摘 要

无人驾驶飞机，简称无人机，是指通过远程遥控控制或者靠自身携带的传感器自主飞行的无人驾驶飞行器。无人飞行器根据机翼类型可分为固定翼飞行器和旋翼飞行器。其中旋翼飞行器中的四旋翼飞行器，具有结构简单、能够垂直起降、制造成本较低等特点。随着科技水平的进步，四旋翼无人机的发展已经取得了很大的进步，现已被广泛应用于航拍、交通监控、空气污染检测、森林防火、低空侦查、救援等民事和军事领域。

本文首先分析了四旋翼无人机的研究背景以及国内外的研究现状，并对四旋翼无人机的结构形式和飞行原理进行研究。随后又介绍了四旋翼无人机飞行姿态的计算方法，描述了地理坐标系和机体坐标系，以及欧拉角与四元数之间的转换关系。

其次，介绍了四旋翼无人机控制系统的硬件设计，主要包括器件选型和各模块电路设计两个部分。飞行控制系统采用STC15W4K48S4作为主控制器，负责分析处理数据；惯性测量单元则采用MPU6050六轴传感器，用于对机体姿态信息的检测；采用场效应管驱动电路来驱动空心杯电机，通过NRF24L01无线模块与遥控器进行通信。

最后，在经典PID控制算法的基础上，本文采用串级PID控制算法设计了四旋翼飞行器的飞行控制系统的软件部分。并且通过多次试验，整定PID参数，实现了平稳飞行。

关键词：四旋翼无人机；姿态控制；飞行控制系统；串级PID控制

Design of Control System for Electric Unmanned Aerial Vehicle

ABSTRACT

Unmanned Aerial Vehicle, referred to UAV, which is controlled by remote control or by a self-contained sensor. Unmanned aircraft can be divided into fixed-wing aircraft and rotorcraft according to the wing type. The quadrotor in the rotorcraft has the advantages of simple structure, vertical take-off and landing, lower manufacturing cost. With the development of science and technology, a quadrotor has made great progress and has been widely used in civilian and military fields including aerial photography, traffic monitoring, air pollution detection, forest fire prevention, low altitude investigation and rescue.

Firstly, this thesis describes the quadrotor’s background and current research status at home and abroad, then introduces the quadrotor’s structure and flight principle. Then it introduces the flight attitude representation of the quadrotor, and describes the geographical coordinate system and the body coordinate system. At the same time, it introduces the relationship between Enler angle and quaternion.

Secondly, this thesis introduces the hardware design of the quadrotor’s flight system. The STC15W4K48S4 was applied as the main controller to analyze and process data, and sensor modules like MPU-6050 were mainly used for detecting gestures and other information, MOSFET circuit was capitalized on driving the coreless motors. In addition, the flight control system communicates with the remote control by the NRF24L01 wireless module.

Finally, based on the classical PID control algorithm, this thesis uses the cascade PID control algorithm to design the software part of the flight control system of the quadrotor. And through several tests, I set the PID parameters, to achieve a smooth flight.

Key words: quadrotor; attitude control; flight control system; cascade PID control

目 录

摘 要 I

ABSTRACT II

第1章 绪论 - 1 -

1.1 研究背景及意义 - 1 -

1.2 国内外研究现状 - 2 -

1.3本文的研究内容 - 5 -

第2章 四旋翼无人机的总体设计 - 6 -

2.1 四旋翼无人机的机理分析 - 6 -

2.1.1 四旋翼无人机的结构形式 - 6 -

2.1.2 四旋翼无人机的飞行原理 - 6 -

2.2 四旋翼无人机飞行姿态的表示 - 9 -

2.2.1 坐标系定义 - 9 -

4.1.2 姿态角定义 - 10 -

4.1.3 欧拉角介绍 - 10 -

4.1.4 四元数介绍 - 11 -

第3章 四旋翼无人机控制系统硬件设计与实现 - 13 -

3.1 总体设计 - 13 -

3.2 主要器件选型 - 13 -

3.2.1 飞控微处理器芯片 - 13 -

3.2.2 惯性测量单元芯片 - 14 -

3.3 各模块电路设计 - 15 -

3.3.1 STC15W4K48S4主控模块 - 15 -

3.3.2 MPU6050六轴惯性测量单元 - 16 -

3.3.3 5v升压和3.3v降压稳压电源模块 - 17 -

3.3.4 PWM电机控制模块 - 18 -

3.3.5 NRF24L01无线通讯模块 - 20 -

第4章 四旋翼无人机控制系统软件设计与实现 - 22 -

4.1 软件总体设计 - 22 -

4.1.1 Keil开发工具简介 - 22 -

4.1.2 系统程序结构设计 - 22 -

4.2 姿态测量传感器任务设计 - 24 -

4.3无线通讯任务设计 - 25 -

4.4 基于PID的飞行控制系统软件设计 - 26 -

4.4.1 经典PID控制算法介绍 - 26 -

4.4.2 数字PID控制器 - 28 -

4.4.3 基于串级PID算法的控制系统设计 - 28 -

4.4.4 PID参数整定 - 29 -

总结与展望 - 31 -

致 谢 - 32 -

参考文献 - 33 -

附录A 实物图 - 34 -