In view of the current sensors failure in electric pitch system,a variable universe fuzzy fault tolerant control method of electric pitch control system based on single current detection is proposed.When there is sing...In view of the current sensors failure in electric pitch system,a variable universe fuzzy fault tolerant control method of electric pitch control system based on single current detection is proposed.When there is single or two-current sensor fault occurs,based on the proposed method the missing current information can be reconstructed by using direct current（DC）bus current sensor and the three-phase current can be updated in time within any two adjacent sampling periods,so as to ensure stability of the closed-loop system.And then the switchover and fault tolerant control of fault current sensor would be accomplished by fault diagnosis method based on adaptive threshold judgment.For the reconstructed signal error caused by the modulation method and the main control target of electric pitch system,a variable universe fuzzy control method is used in the speed loop,which can improve the anti-disturbance ability to load variation,and the robustness of fault tolerance system.The results show that the fault tolerant control method makes the variable pitch control system still has ideal control characteristics in case of sensor failure although part of the system performance is lost,thus the correctness of the proposed method is verified.展开更多
Recent investigations have shown that with varying the amplitude of the external force, the deterministic ratchets exhibit multiple current reversals, which are undesirable in certain circumstances. To control the mul...Recent investigations have shown that with varying the amplitude of the external force, the deterministic ratchets exhibit multiple current reversals, which are undesirable in certain circumstances. To control the multiple reverse current to unidirectional current, an adaptive control law is presented inspired from the relation between multiple reversaJs current and the chaos-periodic/quasiperiodic transition of the transport velocity. The designed controller can stabilize the transport velocity of ratchets to steady state and suppress any chaos-periodic/quasiperiodic transition, namely, the stable transport in ratchets is achieved, which makes the current sign unchanged.展开更多
the system to DC voltage source as the core, AT89C52 MCU as the main controller, the output voltage to set the DC power supply through the keyboard, with a step function voltage to reality, the actual output value. Th...the system to DC voltage source as the core, AT89C52 MCU as the main controller, the output voltage to set the DC power supply through the keyboard, with a step function voltage to reality, the actual output value. This design is divided into four modules： SCM control and display module, digital to analog （D/A） conversion module, a constant voltage source module, output module. MCU control module as the core, the input signal is converted to digital quantity output; constant current source module voltage D/A conversion to analog conversion into constant pressure through a constant voltage circuit. The system has good reliability, high precision.展开更多
为使装甲车辆在运行过程中获得良好工作状态,通过在基速以下区域采用基于滑模极值搜索(Sliding Mode Extreme value Search Control,SMESC)的最大转矩电流比(Maximum Torque Per Ampere,MTPA)控制算法(SMESC-MTPA)和在基速以上区域使用...为使装甲车辆在运行过程中获得良好工作状态,通过在基速以下区域采用基于滑模极值搜索(Sliding Mode Extreme value Search Control,SMESC)的最大转矩电流比(Maximum Torque Per Ampere,MTPA)控制算法(SMESC-MTPA)和在基速以上区域使用弱磁控制算法的方式控制电传动装甲车辆轮毂电机,并考虑电流在高速段的交叉耦合效应及电机参数变化影响,在基速以上区域使用变交轴的单电流控制法进行弱磁控制,进而搭建基于MATLAB/Simulink的仿真模型,并通过仿真验证了该控制策略的正确性。展开更多
The boost type power supplies are widely used in portable consumer electronics to step up the input voltage to adapt for the high voltage applications like light-emitting diode(LED) driving and liquid crystal display(...The boost type power supplies are widely used in portable consumer electronics to step up the input voltage to adapt for the high voltage applications like light-emitting diode(LED) driving and liquid crystal display(LCD) biasing.In these applications,a regulator with small volume,fewer external components and high efficiency is highly desired.This paper proposes a projected off-and on-time boost control scheme,based on which a monolithic IC with an on-chip VDMOS with 0.2 Ω on-state resistance RDS-ON was implemented in 1.5 μm bipolar-CMOS-DMOS(BCD) process.A 12 V,0.3 A boost regulator prototype is presented as well.With projected off-time and modulated on-time in continuous conduction mode(CCM),a quasi fixed frequency,which is preferred for ripple control,is realized.With projected on-time and modulated off-time in discontinuous conduction mode(DCM),pulse frequency modulation(PFM) operation,which is beneficial to light load efficiency improvement,is achieved without extra control circuitry.Measurement results show that an efficiency of 3% higher than that of a conventional method under 0.5 W output is achieved while a step load transient response comparable to that of current mode control is maintained as well.展开更多
基金Natural Science Foundation of Gansu Province(Joint)Project(No.213244)Natural Science Foundation of Gansu Province(No.145RJZA136)Youth Science Foundation of Lanzhou Jiaotong University(No.2013040)
文摘In view of the current sensors failure in electric pitch system,a variable universe fuzzy fault tolerant control method of electric pitch control system based on single current detection is proposed.When there is single or two-current sensor fault occurs,based on the proposed method the missing current information can be reconstructed by using direct current（DC）bus current sensor and the three-phase current can be updated in time within any two adjacent sampling periods,so as to ensure stability of the closed-loop system.And then the switchover and fault tolerant control of fault current sensor would be accomplished by fault diagnosis method based on adaptive threshold judgment.For the reconstructed signal error caused by the modulation method and the main control target of electric pitch system,a variable universe fuzzy control method is used in the speed loop,which can improve the anti-disturbance ability to load variation,and the robustness of fault tolerance system.The results show that the fault tolerant control method makes the variable pitch control system still has ideal control characteristics in case of sensor failure although part of the system performance is lost,thus the correctness of the proposed method is verified.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 10862001 and 10947011the Construction of Key Laboratories in Universities of Guangxi under Grant No. 200912
文摘Recent investigations have shown that with varying the amplitude of the external force, the deterministic ratchets exhibit multiple current reversals, which are undesirable in certain circumstances. To control the multiple reverse current to unidirectional current, an adaptive control law is presented inspired from the relation between multiple reversaJs current and the chaos-periodic/quasiperiodic transition of the transport velocity. The designed controller can stabilize the transport velocity of ratchets to steady state and suppress any chaos-periodic/quasiperiodic transition, namely, the stable transport in ratchets is achieved, which makes the current sign unchanged.
文摘the system to DC voltage source as the core, AT89C52 MCU as the main controller, the output voltage to set the DC power supply through the keyboard, with a step function voltage to reality, the actual output value. This design is divided into four modules： SCM control and display module, digital to analog （D/A） conversion module, a constant voltage source module, output module. MCU control module as the core, the input signal is converted to digital quantity output; constant current source module voltage D/A conversion to analog conversion into constant pressure through a constant voltage circuit. The system has good reliability, high precision.
文摘为使装甲车辆在运行过程中获得良好工作状态,通过在基速以下区域采用基于滑模极值搜索(Sliding Mode Extreme value Search Control,SMESC)的最大转矩电流比(Maximum Torque Per Ampere,MTPA)控制算法(SMESC-MTPA)和在基速以上区域使用弱磁控制算法的方式控制电传动装甲车辆轮毂电机,并考虑电流在高速段的交叉耦合效应及电机参数变化影响,在基速以上区域使用变交轴的单电流控制法进行弱磁控制,进而搭建基于MATLAB/Simulink的仿真模型,并通过仿真验证了该控制策略的正确性。
基金Project (No.90707002) supported by the National Natural Science Foundation of China
文摘The boost type power supplies are widely used in portable consumer electronics to step up the input voltage to adapt for the high voltage applications like light-emitting diode(LED) driving and liquid crystal display(LCD) biasing.In these applications,a regulator with small volume,fewer external components and high efficiency is highly desired.This paper proposes a projected off-and on-time boost control scheme,based on which a monolithic IC with an on-chip VDMOS with 0.2 Ω on-state resistance RDS-ON was implemented in 1.5 μm bipolar-CMOS-DMOS(BCD) process.A 12 V,0.3 A boost regulator prototype is presented as well.With projected off-time and modulated on-time in continuous conduction mode(CCM),a quasi fixed frequency,which is preferred for ripple control,is realized.With projected on-time and modulated off-time in discontinuous conduction mode(DCM),pulse frequency modulation(PFM) operation,which is beneficial to light load efficiency improvement,is achieved without extra control circuitry.Measurement results show that an efficiency of 3% higher than that of a conventional method under 0.5 W output is achieved while a step load transient response comparable to that of current mode control is maintained as well.
