scholarly journals Control of a Digital Galvanometer Scanner Using a Discrete-Time Sliding-Mode Variable-Structure Controller Based on a Decoupled Disturbance Compensator

2021 ◽  
Vol 11 (21) ◽  
pp. 9788
Author(s):  
Guangsheng Chen ◽  
Yunlong Wang
Keyword(s):  
Discrete Time ◽  
Laser Processing ◽  
Sliding Mode ◽  
External Disturbance ◽  
Variable Structure ◽  
Digital System ◽  
Step Response ◽  
Sliding Mode Variable Structure ◽  
Galvanometer Scanner ◽  
Step Responses

Laser processing plays an important role in industrial manufacturing, in which a galvanometer scanner (GS) functions as the core component of the laser processing equipment. With the development of the digital system, the GS based on the digital system finds a broader range of potential application. In order to address the slow step-responses of a GS with disturbance and parameter perturbation, the mathematical model of the motor of the GS is derived and a discrete-time sliding-mode variable-structure controller (DSVC) based on a decoupled disturbance compensator (DDC) (DSVC+DDC) is designed. The step-response performance of a GS is the key factor affecting the quality evaluation of laser processing. Experiments are conducted on the step responses of the motor of the GS on a digital experimental platform. The experiment results show that when guaranteeing a steady-state error within 20 urad and an overshoot of less than 5%, the rise time for step-responses in 1% and 10% of the whole stroke is 1 and 2 ms, decreasing by 23% and 58% compared with the reference performance index, which indicates the effectiveness of the proposed method. The proposed approach can not only compensate for the external disturbance online and improve the step-response speed of the GS, but also relax the traditionally assumed limit of the upper bound of external disturbance to the limit of the change rate of external disturbance, which reduces the difficulty of a practical application. This method has great significance for further applications in high precision machining.

Sliding Mode Variable Structure for Generator Excitation Control Based on the ESO

2011 ◽  
Vol 143-144 ◽  
pp. 108-113
Author(s):  
Yu Hui Zhang ◽  
Chang Bing Han ◽  
Tian Yun Li
Keyword(s):  
Feedback Linearization ◽  
Sliding Mode ◽  
External Disturbance ◽  
Variable Structure ◽  
System Stability ◽  
Excitation System ◽  
Structure Control ◽  
State Observation ◽  
Sliding Mode Variable Structure ◽  
Speed Accuracy

In this paper, a new ESO sliding mode controller that can improve the system stability was designed ,as to the strong nonlinear of generator excitation system and the characteristics of vulnerable to external disturbance, which application of feedback linearization, ESO and sliding model variable structure control theory. Firstly, it realized to linearization for nonlinear mould based on the feedback linearization theory, then it provide dynamic compensation for generator excitation system through constructing extended state observation device (ESO). The methods of factorial is used to design sliding mode switch function, theoretically, it guarantee generator rotor equation with expectations of poles. In order to reduce chattering ,through index near rate and quasi sliding mode control dynamic method to get the sliding control rate, it make the form conciseness, The results of simulation show that the speed , accuracy and stability of system are significantly improved by controller in dynamic and static . Introduction

scholarly journals Attitude stability control of micro-nano satellite orbit maneuver based on bias momentum

2021 ◽  
Vol 2083 (2) ◽  
pp. 022060
Author(s):  
Shuo Xu ◽  
Zhengliang Lu ◽  
Xiang Zhang ◽  
Wenhe Liao
Keyword(s):  
Sliding Mode ◽  
External Disturbance ◽  
Variable Structure ◽  
Stability Control ◽  
Rotational Inertia ◽  
Environmental Disturbance ◽  
Attitude Stability ◽  
Adaptive Sliding Mode ◽  
Robust Adaptive ◽  
Sliding Mode Variable Structure

Abstract In this paper, an attitude stability control strategy based on cold air micro propulsion microsatellite orbital maneuver is designed. Firstly, the influence of environmental disturbance moment, uncertainty of rotational moment of inertia and thrust eccentricity moment on the attitude stability of the micro-nano-satellite is considered, and the attitude dynamics model of the micro-nano-satellite based on biased momentum wheel and magnetic moment device is established. Then, the disturbance moments such as environmental disturbance moments, rotational inertia uncertainty and thrust eccentricity moments are analyzed. In order to suppress the influence of various internal and external disturbance factors on the stability of the micro-nano-satellite during the deorbiting process, a robust adaptive sliding mode variable structure controller is designed. The designed robust adaptive sliding mode controller is able to compensate for various disturbances adaptively. The robust adaptive sliding-mode variable structure controller is designed with a reasonable distribution of torque considering the characteristics of bias momentum wheel control and magnetic control. Finally, numerical simulations are performed, and the simulation results show that the system has good robustness.

scholarly journals Synchronous Generator Rectification System Based on Double Closed-Loop Control of Backstepping and Sliding Mode Variable Structure

Electronics ◽  
2021 ◽  
Vol 10 (15) ◽  
pp. 1832
Author(s):  
Jinfeng Liu ◽  
Xin Qu ◽  
Herbert Ho-Ching Iu
Keyword(s):  
Closed Loop ◽  
Control Structure ◽  
Low Voltage ◽  
Sliding Mode ◽  
Variable Structure ◽  
Synchronous Generator ◽  
Closed Loop Control ◽  
High Current ◽  
Loop Control ◽  
Sliding Mode Variable Structure

Low-voltage and high-current direct current (DC) power supplies are essential for aerospace and shipping. However, its robustness and dynamic response need to be optimized further on some special occasions. In this paper, a novel rectification system platform is built with the low-voltage and high-current permanent magnet synchronous generator (PMSG), in which the DC voltage double closed-loop control system is constructed with the backstepping control method and the sliding mode variable structure (SMVS). In the active component control structure of this system, reasonable virtual control variables are set to obtain the overall structural control variable which satisfied the stability requirements of Lyapunov stability theory. Thus, the fast-tracking and the global adjustment of the system are realized and the robustness is improved. Since the reactive component control structure is simple and no subsystem has to be constructed, the SMVS is used to stabilize the system power factor. By building a simulation model and experimental platform of the 5 V/300 A rectification module based on the PMSG, it is verified that the power factor of the system can reach about 98.5%. When the load mutation occurs, the DC output achieves stability again within 0.02 s, and the system fluctuation rate does not exceed 2%.

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