Complexity is one of the leading features of modem control systems. It is caused by the complex properties of controlled plants and the varied requirements in controller designs. In dealing with the control problems w...Complexity is one of the leading features of modem control systems. It is caused by the complex properties of controlled plants and the varied requirements in controller designs. In dealing with the control problems with complexity, in the past two decades, a lot of papers have been published that reported fruitful results on different theoretical backgrounds and with different methodologies, such as differential geometry-based design methods, hybrid system theory, switching control, neural network-based intelligent control, etc.展开更多
Because of limited resource of embedded platforms, the computational complexity of advanced control algorithms raises significant challenges for the use of embedded systems in complex control field. A Scilab/Scicos ba...Because of limited resource of embedded platforms, the computational complexity of advanced control algorithms raises significant challenges for the use of embedded systems in complex control field. A Scilab/Scicos based embedded controller is developed on which various control software can be easily modeled, simulated, implemented, and evaluated to meet the ever-expanding requirements of industrial control applications. Built on the Cirrus Logic EP9315 ARM systems-on-chip board, this embedded controller is possible to develop complex embedded control systems that employ advanced control strategies in a rapid and cost-efficient fashion. Due to the free and open source nature of the software packages used, the cost of the embedded controller is minimized.展开更多
In this paper, the naturally evolving complex systems, such as biotic and social ones, are considered. Focusing on their structures, a feature is noteworthy, i.e., the similarity in structures. The relations between t...In this paper, the naturally evolving complex systems, such as biotic and social ones, are considered. Focusing on their structures, a feature is noteworthy, i.e., the similarity in structures. The relations between the functions and behaviors of these systems and their similar structures will be studied. Owing to the management of social systems and the course of evolution of biotic systems may be regarded as control processes, the researches will be within the scope of control problems. Moreover, since it is difficult to model for biotic and social systems, it will start with the control problems of complex systems, possessing similar structures, in engineering. The obtained results show that for either linear or nonlinear systems and for a lot of control problems similar structures lead to a series of simplifications. In general, the original system may be decomposed into reduced amount of subsystems with lower dimensions and simpler structures. By virtue of such subsystems, the control problems of original system can be solved more simply. At last, it turns round to observe the biotic and social systems and some analyses are given.展开更多
The complexity of linear, fixed-point arithmetic digital controllers is investigated from a Kolmogorov-Chaitin perspective. Based on the idea of Kolmogorov-Chaitin complexity, practical measures of complexity are deve...The complexity of linear, fixed-point arithmetic digital controllers is investigated from a Kolmogorov-Chaitin perspective. Based on the idea of Kolmogorov-Chaitin complexity, practical measures of complexity are developed for statespace realizations, parallel and cascade realizations, and for a newly proposed generalized implicit state-space realization. The complexity of solutions to a restricted complexity controller benchmark problem is investigated using this measure. The results show that from a Kolmogorov-Chaitin viewpoint, higher-order controllers with a shorter word-length may have lower complexity and better performance, than lower-order controllers with longer word-length.展开更多
In this paper, the complexity of intra coding is first analyzed so as to achieve a weight of complexity measurement for each intra mode. Then, a new complexity scalable control algorithm for intra coding in H. 264 is ...In this paper, the complexity of intra coding is first analyzed so as to achieve a weight of complexity measurement for each intra mode. Then, a new complexity scalable control algorithm for intra coding in H. 264 is proposed, based on the rearrangement of the order of candidate modes and an efficient complexity allocation and control (CAAC) scheme at the macroblock (MB) level. The candidate modes of each MB are rearranged according to the local-edge information. Experimental results show that our proposed algorithm can make an appropriate cut-off point of the candidate modes sequence adaptively according to the current energy condition of a mobile device, so as to adjust the complexity at any level while maximizing the video quality, which can prolong the operational lifetime of the battery with minimum degradation in video quality.展开更多
With the Rio Olympics just a few months past,we remember the excitement,the incredible performances,and the controversies.As happens so often,the Olympic Games focus attention not only on athletic achievements but als...With the Rio Olympics just a few months past,we remember the excitement,the incredible performances,and the controversies.As happens so often,the Olympic Games focus attention not only on athletic achievements but also on how athletes may reach ever-increasing levels of performance.Doping,medical展开更多
The dual three-phase PMSM(DTP-PMSM)drives have received wide attention at high-power high-efficiency applications due to their merits of high output current ability and copper-loss-free field excitation.Meanwhile,the ...The dual three-phase PMSM(DTP-PMSM)drives have received wide attention at high-power high-efficiency applications due to their merits of high output current ability and copper-loss-free field excitation.Meanwhile,the DTPPMSM drive provides higher fault-tolerant capability for highreliability applications,e.g.,pumps and actuators in aircraft.For high-power drives with limited switching frequencies and highspeed drives with large fundamental frequencies,the ratio of switching frequency to fundamental frequency,i.e.,the carrier ratio,is usually below 15,which would significantly degrade the control performance.The purpose of this paper is to review the recent work on the modulation and control schemes for improving the operation performance of DTP-PMSM drives with low carrier ratios.Specifically,three categories of methods,i.e.,the space vector modulation based control,the model predictive control(MPC),and the optimized pulse pattern(OPP)based control are reviewed with principles and performance.In addition,brief discussions regarding the comparison and future trends are presented for low-carrier-ratio(LCR)modulation and control schemes of DTP-PMSM drives.展开更多
The stabilization properties of various typical complex dynamical networks composed of chaotic nodes are theoretically investigated and numerically simulated in detail. Some local stability properties of such pinned n...The stabilization properties of various typical complex dynamical networks composed of chaotic nodes are theoretically investigated and numerically simulated in detail. Some local stability properties of such pinned networks are derived and the valid stability regions are estimated based on eigenvalue analysis. Numerical simulations of such networks are given to explain why significantly less local controllers are needed by the specifically pinning scheme, which pins the most highly connected nodes in scale-free networks, than that required by the randomly pinning scheme. Also, it is explained why there is no significant difference between the two schemes for controlling random-graph networks and small-world networks.展开更多
The Brazilian electric sector reform established that the remuneration of distribution utilities must be through the management of their systems. This fact increased the necessity of control and management of load flo...The Brazilian electric sector reform established that the remuneration of distribution utilities must be through the management of their systems. This fact increased the necessity of control and management of load flows through the connection points between the distribution systems and the basic grid as a function of the contracted amounts. The objective of this control is to avoid that these flows exceed some thresholds along the contracted values, avoiding monetary penalties to the utility or unnecessary amounts of contracted flows that overrates the costumers. This question highlights the necessity of forecast the flows in these connection points in sufficient time to permit the operator to take decisions to avoid flows beyond the contracted ones. In this context, this work presents the development of a neural network based load flow forecaster, being tested two time-series neural models: support vector machines and Bayesian inference applied to multilayered perceptron. The models are applied to real data from a Brazilian distribution utility.展开更多
In this paper, a real-time computation method for the control problems in differential-algebraic systems is presented. The errors of the method are estimated, and the relation between the sampling stepsize and the con...In this paper, a real-time computation method for the control problems in differential-algebraic systems is presented. The errors of the method are estimated, and the relation between the sampling stepsize and the controlled errors is analyzed. The stability analysis is done for a model problem, and the stability region is ploted which gives the range of the sampling stepsizes with which the stability of control process is guaranteed.展开更多
A complex autonomous inventory coupled system is considered. It can take, for example, the form of a network of chemical or biochemical reactors, where the inventory interactions perform the recycling of by-products b...A complex autonomous inventory coupled system is considered. It can take, for example, the form of a network of chemical or biochemical reactors, where the inventory interactions perform the recycling of by-products between the subsystems. Because of the flexible subsystems interactions, each of them can be operated with their own periods utilizing advantageously their dynamic properties. A multifrequency second-order test generalizing the p-test for single systems is described. It can be used to decide which kind of the operation (the static one, the periodic one or the multiperiodic one) will intensify the productivity of a complex system. An illustrative example of the multiperiodic optimization of a complex chemical production system is presented.展开更多
Stability criteria for the complex-valued impulsive system are applied widely in many fields, such as quantum systems, which have been studied in recent decades. In this paper, I investigate the Lyapunov control of fi...Stability criteria for the complex-valued impulsive system are applied widely in many fields, such as quantum systems, which have been studied in recent decades. In this paper, I investigate the Lyapunov control of finite dimensional complex-valued systems with impulsive control fields, where the studied complex-valued systems are governed by the Schrödinger equation and can be used in quantum systems. By one Lyapunov function based on state error and the invariant principle of impulsive systems, I study the convergence of complex-valued systems with impulsive control fields and propose new results for the mentioned complex-valued systems in the form of sufficient conditions. A numerical simulation to validate the proposed control method is provided.展开更多
The aim of this paper is to study complex modified projective synchronization(CMPS) between fractional-order chaotic nonlinear systems with incommensurate orders. Based on the stability theory of incommensurate frac...The aim of this paper is to study complex modified projective synchronization(CMPS) between fractional-order chaotic nonlinear systems with incommensurate orders. Based on the stability theory of incommensurate fractional-order systems and active control method, control laws are derived to achieve CMPS in three situations including fractional-order complex Lorenz system driving fractional-order complex Chen system, fractional-order real Rssler system driving fractional-order complex Chen system, and fractionalorder complex Lorenz system driving fractional-order real Lü system. Numerical simulations confirm the validity and feasibility of the analytical method.展开更多
针对系统理论过程分析(STPA,systems-theoretic process analysis)在民机机载系统安全性分析中存在的局限性,首先,本文基于复杂网络理论将控制结构模型转化为致因传播网络,以出入度等参数反映信息交互和致因传播情况,实现系统故障的关...针对系统理论过程分析(STPA,systems-theoretic process analysis)在民机机载系统安全性分析中存在的局限性,首先,本文基于复杂网络理论将控制结构模型转化为致因传播网络,以出入度等参数反映信息交互和致因传播情况,实现系统故障的关键部件定位,从而进行针对性防控。其次,针对STPA方法,从安全性需求捕获、安全性验证、关键致因识别3个方面提出改进,完善系统安全性评估确认与验证过程。最后,以襟翼控制系统为应用对象,验证该方法的可行性和有效性,可为复杂机载系统提供一种系统的安全性分析思路。展开更多
Air traffic complexity is an objective metric for evaluating the operational condition of the airspace. It has several applications, such as airspace design and traffic flow management.Therefore, identifying a reliabl...Air traffic complexity is an objective metric for evaluating the operational condition of the airspace. It has several applications, such as airspace design and traffic flow management.Therefore, identifying a reliable method to accurately measure traffic complexity is important. Considering that many factors correlate with traffic complexity in complicated nonlinear ways,researchers have proposed several complexity evaluation methods based on machine learning models which were trained with large samples. However, the high cost of sample collection usually results in limited training set. In this paper, an ensemble learning model is proposed for measuring air traffic complexity within a sector based on small samples. To exploit the classification information within each factor, multiple diverse factor subsets(FSSs) are generated under guidance from factor noise and independence analysis. Then, a base complexity evaluator is built corresponding to each FSS. The final complexity evaluation result is obtained by integrating all results from the base evaluators. Experimental studies using real-world air traffic operation data demonstrate the advantages of our model for small-sample-based traffic complexity evaluation over other stateof-the-art methods.展开更多
摘要Complexity is one of the leading features of modem control systems. It is caused by the complex properties of controlled plants and the varied requirements in controller designs. In dealing with the control problems with complexity, in the past two decades, a lot of papers have been published that reported fruitful results on different theoretical backgrounds and with different methodologies, such as differential geometry-based design methods, hybrid system theory, switching control, neural network-based intelligent control, etc.
基金supported in part by the National Natural Science Foundation under Grant No.61070003,No.61272020,and No.61071128Zhejiang Provincial Natural Science Foundation under Grant No.R1090052 and No.Y1101184
摘要Because of limited resource of embedded platforms, the computational complexity of advanced control algorithms raises significant challenges for the use of embedded systems in complex control field. A Scilab/Scicos based embedded controller is developed on which various control software can be easily modeled, simulated, implemented, and evaluated to meet the ever-expanding requirements of industrial control applications. Built on the Cirrus Logic EP9315 ARM systems-on-chip board, this embedded controller is possible to develop complex embedded control systems that employ advanced control strategies in a rapid and cost-efficient fashion. Due to the free and open source nature of the software packages used, the cost of the embedded controller is minimized.
摘要In this paper, the naturally evolving complex systems, such as biotic and social ones, are considered. Focusing on their structures, a feature is noteworthy, i.e., the similarity in structures. The relations between the functions and behaviors of these systems and their similar structures will be studied. Owing to the management of social systems and the course of evolution of biotic systems may be regarded as control processes, the researches will be within the scope of control problems. Moreover, since it is difficult to model for biotic and social systems, it will start with the control problems of complex systems, possessing similar structures, in engineering. The obtained results show that for either linear or nonlinear systems and for a lot of control problems similar structures lead to a series of simplifications. In general, the original system may be decomposed into reduced amount of subsystems with lower dimensions and simpler structures. By virtue of such subsystems, the control problems of original system can be solved more simply. At last, it turns round to observe the biotic and social systems and some analyses are given.
摘要The complexity of linear, fixed-point arithmetic digital controllers is investigated from a Kolmogorov-Chaitin perspective. Based on the idea of Kolmogorov-Chaitin complexity, practical measures of complexity are developed for statespace realizations, parallel and cascade realizations, and for a newly proposed generalized implicit state-space realization. The complexity of solutions to a restricted complexity controller benchmark problem is investigated using this measure. The results show that from a Kolmogorov-Chaitin viewpoint, higher-order controllers with a shorter word-length may have lower complexity and better performance, than lower-order controllers with longer word-length.
基金Supported by the National High Technology Research and Development Program of China (2008AA01A313 ), the National Natural Science Foundation of China (60772069), and a Grant from the Centre for Signal Processing of the Hang Kong Polytechnic University (1-BB9c).
摘要In this paper, the complexity of intra coding is first analyzed so as to achieve a weight of complexity measurement for each intra mode. Then, a new complexity scalable control algorithm for intra coding in H. 264 is proposed, based on the rearrangement of the order of candidate modes and an efficient complexity allocation and control (CAAC) scheme at the macroblock (MB) level. The candidate modes of each MB are rearranged according to the local-edge information. Experimental results show that our proposed algorithm can make an appropriate cut-off point of the candidate modes sequence adaptively according to the current energy condition of a mobile device, so as to adjust the complexity at any level while maximizing the video quality, which can prolong the operational lifetime of the battery with minimum degradation in video quality.
摘要With the Rio Olympics just a few months past,we remember the excitement,the incredible performances,and the controversies.As happens so often,the Olympic Games focus attention not only on athletic achievements but also on how athletes may reach ever-increasing levels of performance.Doping,medical
基金supported by the National Key Research and Development Program of China under the grant of 2022YFB3403100。
摘要The dual three-phase PMSM(DTP-PMSM)drives have received wide attention at high-power high-efficiency applications due to their merits of high output current ability and copper-loss-free field excitation.Meanwhile,the DTPPMSM drive provides higher fault-tolerant capability for highreliability applications,e.g.,pumps and actuators in aircraft.For high-power drives with limited switching frequencies and highspeed drives with large fundamental frequencies,the ratio of switching frequency to fundamental frequency,i.e.,the carrier ratio,is usually below 15,which would significantly degrade the control performance.The purpose of this paper is to review the recent work on the modulation and control schemes for improving the operation performance of DTP-PMSM drives with low carrier ratios.Specifically,three categories of methods,i.e.,the space vector modulation based control,the model predictive control(MPC),and the optimized pulse pattern(OPP)based control are reviewed with principles and performance.In addition,brief discussions regarding the comparison and future trends are presented for low-carrier-ratio(LCR)modulation and control schemes of DTP-PMSM drives.
基金the National Natural Science Foundation of China (No.60774088, 60504017)the Specialized Research Fund for theDoctoral Program of Higher Education of China (No.20050055013)the Program for New Century Excellent Talents of China (NCET)
摘要The stabilization properties of various typical complex dynamical networks composed of chaotic nodes are theoretically investigated and numerically simulated in detail. Some local stability properties of such pinned networks are derived and the valid stability regions are estimated based on eigenvalue analysis. Numerical simulations of such networks are given to explain why significantly less local controllers are needed by the specifically pinning scheme, which pins the most highly connected nodes in scale-free networks, than that required by the randomly pinning scheme. Also, it is explained why there is no significant difference between the two schemes for controlling random-graph networks and small-world networks.
摘要The Brazilian electric sector reform established that the remuneration of distribution utilities must be through the management of their systems. This fact increased the necessity of control and management of load flows through the connection points between the distribution systems and the basic grid as a function of the contracted amounts. The objective of this control is to avoid that these flows exceed some thresholds along the contracted values, avoiding monetary penalties to the utility or unnecessary amounts of contracted flows that overrates the costumers. This question highlights the necessity of forecast the flows in these connection points in sufficient time to permit the operator to take decisions to avoid flows beyond the contracted ones. In this context, this work presents the development of a neural network based load flow forecaster, being tested two time-series neural models: support vector machines and Bayesian inference applied to multilayered perceptron. The models are applied to real data from a Brazilian distribution utility.
摘要In this paper, a real-time computation method for the control problems in differential-algebraic systems is presented. The errors of the method are estimated, and the relation between the sampling stepsize and the controlled errors is analyzed. The stability analysis is done for a model problem, and the stability region is ploted which gives the range of the sampling stepsizes with which the stability of control process is guaranteed.
摘要A complex autonomous inventory coupled system is considered. It can take, for example, the form of a network of chemical or biochemical reactors, where the inventory interactions perform the recycling of by-products between the subsystems. Because of the flexible subsystems interactions, each of them can be operated with their own periods utilizing advantageously their dynamic properties. A multifrequency second-order test generalizing the p-test for single systems is described. It can be used to decide which kind of the operation (the static one, the periodic one or the multiperiodic one) will intensify the productivity of a complex system. An illustrative example of the multiperiodic optimization of a complex chemical production system is presented.
摘要Stability criteria for the complex-valued impulsive system are applied widely in many fields, such as quantum systems, which have been studied in recent decades. In this paper, I investigate the Lyapunov control of finite dimensional complex-valued systems with impulsive control fields, where the studied complex-valued systems are governed by the Schrödinger equation and can be used in quantum systems. By one Lyapunov function based on state error and the invariant principle of impulsive systems, I study the convergence of complex-valued systems with impulsive control fields and propose new results for the mentioned complex-valued systems in the form of sufficient conditions. A numerical simulation to validate the proposed control method is provided.
基金supported by Key Program of National Natural Science Foundation of China (No. 61533011)National Natural Science Foundation of China (Nos. 61273088 and 61603203)
摘要The aim of this paper is to study complex modified projective synchronization(CMPS) between fractional-order chaotic nonlinear systems with incommensurate orders. Based on the stability theory of incommensurate fractional-order systems and active control method, control laws are derived to achieve CMPS in three situations including fractional-order complex Lorenz system driving fractional-order complex Chen system, fractional-order real Rssler system driving fractional-order complex Chen system, and fractionalorder complex Lorenz system driving fractional-order real Lü system. Numerical simulations confirm the validity and feasibility of the analytical method.
摘要针对系统理论过程分析(STPA,systems-theoretic process analysis)在民机机载系统安全性分析中存在的局限性,首先,本文基于复杂网络理论将控制结构模型转化为致因传播网络,以出入度等参数反映信息交互和致因传播情况,实现系统故障的关键部件定位,从而进行针对性防控。其次,针对STPA方法,从安全性需求捕获、安全性验证、关键致因识别3个方面提出改进,完善系统安全性评估确认与验证过程。最后,以襟翼控制系统为应用对象,验证该方法的可行性和有效性,可为复杂机载系统提供一种系统的安全性分析思路。
基金co-supported by the State Key Program of National Natural Science Foundation of China (No. 91538204)the National Science Fund for Distinguished Young Scholars (No. 61425014)the National Key Technologies R&D Program of China (No. 2015BAG15B01)
摘要Air traffic complexity is an objective metric for evaluating the operational condition of the airspace. It has several applications, such as airspace design and traffic flow management.Therefore, identifying a reliable method to accurately measure traffic complexity is important. Considering that many factors correlate with traffic complexity in complicated nonlinear ways,researchers have proposed several complexity evaluation methods based on machine learning models which were trained with large samples. However, the high cost of sample collection usually results in limited training set. In this paper, an ensemble learning model is proposed for measuring air traffic complexity within a sector based on small samples. To exploit the classification information within each factor, multiple diverse factor subsets(FSSs) are generated under guidance from factor noise and independence analysis. Then, a base complexity evaluator is built corresponding to each FSS. The final complexity evaluation result is obtained by integrating all results from the base evaluators. Experimental studies using real-world air traffic operation data demonstrate the advantages of our model for small-sample-based traffic complexity evaluation over other stateof-the-art methods.