基于Cortex-M7微处理器核心平台的无人机飞控系统

发布时间：2018-07-20 15:44

【摘要】：近年来,关于无人飞行机器的研究已经达到了白热化的程度。各种无人机系统架构在近几年都被争相提出。作为无人机的控制核心,无人机飞控平台肩负了众多复杂且特殊的任务,如对各种传感器外设的数据采集与上传、对伺服控制器的操作,无人机飞行过程中日志记录,与地面控制站进行通信等。因此,一个功耗较低、性能足够、可靠性高的无人机飞控平台是无人机系统的重中之重。本文针对目前市面上已有的各类飞控的具体缺点,基于目前最新架构Cortex-M7的SAMV71Q21微处理器,以NUTTX嵌入式实时OS作为飞控软件平台架构的底层基础,设计了一整套无人机飞控软硬件平台。本设计旨在提供一个无人机飞控整体系统的搭载平台,因此不涉及具体算法研究以及相应模块设计。整个飞控平台可以从硬件架构和软件设计两个方面对其进行阐述。在硬件架构方面,由于要兼顾到低功耗、高性能以及接口丰富等特性的平衡统一,本文采用了ATMEL公司生产的基于Cortex-M7架构的SAMV71Q21微处理器作为飞控硬件的核心,外围接口的设计过程中则考虑到了无人机飞控平台中可能涉及到的各种接口,如RS485,I2C,SPI,CAN等,在硬件平台上都有相关接口提供。传感器模块则主要包括MTI姿态测量组件以及MS5803高精度气压计。无线通信模块方面提供SBUS接口,主要是用于接收SBUS遥控接收机信号以及输出SBUS信号,对云台进行控制及红外控制相机抓拍。同时还提供UART总线接口,用于飞控平台与地面站之间数传模块与图传模块的通信。在软件设计方面,考虑到无人机对软件平台的可靠性、实时性的需求,本文采用了基于Nuttx实时嵌入式操作系统的软件平台设计方案。该系统采用类UNIX架构,具有完整任务调度模块、文件管理系统、内存管理模块,非常适合飞控平台复杂的外设情景以及多样化任务需求。同时引入解决进程间数据传输实时性问题的微对象代理进程间通信模块,该进程间通信系统为实时通信系统,承担传感器之间或传感器与上层应用之间的信息交互。这些措施使得软件平台能够达到较好的实时性、可移植性以及可靠性。本文在完成了整套硬件平台及软件平台的搭建后,对飞控平台的硬件以及相关传感器网络、操作系统运行情况进行了验证与测试,最终验证整个飞控平台的可行性与实用性,而最后的飞行测试也证明了飞控系统能够符合项目设计需求。
[Abstract]:In recent years, the research on unmanned flying machine has reached the level of white-hot. Various UAV system architectures have been proposed in recent years. As the core of UAV control, UAV flight control platform shoulders many complicated and special tasks, such as collecting and uploading data from various sensor peripherals, operating servo controller and logging during UAV flight. Communicate with ground control station, etc. Therefore, a UAV flight control platform with low power consumption, sufficient performance and high reliability is the most important part of UAV system. Aiming at the specific shortcomings of all kinds of flight control in the market at present, based on the SAMV71Q21 microprocessor of Cortex-M7, this paper takes the NUTTX embedded real-time OS as the underlying foundation of the flight control software platform architecture. A set of UAV flight control software and hardware platform is designed. The purpose of this design is to provide a platform for UAV flight control system, so it does not involve the specific algorithm research and the corresponding module design. The whole flight control platform can be described from hardware architecture and software design. In the aspect of hardware architecture, due to the balance and unity of low power consumption, high performance and rich interface, this paper adopts SAMV71Q21 microprocessor based on Cortex-M7 architecture produced by Atmel Company as the core of flight control hardware. In the design process of peripheral interface, all kinds of interfaces that may be involved in UAV flight control platform, such as RS485C2CU SPIcan and so on, are provided on hardware platform. The sensor module mainly includes MTI attitude measurement module and MS5803 high precision barometer. The wireless communication module provides SBUS interface, which is mainly used to receive SBUS remote receiver signal and output SBUS signal, control the cloud head and capture the infrared control camera. At the same time, the UART bus interface is provided for the communication between the data transmission module and the graphic transmission module between the flight control platform and the earth station. In the aspect of software design, considering the reliability and real-time requirement of UAV to software platform, this paper adopts the software platform design scheme based on Nuttx real-time embedded operating system. The system adopts UNIX-like architecture and has complete task scheduling module, file management system and memory management module, which is very suitable for complex peripheral scenarios of flight control platform and various task requirements. At the same time, a micro-object agent inter-process communication module is introduced to solve the real-time problem of inter-process data transmission. The inter-process communication system is a real-time communication system, which is responsible for the information exchange between sensors or between sensors and upper applications. These measures enable the software platform to achieve better real-time, portability and reliability. After the completion of the whole hardware platform and software platform, the hardware of the flight control platform and related sensor networks, the operating system is verified and tested. Finally, the feasibility and practicability of the whole flight control platform are verified. The final flight test also proved that the flight control system can meet the project design requirements.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：V279;V249.1;TP332

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