【作者】 王宇；

【导师】 张起勋；

【作者基本信息】 吉林大学 ， 机械硕士（专业学位）， 2024， 硕士

【摘要】 为适应不同应用领域中复杂的飞行环境,将可重构技术引入到无人机领域,拓展了无人机的应用场景,例如:货物运输、狭窄空间勘探和异地表面栖息等。目前可重构无人机改变构型需要附加驱动单元,增加了机身重量和机械系统复杂度,导致可靠性降低和续航能力下降。针对现有无人机续航时间短、任务能力局限等问题,本文设计了一种基于双稳态铰链的可重构无人机,依靠旋翼反扭矩驱动实现多种构型,具体内容如下:首先,提出了可重构多旋翼无人机的双稳态铰链,并验证了铰链双稳态特性。机身单元之间通过双稳态铰链联接,构建了可重构多旋翼无人机的整体结构,能够灵活实现五种不同机身构型的快速切换。更换角度限制块,可定制联接任意数量机身单元,形成可重构多旋翼无人机。其次,提出了环形机身分别与“一”字形机身、“V”形机身间的构型转换方法。这一过程是由旋翼反扭矩驱动,无需额外添加驱动单元,简化了系统结构。采用串级PID控制方法,设计了无人机姿态和位置控制器,并利用仿真实验验证了该算法的有效性。最后,搭建了实验测试系统,优化铰链参数。当采用弹性系数为0.035N/mm、预拉伸量为32.04 mm的弹性拉索时,双稳态铰链可在0.6 s内完成“L”型与直线型间的构型转换。采用上述弹性拉索制作了无人机样机,对于无人机任务能力进行了实验测试。无人机分别在0.25、0.22油门指令下,于1.4 s内便可完成由环形向“一”字形机身与逆向转换。当固定两组机身单元时,无人机由环形到“V”字形机身与逆向过程的最小油门和构型转换时间分别为0.27、0.18和0.501 s、0.467 s。此外,实验验证了“V”形机身构型下的样机具有杆状物上“栖息”与“依托悬停”的能力。论文设计了机身单元的联接关节,实现了可重构无人机的五种不同机身构型和机身单元数量的定制化。验证了通过旋翼反扭矩改变机身构型的可行性。无人机具备了抓取物体和在杆状物上“栖息”、“依托悬停”的能力,延长了续航时间,拓展了无人机的应用场景。更多还原

【Abstract】 In order to adapt to complex flight environments in different application areas,reconfigurable technology has been introduced into the field of UAVs,expanding the application scenarios of UAVs,such as cargo transportation,narrow-space exploration,and off-site surface habitats.Currently,reconfigurable UAVs require additional drive units to change their configuration,which increases the weight of the airframe and the complexity of the mechanical system,leading to lower reliability and reduced endurance.Aiming at the problems of short endurance and mission capability limitation of existing UAVs,this paper designs a reconfigurable UAV based on bistable hinge,which relies on rotor anti-torque drive to realize multiple configurations,as follows:First,a bistable hinge for a reconfigurable multi-rotor UAV is proposed,and the bistable characteristics of the hinge are verified.The fuselage units are coupled with each other by the bistable hinge to construct the overall structure of the reconfigurable multi-rotor UAV,which can flexibly realize the rapid switching of five different fuselage configurations.By replacing the angle limiting blocks,any number of fuselage units can be customized to form a reconfigurable multi-rotor UAV.Secondly,a configuration conversion method is proposed between the ring-shaped fuselage and the "I" and "V" fuselages,respectively.This process is driven by the propeller counter-torque,which simplifies the system structure by eliminating the need for an additional drive unit.The UAV attitude and position controllers are designed by using the serial PID control method,and the effectiveness of the algorithm is verified by using simulation experiments.Finally,an experimental test system was built to optimize the hinge parameters.When using an elastic cable with an elasticity coefficient of 0.035 N/mm and a prestretching amount of 32.04 mm,the bistable hinge can complete the configuration transition between the "L" type and the linear type in 0.6 s.The bistable hinge can be optimized by using the elastic cable with an elasticity coefficient of 0.035 N/mm and a pre-stretching amount of 32.04 mm.A UAV prototype was fabricated using the above elastic cable,and the UAV mission capability was tested experimentally.The UAV was able to complete the conversion from a ring-shaped to a "I" shape fuselage and the reverse direction within 1.4 s under 0.25 and 0.22 throttle commands,respectively.When two groups of fuselage units are fixed,the minimum throttle and configuration conversion times of the UAV from ring to "V" fuselage and reverse process are 0.27,0.18 and 0.501 s,0.467 s,respectively.In addition,the experiments verified that the prototype can be converted from "V" fuselage configuration to "V" fuselage configuration within 1.4 s.In addition,it is verified that the prototype with "V" fuselage configuration has the ability of "perching" and "hovering" on a pole.The paper designed the coupling joints of the fuselage units to realize the customization of five different fuselage configurations and the number of fuselage units of the reconfigurable UAV.The feasibility of changing the fuselage configuration by rotor counter torque is verified.The UAV has the ability to grab objects,"perch" on poles and "hover",which prolongs the endurance and expands the application scenarios of the UAV.更多还原