In hydraulic area,independent metering control(IMC)technology is an effective approach to improve system efficiency and control flexibility.In addition,digital hydraulic technology(DHT)has been verified as a reasonabl...In hydraulic area,independent metering control(IMC)technology is an effective approach to improve system efficiency and control flexibility.In addition,digital hydraulic technology(DHT)has been verified as a reasonable method to optimize system dynamic performance.Integrating these two technologies into one component can combine their advantages together.However,few works focused on it.In this paper,a twin spools valve with switching technologycontrolled pilot stage(TSVSP)is presented,which applied DHT into its pilot stage while appending IMC into its main stage.Based on this prototype valve,a series of numerical and experiment analysis of its IMC performance with both simulated load and excavator boom cylinder are carried out.Results showed fast and robust performance of pressure and flow compound control with acceptable fluctuation phenomenon caused by switching technology.Rising time of flow response in excavator cylinder can be controlled within 200 ms,meanwhile,the recovery time of rod chamber pressure under suddenly changed condition is optimized within 250 ms.IMC system based on TSVSP can improve both dynamic performance and robust characteristics of the target actuator so it is practical in valve-cylinder system and can be applied in mobile machineries.展开更多
With the widespread application of the computer and microelectronic technology in the industry,digitization becomes the inevitable developing trend of the hydraulic technology.Digitization of the hydraulic components ...With the widespread application of the computer and microelectronic technology in the industry,digitization becomes the inevitable developing trend of the hydraulic technology.Digitization of the hydraulic components is critical in the digital hydraulic technology.High-speed on-of valves(HSVs)which convert a train of input pulses into the fast and accurate switching between the on and of states belong to widely used basic digital hydraulic elements.In some ways,the characteristics of the HSVs determine the performance of the digital hydraulic systems.This paper discusses the development of HSVs and their applications.First,the HSVs with innovative structures which is classifed into direct drive valves and pilot operated valves are discussed,with the emphasis on their performance.Then,an overview of HSVs with intelligent materials is presented with considering of the switching frequency and fow capacity.Finally,the applications of the HSVs are reviewed,including digital hydraulic components with the integration of the HSVs and digital hydraulic systems controlled by the HSVs.展开更多
传统的高速数据存储系统使用RAID(redundant array of independent disks)技术组建硬盘阵列以提高存储带宽与存储容量。工作过程中RAID控制器的数据分配策略、缓存性能以及单次存储操作的数据长度等因素会直接影响系统存储带宽的稳定性...传统的高速数据存储系统使用RAID(redundant array of independent disks)技术组建硬盘阵列以提高存储带宽与存储容量。工作过程中RAID控制器的数据分配策略、缓存性能以及单次存储操作的数据长度等因素会直接影响系统存储带宽的稳定性,并造成瞬时存储速度陡降。针对这一问题,提出了一种硬盘分组控制方法,该方法分为3个步骤:根据存储带宽需求组建硬盘分组;建立分组切换机制保证分组间的工作负载均衡;实时监测缓存状态,非平稳状态下当缓存长度达到安全阈值时自适应切换工作分组以保证存储系统持续稳定工作。该方法已在国家西部测绘项目实际应用并得到验证。展开更多
A new SOILIGBT（lateral insulated-gate bipolar transistor） with cathode-and anode-gates on partial membrane is proposed.A low on-state resistance is achieved when a negative voltage is applied to the anode gate.In th...A new SOILIGBT（lateral insulated-gate bipolar transistor） with cathode-and anode-gates on partial membrane is proposed.A low on-state resistance is achieved when a negative voltage is applied to the anode gate.In the blocking state,the cathode gate is shortened to the cathode and the anode gate is shortened to the anode,leading to a fast switching speed.Moreover,the removal of the partial silicon substrate under the drift region avoids collecting charges beneath the buried oxide,which releases potential lines below the membrane,yielding an enhanced breakdown voltage（BV）.Furthermore,a high switching speed is obtained due to the absence of the drain-substrate capacitance. Lastly,a combination of uniformity and variation in lateral doping profiles helps to achieve a high BV and low special on-resistance.Compared with a conventional LIGBT,the proposed structure exhibits high current capability,low special on-resistance,and double the BV.展开更多
The influence of electron irradiation on the switching speed in insulated gate bipolar transistors（IGBT） with different epitaxial layer thicknesses is discussed in detail.The experimental results prove that the fall...The influence of electron irradiation on the switching speed in insulated gate bipolar transistors（IGBT） with different epitaxial layer thicknesses is discussed in detail.The experimental results prove that the fall time of IGBT increases when increasing the thickness of the epitaxial layer.However,there is no obvious difference between the ratios of the fall time after irradiation to those before irradiation for different epitaxial layer thicknesses.The increase in switching speed of the IGBT is accompanied by an increase in the forward drop,and a trade-off curve between forward voltage drop and fall time of IGBT is presented.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.52005441,51890885)open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems(Grant No.GZKF-201906)+1 种基金Zhejiang Province Natural Science Foundation of China(Grant No.LQ21E050017)China Postdoctoral Science Foundation(Grant Nos.2021M692777,2021T140594).
文摘In hydraulic area,independent metering control(IMC)technology is an effective approach to improve system efficiency and control flexibility.In addition,digital hydraulic technology(DHT)has been verified as a reasonable method to optimize system dynamic performance.Integrating these two technologies into one component can combine their advantages together.However,few works focused on it.In this paper,a twin spools valve with switching technologycontrolled pilot stage(TSVSP)is presented,which applied DHT into its pilot stage while appending IMC into its main stage.Based on this prototype valve,a series of numerical and experiment analysis of its IMC performance with both simulated load and excavator boom cylinder are carried out.Results showed fast and robust performance of pressure and flow compound control with acceptable fluctuation phenomenon caused by switching technology.Rising time of flow response in excavator cylinder can be controlled within 200 ms,meanwhile,the recovery time of rod chamber pressure under suddenly changed condition is optimized within 250 ms.IMC system based on TSVSP can improve both dynamic performance and robust characteristics of the target actuator so it is practical in valve-cylinder system and can be applied in mobile machineries.
基金Supported by Key Technologies Research and Development Program of China(Grant No.2019YFB2004502)National Natural Science Foundation of China(Grant Nos.51805350,51775362)Postdoctoral Science Foundation of China(Grant No.2019M651073).
文摘With the widespread application of the computer and microelectronic technology in the industry,digitization becomes the inevitable developing trend of the hydraulic technology.Digitization of the hydraulic components is critical in the digital hydraulic technology.High-speed on-of valves(HSVs)which convert a train of input pulses into the fast and accurate switching between the on and of states belong to widely used basic digital hydraulic elements.In some ways,the characteristics of the HSVs determine the performance of the digital hydraulic systems.This paper discusses the development of HSVs and their applications.First,the HSVs with innovative structures which is classifed into direct drive valves and pilot operated valves are discussed,with the emphasis on their performance.Then,an overview of HSVs with intelligent materials is presented with considering of the switching frequency and fow capacity.Finally,the applications of the HSVs are reviewed,including digital hydraulic components with the integration of the HSVs and digital hydraulic systems controlled by the HSVs.
文摘传统的高速数据存储系统使用RAID(redundant array of independent disks)技术组建硬盘阵列以提高存储带宽与存储容量。工作过程中RAID控制器的数据分配策略、缓存性能以及单次存储操作的数据长度等因素会直接影响系统存储带宽的稳定性,并造成瞬时存储速度陡降。针对这一问题,提出了一种硬盘分组控制方法,该方法分为3个步骤:根据存储带宽需求组建硬盘分组;建立分组切换机制保证分组间的工作负载均衡;实时监测缓存状态,非平稳状态下当缓存长度达到安全阈值时自适应切换工作分组以保证存储系统持续稳定工作。该方法已在国家西部测绘项目实际应用并得到验证。
基金supported by the National Natural Science Foundation of China(Nos.60806025,60976060)the Youth Teacher Foundation of University of Electronic Science and Technology of China(No.jx0721)
文摘A new SOILIGBT（lateral insulated-gate bipolar transistor） with cathode-and anode-gates on partial membrane is proposed.A low on-state resistance is achieved when a negative voltage is applied to the anode gate.In the blocking state,the cathode gate is shortened to the cathode and the anode gate is shortened to the anode,leading to a fast switching speed.Moreover,the removal of the partial silicon substrate under the drift region avoids collecting charges beneath the buried oxide,which releases potential lines below the membrane,yielding an enhanced breakdown voltage（BV）.Furthermore,a high switching speed is obtained due to the absence of the drain-substrate capacitance. Lastly,a combination of uniformity and variation in lateral doping profiles helps to achieve a high BV and low special on-resistance.Compared with a conventional LIGBT,the proposed structure exhibits high current capability,low special on-resistance,and double the BV.
文摘The influence of electron irradiation on the switching speed in insulated gate bipolar transistors（IGBT） with different epitaxial layer thicknesses is discussed in detail.The experimental results prove that the fall time of IGBT increases when increasing the thickness of the epitaxial layer.However,there is no obvious difference between the ratios of the fall time after irradiation to those before irradiation for different epitaxial layer thicknesses.The increase in switching speed of the IGBT is accompanied by an increase in the forward drop,and a trade-off curve between forward voltage drop and fall time of IGBT is presented.
