In this paper,a nonlinear control approach for an unstable networked plant in the presence of actuator and sensor limitations using robust right coprime factorization is proposed.The actuator is limited by upper and l...In this paper,a nonlinear control approach for an unstable networked plant in the presence of actuator and sensor limitations using robust right coprime factorization is proposed.The actuator is limited by upper and lower constraints and the sensor in the feedback loop is subjected to network-induced unknown time-varying delay and noise.With this nonlinear control method,we first employ right coprime factorization based on isomorphism and operator theory to factorize the plant,so that bounded input bounded output(BIBO)stability can be guaranteed.Next,continuous-time generalized predictive control(CGPC)is utilized for the unstable operator of the right coprime factorized plant to guarantee inner stability and enables the closed-loop dynamics of the system with predictive characteristics.Meanwhile,a second-Do F(degrees of freedom)switched controller that satisfies a perturbed Bezout identity and a robustness condition is designed.By using the CGPC controller that possesses predictive behavior and the second-Do F switched stabilizer,the overall stability of the plant subjected to actuator limitations is guaranteed.To address sensor limitations that exist in networked plants in the form of delay and noise which often cause system performance degradation,we implement an identity operator definition in the feedback loop to compensate for these adverse effects.Further,a pre-operator is designed to ensure that the plant output tracks the reference input.Finally,the effectiveness of the proposed design scheme is demonstrated by simulations.展开更多
The robust control issue for uncertain nonlinear system is discussed by using the method of right coprime factorization. As it is difficult to obtain the inverse of the right factor due to the high nonlinearity, the p...The robust control issue for uncertain nonlinear system is discussed by using the method of right coprime factorization. As it is difficult to obtain the inverse of the right factor due to the high nonlinearity, the proving of the Bezout identity becomes troublesome. Therefore, two sufficient conditions are derived to manage this problem with the nonlinear feedback system as well as that with the uncertain nonlinear feedback system under the definition of Lipschitz norm. A simulation of temperature control is given to demonstrate the validity of the proposed method.展开更多
【目的】针对超临界机组燃水比(firing rate to feed water ratio,FR/FW)控制过程中存在强耦合性、负荷量大和抗扰动能力弱等问题,根据自耦PID控制理论提出了自耦PI(auto-coupling PI,ACPI)新型控制方法。【方法】将多变量FR/FW系统等...【目的】针对超临界机组燃水比(firing rate to feed water ratio,FR/FW)控制过程中存在强耦合性、负荷量大和抗扰动能力弱等问题,根据自耦PID控制理论提出了自耦PI(auto-coupling PI,ACPI)新型控制方法。【方法】将多变量FR/FW系统等效为多个单变量闭合回路系统,并将FR/FW系统的耦合性、已知或未知内部动态、外界扰动等一切复杂因素定义为总扰动,进而将FR/FW控制系统等价映射为线性扰动系统,构建了在总扰动激励下的受控误差系统。在此基础上,对每个单变量系统设计了基于速度因子的自耦PI控制器,并在复频域理论分析了控制系统的鲁棒稳定性和抗扰动鲁棒性。【结果】与PI、自抗扰控制方法相比,ACPI控制方法具有响应速度快、无超调的动态品质与抗扰动能力强的稳态性能。【结论】研究成果对提升超临界机组FR/FW系统的控制精度与鲁棒性具有重要意义。展开更多
文摘In this paper,a nonlinear control approach for an unstable networked plant in the presence of actuator and sensor limitations using robust right coprime factorization is proposed.The actuator is limited by upper and lower constraints and the sensor in the feedback loop is subjected to network-induced unknown time-varying delay and noise.With this nonlinear control method,we first employ right coprime factorization based on isomorphism and operator theory to factorize the plant,so that bounded input bounded output(BIBO)stability can be guaranteed.Next,continuous-time generalized predictive control(CGPC)is utilized for the unstable operator of the right coprime factorized plant to guarantee inner stability and enables the closed-loop dynamics of the system with predictive characteristics.Meanwhile,a second-Do F(degrees of freedom)switched controller that satisfies a perturbed Bezout identity and a robustness condition is designed.By using the CGPC controller that possesses predictive behavior and the second-Do F switched stabilizer,the overall stability of the plant subjected to actuator limitations is guaranteed.To address sensor limitations that exist in networked plants in the form of delay and noise which often cause system performance degradation,we implement an identity operator definition in the feedback loop to compensate for these adverse effects.Further,a pre-operator is designed to ensure that the plant output tracks the reference input.Finally,the effectiveness of the proposed design scheme is demonstrated by simulations.
基金supported by the National Natural Science Foundation of China(61304093,61472195)
文摘The robust control issue for uncertain nonlinear system is discussed by using the method of right coprime factorization. As it is difficult to obtain the inverse of the right factor due to the high nonlinearity, the proving of the Bezout identity becomes troublesome. Therefore, two sufficient conditions are derived to manage this problem with the nonlinear feedback system as well as that with the uncertain nonlinear feedback system under the definition of Lipschitz norm. A simulation of temperature control is given to demonstrate the validity of the proposed method.
文摘针对GNSS/INS组合导航进行解算时,容积卡尔曼滤波(cubature Kalman filter,CKF)中状态协方差阵非正定导致滤波发散和观测值异常时组合导航鲁棒性差的问题,本文提出了基于卡方检验改进自适应鲁棒SVDCKF算法。该算法使用奇异值分解(singular value decomposition,SVD)代替CKF中的Cholesky分解,提高了状态协方差矩阵分解迭代的稳定性;利用卡方检验和马氏距离准则构造观测异常检验门限,当观测值异常时通过抗差因子对量测噪声进行调节。车载实测数据实验结果表明,在观测值异常的情况下,该算法的导航定位精度相较于SVDCKF算法和Sage-Husa自适应SVDCKF算法分别提升了27.73%和3.27%,提高了组合导航系统的鲁棒性。
文摘【目的】针对超临界机组燃水比(firing rate to feed water ratio,FR/FW)控制过程中存在强耦合性、负荷量大和抗扰动能力弱等问题,根据自耦PID控制理论提出了自耦PI(auto-coupling PI,ACPI)新型控制方法。【方法】将多变量FR/FW系统等效为多个单变量闭合回路系统,并将FR/FW系统的耦合性、已知或未知内部动态、外界扰动等一切复杂因素定义为总扰动,进而将FR/FW控制系统等价映射为线性扰动系统,构建了在总扰动激励下的受控误差系统。在此基础上,对每个单变量系统设计了基于速度因子的自耦PI控制器,并在复频域理论分析了控制系统的鲁棒稳定性和抗扰动鲁棒性。【结果】与PI、自抗扰控制方法相比,ACPI控制方法具有响应速度快、无超调的动态品质与抗扰动能力强的稳态性能。【结论】研究成果对提升超临界机组FR/FW系统的控制精度与鲁棒性具有重要意义。
