A high-performance vibration isolation platform （VIP） has been developed for a cluster of control moment gyroscopes （CMGs）. CMGs have long been used for satellite attitude control. In this paper, the influence of ...A high-performance vibration isolation platform （VIP） has been developed for a cluster of control moment gyroscopes （CMGs）. CMGs have long been used for satellite attitude control. In this paper, the influence of flexible solar arrays on a passive multi-strut VIP of CMGs for a satellite is analyzed. The reasonable parameters design of flexi- ble solar arrays is discussed. Firstly, the dynamic model of the integrated satellite with flexible solar arrays, the VIP and CMGs is conducted by Newton-Euler method. Then based on reasonable assumptions, the transmissibility matrix of the VIP is derived. Secondly, the influences of the flexible solar arrays on both the performance of the VIP and the stability of closed-loop control systems are analyzed in detail. The parameter design limitation of these solar arrays is discussed. At last, by selecting reasonable parameters for both the VIP and flexible solar arrays, the attitude stabilization performance with vibration isolation system is predicted via simulation.展开更多
In this paper, an attitude maneuver control problem is investigated for a rigid spacecraft using an array of two variable speed control moment gyroscopes （VSCMGs） with gimbal axes skewed to each other. A mathematica...In this paper, an attitude maneuver control problem is investigated for a rigid spacecraft using an array of two variable speed control moment gyroscopes （VSCMGs） with gimbal axes skewed to each other. A mathematical model is constructed by taking the spacecraft and the gyroscopes together as an integrated system, with the coupling interaction between them considered. To overcome the singular issues of the VSCMGs due to the conventional torque-based method, the first-order derivative of gimbal rates and the second-order derivative of the rotor spinning velocity, instead of the gyroscope torques, are taken as input variables. Moreover, taking external disturbances into account, a feedback control law is designed for the system based on a method of nonlinear model predictive control （NMPC）. The attitude maneuver can be realized fast and smoothly by using the proposed controller in this paper.展开更多
Attitude control system is one of the most important subsystems in a spacecraft.As a key actuator,the control moment gyroscope(CMG)mainly determines the performance of attitude control system.Whereas,the control accur...Attitude control system is one of the most important subsystems in a spacecraft.As a key actuator,the control moment gyroscope(CMG)mainly determines the performance of attitude control system.Whereas,the control accuracy and output torque smoothness of the CMG depends more on its gimbal servo system.Considering the constraints of size,mass and power consumption for a small satellite,here,a mini-CMG is designed,in which the gimbal servo system is driven by an ultrasonic motor.The good performances of the CMG are obtained by both the ultrasonic motor and the rotary inductosyn.The direct drive of gimbal improves its dynamic performance,with the output bandwidth above 20 Hz.The angular and speed closed-loop control obtains the 0.02°/s gimbal rate,and the output torque resolution better than 2×10^(-3) N·m.The ultrasonic motor provides 1.0N·m self-lock torque during power-off,with 12arc-second position accuracy.展开更多
控制力矩陀螺(control moment gyroscope, CMG)是飞行器在轨姿态控制的重要执行机构之一,通过内部高速旋转的飞轮储存角动量,利用伺服机构驱动框架旋转输出力矩。安装隔振器可有效减少由高速旋转飞轮产生的不平衡力对飞行器上高精度载...控制力矩陀螺(control moment gyroscope, CMG)是飞行器在轨姿态控制的重要执行机构之一,通过内部高速旋转的飞轮储存角动量,利用伺服机构驱动框架旋转输出力矩。安装隔振器可有效减少由高速旋转飞轮产生的不平衡力对飞行器上高精度载荷的影响。建立伺服机构三环控制模型和一个单自由度隔振器模型,揭示了隔振器引起伺服系统速度环耦合失稳的现象。通过分析隔振器频率、阻尼比、惯量等关键设计参数对速度环稳定性的影响,对隔振器进行详细设计,试验结果全流程验证了考虑伺服机构控制稳定性的CMG隔振器设计流程和隔振效果,为同类型产品设计提供了工程经验。展开更多
提出了一种基于磁力发生器的控制力矩陀螺(Control Moment Gyroscope,CMG)动载荷主动补偿方法来改善轴系工况。首先介绍磁力发生器的结构与工作原理,给出磁力发生器的设计参数;然后对CMG系统进行动力学建模;接下来通过等效磁路法与有限...提出了一种基于磁力发生器的控制力矩陀螺(Control Moment Gyroscope,CMG)动载荷主动补偿方法来改善轴系工况。首先介绍磁力发生器的结构与工作原理,给出磁力发生器的设计参数;然后对CMG系统进行动力学建模;接下来通过等效磁路法与有限元法对装置的输出特性进行计算,通过实验测试磁力发生器的静态和动态输出特性,与计算结果进行对比,并对模型参数进行拟合;最后通过仿真研究磁力发生器的动载荷主动补偿效果。展开更多
Spacecraft require a large-angle manoeuvre when performing agile manoeuvring tasks, therefore a control moment gyroscope(CMG) is employed to provide a strong moment.However, the control of the CMG system easily falls ...Spacecraft require a large-angle manoeuvre when performing agile manoeuvring tasks, therefore a control moment gyroscope(CMG) is employed to provide a strong moment.However, the control of the CMG system easily falls into singularity, which renders the actuator unable to output the required moment. To solve the singularity problem of CMGs, the control law design of a CMG system based on a cooperative game is proposed. First, the cooperative game model is constructed according to the quadratic programming problem, and the cooperative strategy is constructed. When the strategy falls into singularity, the weighting coefficient is introduced to carry out the strategy game to achieve the optimal strategy. In theory, it is proven that the cooperative game manipulation law of the CMG system converges, the sum of the CMG frame angular velocities is minimized, the energy consumption is small, and there is no output torque error. Then, the CMG group system is simulated.When the CMG system is near the singular point, it can quickly escape the singularity. When the CMG system falls into the singularity, it can also escape the singularity. Considering the optimization of angular momentum and energy consumption, the feasibility of the CMG system steering law based on a cooperative game is proven.展开更多
为提高敏捷挠性航天器在轨连续机动的快速性和高稳定性,应用变速控制力矩陀螺(variable speed control moment gyroscopes,VSCMGs)作为姿态控制执行机构,提出了一种将观测器与自适应控制结合的姿态控制律与VSCMGs复合操纵律。考虑到机...为提高敏捷挠性航天器在轨连续机动的快速性和高稳定性,应用变速控制力矩陀螺(variable speed control moment gyroscopes,VSCMGs)作为姿态控制执行机构,提出了一种将观测器与自适应控制结合的姿态控制律与VSCMGs复合操纵律。考虑到机动过程中挠性模态及精确惯量不可知,采用模态观测器和转动惯量估计器对不可测的状态或参数进行辨识,辨识结果用于精确估计前馈补偿力矩,利用Lyapunov分析方法证明了闭环控制系统的稳定性。鉴于VSCMGs实际使用的力矩分配能力、避奇异能力、轮速平衡能力与末态框架角定位能力,分别设计了加权伪逆操纵律与3种对应的零运动。基于雅可比矩阵条件数提出了末态框架角的优选方法,给出了VSCMGs零运动在机动过程不同阶段的部署方案。结果表明:通过连续姿态机动数值仿真验证了所提算法的有效性;VSCMGs在连续机动过程中平滑切换模式,在不同的机动阶段实现了相应功能。模态观测值和惯量估计值在多次机动后收敛至真值附近,经过参数辨识后的控制器使航天器在机动末端更快更稳地达到指向精度要求。展开更多
针对挠性航天器系统中同时存在单框架控制力矩陀螺群(Single gimbaled control moment gyroscopes,SGCMGs)摩擦非线性、电磁干扰力矩、惯量摄动以及外部干扰等问题,提出了一种有限时间自适应鲁棒控制(Finite-time adaptive robust contr...针对挠性航天器系统中同时存在单框架控制力矩陀螺群(Single gimbaled control moment gyroscopes,SGCMGs)摩擦非线性、电磁干扰力矩、惯量摄动以及外部干扰等问题,提出了一种有限时间自适应鲁棒控制(Finite-time adaptive robust control,FTARC)方法.针对系统中存在未知参数的情况,分别设计自适应更新律,使得控制器的设计不依赖参数信息,同时减小外部干扰对系统的不利影响.应用Lyapunov稳定性理论证明了闭环系统姿态角误差和姿态角速度误差可在有限时间内收敛到原点附近的邻域内.仿真结果表明,所提控制律可实现挠性航天器姿态快速机动,并获得甚高指向精度.展开更多
针对双框架控制力矩陀螺(double gimbal control moment gyro,简称DGCMG)内外框架间的耦合力矩和航天器快速机动带来的牵连力矩引起框架角速率波动问题,建立了动基座下DGCMG框架伺服系统的动力学模型,提出了一种基于扩张状态观测器(exte...针对双框架控制力矩陀螺(double gimbal control moment gyro,简称DGCMG)内外框架间的耦合力矩和航天器快速机动带来的牵连力矩引起框架角速率波动问题,建立了动基座下DGCMG框架伺服系统的动力学模型,提出了一种基于扩张状态观测器(extended state observer,简称ESO)的扰动力矩估计方法。对耦合力矩、牵连力矩等扰动力矩进行估计并采用力矩前馈的方式进行补偿,从而抑制扰动力矩对框架伺服系统控制精度的影响。仿真及实验结果表明,该控制方法能有效抑制由于扰动力矩引起的框架速率波动,提高了框架的速率输出精度。展开更多
文摘A high-performance vibration isolation platform （VIP） has been developed for a cluster of control moment gyroscopes （CMGs）. CMGs have long been used for satellite attitude control. In this paper, the influence of flexible solar arrays on a passive multi-strut VIP of CMGs for a satellite is analyzed. The reasonable parameters design of flexi- ble solar arrays is discussed. Firstly, the dynamic model of the integrated satellite with flexible solar arrays, the VIP and CMGs is conducted by Newton-Euler method. Then based on reasonable assumptions, the transmissibility matrix of the VIP is derived. Secondly, the influences of the flexible solar arrays on both the performance of the VIP and the stability of closed-loop control systems are analyzed in detail. The parameter design limitation of these solar arrays is discussed. At last, by selecting reasonable parameters for both the VIP and flexible solar arrays, the attitude stabilization performance with vibration isolation system is predicted via simulation.
基金supported by the National Natural Science Foundation of China(Nos.11372130,11290153,and 11290154)
文摘In this paper, an attitude maneuver control problem is investigated for a rigid spacecraft using an array of two variable speed control moment gyroscopes （VSCMGs） with gimbal axes skewed to each other. A mathematical model is constructed by taking the spacecraft and the gyroscopes together as an integrated system, with the coupling interaction between them considered. To overcome the singular issues of the VSCMGs due to the conventional torque-based method, the first-order derivative of gimbal rates and the second-order derivative of the rotor spinning velocity, instead of the gyroscope torques, are taken as input variables. Moreover, taking external disturbances into account, a feedback control law is designed for the system based on a method of nonlinear model predictive control （NMPC）. The attitude maneuver can be realized fast and smoothly by using the proposed controller in this paper.
基金supported by the National Natural Science Foundation of China(No.51575260)the Fundamental Research Funds for the Central Universities(No.NJ20160001)
文摘Attitude control system is one of the most important subsystems in a spacecraft.As a key actuator,the control moment gyroscope(CMG)mainly determines the performance of attitude control system.Whereas,the control accuracy and output torque smoothness of the CMG depends more on its gimbal servo system.Considering the constraints of size,mass and power consumption for a small satellite,here,a mini-CMG is designed,in which the gimbal servo system is driven by an ultrasonic motor.The good performances of the CMG are obtained by both the ultrasonic motor and the rotary inductosyn.The direct drive of gimbal improves its dynamic performance,with the output bandwidth above 20 Hz.The angular and speed closed-loop control obtains the 0.02°/s gimbal rate,and the output torque resolution better than 2×10^(-3) N·m.The ultrasonic motor provides 1.0N·m self-lock torque during power-off,with 12arc-second position accuracy.
文摘控制力矩陀螺(control moment gyroscope, CMG)是飞行器在轨姿态控制的重要执行机构之一,通过内部高速旋转的飞轮储存角动量,利用伺服机构驱动框架旋转输出力矩。安装隔振器可有效减少由高速旋转飞轮产生的不平衡力对飞行器上高精度载荷的影响。建立伺服机构三环控制模型和一个单自由度隔振器模型,揭示了隔振器引起伺服系统速度环耦合失稳的现象。通过分析隔振器频率、阻尼比、惯量等关键设计参数对速度环稳定性的影响,对隔振器进行详细设计,试验结果全流程验证了考虑伺服机构控制稳定性的CMG隔振器设计流程和隔振效果,为同类型产品设计提供了工程经验。
文摘提出了一种基于磁力发生器的控制力矩陀螺(Control Moment Gyroscope,CMG)动载荷主动补偿方法来改善轴系工况。首先介绍磁力发生器的结构与工作原理,给出磁力发生器的设计参数;然后对CMG系统进行动力学建模;接下来通过等效磁路法与有限元法对装置的输出特性进行计算,通过实验测试磁力发生器的静态和动态输出特性,与计算结果进行对比,并对模型参数进行拟合;最后通过仿真研究磁力发生器的动载荷主动补偿效果。
基金supported by the National Natural Science Foundation of China (61973153)。
文摘Spacecraft require a large-angle manoeuvre when performing agile manoeuvring tasks, therefore a control moment gyroscope(CMG) is employed to provide a strong moment.However, the control of the CMG system easily falls into singularity, which renders the actuator unable to output the required moment. To solve the singularity problem of CMGs, the control law design of a CMG system based on a cooperative game is proposed. First, the cooperative game model is constructed according to the quadratic programming problem, and the cooperative strategy is constructed. When the strategy falls into singularity, the weighting coefficient is introduced to carry out the strategy game to achieve the optimal strategy. In theory, it is proven that the cooperative game manipulation law of the CMG system converges, the sum of the CMG frame angular velocities is minimized, the energy consumption is small, and there is no output torque error. Then, the CMG group system is simulated.When the CMG system is near the singular point, it can quickly escape the singularity. When the CMG system falls into the singularity, it can also escape the singularity. Considering the optimization of angular momentum and energy consumption, the feasibility of the CMG system steering law based on a cooperative game is proven.
文摘为提高敏捷挠性航天器在轨连续机动的快速性和高稳定性,应用变速控制力矩陀螺(variable speed control moment gyroscopes,VSCMGs)作为姿态控制执行机构,提出了一种将观测器与自适应控制结合的姿态控制律与VSCMGs复合操纵律。考虑到机动过程中挠性模态及精确惯量不可知,采用模态观测器和转动惯量估计器对不可测的状态或参数进行辨识,辨识结果用于精确估计前馈补偿力矩,利用Lyapunov分析方法证明了闭环控制系统的稳定性。鉴于VSCMGs实际使用的力矩分配能力、避奇异能力、轮速平衡能力与末态框架角定位能力,分别设计了加权伪逆操纵律与3种对应的零运动。基于雅可比矩阵条件数提出了末态框架角的优选方法,给出了VSCMGs零运动在机动过程不同阶段的部署方案。结果表明:通过连续姿态机动数值仿真验证了所提算法的有效性;VSCMGs在连续机动过程中平滑切换模式,在不同的机动阶段实现了相应功能。模态观测值和惯量估计值在多次机动后收敛至真值附近,经过参数辨识后的控制器使航天器在机动末端更快更稳地达到指向精度要求。
文摘针对挠性航天器系统中同时存在单框架控制力矩陀螺群(Single gimbaled control moment gyroscopes,SGCMGs)摩擦非线性、电磁干扰力矩、惯量摄动以及外部干扰等问题,提出了一种有限时间自适应鲁棒控制(Finite-time adaptive robust control,FTARC)方法.针对系统中存在未知参数的情况,分别设计自适应更新律,使得控制器的设计不依赖参数信息,同时减小外部干扰对系统的不利影响.应用Lyapunov稳定性理论证明了闭环系统姿态角误差和姿态角速度误差可在有限时间内收敛到原点附近的邻域内.仿真结果表明,所提控制律可实现挠性航天器姿态快速机动,并获得甚高指向精度.
文摘针对双框架控制力矩陀螺(double gimbal control moment gyro,简称DGCMG)内外框架间的耦合力矩和航天器快速机动带来的牵连力矩引起框架角速率波动问题,建立了动基座下DGCMG框架伺服系统的动力学模型,提出了一种基于扩张状态观测器(extended state observer,简称ESO)的扰动力矩估计方法。对耦合力矩、牵连力矩等扰动力矩进行估计并采用力矩前馈的方式进行补偿,从而抑制扰动力矩对框架伺服系统控制精度的影响。仿真及实验结果表明,该控制方法能有效抑制由于扰动力矩引起的框架速率波动,提高了框架的速率输出精度。
