Spacecraft Attitude Tracking Control


The attitude control of rigid bodies has important applications ranging from rigid aircraft and spacecraft systems to coordinated robot manipulators. Rigid spacecraft applications in particular (e.g., satellite surveillance and communication) often require highly accurate slewing and pointing maneuvers of large angle amplitudes. These requirements necessitate the use of the nonlinear dynamic spacecraft model for control system synthesis. Further complications arise from uncertain spacecraft mass and inertia properties due to fuel consumption, payload variation, appendage deployment, etc.

The main problem addressed in this research is the quaternion-based, attitude tracking control of rigid spacecraft without angular velocity measurements and in the presence of an unknown inertia matrix. As a stepping-stone, we first design an adaptive, full-state feedback controller that compensates for parametric uncertainty while ensuring asymptotic attitude tracking errors. The adaptive, full-state feedback controller is then redesigned such that the need for angular velocity measurements is eliminated. The proposed adaptive, output feedback controller ensures asymptotic attitude tracking. This work uses a four-parameter representation of the spacecraft attitude that does not exhibit singular orientations as in the case of the previous three-parameter representation-based results. To the best of our knowledge, this represents the first solution to the adaptive, output feedback, attitude tracking control problem for the quaternion representation. Simulation results are included to illustrate the performance of the proposed output feedback control strategy.

For the full conference paper, please visit

B. T. Costic, D. M. Dawson, M. S. de Queiroz, and V. Kapila, "A Quaternion-Based Adaptive Attitude Tracking Controller Without Angular Velocity Measurements," Proc. of the IEEE Conference on Decision and Control, Sydney, Australia, Dec. 2000, pp. 2424-2429.  

Simulation Results

Desired angular position about a) x-axis, b)y-axis, and c) z-axis

Position tracking error

Angular velocity tracking error

Parameter estiamtes

Control Torques

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