基于矢量观测的陀螺故障诊断算法

Gyro Fault Diagnosis Algorithm Based on Vector Observation

卫星在轨运行期间,采用反作用轮进行姿态控制及推力器进行位置保持,星体惯量会发生改变并存在控制力矩.提出了一种基于运动学方程的矢量观测算法应用于陀螺故障诊断,采用广义罗德里格参数描述卫星姿态,避免了四元数存计算过程中出现模值不为一的情况;计算过程中采用四元数进行姿态运动学计算,避免了广义罗格里德参数复杂的积分运算.针对陀螺突变和缓变两种故障,分别在角速度幅值变化很小和幅值缓慢减小两类情况下进行仿真.仿真结果表明,该算法可有效估计星体角速度,在上述两类情况下均能准确地对突变和缓变故障进行诊断,不受星体惯量变化和控制力矩的影响,并且计算量较小,对工程应用具有较好的参考价值.

Using reaction wheels to control the attitude and thrusters for station-keeping,the satellite＇s inertial may be changed.A vector observation algorithm based on kinematics applied to the gyro fault diagnosis is presented in the paper.Using the Generalized Rodrigues Parameters（GRPs） to describe the satellite＇s attitude may avoid that the mode of quaternion is not equal to one.Using quaternion to compute the satellite＇s kinematics can also avoid the GRPs＇ complex integral.Both small change and slow decrease of angular velocity range is simulated when gyro＇s rapid and slow change faults occur.The result shows that the algorithm can estimate body＇s angular velocity effectively and diagnose the gyro fault accurately under the two situations above.The algorithm is not affected by body＇s inertial and control torque with a smaller amount of calculation,and have a potential value to the engineering application.