The stability of the motion control system is one of the decisive factors of the control quality for Autonomous Underwater Vehicle(AUV).The divergence of control,which the unstable system may be brought about,is fat...The stability of the motion control system is one of the decisive factors of the control quality for Autonomous Underwater Vehicle(AUV).The divergence of control,which the unstable system may be brought about,is fatal to the operation of AUV.The stability analysis of the PD and S-surface speed controllers based on the Lyapunov's direct method is proposed in this paper.After decoupling the six degree-of-freedom(DOF)motions of the AUV,the axial dynamic behavior is discussed and the condition is deduced,in which the parameters selection within stability domain can guarantee the system asymptotically stable.The experimental results in a tank and on the sea have successfully verified the algorithm reliability,which can be served as a good reference for analyzing other AUV nonlinear control systems.展开更多
According to the Rodrigues parameter and the internal model principle,an adaptive state feedback control law is proposed for a rigid spacecraft with inertia uncertainty and exotic disturbances generated by an unknown ...According to the Rodrigues parameter and the internal model principle,an adaptive state feedback control law is proposed for a rigid spacecraft with inertia uncertainty and exotic disturbances generated by an unknown nonlinear exosystem.The uncertainty of parameters is treated by an adaptive control law.And a new internal model is proposed to estimate the exotic disturbances.By using the Lyapunov analysis method,the control law is designed to ensure that the system's state variables asymptotically converge to stable,and the disturbances can be completely rejected.Finally,numerical simulations are included to demonstrate the performance of the presented controller.展开更多
The control problem for the multivariable and nonlinear dynamics of unmanned aerial vehicles and micro-satellites is solved with the use of a flatness-based control approach which is implemented in successive loops.Th...The control problem for the multivariable and nonlinear dynamics of unmanned aerial vehicles and micro-satellites is solved with the use of a flatness-based control approach which is implemented in successive loops.The state-space model of(i)unmanned aerial vehicles and(ii)micro-satellites is separated into two subsystems,which are connected between them in cascading loops.Each one of these subsystems can be viewed independently as a differentially flat system and control about it can be performed with inversion of its dynamics as in the case of input–output linearized flat systems.The state variables of the second subsystem become virtual control inputs for the first subsystem.In turn,exogenous control inputs are applied to the first subsystem.The whole control method is implemented in two successive loops and its global stability properties are also proven through Lyapunov stability analysis.The validity of the control method is confirmed in two case studies:(a)control and trajectories tracking for the autonomous octocopter,(ii)control of the attitude dynamics of micro-satellites.展开更多
The article proposes a nonlinear optimal(H-infinity)control approach for the model of a tracked robotic vehicle.The kinematic model of such a tracked vehicle takes into account slippage effects due to the contact of t...The article proposes a nonlinear optimal(H-infinity)control approach for the model of a tracked robotic vehicle.The kinematic model of such a tracked vehicle takes into account slippage effects due to the contact of the tracks with the ground.To solve the related control problem,the dynamic model of the vehicle undergoes first approximate linearization around a temporary operating point which is updated at each iteration of the control algorithm.The linearization process relies on first-order Taylor series expansion and on the computation of the Jacobian matrices of the state-space model of the vehicle.For the approximately linearized description of the tracked vehicle a stabilizing H-infinity feedback controller is designed.To compute the controller’s feedback gains an algebraic Riccati equation is solved at each time-step of the control method.The stability properties of the control scheme are proven through Lyapunov analysis.It is also demonstrated that the control method retains the advantages of linear optimal control,that is fast and accurate tracking of reference setpoints under moderate variations of the control inputs.展开更多
Attitude control and stabilization of micro-satellites is a nontrivial problem due to the highly nonlinear and multivariable structure of the satellites'state-space model.In this paper,a novel nonlinear optimal(H-...Attitude control and stabilization of micro-satellites is a nontrivial problem due to the highly nonlinear and multivariable structure of the satellites'state-space model.In this paper,a novel nonlinear optimal(H-infinity)control approach is developed for this control problem.The dynamic model of the satellite's attitude dynamics undergoesfirst approximate linearization around a temporary operating point which is updated at each iteration of the control algorithm.The linearization process relies on first-order Taylor series expansion and on the computation of the Jacobian matrices of the state-space model of the satellite's attitude dynamics.For the approximately linearized description of the satellite's attitude a stabilizing H-infinity feedback controller is designed.To compute the controller's feedback gains,an algebraic Riccati equation is solved at each time-step of the control method.The stability properties of the control scheme are proven through Lyapunov analysis.It is also demonstrated that the control method retains the advantages of linear optimal control that is fast and accurate tracking of the reference setpoints under moderate variations of the control inputs.展开更多
The pump is one of the most important energy consuming devices in an energy system. The axial force on a centrifugal pump is an important factor for improving the operation stability and the service life. Based on the...The pump is one of the most important energy consuming devices in an energy system. The axial force on a centrifugal pump is an important factor for improving the operation stability and the service life. Based on the Bernoulli’s equation, the formulas of the axial clearance are derived theoretically. The relationship between the impeller axial force, the clearance leakage flow rate and the axial clearance is obtained. The motion differential equation of the axial-auto-balanced impeller is established by the number axis modeling method. The asymptotic stability of the impeller is evaluated by the Lyapunov stability analysis. The transient simulation of the axial-auto-balanced impeller is carried out by the method of the computational fluid dynamics (CFD) with the dynamic mesh technology. The time required for the impeller to reach the stable state under different conditions is calculated. The effective values of the axial force are determined. This research is useful to improve the operation stability of the pump.展开更多
基金supported by the National High Technology Development Program of China(863Program,Grant No.2008AA092301)the Fundamental Research Foundation of Harbin Engineering University(Grant No.HEUFT08001)the Postdoctoral Science Foundation of China(Grant No.20080440838)
文摘The stability of the motion control system is one of the decisive factors of the control quality for Autonomous Underwater Vehicle(AUV).The divergence of control,which the unstable system may be brought about,is fatal to the operation of AUV.The stability analysis of the PD and S-surface speed controllers based on the Lyapunov's direct method is proposed in this paper.After decoupling the six degree-of-freedom(DOF)motions of the AUV,the axial dynamic behavior is discussed and the condition is deduced,in which the parameters selection within stability domain can guarantee the system asymptotically stable.The experimental results in a tank and on the sea have successfully verified the algorithm reliability,which can be served as a good reference for analyzing other AUV nonlinear control systems.
基金National Natural Science Foundation of China(No.61663030,No.61663032)Natural Science Foundation of Jiangxi Province,China(No.20142BAB207021)+4 种基金the Innovation Fund Designated for Graduate Students of Jiangxi Province(YC2016-S350)the Foundation of Jiangxi Educational Committee,China(No.GJJ150753)the Open Fund of Key Laboratory of Image Processing and Pattern Recognition of Jiangxi Province,China(Nanchang Hangkong University)(No.TX201404003)Key Laboratory of Nondestructive Testing(Nanchang Hangkong University),Ministry of Education,China(No.ZD29529005)The Twelfth "Sanxiao" College Students Extracurricular Innovation and Entrepreneurship Practice and Training Project of Nanchang Hangkong University,China(No.2017ZD021)
文摘According to the Rodrigues parameter and the internal model principle,an adaptive state feedback control law is proposed for a rigid spacecraft with inertia uncertainty and exotic disturbances generated by an unknown nonlinear exosystem.The uncertainty of parameters is treated by an adaptive control law.And a new internal model is proposed to estimate the exotic disturbances.By using the Lyapunov analysis method,the control law is designed to ensure that the system's state variables asymptotically converge to stable,and the disturbances can be completely rejected.Finally,numerical simulations are included to demonstrate the performance of the presented controller.
文摘The control problem for the multivariable and nonlinear dynamics of unmanned aerial vehicles and micro-satellites is solved with the use of a flatness-based control approach which is implemented in successive loops.The state-space model of(i)unmanned aerial vehicles and(ii)micro-satellites is separated into two subsystems,which are connected between them in cascading loops.Each one of these subsystems can be viewed independently as a differentially flat system and control about it can be performed with inversion of its dynamics as in the case of input–output linearized flat systems.The state variables of the second subsystem become virtual control inputs for the first subsystem.In turn,exogenous control inputs are applied to the first subsystem.The whole control method is implemented in two successive loops and its global stability properties are also proven through Lyapunov stability analysis.The validity of the control method is confirmed in two case studies:(a)control and trajectories tracking for the autonomous octocopter,(ii)control of the attitude dynamics of micro-satellites.
基金supported by the Research“Advances in Applied Nonlinear Optimal Control”under Grant No.6065。
文摘The article proposes a nonlinear optimal(H-infinity)control approach for the model of a tracked robotic vehicle.The kinematic model of such a tracked vehicle takes into account slippage effects due to the contact of the tracks with the ground.To solve the related control problem,the dynamic model of the vehicle undergoes first approximate linearization around a temporary operating point which is updated at each iteration of the control algorithm.The linearization process relies on first-order Taylor series expansion and on the computation of the Jacobian matrices of the state-space model of the vehicle.For the approximately linearized description of the tracked vehicle a stabilizing H-infinity feedback controller is designed.To compute the controller’s feedback gains an algebraic Riccati equation is solved at each time-step of the control method.The stability properties of the control scheme are proven through Lyapunov analysis.It is also demonstrated that the control method retains the advantages of linear optimal control,that is fast and accurate tracking of reference setpoints under moderate variations of the control inputs.
文摘Attitude control and stabilization of micro-satellites is a nontrivial problem due to the highly nonlinear and multivariable structure of the satellites'state-space model.In this paper,a novel nonlinear optimal(H-infinity)control approach is developed for this control problem.The dynamic model of the satellite's attitude dynamics undergoesfirst approximate linearization around a temporary operating point which is updated at each iteration of the control algorithm.The linearization process relies on first-order Taylor series expansion and on the computation of the Jacobian matrices of the state-space model of the satellite's attitude dynamics.For the approximately linearized description of the satellite's attitude a stabilizing H-infinity feedback controller is designed.To compute the controller's feedback gains,an algebraic Riccati equation is solved at each time-step of the control method.The stability properties of the control scheme are proven through Lyapunov analysis.It is also demonstrated that the control method retains the advantages of linear optimal control that is fast and accurate tracking of the reference setpoints under moderate variations of the control inputs.
基金the National Natural Science Foundation ofChina(Grant Nos.51909131,52079142 and 51836010)。
文摘The pump is one of the most important energy consuming devices in an energy system. The axial force on a centrifugal pump is an important factor for improving the operation stability and the service life. Based on the Bernoulli’s equation, the formulas of the axial clearance are derived theoretically. The relationship between the impeller axial force, the clearance leakage flow rate and the axial clearance is obtained. The motion differential equation of the axial-auto-balanced impeller is established by the number axis modeling method. The asymptotic stability of the impeller is evaluated by the Lyapunov stability analysis. The transient simulation of the axial-auto-balanced impeller is carried out by the method of the computational fluid dynamics (CFD) with the dynamic mesh technology. The time required for the impeller to reach the stable state under different conditions is calculated. The effective values of the axial force are determined. This research is useful to improve the operation stability of the pump.