Improvement of Bending Vibration Suppression Performance for Galvano Mirror by Self-Sensing Actuation

Abstract

This paper presents a method for suppressing the bending vibration of galvano mirrors used in laser positioning systems. Fast and highly precise positioning of the mirror is vitally important for these systems. Thus, the flatness of the mirror should be maintained to ensure highly precise laser positioning. However, mechanical resonant vibrations of the mirror, which are excited by the moment force during positioning, lead to residual vibrations after positioning; these vibrations degrade the flatness of the mirror and the laser manufacturing accuracy. In this paper, therefore, a vibration suppression method is proposed in which a piezoelectric element is mounted on the mirror so as to utilize the multifunctionality of the piezoelectric element by applying it as both actuator and sensor in the vibration suppression controller design. The applicability of the proposed approach to industrial galvano scanners has been verified by performing experiments with a prototype.

Analysis of open-loop characteristics on SISO sampled-data positioning control system

“…The head-positioning control system is one of the most widely used sampled-data positioning control systems all over the world and essential to infrastructure for our advanced information society. Moreover, the control system and characteristics of the controlled object in the head-positioning control systems are similar to other precise positioning systems such as a galvano scanner, or a linear X-Y stage (Seki and Iwasaki, 2014;Sakata et al, 2014). Therefore, to show the validity of the proposed method, we employ the head-positioning system of HDDs as a textbook example (Franklin et al, 1998).…”

“…The wide availability of inexpensive microprocessors has made sampled-data control systems very popular for positioning control in mechatronic products (Hirata et al, 1999;Hirata and Tomizuka, 2005;Ishikawa, 2008;Fujimoto, 2013;Seki and Iwasaki, 2014;Sakata et al, 2014;Ohnishi et al, 2016;. As a result, a sampled-data control system should be assumed to be the standard control system for mechatronic products.…”

Recent advances and outlook in industrial instrumentation and mechatronics control

“…Vibration suppression control is also an important technology in the industrial field. Seki and Iwasaki proposed a vibration suppression control method by self‐sensing actuation , Sakata et al . examined self‐resonance cancelation for a two‐mass system , and Kondo et al .…”

Application of self-sensing technique for position control considering vibration suppression in piezo-driven stage

“…In order to solve the problem, a part of CC bridge circuit in Fig. 4 can be constructed by a software as a virtual bridge circuit [12]. From (5), since v 2 is determined by supplied voltage v c regardless of v p , v 2 may not need to be directly measured by the analog circuit.…”

“…Since the piezoelectric element has a function of both sensor and actuator, vibration detection and suppression can be simultaneously achieved by self-sensing techniques [3] [11]. In the self-sensing technique, a simple bridge circuit is only added on the system to separate the intermingled sensor and actuator signals [12]. Minor feedback loop can be designed to suppress the resonant vibration modes based on the detected signal through the bridge circuit, where the reduction of sensitivity characteristic at around the vibration frequencies is especially considered to attenuate residual vibration for the reference and disturbance.…”