Quadrotor helicopter is emerging as a popular platform for unmanned aerial vehicle re- search, due to its simplicity of structure and maintenance as well as the capability of hovering and vertical take-off and landing...Quadrotor helicopter is emerging as a popular platform for unmanned aerial vehicle re- search, due to its simplicity of structure and maintenance as well as the capability of hovering and vertical take-off and landing. The attitude controller is an important feature of quadrotor helicopter since it allows the vehicle to keep balance and perform the desired maneuver. In this paper, nonlin- ear control strategies including active disturbance rejection control （ADRC）, sliding mode control （SMC） and backstepping method are studied and implemented to stabilize the attitude of a 3-DOF hover system. ADRC is an error-driven control law, with extended state observer （ESO） estimating the unmodeled inner dynamics and external disturbance to dynamically compensate their impacts. Meanwhile; both backstepping technique and SMC are developed based on the mathematical model, whose stability is ensured by Lyapunov global stability theorem. Furthermore, the performance of each control algorithm is evaluated by experiments. The results validate effectiveness of the strate- gies for attitude regulation. Finally, the respective characteristics of the three controllers are high- lighted by-comparison, and conclusions are drawn on the basis of the theoretical and experimental a- nalysis.展开更多
目的:了解国内疾控系统生物安全三级实验室(以下简称“BSL-3实验室”)关键生物安全防护设备的使用现况,为推进国内高等级生物安全实验室关键生物安全防护设备的研发与应用提供参考。方法:利用中国疾控中心流行病学动态数据采集(epidemio...目的:了解国内疾控系统生物安全三级实验室(以下简称“BSL-3实验室”)关键生物安全防护设备的使用现况,为推进国内高等级生物安全实验室关键生物安全防护设备的研发与应用提供参考。方法:利用中国疾控中心流行病学动态数据采集(epidemiological dynamic data collection,EDDC)平台在网上填报、收集信息,运用描述性研究的方法分析生物安全柜、气(汽)体消毒装置、压力蒸汽灭菌器和生物安全型高效空气过滤装置4种设备的品牌、国产/进口占比、使用类型、价格等现况。结果:国内疾控系统BSL-3实验室中生物安全柜、气(汽)体消毒装置和压力蒸汽灭菌器的进口率高于国产率,生物安全型高效空气过滤装置国产化程度较高,各类设备的品牌呈多样化。结论:建议国家和地方管理部门加大对国产产品的扶持力度,鼓励相关企业自主研发实验室关键生物安全防护设备,提升国内实验室设施、设备技术质量,实现由进口为主向自主保障的转变。展开更多
基金Supported by the National Key Technology R&D Program of China(201011080)
文摘Quadrotor helicopter is emerging as a popular platform for unmanned aerial vehicle re- search, due to its simplicity of structure and maintenance as well as the capability of hovering and vertical take-off and landing. The attitude controller is an important feature of quadrotor helicopter since it allows the vehicle to keep balance and perform the desired maneuver. In this paper, nonlin- ear control strategies including active disturbance rejection control （ADRC）, sliding mode control （SMC） and backstepping method are studied and implemented to stabilize the attitude of a 3-DOF hover system. ADRC is an error-driven control law, with extended state observer （ESO） estimating the unmodeled inner dynamics and external disturbance to dynamically compensate their impacts. Meanwhile; both backstepping technique and SMC are developed based on the mathematical model, whose stability is ensured by Lyapunov global stability theorem. Furthermore, the performance of each control algorithm is evaluated by experiments. The results validate effectiveness of the strate- gies for attitude regulation. Finally, the respective characteristics of the three controllers are high- lighted by-comparison, and conclusions are drawn on the basis of the theoretical and experimental a- nalysis.
文摘目的:了解国内疾控系统生物安全三级实验室(以下简称“BSL-3实验室”)关键生物安全防护设备的使用现况,为推进国内高等级生物安全实验室关键生物安全防护设备的研发与应用提供参考。方法:利用中国疾控中心流行病学动态数据采集(epidemiological dynamic data collection,EDDC)平台在网上填报、收集信息,运用描述性研究的方法分析生物安全柜、气(汽)体消毒装置、压力蒸汽灭菌器和生物安全型高效空气过滤装置4种设备的品牌、国产/进口占比、使用类型、价格等现况。结果:国内疾控系统BSL-3实验室中生物安全柜、气(汽)体消毒装置和压力蒸汽灭菌器的进口率高于国产率,生物安全型高效空气过滤装置国产化程度较高,各类设备的品牌呈多样化。结论:建议国家和地方管理部门加大对国产产品的扶持力度,鼓励相关企业自主研发实验室关键生物安全防护设备,提升国内实验室设施、设备技术质量,实现由进口为主向自主保障的转变。
