四旋翼飞行器自适应反演姿态控制器设计

针对四旋翼飞行器的非线性、强耦合控制问题,提出了一种自适应反演控制器设计方法。通过引入一阶低通滤波器来获取虚拟控制量的一阶导数,避免了虚拟控制量的复杂求导计算。采用充分光滑的投影算子对模型非匹配不确定项进行估计和补偿,放宽了传统投影算子对已知不确定项的上、下界的要求,同时抑制了“参数漂移”。仿真结果表明,该控制器具有良好的控制效果和鲁棒性。     

四旋翼无人机飞行姿态模型参考自适应控制

四旋翼无人机具有机械结构简单、可垂直起降等优势,在各个领域都有极广泛的应用.经典控制算法如PID对无人机在受扰动或环境变化时的控制效果不理想,难以调节至平衡状态.论文对动力学建模加以适当简化,设计了自适应控制律,数值仿真实验结果表明,模型参考自适应控制能在很大范围内有效屏蔽干扰,验证该算法是有效的.     

四旋翼无人机自适应导航控制

研究四旋翼(Quadrotor)无人机导航控制问题。针对传统的四旋翼无人机导航控制方法的目标定位误差和实时性差问题,提出了基于CLOS技术的导航控制方法。采用CLOS技术所开发的导航控制系统使得四旋翼无人机能够在移动停机坪完成自主导航和着陆的任务,并详细研究了导航控制系统的设计和仿真。仿真结果显示了所设计的导航控制系统的性能和有效性,可应用于四旋翼无人机的实时导航。     

无人机航迹跟踪控制与仿真

对于无人机的精确航迹跟踪问题进行了研究。系统分为基本姿态控制器设计和制导系统设计两个部分进行研究。利用多重时间尺度奇异摄动理论,结合非线性动态逆方法设计了基本姿态控制器,包括快逆回路和慢逆回路两部分。由引导飞机沿期望航迹的指令加速度解算出跟踪指令航迹所需要的制导力,求出飞机改变姿态所需的控制指令,作为基本姿态控制器的输入。针对某无人机模型进行了机动航迹跟踪仿真验证,仿真结果显示系统能够较好的跟踪指令机动航迹。证明了该方法的有效性和实用性。     

四旋翼无人机鲁棒自适应姿态控制

 四旋翼无人机的姿态控制是自主飞行控制的核心,针对四旋翼姿态易受外界环境干扰和内部参数摄动等不确定性影响的问题,设计了一种鲁棒自适应反步控制器,以提高四旋翼的鲁棒性。建立了四旋翼完整的姿态运动模型,并将其转化为含有广义不确定性的多输入多输出非线性系统。根据该系统满足严格反馈的结构特点,设计了反步控制器; 针对系统中存在的外部干扰和内部参数摄动等不确定性,引入了一类鲁棒自适应函数来抵消该不确定性对系统的影响; 采用非线性跟踪微分器估计虚拟控制量的微分信号,减小了反步控制器设计中普遍存在的“计算膨胀”问题; 通过构造Lyapunov 函数证明闭环系统是稳定且指数收敛的。仿真结果表明,所设计控制器具有良好的控制效果和鲁棒性。     

Bounded‐Input Control of the Quadrotor Unmanned Aerial Vehicle: A Vision‐Based Approach

In this paper, a bounded‐input controller is designed for the quadrotor vertical take‐off and landing unmanned aerial vehicle (UAV). Visual information is used to localize the aircraft with respect to its environment and an image‐based visual servo scheme is developed to navigate the motion of it. The visual features are selected from perspective image moments and projected on a rotated image plane, which simplifies the controller design. The flow of the features is used as the linear velocity information, and the controller assumes angular velocity and attitude information available for feedback. To design the controller, the dynamics of the quadrotor are decoupled into two parts: translational dynamics and rotational dynamics. First visual data are used to design a bounded‐input controller for the translational dynamics, and then a saturated controller is designed for the rotational dynamics. The boundedness of the controller increases the chance of keeping the visual features in the field of view of the camera. Furthermore, the controllers also cope with the unknown depth of the image, and the external disturbances. The complete stability analysis of the overall system is presented to show that all states are bounded and the error signals converge to zero asymptotically. Simulation examples are provided in both nominal and perturbed conditions which show the effectiveness of the proposed theoretical results.     

基于神经网络的无人机姿态自适应控制仿真

针对四旋翼无人机姿态控制中模型不完整、部分参数和扰动不确定的问题,提出了一种基于神经网络的自适应控制方法,采用RBF神经网络对无人机姿态动力学模型中不确定和扰动部分进行学习,设计了以类反步法为基础,包含反馈控制和神经网络控制的自适应控制器,实现了对未知动态的准确逼近,解决了传统控制方法中过于依赖精确模型的问题。同时设计了神经网络的权值自适应律,实现了控制过程中的在线学习和调整,并且通过李雅普诺夫方法证明了闭环系统的稳定性。仿真结果表明,在存在较大扰动的情况下,上述控制器可得到很好的控制效果,可以实现误差的快速收敛,具有较好的鲁棒性和自适应性。     

Nonlinear Robust Tracking Control of a Quadrotor UAV on SE(3)

This paper provides nonlinear tracking control systems for a quadrotor unmanned aerial vehicle (UAV) that are robust to bounded uncertainties. A mathematical model of a quadrotor UAV is defined on the special Euclidean group, and nonlinear output‐tracking controllers are developed to follow (i) an attitude command, and (ii) a position command for the vehicle center of mass. The controlled system has the desirable properties that the tracking errors are uniformly ultimately bounded, and the size of the ultimate bound can be reduced arbitrarily by control system parameters. Numerical examples illustrating complex maneuvers are provided.     

四旋翼无人机轨迹跟踪的容错控制

针对四旋翼无人机轨迹跟踪的容错控制问题,提出了一个鲁棒[H∞]控制和干扰观测器与故障估计器相结合的容错复合控制器的方法。在外部有界扰动和加性故障的条件下,实现对四旋翼无人机的轨迹跟踪。将四旋翼无人机非线性动态模型解耦成独立的外环位置控制系统和内环角度控制系统,引入区间矩阵对系统参数进行描述,使用干扰观测器和故障估计器进行干扰和故障的估计和补偿。然后设计一个复合控制器既能更好地抑制干扰又能保证无人机在自身存在故障的情况下平稳飞行。通过仿真证明该方法的有效性。     

基于故障程度的四旋翼无人机容错控制

针对四旋翼无人机执行机构部分失效故障,采用一组线性二次最优控制器,并且设计了可变因子二阶卡尔曼滤波器在线快速估计状态和检测故障。当故障被检测和诊断出来时,通过可变因子二阶卡尔曼滤波器调节,同时切换到相应的线性二次最优控制器使故障影响变小。最后,在Matlab实验平台上对所提方法的可行性和有效性进行仿真验证验证,结果表明四旋翼无人机执行机构在发生部分失效故障时,输出信号能够快速跟踪轨迹,实现了对执行机构部分失效故障的容错控制。     

微小型四旋翼无人飞行器姿态控制

关于自主研发的微小型四旋翼无人飞行器姿态控制问题,针对姿态控制要求的稳定性,根据飞行器的飞行原理,通过数学推导建立近似的姿态角线性模型.操作飞行器飞行并采集相关飞行数据在MATLAB中辨识出有效的模型参数并验证模型准确性.在姿态角模型的基础上,分别设计了ALQR控制器以及卡尔曼滤波器.飞行实验结果表明,设计的卡尔曼滤波器具有很好的滤波效果和状态量推测性能,设计的ALQR控制器能较好的解决控制指令跟踪的问题,满足姿态优化控制的要求.     

The Trajectory Tracking Problem of Quadrotor UAV: Global Stability Analysis and Control Design Based on the Cascade Theory

This paper deals with the trajectory tracking problem of a six‐degree of freedom (6‐DOF) quadrotor unmanned aerial vehicle (UAV). The problem of simplified kinematics based on Euler angles is analyzed and the modified Rodrigues parameters (MRPs) technique is introduced to model the rotational dynamics of the rigid body. A nonlinear system error model is established based on the trajectory tracking problem, and, due to the coupling property between the translational and rotational dynamics, we divide the complete closed‐loop system into two reduced‐order subsystems and a coupling term. The Rodrigues theorem is applied to analyze the internal connections between the coupling term and MRPs. Therefore, the global stability conclusions, by which the trajectory tracking controller of the quadrotor UAV could be designed based on the subsystem directly in future works, are proved based on several assumptions of the subsystems. Thereafter, the controllers, using the backstepping approach and nonlinear disturbance observer/sliding mode control approach, which stabilize the quadrotor UAV globally ‐exponentially and globally uniformly bounded, are proposed based on the stability theorem proofs mentioned above. Numerical simulations are provided to show that the theoretical conclusions and the controller proposed are effective.     

基于模糊不确定观测器的四旋翼飞行器自适应动态面轨迹跟踪控制

针对具有未知外界扰动和系统不确定性的四旋翼飞行器,提出了一种基于模糊不确定观测器（Fuzzy uncertainty observer,FUO）的自适应动态面轨迹跟踪控制方法.通过将四旋翼飞行器系统分解为位置、姿态角和角速率三个动态子系统,使得各子系统虚拟控制器能够充分考虑欠驱动约束;采用一阶低通滤波器重构虚拟控制信号及其一阶导数,实现四旋翼跟踪控制设计的迭代解耦;设计了一种模糊不确定观测器,用以估计和补偿未知外界扰动与系统不确定性,从而确保闭环系统的稳定性和跟踪误差与其他系统信号的一致有界性.仿真研究验证了所提出的控制方法的有效性和优越性.     

无人机自主智能控制系统设计研究

本文设计了无人机自主智能控制系统,并以无人机自主智能控制系统的智能定位精确度与自主飞行性能验证为例,进行了系统实验分析.结果表明,任务管理体系可基于计算机,对无人机的自主起升下降进行有效控制,并实现了多任务点之间的直线飞行,水平方向定位误差可控制0.14m以内;既可保障飞行稳定性,又可保持飞行高度,垂直误差可控制在0....     

基于鲁棒自适应的无人直升机悬停控制

小型无人直升机凭借良好的机动特性,在军事和民用方面有着广泛的用途。针对小型无人直升机悬停模型,考虑模型参数不确定对无人机控制的影响,提出一种鲁棒自适应控制律,实现无人机控制系统对不确定扰动的抑制。首先,基于无人直升机线性化悬停模型设计滑模面,并结合标称系统控制的反馈增益,获得滑模面的设计参数;在此基础上,利用传统滑模趋近律设计方法设计控制器;为改善系统控制性能,设计基于自适应增益的趋近律,实现系统鲁棒自适应控制。其次,利用Lyapunov稳定理论对所设计的鲁棒自适应控制策略的稳定性进行分析说明。最后,通过与基于指数趋近律以及变速趋近律的两种滑模控制方法仿真对比,验证了所设计的控制方法的有效性和优越性。     

Adaptive Nonlinear Stabilization Control for a Quadrotor UAV: Theory, Simulation and Experimentation

In this paper an adaptive control scheme along with its simulation, and its implementation on a quadrotor are presented. Parametric and non- parametric uncertainties in the quadrotor model make it difficult to design a controller that works properly in various conditions during flight time. Decentralized adaptive controller, which is synthesized based on improved Lyapunov-based Model Reference Adaptive Control (MRAC) technique, is suggested to solve the problem. The proposed control scheme does not need knowing the value of any physical parameter for generating appropriate control signals, and retuning the controller is not required for different payloads. An accurate simulation that includes empirical dynamic model of battery, sensors, and actuators is performed to validate the stability of the closed loop system. The simulation study simplifies implementation of the controller on our real quadrotor. A practical algorithm is proposed to alleviate and accelerate the tuning of controller parameters. The controller is implemented on the quadrotor to stabilize its attitude and altitude. Simulation and experimental results demonstrate the efficiency and robustness of the proposed controller.     

四旋翼无人机时延模糊自抗扰容错控制

针对四旋翼无人机系统执行器故障问题,为改善飞行控制系统性能,提出一种时延模糊自抗扰容错控制。首先,根据四旋翼无人机系统非线性数学模型和执行器故障模型,选择模糊自抗扰控制器作为基准控制器,在未发生执行器故障的情况下,使飞行控制系统保持稳定;其次,在发生执行器故障的情况下,利用时延控制技术估计故障信息,并与模糊自抗扰控制相结合,实现容错控制;最后,对所研究的容错控制算法进行数值仿真分析,仿真结果表明:把时延控制与模糊自抗扰控制相结合,能有效调节执行器故障,使飞行控制系统对故障产生的干扰具有良好的鲁棒性。     

基于广播内存网络的无人机飞控实时仿真系统

该文提出了一种基于广播内存网络的无人机飞行控制实时仿真系统的设计与实现,文中阐述了广播内存网络的功能特点,它能实现网络中点对点、点对多点的实时通信。系统硬件平台采用了基于网络的多机分布式体系结构。系统软件采用了YC 6．0设计语言。该系统能够模拟无人机动力学、运动学特性,输出机载传感器信号,具有实时性高、可靠性高、性能价格比高、扩展性好的特点。实际使用结果表明系统性能良好,完全满足飞行控制系统半物理实时仿真试验的要求。     

Design of Fractional‐Order Backstepping Sliding Mode Control for Quadrotor UAV

This paper derives a nonlinear translational and rotational dynamic model of the quadrotor UAV. An original fractional‐order backstepping sliding mode control method for a typical quadrotor UAV is presented. The new approach can decrease the chattering phenomenon and increase the robustness of control strategy. The strongly coupled characteristics of the under‐actuated system are sought by the virtual controllers. The feasibility for different track trajectories are verified using MATLAB. The new control method can not only track the expected trajectory very well but also has a better robustness for different complex trajectory under disturbances, as the simulation results demonstrate.     

飞翼无人机着陆过程中的抗侧风控制研究

飞翼布局无人机的无尾布局给横侧向的稳定与控制带来困难,尤其是下降阶段有侧风时的航迹控制.带侧滑保持航向和带偏流保持航向是常用的两种抗侧风策略,为解决稳定性控制,研究了两种策略的优缺点,并针对两种控制策略分别设计了横航向抗侧风控制器.结合飞翼布局无人机的特点,在着陆过程中的不同阶段选择不同的抗侧风策略,在进场和下滑初始阶段采用带偏流保持航向方式,在下滑到一定高度时转为带侧滑保持航向的控制策略.仿真结果表明,选择的控制策略以及设计的控制器合理、可行,满足飞翼无人机着陆阶段的抗侧风要求.