to approximate solutions of the relevant Hamilton-Jacobi equations. The controllers are compared, using both input-output and initial condition simulations. A proof is used to demonstrate that the linearized controller solves the H-infinity control problem for the inertial pointing problem when describing the plant using the modified Rodrigues parameters.