In order to meet the precision requirements and tracking performance of the continuous rotary motor electro-hydraulic servo system under unknown strong non-linear and uncertain strong disturbance factors,such as dynam...In order to meet the precision requirements and tracking performance of the continuous rotary motor electro-hydraulic servo system under unknown strong non-linear and uncertain strong disturbance factors,such as dynamic uncertainty and parameter perturbation,an improved active disturbance rejection control(ADRC)strategy was proposed.The state space model of the fifth order closed-loop system was established based on the principle of valve-controlled hydraulic motor.Then the three parts of ADRC were improved by parameter perturbation and external disturbance;the fast tracking differentiator was introduced into linear and non-linear combinations;the nonlinear state error feedback was proposed using synovial control;the extended state observer was determined by nonlinear compensation.In addition,the grey wolf algorithm was used to set the parameters of the three parts.The simulation and experimental results show that the improved ADRC can realize the system frequency 12 Hz when the tracking accuracy and response speed meet the requirements of double ten indexes,which lay foundation for the motor application.展开更多
In order to suppress the periodic interference of the continuous rotary electro-hydraulic servo motor,this paper makes the motor tracking the periodic signals with high accuracy,and improves the influence of friction ...In order to suppress the periodic interference of the continuous rotary electro-hydraulic servo motor,this paper makes the motor tracking the periodic signals with high accuracy,and improves the influence of friction interference to the performance of continuous rotary electro-hydraulic servo motor.The mathematic model of the electro-hydraulic position servo system of the continuous rotary motor was established,and the compound control method was adopted based on the repetitive control,feed forward and PID to suppress the friction interference.Through the simulation,the result confirms that the compound control method decreases the tracking error of the system,increases the robust performance of the system and improves the performance of the continuous rotary electro-hydraulic servo motor.展开更多
Attitude control system is one of the most important subsystems in a spacecraft.As a key actuator,the control moment gyroscope(CMG)mainly determines the performance of attitude control system.Whereas,the control accur...Attitude control system is one of the most important subsystems in a spacecraft.As a key actuator,the control moment gyroscope(CMG)mainly determines the performance of attitude control system.Whereas,the control accuracy and output torque smoothness of the CMG depends more on its gimbal servo system.Considering the constraints of size,mass and power consumption for a small satellite,here,a mini-CMG is designed,in which the gimbal servo system is driven by an ultrasonic motor.The good performances of the CMG are obtained by both the ultrasonic motor and the rotary inductosyn.The direct drive of gimbal improves its dynamic performance,with the output bandwidth above 20 Hz.The angular and speed closed-loop control obtains the 0.02°/s gimbal rate,and the output torque resolution better than 2×10^(-3) N·m.The ultrasonic motor provides 1.0N·m self-lock torque during power-off,with 12arc-second position accuracy.展开更多
With the background of the control of additional mechanical force droplet transfer in MIG/MAG welding, regarding the AC servo motor as core, a novel oscillating wire feeding system has been developed with excellent pe...With the background of the control of additional mechanical force droplet transfer in MIG/MAG welding, regarding the AC servo motor as core, a novel oscillating wire feeding system has been developed with excellent performances of control and dynamic acceleration which is tested. System constitution and operation principle are introduced in this paper. Influences of parameters on dynamic acceleration performance are analyzed and discussed emphatically, such as oscillating frequency, oscillating amplitude and draw-back speed. Experimental result indicates that according to the technique of welding control, the novel wire feeding system responds rapidly to various kinds of control orders of wire feeding and draw-back, and realizes flexible control of welding wire axial movement, including dynamic shifting,oscillating and so on.展开更多
Recent technological advancements have propelled remarkable progress in servo systems,resulting in their extensive utilization across various high-end applications.A comprehensive review of high-quality servo system t...Recent technological advancements have propelled remarkable progress in servo systems,resulting in their extensive utilization across various high-end applications.A comprehensive review of high-quality servo system technologies,focusing specifically on electrical motor topologies and control strategies is presented.In terms of motor topology,this study outlines the mainstream servo motors used across different periods,as well as the latest theories and technologies surrounding contemporary servo motors.In terms of control strategies,two well-established approaches are presented:field-oriented control and direct torque control.Additionally,it discusses advanced control strategies employed in servo systems,such as model predictive control(MPC)and fault tolerance control,among others.展开更多
The current research of electro-hydraulic servo valves mainly focuses on the vibration, pressure oscillating and source of noise. Unfortunately, literatures relating to the study of the influence of the magnetic reluc...The current research of electro-hydraulic servo valves mainly focuses on the vibration, pressure oscillating and source of noise. Unfortunately, literatures relating to the study of the influence of the magnetic reluctances of the magnetic elements are rarely available. This paper aims to analyze the influence of the magnetic reluctances of the magnetic elements on torque motor. Considering these magnetic reluctances ignored in previous literatures, a new mathematical model of servo valve torque motor is developed and proposed based on the fundamental laws of electromagnetism. By using this new mathematical model and the previous models, electromagnetic torque constant and magnetic spring stiffness are evaluated for a given set of torque motor parameters. A computer simulation by using AMESim software is also performed for the same set of torque motor parameters to verify the proposed model. The theoretical results of electromagnetic torque constant and magnetic spring stiffness evaluated by the proposed model render closer agreement with the simulation results than those evaluated by the previous models. In addition, an experimental measurement of the magnetic flux densities in the air-gaps is carried out by using SFL218 servo valve torque motor. Compared with the theoretical results of the magnetic flux densities in the air-gaps evaluated by the previous models, the theoretical results evaluated by the proposed model also show better agreement with the experimental data. The proposed model shows the influence of the magnetic reluctances of the magnetic elements on the servo valve torque motor, and offers modified and analytical expressions to electromagnetic torque constant and magnetic spring stiffness. These modified and analytical expressions could provide guidance more accurately for a linear control design approach and sensitivity analysis on electro-hydraulic servo valves than the previous expressions.展开更多
In allusion to the problem of friction,leakage,vibration and noise existing in continuous rotary motor electro-hydraulic servo system,highly nonlinearity and uncertainties affecting the system performance,based on the...In allusion to the problem of friction,leakage,vibration and noise existing in continuous rotary motor electro-hydraulic servo system,highly nonlinearity and uncertainties affecting the system performance,based on the transfer function of electro-hydraulic servo system,a kind of Pol-Ind friction model is proposed.The parameters of Pol-Ind friction model are identified and the accurate mathematical model of friction torque is obtained by experiment.The self-correcting wavelet neural network(WNN)controller is proposed,and Adam optimization algorithm is used to perform gradient optimization on scale factor and displacement factor in wavelet basis function,so as to improve the speed and precision of parameter optimization.Through comparative simulation analysis,it is clearly that the self-correcting WNN controller can effectively improve the frequency response and tracking accuracy of continuous rotary motor electro-hydraulic servo system.展开更多
In order to study the influence of inlet and outlet pressure difference and triangular buffer groove on the internal leakage of continuous rotary electro-hydraulic servo motor,the flow field model of motor with and wi...In order to study the influence of inlet and outlet pressure difference and triangular buffer groove on the internal leakage of continuous rotary electro-hydraulic servo motor,the flow field model of motor with and without triangular groove is established respectively.The mesh model is divided.The pressure distribution of the internal flow field under different pressure difference is analyzed by Fluent.Then,the gap leakage under different pressure difference is calculated,and the leakage curve is obtained.Finally,continuous rotary electro-hydraulic servo motor experimental system is built to conduct the internal leakage test,and the leakage under different pressure difference is measured and compared with the simulation results.The results show that the occurrence of leakage in the motor can be reduced by setting the triangular buffer groove on the flow plate,the simulation and experimental results are consistent.It can be concluded that the larger the pressure difference between the inlet and the outlet of the motor,the larger the gap leakage.The research lays foundation for the application of continuous rotary electro-hydraulic servo motor.展开更多
This paper proposes a method that rotation angle of servo motor and distance values of ultrasonic sensor are used for tracking an object in real-time while the robot keeps regular distance.Object detection distance wi...This paper proposes a method that rotation angle of servo motor and distance values of ultrasonic sensor are used for tracking an object in real-time while the robot keeps regular distance.Object detection distance widens by using ultrasonic sensors and object recognition,and movement of robot is controlled by angle of servo motor and distance of ultrasonic sensors.Not adopting the existing tracking methods:camera,laser-infrared(LRF)and many ultrasonic sensors,the proposed method proves that it is possible to track object using ultrasonic sensor and servo motor.Trajectory of robot is represented and analysed according to movement of object in limited conditions.展开更多
The time domain guideposts requirements of a pump-motor system is transfered into a series of constraints which express the robust performance upper bound and regional poles limits of the closed loop system. Then the ...The time domain guideposts requirements of a pump-motor system is transfered into a series of constraints which express the robust performance upper bound and regional poles limits of the closed loop system. Then the servo system control problem is transferred into the problem of robust performance optimizing under regional poles constrains described by linear matrix inequality （LMI）. These LMIs are easy to solve through the Matlab LMI-toolbox. Simulations indicate that the controller has excellent dynamic, static and disturbance rejection performance, and the control system is robust and has perfect H2 performance to the bounded external torque disturbance.展开更多
To change the current phenomenon of ＂Being an armchair strategist＂ in the research of a stepping motor, the virtual simu- lation system of stepping motor was developed using virtual reality technique. The basic prin...To change the current phenomenon of ＂Being an armchair strategist＂ in the research of a stepping motor, the virtual simu- lation system of stepping motor was developed using virtual reality technique. The basic principle of stepping motor was expounded. The development strategy of the simulation software is introduced. Some key problems and their solutions, including coordinate transformation of rotor and order of on-off electricity for stator, were put forward in system development. Finally, there are three virtual simulation examples of the on-off electricity way in this paper. This work provides a valuable auxiliary tool for the study of the stepping motor.展开更多
基金Project(51975164)supported by the National Natural Science Foundation of ChinaProject(2019-KYYWF-0205)supported by the Fundamental Research Foundation for Universities of Heilongjiang Province,China。
文摘In order to meet the precision requirements and tracking performance of the continuous rotary motor electro-hydraulic servo system under unknown strong non-linear and uncertain strong disturbance factors,such as dynamic uncertainty and parameter perturbation,an improved active disturbance rejection control(ADRC)strategy was proposed.The state space model of the fifth order closed-loop system was established based on the principle of valve-controlled hydraulic motor.Then the three parts of ADRC were improved by parameter perturbation and external disturbance;the fast tracking differentiator was introduced into linear and non-linear combinations;the nonlinear state error feedback was proposed using synovial control;the extended state observer was determined by nonlinear compensation.In addition,the grey wolf algorithm was used to set the parameters of the three parts.The simulation and experimental results show that the improved ADRC can realize the system frequency 12 Hz when the tracking accuracy and response speed meet the requirements of double ten indexes,which lay foundation for the motor application.
基金supported by the Postdoctoral Project of Heilongjiang Province
文摘In order to suppress the periodic interference of the continuous rotary electro-hydraulic servo motor,this paper makes the motor tracking the periodic signals with high accuracy,and improves the influence of friction interference to the performance of continuous rotary electro-hydraulic servo motor.The mathematic model of the electro-hydraulic position servo system of the continuous rotary motor was established,and the compound control method was adopted based on the repetitive control,feed forward and PID to suppress the friction interference.Through the simulation,the result confirms that the compound control method decreases the tracking error of the system,increases the robust performance of the system and improves the performance of the continuous rotary electro-hydraulic servo motor.
基金supported by the National Natural Science Foundation of China(No.51575260)the Fundamental Research Funds for the Central Universities(No.NJ20160001)
文摘Attitude control system is one of the most important subsystems in a spacecraft.As a key actuator,the control moment gyroscope(CMG)mainly determines the performance of attitude control system.Whereas,the control accuracy and output torque smoothness of the CMG depends more on its gimbal servo system.Considering the constraints of size,mass and power consumption for a small satellite,here,a mini-CMG is designed,in which the gimbal servo system is driven by an ultrasonic motor.The good performances of the CMG are obtained by both the ultrasonic motor and the rotary inductosyn.The direct drive of gimbal improves its dynamic performance,with the output bandwidth above 20 Hz.The angular and speed closed-loop control obtains the 0.02°/s gimbal rate,and the output torque resolution better than 2×10^(-3) N·m.The ultrasonic motor provides 1.0N·m self-lock torque during power-off,with 12arc-second position accuracy.
基金NationalNatureScienceFoundation (No .5 9775 0 62 )
文摘With the background of the control of additional mechanical force droplet transfer in MIG/MAG welding, regarding the AC servo motor as core, a novel oscillating wire feeding system has been developed with excellent performances of control and dynamic acceleration which is tested. System constitution and operation principle are introduced in this paper. Influences of parameters on dynamic acceleration performance are analyzed and discussed emphatically, such as oscillating frequency, oscillating amplitude and draw-back speed. Experimental result indicates that according to the technique of welding control, the novel wire feeding system responds rapidly to various kinds of control orders of wire feeding and draw-back, and realizes flexible control of welding wire axial movement, including dynamic shifting,oscillating and so on.
基金Supported by the National Natural Science Foundation of China under Major Project 51991380.
文摘Recent technological advancements have propelled remarkable progress in servo systems,resulting in their extensive utilization across various high-end applications.A comprehensive review of high-quality servo system technologies,focusing specifically on electrical motor topologies and control strategies is presented.In terms of motor topology,this study outlines the mainstream servo motors used across different periods,as well as the latest theories and technologies surrounding contemporary servo motors.In terms of control strategies,two well-established approaches are presented:field-oriented control and direct torque control.Additionally,it discusses advanced control strategies employed in servo systems,such as model predictive control(MPC)and fault tolerance control,among others.
基金Supported by National Natural Science Foundation of China(Grant No.50975055)
文摘The current research of electro-hydraulic servo valves mainly focuses on the vibration, pressure oscillating and source of noise. Unfortunately, literatures relating to the study of the influence of the magnetic reluctances of the magnetic elements are rarely available. This paper aims to analyze the influence of the magnetic reluctances of the magnetic elements on torque motor. Considering these magnetic reluctances ignored in previous literatures, a new mathematical model of servo valve torque motor is developed and proposed based on the fundamental laws of electromagnetism. By using this new mathematical model and the previous models, electromagnetic torque constant and magnetic spring stiffness are evaluated for a given set of torque motor parameters. A computer simulation by using AMESim software is also performed for the same set of torque motor parameters to verify the proposed model. The theoretical results of electromagnetic torque constant and magnetic spring stiffness evaluated by the proposed model render closer agreement with the simulation results than those evaluated by the previous models. In addition, an experimental measurement of the magnetic flux densities in the air-gaps is carried out by using SFL218 servo valve torque motor. Compared with the theoretical results of the magnetic flux densities in the air-gaps evaluated by the previous models, the theoretical results evaluated by the proposed model also show better agreement with the experimental data. The proposed model shows the influence of the magnetic reluctances of the magnetic elements on the servo valve torque motor, and offers modified and analytical expressions to electromagnetic torque constant and magnetic spring stiffness. These modified and analytical expressions could provide guidance more accurately for a linear control design approach and sensitivity analysis on electro-hydraulic servo valves than the previous expressions.
基金Supported by the National Natural Science Foundation of China(No.51975164)the China Scholarship Council(No.201908230358)the Fundamental Research Fundation for Universities of Heilongjiang Province。
文摘In allusion to the problem of friction,leakage,vibration and noise existing in continuous rotary motor electro-hydraulic servo system,highly nonlinearity and uncertainties affecting the system performance,based on the transfer function of electro-hydraulic servo system,a kind of Pol-Ind friction model is proposed.The parameters of Pol-Ind friction model are identified and the accurate mathematical model of friction torque is obtained by experiment.The self-correcting wavelet neural network(WNN)controller is proposed,and Adam optimization algorithm is used to perform gradient optimization on scale factor and displacement factor in wavelet basis function,so as to improve the speed and precision of parameter optimization.Through comparative simulation analysis,it is clearly that the self-correcting WNN controller can effectively improve the frequency response and tracking accuracy of continuous rotary motor electro-hydraulic servo system.
基金the National Natural Science Foundation of China(No.51975164)the China Scholarship Council(No.201908230358)the Fundamental Research Fundation for Universities of Heilongjiang Province(No.2019-KYYWF-0205)。
文摘In order to study the influence of inlet and outlet pressure difference and triangular buffer groove on the internal leakage of continuous rotary electro-hydraulic servo motor,the flow field model of motor with and without triangular groove is established respectively.The mesh model is divided.The pressure distribution of the internal flow field under different pressure difference is analyzed by Fluent.Then,the gap leakage under different pressure difference is calculated,and the leakage curve is obtained.Finally,continuous rotary electro-hydraulic servo motor experimental system is built to conduct the internal leakage test,and the leakage under different pressure difference is measured and compared with the simulation results.The results show that the occurrence of leakage in the motor can be reduced by setting the triangular buffer groove on the flow plate,the simulation and experimental results are consistent.It can be concluded that the larger the pressure difference between the inlet and the outlet of the motor,the larger the gap leakage.The research lays foundation for the application of continuous rotary electro-hydraulic servo motor.
基金The MKE(The Ministry of Knowledge Economy),Korea,under the Human Resources Development Program for Robotics Support Program supervised by the NIPA(National IT Industry Promotion Agency)(NIPA-2012-H1502-12-1002)The MKE,Korea,under the ITRC(Infor mation Technology Research Center)Support Program supervised by the NIPA(NI-PA-2012-H0301-12-2006)
文摘This paper proposes a method that rotation angle of servo motor and distance values of ultrasonic sensor are used for tracking an object in real-time while the robot keeps regular distance.Object detection distance widens by using ultrasonic sensors and object recognition,and movement of robot is controlled by angle of servo motor and distance of ultrasonic sensors.Not adopting the existing tracking methods:camera,laser-infrared(LRF)and many ultrasonic sensors,the proposed method proves that it is possible to track object using ultrasonic sensor and servo motor.Trajectory of robot is represented and analysed according to movement of object in limited conditions.
文摘The time domain guideposts requirements of a pump-motor system is transfered into a series of constraints which express the robust performance upper bound and regional poles limits of the closed loop system. Then the servo system control problem is transferred into the problem of robust performance optimizing under regional poles constrains described by linear matrix inequality （LMI）. These LMIs are easy to solve through the Matlab LMI-toolbox. Simulations indicate that the controller has excellent dynamic, static and disturbance rejection performance, and the control system is robust and has perfect H2 performance to the bounded external torque disturbance.
基金Supported by the National Important and Special Project of China of the Twelfth Five-year Plan (2012ZX04001021)
文摘To change the current phenomenon of ＂Being an armchair strategist＂ in the research of a stepping motor, the virtual simu- lation system of stepping motor was developed using virtual reality technique. The basic principle of stepping motor was expounded. The development strategy of the simulation software is introduced. Some key problems and their solutions, including coordinate transformation of rotor and order of on-off electricity for stator, were put forward in system development. Finally, there are three virtual simulation examples of the on-off electricity way in this paper. This work provides a valuable auxiliary tool for the study of the stepping motor.
