For improving the performance of differential geometric guidance command(DGGC), a new formation of this guidance law is proposed, which can guarantee the finite time convergence(FTC) of the line of sight(LOS) rate to ...For improving the performance of differential geometric guidance command(DGGC), a new formation of this guidance law is proposed, which can guarantee the finite time convergence(FTC) of the line of sight(LOS) rate to zero or its neighborhood against maneuvering targets in three-dimensional(3D) space. The extended state observer(ESO) is employed to estimate the target acceleration, which makes the new DGGC more applicable to practical interception scenarios. Finally, the effectiveness of this newly proposed guidance command is demonstrated by the numerical simulation results.展开更多
The reliability of real-time embedded software directly determines the reliability of the whole real-time embedded sys- tem, and the effective software testing is an important way to ensure software quality and reliab...The reliability of real-time embedded software directly determines the reliability of the whole real-time embedded sys- tem, and the effective software testing is an important way to ensure software quality and reliability. Based on the analysis of the characteristics of real-time embedded software, the formal method is introduced into the real-time embedded software testing field and the real-time extended finite state machine （RT-EFSM） model is studied firstly. Then, the time zone division method of real-time embedded system is presented and the definition and description methods of time-constrained transition equivalence class （timeCTEC） are presented. Furthermore, the approaches of the testing sequence and test case generation are put forward. Finally, the proposed method is applied to a typical avionics real- time embedded software testing practice and the examples of the timeCTEC, testing sequences and test cases are given. With the analysis of the testing result, the application verification shows that the proposed method can effectively describe the real-time embedded software state transition characteristics and real-time requirements and play the advantages of the formal methods in accuracy, effectiveness and the automation supporting. Combined with the testing platform, the real-time, closed loop and automated simulation testing for real-time embedded software can be realized effectively.展开更多
A composited integrated guidance and control(IGC) algorithm is presented to tackle the problem of the IGC design in the dive phase for the bank-to-turn(BTT) vehicle with the inaccuracy information of the line-of-sight...A composited integrated guidance and control(IGC) algorithm is presented to tackle the problem of the IGC design in the dive phase for the bank-to-turn(BTT) vehicle with the inaccuracy information of the line-of-sight(LOS) rate. For the sake of theoretical derivation, an IGC model in the pitch plane is established. The high-order finite-time state observer(FTSO), with the LOS angle as the single input, is employed to reconstruct the states of the system online. Besides, a composited IGC algorithm is presented via the fusion of back-stepping and dynamic inverse. Compared with the traditional IGC algorithm, the proposed composited IGC method can attenuate effectively the design conservation of the flight control system, while the LOS rate is mixed with noise. Extensive experiments have been performed to demonstrate that the proposed approach is globally finite-time stable and strongly robust against parameter uncertainty.展开更多
针对直流微电网中储能系统功率波动、负载侧负荷频繁投切等不确定因素引起母线电压产生波动的问题,以储能系统中三相交错并联双向DC-DC变换器为研究对象,提出一种基于级联有限时间扩张状态观测器(cascade finite-time extended state ob...针对直流微电网中储能系统功率波动、负载侧负荷频繁投切等不确定因素引起母线电压产生波动的问题,以储能系统中三相交错并联双向DC-DC变换器为研究对象,提出一种基于级联有限时间扩张状态观测器(cascade finite-time extended state observer,CFT-ESO)的微分平坦和改进型超螺旋滑模双闭环复合控制策略.首先,建立三相交错并联双向DC-DC变换器的数学模型,并根据微分平坦理论将其直流系统转化为微分平坦系统,结合两级具有快速收敛性的有限时间扩张状态观测器提高对系统集总扰动的估计精度.其次,采用内环微分平坦控制、外环改进型超螺旋滑模控制的双闭环控制系统,既能提高系统动态响应过程,又能利用高阶滑模控制算法抑制抖振,同时解决变换器升压模式中非最小相位问题.再次,通过Lyapunov理论证明控制系统的稳定性.最后,利用MATLAB/Simulink仿真软件以及搭建实验平台对控制策略进行验证,结果表明,本文所提控制策略能够很好地抵抗扰动,提高系统的暂态性能.展开更多
逆变器中死区时间会带来电流谐波和转矩脉动,从而导致感应电机出现明显振动并增加额外损耗。为减少逆变器死区效应带来的不利影响,提出一种基于高阶扩展状态观测器(high-order extended state observer,HO-ESO)的逆变器死区效应在线补...逆变器中死区时间会带来电流谐波和转矩脉动,从而导致感应电机出现明显振动并增加额外损耗。为减少逆变器死区效应带来的不利影响,提出一种基于高阶扩展状态观测器(high-order extended state observer,HO-ESO)的逆变器死区效应在线补偿方法。首先,对逆变器死区效应进行分析,推导出因死区效应而产生的d、q轴误差电压方程。接着,对传统的基于二阶ESO的死区效应补偿方法进行介绍和分析,由分析结果可知,该方法难以准确估计误差电压,从而导致补偿效果欠佳。进一步,设计一种HO-ESO对误差电压进行估计,并将其补偿到感应电机矢量控制系统中。最后,利用仿真和实验测试对所研究的死区效应补偿方法进行验证,并与传统的基于二阶ESO的死区效应补偿法进行对比。测试结果表明,相较于传统基于二阶ESO的死区效应补偿方法,所研究方法表现出更好的死区效应补偿性能。此外,所研究方法无需检测电流极性,易于实施。展开更多
A robust controller for bank to turn(BTT) missiles with aerodynamic fins and reaction jet control system(RCS) is developed based on nonlinear control dynamic models comprising couplings and aerodynamic uncertainties. ...A robust controller for bank to turn(BTT) missiles with aerodynamic fins and reaction jet control system(RCS) is developed based on nonlinear control dynamic models comprising couplings and aerodynamic uncertainties. The fixed time convergence theory is incorporated with the sliding mode control technique to ensure that the system tracks the desired command within uniform bounded time under different initial conditions. Unlike previous terminal sliding mode approaches, the bound of settling time is independent of the initial state, which means performance metrics like convergence rate can be predicted beforehand. To reduce the burden of control design in terms of robustness, extended state observer(ESO) is introduced for uncertainty estimation with the output substituted into the controller as feedforward compensation. Cascade control structure is employed with the proposed control law and therein the compound control signal is obtained.Afterwards, control inputs for two kinds of actuators are allocated on the basis of their inherent characteristics. Finally, a number of simulations are carried out and demonstrate the effectiveness of the designed controller.展开更多
可再生能源的高渗透率给电网供需匹配带来严峻挑战的同时,燃煤机组需要承担着大量的调峰调频任务,这对过热汽温系统的安全稳定运行造成了一定威胁,因此有必要建立面向热工控制的汽温数学模型。考虑到迟延型扩张状态观测器(time-delayed ...可再生能源的高渗透率给电网供需匹配带来严峻挑战的同时,燃煤机组需要承担着大量的调峰调频任务,这对过热汽温系统的安全稳定运行造成了一定威胁,因此有必要建立面向热工控制的汽温数学模型。考虑到迟延型扩张状态观测器(time-delayed extended state observer,TD-ESO)的总扰动信号中含有大量模型信息,提出一种基于ESO补偿模型的参数智能优化和信息提取方法,即以总扰动中未知信息量最小为目标,采用改进沙丘猫算法对模型参数优化并提取总扰动中已知模型信息补偿至ESO的输入端。在仿真算例方面,线性和非线性系统的测试结果表明,所提辨识方法对有无输入迟延的两种系统均有良好的适用性和较高的精度;在实际应用方面,基于超超临界二次再热机组的过热汽温系统数据进行模型辨识与验证,同样表明该建模方法是合理、准确的。因此,该文所建立的模型能够为汽温系统的控制策略设计和性能优化等方面提供有价值的参考。展开更多
文摘For improving the performance of differential geometric guidance command(DGGC), a new formation of this guidance law is proposed, which can guarantee the finite time convergence(FTC) of the line of sight(LOS) rate to zero or its neighborhood against maneuvering targets in three-dimensional(3D) space. The extended state observer(ESO) is employed to estimate the target acceleration, which makes the new DGGC more applicable to practical interception scenarios. Finally, the effectiveness of this newly proposed guidance command is demonstrated by the numerical simulation results.
基金supported by the Aviation Science Foundation of China
文摘The reliability of real-time embedded software directly determines the reliability of the whole real-time embedded sys- tem, and the effective software testing is an important way to ensure software quality and reliability. Based on the analysis of the characteristics of real-time embedded software, the formal method is introduced into the real-time embedded software testing field and the real-time extended finite state machine （RT-EFSM） model is studied firstly. Then, the time zone division method of real-time embedded system is presented and the definition and description methods of time-constrained transition equivalence class （timeCTEC） are presented. Furthermore, the approaches of the testing sequence and test case generation are put forward. Finally, the proposed method is applied to a typical avionics real- time embedded software testing practice and the examples of the timeCTEC, testing sequences and test cases are given. With the analysis of the testing result, the application verification shows that the proposed method can effectively describe the real-time embedded software state transition characteristics and real-time requirements and play the advantages of the formal methods in accuracy, effectiveness and the automation supporting. Combined with the testing platform, the real-time, closed loop and automated simulation testing for real-time embedded software can be realized effectively.
基金supported by the National Natural Science Foundation of China(61627810 61790562 61403096)
文摘A composited integrated guidance and control(IGC) algorithm is presented to tackle the problem of the IGC design in the dive phase for the bank-to-turn(BTT) vehicle with the inaccuracy information of the line-of-sight(LOS) rate. For the sake of theoretical derivation, an IGC model in the pitch plane is established. The high-order finite-time state observer(FTSO), with the LOS angle as the single input, is employed to reconstruct the states of the system online. Besides, a composited IGC algorithm is presented via the fusion of back-stepping and dynamic inverse. Compared with the traditional IGC algorithm, the proposed composited IGC method can attenuate effectively the design conservation of the flight control system, while the LOS rate is mixed with noise. Extensive experiments have been performed to demonstrate that the proposed approach is globally finite-time stable and strongly robust against parameter uncertainty.
文摘针对直流微电网中储能系统功率波动、负载侧负荷频繁投切等不确定因素引起母线电压产生波动的问题,以储能系统中三相交错并联双向DC-DC变换器为研究对象,提出一种基于级联有限时间扩张状态观测器(cascade finite-time extended state observer,CFT-ESO)的微分平坦和改进型超螺旋滑模双闭环复合控制策略.首先,建立三相交错并联双向DC-DC变换器的数学模型,并根据微分平坦理论将其直流系统转化为微分平坦系统,结合两级具有快速收敛性的有限时间扩张状态观测器提高对系统集总扰动的估计精度.其次,采用内环微分平坦控制、外环改进型超螺旋滑模控制的双闭环控制系统,既能提高系统动态响应过程,又能利用高阶滑模控制算法抑制抖振,同时解决变换器升压模式中非最小相位问题.再次,通过Lyapunov理论证明控制系统的稳定性.最后,利用MATLAB/Simulink仿真软件以及搭建实验平台对控制策略进行验证,结果表明,本文所提控制策略能够很好地抵抗扰动,提高系统的暂态性能.
文摘逆变器中死区时间会带来电流谐波和转矩脉动,从而导致感应电机出现明显振动并增加额外损耗。为减少逆变器死区效应带来的不利影响,提出一种基于高阶扩展状态观测器(high-order extended state observer,HO-ESO)的逆变器死区效应在线补偿方法。首先,对逆变器死区效应进行分析,推导出因死区效应而产生的d、q轴误差电压方程。接着,对传统的基于二阶ESO的死区效应补偿方法进行介绍和分析,由分析结果可知,该方法难以准确估计误差电压,从而导致补偿效果欠佳。进一步,设计一种HO-ESO对误差电压进行估计,并将其补偿到感应电机矢量控制系统中。最后,利用仿真和实验测试对所研究的死区效应补偿方法进行验证,并与传统的基于二阶ESO的死区效应补偿法进行对比。测试结果表明,相较于传统基于二阶ESO的死区效应补偿方法,所研究方法表现出更好的死区效应补偿性能。此外,所研究方法无需检测电流极性,易于实施。
基金supported by the National Natural Science Foundation of China(11572036)
文摘A robust controller for bank to turn(BTT) missiles with aerodynamic fins and reaction jet control system(RCS) is developed based on nonlinear control dynamic models comprising couplings and aerodynamic uncertainties. The fixed time convergence theory is incorporated with the sliding mode control technique to ensure that the system tracks the desired command within uniform bounded time under different initial conditions. Unlike previous terminal sliding mode approaches, the bound of settling time is independent of the initial state, which means performance metrics like convergence rate can be predicted beforehand. To reduce the burden of control design in terms of robustness, extended state observer(ESO) is introduced for uncertainty estimation with the output substituted into the controller as feedforward compensation. Cascade control structure is employed with the proposed control law and therein the compound control signal is obtained.Afterwards, control inputs for two kinds of actuators are allocated on the basis of their inherent characteristics. Finally, a number of simulations are carried out and demonstrate the effectiveness of the designed controller.
文摘可再生能源的高渗透率给电网供需匹配带来严峻挑战的同时,燃煤机组需要承担着大量的调峰调频任务,这对过热汽温系统的安全稳定运行造成了一定威胁,因此有必要建立面向热工控制的汽温数学模型。考虑到迟延型扩张状态观测器(time-delayed extended state observer,TD-ESO)的总扰动信号中含有大量模型信息,提出一种基于ESO补偿模型的参数智能优化和信息提取方法,即以总扰动中未知信息量最小为目标,采用改进沙丘猫算法对模型参数优化并提取总扰动中已知模型信息补偿至ESO的输入端。在仿真算例方面,线性和非线性系统的测试结果表明,所提辨识方法对有无输入迟延的两种系统均有良好的适用性和较高的精度;在实际应用方面,基于超超临界二次再热机组的过热汽温系统数据进行模型辨识与验证,同样表明该建模方法是合理、准确的。因此,该文所建立的模型能够为汽温系统的控制策略设计和性能优化等方面提供有价值的参考。
