研究了采用双框架控制力矩陀螺(Double Gimbaled Control Momentum Gyroscope,DGCMG)的敏捷卫星姿态/角动量联合控制问题,针对DGCMG的饱和奇异问题,提出了基于Lyapunov的姿态/角动量联合控制方法。首先,建立了采用两个平行构型DGCMG的...研究了采用双框架控制力矩陀螺(Double Gimbaled Control Momentum Gyroscope,DGCMG)的敏捷卫星姿态/角动量联合控制问题,针对DGCMG的饱和奇异问题,提出了基于Lyapunov的姿态/角动量联合控制方法。首先,建立了采用两个平行构型DGCMG的卫星姿态动力学模型,然后根据陀螺的力矩方程,通过可视化分析得出该构型只有内部隐奇异和饱和奇异两类奇异。隐奇异可以通过操纵律进行避免,而饱和奇异只能通过卸载方式来解决。为了避免采用推力器或磁力矩器等卸载方式带来的问题,设计了连续管理角动量的姿态/角动量联合控制器。此外,为了缩短系统的稳定时间,采用Sigmoid函数对控制器的参数选取进行了改进。该控制器完成敏捷卫星快速机动快速稳定任务的同时,还能连续调节角动量,达到姿态控制和角动量管理的折中。数值仿真结果验证了控制器的有效性。展开更多
A pneumatic parallel platform driven by an air cylinder and three circumambient pneumatic muscles was considered. Firstly, a mathematical model of the pneumatic servo system was developed for the MIMO nonlinear model-...A pneumatic parallel platform driven by an air cylinder and three circumambient pneumatic muscles was considered. Firstly, a mathematical model of the pneumatic servo system was developed for the MIMO nonlinear model-based controller designed. The pneumatic muscles were controlled by three proportional position valves, and the air cylinder was controlled by a proportional pressure valve. As the forward kinematics of this structure had no analytical solution, the control strategy should be designed in joint space. A cross-coupling integral adaptive robust controller(CCIARC) which combined cross-coupling control strategy and traditional adaptive robust control(ARC) theory was developed by back-stepping method to accomplish trajectory tracking control of the parallel platform. The cross-coupling part of the controller stabilized the length error in joint space as well as the synchronization error, and the adaptive robust control part attenuated the adverse effects of modelling error and disturbance. The force character of the pneumatic muscles was difficult to model precisely, so the on-line recursive least square estimation(RLSE) method was employed to modify the model compensation. The projector mapping method was used to condition the RLSE algorithm to bound the parameters estimated. An integral feedback part was added to the traditional robust function to reduce the negative influence of the slow time-varying characteristic of pneumatic muscles and enhance the ability of trajectory tracking. The stability of the controller designed was proved through Laypunov's theory. Various contrast controllers were designed to testify the newly designed components of the CCIARC. Extensive experiments were conducted to illustrate the performance of the controller.展开更多
文摘研究了采用双框架控制力矩陀螺(Double Gimbaled Control Momentum Gyroscope,DGCMG)的敏捷卫星姿态/角动量联合控制问题,针对DGCMG的饱和奇异问题,提出了基于Lyapunov的姿态/角动量联合控制方法。首先,建立了采用两个平行构型DGCMG的卫星姿态动力学模型,然后根据陀螺的力矩方程,通过可视化分析得出该构型只有内部隐奇异和饱和奇异两类奇异。隐奇异可以通过操纵律进行避免,而饱和奇异只能通过卸载方式来解决。为了避免采用推力器或磁力矩器等卸载方式带来的问题,设计了连续管理角动量的姿态/角动量联合控制器。此外,为了缩短系统的稳定时间,采用Sigmoid函数对控制器的参数选取进行了改进。该控制器完成敏捷卫星快速机动快速稳定任务的同时,还能连续调节角动量,达到姿态控制和角动量管理的折中。数值仿真结果验证了控制器的有效性。
基金Project(51375430)supported by the National Natural Science Foundation of China
文摘A pneumatic parallel platform driven by an air cylinder and three circumambient pneumatic muscles was considered. Firstly, a mathematical model of the pneumatic servo system was developed for the MIMO nonlinear model-based controller designed. The pneumatic muscles were controlled by three proportional position valves, and the air cylinder was controlled by a proportional pressure valve. As the forward kinematics of this structure had no analytical solution, the control strategy should be designed in joint space. A cross-coupling integral adaptive robust controller(CCIARC) which combined cross-coupling control strategy and traditional adaptive robust control(ARC) theory was developed by back-stepping method to accomplish trajectory tracking control of the parallel platform. The cross-coupling part of the controller stabilized the length error in joint space as well as the synchronization error, and the adaptive robust control part attenuated the adverse effects of modelling error and disturbance. The force character of the pneumatic muscles was difficult to model precisely, so the on-line recursive least square estimation(RLSE) method was employed to modify the model compensation. The projector mapping method was used to condition the RLSE algorithm to bound the parameters estimated. An integral feedback part was added to the traditional robust function to reduce the negative influence of the slow time-varying characteristic of pneumatic muscles and enhance the ability of trajectory tracking. The stability of the controller designed was proved through Laypunov's theory. Various contrast controllers were designed to testify the newly designed components of the CCIARC. Extensive experiments were conducted to illustrate the performance of the controller.
