基于模糊算法的四旋翼飞行器高度锁定研究

发布时间：2018-02-19 21:07

本文关键词： 四旋翼飞行器高度锁定模糊控制梯度下降法　出处：《西安科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：四旋翼飞行器以其低成本、小尺寸、机动灵活、易于操作等优点在近几年得到了广泛的应用,无论是在军事、民用以及娱乐等众多场合都能见到其身影。随着四旋翼飞行器的广泛应用,吸引了越来越多的飞行器爱好者对其研究,但由于其具有非线性、强耦合、结构复杂等特点,难以建立精确的数学模型对其进行精确稳定的控制,国内外学者针对其不同的控制目的,也提出了许多具有针对性的控制算法,并取得了一定的成果。本文主要针对四旋翼飞行器的高度锁定进行控制,提出了基于模糊控制算法的四旋翼飞行器高度锁定控制方法。通过建立模糊控制器并离线生成模糊控制规则表,实现四旋翼飞行器高度锁定的在线控制。该模糊控制器以飞行器的实际高度和实际高度与锁定高度的高度差作为模糊控制器的输入量,以飞行器油门通道的量化值作为模糊控制器的输出量,采用双输入单输出的模糊控制器结构,使用在飞行器高度锁定过程中手动操作的专家经验生成一系列语言控制规则,利用MATLAB模糊控制工具箱生成模糊控制系统,经过模拟操作后生成模糊控制系统的输入输出量,再将这些输入输出量装载进提前准备好的查询系统,最后生成经过去模糊化后的模糊控制规则表。将生成的模糊控制规则表装载进飞行器控制系统中实现在线控制。由于模糊控制在建立语言规则以及确定模糊集合隶属函数参数时的主观性,该模糊控制规则表未必能准确反映该飞行器系统的实际飞行状态,所以,论文最后利用大量的实验数据采用梯度下降法对该模糊控制系统中的隶属函数的参数进行优化,使其能准确反映该飞行器系统的实际状况。通过实验证明,经过梯度下降法优化后的隶属函数参数能更加准确的反映飞行器的飞行状况,本课题所研究的飞行器高度锁定控制取得了很好的效果。
[Abstract]:Four-rotor aircraft has been widely used in recent years with its advantages of low cost, small size, flexibility, ease of operation and so on, whether in the military, It can be seen on many occasions, such as civil and entertainment. With the wide application of four-rotor aircraft, it attracts more and more aircraft enthusiasts to study it, but because of its nonlinear, strong coupling, complex structure and so on, It is difficult to establish accurate mathematical model to control it accurately and stably. For its different control purposes, scholars at home and abroad also put forward a lot of targeted control algorithms. And some achievements have been made. This paper mainly focuses on the control of the altitude lock of the four-rotor aircraft. Based on fuzzy control algorithm, a height locking control method for four-rotor aircraft is proposed. The fuzzy controller is established and the fuzzy control rule table is generated offline. The fuzzy controller takes the actual height of the aircraft and the height difference between the actual height and the locking height as the input of the fuzzy controller. Taking the quantization of throttle passage as the output of the fuzzy controller, the fuzzy controller structure with double input and single output is adopted, and a series of language control rules are generated by using the expert experience of manual operation in the course of altitude lock of the aircraft. The fuzzy control system is generated by using the MATLAB fuzzy control toolbox, the input and output of the fuzzy control system are generated after the simulation operation, and the input and output quantities are loaded into the query system prepared in advance. Finally, the fuzzy control rule table after defuzzification is generated. The generated fuzzy control rule table is loaded into the aircraft control system to realize online control. Since fuzzy control is used to establish language rules and determine fuzzy sets. Subjectivity in membership function parameters, The fuzzy control rule table may not accurately reflect the actual flight state of the aircraft system. Therefore, the parameters of the membership function in the fuzzy control system are optimized by using a large number of experimental data using gradient descent method. The experimental results show that the membership function parameters optimized by gradient descent method can more accurately reflect the flight status of the aircraft. The aircraft altitude locking control studied in this paper has achieved good results.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：V249

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