中文说明：
四旋翼无人机是一种具有六个自由度和四个输入的欠驱动强耦合、外型新颖结构简单的飞行器。由于其具有制造成本地、重量轻、体积小、操作简单、使用方便、隐身性好、对作战环境要求低的特点，使其能准确、高效的执行各种军事或民用任务，因此四旋翼无人机具有一定的军事和民用价值。本课题针对四旋翼无人机的特点和飞行原理，对其动力学分析以及运动控制的研究，利用牛顿—欧拉方程，建立了四旋翼无人机的动力学模型,并针对该模型设计了PID四通道控制系统,且在Matlab/Simulink仿真平台上,利用PID控制系统对四旋翼无人机进行仿真，完成了对四旋翼无人机运动控制和与地面运动物体的交会，仿真结果表明：仅仅通过改变四只旋翼的转速来改变升力，进而改变四旋翼无人机的姿态控制和位置控制，从而实现了四旋翼无人机的运动控制以及与地面运动物体的交会。(Height Control of Four-Rotor Aircraft)
English Description：
Four rotor unmanned aerial vehicle (uav) is one kind has six degrees of freedom and four input of underactuated strong coupling, novel appearance simple structure of the aircraft.Due to its manufacturing cost, light weight, small volume, simple operation, easy to use, good invisibility and the characteristic of low requirement to the operational environment, can make the accurate and efficient perform a variety of military or civilian tasks, so the four rotor unmanned aerial vehicle (uav) has certain value in military and civilian.This topic according to the characteristics of the four rotor unmanned aerial vehicle (uav) and flight principle, the study of the dynamic analysis and motion control, using the Newton - euler equation, set up four rotor dynamics model of unmanned aerial vehicle (uav), four channel according to the model design of the PID control system, and in the Matlab/Simulink platform, four rotor unmanned aerial vehicle (uav) to make use of PID control system simulation, motion control and completed on four rotor unmanned aerial vehicle and ground motion object intersection, the simulation results show that only by changing the four rotor speed to change the lift, and then change the four rotor uav attitude control and position control, so as to realize the motion control of the four rotor unmanned aerial vehicle (uav) and the SEC with ground motion object.(Height Control of Four - Rotor Aircraft)