Study And Design Of Wireless Remote Control Based On Bluetooth Protocol In Multi-rotor UAV

With the development of flight-control algorithm and the capital investment,the multi-rotor UAV,as the mainstream of small UAV,has been researched in many colleges and companies and widely used in various fields.However,the m UAV mostly use model UAV remote controller,that is high-cost,bulky,and low flexibility,as a part of fly control units.Besides that,faced with increasingly complex applications,UAV flight control chip solution is the research hotspot that makes the product more flexible and scalable.And FPGA based flight control customized realization can be used as prototype verification of UAV chip circuits design,which can accelerate the research process of the UAV chip solution.Aiming at these problems,this paper presents a novel wireless control approach instead of the traditional multi-rotor UAV remote control approach via Bluetooth protocol.The approach consists of two subsystems: an Android based Bluetooth remote controller App and AMBA based multi-rotor UAV data processing subsystem.The Bluetooth HC-05 serial port module is used as a wireless link to realize control transmission between the two subsystems.The Android Bluetooth controller App is the simplification of model UAV remote controller,which realizes left or right stick controlling,one key locking or unlocking,and adjusting PID coefficients.In order to distinguish control data and PID data,different data packets are designed for different data.In order to increase the flexibility of the App,the JAVA reflection mechanism is utilized to realize automatic pairing and connection.In addition,this paper takes advantage of CRC-CCITT algorithm for second check in Bluetooth data transmission to guarantee control data's correctness and integrity.The AMBA based UAV data processing subsystem is in charge of receiving,checking and processing Bluetooth data.The FPGA circuit consists of AHB part and APB part.The APB part is designed for controlling peripheral interface,including the Bluetooth serial port module,debug serial port module,watch-dog module,APB bridge module,etc.The AHB part is responsible for data processing,including data processing master module,configuration monitor master module,bus arbiter module,etc.This work uses Android Studio as App software development environment,and utilizes the Zedboard based on Zynq7020 core as hardware realization platform.The design works with STM32 debug system to test the designed system.Using the Bluetooth RSSI,average time delay and data accuracy as performance testing standards of the system,the results show that the maximum valid transmission distance of the design can be up to 20 meters,which is reliable and feasible for the low-cost UAV.This Bluetooth control system is low-cost,low-power,and flexible.It simplifies control network,and is simple maintenance.