Beihang University

Peixi Zhang

Lei Guo

Jianzhong Qiao

Jianwei Xu

Yukai Zhu

Ran Zhang

Yuhan Xu

Dafa Zhang

The present invention provides a method for refined attitude control based on output feedback for a flexible spacecraft. The control method comprises the following steps of: a) building a flexible spacecraft dynamical system &#x3a3;, converting the flexible spacecraft dynamical system &#x3a3;into a flexible spacecraft dynamical system &#x3a3;, and incorporating spacecraft rigid-flexible coupling dynamic disturbance into the flexible spacecraft dynamical system &#x3a3;; b) constructing an external system &#x3a3;, and describing the rigid-flexible coupling dynamic disturbance through the external system &#x3a3;; c) configuring a disturbance observer for estimating the value of the rigid-flexible coupling dynamic disturbance; d) configuring a dynamic output feedback Hcontroller; e) compounding the disturbance observer in step c) with the dynamic output feedback Hcontroller in step d) to obtain a flexible spacecraft refined attitude control system &#x3a3;; the flexible spacecraft refined attitude control system &#x3a3;compensating for the rigid-flexible coupling dynamic disturbance through the estimated value.

Method for refined attitude control based on output feedback for flexible spacecraft

The present invention provides a method for disturbance compensation based on a sliding mode disturbance observer for a spacecraft with a large flexible appendage, comprising steps of: a) building a spacecraft attitude control system; b) constructing an external system, the external system being incorporated with an uncertain portion of a damping matrix of a flexible appendage of the spacecraft; the external system being incorporated with an uncertain portion of a rigidity matrix of the flexible appendage of the spacecraft and describing a sum of flexible vibration and environmental disturbance; c) configuring a sliding mode disturbance observer for estimating the value of the sum of flexible vibration and environmental disturbance; d) compounding a nominal controller with the sliding mode disturbance observer in step c) to obtain a compound controller; the compound controller compensating for the sum of flexible vibration and environmental disturbance.

Method for disturbance compensation based on sliding mode disturbance observer for spacecraft with large flexible appendage

A method and system for anti-interference compound on-line guidance in the atmosphere-entering stage of a Mars lander is provided in the present invention. The method comprises steps of a) building a dynamics model for the atmosphere-entering phase of a Mars lander to incorporating the disturbance brought by the Mars atmosphere density uncertainty into the dynamics model for the atmosphere-entering stage of the Mars lander; b) constructing a disturbance observer to estimate the disturbance brought by the Mars atmosphere density uncertainty in the dynamics model for the atmosphere-entering phase of the Mars lander; c) building a prediction-correction guidance law, and guiding the heeling angle amplitude of the prediction-correction guidance law by continuously updating undetermined parameters; d) constructing an anti-disturbance composite guidance law to compensate the Mars atmosphere density uncertainty; and e) adjusting the deviation of the landing point of the Mars lander by compensating the Mars atmosphere uncertainty disturbance.

Method and system for anti-disturbance composite on-line guidance for atmosphere-entering phase of a Mars lander

The present invention provides a method for attitude control based on finite time friction estimation for a flexible spacecraft. The control method includes the following steps: a. introducing spacecraft flywheel friction disturbance into a spacecraft dynamics system, and establishing a flexible spacecraft dynamics system with flywheel friction disturbance; b. converting the flexible spacecraft dynamics system with flywheel friction disturbance into a state-space form; c. constructing a flywheel friction disturbance estimator; d. constructing a flexible appendage vibration disturbance observer; and e. combining the flywheel friction disturbance estimator in the step c and the flexible appendage vibration disturbance observer in the step d with a nominal controller to obtain a compound controller; the compound controller compensating for flywheel friction according to an estimated value of a flywheel friction moment; and the compound controller compensating for flexible appendage vibration disturbance according to an estimated value of flexible appendage vibration disturbance.

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Beijing, China

Peixi Zhang