A new nonlinear variable structure excitation controller is proposed. Its design combines the differential geometry theory and the variable structure controlling theory. The mathematical model in the form of ＂an affm...A new nonlinear variable structure excitation controller is proposed. Its design combines the differential geometry theory and the variable structure controlling theory. The mathematical model in the form of ＂an affme nonlinear system＂ is set up for the control of a large-scale power system. The static and dynamic performances of the nonlinear variable structure controller are simulated. The response of system with the controller proposed is compared to that of the nonlinear optimal controller when the system is subjected to a variety of disturbances. Simulation results show that the nonlinear variable structure excitation controller gives more satisfactorily static and dynamic performance and better robustness.展开更多
A flight control system is designed for a reusable launch vehicle with aerodynamic control surfaces and reaction control system based on a variable-structure control and neural network theory.The control problems of c...A flight control system is designed for a reusable launch vehicle with aerodynamic control surfaces and reaction control system based on a variable-structure control and neural network theory.The control problems of coupling among the channels and the uncertainty of model parameters are solved by using the method.High precise and robust tracking of required attitude angles can be achieved in complicated air space.A mathematical model of reusable launch vehicle is presented first,and then a controller of flight system is presented.Base on the mathematical model,the controller is divided into two parts:variable-structure controller and neural network module which is used to modify the parameters of controller.This control system decouples the lateraldirectional tunnels well with a neural network sliding mode controller and provides a robust and de-coupled tracking for mission angle profiles.After this a control allocation algorithm is employed to allocate the torque moments to aerodynamic control surfaces and thrusters.The final simulation shows that the control system has a good accurate,robust and de-coupled tracking performance.The stable state error is less than 1°,and the overshoot is less than 5%.展开更多
In this paper, structure identification of an uncertain network coupled with complex-variable chaotic systems is in- vestigated. Both the topological structure and the system parameters can be unknown and need to be i...In this paper, structure identification of an uncertain network coupled with complex-variable chaotic systems is in- vestigated. Both the topological structure and the system parameters can be unknown and need to be identified. Based on impulsive stability theory and the Lyapunov function method, an impulsive control scheme combined with an adaptive strategy is adopted to design effective and universal network estimators. The restriction on the impulsive interval is relaxed by adopting an adaptive strategy. Further, the proposed method can monitor the online switching topology effectively. Several numerical simulations are provided to illustrate the effectiveness of the theoretical results.展开更多
The increasing demand on robotic system performance leads to the use of advanced control strategies. A variable structure model-following adaptive control design is presented for the nonlinear robot manipulator sys...The increasing demand on robotic system performance leads to the use of advanced control strategies. A variable structure model-following adaptive control design is presented for the nonlinear robot manipulator systems, when subjected to fast and wide ranges of unknown-but-bounded parameter variations and disturbances. The design does not require any knowledge of a nonlinear robotic system. The system is robust and insensitive to the parameter variation, disturbances, as well as to the unmodeled dynamics. This insensitive property enables the elimination of interactions among the various joints of the robotic manipulator. In the closed loop, the robotic system asymptotically converges to the reference trajectory with a Prescribed transient resPOnse. The problem of chattering is discussed with the introduction of the special approaches: boundary layer, smoothing law, and nonlinear compensation.展开更多
A method of sliding mode variable structure control for the missile body being a time varying system is presented. A remote control guidance law is designed. The method has strong robustness to target＇ s maneuver. To...A method of sliding mode variable structure control for the missile body being a time varying system is presented. A remote control guidance law is designed. The method has strong robustness to target＇ s maneuver. To reduce the chattering phenomena, quasi-sliding mode variable structure control method is used. Simulation results show that the proposed method has small miss distance for any kind of maneuvering targets and requires small control energy.展开更多
A variable structure model reference adaptive control problem for the nonlinear system is studied in this paper. First, according to the relative degree concept of th nonlinear control system an error equation between...A variable structure model reference adaptive control problem for the nonlinear system is studied in this paper. First, according to the relative degree concept of th nonlinear control system an error equation between the outputs of the reference model and the controlled plant is derived. Then, by using the variable structrue control method, an algorithm of variable structure model reference adaptive control is deduced on the basis of a new concept of reaching law. The definition of the SISO system is introduced into the MIMO nonlinear system. Finally, as an example, a pendulum nonlinear control system is simulated to demonstrated the effectiveness of the method. The results show that the method has some advantages: the design is simple, intuitive and easy to be realized in engineering. Besides, it is of practical significance for the synthesis of nonlinear control systems.展开更多
To design the control system for some homing missile so that the autopilot can transfer guidance command correctly and be robust to disturbances, such as the measurement noises and parameter variation caused by areody...To design the control system for some homing missile so that the autopilot can transfer guidance command correctly and be robust to disturbances, such as the measurement noises and parameter variation caused by areodynamic floating. The model reference adaptive control was combined with the variable structure control to design a model reference variable structure (MRVS) control system whose control structure is simple and can be realized easily. The simulation results indicate that MRVS can complete the task of transferring guidance command and suppress the distrubances effectively.展开更多
Sliding mode control problem of a class of Ito^ type partial differential equations with delay is probed. The variable structure controller is designed. The existence of motion of sliding mode is shown. And the charac...Sliding mode control problem of a class of Ito^ type partial differential equations with delay is probed. The variable structure controller is designed. The existence of motion of sliding mode is shown. And the character of invariance of sliding control system about uncertainty on the sliding switching surface and stability are analyzed.展开更多
An attitude control algorithm for reusable launch vehicle(RLV) in reentry phase is proposed based on sliding mode variable structure control technique.The aerodynamic characteristics of RLV vary rapidly,and the seriou...An attitude control algorithm for reusable launch vehicle(RLV) in reentry phase is proposed based on sliding mode variable structure control technique.The aerodynamic characteristics of RLV vary rapidly,and the serious uncertainties and nonlinearities exist in the reentry flight phase.As an example,American X-34 technology demonstrator is investigated.The chattering brought by the variable structure control technique is eliminated efficiently by choosing a suitable reaching law and a sign function.A control mode of reaction control system is presented based on the RCS scheme of X-34 vehicle.As two different attitude control effectors,aerosurfaces and RCS,are employed in the reentry flight phase,a composite control strategy based on the dynamic pressure variety is presented.Also,an actuator model and a RCS thruster model are built.Analysis and nonlinear simulation results show that the sliding mode variable structure controller achieves better performance,the overshoot and steady-state error are only 0.7% and 0.04° respectively.展开更多
It is an innovative try to control hypersonic bank-to-turn missiles using the deflectable nose and flaps. The higher control efficiency,faster response,better stability and compactness of the nose control are shown by...It is an innovative try to control hypersonic bank-to-turn missiles using the deflectable nose and flaps. The higher control efficiency,faster response,better stability and compactness of the nose control are shown by comparing the deflectable nose control with the normal tail fin control. A mathematical model of the missile,which is time-varying,nonlinear and strong coupling,is establihsed by multi-body dynamics to be used for designing the controller. A robust controller of deflectable nose control is designed by variable structure control theory,selecting sliding mode surfaces with tracking error and its integral function,and considering parameter disturbance of the model. The simulation results show the controller can response quickly and track precisely. The deflectable nose control is proper for the bank-to-turn missile.展开更多
The nonlinear dynamic system of spacecraft with uncertainty and coupling is analyzed and its general dynamical equation is given.The decoupling-ability and controllability are proved.Aiming at this system,a new nonlin...The nonlinear dynamic system of spacecraft with uncertainty and coupling is analyzed and its general dynamical equation is given.The decoupling-ability and controllability are proved.Aiming at this system,a new nonlinear decoupling controlling method is put forward by synthetically using the variable structure and fuzzy theory.The simulation results show that this method is effective in tracking performances under the existence of uncertainty and outer disturbance.展开更多
文摘A new nonlinear variable structure excitation controller is proposed. Its design combines the differential geometry theory and the variable structure controlling theory. The mathematical model in the form of ＂an affme nonlinear system＂ is set up for the control of a large-scale power system. The static and dynamic performances of the nonlinear variable structure controller are simulated. The response of system with the controller proposed is compared to that of the nonlinear optimal controller when the system is subjected to a variety of disturbances. Simulation results show that the nonlinear variable structure excitation controller gives more satisfactorily static and dynamic performance and better robustness.
文摘A flight control system is designed for a reusable launch vehicle with aerodynamic control surfaces and reaction control system based on a variable-structure control and neural network theory.The control problems of coupling among the channels and the uncertainty of model parameters are solved by using the method.High precise and robust tracking of required attitude angles can be achieved in complicated air space.A mathematical model of reusable launch vehicle is presented first,and then a controller of flight system is presented.Base on the mathematical model,the controller is divided into two parts:variable-structure controller and neural network module which is used to modify the parameters of controller.This control system decouples the lateraldirectional tunnels well with a neural network sliding mode controller and provides a robust and de-coupled tracking for mission angle profiles.After this a control allocation algorithm is employed to allocate the torque moments to aerodynamic control surfaces and thrusters.The final simulation shows that the control system has a good accurate,robust and de-coupled tracking performance.The stable state error is less than 1°,and the overshoot is less than 5%.
基金Project supported by the Tianyuan Special Funds of the National Natural Science Foundation of China(Grant No.11226242)the Natural Science Foundation of Jiangxi Province of China(Grant No.20122BAB211006)
文摘In this paper, structure identification of an uncertain network coupled with complex-variable chaotic systems is in- vestigated. Both the topological structure and the system parameters can be unknown and need to be identified. Based on impulsive stability theory and the Lyapunov function method, an impulsive control scheme combined with an adaptive strategy is adopted to design effective and universal network estimators. The restriction on the impulsive interval is relaxed by adopting an adaptive strategy. Further, the proposed method can monitor the online switching topology effectively. Several numerical simulations are provided to illustrate the effectiveness of the theoretical results.
文摘The increasing demand on robotic system performance leads to the use of advanced control strategies. A variable structure model-following adaptive control design is presented for the nonlinear robot manipulator systems, when subjected to fast and wide ranges of unknown-but-bounded parameter variations and disturbances. The design does not require any knowledge of a nonlinear robotic system. The system is robust and insensitive to the parameter variation, disturbances, as well as to the unmodeled dynamics. This insensitive property enables the elimination of interactions among the various joints of the robotic manipulator. In the closed loop, the robotic system asymptotically converges to the reference trajectory with a Prescribed transient resPOnse. The problem of chattering is discussed with the introduction of the special approaches: boundary layer, smoothing law, and nonlinear compensation.
文摘A method of sliding mode variable structure control for the missile body being a time varying system is presented. A remote control guidance law is designed. The method has strong robustness to target＇ s maneuver. To reduce the chattering phenomena, quasi-sliding mode variable structure control method is used. Simulation results show that the proposed method has small miss distance for any kind of maneuvering targets and requires small control energy.
文摘A variable structure model reference adaptive control problem for the nonlinear system is studied in this paper. First, according to the relative degree concept of th nonlinear control system an error equation between the outputs of the reference model and the controlled plant is derived. Then, by using the variable structrue control method, an algorithm of variable structure model reference adaptive control is deduced on the basis of a new concept of reaching law. The definition of the SISO system is introduced into the MIMO nonlinear system. Finally, as an example, a pendulum nonlinear control system is simulated to demonstrated the effectiveness of the method. The results show that the method has some advantages: the design is simple, intuitive and easy to be realized in engineering. Besides, it is of practical significance for the synthesis of nonlinear control systems.
文摘To design the control system for some homing missile so that the autopilot can transfer guidance command correctly and be robust to disturbances, such as the measurement noises and parameter variation caused by areodynamic floating. The model reference adaptive control was combined with the variable structure control to design a model reference variable structure (MRVS) control system whose control structure is simple and can be realized easily. The simulation results indicate that MRVS can complete the task of transferring guidance command and suppress the distrubances effectively.
基金Supported by the national natural science foundation (60574042)
文摘Sliding mode control problem of a class of Ito^ type partial differential equations with delay is probed. The variable structure controller is designed. The existence of motion of sliding mode is shown. And the character of invariance of sliding control system about uncertainty on the sliding switching surface and stability are analyzed.
文摘An attitude control algorithm for reusable launch vehicle(RLV) in reentry phase is proposed based on sliding mode variable structure control technique.The aerodynamic characteristics of RLV vary rapidly,and the serious uncertainties and nonlinearities exist in the reentry flight phase.As an example,American X-34 technology demonstrator is investigated.The chattering brought by the variable structure control technique is eliminated efficiently by choosing a suitable reaching law and a sign function.A control mode of reaction control system is presented based on the RCS scheme of X-34 vehicle.As two different attitude control effectors,aerosurfaces and RCS,are employed in the reentry flight phase,a composite control strategy based on the dynamic pressure variety is presented.Also,an actuator model and a RCS thruster model are built.Analysis and nonlinear simulation results show that the sliding mode variable structure controller achieves better performance,the overshoot and steady-state error are only 0.7% and 0.04° respectively.
基金Innovation Foundation of China Astronautic Science and Technology (07XE0153)
文摘It is an innovative try to control hypersonic bank-to-turn missiles using the deflectable nose and flaps. The higher control efficiency,faster response,better stability and compactness of the nose control are shown by comparing the deflectable nose control with the normal tail fin control. A mathematical model of the missile,which is time-varying,nonlinear and strong coupling,is establihsed by multi-body dynamics to be used for designing the controller. A robust controller of deflectable nose control is designed by variable structure control theory,selecting sliding mode surfaces with tracking error and its integral function,and considering parameter disturbance of the model. The simulation results show the controller can response quickly and track precisely. The deflectable nose control is proper for the bank-to-turn missile.
文摘The nonlinear dynamic system of spacecraft with uncertainty and coupling is analyzed and its general dynamical equation is given.The decoupling-ability and controllability are proved.Aiming at this system,a new nonlinear decoupling controlling method is put forward by synthetically using the variable structure and fuzzy theory.The simulation results show that this method is effective in tracking performances under the existence of uncertainty and outer disturbance.
