In this paper a recursive state-space model identification method is proposed for non-uniformly sampled systems in industrial applications. Two cases for measuring all states and only output(s) of such a system are co...In this paper a recursive state-space model identification method is proposed for non-uniformly sampled systems in industrial applications. Two cases for measuring all states and only output(s) of such a system are considered for identification. In the case of state measurement, an identification algorithm based on the singular value decomposition(SVD) is developed to estimate the model parameter matrices by using the least-squares fitting. In the case of output measurement only, another identification algorithm is given by combining the SVD approach with a hierarchical identification strategy. An example is used to demonstrate the effectiveness of the proposed identification method.展开更多
A switching disturbance rejection attitude control law is proposed for a near space vehicle(NSV) with variable structure.The multiple flight modes, system uncertainties and disturbances of the NSV are taken into accou...A switching disturbance rejection attitude control law is proposed for a near space vehicle(NSV) with variable structure.The multiple flight modes, system uncertainties and disturbances of the NSV are taken into account based on switched nonlinear systems. Compared with traditional backstepping design methods,the proposed method utilizes the added integrals of attitude angle and angular rate tracking errors to further decrease the tracking errors. Moreover, to reduce the computation complexity, a rapid convergent differentiator is employed to obtain the derivative of the virtual control command. Finally, for disturbance rejection, based on the idea from the extended state observer(ESO), two disturbance observers are designed by using non-smooth functions to estimate the disturbances in the switched nonlinear systems. All signals of the closed-loop system are proven to be uniformly ultimately bounded under the Lyapunov function framework. Simulation results demonstrate the effectiveness of the proposed control scheme.展开更多
在型谐振感应电能传输(inductive power transfer,IPT)系统中,由于负载及耦合参数变化,导致系统谐振频率产生随机漂移。针对频率不确定条件下的输出控制,利用广义状态空间平均(generalized state space averaging,GSSA)法对系统进行频...在型谐振感应电能传输(inductive power transfer,IPT)系统中,由于负载及耦合参数变化,导致系统谐振频率产生随机漂移。针对频率不确定条件下的输出控制,利用广义状态空间平均(generalized state space averaging,GSSA)法对系统进行频域建模,将状态变量进行频域展开获得广义状态变量,从而获得线性状态空间模型。借助线性分式变换,将GSSA模型的确定部分与不确定部分分离,从而将系统的不确定模型转化为含摄动反馈的线性动力学系统。在此基础上提出一种基于GSSA模型的H_∞控制方法,又基于频域设计出混合灵敏度H_∞控制器,实现了多变量无静差跟踪鲁棒控制,并利用结构奇异值分析方法校验了鲁棒控制器的稳定性及性能。仿真及实验结果验证了其可行性。展开更多
基金Supported in part by the National Thousand Talents Program of Chinathe National Natural Science Foundation of China(61473054)the Fundamental Research Funds for the Central Universities of China
文摘In this paper a recursive state-space model identification method is proposed for non-uniformly sampled systems in industrial applications. Two cases for measuring all states and only output(s) of such a system are considered for identification. In the case of state measurement, an identification algorithm based on the singular value decomposition(SVD) is developed to estimate the model parameter matrices by using the least-squares fitting. In the case of output measurement only, another identification algorithm is given by combining the SVD approach with a hierarchical identification strategy. An example is used to demonstrate the effectiveness of the proposed identification method.
基金supported by the National Natural Science Foundation of China(61374012)the Aeronautical Science Foundation of China(2016ZA51011)
文摘A switching disturbance rejection attitude control law is proposed for a near space vehicle(NSV) with variable structure.The multiple flight modes, system uncertainties and disturbances of the NSV are taken into account based on switched nonlinear systems. Compared with traditional backstepping design methods,the proposed method utilizes the added integrals of attitude angle and angular rate tracking errors to further decrease the tracking errors. Moreover, to reduce the computation complexity, a rapid convergent differentiator is employed to obtain the derivative of the virtual control command. Finally, for disturbance rejection, based on the idea from the extended state observer(ESO), two disturbance observers are designed by using non-smooth functions to estimate the disturbances in the switched nonlinear systems. All signals of the closed-loop system are proven to be uniformly ultimately bounded under the Lyapunov function framework. Simulation results demonstrate the effectiveness of the proposed control scheme.
文摘在型谐振感应电能传输(inductive power transfer,IPT)系统中,由于负载及耦合参数变化,导致系统谐振频率产生随机漂移。针对频率不确定条件下的输出控制,利用广义状态空间平均(generalized state space averaging,GSSA)法对系统进行频域建模,将状态变量进行频域展开获得广义状态变量,从而获得线性状态空间模型。借助线性分式变换,将GSSA模型的确定部分与不确定部分分离,从而将系统的不确定模型转化为含摄动反馈的线性动力学系统。在此基础上提出一种基于GSSA模型的H_∞控制方法,又基于频域设计出混合灵敏度H_∞控制器,实现了多变量无静差跟踪鲁棒控制,并利用结构奇异值分析方法校验了鲁棒控制器的稳定性及性能。仿真及实验结果验证了其可行性。
