【作者】 张健；

【导师】 吴了泥；

【作者基本信息】 厦门大学 ， 航空工程， 2018， 硕士

【摘要】 复合翼垂直起降无人机结构简单、成本低,同时兼具旋翼无人机可垂直起降和固定翼无人机续航时间长的优势,具有广泛的应用前景。石油管道巡线、森林防火等领域对复合翼垂直起降无人机的需求日益迫切,但复合翼垂直起降无人机的飞行控制技术仍缺少相关研究。本文以某型复合翼垂直起降无人机为背景,对复合翼垂直起降无人机飞行控制技术进行研究。本文主要工作及成果如下。首先,分析了复合翼典型飞行剖面,定义了复合翼的三种典型飞行模态:固定翼模态、多旋翼模态和过渡模态;根据质量数据和气动数据分别建立了这三种飞行模态下六自由度数学模型;进一步开展操稳特性分析。其次,根据飞行任务设计复合翼飞行控制系统,对复合翼飞行控制系统的传感器、执行机构、飞行控制计算机进行硬件选型,对飞行控制系统软件的导航模块、控制律解算模块、飞行模态转换模块和遥控遥测模块进行设计。再次,对复合翼无人机的固定翼模态和多旋翼模态进行控制律设计。固定翼模态控制律设计了俯仰角控制、滚转角控制、高度控制、航迹控制;多旋翼模态控制律设计了位置控制、高度控制、航向控制、舵面分配算法。再再次,对复合翼无人机模态转换的各个阶段进行详细分析并采取相应的策略。旋翼转固定翼的加速段有个较大抬头趋势,采用升降舵前馈对其进行控制;对旋翼控制结构和固定翼控制结构之间的切换,设计权值转换方案;旋翼停止过程存在较大干扰,采用的增强固定翼控制增益来提高姿态控制能力;固定翼转多旋翼的减速段设计速度控制减速策略,使减速过程变得平缓。由于模态转换段模型不准确,为降低风险,本文设计了循序渐进的模态转换滑行实验方案。最后,根据复合翼垂直起降无人机海上应用需求,设计复合翼舰载移动着陆控制策略。舰载移动着陆过程规划进场航迹捕获段、移动轨迹下滑段、模态转换段、侧向调整段四个子阶段,分别设计制导与控制策略。开展陆上模拟着陆实验,验证了控制策略的可行性。更多还原

【Abstract】 VTOL,short for composite wing vertical take-off and landing uav,can be made of simple structure at low cost.At the same time,it can take off and land vertically without runway and fly fast and hover in midair.Therefore,it can be applied widely in industries fields.There is an increasing demand for VTOL,but the control technology of VTOL is lack of research at present.The thesis carries out the research on the control technology of VTOL in the above background.The major work is as follows.Firstly,the thesis describes the typical flight profile of VTOL and divides the flight modes of VTOL into three modes:fixed-wing mode,multi-rotors mode and transition mode.Then the thesis builds 6-DOF rigid body dynamic mathematical models for these three modes according to mass data and aerodynamic data,and the thesis analyzes the aerodynamic characteristics and the modal characteristics.Secondly,the thesis designs flight control system of VTOL.The thesis chooses the hardware for sensor,actuator,and flight control computer.And the thesis explains how to design software.Thirdly,the thesis designs the control law of VTOL in both fixed-wing mode and multi-rotors mode.In the fixed-wing mode,the thesis designs pitch control system,roll control system,height control system,and flight path control system.In the multi-rotors mode,the thesis designs position control system,height control system,course control system,and actuator allocation algorithm.Fourthly,the thesis analyzes the phases in transition mode in detail and designs the control strategies.There’s a big uptrend during transition from the multi-rotors mode to the fixed-wing mode,so we take the strategy of elevator feedforward control.And the thesis designs the weight transition scheme for the switchover between the control structure of multi-rotors and that of fixed-wing.There’s a big disturbance when the rotor is decreasing,so we take the enhanced control gain.During the transition from fixed-wing mode to the multi-rotors mode,we take the speed command control strategy to make the change of attitude gradual.Due to uncertainty of mathematical model in transition mode,we design a transition experiment to verify control strategy step by step.Finally,with the requirements of shore applications,the thesis designs the control strategy for VTOL to land on a ship on the sea.The control strategy is designed directing at different phases,and the flight experiment is carried out to verify the designed strategy.Then,we analyze the results of the experiment,and the results proved that the control scheme designed is feasible.更多还原