sensors Article
A New Linear Oscillatory Actuator with Variable Characteristics Using Two Sets of Coils Fumiya Kitayama *, Katsuhiro Hirata, Noboru Niguchi and Masashi Kobayashi Department of Adaptive Machine Systems, Graduate School of Engineering, Osaka University, Osaka, 565-0871, Japan;
[email protected] (K.H.);
[email protected] (N.N.);
[email protected] (M.K.) * Correspondence:
[email protected]; Tel.: +81-6-6879-7553 Academic Editors: Slawomir Wiak and Manuel Pineda Sanchez Received: 6 January 2016; Accepted: 10 March 2016; Published: 15 March 2016
Abstract: Nowadays, electromagnetic linear oscillatory actuators are used as vibration control devices because of their high controllability. However, there is a problem that thrust and vibration are small at a wide drive frequency range. In order to improve this problem, we propose a new linear oscillatory actuator that can easily change its own characteristics by using two sets of coils. Through finite element analysis, large vibration was observed at 100 Hz in a series connection, and large vibration and high thrust were observed at 70 Hz and 140 Hz in a parallel connection. From these results, we verified that the actuator had two different characteristics due to switchable connections, and could generate high thrust and large vibration by smaller currents at a wide drive frequency range. Keywords: linear oscillatory actuator; variable characteristics; finite element analysis
1. Introduction Recently, problems have been caused by mechanical vibrations [1,2]. Passengers often feel uncomfortable, especially in automobiles by a frame vibration that is generated by an engine. In order to solve the problem, active vibration control devices have been developed [3–7]. In these devices, many electromagnetic linear oscillatory actuators are used because of their high controllability. However, the electric power of these actuators is relatively high. Therefore, a high thrust and large vibration due to small currents have been required at a wide drive frequency range. In previous studies, actuators with improved magnetic circuits have been proposed [8,9]. However, the effectiveness of the improved magnetic circuit is still low for the high thrust and vibration characteristics. Here, we have developed an actuator using a regenerative energy, as shown in Figure 1 [10]. Furthermore, the actuator is verified to realize variable characteristics under high thrust and large vibration by changing the coil connection, as shown in Figure 2. However, the previous actuator has difficulty manufacturing because a mover is sandwiched by two stators. In this paper, a new and simple actuator that has variable characteristics for high thrust and large vibration is proposed [11]. The operational principle is described, and its characteristics are computed using finite element analysis. Finally, the effectiveness of the proposed actuator is discussed.
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Figure 1. Basic construction of our previous actuator. Figure Basic construction of our previous actuator. Figure1.1. 1.Basic Basicconstruction constructionof ofour ourprevious previousactuator. actuator. Figure
Figure 2. Connections of coils in previous actuator.
2. Proposed Actuator
Figure 2. 2. Connections Connections of of coils coils in in previous previous actuator. Figure actuator. Figure 2. Connections of coils in previous actuator.
The cross-section 2. Proposed Proposed Actuatorview and coil connection of the proposed actuator are shown in Figures 3 and Actuator 2. Proposed Actuator 4. In the proposed actuator, variable characteristics can be realized by changing the coil connection The cross-section 3 and 4. cross-section view viewand andcoil coilconnection connectionofofthe theproposed proposedactuator actuatorare areshown shownininFigures Figures 3 and in series parallel. Due to and the mechanism, a high thrust and vibration be generated at a3wide The or cross-section view coil connection of the proposed actuator can are shown in Figures and In thethe proposed actuator, variable characteristics cancan be be realized by by changing thethe coilcoil connection in 4. In proposed actuator, variable characteristics realized changing connection frequency range. In addition, the manufacturability be improved due tothe introduction of a 4. In the proposed actuator, variable characteristics cancan be realized by changing coil connection series or or parallel. Due in series parallel. Duetotothe themechanism, mechanism,a ahigh highthrust thrustand andvibration vibrationcan can be be generated generated at at a wide piled coil.or parallel. Due to the mechanism, a high thrust and vibration can be generated at a wide in series frequency thethe manufacturability can be improved due to introduction of a piledof coil. frequency range. range.InInaddition, addition, manufacturability can be improved due to introduction a frequency range. In addition, the manufacturability can be improved due to introduction of a piled coil. piled coil.
Figure3.3.Basic Basicconstruction constructionof ofproposed proposedactuator. actuator. Figure
Figure 3. of Basic construction of proposedThe actuator. The actuator mainly consists a construction mover and of a proposed stator. mover is composed of a yoke, Figure 3. Basic actuator. two ring-shaped permanent magnets magnetized in the moving direction, and a shaft made of non-ferromagnetic material. The stator is composed of yokes, two springs, two sets of coils, and supporting parts made of non-ferromagnetic material. The actuator can be easily manufactured because the stator is located outside the mover. As shown in Figure 4, the coil connection can be
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changed in series or parallel. In the series connection, Coil 1 and Coil 2 are connected with a power supply. In the parallel connection, Coil 1 is connected with a power supply while Coil 2 is connected with a capacitor. Furthermore, electric switching devices are necessary to change the coil connection. Additionally, the number of switching devices increases more than that in the previous actuator Sensors 2016, 16, 377 3 of 8 because the coil connection is slightly complicated. Sensors2016, 2016,16, 16,377 377 Sensors
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Figure Connections of coils in proposed actuator. Figure Connectionsof ofcoils coilsin in proposed actuator. Figure 4.4.Connections Connections actuator. Figure 4.4. of coils inproposed proposed actuator.
The ofofaaamover mover and stator. The moverisis iscomposed composedofof ofaaayoke, yoke, two Theactuator actuatormainly mainlyconsists consistsof moverand andaaastator. stator.The Themover mover composed yoke, two The actuator mainly consists two The operational principles at each connection are shown in Figures 5 and 6. When the coils are ring-shaped permanent magnets magnetized in the moving direction, and a shaft made ring-shaped permanent permanent magnets magnets magnetized magnetized inin the the moving moving direction, direction, and and aa shaft shaft made made ofofof ring-shaped notnon-ferromagnetic excited, the magnetic flux distribution around the upper ringtwo magnet is the same the lower ring material. The isis composed of yokes, two springs, two setsas of coils, and non-ferromagnetic material. Thestator statoris composed ofyokes, springs, two sets coils, and non-ferromagnetic material. The stator composed of springs, two sets ofof coils, and magnet, and no thrusts are generated. In the series connection, currents in Coil 1 and Coil 2 produce supporting material. The actuator actuatorcan canbe beeasily easilymanufactured manufactured supportingparts partsmade madeof non-ferromagnetic material. material. The actuator can be easily manufactured supporting parts made ofofnon-ferromagnetic non-ferromagnetic unbalanced magnetic fluxes, which generate a thrust the upper direction. this way, an AC current because outside mover. As shown Figure 4,the theIn coil connection can be becausethe thestator statoris islocated located outside themover. mover. Asin shown Figure the coil connection can be because the stator is located the As shown ininFigure 4,4, coil connection can be in changed the coils in generates an AC thrust, and theconnection, mover is oscillated [7,12]. theconnected parallel connection, when parallel. InInthe series connection, Coil11and and Coil2In are connected with apower power changed seriesor or parallel. the series connection, Coil 22are are connected with changed ininseries series or parallel. series Coil Coil with aapower supply. Inthe theparallel parallel connection, Coil11is connected with supply while Coil isis connected In connection, isisconnected connected with power supply while Coil22is 2and connected thesupply. mover is oscillated due to an ACCoil current in Coil 1, an induced voltage iswhile generated, an induced supply. In the parallel connection, with aapower supply Coil connected with a capacitor. Furthermore, electric switching devices necessary to change the coil connection. with a capacitor. Furthermore, electric switching devices are necessary to change the coil connection. with a capacitor. Furthermore, switching devices are necessary to change the coil connection. current flows in Coil 2. In this time, the amplitude and the phase angle between Coil 1 and Coil 2 are Additionally, theother number switching devices increases more than that the previous actuator Additionally, the number devices more than inin actuator Additionally, the number ofofswitching devices increases thanthat that inthe theprevious previous actuator different from each because they depend onincreases the drive frequency. Therefore, Coil 2 can generate because the coil connection is slightly complicated. because the coil connection complicated. because connection is slightly complicated. thrust, andthe thecoil mover is oscillated by the thrusts.
Figure principle in series. Figure5. Operationalprinciple principleinin series. Figure 5.5.Operational Operational series. Figure 5. Operational principle in series.
Figure6.6.Operational Operationalprinciple principleininparallel. parallel. Figure
Figure 6. Operational principle in parallel. Figure 6. Operational principle in parallel. Theoperational operationalprinciples principlesatateach eachconnection connectionare areshown shownininFigures Figures55and and6.6.When Whenthe thecoils coilsare are The operational principles at each connection are in Figures 5 isand 6.same When are notThe excited, themagnetic magnetic fluxdistribution distribution aroundthe theshown upperring ring magnet isthe the same asthe thecoils lower not excited, the flux around upper magnet as the lower not excited, theand magnetic fluxare distribution around the upper ring magnet is the same the lower ring magnet, and nothrusts thrusts are generated. Inthe theseries series connection, currents Coil11as and Coil ring magnet, no generated. In connection, currents ininCoil and Coil 22 produce unbalanced magnetic fluxes, whichgenerate generate thrust theupper upper direction. Inthis this way, an 2 ring magnet, and no magnetic thrusts are generated. In the series connection, currents in Coil 1 and Coil produce unbalanced fluxes, which aathrust ininthe direction. In way, an
produce unbalanced magnetic fluxes, which generate a thrust in the upper direction. In this way, an
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In the proposed actuator, a thrust constant is expressed by Equation (1). F Iinput
“
A1 I1 ` A2 I2 Iinput
(1)
where F is the thrust, I1 and I2 are the currents in Coil 1 and Coil 2, respectively, Iinput is the input current, and A1 and A2 are thrust constants of Coil 1 and Coil 2, respectively. In the series connection, the current in Coil 1 and Coil 2 are equal to the input current, and a thrust constant is derived as Equation (2). In the parallel connection, the current in Coil 1 and Coil 2 are equal to the input current and induced current, respectively, and a thrust constant is derived as Equation (3). A1 Iinput ` A2 Iinput F “ ““ A1 ` A2 Iinput Iinput F Iinput
“
A1 Iinput ` A2 Iinduced I ““ A1 ` A2 induced Iinput Iinput
(2)
(3)
where Iinduced is the induced current. From these equations, a thrust constant is constant in the series connection and is not constant in the parallel connection. When the actuator is driven at a constant frequency, a thrust constant in the series connection is higher than that in the parallel connection because the phase of the induced current is almost opposite to the input current, and thrusts generated by each current are cancelled in the parallel connection. When the actuator is driven at other frequencies, a thrust constant in the series connection is lower than that in the parallel connection because the phase of the induced current is almost the same as the input current, and thrusts generated by each currents are superimposed in the parallel connection. The oscillation of the mover is influenced by the mechanical resonance in the series connection. On the other hand, the oscillation is influenced by the mechanical resonance and induced current in the parallel connection. From these operations, the frequency characteristics of the thrust and vibration are different and depend on the conditions of the coils. In other words, high thrusts and large vibration can always be generated under lower current by changing the coil connections according to the drive frequency. 3. Analysis Method In order to verify the operational principle of the proposed actuator, a magnetic field analysis with a motion and circuit equations was conducted as shown in Figure 7 [13,14]. In the magnetic field analysis, the magnetic fluxes are calculated from Maxwell's equation using the 2-D finite element method. Additionally, the electromagnetic force is calculated by the Maxwell's stress method. In the circuit analysis, a current in the series connection is calculated from a circuit equation shown in Equation (4). . . V “ pR1 ` R2 q Iinput ` N1 ψ1 ` N2 ψ2 (4) Similarly, the currents in the parallel connection are calculated from the following two circuit equations: . V “ R1 Iinput ` N1 ψ1 (5) ż . 1 I dt (6) 0 “ R2 Iinduced ` N2 ψ2 ` C induced Finally, the mover position is calculated from a motion equation shown in Equation (7). ..
.
M x ` D x ` Kx “ F ˘ Fs
(7)
where V is the applied voltage from the power supply, N1 and N2 are the number of turns in Coil 1 and 2, respectively, R1 and R2 are the resistance of Coil 1 and Coil 2, respectively, Ψ1 and Ψ2 are the
Finally, the mover position is calculated from a motion equation shown in Equation (7). Mx Dx Kx F Fs
(7)
Sensors 377applied where2016, V is16, the
5 of 81 voltage from the power supply, N1 and N2 are the number of turns in Coil and 2, respectively, R1 and R2 are the resistance of Coil 1 and Coil 2, respectively, Ψ1 and Ψ2 are the interlinkage flux capacitor, MM is interlinkage flux per per turn turn of ofCoil Coil11and andCoil Coil2,2,respectively, respectively,CCisisthe thecapacitance capacitanceofofthe the capacitor, the mass of the mover, D is the damping coefficient, K is the spring constant, and F s is the friction is the mass of the mover, D is the damping coefficient, K is the spring constant, and Fs is the friction force. In the analyses, analyses, iron iron losses losses are are not not considered. considered. force. In the
START
Calculation of force
Setting of initial condition
Calculation of motion
Magnetic field analyses
Mesh modification
Calculation of circuit
No
t=end time? Yes
t=t+Δt
END
Figure 7. Flowcharts of the analysis method. Figure 7. Flowcharts of the analysis method.
4. AnalyzedResults Results 4. Analyzed A voltage that that has has an an amplitude amplitude of of 1.2 1.2 V V and and a A sinusoidal sinusoidal voltage a frequency frequency from from 20 20 to to 200 200 Hz Hz was was applied. The analysis conditions are shown in Table 1. applied. The analysis conditions are shown in Table 1. Table 1. Analysis condition. Table 1. Analysis condition. Coil 1 1 Coil Coil 2 2 Coil
Resistance (Ω) Resistance (Ω)
0.98 0.98
Number turns Number ofof turns
39 39
Resistance (Ω) Resistance (Ω)
0.98 0.98
Number turns Number ofof turns
38 38
Capacitance Capacitance(mF) (mF)
1
1
Magnetizationofofmagnets magnets(T) (T) Magnetization
1.3 1.3
MassofofMover Mover(g) (g) Mass
319 319
Springconstant constant(N/mm) (N/mm) Spring
106 106
Dampingcofficient cofficient(Ns/m) (Ns/m) Damping
10 10
Frictionforce force(N) (N) Friction
0.42 0.42
Figures 8 and 9 show the currents, thrusts, and mover positions at 70 and 100 Hz, respectively. Figures 8 and 9 show the currents, thrusts, and mover positions at 70 and 100 Hz, respectively. When the actuator is driven at 70 Hz, the thrust constants in the series and parallel connections are When the actuator is driven at 70 Hz, the thrust constants in the series and parallel connections are 21 Namp/Aamp, and 41 Namp/Aamp, respectively. Furthermore, when the actuator is driven at 100 Hz, the 21 Namp /Aamp , and 41 Namp /Aamp , respectively. Furthermore, when the actuator is driven at 100 Hz, thrust constants in the series and parallel connections are 21 Namp/Aamp and 3 Namp/Aamp, respectively. the thrust constants in the series and parallel connections are 21 Namp /Aamp and 3 Namp /Aamp , The thrust constant in the parallel connection is higher than that in the series connection at 70 Hz respectively. The thrust constant in the parallel connection is higher than that in the series connection because the phase difference of the currents is almost zero and is lower at 100 Hz because the phase at 70 Hz because the phase difference of the currents is almost zero and is lower at 100 Hz because difference is opposite, as shown in Figures 8c and 9c. The vibration amplitudes per input current the phase difference is opposite, as shown in Figures 8c and 9c. The vibration amplitudes per input amplitude (vibration constants) in the series and parallel connections are 0.41 mmamp/Aamp and current amplitude (vibration constants) in the series and parallel connections are 0.41 mmamp /Aamp and 0.91 mmamp /Aamp , respectively, at 70 Hz. The vibration constants in the series and parallel connections are 1.18 mmamp /Aamp and 0.23 mmamp /Aamp , respectively, at 100 Hz. The vibration constant in the series connection is larger at 100 Hz because of the mechanical resonance frequency (96 Hz) depending on the mover weight and the spring stiffness, and that in the parallel connection is larger at 70 Hz due to the higher thrust constant.
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1 1
0 Time, 0 s Time, s (a) Currents in series (a) Currents in series
Input current Input current
0 0
-1 -1 -0.015 -0.015
Induced current Induced current 0 Time, 0 s Time, s
Thrust, Thrust, NN
0.015 0.015
0.015 0.015
(c) Currents in parallel (c) Currents in parallel
0 0
0 0
Position Position -0.08 -4 -4 -0.015 0 0.015-0.08 Time, -0.015 0 s 0.015 Time, s (b) Thrust and mover position in series (b) Thrust and mover position in series 10 0.2 Thrust 10 0.2 Thrust 0 0 0 0
Position, Position, mmmm
Current, Current, AA
-0.4 -0.4 -0.015 -0.015
Thrust, Thrust, NN
Current, Current, A A
Input current
0 0
Position, Position, mmmm
0.91 mmamp/Aamp, respectively, at 70 Hz. The vibration constants in the series and parallel 0.91 mmamp/A amp1.18 , respectively, 70 Hz. vibration constants inat the andvibration parallel connections are mmamp/Aampat and 0.23 The mmamp /Aamp, respectively, 100 series Hz. The connections are 1.18 mm amp /A amp and 0.23 mm amp /A amp , respectively, at 100 Hz. The vibration constant in the series connection is larger at 100 Hz because of the mechanical resonance frequency constant in the series is largerand at 100 because of the mechanical frequency (96 Hz) depending onconnection the mover weight the Hz spring stiffness, and that in theresonance parallel connection Sensors 2016, 16, 377 6 of 8 (96 Hz) depending on the mover weight and the spring stiffness, and that in the parallel connection is larger at 70 Hz due to the higher thrust constant. is larger at 70 Hz due to the higher thrust constant. 0.08 4 Thrust 0.4 0.08 4 Input current Thrust 0.4
Position -10 -0.2 Position -10 -0.015 0 0.015-0.2 Time, -0.015 0 s 0.015 Time, s (d) Thrust and mover position in parallel (d) Thrust and mover position in parallel
0 0
2 2
0 Time, 0 s Time, s
0.015 0.015
(a) Currents in series (a) Currents in series Input current Input current
0 0 -2 -2 -0.015 -0.015
Induced current Induced current 0 0.015 0 s 0.015 Time, Time, s
(c) Currents in parallel (c) Currents in parallel
4 4
Thrust Thrust
Position Position
0 0
0 0 -4 -4 -0.015 -0.015
0.2 0.2
0 0 s Time, Time, s
-0.2 0.015-0.2 0.015
(b) Thrust and mover position in series (b) Thrust and mover position in series 5 0.4 Thrust 5 0.4 Thrust 0 0 0 0 -5 -5 -0.015 -0.015
Position Position 0 Time, 0s Time, s
Position, Position, mmmm
Current, Current, AA
-0.2 -0.2 -0.015 -0.015
Thrust, Thrust, NN
Current, Current, AA
Input current Input current
Position, Position, mmmm
0.2 0.2
Thrust, Thrust, NN
Figure 8. Analyzed results per time variation at 70 Hz. Figure 8. Analyzed results per time variation at 70 Hz. Figure 8. Analyzed results per time variation at 70 Hz.
-0.4 0.015-0.4 0.015
(d) Thrust and mover position in parallel (d) Thrust and mover position in parallel
Figure 9. Analyzed results per time variation at 100 Hz. Figure 9. Analyzed results per time variation at 100 Hz. Figure 9. Analyzed results per time variation at 100 Hz.
Figure 10 shows the analyzed results when the drive frequency is changed. From Figure 10a–d, Figurecurrent, 10 showsthrust, the analyzed resultsposition when theare drive frequencyby is changed. From Figure 10a–d, the input and mover influenced the mechanical resonance, Figure 10 shows the analyzed results when the drive frequency is changed. From Figure 10a–d, the input current, thrust, Inand moverthe position are influenced bymover the mechanical resonance, inductances, and capacitor. addition, input current, thrust, and position in the parallel the input current, thrust, and mover position are influenced by the mechanical resonance, inductances, inductances, and capacitor. In addition, the input current,atthrust, position in because the parallel connection are higher than those in the series connection almostand all mover drive frequencies the and capacitor. In addition, the input current, thrust, and at mover position in frequencies the parallel because connection connection are higher than those in the series connection almost all drive resistance of the coil that is connected to the power supply is small. Additionally, the input currentthe is are higher of than in the series connection at almost all drive frequencies because resistance of resistance thethose coil that is connected theparallel power supply is small. thethe input current is extremely small at 70 and 140 Hz in to the connection. As Additionally, shown in Figure 10e, the thrust the coil thatsmall is connected to 140 the power supply is small. Additionally, the input current is extremely extremely at 70 and Hz in the parallel connection. As shown in Figure 10e, the thrust constant in the series connection is constant with respect to the drive frequency, and that in the small at 70 Hz in the parallel connection. shownto in the Figure 10e, the thrustand constant in in the constant inand the 140 series is Hz. constant withAs respect drive frequency, the parallel has two peaks connection at 70 and 140 As shown in Figure 10f, the vibration constant inthat the series series connection is constant with respect to the drive frequency, and that in the parallel has two peaks parallel has two peaks at 70 and 140 Hz. As shown in Figure 10f, the vibration constant in the series at 70 and 140 Hz. As shown in Figure 10f, the vibration constant in the series connection has a peak at 100 Hz because of the mechanical resonance, and that in the parallel connection has two peaks at 60 and 140 Hz due to the higher thrust constant.
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3.6
Series Parallel
1.8
0 0
50 100 150 Frequency, Hz
200
Induced current, Aamp
peak at 100 Hz because of the mechanical resonance, and that in the parallel 7 of 8 connection has two peaks at 60 and 140 Hz due to the higher thrust constant. Input current, Aamp
connection Sensors 2016, 16,has 377 a
40
Position, mmamp
(a) Input current Thrust, Namp
Series Parallel
20
2
1 Parallel 0 0
50 100 150 Frequency, Hz
(b) Induced current
0.6
Series Parallel
0.3
0
0 0
50 100 150 Frequency, Hz
0
200
50 100 150 Frequency, Hz
30
0 50 100 150 Frequency, Hz
Vibration constant, mmamp/Aamp
Series Parallel
0
200
(d) Mover position
(c) Thrust 60
Thrust constant, Namp/Aamp
200
1.4
Series Parallel
0.7
200
(e) Thrust constant
0 0
50 100 150 Frequency, Hz
200
(f) Vibration constant
Figure 10. Analyzed results against drive frequency. Figure 10. Analyzed results against drive frequency.
Additionally, high thrust and large vibration can be generated by small currents from 60 to 80 Hz, Additionally, high largeconnection vibration can by small in currents from 60 to 80 Hz, and from 130 to 150 Hzthrust in theand parallel andbeatgenerated other frequencies the series connection. and from 130 to 150 Hz in the parallel connection and at other frequencies in the series connection. 5. Conclusions 5. Conclusions In this paper, we proposed a new linear oscillatory actuator that can manufacture easily and In this paper, we by proposed a new oscillatory actuator thatanalysis, can manufacture easily and control characteristics using two setslinear of coils. From finite element it was observed that control characteristics by using two sets of coils. From finite element analysis, it was observed that the the thrust constant was constant in the series connection and had two peaks in the parallel thrust constant was constant the series connection hadintwo the parallel connection. connection. Additionally, theinvibration constant had and a peak thepeaks seriesinconnection and had two Additionally, the vibration constant had a peak in the series connection and had two peaks in the peaks in the parallel connection. From these results, we verified that the actuator had two different parallel connection. From generate these results, verified actuatorusing had two different characteristics characteristics and could highwe thrust and that largethe vibration smaller currents at a wide and could generate high thrust and large vibration using smaller currents at a wide drive frequency drive frequency range by changing the connection according to the drive frequency. range by changing the connection according to the drive frequency. Acknowledgments: This work was supported by JSPS KAKENHI 14J00644. Acknowledgments: This work was supported by JSPS KAKENHI 14J00644. Author Contributions: K.H. and N.N. conceived the concept; F.K designed the actuator; F.K and M.K. analyzed Author Contributions: K.H. and N.N. conceived the concept; F.K designed the actuator; F.K and M.K. analyzed the data; data; F.K. F.K. wrote wrote the the paper. paper. the Conflicts of of Interest: Interest: The The authors authors declare declare no no conflict conflict of ofinterest. interest. Conflicts
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References 1.
2. 3. 4. 5.
6. 7.
8. 9. 10. 11. 12. 13. 14.
Alwi, H.; Edwards, C. Oscillatory Failure Case Detection For Aircraft Using an Adaptive Sliding Mode Differentiator Scheme. In Proceedings of the Americam Control Conference, San Francisco, CA, USA, 29 June–1 July 2011; pp. 1384–1389. Preda, V.; Cieslak, J.; Henry, D.; Bennani, S.; Falcoz, A. Microvibration Attenuation based on H8/LPV Theory for High Stability Space Missions. J. Phys. Conf. Ser. 2015, 659, 012026. [CrossRef] Nakaji, Y.; Satoh, S.; Kimura, T.; Hamabe, T.; Akatsu, Y.; Kawazoe, H. Development of an Active Control Engine Mount System. Veh. Syst. Dyn. 1999, 32, 185–198. [CrossRef] Matsuoka, H.; Mikasa, T.; Nemoto, H. NV counter-measure technology for a cylinder-on-demand engine—Development of active control engine mount. SAE Trans. 2004, 113, 181–186. Park, H.; Lee, B.H.; Lee, C.W. Design of An Active Control Engine Mount Using a Direct Drive Electrodunamic Actuator. In Proceedings of the ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Las Vegas, NV, USA, 4–7 September 2007; pp. 103–108. Lee, B.H.; Lee, C.W. Model Based Feed-forward Control of Electromagnetic Type Active Control Engine Mount System. J. Sound Vib. 2009, 323, 574–593. [CrossRef] Kitayama, F.; Hirata, K.; Asai, Y. Study on Active Control Engine Mount With Linear Oscillatory Actuator. In Proceedings of the 15th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering, Funchal, Madeira, 1–3 September 2011. Maqbool, H.F. Introduction. In Active Engine Mount System of a Vehicle; LAP LAMBERT Academic Publishing GmbH & Co. KG: Saarbrücken, Germany, 2012; pp. 6–13. Bu, Y.; Karasawa, M.; Isono, Y.; Mizuno, T. Proposal of highly effective driving method for linear oscillatory actuator. J. Optoelectron. Adv. Mater. 2008, 10, 1257–1261. Kitayama, F.; Hirata, K.; Sakai, M.; Yoshimoto, T. Linear Oscillatory Actuator Using Regenerative Energy. J. Jpn. Soc. Appl. Electromagn. Mech. 2013, 21, 413–418. [CrossRef] Ota, T.; Hirata, K.; Yamaguchi, T.; Kawase, Y.; Watanabe, K.; Nakase, A. Dynamic Response Analysis of Opening and Closing Sensor for Windows. IEEE Trans. Magn. 2005, 41, 1604–1607. [CrossRef] Hasegawa, Y.; Harada, K.; Ishihara, Y.; Todaka, T.; Hirata, K. Optimal design of axis symmetric linear oscillatory actuator using gemetic algorithm. Int. J. COMPEL 2000, 19, 626–631. Yamaguchi, T.; Kawase, Y.; Nakase, A.; Hirata, K.; Ota, T. Multi-motion Analysis of Opening and Closing Sensor for Windows Using 3-D Finite Element Method. IEEE Trans. Magn. 2006, 42, 1015–1018. [CrossRef] Kitayama, F.; Hirata, K.; Niguchi, N.; Kobayashi, M. Linear Oscillatory Actuator with Variable Characteristics using Two Sets of Coils. In Proceedings of the 17th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering, Valancia, Spain, 10–12 September 2015. © 2016 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons by Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/).
