Two model reference adaptive system (MRAS) estimators are developed for identifying the parameters of permanent magnet synchronous motors (PMSM) based on the Lyapunov stability theorem and the Popov stability crit...Two model reference adaptive system (MRAS) estimators are developed for identifying the parameters of permanent magnet synchronous motors (PMSM) based on the Lyapunov stability theorem and the Popov stability criterion, respectively. The proposed estimators only need online measurement of currents, voltages, and rotor speed to effectively estimate stator resistance, inductance, and rotor flux-linkage simultaneously. The performance of the estimators is compared and verified through simulations and experiments, which show that the two estimators are simple, have good robustness against parameter variation, and are accurate in parameter tracking. However, the estimator based on the Popov stability criterion, which can overcome parameter variation in a practical system, is superior in terms of response speed and convergence speed since there are both proportional and integral units in the estimator, in contrast to only one integral unit in the estimator based on the Lyapunov stability theorem. In addition, the estimator based on the Popov stability criterion does not need the expertise that is required in designing a Lyapunov function.展开更多
Quadrotor helicopter is emerging as a popular platform for unmanned aerial vehicle re- search, due to its simplicity of structure and maintenance as well as the capability of hovering and vertical take-off and landing...Quadrotor helicopter is emerging as a popular platform for unmanned aerial vehicle re- search, due to its simplicity of structure and maintenance as well as the capability of hovering and vertical take-off and landing. The attitude controller is an important feature of quadrotor helicopter since it allows the vehicle to keep balance and perform the desired maneuver. In this paper, nonlin- ear control strategies including active disturbance rejection control (ADRC), sliding mode control (SMC) and backstepping method are studied and implemented to stabilize the attitude of a 3-DOF hover system. ADRC is an error-driven control law, with extended state observer (ESO) estimating the unmodeled inner dynamics and external disturbance to dynamically compensate their impacts. Meanwhile; both backstepping technique and SMC are developed based on the mathematical model, whose stability is ensured by Lyapunov global stability theorem. Furthermore, the performance of each control algorithm is evaluated by experiments. The results validate effectiveness of the strate- gies for attitude regulation. Finally, the respective characteristics of the three controllers are high- lighted by-comparison, and conclusions are drawn on the basis of the theoretical and experimental a- nalysis.展开更多
Permanent magnet synchronous motor(PMSM) displays chaotic osdllation with certain parameter values, which threatens the secure operation of the power system. To control these unwanted chaotic oscillations, a new con...Permanent magnet synchronous motor(PMSM) displays chaotic osdllation with certain parameter values, which threatens the secure operation of the power system. To control these unwanted chaotic oscillations, a new control scheme which depended on external torque was designed. Based on Lyapunov stability theorem and the matrix theory, several sufficient conditions were derived, which ensured the global asymptotic stability and exponential stability for the chaotic PMSM with uncertain pulse disturbance. The designed controller based on external torque was able to eliminate the chaotic oscillations. A numerical example was given to demonstrate the effectiveness of the proposed results.展开更多
The orbit tracking problem of a free-evolutionary target system in closed quantum systems is solved by changing it into the state transferring problem with the help of unitary transformation.The control law designed b...The orbit tracking problem of a free-evolutionary target system in closed quantum systems is solved by changing it into the state transferring problem with the help of unitary transformation.The control law designed by the Lyapunov stability theorem employs a carefully constructed virtual mechanical quantity P to ensure the system convergence.The virtual mechanical quantity P is chosen by two approaches according to the forms of limit set,where P = —pf is suitable for regular limit set and a new different P is constructed for irregular one.The proposed tracking control theory is demonstrated on a four-level quantum system by means of numerical simulation experiments.展开更多
基金supported by China Scholarship Council, National Natural Science Foundation of China (No. 60634020)Scientific Research Foundation of Education Ministry for the Doctors(No. 20060532026)
文摘Two model reference adaptive system (MRAS) estimators are developed for identifying the parameters of permanent magnet synchronous motors (PMSM) based on the Lyapunov stability theorem and the Popov stability criterion, respectively. The proposed estimators only need online measurement of currents, voltages, and rotor speed to effectively estimate stator resistance, inductance, and rotor flux-linkage simultaneously. The performance of the estimators is compared and verified through simulations and experiments, which show that the two estimators are simple, have good robustness against parameter variation, and are accurate in parameter tracking. However, the estimator based on the Popov stability criterion, which can overcome parameter variation in a practical system, is superior in terms of response speed and convergence speed since there are both proportional and integral units in the estimator, in contrast to only one integral unit in the estimator based on the Lyapunov stability theorem. In addition, the estimator based on the Popov stability criterion does not need the expertise that is required in designing a Lyapunov function.
基金Supported by the National Key Technology R&D Program of China(201011080)
文摘Quadrotor helicopter is emerging as a popular platform for unmanned aerial vehicle re- search, due to its simplicity of structure and maintenance as well as the capability of hovering and vertical take-off and landing. The attitude controller is an important feature of quadrotor helicopter since it allows the vehicle to keep balance and perform the desired maneuver. In this paper, nonlin- ear control strategies including active disturbance rejection control (ADRC), sliding mode control (SMC) and backstepping method are studied and implemented to stabilize the attitude of a 3-DOF hover system. ADRC is an error-driven control law, with extended state observer (ESO) estimating the unmodeled inner dynamics and external disturbance to dynamically compensate their impacts. Meanwhile; both backstepping technique and SMC are developed based on the mathematical model, whose stability is ensured by Lyapunov global stability theorem. Furthermore, the performance of each control algorithm is evaluated by experiments. The results validate effectiveness of the strate- gies for attitude regulation. Finally, the respective characteristics of the three controllers are high- lighted by-comparison, and conclusions are drawn on the basis of the theoretical and experimental a- nalysis.
基金National Natural Science Foundation of China(No.61573095)Natural Science Foundation of Shanghai,China(No.15ZR1401800)
文摘Permanent magnet synchronous motor(PMSM) displays chaotic osdllation with certain parameter values, which threatens the secure operation of the power system. To control these unwanted chaotic oscillations, a new control scheme which depended on external torque was designed. Based on Lyapunov stability theorem and the matrix theory, several sufficient conditions were derived, which ensured the global asymptotic stability and exponential stability for the chaotic PMSM with uncertain pulse disturbance. The designed controller based on external torque was able to eliminate the chaotic oscillations. A numerical example was given to demonstrate the effectiveness of the proposed results.
基金supported by the Doctoral Fund of Ministry of Education of China under Grant No.20103402110044the National Key Basic Research Program under Grant No.2011CBA00200
文摘The orbit tracking problem of a free-evolutionary target system in closed quantum systems is solved by changing it into the state transferring problem with the help of unitary transformation.The control law designed by the Lyapunov stability theorem employs a carefully constructed virtual mechanical quantity P to ensure the system convergence.The virtual mechanical quantity P is chosen by two approaches according to the forms of limit set,where P = —pf is suitable for regular limit set and a new different P is constructed for irregular one.The proposed tracking control theory is demonstrated on a four-level quantum system by means of numerical simulation experiments.