Patent ID: 9663252
Date: 2017-05-30
CPC Classifications: B64G,F16F

Claim:
1. A method for attitude controlling based on finite time friction estimation for a flexible spacecraft, the control method comprising the following steps: a) introducing spacecraft flywheel friction disturbance into a flexible spacecraft dynamics system, and establishing a flexible spacecraft dynamics system Σ b) converting the flexible spacecraft dynamics system Σ c) constructing a flywheel friction disturbance estimator, the flywheel friction disturbance estimator estimating a value of a flywheel friction moment, wherein the method for constructing the flywheel friction disturbance estimator comprises the following steps: 1) establishing a flywheel dynamics model, the flywheel dynamics model being expressed as: wherein Ω(t) is a rotational speed of a motor in a flywheel, the rotational speed is an angular speed, {dot over (Ω)}(t) is an angular acceleration of the motor in the flywheel, {dot over (M)} 2) constructing the flywheel friction disturbance estimator, the flywheel friction disturbance estimator being expressed as: wherein {circumflex over (Ω)}(t) is an estimated value of the rotational speed Ω(t) of the flywheel, {circumflex over (M)} wherein the parameters k d) constructing a flexible appendage vibration disturbance observer, the flexible appendage vibration disturbance observer estimating a value of flexible appendage vibration disturbance; 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; wherein the compound controller is used to compensate for flywheel friction according to the estimated value of the flywheel friction moment; and the compound controller is used to compensate for the flexible appendage vibration disturbance according to the estimated value of the flexible appendage vibration disturbance to perform spacecraft attitude control.