The ultrasonic motor is a sort of new type of micromotor with special structure. By use of piezoelectric converse effect of ceramics, the electrical energy is transformed into mechanical energy. Its operating principl...The ultrasonic motor is a sort of new type of micromotor with special structure. By use of piezoelectric converse effect of ceramics, the electrical energy is transformed into mechanical energy. Its operating principle is quite different from that of the traditional motors. In this paper the equivalent circuits of the ring stator and even the whole motor are proposed after studying the equivalent circuit of piezoelectric vibrator. Then the paper makes detailed analyses of each part of the control system, which has been simplified by the equivalent circuit. The theory in this paper has been proved through experiments.展开更多
Cell control system(CCS) plays an important role in the hierarchical control structure of computer integrated manufacturing system(CIMS). It links up workshop controller and CAD/CAPP/CAM down to production facilities,...Cell control system(CCS) plays an important role in the hierarchical control structure of computer integrated manufacturing system(CIMS). It links up workshop controller and CAD/CAPP/CAM down to production facilities, and directly influences flexibility and efficiency of production. The hierarchical control structure and the key technical problems of the CCS are mainly described. The CCS controls the job schedule, the resource allocation and the operation of facilities in the manufacturing procedure according to the production plan and target coming from the workshop controller. The key technologies are discussed in this paper as follows: the application of client/server system structure in the production control and management; production planning and scheduling; the handling of exceptional incidents in production and the DNC interface control as well.展开更多
Aim To present an adaptive missile control system adaped to the external disturbance and the mobility of target movement. Methods Model reference adaptive control (MRAC) was applied and modified in the light of the ...Aim To present an adaptive missile control system adaped to the external disturbance and the mobility of target movement. Methods Model reference adaptive control (MRAC) was applied and modified in the light of the traits of the anti tank missile. Results Simulation results demonstrated this control system satisfied the requirement of anti tank missile of dive overhead attack. Conclusion It is successful to use MRAC in missile control system design, the quality is better than that designed by classical control theory.展开更多
A μ analysis and μ synthesis method for nonlinear robust control systems was presented. The nonlinear robust contrl problem using μ method was described. By means of the nonlinear state feedback and state coordin...A μ analysis and μ synthesis method for nonlinear robust control systems was presented. The nonlinear robust contrl problem using μ method was described. By means of the nonlinear state feedback and state coordinates transformation, many uncertain nonlinear systems can be transformed as a linear fractional transformation (LFT) on the generalized plant and the uncertainty. Based on the LFT, a linear robust controller can be obtained by the DK iteration and then a corresponding nonlinear robust control law is constructed. An example was given in the paper.展开更多
A dynamic model of magnetic levitation control system with nonlinear magnetic force and feedback control is presented. Because of nonlinear magnetic force, the complex dynamic behavior will be shown in the system (cod...A dynamic model of magnetic levitation control system with nonlinear magnetic force and feedback control is presented. Because of nonlinear magnetic force, the complex dynamic behavior will be shown in the system (codimension two bifurcation, Hopf bifurcation, heteroclinic bifurcation). By theoretical analysis, it is shown that the design of parameters has a close relation with the systems stability; the range of selected parameters is achieved when the controller system is stable, based on the condition of bifurcation parameters, bifurcation curve, bifurcation set and phase portraits. From the simulating of magnetic flywheel system, the complex dynamic behavior is shown, and the result is in correspondence with the theoretics. It is of great theoretic importance to improve design and stable control for the nonlinear magnetic levitation control system.展开更多
The problem of robust controller design with covariance constraint for uncertain sampled data feedback control systems was considered in this paper. The goal of this problem is to design controllers such that the clo...The problem of robust controller design with covariance constraint for uncertain sampled data feedback control systems was considered in this paper. The goal of this problem is to design controllers such that the closed loop system meets the prespecified covariance constraint. This problem can be reduced to a controller design problem for an equivalent uncertain discrete time system. Sufficient conditions were given for the existence of the desired controllers. The analytical expression of the set of desired controllers was also presented. An illustrative example was given to show the applicability of the proposed design procedure.展开更多
A type of nonlinear dynamic inversion control with adaptive compensation is proposed in order to overcome its over sensitivity to parameter uncertainty and disturbance for flight control system using nonlinear dynam...A type of nonlinear dynamic inversion control with adaptive compensation is proposed in order to overcome its over sensitivity to parameter uncertainty and disturbance for flight control system using nonlinear dynamic inversion. This control strategy is different from the general strategy of a nonlinear adaptive control by taking into consideration both parameter uncertainty and external disturbance, the two major uncertain forms in flight control. Finally, an analysis of the stabilily of this control structure is given.展开更多
In this paper, the problem of absolute stability of continuous time with parametric nonlinear system uncertainty of a linear part and sector uncertainty of its nonlinear part is considered, the and sufficient conditi...In this paper, the problem of absolute stability of continuous time with parametric nonlinear system uncertainty of a linear part and sector uncertainty of its nonlinear part is considered, the and sufficient conditions for absolute stability of direct and indirect control systems are presented. The corresponding results for robust absolute stability are improved.展开更多
Based on mechanics to design hollow plastic parison shape,this paper adopted computer and programmable logic controllers(PLCs) to build a three level system,finish the CAD of parison,and control the blow molding seque...Based on mechanics to design hollow plastic parison shape,this paper adopted computer and programmable logic controllers(PLCs) to build a three level system,finish the CAD of parison,and control the blow molding sequentially.Parison thickness was controlled by an electro hydraulic proportional control system,which controls the gap between the parison and the nozzle during the extrusion process by regulating the position of the core bar.Both constant pressure and speed control systems were adopted to control the process of plastic storing and extrusion,and PLC,such as C200H and CQM1,fuzzy modules were adopted.The results show that the part quality of blow molding can be improved greatly.展开更多
Many process control systems are a kind of hybrid systems. In order to develop a satisfied control strategy, i. e., to make the whole system satisfy some processing requirements, the knowledge of plant is indispensabl...Many process control systems are a kind of hybrid systems. In order to develop a satisfied control strategy, i. e., to make the whole system satisfy some processing requirements, the knowledge of plant is indispensable. This paper proposes a formal model for the general plant for a kind of process control systems. Based on the model, requirements for the system can be specified from goals, and the controller can be designed according to plant based formal approach . An industrial process control system is used to illustrate our models and methods. Duration Calculus, a real time interval logic, is utilized to specify some characters of the model and development of control program for the exemplified system.展开更多
Absolute stability problem has theoretical and engineering importance for control engineering and control theory. In this paper, based on the dimension reducing method, sufficient conditions for the absolute stability...Absolute stability problem has theoretical and engineering importance for control engineering and control theory. In this paper, based on the dimension reducing method, sufficient conditions for the absolute stability of several classes of Lurie control systems are given.展开更多
Based on the CMAC (cerebellar model articulation controller) model and Lyapunov stability law,a controller design method using cost function was proposed,the parameter selecting method of the controller was obtained b...Based on the CMAC (cerebellar model articulation controller) model and Lyapunov stability law,a controller design method using cost function was proposed,the parameter selecting method of the controller was obtained by analyzing the convergence of control algorithms and the stability of the control system.The strategy is applicable to the process where output can be measured and a CMAC model has been obtained.A simulation example is given to demonstrate the correctness and practicality of the proposed strategy.展开更多
This paper presents the scheme of the Fuzzy Homogeneous Combustion Control System (FHCCS) and its practical use on site. The operating results of the system show that FHCCS can not only operate normally, but also gua...This paper presents the scheme of the Fuzzy Homogeneous Combustion Control System (FHCCS) and its practical use on site. The operating results of the system show that FHCCS can not only operate normally, but also guarantee the homogeneous combustion in each level of burner and at optimal air coal ratio of each burner. Some engineering problems about FHCCS implementation are discussed in this paper.展开更多
After giving a short review of the methods used for detecting and monitoring in general systems, this paper describes the way of communication between computer and Computer Numerical Control (CNC) Machining Center (MC...After giving a short review of the methods used for detecting and monitoring in general systems, this paper describes the way of communication between computer and Computer Numerical Control (CNC) Machining Center (MC). Based on these, the paper addresses the means of performing in cycle measurement for manufacturing quality, provides an approach of improving the state of manufacturing process by achieving the real time change of control parameters according to the level of manufacturing process, and discusses the technique of implementing in process dimensional errors compensation corresponding to the in cycle measurement. The results of the experiments show that the frame design is successful and the operation is reliable. The system is taking shape nowadays.展开更多
Time delay existes widely in various real engineering systems and can result in unsatisfactory performance or even an instability of control systems. Therefore, to investigate the stability for time delay systems is o...Time delay existes widely in various real engineering systems and can result in unsatisfactory performance or even an instability of control systems. Therefore, to investigate the stability for time delay systems is of vitul importance in control theory and its applications. Many researchers have studied the stability criteria of systems with constant delay or bound varying time delay, but few of them studied large time delay or unbound time delay. Large time delay existes commonly in various engineering applications. In this paper, the absolute stability of Lurie type direct control systems and indirect control systems with several time delays are discussed. Based on Lyapunov theory, the new delay dependent absolute stability criteria are derived. In our theorem, time delays can be unbound functions, which shows that the results are less conservative than that of existed criteria.展开更多
文摘The ultrasonic motor is a sort of new type of micromotor with special structure. By use of piezoelectric converse effect of ceramics, the electrical energy is transformed into mechanical energy. Its operating principle is quite different from that of the traditional motors. In this paper the equivalent circuits of the ring stator and even the whole motor are proposed after studying the equivalent circuit of piezoelectric vibrator. Then the paper makes detailed analyses of each part of the control system, which has been simplified by the equivalent circuit. The theory in this paper has been proved through experiments.
文摘Cell control system(CCS) plays an important role in the hierarchical control structure of computer integrated manufacturing system(CIMS). It links up workshop controller and CAD/CAPP/CAM down to production facilities, and directly influences flexibility and efficiency of production. The hierarchical control structure and the key technical problems of the CCS are mainly described. The CCS controls the job schedule, the resource allocation and the operation of facilities in the manufacturing procedure according to the production plan and target coming from the workshop controller. The key technologies are discussed in this paper as follows: the application of client/server system structure in the production control and management; production planning and scheduling; the handling of exceptional incidents in production and the DNC interface control as well.
文摘Aim To present an adaptive missile control system adaped to the external disturbance and the mobility of target movement. Methods Model reference adaptive control (MRAC) was applied and modified in the light of the traits of the anti tank missile. Results Simulation results demonstrated this control system satisfied the requirement of anti tank missile of dive overhead attack. Conclusion It is successful to use MRAC in missile control system design, the quality is better than that designed by classical control theory.
文摘A μ analysis and μ synthesis method for nonlinear robust control systems was presented. The nonlinear robust contrl problem using μ method was described. By means of the nonlinear state feedback and state coordinates transformation, many uncertain nonlinear systems can be transformed as a linear fractional transformation (LFT) on the generalized plant and the uncertainty. Based on the LFT, a linear robust controller can be obtained by the DK iteration and then a corresponding nonlinear robust control law is constructed. An example was given in the paper.
文摘A dynamic model of magnetic levitation control system with nonlinear magnetic force and feedback control is presented. Because of nonlinear magnetic force, the complex dynamic behavior will be shown in the system (codimension two bifurcation, Hopf bifurcation, heteroclinic bifurcation). By theoretical analysis, it is shown that the design of parameters has a close relation with the systems stability; the range of selected parameters is achieved when the controller system is stable, based on the condition of bifurcation parameters, bifurcation curve, bifurcation set and phase portraits. From the simulating of magnetic flywheel system, the complex dynamic behavior is shown, and the result is in correspondence with the theoretics. It is of great theoretic importance to improve design and stable control for the nonlinear magnetic levitation control system.
基金Supported by National Natural Science Foundation of China 60404022, 60704009）, National Outstanding Youth Foundation 60525303）, and Natural Science Foundation of Hebei Province F2005000390, F2006000270）
文摘The problem of robust controller design with covariance constraint for uncertain sampled data feedback control systems was considered in this paper. The goal of this problem is to design controllers such that the closed loop system meets the prespecified covariance constraint. This problem can be reduced to a controller design problem for an equivalent uncertain discrete time system. Sufficient conditions were given for the existence of the desired controllers. The analytical expression of the set of desired controllers was also presented. An illustrative example was given to show the applicability of the proposed design procedure.
文摘A type of nonlinear dynamic inversion control with adaptive compensation is proposed in order to overcome its over sensitivity to parameter uncertainty and disturbance for flight control system using nonlinear dynamic inversion. This control strategy is different from the general strategy of a nonlinear adaptive control by taking into consideration both parameter uncertainty and external disturbance, the two major uncertain forms in flight control. Finally, an analysis of the stabilily of this control structure is given.
文摘In this paper, the problem of absolute stability of continuous time with parametric nonlinear system uncertainty of a linear part and sector uncertainty of its nonlinear part is considered, the and sufficient conditions for absolute stability of direct and indirect control systems are presented. The corresponding results for robust absolute stability are improved.
文摘Based on mechanics to design hollow plastic parison shape,this paper adopted computer and programmable logic controllers(PLCs) to build a three level system,finish the CAD of parison,and control the blow molding sequentially.Parison thickness was controlled by an electro hydraulic proportional control system,which controls the gap between the parison and the nozzle during the extrusion process by regulating the position of the core bar.Both constant pressure and speed control systems were adopted to control the process of plastic storing and extrusion,and PLC,such as C200H and CQM1,fuzzy modules were adopted.The results show that the part quality of blow molding can be improved greatly.
文摘Many process control systems are a kind of hybrid systems. In order to develop a satisfied control strategy, i. e., to make the whole system satisfy some processing requirements, the knowledge of plant is indispensable. This paper proposes a formal model for the general plant for a kind of process control systems. Based on the model, requirements for the system can be specified from goals, and the controller can be designed according to plant based formal approach . An industrial process control system is used to illustrate our models and methods. Duration Calculus, a real time interval logic, is utilized to specify some characters of the model and development of control program for the exemplified system.
文摘Absolute stability problem has theoretical and engineering importance for control engineering and control theory. In this paper, based on the dimension reducing method, sufficient conditions for the absolute stability of several classes of Lurie control systems are given.
文摘Based on the CMAC (cerebellar model articulation controller) model and Lyapunov stability law,a controller design method using cost function was proposed,the parameter selecting method of the controller was obtained by analyzing the convergence of control algorithms and the stability of the control system.The strategy is applicable to the process where output can be measured and a CMAC model has been obtained.A simulation example is given to demonstrate the correctness and practicality of the proposed strategy.
文摘This paper presents the scheme of the Fuzzy Homogeneous Combustion Control System (FHCCS) and its practical use on site. The operating results of the system show that FHCCS can not only operate normally, but also guarantee the homogeneous combustion in each level of burner and at optimal air coal ratio of each burner. Some engineering problems about FHCCS implementation are discussed in this paper.
文摘After giving a short review of the methods used for detecting and monitoring in general systems, this paper describes the way of communication between computer and Computer Numerical Control (CNC) Machining Center (MC). Based on these, the paper addresses the means of performing in cycle measurement for manufacturing quality, provides an approach of improving the state of manufacturing process by achieving the real time change of control parameters according to the level of manufacturing process, and discusses the technique of implementing in process dimensional errors compensation corresponding to the in cycle measurement. The results of the experiments show that the frame design is successful and the operation is reliable. The system is taking shape nowadays.
文摘Time delay existes widely in various real engineering systems and can result in unsatisfactory performance or even an instability of control systems. Therefore, to investigate the stability for time delay systems is of vitul importance in control theory and its applications. Many researchers have studied the stability criteria of systems with constant delay or bound varying time delay, but few of them studied large time delay or unbound time delay. Large time delay existes commonly in various engineering applications. In this paper, the absolute stability of Lurie type direct control systems and indirect control systems with several time delays are discussed. Based on Lyapunov theory, the new delay dependent absolute stability criteria are derived. In our theorem, time delays can be unbound functions, which shows that the results are less conservative than that of existed criteria.
