Small Unmanned Aerial Vehicle Automatic Control System Design And Retrofit

In recent years, unmanned aerial vehicle(UAV) has a rapid development both in technical progress and market development. This paper begins the software and hardware research of automatic control system central on a small gas helicopter.This paper chose a 90 gasoline helicopter, multiple sets of servo adopts advanced large digital torque servo module to enhance the accuracy and real-time performance of control; Landing gear and some components have been adjusted and improved necessarily to enhance the stability of bearing parts; Adding new sensors based on the original system of circuit board to improve the precision of the flight control. Especially, this paper introduces the implementation and operations of retrofit on autopilot, the framework of circuit and software have been structural reformed in a wide range, and add a new source of data input; rearranging and testing the communication protocol between ground system, flight control system and various components to make the whole electric control system more perfect. In order to transmit the attitude of flight data and other necessary data to the ground system in real-time so that the background system analyzing, we add the Digital Transmitter-Receiver based on Zigbee technology and corresponding interface, easing the contradiction between the transmitting of large amount of data and real-time, providing a platform for the further perfecting of soft and hardware.The calculation of the attitude algorithm is an important part of the whole automatic control system. The hardware circuit designing, the writing of data transmission protocol between the double CPU and sensors, attitude algorithm processing and algorithm software are the core issues of this paper. New sensors adopt micro mechanical(MEMS) devices, communicating with the CPU by the I2C protocol, and inherited the style of communication between other sensors chip and CPU, which make it easy to reform the board and system. In this paper, we study and adopt the quaternion method to update the attitude, and use four-order Range-Kuttle method to calculate and update the attitude matrix, the speed and precision of calculation have reached the desired effect.