Switch electro-hydraulic proportional amplifier（PA） widely employs single switch modulation power driving（SSMPD） or reverse discharging power driving（RDPD） at present. SSMPD has slow dynamic response, and can＇t...Switch electro-hydraulic proportional amplifier（PA） widely employs single switch modulation power driving（SSMPD） or reverse discharging power driving（RDPD） at present. SSMPD has slow dynamic response, and can＇t adjust independently the dither signal＇s amplitude and frequency; RDPD accelerates the current decay; consequently, it increases current ripple and power loss. For the purpose of solving the above mentioned problem, the tri-state modulation power driving（TSMPD） scheme was proposed for improving the performance of power driving. Detailedly, the hardware circuit for the tri-state modulation power driving is designed; the tri-state modulation algorithm is realized by digital signal processor（DSP）. The tri-state modulation power driving is investigated by experiments, comparetive experiments among the single switch modulation power driving（SSMPD）, reverse discharging power driving（RDPD）, and the TSMPD are implemented, and the experimental results demonstrate that the linearity error of TSMDP meets the requirement of PA; the current response of TSMSP is the best; the amplitude of ripple current of the TSMPD can be reduced without increasing frequency of PWM, in addition, dither signal amplitude and frequency can be adjusted independently for each other. It is very meaningful to guide the development of high performance proportional amplifier for high frequency response proportional solenoid.展开更多
Current high power load simulators are generally incapable of obtaining both high loading performance and high energy efficiency. Simulators with high energy efficiency are used to simulate static-state load, and thos...Current high power load simulators are generally incapable of obtaining both high loading performance and high energy efficiency. Simulators with high energy efficiency are used to simulate static-state load, and those with high dynamic performance typically have low energy efficiency. In this paper, the variants of secondary control（VSC） with power recovery are developed to solve this problem for loading hydraulic driving devices that operate under variable pressure, unlike classical secondary control（CSC） that operates in constant pressure network. Hydrostatic secondary control units are used as the loading components, by which the absorbed mechanical power from the tested device is converted into hydraulic power and then fed back into the tested system through 4 types of feedback passages（FPs）. The loading subsystem can operate in constant pressure network, controlled variable pressure network, or the same variable pressure network as that of the tested device by using different FPs. The 4 types of systems are defined, and their key techniques are analyzed, including work principle, simulating the work state of original tested device, static operation points, loading performance, energy efficiency, and control strategy, etc. The important technical merits of the 4 schemes are compared, and 3 of the schemes are selected, designed, simulated using AMESim and evaluated. The researching results show that the investigated systems can simulate the given loads effectively, realize the work conditions of the tested device, and furthermore attain a high power recovery efficiency that ranges from 0.54 to 0.85, even though the 3 schemes have different loading performances and energy efficiencies. This paper proposes several loading schemes that can achieve both high dynamic performance and high power recovery efficiency.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
An electric seeder for small-size vegetable seeds was designed based on the power drive and the optical fiber detection technology.The seeder is driven by electric power during the sowing process.At the same time,usin...An electric seeder for small-size vegetable seeds was designed based on the power drive and the optical fiber detection technology.The seeder is driven by electric power during the sowing process.At the same time,using the fiber sensor technology to monitor the sowing condition,the seeder is more efficient with high seeding precision in terms of different seed sizes.In order to achieve the precision seeding for the 2-10 mm seeds,the driving motor is equipped in the rear crackle.The power drive reduces pollution and dyeing.Also the other components of the electric seeder were modularly designed.The seeder was designed with buckle,which could be quickly disassembled on the sowing machine to replace the sowing wheel.It can quickly adjust row spacing and sowing depth during sowing process to meet the requirements of agricultural planting.Field test was carried out for coriander,pakchoi,and radish on the accuracy and monitoring of the system,respectively.The results showed that during the field operation,the sowing precision of the sowing machine was 95%.When the seeder worked at the speeds of 3 km/h and 4 km/h,the relative error of the monitoring precision of the system was less than 6%.This system can meet the real-time monitoring requirements of the seed metering device and improve the quality of the sowing work.展开更多
基金supported by National Basic Research and Development Program of China (973 Program, Grant No. 2007CB714000)National Natural Science Foundation of China (Grant No. 50875233)
文摘Switch electro-hydraulic proportional amplifier（PA） widely employs single switch modulation power driving（SSMPD） or reverse discharging power driving（RDPD） at present. SSMPD has slow dynamic response, and can＇t adjust independently the dither signal＇s amplitude and frequency; RDPD accelerates the current decay; consequently, it increases current ripple and power loss. For the purpose of solving the above mentioned problem, the tri-state modulation power driving（TSMPD） scheme was proposed for improving the performance of power driving. Detailedly, the hardware circuit for the tri-state modulation power driving is designed; the tri-state modulation algorithm is realized by digital signal processor（DSP）. The tri-state modulation power driving is investigated by experiments, comparetive experiments among the single switch modulation power driving（SSMPD）, reverse discharging power driving（RDPD）, and the TSMPD are implemented, and the experimental results demonstrate that the linearity error of TSMDP meets the requirement of PA; the current response of TSMSP is the best; the amplitude of ripple current of the TSMPD can be reduced without increasing frequency of PWM, in addition, dither signal amplitude and frequency can be adjusted independently for each other. It is very meaningful to guide the development of high performance proportional amplifier for high frequency response proportional solenoid.
文摘Current high power load simulators are generally incapable of obtaining both high loading performance and high energy efficiency. Simulators with high energy efficiency are used to simulate static-state load, and those with high dynamic performance typically have low energy efficiency. In this paper, the variants of secondary control（VSC） with power recovery are developed to solve this problem for loading hydraulic driving devices that operate under variable pressure, unlike classical secondary control（CSC） that operates in constant pressure network. Hydrostatic secondary control units are used as the loading components, by which the absorbed mechanical power from the tested device is converted into hydraulic power and then fed back into the tested system through 4 types of feedback passages（FPs）. The loading subsystem can operate in constant pressure network, controlled variable pressure network, or the same variable pressure network as that of the tested device by using different FPs. The 4 types of systems are defined, and their key techniques are analyzed, including work principle, simulating the work state of original tested device, static operation points, loading performance, energy efficiency, and control strategy, etc. The important technical merits of the 4 schemes are compared, and 3 of the schemes are selected, designed, simulated using AMESim and evaluated. The researching results show that the investigated systems can simulate the given loads effectively, realize the work conditions of the tested device, and furthermore attain a high power recovery efficiency that ranges from 0.54 to 0.85, even though the 3 schemes have different loading performances and energy efficiencies. This paper proposes several loading schemes that can achieve both high dynamic performance and high power recovery efficiency.
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.
基金The work was sponsored by the National Key Research and Development Program of China Sub-project(No.2017YFD0700502)the Innovation Scientists and Technicians Troop Construction Projects of Henan Province(No.184200510017)+1 种基金Key Research and Development Program of Yunnan Province(No.2018ZC001)the key scientific and technological projects of Henan Province(No.172102110021).
文摘An electric seeder for small-size vegetable seeds was designed based on the power drive and the optical fiber detection technology.The seeder is driven by electric power during the sowing process.At the same time,using the fiber sensor technology to monitor the sowing condition,the seeder is more efficient with high seeding precision in terms of different seed sizes.In order to achieve the precision seeding for the 2-10 mm seeds,the driving motor is equipped in the rear crackle.The power drive reduces pollution and dyeing.Also the other components of the electric seeder were modularly designed.The seeder was designed with buckle,which could be quickly disassembled on the sowing machine to replace the sowing wheel.It can quickly adjust row spacing and sowing depth during sowing process to meet the requirements of agricultural planting.Field test was carried out for coriander,pakchoi,and radish on the accuracy and monitoring of the system,respectively.The results showed that during the field operation,the sowing precision of the sowing machine was 95%.When the seeder worked at the speeds of 3 km/h and 4 km/h,the relative error of the monitoring precision of the system was less than 6%.This system can meet the real-time monitoring requirements of the seed metering device and improve the quality of the sowing work.
