【作者】 曾伟；

【导师】 鲜斌；

【作者基本信息】 天津大学 ， 控制科学与工程， 2012， 硕士

【摘要】 四旋翼无人机具有体积小、重量轻、机械结构简单等特点,与传统的单旋翼无人机相比,四旋翼无人机不需要尾桨来抵消反转力矩,使得四旋翼无人机电机转速低、消耗小、安全性高,因此四旋翼无人机可以在窄小的空间内飞行并且具有良好的机动性能。基于以上特点,四旋翼无人机具有广泛军用和民用价值。但是其本身所具有的模型结构复杂、易受环境影响等缺点制约了四旋翼无人机的进一步发展,因此对四旋翼无人机的研究具有十分重要的意义。在四旋翼无人机的硬件结构中,驱动器作为无人机的动力装置,直接决定着无人机的飞行效果。因此,本文针对四旋翼无人机的驱动器做了一系列研究,包括无刷电机转速的测量、无刷电机的特性建模以及无刷电机转速的控制器设计等。四旋翼无人机采用无刷直流电机作为动力装置。对无刷电机的特点和运动特性的分析,是建立在无刷电机转速测量的基础上,因此本文设计了两种无刷电机转速测量的方法:1).基于霍尔传感器的无刷电机转速测量;2).基于端电压频率的无刷电机转速测量。两种方法各有利弊,可根据不同场合选用不同的方法测量无刷电机转速。本文设计了“PC机-数字信号处理器(DSP)-电子调速器-无刷电机-霍尔传感器”的硬件装置,利用此装置采样电机的转速信息,并使用MATLAB软件和非线性回归分析,建立了无刷电机的稳态模型和动态模型,完成了无刷电机的特性建模。接下来本文设计了两种控制器来实现对无刷电机转速的实时控制,分别为开环控制器和闭环控制器。基于无刷电机稳态模型,根据给定的电机转速和电源电压,解算出控制信号PWM波占空比,实现了对无刷电机转速的开环控制;采用模糊控制结合专家系统参数自整定PID控制的方法,从而减小了无刷电机转速控制的上升时间,提高了电机的响应速度,实现了无刷电机转速的闭环控制。最后,结合四旋翼无人机驱动器的实际应用,本文设计了基于DSP的四旋翼无人机驱动电路,制作了相应的印刷电路板,并使用印刷电路板完成了四个电机转速跟踪惯性测量单元(IMU)给定信号的实验,取得了较为理想的结果。实验证明,本文设计的电机转速控制器运行稳定,能够达到了预期的控制效果。更多还原

【Abstract】 The quadrotor unmanned aerial vehicle (UAV) has a special configuration which results in better mobility, simpler structural design, and smaller comparing with other rotorcrafts. Meanwhile, the value of the quadrotor UAVs in both military use and civil use is huge, but the quadrotor has the disadvantages of complex dynamic model and environmental impact greatly which restrict its development and application, so more and more researchers have begun the research on the control quadrotor UAVs. As an important part of the quadrotor UAV systems, the actuators directly determine the quadrotor’s flying performance, so a series of research will be done about the modeling and control of the quadrotor’s actuators in this thesis.Brushless motor is often used as the actuator of quadrotor UAVs. Since the control of brushless motor might need speed measurements, so two methods of measuring motor speed which is motor speed sampling via hall sensor and terminal voltage frequency are proposed in this thesis. Both methods have its own advantages and disadvantages, which method will be used is determined by the actual implementation.A hardware architecture of computer, DSP, ESC, brushless motors and hall sensor is being designed to obtain steady state and dynamic models of the brushless motor via nonlinear regression analysis.Two controllers which are the open-loop controller and the closed-loop controller are designed for real-time motor speed control system. The open-loop control system uses steady state model which is established in the second chapter, according to motor speed and supply voltage, to calculate out the duty cycle signal of PWM wave. The closed-loop control uses fuzzy and expert PID control method to achieve brushless motor closed-loop control. This controller greatly reduces the system’s rise time, delay time, and increase the sensitivity of the brushless motor.Finally,a drive circuit is designed and two PCB boards are produced to achieve the underlying control on quadrotor UAVs. And the experiment that four brushless motors track are controlled to track the actual attitude angles obtained from the on-board IMU is completed via the two PCB boards. Through the results of these experiments, it can be concluded that the brushless motor speed control system works stably, and the desired objectives are achieved.更多还原