基于UVS平台的四旋翼无人机飞行控制方法研究

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Abstract

The quadrotor unmanned aerial vehicle has gained popularity in military and civilian fields in recent years due to its advantages such as simple structure, high maneuverability and low production cost.However,because of the characteristics of non-linearity,strong coupling,multivariable and underactuated, the research difficulty is greatly increased.This thesis focuses on the controller design of quadrotor UAV based on QBall2of UVS platform.The main contents of this research include the following aspects:

1.Establishment of a mathematical model for QBall2quadrotor UAV.The structural characteristics and flight mechanism of QBall2were introduced.Based on the inertial coordinate system and the body coordinate system,the nonlinear mathematical of the quadrotor UAV was deduced.

2.Integral backstepping sliding mode controller design.According to the semi-coupling characteristic of QBall2quadrotor UAV,a double closed-loop control structure with the attitude loop as the inner loop and the position loop as the outer loop was designed.The controller was designed based on the nonlinear algorithm-backstepping method.Considering the existence of external environmental disturbance and system parameters perturbation in the flight process of the quadrotor UAV,the sliding mode control with strong anti-interference ability was integrated into it to enhance the robustness of the system.At the same time,the integration step was introduced to reduce the state error and adjustment time.Eventually,a backstepping sliding mode controller with an integral step was designed.Two sets of comparative simulation experiments verify that the integral backstepping sliding mode controller is superior to the backstepping controller and traditional backstepping sliding mode controller.

3.Controller design based on ESO and integral backstepping sliding mode method.For the problems of strong compound disturbance and uncertainties in system modeling,the integral backstepping sliding mode controller cannot complete the accurately tracking task,adding an extended state observer(ESO). Eventually,a robust controller was designed based on ESO and integral

西南科技大学硕士研究生学位论文第V页backstepping sliding mode algorithms.The total disturbance of the system was estimated in real-time through ESO and compensated in the control volume, thereby enhancing the system's anti-jamming capability.Two sets of contrast simulation experiments with fixed-point hovering and trajectory tracking verify the effectiveness of the control strategy.

4.Semi-physical verification based on UVS platform.The system composition of UVS platform was introduced and a semi-physical comparison simulation experiment based on it was completed.Strong anti-jamming capability of the controller was verified,and the tracking performance of position and attitude angles was analyzed.

Key words:quadrotor UAV;backstepping;sliding mode;extended state observer;semi-physical verification

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1绪论 (1)

1.1课题研究背景和意义 (1)

1.2四旋翼无人机研究现状 (2)

1.3四旋翼无人机控制算法研究现状 (5)

1.4论文内容与结构安排 (8)

2QBALL2四旋翼无人机飞行原理与数学建模 (10)

2.1QBALL2机体结构 (10)

2.2飞行原理 (10)

2.3QBALL2数学建模 (11)

2.3.1地面坐标系与机体坐标系 (12)

2.3.2机体坐标系与地面坐标系的转换 (12)

2.3.3QBall2数学模型 (13)

2.4小结 (17)

3积分型反步滑模控制器设计 (18)

3.1反步法控制 (18)

3.2滑模控制 (19)

3.2.1滑动模态 (20)

3.2.2滑模变结构控制的基本问题 (20)

3.2.3滑动模态的存在条件 (21)

3.2.4滑动模态的到达条件 (21)

3.2.5滑模变结构的优缺点 (21)

3.3控制结构设计 (22)

3.4基于反步滑模法的控制器设计 (22)

3.4.1姿态环（内环）控制器设计 (23)

3.4.2位置环（外环）控制器设计 (25)

3.4.3非线性约束条件 (27)

3.5积分型反步滑模控制器设计 (27)

3.5.1姿态环(内环)控制器设计 (27)

3.5.2位置环（外环）控制器设计 (29)

西南科技大学硕士研究生学位论文第VII页

3.6控制器对比仿真实验 (32)

3.6.1小干扰情况（0.05sint） (32)

3.6.2强干扰情况（2sint） (36)

3.7小结 (37)

4基于ESO和积分型反步滑模法的控制器设计 (38)

4.1扩张状态观测器（ESO） (38)

4.2基于ESO和积分型反步滑模法的控制器设计 (39)

4.2.1基于ESO的复合干扰估计 (39)

4.2.2积分型反步滑模控制器设计 (42)

4.3控制器对比仿真实验 (45)

4.3.1定点悬停 (45)

4.3.2螺旋上升 (49)

4.4小结 (54)

5基于UVS平台的半实物验证与分析 (55)

5.1UVS平台系统组成 (55)

5.1.1QBall2 (55)

5.1.2PC主机 (57)

5.1.3无线通信 (57)

5.1.4OptiTrack定位系统 (57)

5.1.5QUARC软件 (58)

5.2半实物仿真对比实验 (58)

5.2.1积分型反步滑模法半实物仿真 (59)

5.2.2ESO和积分型反步滑模法半实物仿真 (61)

5.3小结 (64)

结论 (65)

1.工作总结 (65)

2.进一步的工作和研究展望 (66)

致谢 (67)

参考文献 (68)

攻读硕士学位期间发表的学术论文及研究成果 (72)

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1绪论

1.1课题研究背景和意义

无人机（UAV）是一种可自主导航飞行或地面操作人员通过无线电设备引导其飞行的飞机。与有人驾驶飞机相比，无人机往往更适合那些太“愚钝、肮脏或危险”的任务。无人机技术发展较早，早在一百多年前，也就是1914年第一次世界大战时，美国就已成功地将无人机运用到其军事作战中[1]。根据无人机的构造结构、机翼外形等特点，可将其分为固定翼式无人机和旋翼式无人机两大类[2]。相比而言，固定翼起步较早，技术比较成熟和完善，而旋翼则发展较为缓慢。但随着新型材料、MEMS技术以及飞控技术的发展，旋翼式无人机技术得到了迅猛发展[3]。

旋翼式无人机中最常见的当属四旋翼无人机，它呈刚性“十”字对称结构且由4个旋翼组成[4-5]。为了使附加的旋转力矩得以消除，通过让四旋翼邻翼之间的旋转方向不同，这样除了不需要单独使用尾翼来实现平衡外，还具有更简单可靠的结构和灵活的操作性。通过调节4个电机的转速产生不同的升力，从而影响四旋翼无人机姿态和位置的变化。由于其具有相对简单的结构、生产成本较低以及良好的机动性能，既而在诸多领域都备受青睐[6]。在军用领域方面，四旋翼无人机可进行军事侦察、炮兵校准等任务；在民用领域方面，微小型四旋翼可用于电力电缆巡检、动车轨道检测、精细农业等任务；在商业领域方面，四旋翼无人机通常是作为一种载体，如高空航拍、快递运输等。由此可见，四旋翼无人机在各个领域都得到广泛地使用。

对四旋翼无人机的研究意义重大，具体表现在以下几个方面：首先，四旋翼无人机是一个新兴的高科技产业，从研发、制造到使用及服务涉及诸多领域，因此四旋翼无人机的研究为各行各业的发展提供了一个契机；其次，由四旋翼无人机的数学模型可知，其具有欠驱动、半耦合、多变量、非线性等特点，并且在实际飞行过程中存在外界环境干扰和建模不确定性等问题，因此对四旋翼无人机稳定地控制也是当今的一个研究热点；最后，四旋翼无人机的广泛使用，使人们的生活更加得方便与智能。

如今，四旋翼无人机的飞控设计方面仍有许多待攻克的疑难问题：首先，由于四旋翼无人机的空气动力学难以用数学语言描述，无法对其进行精确地建模；其次，四旋翼具有欠驱动、半耦合、多变量、静不稳等特点[7]，以及在实际飞行过程中存在外界环境干扰和系统参数摄动等问题；最后，由于四