This article mainly investigates the fuzzy optimization robust control issue for nonlinear networked systems characterized by the interval type-2(IT2)fuzzy technique under a differential evolution algorithm.To provide...This article mainly investigates the fuzzy optimization robust control issue for nonlinear networked systems characterized by the interval type-2(IT2)fuzzy technique under a differential evolution algorithm.To provide a more reasonable utilization of the constrained communication channel,a novel adaptive memory event-triggered(AMET)mechanism is developed,where two event-triggered thresholds can be dynamically adjusted in the light of the current system information and the transmitted historical data.Sufficient conditions with less conservative design of the fuzzy imperfect premise matching(IPM)controller are presented by introducing the Wirtinger-based integral inequality,the information of membership functions(MFs)and slack matrices.Subsequently,under the IPM policy,a new MFs intelligent optimization technique that takes advantage of the differential evolution algorithm is first provided for IT2 TakagiSugeno(T-S)fuzzy systems to update the fuzzy controller MFs in real-time and achieve a better system control effect.Finally,simulation results demonstrate that the proposed control scheme can obtain better system performance in the case of using fewer communication resources.展开更多
A neural network control scheme with mixed H2/H∞performance was proposed for robot force/position control under parameter uncertainties and external disturbances. The mixed H2/H∞tracking performance ensures both rob...A neural network control scheme with mixed H2/H∞performance was proposed for robot force/position control under parameter uncertainties and external disturbances. The mixed H2/H∞tracking performance ensures both robust stability under a prescribed attenuation level for external disturbance and H2optimal tracking. The neural network was introduced to adaptively estimate nonlinear uncertainties, improving the system’s performance under parameter uncertainties as well as obtaining the H2/H∞tracking performance. The simulation shows that the control method performs better even when the system is under large modeling uncertainties and external disturbances.展开更多
This paper is concerned with the H2 estimation and control problems for uncertain discretetime systems with norm-bounded parameter uncertainty. We first present an analysis result on H2 norm bound for a stable uncerta...This paper is concerned with the H2 estimation and control problems for uncertain discretetime systems with norm-bounded parameter uncertainty. We first present an analysis result on H2 norm bound for a stable uncertain system in terms of linear matrix inequalities (LMIs). A solution to the robust H2 estimation problem is then derived in terms of two LMIs. As compared to the existing results, our result on robust H2 estimation is more general. In addition, explicit search of appropriate scaling parameters is not needed as the optimization is convex in the scaling parameters. The LMI approach is also extended to solve the robust H2 control problem which has been difficult for the traditional Riccati equation approach since no separation principle has been known for uncertain systems. The design approach is demonstrated through a simple example.展开更多
直流微电网中常常含有恒功率负载(constant power loads,CPLs),其负阻抗特性会降低系统的稳定性,造成直流母线电压波动甚至崩溃。因此,首先建立了直流微电网的小信号模型,使用根轨迹法分析了恒功率负载对系统稳定性的影响;其次提出一种...直流微电网中常常含有恒功率负载(constant power loads,CPLs),其负阻抗特性会降低系统的稳定性,造成直流母线电压波动甚至崩溃。因此,首先建立了直流微电网的小信号模型,使用根轨迹法分析了恒功率负载对系统稳定性的影响;其次提出一种基于混合灵敏度优化的电压控制策略,提升了直流微电网系统的稳定性,并采用改进粒子群优化(particle swarm optimization,PSO)算法对权函数进行了优化,进一步提升了鲁棒控制器的性能;最后采用Matlab/Simulink仿真算例进行验证,仿真结果表明提出的鲁棒控制器减小了母线电压的波动,有效提升了直流微电网系统的稳定性。展开更多
近年来,阻尼力与位移呈线性关系的新型调谐质量阻尼器(Tuned mass damper, TMD)相继出现,其参数分析优化原理大部分属于动力数值分析缺乏理论参数优化指导。该文对白噪声作用下具有上述特性的TMD,即滞变阻尼调谐质量阻尼器(Hysteretic d...近年来,阻尼力与位移呈线性关系的新型调谐质量阻尼器(Tuned mass damper, TMD)相继出现,其参数分析优化原理大部分属于动力数值分析缺乏理论参数优化指导。该文对白噪声作用下具有上述特性的TMD,即滞变阻尼调谐质量阻尼器(Hysteretic damping tuned mass damper, HD-TMD)进行减振优化研究。总结了HD-TMD的力学机理并推导出相应的结构-HD-TMD系统运动方程;提出适用于HD-TMD的H_(2)优化和性能平衡设计,并通过数值拟合技术得到了最优参数公式和基于容忍度的性能平衡设计流程;以真实可用的变摩擦摆式调谐质量阻尼器(VFP-TMD)为HD-TMD的实际算例,检验所提出的优化方法对风振激励的减振性能影响。结果表明:H_(2)优化和性能平衡设计下的HD-TMD可以提供略优于传统黏滞阻尼TMD的控制效果。H_(2)优化的最优参数能使HD-TMD发挥最大的潜能从而实现最好的减振率,但面临VFP-TMD行程过大导致的摆动非线性问题。性能平衡设计下的最优参数可以控制VFP-TMD行程在线性范围内,同时发挥出良好且稳定的减振控制效果实现双赢。与最优参数公式结果相比,性能平衡设计的峰值减振率和均方差峰值减振率仅损失3.19%和0.74%。展开更多
基金supported by the National Natural Science Foundation of China(61973105,62373137)。
文摘This article mainly investigates the fuzzy optimization robust control issue for nonlinear networked systems characterized by the interval type-2(IT2)fuzzy technique under a differential evolution algorithm.To provide a more reasonable utilization of the constrained communication channel,a novel adaptive memory event-triggered(AMET)mechanism is developed,where two event-triggered thresholds can be dynamically adjusted in the light of the current system information and the transmitted historical data.Sufficient conditions with less conservative design of the fuzzy imperfect premise matching(IPM)controller are presented by introducing the Wirtinger-based integral inequality,the information of membership functions(MFs)and slack matrices.Subsequently,under the IPM policy,a new MFs intelligent optimization technique that takes advantage of the differential evolution algorithm is first provided for IT2 TakagiSugeno(T-S)fuzzy systems to update the fuzzy controller MFs in real-time and achieve a better system control effect.Finally,simulation results demonstrate that the proposed control scheme can obtain better system performance in the case of using fewer communication resources.
基金Supported by National High Technology Research and Development Program of China （863 Program） （2006AA04Z183）, National Natural Science Foundation of China （60621001, 60534010, 60572070, 60774048, 60728307）, Program for Changjiang Scholars and Innovative Research Groups of China （60728307, 4031002）
文摘A neural network control scheme with mixed H2/H∞performance was proposed for robot force/position control under parameter uncertainties and external disturbances. The mixed H2/H∞tracking performance ensures both robust stability under a prescribed attenuation level for external disturbance and H2optimal tracking. The neural network was introduced to adaptively estimate nonlinear uncertainties, improving the system’s performance under parameter uncertainties as well as obtaining the H2/H∞tracking performance. The simulation shows that the control method performs better even when the system is under large modeling uncertainties and external disturbances.
文摘This paper is concerned with the H2 estimation and control problems for uncertain discretetime systems with norm-bounded parameter uncertainty. We first present an analysis result on H2 norm bound for a stable uncertain system in terms of linear matrix inequalities (LMIs). A solution to the robust H2 estimation problem is then derived in terms of two LMIs. As compared to the existing results, our result on robust H2 estimation is more general. In addition, explicit search of appropriate scaling parameters is not needed as the optimization is convex in the scaling parameters. The LMI approach is also extended to solve the robust H2 control problem which has been difficult for the traditional Riccati equation approach since no separation principle has been known for uncertain systems. The design approach is demonstrated through a simple example.
文摘直流微电网中常常含有恒功率负载(constant power loads,CPLs),其负阻抗特性会降低系统的稳定性,造成直流母线电压波动甚至崩溃。因此,首先建立了直流微电网的小信号模型,使用根轨迹法分析了恒功率负载对系统稳定性的影响;其次提出一种基于混合灵敏度优化的电压控制策略,提升了直流微电网系统的稳定性,并采用改进粒子群优化(particle swarm optimization,PSO)算法对权函数进行了优化,进一步提升了鲁棒控制器的性能;最后采用Matlab/Simulink仿真算例进行验证,仿真结果表明提出的鲁棒控制器减小了母线电压的波动,有效提升了直流微电网系统的稳定性。
文摘近年来,阻尼力与位移呈线性关系的新型调谐质量阻尼器(Tuned mass damper, TMD)相继出现,其参数分析优化原理大部分属于动力数值分析缺乏理论参数优化指导。该文对白噪声作用下具有上述特性的TMD,即滞变阻尼调谐质量阻尼器(Hysteretic damping tuned mass damper, HD-TMD)进行减振优化研究。总结了HD-TMD的力学机理并推导出相应的结构-HD-TMD系统运动方程;提出适用于HD-TMD的H_(2)优化和性能平衡设计,并通过数值拟合技术得到了最优参数公式和基于容忍度的性能平衡设计流程;以真实可用的变摩擦摆式调谐质量阻尼器(VFP-TMD)为HD-TMD的实际算例,检验所提出的优化方法对风振激励的减振性能影响。结果表明:H_(2)优化和性能平衡设计下的HD-TMD可以提供略优于传统黏滞阻尼TMD的控制效果。H_(2)优化的最优参数能使HD-TMD发挥最大的潜能从而实现最好的减振率,但面临VFP-TMD行程过大导致的摆动非线性问题。性能平衡设计下的最优参数可以控制VFP-TMD行程在线性范围内,同时发挥出良好且稳定的减振控制效果实现双赢。与最优参数公式结果相比,性能平衡设计的峰值减振率和均方差峰值减振率仅损失3.19%和0.74%。
