Globally Asymptotic Stable Attitude Estimation with Application to MEMS Sensors

一种基于MEMS传感器的全局渐进稳定的姿态估计算法

School of Automation, Northwestern Polytechnical University, Xi'an 710129, China

Received: 10 June 2019

Abstract

Aiming at the requirement of attitude information module with high precision, small size and low power consumption for the control of miniature UAV, a practical attitude estimation algorithm based on the micro-electro-mechanical sensor is proposed in this paper, which realizes the accurate estimation of the attitude of the UAV under the condition of low acceleration. A low-cost MEMS gyroscope, accelerometer, and magnetometer are used in the system. The Euler angle is obtained by the state observer method based on Direction Cosine Matrix (DCM) which can be got by fusing the sensor data. Firstly, based on the basic idea of TRIAD algorithm, a method to determine the attitude rotation matrix by accelerometer and magnetometric measurement is proposed. Compared with the traditional method, this method does not have to calculate the inverse of the matrix. Secondly, a state observer is intended to estimate the attitude of the system. The state observer doesn't have to observe the bias of the gyroscope, but still ensures the convergence of the Euler angle. Finally, the simulation based on the actual sampling data of the MEMS sensor shows that the output of the state observer designed in this paper still has high accuracy and good dynamic characteristics under the condition of gyroscope noise and bias.

摘要

针对微小型无人飞行器的控制对高精度、小体积、低功耗的姿态信息的需求，提出了一种实用的基于MEMS传感器的姿态解算算法，实现了在低加速度状态下对飞行器姿态的精准估计。该算法将MEMS陀螺仪、加速度计和磁力计的数据作为输入，采用一种全局渐进稳定的状态观测器方法对3种传感器数据进行融合，进而得到欧拉角输出。首先，针对实际航姿参考系统（AHRS）设计的需求，改进了TRIAD算法，使用加速度计和磁力计的量测向量来估计姿态旋转矩阵。与传统方法相比，该方法避免了矩阵的求逆过程。其次，在获得了量测向量确定的姿态旋转矩阵的基础上，设计了无需观测陀螺仪零偏的状态观测器，并证明了姿态角的收敛性。最后，基于实际MEMS传感器采样数据的仿真结果表明，在存在陀螺仪噪声和零偏的情况下，文中设计的状态观测器输出依然具有较高的精度和较好的动态特性。