Permanent magnet synchronous motor based electro-mechanical actuation servo drives have widespread applications in the aviation field,such as unmanned aerial vehicle electric servos,electric cabin doors,and mechanical...Permanent magnet synchronous motor based electro-mechanical actuation servo drives have widespread applications in the aviation field,such as unmanned aerial vehicle electric servos,electric cabin doors,and mechanical arms.The performance of the servo drive,which encompasses the response to the torque,efficiency,control bandwidth and the steady-state positioning accuracy,significantly influences the performance of the aviation actuation.Consequently,enhancing the control bandwidth and refining the positioning accuracy of aviation electro-mechanical actuation servo drives have emerged as a focal point of research.This paper investigates the multi-source disturbances present in aviation electro-mechanical actuation servo systems and summarizes recent research on high-performance servo control methods based on active disturbance rejection control(ADRC).We present a comprehensive overview of the research status pertaining to servo control architecture,strategies for suppressing disturbances in the current loop,and ADRC-based strategies for the position loop.We delineate the research challenges and difficulties encountered by aviation electro-mechanical actuation servo drive control technology.展开更多
This article investigates the anti-disturbance and stabilization problems for the nonlinear uncertain permanent magnet synchronous motor(PMSM)with stator voltage saturation and unknown load.A smooth switching mechanis...This article investigates the anti-disturbance and stabilization problems for the nonlinear uncertain permanent magnet synchronous motor(PMSM)with stator voltage saturation and unknown load.A smooth switching mechanism is presented to structure the adaptive integral terminal sliding mode control(SMC)strategy.The control design consists of compensation control and nominal control,which improves the rapidity and accuracy of trajectory tracking.The smooth saturation model based on the error function is applied to approximate the voltage saturation phenomenon.Additionally,to deal with the adverse effects of various unknown disturbances,including model parameter uncertainties and unknown external load disturbances,an improved disturbance observer(DO)is proposed.This observer effectively suppresses the fluctuations caused by fixed gain during the starting period of the system.Finally,the experimental results under different conditions show that the proposed strategy has good tracking and disturbance suppression performances.展开更多
A new suspension gravity compensation system has been developed to alleviate the gravity effects on a two-dimensional(2D)deployable mechanism for ground verification.Considering the rigid-flexible coupling of both the...A new suspension gravity compensation system has been developed to alleviate the gravity effects on a two-dimensional(2D)deployable mechanism for ground verification.Considering the rigid-flexible coupling of both the rotating servo and the suspension system,a multi-body dynamic model simulating their integration is established using Lagrange’s equation.To mitigate instantaneous impact forces due to significant non-plumb effects from passive following in the horizontal direction,an elastic element is added in series with the rope in the vertical suspension system.The dynamic response of this elastic element relative to the rotating servo system is analyzed by the ADAMS software.Simulation results show that the compensating error decreases significantly from 45%to 0.31%when incorporating elastic elements compared to scenarios without such elements.Additionally,low-stiffness elastic elements demonstrate a higher compensating error than high-stiffness ones.A spring with a stiffness coefficient of 6 N/mm is selected in the experiment,ensuring that compensating error meets the design specification of 5%.展开更多
Computer-aided surgical navigation technology helps and guides doctors to complete the operation smoothly,which simulates the whole surgical environment with computer technology,and then visualizes the whole operation...Computer-aided surgical navigation technology helps and guides doctors to complete the operation smoothly,which simulates the whole surgical environment with computer technology,and then visualizes the whole operation link in three dimensions.At present,common image-guided surgical techniques such as computed tomography(CT)and X-ray imaging(X-ray)will cause radiation damage to the human body during the imaging process.To address this,we propose a novel Extended Kalman filter-based model that tracks the puncture needle-point using an ultrasound probe.To address the limitations of Kalman filteringmethods based on position and velocity,our method of Kalman filtering uses the position and relative velocity of the puncture needle-point instead,and the ultrasonic probe is controlled by a Proportional Integral(PI)controller in X-axis direction and Proportional Derivative(PD)controller in the Y-axis direction.The motion of the ultrasonic probe can be servo-controlled by whether the image information of the puncture needle-point can be detected by the ultrasonic image so that the ultrasonic probe can track the puncture needle-point in real time.The experiment results show that this method has better tracking performance.展开更多
This paper presents a method of multicopter intercep-tion control based on visual servo and virtual tube in a cluttered environment.The proposed hybrid heuristic function improves the efficiency of the A*algorithm.The...This paper presents a method of multicopter intercep-tion control based on visual servo and virtual tube in a cluttered environment.The proposed hybrid heuristic function improves the efficiency of the A*algorithm.The revised objective function makes the virtual tube generating curve not only smooth but also close to the path points generated by the A*algorithm.In six dif-ferent simulation scenarios,the efficiency of the modified A*algorithm is 6.2%higher than that of the traditional A*algorithm.The efficiency of path planning and virtual tube planning is veri-fied by simulations.The effectiveness of interception control is verified by a software-in-loop(SIL)simulation.展开更多
The aim of the study is to investigate the impact of the buffer groove structure on the pressure of continuous rotation electro-hydraulic servo motor.The mathematical model of the motor valve plate with triangular gro...The aim of the study is to investigate the impact of the buffer groove structure on the pressure of continuous rotation electro-hydraulic servo motor.The mathematical model of the motor valve plate with triangular groove and U-groove structure is established firstly,and the structure size of the two buffer grooves with better pressure drop effect is obtained by Matlab.Secondly,an established pressure gradient model is developed for the sealed canisters for electric motors using a combined groove structure.The bird swarm optimization algorithm is used to obtain the optimal dimensions for the combined depth and angle of the pressure groove.The flow field in the motor seal chamber is simulated and calculated by Fluent.This study compared the pressure field distributions in the motors sealing chamber using triangular and combined groove structures.It investigated the combined grooves effect on the pressure impact during the commutation of a continuously rotating electro-hydraulic servo motor.It is found that the combined groove structure has a positive impact on reducing the pressure impact.The results indicate that the combined groove structure significantly enhances the efficiency of mitigating pressure shocks when the motor switches between high-and low-pressure chambers.展开更多
Hydraulic technology has the outstanding advantages of easy pressure compensation and high power density.It is an indispensable part of subsea equipment,such as deep-sea operations and submersible propulsion.There are...Hydraulic technology has the outstanding advantages of easy pressure compensation and high power density.It is an indispensable part of subsea equipment,such as deep-sea operations and submersible propulsion.There are few studies on electrohydraulic servo valves(EHSVs)in the deep sea.In this work,a novel electro-hydraulic servo rotary valve is designed,and its mathematical model is established.The analysis considers the variations in physical parameters such as temperature,ambient pressure,and oil viscosity resulting from changes in sea depth.This study focuses on the deformation of the rotary valve and the consequent alterations in leakage and friction torque.The findings indicate that at a depth of 12000 m,the fit clearance between the valve spool and the valve sleeve is 0.00413 mm,representing a 17%reduction compared with the clearance in a land environment.Then,the response of the rotary valve to depth is analyzed.The results indicate that the bandwidth of the rotary valve decreases with increasing depth.This study provides a reference for the use of the EHSV in the deep sea.展开更多
An enhanced least mean square(LMS)error identification algorithm integrated with Kalman filtering is proposed to resolve accuracy degradation induced by nonlinear dynamics and parameter uncertainties in continuous rot...An enhanced least mean square(LMS)error identification algorithm integrated with Kalman filtering is proposed to resolve accuracy degradation induced by nonlinear dynamics and parameter uncertainties in continuous rotary electro-hydraulic servo systems.This enhancement accelerates convergence and improves accuracy compared with traditional LMS.A fifth-order identification mod-el is developed based on valve-controlled hydraulic motors,with parameters identified using Kalman filter state estimation and gradient smoothing.The results indicate that the improved LMS effectively enhances parameter identification.An advanced disturbance rejection controller(ADRC)is de-signed,and its performance is compared with an optimal proportional integral derivative(PID)con-troller through Simulink simulations.The results show that the ADRC fulfills the control specifications and expands the system’s operational bandwidth.展开更多
A tracking stability control problem for the vertical electric stabilization system of moving tank based on adaptive robust servo control is addressed.This paper mainly focuses on two types of possibly fast timevaryin...A tracking stability control problem for the vertical electric stabilization system of moving tank based on adaptive robust servo control is addressed.This paper mainly focuses on two types of possibly fast timevarying but bounded uncertainty within the vertical electric stabilization system:model parameter uncertainty and uncertain nonlinearity.First,the vertical electric stabilization system is constructed as an uncertain nonlinear dynamic system that can reflect the practical mechanics transfer process of the system.Second,the dynamical equation in the form of state space is established by designing the angular tracking error.Third,the comprehensive parameter of system uncertainty is designed to estimate the most conservative effects of uncertainty.Finally,an adaptive robust servo control which can effectively handle the combined effects of complex nonlinearity and uncertainty is proposed.The feasibility of the proposed control strategy under the practical physical condition is validated through the tests on the experimental platform.This paper pioneers the introduction of the internal nonlinearity and uncertainty of the vertical electric stabilization system into the settlement of the tracking stability control problem,and validates the advanced servo control strategy through experiment for the first time.展开更多
In this paper,a visual servoing approach is developed to capture the docking rings of tumbling non-cooperative satellites with a space manipulator.The primary challenge addressed is the potential for the docking ring ...In this paper,a visual servoing approach is developed to capture the docking rings of tumbling non-cooperative satellites with a space manipulator.The primary challenge addressed is the potential for the docking ring to leave the monocular camera’s field-of-view as the manipulator approaches the target,due to the ring’s large size.To solve this issue,a two-phase visual servoing scheme combining a monocular camera and a three-line structured light vision system is proposed.In an effort to augment the success rate and safety of capture operations,several constraints are formulated,encompassing manipulator’s kinematics,monocular camera’s field-of-view,obstacle avoidance,structured light’s breakpoints and smooth capture.Subsequently,a nonlinear model predictive controller is proposed to manage these constraints in real-time and regulate the system.System models are established based on image moments and pose for each phase,selecting these features as visual feedback to simplify the formulation of servo constraints and avoid the complex circle-based pose measurement.Furthermore,to ensure unbiased predictions,the model disturbances arising from the imprecise estimation of target motion parameter are observed using an extended Kalman filter,which are then incorporated into the predictive control framework.The simulation results demonstrate the effectiveness of this scheme.展开更多
Vibrations or dither's are features of the PWM servo control system in their steady outputs. On the grounds of analyses and experiments of a PWM pneumatic servo control system, the paper puts forward four varietie...Vibrations or dither's are features of the PWM servo control system in their steady outputs. On the grounds of analyses and experiments of a PWM pneumatic servo control system, the paper puts forward four varieties of PWM modulation methods, and concludes on the relationship between dithers and the different methods, and then discusses the influence of friction to the dithers. Results from experiments regarding the dynamic and static responses on the given system support the theories presented.展开更多
The 30 kW high-power electric servo system used in the solid booster of the Long March 6 A(LM-6 A)launch vehicle is introduced,and the function,composition of the system as well as its constituent equipments are detai...The 30 kW high-power electric servo system used in the solid booster of the Long March 6 A(LM-6 A)launch vehicle is introduced,and the function,composition of the system as well as its constituent equipments are detailed.To solve the problem of out-of-tolerance in the system dynamic characteristics,an advanced correction network algorithm architecture and double notch filter were designed.Experimental verification was conducted to prove that the dynamic characteristics requirement under multiple operating conditions could be met.展开更多
In light of the high nonlinearity of LuGre friction model, a novel method based on ant colony algorithm(ACA) for identifying the friction parameters of flight simulation servo system is proposed. ACA is a parallelized...In light of the high nonlinearity of LuGre friction model, a novel method based on ant colony algorithm(ACA) for identifying the friction parameters of flight simulation servo system is proposed. ACA is a parallelized bionic optimization algorithm inspired from the behavior of real ants, and a kind of positive feedback mechanism is adopted in ACA. On the basis of brief introduction of LuGre friction model, a method for identifying the static LuGre friction parameters and the dynamic LuGre friction parameters using ACA is derived. Finally, this new friction parameter identification scheme is applied to a electric-driven flight simulation servo system with high precision. Simulation and application results verify the feasibility and the effectiveness of the scheme. It provides a new way to identify the friction parameters of LuGre model.展开更多
Aim To eliminate the influences of backlash nonlinear characteristics generally existing in servo systems, a nonlinear compensation method using backpropagation neural networks(BPNN) is presented. Methods Based on s...Aim To eliminate the influences of backlash nonlinear characteristics generally existing in servo systems, a nonlinear compensation method using backpropagation neural networks(BPNN) is presented. Methods Based on some weapon tracking servo system, a three layer BPNN was used to off line identify the backlash characteristics, then a nonlinear compensator was designed according to the identification results. Results The simulation results show that the method can effectively get rid of the sustained oscillation(limit cycle) of the system caused by the backlash characteristics, and can improve the system accuracy. Conclusion The method is effective on sloving the problems produced by the backlash characteristics in servo systems, and it can be easily accomplished in engineering.展开更多
In an actual control system, it is often difficult to find out where the faults are if only based on the outside fault phenomena, acquired frequently from a fault system. So the fault diagnosis by outside fault phenom...In an actual control system, it is often difficult to find out where the faults are if only based on the outside fault phenomena, acquired frequently from a fault system. So the fault diagnosis by outside fault phenomena is considered. Based on the theory of fuzzy recognition and fault diagnosis, this method only depends on experience and statistical data to set up fuzzy query relationship between the outside phenomena (fault characters) and the fault sources (fault patterns). From this relationship the most probable fault sources can be obtained, to attain the goal of quick diagnosis. Based on the above approach, the standard fuzzy relationship matrix is stored in the computer as a system database. And experiment data are given to show the fault diagnosis results. The important parameters can be on line sampled and analyzed, and when faults occur, faults can be found, the alarm is given and the controller output is regulated.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52177059 and 52407064).
文摘Permanent magnet synchronous motor based electro-mechanical actuation servo drives have widespread applications in the aviation field,such as unmanned aerial vehicle electric servos,electric cabin doors,and mechanical arms.The performance of the servo drive,which encompasses the response to the torque,efficiency,control bandwidth and the steady-state positioning accuracy,significantly influences the performance of the aviation actuation.Consequently,enhancing the control bandwidth and refining the positioning accuracy of aviation electro-mechanical actuation servo drives have emerged as a focal point of research.This paper investigates the multi-source disturbances present in aviation electro-mechanical actuation servo systems and summarizes recent research on high-performance servo control methods based on active disturbance rejection control(ADRC).We present a comprehensive overview of the research status pertaining to servo control architecture,strategies for suppressing disturbances in the current loop,and ADRC-based strategies for the position loop.We delineate the research challenges and difficulties encountered by aviation electro-mechanical actuation servo drive control technology.
基金supported by the National Natural Science Foundation under Grant 62273189the Shandong Province Natural Science Foundation under Grant ZR2021MF005Systems Science Plus Joint Research Program of Qingdao University under Grant XT2024201 of China supporting this research work.
文摘This article investigates the anti-disturbance and stabilization problems for the nonlinear uncertain permanent magnet synchronous motor(PMSM)with stator voltage saturation and unknown load.A smooth switching mechanism is presented to structure the adaptive integral terminal sliding mode control(SMC)strategy.The control design consists of compensation control and nominal control,which improves the rapidity and accuracy of trajectory tracking.The smooth saturation model based on the error function is applied to approximate the voltage saturation phenomenon.Additionally,to deal with the adverse effects of various unknown disturbances,including model parameter uncertainties and unknown external load disturbances,an improved disturbance observer(DO)is proposed.This observer effectively suppresses the fluctuations caused by fixed gain during the starting period of the system.Finally,the experimental results under different conditions show that the proposed strategy has good tracking and disturbance suppression performances.
文摘A new suspension gravity compensation system has been developed to alleviate the gravity effects on a two-dimensional(2D)deployable mechanism for ground verification.Considering the rigid-flexible coupling of both the rotating servo and the suspension system,a multi-body dynamic model simulating their integration is established using Lagrange’s equation.To mitigate instantaneous impact forces due to significant non-plumb effects from passive following in the horizontal direction,an elastic element is added in series with the rope in the vertical suspension system.The dynamic response of this elastic element relative to the rotating servo system is analyzed by the ADAMS software.Simulation results show that the compensating error decreases significantly from 45%to 0.31%when incorporating elastic elements compared to scenarios without such elements.Additionally,low-stiffness elastic elements demonstrate a higher compensating error than high-stiffness ones.A spring with a stiffness coefficient of 6 N/mm is selected in the experiment,ensuring that compensating error meets the design specification of 5%.
基金supported by the Sichuan Science and Technology Program(2023YFSY0026,2023YFH0004).
文摘Computer-aided surgical navigation technology helps and guides doctors to complete the operation smoothly,which simulates the whole surgical environment with computer technology,and then visualizes the whole operation link in three dimensions.At present,common image-guided surgical techniques such as computed tomography(CT)and X-ray imaging(X-ray)will cause radiation damage to the human body during the imaging process.To address this,we propose a novel Extended Kalman filter-based model that tracks the puncture needle-point using an ultrasound probe.To address the limitations of Kalman filteringmethods based on position and velocity,our method of Kalman filtering uses the position and relative velocity of the puncture needle-point instead,and the ultrasonic probe is controlled by a Proportional Integral(PI)controller in X-axis direction and Proportional Derivative(PD)controller in the Y-axis direction.The motion of the ultrasonic probe can be servo-controlled by whether the image information of the puncture needle-point can be detected by the ultrasonic image so that the ultrasonic probe can track the puncture needle-point in real time.The experiment results show that this method has better tracking performance.
基金supported by the National Natural Science Foundation of China(62303350).
文摘This paper presents a method of multicopter intercep-tion control based on visual servo and virtual tube in a cluttered environment.The proposed hybrid heuristic function improves the efficiency of the A*algorithm.The revised objective function makes the virtual tube generating curve not only smooth but also close to the path points generated by the A*algorithm.In six dif-ferent simulation scenarios,the efficiency of the modified A*algorithm is 6.2%higher than that of the traditional A*algorithm.The efficiency of path planning and virtual tube planning is veri-fied by simulations.The effectiveness of interception control is verified by a software-in-loop(SIL)simulation.
基金Supported by the National Natural Science Foundation of China(No.52375037)the Masters Innovation Project of Beijing University of Civil Engineering and Architecture(No.PG2024142)+1 种基金the Outstanding Youth of Pyramid Talent Training Project of Beijing University of Civil Engineering and Architecture(No.GDRC20220801)the Breeding Program Funding of Beijing University of Civil Engineering and Architecture(No.X24026).
文摘The aim of the study is to investigate the impact of the buffer groove structure on the pressure of continuous rotation electro-hydraulic servo motor.The mathematical model of the motor valve plate with triangular groove and U-groove structure is established firstly,and the structure size of the two buffer grooves with better pressure drop effect is obtained by Matlab.Secondly,an established pressure gradient model is developed for the sealed canisters for electric motors using a combined groove structure.The bird swarm optimization algorithm is used to obtain the optimal dimensions for the combined depth and angle of the pressure groove.The flow field in the motor seal chamber is simulated and calculated by Fluent.This study compared the pressure field distributions in the motors sealing chamber using triangular and combined groove structures.It investigated the combined grooves effect on the pressure impact during the commutation of a continuously rotating electro-hydraulic servo motor.It is found that the combined groove structure has a positive impact on reducing the pressure impact.The results indicate that the combined groove structure significantly enhances the efficiency of mitigating pressure shocks when the motor switches between high-and low-pressure chambers.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFC2805703)the Major Training Program of University Research and Innovation Platform of Gansu Provincial Department of Education(Grant No.2024CXPT-09).
文摘Hydraulic technology has the outstanding advantages of easy pressure compensation and high power density.It is an indispensable part of subsea equipment,such as deep-sea operations and submersible propulsion.There are few studies on electrohydraulic servo valves(EHSVs)in the deep sea.In this work,a novel electro-hydraulic servo rotary valve is designed,and its mathematical model is established.The analysis considers the variations in physical parameters such as temperature,ambient pressure,and oil viscosity resulting from changes in sea depth.This study focuses on the deformation of the rotary valve and the consequent alterations in leakage and friction torque.The findings indicate that at a depth of 12000 m,the fit clearance between the valve spool and the valve sleeve is 0.00413 mm,representing a 17%reduction compared with the clearance in a land environment.Then,the response of the rotary valve to depth is analyzed.The results indicate that the bandwidth of the rotary valve decreases with increasing depth.This study provides a reference for the use of the EHSV in the deep sea.
基金Supported by the National Natural Science Foundation of China(No.52375037)the Outstanding Youth of Pyramid Talent Training Project of Beijing University of Civil Engineering and Architecture(No.GDRC 20220801)+1 种基金the Graduate Innovation Fund Project of Beijing University of Civil Engineering and Architecture(No.PG2025160)the Special Fund for Cultivation Projects of Beijing University of Civil Engineering and Architecture(No.X24026).
文摘An enhanced least mean square(LMS)error identification algorithm integrated with Kalman filtering is proposed to resolve accuracy degradation induced by nonlinear dynamics and parameter uncertainties in continuous rotary electro-hydraulic servo systems.This enhancement accelerates convergence and improves accuracy compared with traditional LMS.A fifth-order identification mod-el is developed based on valve-controlled hydraulic motors,with parameters identified using Kalman filter state estimation and gradient smoothing.The results indicate that the improved LMS effectively enhances parameter identification.An advanced disturbance rejection controller(ADRC)is de-signed,and its performance is compared with an optimal proportional integral derivative(PID)con-troller through Simulink simulations.The results show that the ADRC fulfills the control specifications and expands the system’s operational bandwidth.
基金supported in part by the Nation Natural Science Foundation of China under Grant No.52175099China Postdoctoral Science Foundation under Grant No.2020M671494Jiangsu Planned Projects for Postdoctoral Research Funds under Grant No.2020Z179。
文摘A tracking stability control problem for the vertical electric stabilization system of moving tank based on adaptive robust servo control is addressed.This paper mainly focuses on two types of possibly fast timevarying but bounded uncertainty within the vertical electric stabilization system:model parameter uncertainty and uncertain nonlinearity.First,the vertical electric stabilization system is constructed as an uncertain nonlinear dynamic system that can reflect the practical mechanics transfer process of the system.Second,the dynamical equation in the form of state space is established by designing the angular tracking error.Third,the comprehensive parameter of system uncertainty is designed to estimate the most conservative effects of uncertainty.Finally,an adaptive robust servo control which can effectively handle the combined effects of complex nonlinearity and uncertainty is proposed.The feasibility of the proposed control strategy under the practical physical condition is validated through the tests on the experimental platform.This paper pioneers the introduction of the internal nonlinearity and uncertainty of the vertical electric stabilization system into the settlement of the tracking stability control problem,and validates the advanced servo control strategy through experiment for the first time.
基金supported by the China Postdoctoral Science Foundation(No.2022M710956).
文摘In this paper,a visual servoing approach is developed to capture the docking rings of tumbling non-cooperative satellites with a space manipulator.The primary challenge addressed is the potential for the docking ring to leave the monocular camera’s field-of-view as the manipulator approaches the target,due to the ring’s large size.To solve this issue,a two-phase visual servoing scheme combining a monocular camera and a three-line structured light vision system is proposed.In an effort to augment the success rate and safety of capture operations,several constraints are formulated,encompassing manipulator’s kinematics,monocular camera’s field-of-view,obstacle avoidance,structured light’s breakpoints and smooth capture.Subsequently,a nonlinear model predictive controller is proposed to manage these constraints in real-time and regulate the system.System models are established based on image moments and pose for each phase,selecting these features as visual feedback to simplify the formulation of servo constraints and avoid the complex circle-based pose measurement.Furthermore,to ensure unbiased predictions,the model disturbances arising from the imprecise estimation of target motion parameter are observed using an extended Kalman filter,which are then incorporated into the predictive control framework.The simulation results demonstrate the effectiveness of this scheme.
文摘Vibrations or dither's are features of the PWM servo control system in their steady outputs. On the grounds of analyses and experiments of a PWM pneumatic servo control system, the paper puts forward four varieties of PWM modulation methods, and concludes on the relationship between dithers and the different methods, and then discusses the influence of friction to the dithers. Results from experiments regarding the dynamic and static responses on the given system support the theories presented.
文摘The 30 kW high-power electric servo system used in the solid booster of the Long March 6 A(LM-6 A)launch vehicle is introduced,and the function,composition of the system as well as its constituent equipments are detailed.To solve the problem of out-of-tolerance in the system dynamic characteristics,an advanced correction network algorithm architecture and double notch filter were designed.Experimental verification was conducted to prove that the dynamic characteristics requirement under multiple operating conditions could be met.
文摘In light of the high nonlinearity of LuGre friction model, a novel method based on ant colony algorithm(ACA) for identifying the friction parameters of flight simulation servo system is proposed. ACA is a parallelized bionic optimization algorithm inspired from the behavior of real ants, and a kind of positive feedback mechanism is adopted in ACA. On the basis of brief introduction of LuGre friction model, a method for identifying the static LuGre friction parameters and the dynamic LuGre friction parameters using ACA is derived. Finally, this new friction parameter identification scheme is applied to a electric-driven flight simulation servo system with high precision. Simulation and application results verify the feasibility and the effectiveness of the scheme. It provides a new way to identify the friction parameters of LuGre model.
文摘Aim To eliminate the influences of backlash nonlinear characteristics generally existing in servo systems, a nonlinear compensation method using backpropagation neural networks(BPNN) is presented. Methods Based on some weapon tracking servo system, a three layer BPNN was used to off line identify the backlash characteristics, then a nonlinear compensator was designed according to the identification results. Results The simulation results show that the method can effectively get rid of the sustained oscillation(limit cycle) of the system caused by the backlash characteristics, and can improve the system accuracy. Conclusion The method is effective on sloving the problems produced by the backlash characteristics in servo systems, and it can be easily accomplished in engineering.
文摘In an actual control system, it is often difficult to find out where the faults are if only based on the outside fault phenomena, acquired frequently from a fault system. So the fault diagnosis by outside fault phenomena is considered. Based on the theory of fuzzy recognition and fault diagnosis, this method only depends on experience and statistical data to set up fuzzy query relationship between the outside phenomena (fault characters) and the fault sources (fault patterns). From this relationship the most probable fault sources can be obtained, to attain the goal of quick diagnosis. Based on the above approach, the standard fuzzy relationship matrix is stored in the computer as a system database. And experiment data are given to show the fault diagnosis results. The important parameters can be on line sampled and analyzed, and when faults occur, faults can be found, the alarm is given and the controller output is regulated.
