TY - GEN
T1 - Vibration Suppression in the Passively-Supported Direction by Varying Bias Currents in Magnetic Suspension System
AU - Mizuno, Takeshi
AU - Javed, Asief
AU - Ishino, Yuji
AU - Yamaguchi, Daisuke
AU - Takasaki, Masaya
N1 - Funding Information:
*Resrach supported by JST Matching Planer Program MP27215667884. Takeshi MIZUNO is with Saitama University, Saitama, 338-8570 JAPAN (phone: +81-48-858-3455; fax: +81-48-858-3712; e-mail: mizar@ mech.saitama-u.ac.jp). Asief JAVED is with Saitama University, Saitama, 338-8570 JAPAN (e-mail: asiefjaved@control. mech.saitama-u.ac.jp). Yuji ISHINO is with Saitama University, Saitama, 338-8570 JAPAN (e-mail: yishino@ mech.saitama-u.ac.jp). Daisuke YAMAGUCHI is with Saitama University, Saitama, 338-8570 JAPAN (e-mail: yamaguchi14@ mech.saitama-u.ac.jp). Masaya TAKASAKI is with Saitama University, Saitama, 338-8570 JAPAN (e-mail: masaya@ mech.saitama-u.ac.jp).
Publisher Copyright:
© 2018 European Control Association (EUCA).
PY - 2018/11/27
Y1 - 2018/11/27
N2 - Vibration in the passively-supported direction is reduced by varying the stiffness in the suspension. The magnetic suspension system using the attractive force of an electromagnet is inherently unstable in the normal direction; active control is necessary to achieve stable suspension. In contrast, it is usually stable in the lateral direction because of the edge effects in the magnetic circuits. However, damping in this direction is quite small so that vibration is easily induced. In this work, varying stiffness controls are applied to suppress the vibration. An experimental apparatus was built to examine the efficacy of the varying stiffness control. It has two electromagnets operated differentially. To adjust the stiffness in the passively-supported direction, the bias current of each electromagnet is varied simultaneously. First, the bias current is varied stepwise. The effect of the amplitude of step on vibration suppression is examined. Then, the bias current is varied continuously to avoid erroneous operations caused by noise included in the sensor signal. The efficacy of approximating the sign function by a continuous function is demonstrated experimentally.
AB - Vibration in the passively-supported direction is reduced by varying the stiffness in the suspension. The magnetic suspension system using the attractive force of an electromagnet is inherently unstable in the normal direction; active control is necessary to achieve stable suspension. In contrast, it is usually stable in the lateral direction because of the edge effects in the magnetic circuits. However, damping in this direction is quite small so that vibration is easily induced. In this work, varying stiffness controls are applied to suppress the vibration. An experimental apparatus was built to examine the efficacy of the varying stiffness control. It has two electromagnets operated differentially. To adjust the stiffness in the passively-supported direction, the bias current of each electromagnet is varied simultaneously. First, the bias current is varied stepwise. The effect of the amplitude of step on vibration suppression is examined. Then, the bias current is varied continuously to avoid erroneous operations caused by noise included in the sensor signal. The efficacy of approximating the sign function by a continuous function is demonstrated experimentally.
UR - http://www.scopus.com/inward/record.url?scp=85059824540&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85059824540&partnerID=8YFLogxK
U2 - 10.23919/ECC.2018.8550236
DO - 10.23919/ECC.2018.8550236
M3 - Conference contribution
AN - SCOPUS:85059824540
T3 - 2018 European Control Conference, ECC 2018
SP - 971
EP - 976
BT - 2018 European Control Conference, ECC 2018
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 16th European Control Conference, ECC 2018
Y2 - 12 June 2018 through 15 June 2018
ER -