This job focuses on the stroke regulation of a class of high-precision metering pumps.A parametertuning method of robust non-fragile PID（proportional-integral-derivative）controllers is proposed with the assumption t...This job focuses on the stroke regulation of a class of high-precision metering pumps.A parametertuning method of robust non-fragile PID（proportional-integral-derivative）controllers is proposed with the assumption that a PID controller has additive gain perturbations.An H-infinite robust PID controller can be obtained by solving a linear matrix inequality.This approach can guarantee that the closed-loop control systems is asymptotically stable and the H-infinite norm of the transfer function from the disturbance to the output of a controlled system is less than a given constant to attenuate disturbances.The simulation case shows that the control performance of the proposed strategy is significantly better than the traditional PID approach in the situation with perturbations of controller parameters.展开更多
The main requirement of a vector controller is knowing the magnitude and position of the rotating flow in the rotor. This feature permits to use either flow sensors or flow estimators. The solution chosen was the esti...The main requirement of a vector controller is knowing the magnitude and position of the rotating flow in the rotor. This feature permits to use either flow sensors or flow estimators. The solution chosen was the estimation of rotor flux with the hybrid neuro-fuzzy system. The motor characteristics are： 3.75 kW （5 HP）, two pole-pair, operate at 60 Hz and air-gap length 0.2 mm. The ANFIS （adaptive neuro-fuzzy inference system） was used to tune the membership functions in fuzzy system. The hybrid estimator aims at compensating possible parametric variations of the machine caused by agents, such as temperature or nucleus saturation. The simulated results have shown good performance.展开更多
The weighing system designed for large structure object is mainly composed of three parts. The part of hydraulic system is made up of hydraulic cylinders, high pressure hydraulic hoses and electric pumps; the part of ...The weighing system designed for large structure object is mainly composed of three parts. The part of hydraulic system is made up of hydraulic cylinders, high pressure hydraulic hoses and electric pumps; the part of computer controlling system comprises pressure sensors, displacement sensors, data acquisitions, RS 485 network and the computer controlling model; the part of loading system is composed of the fulcrum structure and the concrete girder. The measurement principle and composition of the weighing system are discussed in this paper. Credibility and security of the weighing system are fully considered during the design phase. The hydraulic system is controlled by pilot operated check valves in case of the sudden loss of system pressure. The states of all gauges and RS485 network are monitored by computer controlling system functioning in different modules. When the system is running incorrectly, it will be switched to manual mode and give alarm. The finite element method is employed to analyze fulcrum structure so that the system has enough intensity to be lifted. Hence the reliability of the whole system is enhanced.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
The study presents possibilities for reconstruction of electric power supply systems in Bulgarian Black Sea resorts and possibilities to use statistical methods in energy planning. The paper shows the use of classic s...The study presents possibilities for reconstruction of electric power supply systems in Bulgarian Black Sea resorts and possibilities to use statistical methods in energy planning. The paper shows the use of classic statistical methods in combination with advanced digital measurement systems in order to obtain the correlation dependencies, nature of energy consumption and opportunities for energy forecasting. The main purpose of the study is to obtain statistical dependencies of the nature of power consumption and correlations between electricity consumption and ambient temperature in order to improve the accuracy of energy planning. The analysis includes application of energy management systems for proper energy planning, improving economical efficiency and reducing power and energy losses.展开更多
Space nuclear power system is the key technology for deep space exploration missions in the future, especially for space base building-up. This paper evaluates several typical latest space nuclear reactor system （SNR...Space nuclear power system is the key technology for deep space exploration missions in the future, especially for space base building-up. This paper evaluates several typical latest space nuclear reactor system （SNRS） designs, and finds that most of their weights are heavier than necessary. From the point of weight-control, the SA4 design is the best but its design is more complex than others. A newly designed SNRS, based on the SAFE400 model, uses annular fuel and has better performance, with a fuel mass lower than that of the SAFE400 prototype by 18.75%. Meanwhile, different from former opinions, the delay neutron fractions of SNRS are not constant and change with the different SNRS designs. Therefore, designs of SNRS not to count the delayed neutron fracture or directly to consider it as 0.00677 are not appropriate.展开更多
基金Supported by the National Natural Science Foundation of China（60604015） the Key Research Program of Education Department of Zhejiang Province（Z200803521）
文摘This job focuses on the stroke regulation of a class of high-precision metering pumps.A parametertuning method of robust non-fragile PID（proportional-integral-derivative）controllers is proposed with the assumption that a PID controller has additive gain perturbations.An H-infinite robust PID controller can be obtained by solving a linear matrix inequality.This approach can guarantee that the closed-loop control systems is asymptotically stable and the H-infinite norm of the transfer function from the disturbance to the output of a controlled system is less than a given constant to attenuate disturbances.The simulation case shows that the control performance of the proposed strategy is significantly better than the traditional PID approach in the situation with perturbations of controller parameters.
文摘The main requirement of a vector controller is knowing the magnitude and position of the rotating flow in the rotor. This feature permits to use either flow sensors or flow estimators. The solution chosen was the estimation of rotor flux with the hybrid neuro-fuzzy system. The motor characteristics are： 3.75 kW （5 HP）, two pole-pair, operate at 60 Hz and air-gap length 0.2 mm. The ANFIS （adaptive neuro-fuzzy inference system） was used to tune the membership functions in fuzzy system. The hybrid estimator aims at compensating possible parametric variations of the machine caused by agents, such as temperature or nucleus saturation. The simulated results have shown good performance.
文摘The weighing system designed for large structure object is mainly composed of three parts. The part of hydraulic system is made up of hydraulic cylinders, high pressure hydraulic hoses and electric pumps; the part of computer controlling system comprises pressure sensors, displacement sensors, data acquisitions, RS 485 network and the computer controlling model; the part of loading system is composed of the fulcrum structure and the concrete girder. The measurement principle and composition of the weighing system are discussed in this paper. Credibility and security of the weighing system are fully considered during the design phase. The hydraulic system is controlled by pilot operated check valves in case of the sudden loss of system pressure. The states of all gauges and RS485 network are monitored by computer controlling system functioning in different modules. When the system is running incorrectly, it will be switched to manual mode and give alarm. The finite element method is employed to analyze fulcrum structure so that the system has enough intensity to be lifted. Hence the reliability of the whole system is enhanced.
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The study presents possibilities for reconstruction of electric power supply systems in Bulgarian Black Sea resorts and possibilities to use statistical methods in energy planning. The paper shows the use of classic statistical methods in combination with advanced digital measurement systems in order to obtain the correlation dependencies, nature of energy consumption and opportunities for energy forecasting. The main purpose of the study is to obtain statistical dependencies of the nature of power consumption and correlations between electricity consumption and ambient temperature in order to improve the accuracy of energy planning. The analysis includes application of energy management systems for proper energy planning, improving economical efficiency and reducing power and energy losses.
文摘Space nuclear power system is the key technology for deep space exploration missions in the future, especially for space base building-up. This paper evaluates several typical latest space nuclear reactor system （SNRS） designs, and finds that most of their weights are heavier than necessary. From the point of weight-control, the SA4 design is the best but its design is more complex than others. A newly designed SNRS, based on the SAFE400 model, uses annular fuel and has better performance, with a fuel mass lower than that of the SAFE400 prototype by 18.75%. Meanwhile, different from former opinions, the delay neutron fractions of SNRS are not constant and change with the different SNRS designs. Therefore, designs of SNRS not to count the delayed neutron fracture or directly to consider it as 0.00677 are not appropriate.
