The explosive demands for facial masks as vital personal protection equipment(PPE)in the wake of Covid-19 have challenged many industries and enterprises in technology and capacity,and the piezoelectric ceramic(PZT)tr...The explosive demands for facial masks as vital personal protection equipment(PPE)in the wake of Covid-19 have challenged many industries and enterprises in technology and capacity,and the piezoelectric ceramic(PZT)transducers for the production of facial masks in the welding process are in heavy demand.In the earlier days of the epidemic,the supply of ceramic transducers cannot meet its increasing demands,and efforts in materials,development,and production are mobilized to provide the transducers to mask producers for quick production.The simplest solution is presented with the employment of Rayleigh-Ritz method for the vibration analysis,then different materials can be selected to achieve the required frequency and energy standards.The fully tailored method and results can be utilized by the engineers for quick development of the PZT transducers to perform precise function in welding.展开更多
Robot technology is a very promising technology for agricultural sector, but the existing industrial robot could not deliver the above-mentioned criteria. Industrial robot mainly uses high voltage electrical power, wh...Robot technology is a very promising technology for agricultural sector, but the existing industrial robot could not deliver the above-mentioned criteria. Industrial robot mainly uses high voltage electrical power, which is not available at field and outdoor operation. The only available and reliable power is a hydraulic from the tractor. The harvester robot consumes the hydraulic power from the tractor and at the same time the tractor can be used as a traveling device for the robot. This paper describes the study on the development of autonomous tractor for the oil palm harvester. The development took considerations on the design of the electro-hydraulic system and the control software for the robot structure to be flexible enough to operate in plantation environment.展开更多
Global demand for power has significantly increased, but power generation and transmission capacities have not increased proportionally with this demand. As a result, power consumers suffer from various problems, such...Global demand for power has significantly increased, but power generation and transmission capacities have not increased proportionally with this demand. As a result, power consumers suffer from various problems, such as voltage and frequency instability and power quality issues. To overcome these problems, the capacity for available power transfer of a transmission network should be enhanced. Researchers worldwide have addressed this issue by using flexible AC transmission system （FACTS） devices. We have conducted a comprehensive review of how FACTS controllers are used to enhance the avail- able transfer capability （ATC） and power transfer capability （PTC） of power system networks. This review includes a discussion of the classification of different FACTS devices according to different factors. The popularity and applications of these devices are discussed together with relevant statistics. The operating principles of six major FACTS devices and their application in increasing ATC and PTC are also presented. Finally, we evaluate the performance of FACTS devices in ATC and PTC improvement with respect to different control algorithms.展开更多
基金supported in part by the National Natural Science Foundation of China(No.11672142)the Technology Innovation 2025 Program of the Municipality of Ningbo(No.2019B10122)。
文摘The explosive demands for facial masks as vital personal protection equipment(PPE)in the wake of Covid-19 have challenged many industries and enterprises in technology and capacity,and the piezoelectric ceramic(PZT)transducers for the production of facial masks in the welding process are in heavy demand.In the earlier days of the epidemic,the supply of ceramic transducers cannot meet its increasing demands,and efforts in materials,development,and production are mobilized to provide the transducers to mask producers for quick production.The simplest solution is presented with the employment of Rayleigh-Ritz method for the vibration analysis,then different materials can be selected to achieve the required frequency and energy standards.The fully tailored method and results can be utilized by the engineers for quick development of the PZT transducers to perform precise function in welding.
文摘Robot technology is a very promising technology for agricultural sector, but the existing industrial robot could not deliver the above-mentioned criteria. Industrial robot mainly uses high voltage electrical power, which is not available at field and outdoor operation. The only available and reliable power is a hydraulic from the tractor. The harvester robot consumes the hydraulic power from the tractor and at the same time the tractor can be used as a traveling device for the robot. This paper describes the study on the development of autonomous tractor for the oil palm harvester. The development took considerations on the design of the electro-hydraulic system and the control software for the robot structure to be flexible enough to operate in plantation environment.
基金supported by the Ministry of Higher Education of Malaysia and University of Malaya under the E-Science Fund Research Grant(No.SF005-2013)the UMRG Project RP015D-13AET
文摘Global demand for power has significantly increased, but power generation and transmission capacities have not increased proportionally with this demand. As a result, power consumers suffer from various problems, such as voltage and frequency instability and power quality issues. To overcome these problems, the capacity for available power transfer of a transmission network should be enhanced. Researchers worldwide have addressed this issue by using flexible AC transmission system （FACTS） devices. We have conducted a comprehensive review of how FACTS controllers are used to enhance the avail- able transfer capability （ATC） and power transfer capability （PTC） of power system networks. This review includes a discussion of the classification of different FACTS devices according to different factors. The popularity and applications of these devices are discussed together with relevant statistics. The operating principles of six major FACTS devices and their application in increasing ATC and PTC are also presented. Finally, we evaluate the performance of FACTS devices in ATC and PTC improvement with respect to different control algorithms.
