A new hybrid control scheme is presented with a robust multiple model fusion control（RMMFC） law for a UH-60 helicopter and an active disturbance rejection control（ADRC） controller for its engines.This scheme is a ...A new hybrid control scheme is presented with a robust multiple model fusion control（RMMFC） law for a UH-60 helicopter and an active disturbance rejection control（ADRC） controller for its engines.This scheme is a control design method with every subsystem designed separately but fully considering the couplings between them.With three subspaces with respect to forward flight velocity,a RMMFC is proposed to devise a four-loop reference signal tracing control for the helicopter,which escapes the closed-loop system from unstable state due to the extreme complexity of this integrated nonlinear system.The engines are controlled by the proposed ADRC decoupling controller,which fully takes advantage of a good compensation ability for unmodeled dynamics and extra disturbances,so as to compensate torque disturbance in power turbine speed loop.By simulating a forward acceleration flight task,the RMMFC for the helicopter is validated.It is apparent that the integrated helicopter and engine system（IHES） has much better dynamic performance under the new control scheme.Especially in the switching process,the large transient is significantly weakened,and smooth transition among candidate controllers is achieved.Over the entire simulation task,the droop of power turbine speed with the proposed ADRC controller is significantly slighter than with the conventional PID controller,and the response time of the former is much faster than the latter.By simulating a rapid climb and descent flight task,the results also show the feasibility for the application of the proposed multiple model fusion control.Although there is aggressive power demand in this maneuver,the droop of power turbine speed with an ADRC controller is smaller than using a PID controller.The control performance for helicopter and engine is enhanced by adopting this hybrid control scheme,and simulation results in other envelope state give proofs of robustness for this new scheme.展开更多
Web service applications are increasing tremendously in support of high-level businesses.There must be a need of better server load balancing mechanism for improving the performance of web services in business.Though ...Web service applications are increasing tremendously in support of high-level businesses.There must be a need of better server load balancing mechanism for improving the performance of web services in business.Though many load balancing methods exist,there is still a need for sophisticated load bal-ancing mechanism for not letting the clients to get frustrated.In this work,the ser-ver with minimum response time and the server having less traffic volume were selected for the aimed server to process the forthcoming requests.The Servers are probed with adaptive control of time with two thresholds L and U to indicate the status of server load in terms of response time difference as low,medium and high load by the load balancing application.Fetching the real time responses of entire servers in the server farm is a key component of this intelligent Load balancing system.Many Load Balancing schemes are based on the graded thresholds,because the exact information about the networkflux is difficult to obtain.Using two thresholds L and U,it is possible to indicate the load on particular server as low,medium or high depending on the Maximum response time difference of the servers present in the server farm which is below L,between L and U or above U respectively.However,the existing works of load balancing in the server farm incorporatefixed time to measure real time response time,which in general are not optimal for all traffic conditions.Therefore,an algorithm based on Propor-tional Integration and Derivative neural network controller was designed with two thresholds for tuning the timing to probe the server for near optimal perfor-mance.The emulation results has shown a significant gain in the performance by tuning the threshold time.In addition to that,tuning algorithm is implemented in conjunction with Load Balancing scheme which does not tune thefixed time slots.展开更多
The functional range of actiyator of diesel engine used in bulldozer was limited when the load of bulldozer was heavy, inconstancy and in the condition of fine working. For this reason the engine rotary speed controll...The functional range of actiyator of diesel engine used in bulldozer was limited when the load of bulldozer was heavy, inconstancy and in the condition of fine working. For this reason the engine rotary speed controlling system consisted of digital controller and proportional actuator was applied; to meet the needs of high controlling precision requirement the online system identification for the engine rotary speed controlling system was carry out;Based on the result of system identification the control parameter PID was optimized. Test study proved that this engine speed controlling method have an excellent speed controlling performance.展开更多
A variable nozzle turbocharger （VNT） was applied to a 2.2-liter L4 natural gas engine,and a VNT control system was designed to operate it.Based on VNT matching test results,a VNT control strategy was studied,in whic...A variable nozzle turbocharger （VNT） was applied to a 2.2-liter L4 natural gas engine,and a VNT control system was designed to operate it.Based on VNT matching test results,a VNT control strategy was studied,in which VNT adjustment is carried out through pre-calibrated VNT handling rod position,combined with a closed-loop target boost pressure feedback using proportional-integral-derivative（PID） algorithm.Experimental results showed that the VNT control system presented in this thesis can lead to optimized performance of VNT,increase engine volumetric efficiency over a wide speed range,improve engine dynamic characteristics and upgrade economic performance.展开更多
In this paper;the dynamic characteristics of a semi-active magnetorheological fluid(MRF)engine mount are studied.To do so,the performance of the MRF engine mount is experimentally examined in higher frequencies(50~170...In this paper;the dynamic characteristics of a semi-active magnetorheological fluid(MRF)engine mount are studied.To do so,the performance of the MRF engine mount is experimentally examined in higher frequencies(50~170 Hz)and the various amplitudes(0.01~0.2 mm).In such an examination,an MRF engine mount along with its magnetically biased is fabricated and successfully measured.In addition,the natural frequencies of the system are obtained by standard hammer modal test.For modelling the behavior of the system,a mass-spring-damper model with tuned PID coefficients based on Pessen integral of absolute error method is used.The parameters of such a model including mass,damping ratio,and stiffness are identified with the help of experimental modal tests and the recursive least square method(RLS).It is shown that using PID controller leads to reducing the vibration transmissibility in the resonance frequency(=93.45 Hz)with respect to the typical passive engine mount by a factor of 58%.The average of the vibration transmissibility decreasing is also 43%within frequency bandwidth(50~170 Hz).展开更多
To deal with the rate-dependent hysteresis presented in a magnetostrictive actuator, a new method of modeling and control is proposed. The relationship between inputs and outputs of the actuator is approximately descr...To deal with the rate-dependent hysteresis presented in a magnetostrictive actuator, a new method of modeling and control is proposed. The relationship between inputs and outputs of the actuator is approximately described by a dynamic differential equation with two rate-dependent coefficients, each expressed as a polynomial of frequency. For a given frequency, the coefficients will be able to be estimated by approximating the experimental data of the outputs of the magnetostrictive actuator. Based on this model, a quasi-PID controller is designed. In the space of the coefficients and frequency, the stable domain of closed loop system with hysteresis is analyzed. The numerical simulation and experiments have born witness to the feasibility of the proposed new method.展开更多
为解决以往PID控制器对非线性、时变的推床位置自动控制(Automatic Position Control,APC)系统控制效果不理想,无法满足钛合金轧制精度标准的问题,提出将PID位置调节器改进为模糊PID位置调节器的方案。同时为解决模糊控制中量化因子和...为解决以往PID控制器对非线性、时变的推床位置自动控制(Automatic Position Control,APC)系统控制效果不理想,无法满足钛合金轧制精度标准的问题,提出将PID位置调节器改进为模糊PID位置调节器的方案。同时为解决模糊控制中量化因子和比例因子取值过度依赖专家经验的问题,引入粒子群算法寻找参数最优值。针对粒子群优化模糊PID算法难以在工程中应用这一现状,提出一种解决方法,并在实验平台中采用该方法对改进后的推床APC系统进行实验验证,证明该方法实际可行。仿真与实验表明:改进后的推床APC系统具有响应速度快、几乎无超调等优点,能够更好地满足钛合金轧制的精度要求。展开更多
The technology of knowledge base remote design of the smart fuzzy controllers with the application of the"Soft/quantum computing optimizer"toolkit software developed.The possibility of the transmission...The technology of knowledge base remote design of the smart fuzzy controllers with the application of the"Soft/quantum computing optimizer"toolkit software developed.The possibility of the transmission and communication the knowledge base using remote connection to the control object considered.Transmission and communication of the fuzzy controller’s knowledge bases implemented through the remote connection with the control object in the online mode apply the Bluetooth or WiFi technologies.Remote transmission of knowledge bases allows designing many different built-in intelligent controllers to implement a variety of control strategies under conditions of uncertainty and risk.As examples,two different models of robots described(mobile manipulator and(“cart-pole”system)inverted pendulum).A comparison of the control quality between fuzzy controllers and quantum fuzzy controller in various control modes is presented.The ability to connect and work with a physical model of control object without using than mathematical model demonstrated.The implemented technology of knowledge base design sharing in a swarm of intelligent robots with quantum controllers.It allows to achieve the goal of control and to gain additional knowledge by creating a new quantum hidden information source based on the synergetic effect of combining knowledge.Development and implementation of intelligent robust controller’s prototype for the intelligent quantum control system of mega-science project NICA(at the first stage for the cooling system of superconducted magnets)is discussed.The results of the experiments demonstrate the possibility of the ensured achievement of the control goal of a group of robots using soft/quantum computing technologies in the design of knowledge bases of smart fuzzy controllers in quantum intelligent control systems.The developed software toolkit allows to design and setup complex ill-defined and weakly formalized technical systems on line.展开更多
基金Funding of Jiangsu Innovation Program for Graduate Education (CXLX11_0213)Aeronautical Science Foundation of China (2010ZB52011)
文摘A new hybrid control scheme is presented with a robust multiple model fusion control（RMMFC） law for a UH-60 helicopter and an active disturbance rejection control（ADRC） controller for its engines.This scheme is a control design method with every subsystem designed separately but fully considering the couplings between them.With three subspaces with respect to forward flight velocity,a RMMFC is proposed to devise a four-loop reference signal tracing control for the helicopter,which escapes the closed-loop system from unstable state due to the extreme complexity of this integrated nonlinear system.The engines are controlled by the proposed ADRC decoupling controller,which fully takes advantage of a good compensation ability for unmodeled dynamics and extra disturbances,so as to compensate torque disturbance in power turbine speed loop.By simulating a forward acceleration flight task,the RMMFC for the helicopter is validated.It is apparent that the integrated helicopter and engine system（IHES） has much better dynamic performance under the new control scheme.Especially in the switching process,the large transient is significantly weakened,and smooth transition among candidate controllers is achieved.Over the entire simulation task,the droop of power turbine speed with the proposed ADRC controller is significantly slighter than with the conventional PID controller,and the response time of the former is much faster than the latter.By simulating a rapid climb and descent flight task,the results also show the feasibility for the application of the proposed multiple model fusion control.Although there is aggressive power demand in this maneuver,the droop of power turbine speed with an ADRC controller is smaller than using a PID controller.The control performance for helicopter and engine is enhanced by adopting this hybrid control scheme,and simulation results in other envelope state give proofs of robustness for this new scheme.
文摘Web service applications are increasing tremendously in support of high-level businesses.There must be a need of better server load balancing mechanism for improving the performance of web services in business.Though many load balancing methods exist,there is still a need for sophisticated load bal-ancing mechanism for not letting the clients to get frustrated.In this work,the ser-ver with minimum response time and the server having less traffic volume were selected for the aimed server to process the forthcoming requests.The Servers are probed with adaptive control of time with two thresholds L and U to indicate the status of server load in terms of response time difference as low,medium and high load by the load balancing application.Fetching the real time responses of entire servers in the server farm is a key component of this intelligent Load balancing system.Many Load Balancing schemes are based on the graded thresholds,because the exact information about the networkflux is difficult to obtain.Using two thresholds L and U,it is possible to indicate the load on particular server as low,medium or high depending on the Maximum response time difference of the servers present in the server farm which is below L,between L and U or above U respectively.However,the existing works of load balancing in the server farm incorporatefixed time to measure real time response time,which in general are not optimal for all traffic conditions.Therefore,an algorithm based on Propor-tional Integration and Derivative neural network controller was designed with two thresholds for tuning the timing to probe the server for near optimal perfor-mance.The emulation results has shown a significant gain in the performance by tuning the threshold time.In addition to that,tuning algorithm is implemented in conjunction with Load Balancing scheme which does not tune thefixed time slots.
文摘The functional range of actiyator of diesel engine used in bulldozer was limited when the load of bulldozer was heavy, inconstancy and in the condition of fine working. For this reason the engine rotary speed controlling system consisted of digital controller and proportional actuator was applied; to meet the needs of high controlling precision requirement the online system identification for the engine rotary speed controlling system was carry out;Based on the result of system identification the control parameter PID was optimized. Test study proved that this engine speed controlling method have an excellent speed controlling performance.
基金Sponsored by the Ministerial Advanced Research Foundation (C2002AA002)
文摘A variable nozzle turbocharger （VNT） was applied to a 2.2-liter L4 natural gas engine,and a VNT control system was designed to operate it.Based on VNT matching test results,a VNT control strategy was studied,in which VNT adjustment is carried out through pre-calibrated VNT handling rod position,combined with a closed-loop target boost pressure feedback using proportional-integral-derivative（PID） algorithm.Experimental results showed that the VNT control system presented in this thesis can lead to optimized performance of VNT,increase engine volumetric efficiency over a wide speed range,improve engine dynamic characteristics and upgrade economic performance.
文摘In this paper;the dynamic characteristics of a semi-active magnetorheological fluid(MRF)engine mount are studied.To do so,the performance of the MRF engine mount is experimentally examined in higher frequencies(50~170 Hz)and the various amplitudes(0.01~0.2 mm).In such an examination,an MRF engine mount along with its magnetically biased is fabricated and successfully measured.In addition,the natural frequencies of the system are obtained by standard hammer modal test.For modelling the behavior of the system,a mass-spring-damper model with tuned PID coefficients based on Pessen integral of absolute error method is used.The parameters of such a model including mass,damping ratio,and stiffness are identified with the help of experimental modal tests and the recursive least square method(RLS).It is shown that using PID controller leads to reducing the vibration transmissibility in the resonance frequency(=93.45 Hz)with respect to the typical passive engine mount by a factor of 58%.The average of the vibration transmissibility decreasing is also 43%within frequency bandwidth(50~170 Hz).
基金National Natural Science Foundation of China (60534020)National Key Project for Basic Research of China (G2002cb312205-02)Key Subject Foundation of Beijing (XK100060526)
文摘To deal with the rate-dependent hysteresis presented in a magnetostrictive actuator, a new method of modeling and control is proposed. The relationship between inputs and outputs of the actuator is approximately described by a dynamic differential equation with two rate-dependent coefficients, each expressed as a polynomial of frequency. For a given frequency, the coefficients will be able to be estimated by approximating the experimental data of the outputs of the magnetostrictive actuator. Based on this model, a quasi-PID controller is designed. In the space of the coefficients and frequency, the stable domain of closed loop system with hysteresis is analyzed. The numerical simulation and experiments have born witness to the feasibility of the proposed new method.
文摘为解决以往PID控制器对非线性、时变的推床位置自动控制(Automatic Position Control,APC)系统控制效果不理想,无法满足钛合金轧制精度标准的问题,提出将PID位置调节器改进为模糊PID位置调节器的方案。同时为解决模糊控制中量化因子和比例因子取值过度依赖专家经验的问题,引入粒子群算法寻找参数最优值。针对粒子群优化模糊PID算法难以在工程中应用这一现状,提出一种解决方法,并在实验平台中采用该方法对改进后的推床APC系统进行实验验证,证明该方法实际可行。仿真与实验表明:改进后的推床APC系统具有响应速度快、几乎无超调等优点,能够更好地满足钛合金轧制的精度要求。
文摘The technology of knowledge base remote design of the smart fuzzy controllers with the application of the"Soft/quantum computing optimizer"toolkit software developed.The possibility of the transmission and communication the knowledge base using remote connection to the control object considered.Transmission and communication of the fuzzy controller’s knowledge bases implemented through the remote connection with the control object in the online mode apply the Bluetooth or WiFi technologies.Remote transmission of knowledge bases allows designing many different built-in intelligent controllers to implement a variety of control strategies under conditions of uncertainty and risk.As examples,two different models of robots described(mobile manipulator and(“cart-pole”system)inverted pendulum).A comparison of the control quality between fuzzy controllers and quantum fuzzy controller in various control modes is presented.The ability to connect and work with a physical model of control object without using than mathematical model demonstrated.The implemented technology of knowledge base design sharing in a swarm of intelligent robots with quantum controllers.It allows to achieve the goal of control and to gain additional knowledge by creating a new quantum hidden information source based on the synergetic effect of combining knowledge.Development and implementation of intelligent robust controller’s prototype for the intelligent quantum control system of mega-science project NICA(at the first stage for the cooling system of superconducted magnets)is discussed.The results of the experiments demonstrate the possibility of the ensured achievement of the control goal of a group of robots using soft/quantum computing technologies in the design of knowledge bases of smart fuzzy controllers in quantum intelligent control systems.The developed software toolkit allows to design and setup complex ill-defined and weakly formalized technical systems on line.
