多旋翼植保无人机是近年来新兴的植保机械,其作业高效,作业成本低廉,适应性强,可跨区域作业并且极大地减少了作业过程中与农药的接触。多旋翼植保无人机施药技术逐渐成熟,机翼旋转的下洗气流有利于在施药过程中增加药液的穿透性,并且在...多旋翼植保无人机是近年来新兴的植保机械,其作业高效,作业成本低廉,适应性强,可跨区域作业并且极大地减少了作业过程中与农药的接触。多旋翼植保无人机施药技术逐渐成熟,机翼旋转的下洗气流有利于在施药过程中增加药液的穿透性,并且在作业过程中不会发生对作物的碾压情况,很适宜在夏大豆生长中后期进行病虫害防治作业。结合当前国内外植保喷雾技术研究现状,在基础机型的田间试验后,对植保无人机进行运动理论分析和药箱内部流体的仿真测试,提出一种稳定的植保无人机机架结构,并对重要零部件进行仿真分析。通过Solid Works Simulation对零件进行仿真分析并优化模型,使机架平台结构变得更加稳定,设计出符合现代农业生产条件的多旋翼植保无人机。展开更多
The asymmetric or periodically varying blade loads resulted by wind shear become more significant as the blade length is increased to capture more wind power.Additionally,compared with the onshore wind turbines,their ...The asymmetric or periodically varying blade loads resulted by wind shear become more significant as the blade length is increased to capture more wind power.Additionally,compared with the onshore wind turbines,their offshore counterparts are subjected to additional wave loadings in addition to wind loadings within their lifetime.Therefore,vibration control and fatigue load mitigation are crucial for safe operation of large-scale offshore wind turbines.In view of this,a multi-body model of an offshore bottom-fixed wind turbine including a detailed drivetrain is established in this paper.Then,an individual pitch controller(IPC)is designed using disturbance accommodating control.State feedback is used to add damping in flexible modes of concern,and a state estimator is designed to predict unmeasured signals.Continued,a coupled aero-hydro-servo-elastic model is constructed.Based on this coupled model,the load reduction effect of IPC and the dynamic responses of the drivetrain are investigated.The results showed that the designed IPC can effectively reduce the structural loads of the wind turbine while stabilizing the turbine power out-put.Moreover,it is found that the drivetrain dynamic responses are improved under IPC.展开更多
文摘多旋翼植保无人机是近年来新兴的植保机械,其作业高效,作业成本低廉,适应性强,可跨区域作业并且极大地减少了作业过程中与农药的接触。多旋翼植保无人机施药技术逐渐成熟,机翼旋转的下洗气流有利于在施药过程中增加药液的穿透性,并且在作业过程中不会发生对作物的碾压情况,很适宜在夏大豆生长中后期进行病虫害防治作业。结合当前国内外植保喷雾技术研究现状,在基础机型的田间试验后,对植保无人机进行运动理论分析和药箱内部流体的仿真测试,提出一种稳定的植保无人机机架结构,并对重要零部件进行仿真分析。通过Solid Works Simulation对零件进行仿真分析并优化模型,使机架平台结构变得更加稳定,设计出符合现代农业生产条件的多旋翼植保无人机。
基金This paper is financially supported by the Scientific Research Foundation of Chongqing University of Technology(Grant Nos.2020ZDZ023 and 2019ZD124)the Project of Science and Technology Research Program of Chongqing Education Commission of China(Grant No.KJQN202101133)the National Natural Science Foundation Cultivation Program of Chongqing University of Technology(Grant No.2021PYZ14).
文摘The asymmetric or periodically varying blade loads resulted by wind shear become more significant as the blade length is increased to capture more wind power.Additionally,compared with the onshore wind turbines,their offshore counterparts are subjected to additional wave loadings in addition to wind loadings within their lifetime.Therefore,vibration control and fatigue load mitigation are crucial for safe operation of large-scale offshore wind turbines.In view of this,a multi-body model of an offshore bottom-fixed wind turbine including a detailed drivetrain is established in this paper.Then,an individual pitch controller(IPC)is designed using disturbance accommodating control.State feedback is used to add damping in flexible modes of concern,and a state estimator is designed to predict unmeasured signals.Continued,a coupled aero-hydro-servo-elastic model is constructed.Based on this coupled model,the load reduction effect of IPC and the dynamic responses of the drivetrain are investigated.The results showed that the designed IPC can effectively reduce the structural loads of the wind turbine while stabilizing the turbine power out-put.Moreover,it is found that the drivetrain dynamic responses are improved under IPC.
