针对现有MOESP(multiple-input multiple-output output-error state space model identification)和N4SID(numerical algorithm for subspace state space systemidentification)算法在计算状态空间模型系统矩阵(A、B、C、D)时的不足,...针对现有MOESP(multiple-input multiple-output output-error state space model identification)和N4SID(numerical algorithm for subspace state space systemidentification)算法在计算状态空间模型系统矩阵(A、B、C、D)时的不足,提出1种改进的子空间辨识方法。该方法利用MOESP算法可以根据系统观测矩阵直接计算出系统矩阵A和输出矩阵C的优点,先计算矩阵A和C,然后采用N4SID算法计算输入矩阵B和前馈矩阵D。该方法既能够避免MOESP算法在计算矩阵B和D时需要构建大矩阵的缺点,又能避免N4SID算法在计算矩阵A和C时需要求解线性最小二乘的问题,降低了算法的复杂性。将该算法应用于某天然气电站和Alstom气化炉模型的辨识中,通过考核算法的CPU运算时间、CPU浮点数运算次数(floating-pointoperations,FLOPS)和相对误差等指标,将该算法与原有MOESP和N4SID算法进行了比较。计算结果表明,改进的子空间辨识算法能够在保证较好辨识精度的前提下,提高原有算法的计算效率,特别是在大容量数据样本条件下,能够有效降低CPU运算时间和FLOPS。展开更多
提出基于在线递推闭环子空间辨识的模型预测阻尼控制器设计方法。通过辨识获得包含主导低频振荡模式的系统降阶状态空间模型;通过模型预测和优化求解,得到以当前系统状态为初始状态的无限时域的闭环最优控制量。模型辨识和控制量的优化...提出基于在线递推闭环子空间辨识的模型预测阻尼控制器设计方法。通过辨识获得包含主导低频振荡模式的系统降阶状态空间模型;通过模型预测和优化求解,得到以当前系统状态为初始状态的无限时域的闭环最优控制量。模型辨识和控制量的优化求解在有限时间间隔内反复进行。该方法克服了基于离线辨识设计的固定参数控制器的固有缺点,解决了由于运行方式复杂多变和参数的不确定性与时变性引起的控制性能降低问题。8机36节点系统仿真结果表明,控制器可有效地抑制系统的区间低频振荡,并具有与电力系统稳定器(power system stabilizer,PSS)和其他预测阻尼控制器相互协调和适应运行方式变化的能力。展开更多
The on-orbit parameter identification of a space structure can be used for the modification of a system dynamics model and controller coefficients. This study focuses on the estimation of a system state-space model fo...The on-orbit parameter identification of a space structure can be used for the modification of a system dynamics model and controller coefficients. This study focuses on the estimation of a system state-space model for a two-link space manipulator in the procedure of capturing an unknown object, and a recursive tracking approach based on the recursive predictor-based subspace identification(RPBSID) algorithm is proposed to identify the manipulator payload mass parameter. Structural rigid motion and elastic vibration are separated, and the dynamics model of the space manipulator is linearized at an arbitrary working point(i.e., a certain manipulator configuration).The state-space model is determined by using the RPBSID algorithm and matrix transformation. In addition, utilizing the identified system state-space model, the manipulator payload mass parameter is estimated by extracting the corresponding block matrix. In numerical simulations, the presented parameter identification method is implemented and compared with the classical algebraic algorithm and the recursive least squares method for different payload masses and manipulator configurations. Numerical results illustrate that the system state-space model and payload mass parameter of the two-link flexible space manipulator are effectively identified by the recursive subspace tracking method.展开更多
Due to the dynamical character of electromagnetic exciter and the coupling between structure and exciter(s),the actual output force acting on the structure is usually not equal to the exact value that is supposed to b...Due to the dynamical character of electromagnetic exciter and the coupling between structure and exciter(s),the actual output force acting on the structure is usually not equal to the exact value that is supposed to be,especially when multi-exciters are used as actuators to precisely actuate large flexible structure.It is necessary to consider these effects to ensure the force generated by each exciter is the same as required.In this paper,a robust control method is proposed for the multi-input and multi-output(MIMO)structural vibration control system to trace the target actuating force of each exciter.A special signal is designed and put into the coupled mul-ti-exciter-structure system,and the input and output signals of the system are used to build a dynamic model involving both the dynamical characters of the exciters and the structure using the subspace identification method.Considering the uncertainty factors of the multi-exciter/structure system,an H-infinity robust controller is designed to decouple the coupling between structure and exciters based on the identified system model.A MIMO vibration control system combined with a flexible plate and three electromagnetic exciters is adopted to demonstrate the proposed method,both numerical simulation and model experiments showing that the output force of each exciter can trace its target force accurately within the requested frequency band.展开更多
针对非线性CSTR(continuously stirred tank reactor)过程,提出一种新的预测控制的设计与仿真实现。在对一类特殊非线性过程分析的基础上,从系统的输入输出数据出发,基于子空间辨识算法建立双线性系统模型来近似描述被控系统;设计新的...针对非线性CSTR(continuously stirred tank reactor)过程,提出一种新的预测控制的设计与仿真实现。在对一类特殊非线性过程分析的基础上,从系统的输入输出数据出发,基于子空间辨识算法建立双线性系统模型来近似描述被控系统;设计新的预测控制算法实现对CSTR过程的跟踪控制;为补偿模型失配以消除控制中的稳态误差,将积分作用包含在预测控制器的设计中,实现对控制输出的良好跟踪性能;最后通过一个仿真实例验证算法的有效性。展开更多
文摘针对现有MOESP(multiple-input multiple-output output-error state space model identification)和N4SID(numerical algorithm for subspace state space systemidentification)算法在计算状态空间模型系统矩阵(A、B、C、D)时的不足,提出1种改进的子空间辨识方法。该方法利用MOESP算法可以根据系统观测矩阵直接计算出系统矩阵A和输出矩阵C的优点,先计算矩阵A和C,然后采用N4SID算法计算输入矩阵B和前馈矩阵D。该方法既能够避免MOESP算法在计算矩阵B和D时需要构建大矩阵的缺点,又能避免N4SID算法在计算矩阵A和C时需要求解线性最小二乘的问题,降低了算法的复杂性。将该算法应用于某天然气电站和Alstom气化炉模型的辨识中,通过考核算法的CPU运算时间、CPU浮点数运算次数(floating-pointoperations,FLOPS)和相对误差等指标,将该算法与原有MOESP和N4SID算法进行了比较。计算结果表明,改进的子空间辨识算法能够在保证较好辨识精度的前提下,提高原有算法的计算效率,特别是在大容量数据样本条件下,能够有效降低CPU运算时间和FLOPS。
文摘提出基于在线递推闭环子空间辨识的模型预测阻尼控制器设计方法。通过辨识获得包含主导低频振荡模式的系统降阶状态空间模型;通过模型预测和优化求解,得到以当前系统状态为初始状态的无限时域的闭环最优控制量。模型辨识和控制量的优化求解在有限时间间隔内反复进行。该方法克服了基于离线辨识设计的固定参数控制器的固有缺点,解决了由于运行方式复杂多变和参数的不确定性与时变性引起的控制性能降低问题。8机36节点系统仿真结果表明,控制器可有效地抑制系统的区间低频振荡,并具有与电力系统稳定器(power system stabilizer,PSS)和其他预测阻尼控制器相互协调和适应运行方式变化的能力。
基金funded by the National Natural Science Foundation of China (Nos. 11572069 and 51775541)the China Postdoctoral Science Foundation (No. 2016M601354)
文摘The on-orbit parameter identification of a space structure can be used for the modification of a system dynamics model and controller coefficients. This study focuses on the estimation of a system state-space model for a two-link space manipulator in the procedure of capturing an unknown object, and a recursive tracking approach based on the recursive predictor-based subspace identification(RPBSID) algorithm is proposed to identify the manipulator payload mass parameter. Structural rigid motion and elastic vibration are separated, and the dynamics model of the space manipulator is linearized at an arbitrary working point(i.e., a certain manipulator configuration).The state-space model is determined by using the RPBSID algorithm and matrix transformation. In addition, utilizing the identified system state-space model, the manipulator payload mass parameter is estimated by extracting the corresponding block matrix. In numerical simulations, the presented parameter identification method is implemented and compared with the classical algebraic algorithm and the recursive least squares method for different payload masses and manipulator configurations. Numerical results illustrate that the system state-space model and payload mass parameter of the two-link flexible space manipulator are effectively identified by the recursive subspace tracking method.
基金supported by the National Natural Science Foundation of China(Grant Nos.11072198,11102162)111 Project of China(Grant No.B07050)
文摘Due to the dynamical character of electromagnetic exciter and the coupling between structure and exciter(s),the actual output force acting on the structure is usually not equal to the exact value that is supposed to be,especially when multi-exciters are used as actuators to precisely actuate large flexible structure.It is necessary to consider these effects to ensure the force generated by each exciter is the same as required.In this paper,a robust control method is proposed for the multi-input and multi-output(MIMO)structural vibration control system to trace the target actuating force of each exciter.A special signal is designed and put into the coupled mul-ti-exciter-structure system,and the input and output signals of the system are used to build a dynamic model involving both the dynamical characters of the exciters and the structure using the subspace identification method.Considering the uncertainty factors of the multi-exciter/structure system,an H-infinity robust controller is designed to decouple the coupling between structure and exciters based on the identified system model.A MIMO vibration control system combined with a flexible plate and three electromagnetic exciters is adopted to demonstrate the proposed method,both numerical simulation and model experiments showing that the output force of each exciter can trace its target force accurately within the requested frequency band.
文摘针对非线性CSTR(continuously stirred tank reactor)过程,提出一种新的预测控制的设计与仿真实现。在对一类特殊非线性过程分析的基础上,从系统的输入输出数据出发,基于子空间辨识算法建立双线性系统模型来近似描述被控系统;设计新的预测控制算法实现对CSTR过程的跟踪控制;为补偿模型失配以消除控制中的稳态误差,将积分作用包含在预测控制器的设计中,实现对控制输出的良好跟踪性能;最后通过一个仿真实例验证算法的有效性。
