Acoustic emission(AE)localization plays an important role in the prediction and control of potential hazardous sources in complex structures.However,existing location methods have less discussion on the presence of un...Acoustic emission(AE)localization plays an important role in the prediction and control of potential hazardous sources in complex structures.However,existing location methods have less discussion on the presence of unknown empty areas.This paper proposes an AE source location method for structures containing unknown empty areas(SUEA).Firstly,this method identifies the shape,size,and location of empty areas in the unknown region by exciting the active AE sources and using the collected AE arrivals.Then,the unknown AE source can be located considering the identified empty areas.The lead break experiments were performed to verify the effectiveness and accuracy of the proposed method.Five specimens were selected containing empty areas with different positions,shapes,and sizes.Results show the average location accuracy of the SUEA increased by 78%compared to the results of the existing method.It can provide a more accurate solution for locating AE sources in complex structures containing unknown empty areas such as tunnels,bridges,railroads,and caves in practical engineering.展开更多
The rapid developments of unmanned aerial vehicles(UAV)and vision sensor are contributing a great reformation in precision agriculture.Farmers can fly their UAV spraying pesticides around their crop fields while stayi...The rapid developments of unmanned aerial vehicles(UAV)and vision sensor are contributing a great reformation in precision agriculture.Farmers can fly their UAV spraying pesticides around their crop fields while staying at their remote control room or any place that is separated from their farm land.However,there is a common phenomenon in rice planting management stage that some empty areas are randomly located in farmland.Therefore,a critical problem is that the waste of pesticides that occurs when spraying pesticides over rice fields with empty areas by using the common UAV,because it is difficult to control the flow accuracy based on the empty areas changing.To tackle this problem,a novel vision-based spraying system was proposed that can identify empty areas automatically while spraying a precise amount of pesticides on the target regions.By this approach,the image was preprocessed with the Lucy-Richardson algorithm,then the target area was split from the background with k-means and the feature parameters were extracted,finally the feature parameters were filtered out with a positive contribution which would serve as the input parameters of the support vector machine(SVM)to identify the target area.Also a fuzzy control model was analyzed and exerted to compensate the nonlinearity and hysteresis of the variable rate spraying system.Experimental results proved that the approach was applicable to reducing the amount of pesticides during UAV spraying,which can provide a reference for precision agriculture aviation in the future.展开更多
基金We are grateful for the financial support from the National Science Foundation for Excellent Young Scholars of China(51822407)the Natural Science Foundation of China(51774327)+1 种基金the Special Fund for Basic Scientific Research Operations in Universities(2282020cxqd055)the Fundamental Research Funds for the Central Universities of Central South University(2021zzts0875).
文摘Acoustic emission(AE)localization plays an important role in the prediction and control of potential hazardous sources in complex structures.However,existing location methods have less discussion on the presence of unknown empty areas.This paper proposes an AE source location method for structures containing unknown empty areas(SUEA).Firstly,this method identifies the shape,size,and location of empty areas in the unknown region by exciting the active AE sources and using the collected AE arrivals.Then,the unknown AE source can be located considering the identified empty areas.The lead break experiments were performed to verify the effectiveness and accuracy of the proposed method.Five specimens were selected containing empty areas with different positions,shapes,and sizes.Results show the average location accuracy of the SUEA increased by 78%compared to the results of the existing method.It can provide a more accurate solution for locating AE sources in complex structures containing unknown empty areas such as tunnels,bridges,railroads,and caves in practical engineering.
基金We acknowledge that the research was financially supported by Research and Demonstration of Key Technologies for Water Saving in Irrigation Areas in Guangdong Province based on UAV(2016-18)Research and Demonstration of Key Technology for Precision Spraying of Agricultural UAV based on Multi-source Information(201803020022).
文摘The rapid developments of unmanned aerial vehicles(UAV)and vision sensor are contributing a great reformation in precision agriculture.Farmers can fly their UAV spraying pesticides around their crop fields while staying at their remote control room or any place that is separated from their farm land.However,there is a common phenomenon in rice planting management stage that some empty areas are randomly located in farmland.Therefore,a critical problem is that the waste of pesticides that occurs when spraying pesticides over rice fields with empty areas by using the common UAV,because it is difficult to control the flow accuracy based on the empty areas changing.To tackle this problem,a novel vision-based spraying system was proposed that can identify empty areas automatically while spraying a precise amount of pesticides on the target regions.By this approach,the image was preprocessed with the Lucy-Richardson algorithm,then the target area was split from the background with k-means and the feature parameters were extracted,finally the feature parameters were filtered out with a positive contribution which would serve as the input parameters of the support vector machine(SVM)to identify the target area.Also a fuzzy control model was analyzed and exerted to compensate the nonlinearity and hysteresis of the variable rate spraying system.Experimental results proved that the approach was applicable to reducing the amount of pesticides during UAV spraying,which can provide a reference for precision agriculture aviation in the future.
