The control platform of the induction motor (IM) with low costs is developed by using DSP MC56F8013 with a good performance/price rtaio. The control algorithm for the speed sensorless IM is studied based on the stat...The control platform of the induction motor (IM) with low costs is developed by using DSP MC56F8013 with a good performance/price rtaio. The control algorithm for the speed sensorless IM is studied based on the stator flux orientation (SFO). The algorithm structure is simple to be implemented and cannot be influenced by motor parameters, The improved stator flux estimation is used to compensate errors caused by the low pass filter (LPF). A new speed regulator is designed to ensure the system working with the maximal torque in the transient state. The system simulation and the prototype experiment are made. Results show that the con- trol system has good dynamic and static performance.展开更多
A speed sensorless vector control system of induction motor with estimated rotor speed and rotor flux using a new reduced order extended Kalman filter is proposed. With this method, two rotor flux components are sele...A speed sensorless vector control system of induction motor with estimated rotor speed and rotor flux using a new reduced order extended Kalman filter is proposed. With this method, two rotor flux components are selected as the state variables, and the rotor speed as an estimated parameter is regarded as an augmented state variable. The algorithm with reduced order decreases the computational complexity and makes the proposed estimator feasible to be implemented in real time. The simulation results show high accuracy of the estimation algorithm and good performance of speed control, and verify the usefulness of the proposed algorithm.展开更多
This paper presents an LC VCO with auto-amplitude control (AAC), in which pMOS FETs are used,and the varactors are directly connected to ground to widen the linear range of Kvco. The AAC circuitry adds little noise ...This paper presents an LC VCO with auto-amplitude control (AAC), in which pMOS FETs are used,and the varactors are directly connected to ground to widen the linear range of Kvco. The AAC circuitry adds little noise to the VCO but provides it with robust performance over a wide temperature and carrier frequency range.The VCO is fabricated in a chartered 50GHz 0.35μm SiGe BiCMOS process. The measurements show that it has - 127. 27dBc/Hz phase noise at 1MHz offset and a linear gain of 32.4MHz/V between 990MHz and 1.14GHz.The whole circuit draws 6. 6mA current from 5V supply.展开更多
In this paper, the novel control structures of differential pressure thermally coupled reactive distillation process for methyl acetate hydrolysis were proposed. The RadFrac module of Aspen Plus was adopted in the ste...In this paper, the novel control structures of differential pressure thermally coupled reactive distillation process for methyl acetate hydrolysis were proposed. The RadFrac module of Aspen Plus was adopted in the steady-state simulation. Sensitive analysis was applied to find the stable intial value and provide a basis for the improved control structure design. The Aspen Dynamics software was adopted to study the process dynamic behaviors, and two novel control structures provided with feed ratio controllers and sensitive tray temperature controllers were proposed. The reflux ratio controllers were applied in the improved novel control structures. Both control structures abandoned the composition controllers that were replaced by simpler controllers with which the product purity could meet the specification requiring under a ± 20% disturbance to the total feed flowrate / MeAc composition.展开更多
A novel speed sensor-less direct torque control induction motor drive system for the mining locomotive haulage is presented in the paper. Rotor speed identification is based on the model reference adaptive control the...A novel speed sensor-less direct torque control induction motor drive system for the mining locomotive haulage is presented in the paper. Rotor speed identification is based on the model reference adaptive control theory with neural network using back propagation algorithm. The system is implemented using a real-time TMS320F240 digital signal processor. The simulation study and experiment results indicate that the suggested system has good performance.展开更多
In this paper, we proposed a scheme based on Monte Carlo algorithm to test whether or not the nodes are redundant for realizing the node density control in the sensor network. The computational complexity is only O(n)...In this paper, we proposed a scheme based on Monte Carlo algorithm to test whether or not the nodes are redundant for realizing the node density control in the sensor network. The computational complexity is only O(n). We also established the coverage collision detection and back-off mechanism applied in the wireless sensor network. The simulation results show that the system can cover all the interested area with the smallest number of nodes and a coverage void will not appear during the course of state-transition. The coverage collision detection and back-off mechanism proposed in this article can be applied when the nodes have either synchronous or asynchronous mechanism. It also provides a stable stage with the length of the time that can be adjusted.展开更多
Plasma torch is a device that transforms electrical energy into heat carried by a gas and its safe operation is necessary to control her temperature. This paper presents the use of the Arduino board in temperature con...Plasma torch is a device that transforms electrical energy into heat carried by a gas and its safe operation is necessary to control her temperature. This paper presents the use of the Arduino board in temperature control of a plasma torch through fuzzy control. The plasma torch of this project was built so that a flow of water can circulate through your body, allowing its cooling. The cooling system mounted consists of one radiator, one expansion vase, one water pump and one temperature sensor. The heated water coming the plasma torch is passed by the temperature sensor. This is converted in a voltage and read by an analog input port of the Arduino. This processes the information received and makes the decision to turn on/off the radiator fan and/or powered the frequency inverter water pump to control the temperature. The graph of the fuzzy control showed an oscillation between 104 °F to 122 °F around the chosen reference 113 °F. The results show that it is possible to control the temperature of a plasma torch using the Arduino board and fuzzy logic.展开更多
In this study,the effects of ‘initial’ soil moisture(SM) in arid and semi-arid Northwestern China on subsequent climate were investigated with a regional climate model. Besides the control simulations(denoted as CTL...In this study,the effects of ‘initial’ soil moisture(SM) in arid and semi-arid Northwestern China on subsequent climate were investigated with a regional climate model. Besides the control simulations(denoted as CTL),a series of sensitivity experiments were conducted,including the DRY and WET experiments,in which the simulated ‘initial’ SM over the region 30 –50°N,75 –105°E was only 5% and 50%,and up to 150% and 200% of the simulated value in the CTL,respectively. The results show that SM change can modify the subsequent climate in not only the SM-change region proper but also the far downstream regions in Eastern and even Northeastern China. The SM-change effects are generally more prominent in the WET than in the DRY experiments. After the SM is initially increased,the SM in the SM-change region is always higher than that in the CTL,the latent(sensible) heat flux there increases(decreases),and the surface air temperature decreases. Spatially,the most prominent changes in the WET experiments are surface air temperature decrease,geopotential height decrease and corresponding abnormal changes of cyclonic wind vectors at the mid-upper troposphere levels. Generally opposite effects exist in the DRY experiments but with much weaker intensity. In addition,the differences between the results obtained from the two sets of sensitivity experiments and those of the CTL are not always consistent with the variation of the initial SM. Being different from the variation of temperature,the rainfall modifications caused by initial SM change are not so distinct and in fact they show some common features in the WET and DRY experiments. This might imply that SM is only one of the factors that impact the subsequent climate,and its effect is involved in complex processes within the atmosphere,which needs further investigation.展开更多
This is a greenhouse ecological parameters measurement and control system, the system implements the data collection of field temperature, humidity and carbon dioxide by using the 1-wire bus network which consist of 1...This is a greenhouse ecological parameters measurement and control system, the system implements the data collection of field temperature, humidity and carbon dioxide by using the 1-wire bus network which consist of 1-wire bus temperature sensor, 1-wire bus humidity sensor, Analog-to-Digital Converter(ADC), CO2 sensor and intelligent battery monitor.展开更多
This paper presents a speed sensorless vector control system for induction machine (IM),which is based on a flux observer. According to vector control theory of IM,the q-axis rotor flux converging on zero is utilized ...This paper presents a speed sensorless vector control system for induction machine (IM),which is based on a flux observer. According to vector control theory of IM,the q-axis rotor flux converging on zero is utilized for speed estimation. Additionally this system solved the online identification of stator resistance by d-axis flux error. The advantages of the proposed system are simplicity and avoidance of the problems caused by only using a voltage model. The effectiveness of the proposed system has been verified by simulation and experimentation.展开更多
Vaccines are used in integrated control strategies to guard poultry against H5N1 high-pathogenicity avian influenza (AI). This study was to evaluate the efficacy of AI vaccine against AI in poultry. About 400 serum ...Vaccines are used in integrated control strategies to guard poultry against H5N1 high-pathogenicity avian influenza (AI). This study was to evaluate the efficacy of AI vaccine against AI in poultry. About 400 serum samples were collected from the selected 130 farms located at Rajshahi region, Bangladesh. The study was carried out from January, 2013 to January, 2015. The AI vaccine titres were compared in different breed of layer, environmental temperature, feed and egg production. Result showed that the value of titres (mean ± SD) in Hyline brown, Hyline white, Bovans white and Novogen white were 6.71 ± 0.05, 6.67 ± 0.06, 6.79 ± 0.03 and 6.43 ± 0.04, respectively. The highest serum antibody titres were 6.61 ± 0.24 against AI antibody in 〉 26 ℃ environment temperature. The highest and lowest serum antibody value of AI against feed brand (nutrient) were 7.75 ± 0.08 and 5.58 ± 0.22 for Aftab and Quality brand feed, respectively.展开更多
This paper presents the control ofa WECS (wind energy conversion system), equipped with a DFIG (doubly fed induction generator), for maximum power generation and power quality improvement simultaneously. The propo...This paper presents the control ofa WECS (wind energy conversion system), equipped with a DFIG (doubly fed induction generator), for maximum power generation and power quality improvement simultaneously. The proposed control algorithm is applied to a DFIG whose stator is directly connected to the grid and the rotor is connected to the grid through a back-to-back AC-DC-AC PWM (pulse width modulation) converter. The RSC (rotor side converter) is controlled in such a way to extract a maximum power, for a wide range of wind speed. The GSC (grid side converter) is controlled in order to filter harmonic currents of a nonlinear load coupled at the PCC (point of common coupling) and ensure smooth DC bus voltage. Simulation results show that the wind turbine can operate at its optimum energy for a wide range of wind speed and power quality improvement is achieved.展开更多
For the problem posed by closely spaced modes, this paper defined the MCC (modal correlation criterion) to measure the degree of correlation between close modes. It was proved that structures with certain features ten...For the problem posed by closely spaced modes, this paper defined the MCC (modal correlation criterion) to measure the degree of correlation between close modes. It was proved that structures with certain features tend to have closely clustered modes and the corresponding mode shapes highly correlated. With this understanding, the closed-form expressions for controllability and observability Grammians were adopted to analyze the impacts of actuator/sensor placement on the controllability/observability of highly correlated close modes. On this basis, the problem of actuator/sensor placement, when the optimization criterion is based on modal controllability/observability, was simplified. Moreover, the dimension of the control/measurement vector in independent modal space control for highly correlated close modes was proved to have the potential to be reduced, therefore fewer actuators and sensors were required in this dimension-reduced control strategy. Finally, the desirable vibration suppression for an example structure showed that the theory and methods of this paper were accurate and effective.展开更多
We demonstrate a pH sensor based on ultrasensitive nanosize Schottky junctions formed within bottom-up grown dopant-flee arrays of assembled silicon nanowires. A new measurement concept relying on a continuous gate sw...We demonstrate a pH sensor based on ultrasensitive nanosize Schottky junctions formed within bottom-up grown dopant-flee arrays of assembled silicon nanowires. A new measurement concept relying on a continuous gate sweep is presented, which allows the straightforward determination of the point of maximum sensitivity of the device and allows sensing experiments to be performed in the optimum regime. Integration of devices into a portable fluidic system and an electrode isolation strategy affords a stable environment and enables long time robust FET sensing measurements in a liquid environment to be carried out. Investigations of the physical and chemical sensitivity of our devices at different pH values and a comparison with theoretical limits are also discussed. We believe that such a combination of nanofabrication and engineering advances makes this Schottky barrier-powered silicon nanowire lab-on-a-chip platform suitable for efficient biodetection and even for more complex biochemical analysis.展开更多
文摘The control platform of the induction motor (IM) with low costs is developed by using DSP MC56F8013 with a good performance/price rtaio. The control algorithm for the speed sensorless IM is studied based on the stator flux orientation (SFO). The algorithm structure is simple to be implemented and cannot be influenced by motor parameters, The improved stator flux estimation is used to compensate errors caused by the low pass filter (LPF). A new speed regulator is designed to ensure the system working with the maximal torque in the transient state. The system simulation and the prototype experiment are made. Results show that the con- trol system has good dynamic and static performance.
文摘A speed sensorless vector control system of induction motor with estimated rotor speed and rotor flux using a new reduced order extended Kalman filter is proposed. With this method, two rotor flux components are selected as the state variables, and the rotor speed as an estimated parameter is regarded as an augmented state variable. The algorithm with reduced order decreases the computational complexity and makes the proposed estimator feasible to be implemented in real time. The simulation results show high accuracy of the estimation algorithm and good performance of speed control, and verify the usefulness of the proposed algorithm.
文摘This paper presents an LC VCO with auto-amplitude control (AAC), in which pMOS FETs are used,and the varactors are directly connected to ground to widen the linear range of Kvco. The AAC circuitry adds little noise to the VCO but provides it with robust performance over a wide temperature and carrier frequency range.The VCO is fabricated in a chartered 50GHz 0.35μm SiGe BiCMOS process. The measurements show that it has - 127. 27dBc/Hz phase noise at 1MHz offset and a linear gain of 32.4MHz/V between 990MHz and 1.14GHz.The whole circuit draws 6. 6mA current from 5V supply.
基金supported financially by the Fundamental Research Funds for the Central Universities (Grant No.18CX02120A)the Promotive Research Fund for Excellent Young and Middle-aged Scientists of Shandong Province(Grant No. BS2014NJ010)the National Natural Science Foundation of China (Grant No. 21506255)
文摘In this paper, the novel control structures of differential pressure thermally coupled reactive distillation process for methyl acetate hydrolysis were proposed. The RadFrac module of Aspen Plus was adopted in the steady-state simulation. Sensitive analysis was applied to find the stable intial value and provide a basis for the improved control structure design. The Aspen Dynamics software was adopted to study the process dynamic behaviors, and two novel control structures provided with feed ratio controllers and sensitive tray temperature controllers were proposed. The reflux ratio controllers were applied in the improved novel control structures. Both control structures abandoned the composition controllers that were replaced by simpler controllers with which the product purity could meet the specification requiring under a ± 20% disturbance to the total feed flowrate / MeAc composition.
文摘A novel speed sensor-less direct torque control induction motor drive system for the mining locomotive haulage is presented in the paper. Rotor speed identification is based on the model reference adaptive control theory with neural network using back propagation algorithm. The system is implemented using a real-time TMS320F240 digital signal processor. The simulation study and experiment results indicate that the suggested system has good performance.
文摘In this paper, we proposed a scheme based on Monte Carlo algorithm to test whether or not the nodes are redundant for realizing the node density control in the sensor network. The computational complexity is only O(n). We also established the coverage collision detection and back-off mechanism applied in the wireless sensor network. The simulation results show that the system can cover all the interested area with the smallest number of nodes and a coverage void will not appear during the course of state-transition. The coverage collision detection and back-off mechanism proposed in this article can be applied when the nodes have either synchronous or asynchronous mechanism. It also provides a stable stage with the length of the time that can be adjusted.
文摘Plasma torch is a device that transforms electrical energy into heat carried by a gas and its safe operation is necessary to control her temperature. This paper presents the use of the Arduino board in temperature control of a plasma torch through fuzzy control. The plasma torch of this project was built so that a flow of water can circulate through your body, allowing its cooling. The cooling system mounted consists of one radiator, one expansion vase, one water pump and one temperature sensor. The heated water coming the plasma torch is passed by the temperature sensor. This is converted in a voltage and read by an analog input port of the Arduino. This processes the information received and makes the decision to turn on/off the radiator fan and/or powered the frequency inverter water pump to control the temperature. The graph of the fuzzy control showed an oscillation between 104 °F to 122 °F around the chosen reference 113 °F. The results show that it is possible to control the temperature of a plasma torch using the Arduino board and fuzzy logic.
基金supported by the Ministry of Science and Technology of China public welfare funding (No. 2002DIB20070)the National Basic Research Program of China (973 Program) (No. 2007CB411505).
文摘In this study,the effects of ‘initial’ soil moisture(SM) in arid and semi-arid Northwestern China on subsequent climate were investigated with a regional climate model. Besides the control simulations(denoted as CTL),a series of sensitivity experiments were conducted,including the DRY and WET experiments,in which the simulated ‘initial’ SM over the region 30 –50°N,75 –105°E was only 5% and 50%,and up to 150% and 200% of the simulated value in the CTL,respectively. The results show that SM change can modify the subsequent climate in not only the SM-change region proper but also the far downstream regions in Eastern and even Northeastern China. The SM-change effects are generally more prominent in the WET than in the DRY experiments. After the SM is initially increased,the SM in the SM-change region is always higher than that in the CTL,the latent(sensible) heat flux there increases(decreases),and the surface air temperature decreases. Spatially,the most prominent changes in the WET experiments are surface air temperature decrease,geopotential height decrease and corresponding abnormal changes of cyclonic wind vectors at the mid-upper troposphere levels. Generally opposite effects exist in the DRY experiments but with much weaker intensity. In addition,the differences between the results obtained from the two sets of sensitivity experiments and those of the CTL are not always consistent with the variation of the initial SM. Being different from the variation of temperature,the rainfall modifications caused by initial SM change are not so distinct and in fact they show some common features in the WET and DRY experiments. This might imply that SM is only one of the factors that impact the subsequent climate,and its effect is involved in complex processes within the atmosphere,which needs further investigation.
文摘This is a greenhouse ecological parameters measurement and control system, the system implements the data collection of field temperature, humidity and carbon dioxide by using the 1-wire bus network which consist of 1-wire bus temperature sensor, 1-wire bus humidity sensor, Analog-to-Digital Converter(ADC), CO2 sensor and intelligent battery monitor.
文摘This paper presents a speed sensorless vector control system for induction machine (IM),which is based on a flux observer. According to vector control theory of IM,the q-axis rotor flux converging on zero is utilized for speed estimation. Additionally this system solved the online identification of stator resistance by d-axis flux error. The advantages of the proposed system are simplicity and avoidance of the problems caused by only using a voltage model. The effectiveness of the proposed system has been verified by simulation and experimentation.
文摘Vaccines are used in integrated control strategies to guard poultry against H5N1 high-pathogenicity avian influenza (AI). This study was to evaluate the efficacy of AI vaccine against AI in poultry. About 400 serum samples were collected from the selected 130 farms located at Rajshahi region, Bangladesh. The study was carried out from January, 2013 to January, 2015. The AI vaccine titres were compared in different breed of layer, environmental temperature, feed and egg production. Result showed that the value of titres (mean ± SD) in Hyline brown, Hyline white, Bovans white and Novogen white were 6.71 ± 0.05, 6.67 ± 0.06, 6.79 ± 0.03 and 6.43 ± 0.04, respectively. The highest serum antibody titres were 6.61 ± 0.24 against AI antibody in 〉 26 ℃ environment temperature. The highest and lowest serum antibody value of AI against feed brand (nutrient) were 7.75 ± 0.08 and 5.58 ± 0.22 for Aftab and Quality brand feed, respectively.
文摘This paper presents the control ofa WECS (wind energy conversion system), equipped with a DFIG (doubly fed induction generator), for maximum power generation and power quality improvement simultaneously. The proposed control algorithm is applied to a DFIG whose stator is directly connected to the grid and the rotor is connected to the grid through a back-to-back AC-DC-AC PWM (pulse width modulation) converter. The RSC (rotor side converter) is controlled in such a way to extract a maximum power, for a wide range of wind speed. The GSC (grid side converter) is controlled in order to filter harmonic currents of a nonlinear load coupled at the PCC (point of common coupling) and ensure smooth DC bus voltage. Simulation results show that the wind turbine can operate at its optimum energy for a wide range of wind speed and power quality improvement is achieved.
基金supported by the National Natural Science Foundation of China (Grant No. 10872028)
文摘For the problem posed by closely spaced modes, this paper defined the MCC (modal correlation criterion) to measure the degree of correlation between close modes. It was proved that structures with certain features tend to have closely clustered modes and the corresponding mode shapes highly correlated. With this understanding, the closed-form expressions for controllability and observability Grammians were adopted to analyze the impacts of actuator/sensor placement on the controllability/observability of highly correlated close modes. On this basis, the problem of actuator/sensor placement, when the optimization criterion is based on modal controllability/observability, was simplified. Moreover, the dimension of the control/measurement vector in independent modal space control for highly correlated close modes was proved to have the potential to be reduced, therefore fewer actuators and sensors were required in this dimension-reduced control strategy. Finally, the desirable vibration suppression for an example structure showed that the theory and methods of this paper were accurate and effective.
文摘We demonstrate a pH sensor based on ultrasensitive nanosize Schottky junctions formed within bottom-up grown dopant-flee arrays of assembled silicon nanowires. A new measurement concept relying on a continuous gate sweep is presented, which allows the straightforward determination of the point of maximum sensitivity of the device and allows sensing experiments to be performed in the optimum regime. Integration of devices into a portable fluidic system and an electrode isolation strategy affords a stable environment and enables long time robust FET sensing measurements in a liquid environment to be carried out. Investigations of the physical and chemical sensitivity of our devices at different pH values and a comparison with theoretical limits are also discussed. We believe that such a combination of nanofabrication and engineering advances makes this Schottky barrier-powered silicon nanowire lab-on-a-chip platform suitable for efficient biodetection and even for more complex biochemical analysis.