Method determinate angle of rotation of an IMU application for UAV Trinh Dinh Quan Southern TaiWan University

1.Introduction about camera auto balancing system of UAV 2.Proposal auto balancing platform 3.Step by step solving rotation (attitude) of an IMU O Outline

UAV is without pilot, it has some problems when taking the picture from camera because of vibration of UVA when plying due to disturbance such as wind … To overcome this problem; an auto-balancing photogrammetric platform was designed in this project. A proposed auto-balancing photogrammetric platform includes an Inertial Measurement Unit (IMU) for measuring three angles of Roll, Pitch, and Yaw. With this proposed platform, we can easily take a photo from camera with small disturbance by auto adjusting three angles of Roll, Pitch, and Yaw to get desired direction O Introduction

Proposal auto balancing platform A proposed platform includes a 4-link mechanism for motions around three directions corresponding to three angles of Roll, Pitch, and Roll which are measured by an Inertial Measurement Unit (IMU). Three servo motors are used as actuator for rotating around three directions. This proposed platform will be mounted at UAV. Direction of platform can be set and controlled by a microcontroller via PID algorithm. Schematic of a proposed platform was shown in Figure.

Step 1 : Initialization (alignment): To determine the initial attitude including roll, pitch, and heading. Step 2 : Parameter transformation. Step3 : Update attitude. O Step by step solving rotation (attitude) of an IMU Figure 1: local level frameFigure 2: Attitude presentation

Determining heading (Gyro compassing)

Step 2: Parameter transformation Determine DCM matrix from Euler angles (attitude) For optimal in computation the attitude is usually expressed in quaternion form:

Step 3: Update attitude

Updated quaternion: Where: Calculate updated DCM matrix Calculate updated attitude: