To solve the different time delays that exist in the control device installed on spatial structures, in this study, discrete analysis using a 2N precise algorithm was selected to solve the multi-time-delay issue for l...To solve the different time delays that exist in the control device installed on spatial structures, in this study, discrete analysis using a 2N precise algorithm was selected to solve the multi-time-delay issue for long-span structures based on the market-based control （MBC） method. The concept of interval mixed energy was introduced from computational structural mechanics and optimal control research areas, and it translates the design of the MBC multi-time-delay controller into a solution for the segment matrix. This approach transforms the serial algorithm in time to parallel computing in space, greatly improving the solving efficiency and numerical stability. The designed controller is able to consider the issue of time delay with a linear controlling force combination and is especially effective for large time-delay conditions. A numerical example of a long-span structure was selected to demonstrate the effectiveness of the presented controller, and the time delay was found to have a significant impact on the results.展开更多
This paper concerns the observer-based adaptive control problem of uncertain time-delay switched systems with stuck actuator faults. Under the case where the original controller cannot stabilize the faulty system, mul...This paper concerns the observer-based adaptive control problem of uncertain time-delay switched systems with stuck actuator faults. Under the case where the original controller cannot stabilize the faulty system, multiple adaptive controllers are designed and a suitable switching logic is incorporated to ensure the closed-loop system stability and state tracking. New delay-independent sufficient conditions for asymptotic stability are obtained in terms of linear matrix inequalities based on piecewise Lyapunov stability theory. On the other hand, adaptive laws for on-line updating of some of the controller parameters are also designed to compensate the effect of stuck failures. Finally, simulation results for reference [1] model show that the design is feasible and efficient.展开更多
A parallel neural network-based controller （PNNC） is presented for the motion control of underwater vehicles in this paper. It consists of a real-time part, a self-learning part and a desired-state programmer, and i...A parallel neural network-based controller （PNNC） is presented for the motion control of underwater vehicles in this paper. It consists of a real-time part, a self-learning part and a desired-state programmer, and it is different from normal adaptive neural network controller in structure. Owing to the introduction of the self-learning part, on-line learning can be performed without sample data in several sample periods, resulting in high learning speed of the controller and good control performance. The desired-state programmer is utilized to obtain better learning samples of the neural network to keep the stability of the controller. The developed controller is applied to the 4-degree of freedom control of the AUV “IUV- IV” and is successful on the simulation platform. The control performance is also compared with that of neural network controller with different structures such as normal adaptive neural network and different learning methods. Current effects and surge velocity control are also included to demonstrate the controller＇ s performance. It is shown that the PNNC has a great possibility to solve the problems in the control system design of underwater vehicles.展开更多
In this paper,a novel control structure called feedback scheduling of model-based networked control systems is proposed to cope with a flexible network load and resource constraints.The state update time is adjusted a...In this paper,a novel control structure called feedback scheduling of model-based networked control systems is proposed to cope with a flexible network load and resource constraints.The state update time is adjusted according to the real-time network congestion situation.State observer is used under the situation where the state of the controlled plant could not be acquired.The stability criterion of the proposed structure is proved with time-varying state update time.On the basis of the stability of the novel system structure,the compromise between the control performance and the network utilization is realized by using feedback scheduler. Examples are provided to show the advantage of the proposed control structure.展开更多
To improve the consistency of the adhesive amount dispensed by the time-pressure dispenser for semiconductor manufacturing, a non-Newtonian fluid flow rate model is developed to represent and estimate the adhesive amo...To improve the consistency of the adhesive amount dispensed by the time-pressure dispenser for semiconductor manufacturing, a non-Newtonian fluid flow rate model is developed to represent and estimate the adhesive amount dispensed in each cycle. Taking account of gas compressibility, an intelligent model-based control strategy is proposed to compensate the deviation of adhesive amount dispensed from the desired one. Both simulations and experiments show that the dispensing consistency is greatly improved by using the model-based control strategy developed in this paper.展开更多
This article concerns a coupled LMIs approach to delay-dependent observer-based output feedback stabilizing controller design for linear continuous-time systems with multiple state delays. The advantage of our propose...This article concerns a coupled LMIs approach to delay-dependent observer-based output feedback stabilizing controller design for linear continuous-time systems with multiple state delays. The advantage of our proposed delay-dependent coupled LMIs criterion lies in that: ( 1 ) it can optimize one of multiple time delays with others selected properly, and at the same time, the feedback-gain and observer-gain can be obtained, respectively. (2) it is less conservative than the existing delay-independent ones in the literature. Algorithm to solve the coupled LMIs is also given. Numerical examples illustrate the effectiveness of our method. Keywords Delay-dependent criterion - Time-delay system - Multiple time-delay - Observer-based controller - Linear matrixinequality (LMI)展开更多
Time-triggered （TT） embedded software pattern is well accepted in aerospace industry for its high reliability. Fi-nite-state-machine （FSM） design method is widely used for its high efficiency and predictable behav...Time-triggered （TT） embedded software pattern is well accepted in aerospace industry for its high reliability. Fi-nite-state-machine （FSM） design method is widely used for its high efficiency and predictable behavior. In this paper, the time-triggered and state-machine combination software architecture is implemented for a 25 kg thrust micro turbine engine （MTE） used for unmanned aerial vehicle （UAV） system; also model-based-design development workflow for airworthiness software directive DO-178B is utilized. Experimental results show that time-triggered state-machine software architecture and development method could shorten the system development time, reduce the system test cost and make the turbine engine easily comply with the airworthiness rules.展开更多
Owing to the dynamics coupling between a free-floating base and a manipulator, the non-stationary base of a space robot will face the issue of base disturbance due to a manipulator＇s motion. The reaction torque acted...Owing to the dynamics coupling between a free-floating base and a manipulator, the non-stationary base of a space robot will face the issue of base disturbance due to a manipulator＇s motion. The reaction torque acted on the satellite base＇s centroid is an important index to measure the satellite base＇s disturbance. In this paper, a comprehensive analysis of the reaction torque is made, and a novel way to derive the analytical form of the reaction torque is proposed. In addition,the reaction torque null-space is derived, in which the manipulator＇s joint motion is dynamically decoupled from the motion of the satellite base, and its novel expression demonstrates the equivalence between the reaction torque null-space and the reaction null-space. Furthermore, the reaction torque acted as an optimization index can be utilized to achieve satellite base disturbance minimization in the generalized Jacobian-based end-effector Cartesian path tracking task. Besides, supposing that the redundant degrees of freedom are abundant to achieve reaction torque-based active control, the reaction torque can be used to realize satellite base attitude control, that is, base attitude adjustment or maintenance. Moreover, because reaction torque-based control is a second-order control scheme, joint torque minimization can be regarded as the optimization task in reaction torque-based active or in-active control. A real-time simulation system of a 7-DOF space robot under Linux/RTAI is developed to verify and test the feasibility and reliability of the proposed ideas. Our extensive empirical results demonstrate that the corresponding analysis about the reaction torque is correct and the proposed methods are feasible.展开更多
在受端交流侧发生故障时,现有依赖耗能装置的基于模块化多电平换流器的多端柔性直流(modular multilevel converter based multi-terminal direct current,MMC-MTDC)输电系统,其盈余功率处理方案存在经济性差和能量浪费等问题。为充分发...在受端交流侧发生故障时,现有依赖耗能装置的基于模块化多电平换流器的多端柔性直流(modular multilevel converter based multi-terminal direct current,MMC-MTDC)输电系统,其盈余功率处理方案存在经济性差和能量浪费等问题。为充分发挥MMC-MTDC系统自有盈余功率消纳能力,减少对耗能装置的依赖,文中提出一种基于主从能量控制的多站极间交互消纳策略。首先,建立相应的MMC-MTDC控制模型,并对其通过能量控制实现盈余功率消纳的可行性进行分析。随后,引入MMC三维度模型,实现换流站各极能量解耦控制,并通过构建的MMC-MTDC系统简化模型,对各类型换流站开展主动能量控制设计。在此基础上,类比主从控制思想,构建适用于不同受端站极交流故障及两类盈余功率情况的主从能量时序控制逻辑,以实现各站极之间的能量裕度协调利用。最后,在PSCAD/EMTDC平台搭建MMC-MTDC系统仿真模型进行实验验证。仿真结果表明,所提控制策略能够在不依赖耗能装置的前提下,有效协调多站极之间的能量控制,适应多种盈余功率故障情况,成功实现故障穿越。展开更多
This paper presents a novel method to solve old problem of water level control system of pressurized water reactor (PWR) steam generator (SG) of nuclear power plant (NPP) .The level control system of SG plays an impo...This paper presents a novel method to solve old problem of water level control system of pressurized water reactor (PWR) steam generator (SG) of nuclear power plant (NPP) .The level control system of SG plays an important role which effects the reliablity,safty,cost of SG and its mathematical models have been solved.A model of the conventional controller is presented and the existing problems are discussed. A novel rule based realtime control technique is designed with a computerized water level control (CWLC) system for SG of PWR NPP.The performance of this is evaluated for full power reactor operating conditions by applying different transient conditions of SG′s data of Qinshan Nuclear Power Plant (QNPP).展开更多
Particle accelerators are devices used for research in scientific problems such as high energy and nuclear physics.In a particle accelerator, the shape of particle beam envelope is changed dynamically along the forwar...Particle accelerators are devices used for research in scientific problems such as high energy and nuclear physics.In a particle accelerator, the shape of particle beam envelope is changed dynamically along the forward direction. Thus, this reference direction can be considered as an auxiliary "time" beam axis. In this paper, the optimal beam matching control problem for a low energy transport system in a charged particle accelerator is considered. The beam matching procedure is formulated as a finite "time" dynamic optimization problem, in which the Kapchinsky-Vladimirsky(K-V) coupled envelope equations model beam dynamics. The aim is to drive any arbitrary initial beam state to a prescribed target state, as well as to track reference trajectory as closely as possible, through the control of the lens focusing strengths in the beam matching channel. We first apply the control parameterization method to optimize lens focusing strengths, and then combine this with the time-scaling transformation technique to further optimize the drift and lens length in the beam matching channel. The exact gradients of the cost function with respect to the decision parameters are computed explicitly through the state sensitivity-based analysis method. Finally, numerical simulations are illustrated to verify the effectiveness of the proposed approach.展开更多
This paper presents the reaction torque based satellite base reactionless control or base disturbance minimization of a redundant free-floating space robot. This subject is of vital importance in the study of the free...This paper presents the reaction torque based satellite base reactionless control or base disturbance minimization of a redundant free-floating space robot. This subject is of vital importance in the study of the free-floating space robot because the base disturbance minimization will result in less energy consumption and prolonged control application. The analytical formulation of the reaction torque is derived in this article, and the reaction torque control can achieve reactionless control and satellite base disturbance minimization. Furthermore, we derive the reaction torque based control of the space robot for base disturbance minimization from both the non-strict task priority and strict task priority control strategy. The dynamics singularity in the proposed algorithm is avoided in this paper. Besides, a real time simulation system of the space robot under Linux/real time application interface（RTAI） is developed to verify and test the feasibility and reliability of the method. The experimental results demonstrate the feasibility of online reaction torque control of the redundant free-floating space robot.展开更多
In this paper we present a new projective synchronization scheme, where two chaotic （hyperchaotic） discrete-time systems synchronize for any arbitrary scaling matrix. Specifically, each drive system state synchroniz...In this paper we present a new projective synchronization scheme, where two chaotic （hyperchaotic） discrete-time systems synchronize for any arbitrary scaling matrix. Specifically, each drive system state synchronizes with a linear combination of response system states. The proposed observer-based approach presents some useful features： i） it enables exact synchronization to be achieved in finite time （i.e., dead-beat synchronization）; ii） it exploits a scalar synchronizing signal; iii） it can be applied to a wide class of discrete-time chaotic （hyperchaotic） systems; iv） it includes, as a particular case, most of the synchronization types defined so far. An example is reported, which shows in detail that exact synchronization is effectively achieved in finite time, using a scalar synchronizing signal only, for any arbitrary scaling matrix.展开更多
基金provided by the Science Fund for Creative Research Groups of the National Natural Science Foundation of China under Grant Nos.51261120375 and 51421064
文摘To solve the different time delays that exist in the control device installed on spatial structures, in this study, discrete analysis using a 2N precise algorithm was selected to solve the multi-time-delay issue for long-span structures based on the market-based control （MBC） method. The concept of interval mixed energy was introduced from computational structural mechanics and optimal control research areas, and it translates the design of the MBC multi-time-delay controller into a solution for the segment matrix. This approach transforms the serial algorithm in time to parallel computing in space, greatly improving the solving efficiency and numerical stability. The designed controller is able to consider the issue of time delay with a linear controlling force combination and is especially effective for large time-delay conditions. A numerical example of a long-span structure was selected to demonstrate the effectiveness of the presented controller, and the time delay was found to have a significant impact on the results.
基金supported by the National Basic Research Program of China (No.2007CB714006)
文摘This paper concerns the observer-based adaptive control problem of uncertain time-delay switched systems with stuck actuator faults. Under the case where the original controller cannot stabilize the faulty system, multiple adaptive controllers are designed and a suitable switching logic is incorporated to ensure the closed-loop system stability and state tracking. New delay-independent sufficient conditions for asymptotic stability are obtained in terms of linear matrix inequalities based on piecewise Lyapunov stability theory. On the other hand, adaptive laws for on-line updating of some of the controller parameters are also designed to compensate the effect of stuck failures. Finally, simulation results for reference [1] model show that the design is feasible and efficient.
文摘A parallel neural network-based controller （PNNC） is presented for the motion control of underwater vehicles in this paper. It consists of a real-time part, a self-learning part and a desired-state programmer, and it is different from normal adaptive neural network controller in structure. Owing to the introduction of the self-learning part, on-line learning can be performed without sample data in several sample periods, resulting in high learning speed of the controller and good control performance. The desired-state programmer is utilized to obtain better learning samples of the neural network to keep the stability of the controller. The developed controller is applied to the 4-degree of freedom control of the AUV “IUV- IV” and is successful on the simulation platform. The control performance is also compared with that of neural network controller with different structures such as normal adaptive neural network and different learning methods. Current effects and surge velocity control are also included to demonstrate the controller＇ s performance. It is shown that the PNNC has a great possibility to solve the problems in the control system design of underwater vehicles.
文摘In this paper,a novel control structure called feedback scheduling of model-based networked control systems is proposed to cope with a flexible network load and resource constraints.The state update time is adjusted according to the real-time network congestion situation.State observer is used under the situation where the state of the controlled plant could not be acquired.The stability criterion of the proposed structure is proved with time-varying state update time.On the basis of the stability of the novel system structure,the compromise between the control performance and the network utilization is realized by using feedback scheduler. Examples are provided to show the advantage of the proposed control structure.
基金This work was supported by National Natural Science Foundation of China (No.50390063,50390064)the National Basic Research Program of China (973 Program) (No.2003CB716207).
文摘To improve the consistency of the adhesive amount dispensed by the time-pressure dispenser for semiconductor manufacturing, a non-Newtonian fluid flow rate model is developed to represent and estimate the adhesive amount dispensed in each cycle. Taking account of gas compressibility, an intelligent model-based control strategy is proposed to compensate the deviation of adhesive amount dispensed from the desired one. Both simulations and experiments show that the dispensing consistency is greatly improved by using the model-based control strategy developed in this paper.
文摘This article concerns a coupled LMIs approach to delay-dependent observer-based output feedback stabilizing controller design for linear continuous-time systems with multiple state delays. The advantage of our proposed delay-dependent coupled LMIs criterion lies in that: ( 1 ) it can optimize one of multiple time delays with others selected properly, and at the same time, the feedback-gain and observer-gain can be obtained, respectively. (2) it is less conservative than the existing delay-independent ones in the literature. Algorithm to solve the coupled LMIs is also given. Numerical examples illustrate the effectiveness of our method. Keywords Delay-dependent criterion - Time-delay system - Multiple time-delay - Observer-based controller - Linear matrixinequality (LMI)
文摘Time-triggered （TT） embedded software pattern is well accepted in aerospace industry for its high reliability. Fi-nite-state-machine （FSM） design method is widely used for its high efficiency and predictable behavior. In this paper, the time-triggered and state-machine combination software architecture is implemented for a 25 kg thrust micro turbine engine （MTE） used for unmanned aerial vehicle （UAV） system; also model-based-design development workflow for airworthiness software directive DO-178B is utilized. Experimental results show that time-triggered state-machine software architecture and development method could shorten the system development time, reduce the system test cost and make the turbine engine easily comply with the airworthiness rules.
基金supported in part by the National Program on Key Basic Research Project 973 Program under Grant 2013CB733103the Program for New Century Excellent Talents in University under Grand NCET-10-0058
文摘Owing to the dynamics coupling between a free-floating base and a manipulator, the non-stationary base of a space robot will face the issue of base disturbance due to a manipulator＇s motion. The reaction torque acted on the satellite base＇s centroid is an important index to measure the satellite base＇s disturbance. In this paper, a comprehensive analysis of the reaction torque is made, and a novel way to derive the analytical form of the reaction torque is proposed. In addition,the reaction torque null-space is derived, in which the manipulator＇s joint motion is dynamically decoupled from the motion of the satellite base, and its novel expression demonstrates the equivalence between the reaction torque null-space and the reaction null-space. Furthermore, the reaction torque acted as an optimization index can be utilized to achieve satellite base disturbance minimization in the generalized Jacobian-based end-effector Cartesian path tracking task. Besides, supposing that the redundant degrees of freedom are abundant to achieve reaction torque-based active control, the reaction torque can be used to realize satellite base attitude control, that is, base attitude adjustment or maintenance. Moreover, because reaction torque-based control is a second-order control scheme, joint torque minimization can be regarded as the optimization task in reaction torque-based active or in-active control. A real-time simulation system of a 7-DOF space robot under Linux/RTAI is developed to verify and test the feasibility and reliability of the proposed ideas. Our extensive empirical results demonstrate that the corresponding analysis about the reaction torque is correct and the proposed methods are feasible.
文摘在受端交流侧发生故障时,现有依赖耗能装置的基于模块化多电平换流器的多端柔性直流(modular multilevel converter based multi-terminal direct current,MMC-MTDC)输电系统,其盈余功率处理方案存在经济性差和能量浪费等问题。为充分发挥MMC-MTDC系统自有盈余功率消纳能力,减少对耗能装置的依赖,文中提出一种基于主从能量控制的多站极间交互消纳策略。首先,建立相应的MMC-MTDC控制模型,并对其通过能量控制实现盈余功率消纳的可行性进行分析。随后,引入MMC三维度模型,实现换流站各极能量解耦控制,并通过构建的MMC-MTDC系统简化模型,对各类型换流站开展主动能量控制设计。在此基础上,类比主从控制思想,构建适用于不同受端站极交流故障及两类盈余功率情况的主从能量时序控制逻辑,以实现各站极之间的能量裕度协调利用。最后,在PSCAD/EMTDC平台搭建MMC-MTDC系统仿真模型进行实验验证。仿真结果表明,所提控制策略能够在不依赖耗能装置的前提下,有效协调多站极之间的能量控制,适应多种盈余功率故障情况,成功实现故障穿越。
文摘This paper presents a novel method to solve old problem of water level control system of pressurized water reactor (PWR) steam generator (SG) of nuclear power plant (NPP) .The level control system of SG plays an important role which effects the reliablity,safty,cost of SG and its mathematical models have been solved.A model of the conventional controller is presented and the existing problems are discussed. A novel rule based realtime control technique is designed with a computerized water level control (CWLC) system for SG of PWR NPP.The performance of this is evaluated for full power reactor operating conditions by applying different transient conditions of SG′s data of Qinshan Nuclear Power Plant (QNPP).
基金supported by the National Natural Science Foundation of China(61703114,61673126,61703217,U1701261)the Science and Technology Plan Project of Guangdong(2014B090907010,2015B010131014)
文摘Particle accelerators are devices used for research in scientific problems such as high energy and nuclear physics.In a particle accelerator, the shape of particle beam envelope is changed dynamically along the forward direction. Thus, this reference direction can be considered as an auxiliary "time" beam axis. In this paper, the optimal beam matching control problem for a low energy transport system in a charged particle accelerator is considered. The beam matching procedure is formulated as a finite "time" dynamic optimization problem, in which the Kapchinsky-Vladimirsky(K-V) coupled envelope equations model beam dynamics. The aim is to drive any arbitrary initial beam state to a prescribed target state, as well as to track reference trajectory as closely as possible, through the control of the lens focusing strengths in the beam matching channel. We first apply the control parameterization method to optimize lens focusing strengths, and then combine this with the time-scaling transformation technique to further optimize the drift and lens length in the beam matching channel. The exact gradients of the cost function with respect to the decision parameters are computed explicitly through the state sensitivity-based analysis method. Finally, numerical simulations are illustrated to verify the effectiveness of the proposed approach.
基金supported by National Basic Research Program of China(973 Program)(No.2013CB733103)Program for New Century Excellent Talents in University(No.NCET-10-0058)
文摘This paper presents the reaction torque based satellite base reactionless control or base disturbance minimization of a redundant free-floating space robot. This subject is of vital importance in the study of the free-floating space robot because the base disturbance minimization will result in less energy consumption and prolonged control application. The analytical formulation of the reaction torque is derived in this article, and the reaction torque control can achieve reactionless control and satellite base disturbance minimization. Furthermore, we derive the reaction torque based control of the space robot for base disturbance minimization from both the non-strict task priority and strict task priority control strategy. The dynamics singularity in the proposed algorithm is avoided in this paper. Besides, a real time simulation system of the space robot under Linux/real time application interface（RTAI） is developed to verify and test the feasibility and reliability of the method. The experimental results demonstrate the feasibility of online reaction torque control of the redundant free-floating space robot.
文摘In this paper we present a new projective synchronization scheme, where two chaotic （hyperchaotic） discrete-time systems synchronize for any arbitrary scaling matrix. Specifically, each drive system state synchronizes with a linear combination of response system states. The proposed observer-based approach presents some useful features： i） it enables exact synchronization to be achieved in finite time （i.e., dead-beat synchronization）; ii） it exploits a scalar synchronizing signal; iii） it can be applied to a wide class of discrete-time chaotic （hyperchaotic） systems; iv） it includes, as a particular case, most of the synchronization types defined so far. An example is reported, which shows in detail that exact synchronization is effectively achieved in finite time, using a scalar synchronizing signal only, for any arbitrary scaling matrix.
