MEMS Inertial Sensors-Based Multi-Loop Control Enhanced by Disturbance Observation and Compensation for Fast Steering Mirror System

Abstract

In this paper, an approach to improve the disturbance suppression performance of a fast steering mirror (FSM) tracking control system based on a charge-coupled device (CCD) and micro-electro-mechanical system (MEMS) inertial sensors is proposed. The disturbance observation and compensation (DOC) control method is recommended to enhance the classical multi-loop feedback control (MFC) for line-of-sight (LOS) stabilization in the FSM system. MEMS accelerometers and gyroscopes have been used in the FSM system tentatively to implement MFC instead of fiber-optic gyroscopes (FOG) because of its smaller, lighter, cheaper features and gradually improved performance. However, the stabilization performance of FSM is still suffering a large number of mechanical resonances and time delay induced by a low CCD sampling rate, which causes insufficient error attenuation when suffering uncertain disturbances. Thus, in order to make further improvements on the stabilization performance, a cascaded MFC enhanced by DOC method is proposed. The sensitivity of this method shows the significant improvement of the conventional MFC system. Simultaneously, the analysis of stabilization accuracy is also presented. A series of comparative experimental results demonstrate the disturbance suppression performance of the FSM control system based on the MEMS inertial sensors can be effectively improved by the proposed approach.

Three Closed-Loop Feedback Control System with Dual Disturbance Observers of an Optoelectronic Stable Control Platform

“…It can be seen from Equation (4) that when the fitting result of the acceleration G a is approximately equal to the actual controlled object of the acceleration G a (meaning that G a ≈ G a ), the design of the disturbance compensator of the acceleration does not affect the stability of the system [11]. Therefore, the robustness of the system is only limited by the design parameters of the position loop disturbance compensator C f p .…”

“…According to the frequency domain transformation relationship s = jω, Equation (11) should be independent of any frequency, so we divided Equation (11) into the following two cases:…”

“…However, this method is not designed for the suppression of the disturbance. To solve this problem, Deng Chao introduced a disturbance observer into the acceleration loop to focus on improving the disturbance rejection capability of the middle-frequency band [11]. The drift of the MEMS (micro-electro-mechanical system) accelerometers in the low-frequency range is the reason why the acceleration loop disturbance observer cannot improve the low-band disturbance rejection capability [12].…”

“…The CCD (charge-coupled device) sensor used in the position loop has advantages, such as high sensitivity and fast response in the low-frequency range [11]. According to those features, this paper proposed a new method, named dual disturbance observers (dual DOB), of introducing two disturbance observers in the position loop and the acceleration loop.…”

Dynamic Stress Measurement with Sensor Data Compensation

“…Recently, various methods for sensor compensation have gradually attracted researchers' attention because of its ability to reduce or eliminate the deficiency caused by error data on the systems [5][6][7][8][9][10][11][12][13]. For the compensation method of sensor data, most researches focus on hardware compensation based on physical or circuit characteristics of electronic components, such as magnetic field pulses, charge-coupled device, micro-electro-mechanical system, even material modification [6][7][8][9]. There are also a few high precision sensor methods with hardware and software compensation for temperature based on physical or circuit characteristics of the electronic elements [10,11].…”