Institute of Optics and Electronics, Chinese Academy of Science, Chengdu 610209, China.
Key Laboratory of Optical Engineering, Chinese Academy of Sciences, Chengdu 610209, China.
Sensors (Basel). 2018 Jul 4;18(7):2153. doi: 10.3390/s18072153.
In the charge-coupled device (CCD) and micro-electro-mechanical system (MEMS) accelerometer based low-cost multi-loop optoelectronic control system (OCS), due to accelerometers’ drift and noise in low frequency, the disturbance suppression (DS) is insufficient. Previously, based on the acceleration and position dual-loop control (ADLC), researchers combined a disturbance observer (DOB) with a virtual velocity loop to make some medium-frequency DS exchange for low-frequency performance. However, it is not optimal because the classic DOB based on accelerometers’ inaccurate signals cannot observe accurate disturbance in low frequency and the velocity based on a CCD and accelerometer time-domain fusion carried the CCD’s delay, resulting in the drop of medium-frequency DS. In this paper, considering the CCD’s advantage in low frequency and the accelerometer’s strength in high frequency, we propose to fuse their signals twice with a modified complementary filter method to respectively acquire an acceleration and velocity. The new acceleration with no drift and less noise but lower bandwidth creates a new acceleration model and is only used in fusion DOB (FDOB), while the velocity with little delay is to build an additional velocity loop. Compared with the traditional DOB enhanced by the time-domain fusion velocity loop, experiments verify that the proposed multiple fusion would apparently enhance the system’s DS, especially in low and medium frequency.
在基于电荷耦合器件(CCD)和微机电系统(MEMS)的低成本多环光电控制系统(OCS)中,由于加速度计在低频时的漂移和噪声,干扰抑制(DS)不足。以前,基于加速度和位置双环控制(ADLC),研究人员将干扰观测器(DOB)与虚拟速度环相结合,使一些中频 DS 交换低频性能。然而,这并不是最优的,因为基于加速度计不准确信号的经典 DOB 无法在低频观测到准确的干扰,而基于 CCD 和加速度计时域融合的速度则带有 CCD 的延迟,从而降低了中频 DS。在本文中,考虑到 CCD 在低频时的优势和加速度计在高频时的优势,我们提出使用改进的互补滤波器方法对它们的信号进行两次融合,分别获取加速度和速度。无漂移、噪声小但带宽较低的新加速度产生了新的加速度模型,仅用于融合 DOB(FDOB),而延迟较小的速度则用于构建附加的速度环。与传统的通过时域融合速度环增强的 DOB 相比,实验验证了所提出的多次融合将明显增强系统的 DS,尤其是在低频和中频。