Angular Velocity Estimation Using Non-Coplanar Accelerometer Array
Angular Velocity Estimation Using Non-Coplanar Accelerometer Array
复制标题
DOI：
10.1109/jsen.2021.3107470
复制
发表时间：
2021-10-15
影响因子：
4.3
通讯作者：
Vikas, Vishesh
中科院分区：
文献类型：
--
作者：
Maynard, Michael;Vikas, Vishesh
在过去的几十年里，人们广泛研究了无陀螺惯性测量单元（GF-IMU），以克服陀螺仪的局限性。提出了一种非共面加速度计阵列（NAA），用于非特定几何布置的四个或更多的三轴加速度计的非共面约束的角速度估计。非共面特殊排列的证明也提供了深入了解传感器噪声的传播和噪声协方差矩阵的构建。系统噪声取决于（传感器之间的）相对位移矩阵的奇异值。提出了一种具有不相关过程和测量噪声的动态系统模型，其中加速度计读数同时用作过程和测量输入。使用扩展卡尔曼滤波器（EKF），离散化和线性化的连续离散时间动态系统的角速度估计。在立方体-NAA（Cu-NAA）上执行模拟，所述立方体-NAA包括放置在立方体的不同顶点处的四个加速度计。他们分析了静态和动态运动的估计误差，因为加速度计（立方体方向的四个加速度计）之间的距离是变化的。在这里，观察到系统噪声与立方体边缘的长度成反比地减小，因为布置保持相同。因此，仿真结果表明，估计的标准误差与边长的渐近下降。实验在具有五个反射光学标记的Cu-NAA上进行。使用ViconCIRCLED LATIN CAPITAL LETTER R视觉跟踪反射标记以构建地面真实角速度。这种独特的实验装置，除了提供三个旋转运动自由度外，还允许三个空间平移度（Cu-NAA在空间中的线性加速）。仿真和实验结果表明，所提出的EKF相比，与相关的过程和测量噪声的性能更好。
Over the last few decades, Gyro-Free Inertial Measurement Units (GF-IMUs) have been extensively researched to overcome the limitations of gyroscopes. This research presents a Non-coplanar Accelerometer Array (NAA) for estimating angular velocity with non-specific geometric arrangement of four or more triaxial accelerometers with non-coplanarity constraint. The presented proof of non-coplanar special arrangement also provides insights into propagation of the sensor noise and construction of the noise covariance matrices. The system noise depends on the singular values of the relative displacement matrix (between the sensors). A dynamical system model with uncorrelated process and measurement noise is proposed where the accelerometer readings are used simultaneously as process and measurement inputs. The angular velocity is estimated using an Extended Kalman Filter (EKF) that discretizes and linearizes the continuous-discrete time dynamical system. The simulations are performed on a Cube-NAA (Cu-NAA) comprising four accelerometers placed at different vertices of a cube. They analyze the estimation error for static and dynamic movement as the distance between the accelerometers (four accelerometers in cube-orientation) is varied. Here, the system noise is observed to decrease inversely with the length of the cube edge as the arrangement is kept identical. Consequently, the simulation results indicate asymptotic decrease in the standard error of estimation with edge length. The experiments are conducted on a Cu-NAA with five reflective optical markers. The reflective markers are visually tracked using ViconCIRCLED LATIN CAPITAL LETTER R to construct the ground truth angular velocity. This unique experimental setup, apart from providing three degrees of rotational freedom of movement, also allows for three degrees of spacial translation (linear acceleration of the Cu-NAA in space). The simulation and experimental results indicate better performance of the proposed EKF as compared to one with correlated process and measurement noises.