Angular velocity stabilization control and attitude stabilization control for an underactuated spacecraft using only two single gimbal control moment gyros （SGCMGs） as actuators is investigated. First of all, the dy...Angular velocity stabilization control and attitude stabilization control for an underactuated spacecraft using only two single gimbal control moment gyros （SGCMGs） as actuators is investigated. First of all, the dynamic model of the underactuated spacecraft is established and the singularity of different configurations with the two SGCMGs is analyzed. Under the assumption that the gimbal axes of the two SGCMGs are installed in any direction, and that the total system angular momentum is not zero, a state feedback control law via Lyapunov method is designed to globally asymptotically stabilize the angular velocity of spacecraft. Under the assumption that the gimbal axes of the two SGCMGs are coaxially installed along anyone of the three principal axes of spacecraft inertia, and that the total system angular momentum is zero, a discontinuous state feedback control law is designed to stabilize three-axis attitude of spacecraft with respect to the inertial frame. Furthermore, the singularity escape of SGCMGs for the above two control problems is also studied. Simulation results demonstrate the validity of the control laws.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
Nonlinear controllability and attitude stabilization are studied for the underactuated nonholonomic dynamics of a rigid spacecraft with one variable-speed control moment gyro （VSCMG）, which supplies only two interna...Nonlinear controllability and attitude stabilization are studied for the underactuated nonholonomic dynamics of a rigid spacecraft with one variable-speed control moment gyro （VSCMG）, which supplies only two internal torques. Nonlinear controllability theory is used to show that the dynamics are locally controllable from the equilibrium point and thus can be asymptotically stabilized to the equilibrium point via time-invariant piecewise continuous feedback laws or time-periodic continuous feedback laws. Specifically, when the total angular momentum of the spacecraft-VSCMG system is zero, any orientation can be a controllable equilib- rium attitude. In this case, the attitude stabilization problem is addressed by designing a kinematic stabilizing law, which is implemented through a nonlinear proportional and deriva- tive controller, using the generalized dynamic inverse （GDI） method. The steady-state instability inherent in the GDI con- troller is elegantly avoided by appropriately choosing control gains. In order to obtain the command gimbal rate and wheel acceleration from control torques, a simple steering logic is constructed to accommodate the requirements of attitude sta- bilization and singularity avoidance of the VSCMG. Illustrative numerical examples verify the efficacy of the proposed control strategy.展开更多
Based on the singular value decomposition theory,this paper analyzed the mechanism of escaping/avoiding singularity using generalized and weighted singularity-robust steering laws for a spacecraft that uses single gim...Based on the singular value decomposition theory,this paper analyzed the mechanism of escaping/avoiding singularity using generalized and weighted singularity-robust steering laws for a spacecraft that uses single gimbal control moment gyros （SGCMGs） as the actuator for the attitude control system.The expression of output-torque error is given at the point of singularity,proving the incompatible relationship between the gimbal rate and the output-torque error.The method of establishing a balance between the gimbal rate and the output-torque error is discussed,and a new steering law is designed.Simulation results show that the proposed steering law can effectively drive SGCMGs to escape away from singularities.展开更多
针对变速控制力矩陀螺(variable speed control moment gyro,VSCMG)作为执行机构应用在敏捷遥感卫星上进行姿态机动时末端模式切换的平稳性和快速性冲突问题,在考虑框架转速误差的基础上,设计姿态误差参数作为切换指标,制定误差参数切...针对变速控制力矩陀螺(variable speed control moment gyro,VSCMG)作为执行机构应用在敏捷遥感卫星上进行姿态机动时末端模式切换的平稳性和快速性冲突问题,在考虑框架转速误差的基础上,设计姿态误差参数作为切换指标,制定误差参数切换区域内的过渡规则,将指令力矩实时分配给控制力矩陀螺(control moment gyro,CMG)和飞轮并分别求解,提出了一种控制力矩陀螺/反作用飞轮工作模式模糊平滑切换操纵律。为了使得姿态机动末端卫星姿态达到姿态稳定度和指向精度要求的时间更短,以该时间为优化指标提出聚类变异改进粒子群算法对该操纵律参数寻优,确定最佳的切换区域和切换参数,并进行了仿真验证。结果表明:改进后粒子群算法在相同的迭代次数中总是表现出比传统粒子群算法更优的适应度,具有更快的收敛速度和更高的收敛精度,参数优化后的模糊平滑切换操纵律相比于现有操纵律能够在较短时间内完成双模式的平滑切换,并在姿态机动末端更迅速地达到姿态稳定度和指向精度要求,提高了遥感卫星敏捷机动与高稳指向的控制性能,有利于高质量完成成像任务。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
文摘Angular velocity stabilization control and attitude stabilization control for an underactuated spacecraft using only two single gimbal control moment gyros （SGCMGs） as actuators is investigated. First of all, the dynamic model of the underactuated spacecraft is established and the singularity of different configurations with the two SGCMGs is analyzed. Under the assumption that the gimbal axes of the two SGCMGs are installed in any direction, and that the total system angular momentum is not zero, a state feedback control law via Lyapunov method is designed to globally asymptotically stabilize the angular velocity of spacecraft. Under the assumption that the gimbal axes of the two SGCMGs are coaxially installed along anyone of the three principal axes of spacecraft inertia, and that the total system angular momentum is zero, a discontinuous state feedback control law is designed to stabilize three-axis attitude of spacecraft with respect to the inertial frame. Furthermore, the singularity escape of SGCMGs for the above two control problems is also studied. Simulation results demonstrate the validity of the control laws.
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。
基金supported by the Innovation Foundation of BUAA for Ph.D Graduatesthe Innovation Foundation of the National Laboratory of Space Intelligent Control
文摘Nonlinear controllability and attitude stabilization are studied for the underactuated nonholonomic dynamics of a rigid spacecraft with one variable-speed control moment gyro （VSCMG）, which supplies only two internal torques. Nonlinear controllability theory is used to show that the dynamics are locally controllable from the equilibrium point and thus can be asymptotically stabilized to the equilibrium point via time-invariant piecewise continuous feedback laws or time-periodic continuous feedback laws. Specifically, when the total angular momentum of the spacecraft-VSCMG system is zero, any orientation can be a controllable equilib- rium attitude. In this case, the attitude stabilization problem is addressed by designing a kinematic stabilizing law, which is implemented through a nonlinear proportional and deriva- tive controller, using the generalized dynamic inverse （GDI） method. The steady-state instability inherent in the GDI con- troller is elegantly avoided by appropriately choosing control gains. In order to obtain the command gimbal rate and wheel acceleration from control torques, a simple steering logic is constructed to accommodate the requirements of attitude sta- bilization and singularity avoidance of the VSCMG. Illustrative numerical examples verify the efficacy of the proposed control strategy.
基金supported by the National Natural Science Foundation of China (10872029)the Excellent Young Scholars Research Fund of the Beijing Institute of Technology (2007YS0202)
文摘Based on the singular value decomposition theory,this paper analyzed the mechanism of escaping/avoiding singularity using generalized and weighted singularity-robust steering laws for a spacecraft that uses single gimbal control moment gyros （SGCMGs） as the actuator for the attitude control system.The expression of output-torque error is given at the point of singularity,proving the incompatible relationship between the gimbal rate and the output-torque error.The method of establishing a balance between the gimbal rate and the output-torque error is discussed,and a new steering law is designed.Simulation results show that the proposed steering law can effectively drive SGCMGs to escape away from singularities.
文摘针对变速控制力矩陀螺(variable speed control moment gyro,VSCMG)作为执行机构应用在敏捷遥感卫星上进行姿态机动时末端模式切换的平稳性和快速性冲突问题,在考虑框架转速误差的基础上,设计姿态误差参数作为切换指标,制定误差参数切换区域内的过渡规则,将指令力矩实时分配给控制力矩陀螺(control moment gyro,CMG)和飞轮并分别求解,提出了一种控制力矩陀螺/反作用飞轮工作模式模糊平滑切换操纵律。为了使得姿态机动末端卫星姿态达到姿态稳定度和指向精度要求的时间更短,以该时间为优化指标提出聚类变异改进粒子群算法对该操纵律参数寻优,确定最佳的切换区域和切换参数,并进行了仿真验证。结果表明:改进后粒子群算法在相同的迭代次数中总是表现出比传统粒子群算法更优的适应度,具有更快的收敛速度和更高的收敛精度,参数优化后的模糊平滑切换操纵律相比于现有操纵律能够在较短时间内完成双模式的平滑切换,并在姿态机动末端更迅速地达到姿态稳定度和指向精度要求,提高了遥感卫星敏捷机动与高稳指向的控制性能,有利于高质量完成成像任务。
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.
