卫星机动过程成像的姿态规划与控制研究

Attitude Planning and Control Research of Imaging in Satellite Maneuver Process

对有星载相机的卫星机动过程成像的姿态规划与控制进行了研究。为避免目标姿态的任意性产生的控制转序问题,用四元数描述偏流角跟踪控制。从用户角度出发,提出了两种适于机动过程成像的姿态规划模式:一是指定星体相对轨道系摆扫角速度,通过设定摆扫方向与卫星飞行方向成任意角度,可实现任意方向摆扫成像,另一是指定成像点经纬度条带,可实现海岸线等地面目标成像。在摆扫规划姿态的基础上,将绕相机光轴转过经迭代计算的偏流角作为最终的姿态控制基准,给出了高动态姿态机动控制算法。引入陀螺角速度信息以提高滚动姿态机动过程中的动态特性;将星体当前姿态与目标姿态偏差四元数作为姿态控制基准以实现任意姿态最短路径机动;以飞轮作为姿态控制执行机构,设计PD控制律,在机动过程中对内干扰力矩进行前馈控制。仿真结果验证了所提算法的有效性和工程可操作性,可用于对地成像小卫星机动过程成像的姿态规划与控制。

The attitude planning and control for imaging during the satellite's maneuvering with the spaceborne camera were studied in this paper.To avoid the rotating order caused by the arbitrariness of the target's attitude,the quaternion was used for describing the tracking control of the drift angle.From the user's requirement,two attitude models for imaging during the maneuvering of the satellite were put forward.One was to settle the whiskbroom angle rate of the satellite body relative to the orbit coordinate system,which could realize the any direction whiskbroom imaging by setting any angle between the whiskbroom direction and the flight direction of satellite.The other was to designate the latitude and longitude strip map of imaging point,which could realize the coastline imaging.On the basis of the whiskbroom attitude planning,the drift angle obtained by iterative computation rotating optical axis of camera was served as the base of final attitude control.The high dynamic attitude maneuver control algorithm was presented.The gyro information was introduced to improve the dynamic feature during the maneuvering of rolling attitude.The bias quaternion between the presented attitude of the satellite and target attitude was used as the base of the attitude control to realize the shortest maneuvering route with any attitude.The wheel was used as the actuator of the attitude control and PD control law was designed to implement the feedforward control of inner disturbance moment during the maneuvering.The simulation results verified the effectiveness and high precision of the algorithm proposed,which could be applied in attitude planning and control of imaging in attitude maneuver process for micro satellite.