For a class of linear discrete-time systems that is subject to randomly occurred networked packet loss in industrial cyber physical systems, a novel robust model predictive control method with active compensation mech...For a class of linear discrete-time systems that is subject to randomly occurred networked packet loss in industrial cyber physical systems, a novel robust model predictive control method with active compensation mechanism was proposed. The probability distribution of packet loss is described as the Bernoulli distributed white sequences. By using the Lyapunov stability theory, the existing sufficient conditions of the controller are derived from solving a group of linear matrix inequalities. Moreover, dropout-rate with uncertainty and unknown dropout-rate are also considered, which can greatly reduce the conservativeness of the controller. The designed robust model predictive control method not only efficiently eliminates the negative effects of the networked data loss in industrial cyber physical systems but also ensures the stability of closed-loop system. Two examples were provided to illustrate the superiority and effectiveness of the proposed method.展开更多
A new hierarchical switching control system of multiple models based on robust control theory is designed for some plant with large uncertainties. The model set and controller set are designed by robust control theory...A new hierarchical switching control system of multiple models based on robust control theory is designed for some plant with large uncertainties. The model set and controller set are designed by robust control theory and the characteristics of robust control system are taken into account. A new kind of switching index function by estimating uncertainty is designed. Furthermore, stability of the closed system is analyzed by the small gain theorem in the sense of exponentially weighted L2 norm. And simulation is done on a plant with both parameter uncertainty and un-modeled dynamics. Both theoretical analysis and simulation results show that this new hierarchical switching control system can control the plant with large uncertainties effectively and has good performance of tracking and stability.展开更多
The problem of controlling a single-input-single-output plant without prior knowledge of high frequency gain sign is addressed by using the model reference robust control approach.A switching method is proposed based ...The problem of controlling a single-input-single-output plant without prior knowledge of high frequency gain sign is addressed by using the model reference robust control approach.A switching method is proposed based on a monitoring function so that after a finite number of swi- tchings the tracking error converges to zero exponentially.Furthermore,it is shown that if some initial states of the closed-loop system are zero,only one switching is needed.展开更多
The thermal induced errors can account for as much as 70% of the dimensional errors on a workpiece. Accurate modeling of errors is an essential part of error compensation. Base on analyzing the existing approaches of ...The thermal induced errors can account for as much as 70% of the dimensional errors on a workpiece. Accurate modeling of errors is an essential part of error compensation. Base on analyzing the existing approaches of the thermal error modeling for machine tools, a new approach of regression orthogonal design is proposed, which combines the statistic theory with machine structures, surrounding condition, engineering judgements, and experience in modeling. A whole computation and analysis procedure is given. Therefore, the model got from this method are more robust and practical than those got from the present method that depends on the modeling data completely. At last more than 100 applications of CNC turning center with only one thermal error model are given. The cutting diameter variation reduces from more than 35 μm to about 12 μm with the orthogonal regression modeling and compensation of thermal error.展开更多
Reduction of conservatism is one of the key and difficult problems in missile robust gain scheduling autopilot design based on multipliers.This article presents a scheme of adopting linear parameter-varying（LPV） con...Reduction of conservatism is one of the key and difficult problems in missile robust gain scheduling autopilot design based on multipliers.This article presents a scheme of adopting linear parameter-varying（LPV） control approach with full block multipliers to design a missile robust gain scheduling autopilot in order to eliminate conservatism.A model matching design structure with a high demand on matching precision is constructed based on the missile linear fractional transformation（LFT） model.By applying full block S-procedure and elimination lemma,a convex feasibility problem with an infinite number of constraints is formulated to satisfy robust quadratic performance specifications.Then a grid method is adopted to transform the infinite-dimensional convex feasibility problem into a solvable finite-dimensional convex feasibility problem,based on which a gain scheduling controller with linear fractional dependence on the flight Mach number and altitude is derived.Static and dynamic simulation results show the effectiveness and feasibility of the proposed scheme.展开更多
The traditional deadbeat control for UPS inverters has a robustness problem. The parametric imprecision can greatly harm the stability of the system, which restricts the application. A novel robust deadbeat control me...The traditional deadbeat control for UPS inverters has a robustness problem. The parametric imprecision can greatly harm the stability of the system, which restricts the application. A novel robust deadbeat control method is proposed in this paper to deal with the problem. In the proposed control method, a proportional element is added to the traditional deadbeat control in order to improve the robustness to parametric imprecision. To eliminate the error between output voltage and voltage reference caused by environmental noise and parametric deviation, a model reference adaptive regulator is also added to the control method. A 1kVA prototype is built based on DSP. Theoretical analysis and experimental results show that the robustness for parametric variation of the proposed method is much better than the traditional deadbeat control. The system can remain stable even when the systemic parameters have a large deviation from calculating parameters. The system has small static error and fast dynamic response with the new control method. This method is easy to realize in DSP and is suitable for full digital realization of UPS.展开更多
For regulating the dynamic nonholonomic mobile cart with parameter uncertainties, a time-varying robust control law is derived to yield globally exponential convergence of cart's position and orientation to the de...For regulating the dynamic nonholonomic mobile cart with parameter uncertainties, a time-varying robust control law is derived to yield globally exponential convergence of cart's position and orientation to the desired set point. The controller design relies on converting the cart's dynamics to an advantageous form, and the robust linear feedback control laws steer the cart's position and orientation errors to zero exponentially. Simulation results show the effectiveness of the proposed control law.展开更多
A simple PI controller tuning method for large dead-time processes is presented. First, a first-order plus dead-time model is identified on the basis of relay feedback experiments, which Nyquist curve is very close to...A simple PI controller tuning method for large dead-time processes is presented. First, a first-order plus dead-time model is identified on the basis of relay feedback experiments, which Nyquist curve is very close to that of large dead-time processes over a wide frequency range. With the model available, PI controller is designed with a new robust specification. Simulation examples show the effectiveness and feasibility of the presented PI tuning method for large dead-time processes.展开更多
In this paper, we shall summarize a new approach to robust and fault tolerant control proposed recently by the author. This approach is based on a variation of all controller parametrization. This robust and fault-tol...In this paper, we shall summarize a new approach to robust and fault tolerant control proposed recently by the author. This approach is based on a variation of all controller parametrization. This robust and fault-tolerant control design consists of two parts: a nominal performance controller and a robustness controller, and works in such a way that when a component (sensor,actuator, etc.) failure is detected, the controller structure is reconfigured by adding a robustness loop to compensate the fault. We shall illustrate how this strategy works under various situations.展开更多
为了解决高比例分布式电源(distributed generation,DG)大规模并网后实时量测数目缺失、传统预测辅助状态估计方法(forecasting-aided state estimation,FASE)估计精度有限等问题,提出了基于改进Crossformer伪量测构建的主动配电网FASE...为了解决高比例分布式电源(distributed generation,DG)大规模并网后实时量测数目缺失、传统预测辅助状态估计方法(forecasting-aided state estimation,FASE)估计精度有限等问题,提出了基于改进Crossformer伪量测构建的主动配电网FASE方法。首先,基于最大信息系数法(maximal information coefficient,MIC)筛选出高相关性的输入特征,提高预测模型的精度;然后,通过全变差正则化技术(total variation regularized,TV)优化鲁棒主成分分析法(robust principal component analysis,RPCA),构建TRPCA层,并将其嵌入到Crossformer中,以填补Crossformer无法有效处理非高斯噪声的空白;最后,利用改进的预测模型进行超短期负荷预测,经潮流计算得到节点伪量测,在量测不足情况下补全缺失数据,并结合扩展卡尔曼滤波器(extended Kalman filter,EKF)进行状态估计。在IEEE 33节点和IEEE 118节点标准配电网上进行仿真测试,结果表明所提方法在估计精度和鲁棒性等方面具有一定优势,可为主动配电网FASE提供参考。展开更多
A robust attitude controller for hydrofoil catamaran throughout its operating envelope is proposed, based on Tagaki-Sugeno (T-S) fuzzy model. Firstly, T-S fuzzy model and robust attitude control strategy for hydrofoil...A robust attitude controller for hydrofoil catamaran throughout its operating envelope is proposed, based on Tagaki-Sugeno (T-S) fuzzy model. Firstly, T-S fuzzy model and robust attitude control strategy for hydrofoil catamaran is presented by use of linear matrix inequality (LMI) techniques. Secondly, a nonlinear mathematical model of hydrofoil catamaran is established, acting as the platform for further researches. The specialty in interpolation of T-S fuzzy model guarantees that feedback gain can be obtained smoothly, while boat's speed is shifting over the operating envelope. The external disturbances are also attenuated to achieve H ∞ control performance, meanwhile. Finally, based on such a boat, HC200B-A1, simulation researches demonstrate the design procedures and the effectiveness of fuzzy robust attitude controller.展开更多
基金Project(61673199)supported by the National Natural Science Foundation of ChinaProject(ICT1800400)supported by the Open Research Project of the State Key Laboratory of Industrial Control Technology,Zhejiang University,China
文摘For a class of linear discrete-time systems that is subject to randomly occurred networked packet loss in industrial cyber physical systems, a novel robust model predictive control method with active compensation mechanism was proposed. The probability distribution of packet loss is described as the Bernoulli distributed white sequences. By using the Lyapunov stability theory, the existing sufficient conditions of the controller are derived from solving a group of linear matrix inequalities. Moreover, dropout-rate with uncertainty and unknown dropout-rate are also considered, which can greatly reduce the conservativeness of the controller. The designed robust model predictive control method not only efficiently eliminates the negative effects of the networked data loss in industrial cyber physical systems but also ensures the stability of closed-loop system. Two examples were provided to illustrate the superiority and effectiveness of the proposed method.
基金Supported by National Natural Science Foundation of China （60504026, 60674041） and National High Technology Research and Development Program of China （863 Program）（2006AA04Z173）.
基金Supported by National Key Program of Technology (2002BA404A21)
文摘A new hierarchical switching control system of multiple models based on robust control theory is designed for some plant with large uncertainties. The model set and controller set are designed by robust control theory and the characteristics of robust control system are taken into account. A new kind of switching index function by estimating uncertainty is designed. Furthermore, stability of the closed system is analyzed by the small gain theorem in the sense of exponentially weighted L2 norm. And simulation is done on a plant with both parameter uncertainty and un-modeled dynamics. Both theoretical analysis and simulation results show that this new hierarchical switching control system can control the plant with large uncertainties effectively and has good performance of tracking and stability.
基金Supported by National Natural Science Foundation of P.R.China(60174001)National Natural Science Foundation of Beijing(4022007)
文摘The problem of controlling a single-input-single-output plant without prior knowledge of high frequency gain sign is addressed by using the model reference robust control approach.A switching method is proposed based on a monitoring function so that after a finite number of swi- tchings the tracking error converges to zero exponentially.Furthermore,it is shown that if some initial states of the closed-loop system are zero,only one switching is needed.
文摘The thermal induced errors can account for as much as 70% of the dimensional errors on a workpiece. Accurate modeling of errors is an essential part of error compensation. Base on analyzing the existing approaches of the thermal error modeling for machine tools, a new approach of regression orthogonal design is proposed, which combines the statistic theory with machine structures, surrounding condition, engineering judgements, and experience in modeling. A whole computation and analysis procedure is given. Therefore, the model got from this method are more robust and practical than those got from the present method that depends on the modeling data completely. At last more than 100 applications of CNC turning center with only one thermal error model are given. The cutting diameter variation reduces from more than 35 μm to about 12 μm with the orthogonal regression modeling and compensation of thermal error.
文摘Reduction of conservatism is one of the key and difficult problems in missile robust gain scheduling autopilot design based on multipliers.This article presents a scheme of adopting linear parameter-varying（LPV） control approach with full block multipliers to design a missile robust gain scheduling autopilot in order to eliminate conservatism.A model matching design structure with a high demand on matching precision is constructed based on the missile linear fractional transformation（LFT） model.By applying full block S-procedure and elimination lemma,a convex feasibility problem with an infinite number of constraints is formulated to satisfy robust quadratic performance specifications.Then a grid method is adopted to transform the infinite-dimensional convex feasibility problem into a solvable finite-dimensional convex feasibility problem,based on which a gain scheduling controller with linear fractional dependence on the flight Mach number and altitude is derived.Static and dynamic simulation results show the effectiveness and feasibility of the proposed scheme.
文摘The traditional deadbeat control for UPS inverters has a robustness problem. The parametric imprecision can greatly harm the stability of the system, which restricts the application. A novel robust deadbeat control method is proposed in this paper to deal with the problem. In the proposed control method, a proportional element is added to the traditional deadbeat control in order to improve the robustness to parametric imprecision. To eliminate the error between output voltage and voltage reference caused by environmental noise and parametric deviation, a model reference adaptive regulator is also added to the control method. A 1kVA prototype is built based on DSP. Theoretical analysis and experimental results show that the robustness for parametric variation of the proposed method is much better than the traditional deadbeat control. The system can remain stable even when the systemic parameters have a large deviation from calculating parameters. The system has small static error and fast dynamic response with the new control method. This method is easy to realize in DSP and is suitable for full digital realization of UPS.
基金Supported by National Natural Science Foundation of P. R. China (60274005, 60334030)
文摘For regulating the dynamic nonholonomic mobile cart with parameter uncertainties, a time-varying robust control law is derived to yield globally exponential convergence of cart's position and orientation to the desired set point. The controller design relies on converting the cart's dynamics to an advantageous form, and the robust linear feedback control laws steer the cart's position and orientation errors to zero exponentially. Simulation results show the effectiveness of the proposed control law.
基金This project was support by the National "863" High-Tech Research and Development Foundation (2001AA413130).
文摘A simple PI controller tuning method for large dead-time processes is presented. First, a first-order plus dead-time model is identified on the basis of relay feedback experiments, which Nyquist curve is very close to that of large dead-time processes over a wide frequency range. With the model available, PI controller is designed with a new robust specification. Simulation examples show the effectiveness and feasibility of the presented PI tuning method for large dead-time processes.
基金Supported in part by grants from NASA and the Louisiana Board of Regents
文摘In this paper, we shall summarize a new approach to robust and fault tolerant control proposed recently by the author. This approach is based on a variation of all controller parametrization. This robust and fault-tolerant control design consists of two parts: a nominal performance controller and a robustness controller, and works in such a way that when a component (sensor,actuator, etc.) failure is detected, the controller structure is reconfigured by adding a robustness loop to compensate the fault. We shall illustrate how this strategy works under various situations.
文摘为了解决高比例分布式电源(distributed generation,DG)大规模并网后实时量测数目缺失、传统预测辅助状态估计方法(forecasting-aided state estimation,FASE)估计精度有限等问题,提出了基于改进Crossformer伪量测构建的主动配电网FASE方法。首先,基于最大信息系数法(maximal information coefficient,MIC)筛选出高相关性的输入特征,提高预测模型的精度;然后,通过全变差正则化技术(total variation regularized,TV)优化鲁棒主成分分析法(robust principal component analysis,RPCA),构建TRPCA层,并将其嵌入到Crossformer中,以填补Crossformer无法有效处理非高斯噪声的空白;最后,利用改进的预测模型进行超短期负荷预测,经潮流计算得到节点伪量测,在量测不足情况下补全缺失数据,并结合扩展卡尔曼滤波器(extended Kalman filter,EKF)进行状态估计。在IEEE 33节点和IEEE 118节点标准配电网上进行仿真测试,结果表明所提方法在估计精度和鲁棒性等方面具有一定优势,可为主动配电网FASE提供参考。
文摘A robust attitude controller for hydrofoil catamaran throughout its operating envelope is proposed, based on Tagaki-Sugeno (T-S) fuzzy model. Firstly, T-S fuzzy model and robust attitude control strategy for hydrofoil catamaran is presented by use of linear matrix inequality (LMI) techniques. Secondly, a nonlinear mathematical model of hydrofoil catamaran is established, acting as the platform for further researches. The specialty in interpolation of T-S fuzzy model guarantees that feedback gain can be obtained smoothly, while boat's speed is shifting over the operating envelope. The external disturbances are also attenuated to achieve H ∞ control performance, meanwhile. Finally, based on such a boat, HC200B-A1, simulation researches demonstrate the design procedures and the effectiveness of fuzzy robust attitude controller.
