In common design of prediction model-based control method, usually disturbances are not considered in the prediction model as well as the control design. For the control systems with large amplitude or strong disturbances, it is difficult to precisely predict the future outputs according to the conventional prediction model, and thus the desired optimal closed-loop performance will be degraded to some extent. To this end, an improved predictive functional control (PFC) method is developed in this paper by embedding disturbance information into the system model. Here, a composite prediction model is thus obtained by embedding the estimated value of disturbances, where disturbance observer (DOB) is employed to estimate the lumped disturbances. So the influence of disturbances on system is taken into account in optimisation procedure. Finally, considering the speed control problem for permanent magnet synchronous motor (PMSM) servo system, a control scheme based on the improved PFC method is designed to ensure an optimal closed-loop performance even in the presence of disturbances. Simulation and experimental results based on a hardware platform are provided to confirm the effectiveness of the proposed algorithm.

In the study of direct torque control (DTC) of permanent magnet synchronous motor (PMSM), the stator resistance is easily affected by temperature variation and its value varies from time to time. What is more, it will lead to flux ripple. In order to solve the problem of error existing between the set value of the stator flux and the reality, an improved method based on variable parameter PI is proposed to compensate the stator resistance. By constructing the stator flux observer mathematical model of DTC of PMSM and analyzing the stator resistance variation influenced by the stator flux observation, it can be found that the stator resistance is compensated by adjusting PI parameters with time, the flux error will be reduced, and this new method will be testified by MATLAB software. The simulation result shows that the improved stator resistance compensation algorithm has effectively solved the flux ripple problem, decreased the flux error, and achieved the expected control effect.

Considering the speed-regulation problem for permanent magnet synchronous motor (PMSM) servo system, a control scheme based on the improved PFC method is designed to ensure an optimal closed loop performance even in the presence of disturbances. In common design of prediction model based control method, usually disturbances are not considered in the prediction model as well as the control design. To improve the disturbance rejection ability of system, an improved predictive functional control(PFC) method is developed in this paper by embedding disturbance information into the prediction model. Here, a composite prediction model is obtained by introducing the estimated value of disturbances, where disturbance observer (DOB) is employed to estimate the lumped disturbances. So the influence of disturbances on system are taken into account in optimization procedure. Detailed TMS320F2808 DSP experimental results are provided to verify the effectiveness of the proposed method.

The speed regulation problem for permanent magnet synchronous motor (PMSM) servo system is studied in this paper. In order to optimize the control performance of the PMSM servo system, the predictive functional control (PFC) method is introduced in the control design of speed loop. The PFC-based speed control design consists of two steps. A simplified model is employed to predict the future q -axis current of PMSM. Then, an optimal control law is obtained by minimizing a quadratic performance index. However, it is noted that the standard PFC method does not achieve a satisfying effect in the presence of strong disturbances. To this end, an improved PFC method, called the PFC+ESO method, is developed. It introduces extended state observer (ESO) to estimate the lumped disturbances and adds a feedforward compensation item based on the estimated disturbances to the PFC speed controller. Simulation and experiment comparisons are made for these PFC methods and proportional-integral method with antiwindup control method to verify the effectiveness of the proposed methods.

A robust nonlinear disturbance observer based control (NDOBC) approach is proposed for a permanent magnet synchronous motor (PMSM) drive system which is supposed to experience mismatched parameter perturbations as well as unknown load torque disturbances. The proposed control method is expected to obtain fine robustness against parameter uncertainties and external disturbance attenuation performance since it takes into account the full nonlinear dynamics, all possible parameter perturbations, and also the external disturbances in the PMSM system. The final simulation studies and results demonstrate that the proposed method obtains prominent robust tracking performance in the presence of mismatched uncertainties.

The speed-regulation problem for a permanent magnet synchronous motor (PMSM) servo system is studied in this paper. In traditional control design for a speed loop, a first-order model is used to approximately describe the relationship between the reference quadrature axis current and the speed output, i.e. the reference quadrature axis current is regarded as the same as the quadrature axis current. This approximation degrades the closed-loop performance of PMSM system when using a vector control scheme. To this end, a second-order model is built to describe the relationship between the reference quadrature axis current and the speed output for a PMSM system. Based on this second-order model, a standard sliding mode controller is designed for the speed loop. Then, to reduce the chattering and improve the performance of the system, a composite controller consisting of a sliding mode feedback part and a disturbance compensation part based on an extended state observer are developed. Simulation and experiment results and comparisons are given to show the effectiveness of the proposed method.

This paper investigates the problem of position tracking of Permanent Magnet Synchronous Motor (PMSM). On the basis of analyzing the mathematical model of the PMSM, the exact linearization and decoupling of the motor model can be achieved by using the feedback-linearization technique. First, the PMSM position tracking system is transformed to two linear control subsystems by using the feedback linearization. The corresponding finite-time controllers are designed respectively for the two subsystems. Then, the analysis of stability is given for the PMSM closed-loop system. Compared with the corresponding control method of asymptotical stability, the scheme based on the finite-time control can track the desired position signal in finite-time and obtain a better dynamic response and anti-disturbance performance. The simulation results illustrate the effectiveness of the control scheme.

The speed-regulation problem for permanent-magnet synchronous motor (PMSM) servo system is studied in this paper. The predictive functional control (PFC) theory applied to PMSM is concerned. This paper insists on how to implement the PFC method and what kind of performance can be expected from this technology. First, a simplified model of the PMSM servo system is accounted to refine this approach. Then, the controller based on standard PFC method is designed for speed-loop of the system. The optimal control law can be obtained by given a quadratic performance index. And a modified controller, i.e. PFC plus integrator, is also presented to regulate the effects of disturbances. Simulation and experimental comparisons with the PI control method are given to verify the effectiveness of the proposed method.

The speed-regulation problem for a permanent-magnet synchronous motor (PMSM) servo system is studied in this paper. In order to improve the disturbance rejection property of the PMSM, a novel composite controller for the speed-loop is presented. First, an extended state observer (ESO) is introduced to estimate the disturbances of the system. The estimated value is used in the feed-forward compensation design. Second, a continuous feedback-based finite-time control technique is employed for the feedback design. The composite speed controller can be considered as a composition of finite-time proportional feedback plus feed-forward compensation based on ESO (FTP + ESO). Two standard proportional-integral (PI) controllers are employed for two current loops. The closed-loop system of the speed error can be regarded as a first-order finite-time control system with bounded disturbances. Rigorous analysis shows that the proposed scheme can enhance the disturbance rejection property of the closed-loop system. Simulation and experimental comparisons with two other control methods, ie the composite control method with proportional feedback plus feed-forward compensation based on ESO (P + ESO), and the PI control method, are given to verify the effectiveness of the proposed method.

Based on the vector control speed-regulation system of permanent magnet synchronous motor,a compound control method is proposed.First,a disturbance observer is used to estimate the disturbance value of the system which is caused by model parameters change and load change.Then,this estimated value is used to construct a feedforward compensation which is added to the control input.Subsequently,the finite-time control theory is applied to the feedback control design for the forward channel.Finally,a relationship between the parameters of controller and the convergence performance of speed error is given.Simulation results show that the finite-time controller based on disturbance observer has a stronger anti-disturbance ability and a better convergence performance.

Based on the finite-time control technique, the position control problem of Permanent Magnet Synchronous Motor(PMSM) servo system is studied. Using backingstepping method, a control scheme based on feedback linearization and finite-time control technique is proposed for position loop. Rigorous mathematical analysis is given for the close loop system performance in the presence of disturbances. The results show that, compared with the conventional control scheme based on PD and feedback linearization, this method not only makes the position tracking error of the closed loop system with a faster convergence rate, but also makes the boundary of steady-state error smaller by regulating the controller parameters, which means the closed loop system has stronger disturbance rejection property. The simulation results validate the efficiency of this method.