CN1045327C - Vibration control device for sewing machine - Google Patents

Abstract

A vibration control device for a sewing machine capable of actively reducing the vibration generated on a bed of the sewing machine by the rotation of an arm shaft, the vertical reciprocation of a needle bar, and other vibration inducing movement without reducing a mechanical strength of the sewing machine and adopting any complex designs. The vibration control device includes a sync signal generating device for generating a sync signal in synchronism with rotation of the arm shaft, a vibration sensor for detecting vibration generated on the bed, a control unit for setting a transfer function, and a piezoelectric actuator for generating control vibration. A control signal interfering with the vibration detected by the vibration sensor is generated by the control unit so as to minimize a detection signal from the vibration sensor according to the sync signal, the detection signal, and the transfer function. Then, the piezoelectric actuator is operated according to the control signal to thereby generate the control vibration, thus actively reducing the detected vibration.

Description

The vibration control equipment of Sewing machines

The present invention relates to the vibration control equipment of Sewing machines, this equipment design is used for reducing effectively in fuselage by the rotation of arm power transmission shaft, the up-and-down movement of shank and the vibration that similar motion produces.

Vibrative technology in the various inhibition Sewing machiness has been proposed so far.Some typical technology are illustrated that with reference to Figure 11 Figure 11 represents the internal structure of Sewing machines fuselage in the prior art.

In first kind of technology, reduce shank 940 and be connected the oeverall quality of stub 946, so that reduce the vibration that produces by the up-and-down movement of shank 940 with the shank that is in vertical reciprocating motion with shank 940.For example the material with shank 940 changes the aluminum of hollow stem into by the steel material of solid round rod, so that reduce the quality of shank 940.

In second kind of technology, attempt the vibration that produces by rotation by the backguy bent axle 934 relevant with shank 940 and wire-drawing handle 936, elimination is by the vibration of the up-and-down movement generation of shank 940, the vibration that is produced by wire-drawing handle 936 swing is with the vibration by the motion generation of other parts relevant with shank 940 and wire-drawing handle 936.Determine material, size and the position of each parts, so that reduce vibration.

In the third technology, increase the wall thickness of arm 922, so that improve the rigidity of arm 922, thereby suppress generation of vibration.

In the 4th kind of technology, a kind of simple equipment is provided, the phase place of the waveform that it produces is opposite with the phase place of the waveform that shank 940 up-and-down movements produce, thereby suppresses the vibration of Sewing machines.

Yet in first kind of technology, the overall mechanical strength of mechanism has reduced.Therefore, for the reduction to mechanical strength limits, just will to quality reduce limit, so correspondingly limited reducing of vibration.

In second kind of technology, shank 940, wire-drawing handle 936 and other parts comprise the backguy bent axle 934 with parts 940,936 motions, produce very complicated relative motion at a high speed.Therefore, for reduce all parts of VIBRATION DESIGN fully reach balance be very the difficulty.

In the third technology, the cost of parts has improved.In addition, the rigidity of arm 922 improves, and makes the gross weight of Sewing machines increase, this with the weight that reduces Sewing machines, be convenient to the design idea that the operator uses and run in the opposite direction.

At last in the 4th kind of technology, the Oscillation Amplitude waveform identical, that phase place is opposite that wants very accurately to obtain to cause with the high speed rotation of the arm power transmission shaft 931 of Sewing machines is unusual difficulty.

In addition actually, the vibration of Sewing machines is interfered, the time-delay in the vibration transmission system and other be the very influence of complicated factors equally.Therefore, accurately follow the tracks of and suppress the vibration be considered to impossible.

An object of the present invention is to provide a kind of Sewing machines vibration control equipment, it can reduce in the Sewing machines fuselage effectively by the up-and-down movement of the rotation of arm power transmission shaft, shank and the similarly vibration that produces of high-speed motion, and can not reduce the mechanical strength of Sewing machines and/or needn't adopt complicated design.

In order to achieve the above object, the invention provides a kind of Sewing machines vibration control equipment, this Sewing machines has fuselage, sewing base, arm, arm power transmission shaft, shank, other mechanical part and electric part, it is characterized in that comprising: synchronization signal generation apparatus is used to produce the synchronous synchronizing signal of rotation with the arm power transmission shaft of Sewing machines; Vibration detection device is used to detect the vibration that produces on the fuselage of Sewing machines; The control vibration generating apparatus, it can produce the control vibration that is used to eliminate the vibration that produces on the fuselage; The transfer function setting device is used to preestablish the transfer function of the characteristic of the mechanical part of expression Sewing machines and electric parts; And vibration control apparatus, be used for control control vibration generating apparatus, so that the transfer function of setting according to the synchronizing signal that produces from synchronization signal generation apparatus, by the transfer function setting device and from the detection signal of vibration detection device reduces the vibration that is detected by vibration detection device to greatest extent.

In addition, the present invention also provides a kind of vibration control equipment of Sewing machines, this Sewing machines has fuselage, the base of sewing, have rotation the arm power transmission shaft arm and be installed in shank reciprocating in the arm, it is characterized in that comprising: synchronization signal generation apparatus is used to export the synchronous synchronizing signal of rotation with the arm power transmission shaft that rotates; Be installed at least one the vibration detection equipment on the fuselage, be used to detect vibration wherein; Be installed at least one the anti-oscillation actuator on the fuselage; And control device, be used for controlling the action of anti-oscillation actuator according to the output of the output of synchronization signal generation apparatus and vibration detection equipment.

According to Sewing machines vibration control equipment of the present invention with said structure, when the operation Sewing machines, produce synchronizing signal from synchronization signal generation apparatus, and detect in fuselage by the rotation of arm power transmission shaft, the up-and-down movement of shank and the vibration that similar motion produces by vibration detection device.Vibration control apparatus control control vibration generating apparatus, so that according to synchronizing signal, from the detection signal of vibration detection device and the transfer function of setting by the transfer function setting device, reduce vibration to greatest extent by the vibration detection device detection, so the control vibration that produces from the control vibration generating apparatus is used for eliminating the vibration that fuselage produces, and has so just reduced vibration effectively.In addition, even when the rotation of arm power transmission shaft is constant, and, also can follow the tracks of the vibration of this variable system reliably from the control vibration of control vibration generating apparatus, thereby reduce vibration because the vibration on thermal phenomenon, interference or the similar factor fuselage has changed.

Describe most preferred embodiment of the present invention with reference to the accompanying drawings in detail, in the accompanying drawing:

Fig. 1 is the perspective view of Sewing machines in first and second most preferred embodiments of the present invention;

Fig. 2 is the perspective view of the internal structure of the expression first most preferred embodiment middle machine body;

Fig. 3 is the block diagram of the vibration control system that comprises in the control box of the Sewing machines that links to each other with the essential part of fuselage;

Fig. 4 A is the schematic block diagram that produces the synchronizing signal generation equipment of synchronizing signal in first and second most preferred embodiments;

Fig. 4 B is the sequential chart from the synchronizing signal of the generation of the synchronizing signal generation equipment shown in Fig. 4 A;

Fig. 5 is the block diagram of sef-adapting filter in first most preferred embodiment;

Fig. 6 is the block diagram of the control module of vibration control system in first most preferred embodiment;

The block diagram that is used for the setting sequence of vibration control in first most preferred embodiment that Fig. 7 is with the essential part of fuselage links to each other;

Fig. 8 is the perspective view of the internal structure of the expression second most preferred embodiment middle machine body;

Fig. 9 is the block diagram of the connection state of the control box of Sewing machines in expression second most preferred embodiment;

Figure 10 is the block diagram of the vibration control system that comprises in the control box of second most preferred embodiment; And

Figure 11 is the perspective view of the internal structure of Sewing machines fuselage in the expression prior art.

Referring now to accompanying drawing most preferred embodiment of the present invention is described.

1 describe first most preferred embodiment of the present invention below with reference to accompanying drawings, Fig. 1 represents to use the outward appearance of Sewing machines of the present invention.Fuselage 16 has as lower part and the base 20 that contacts with oil vessel 12 with as the arm 22 on top.Fuselage 16 is installed on the oil vessel 12 by rubber vibration isolator 14, and oil vessel 12 is fixed on the workbench 10, and fuselage 16 drives by being fixed on workbench 10 following motor 18.Control box 80 be installed in motor 18 near.

Fig. 2 represents the internal structure and the belt pulley 30 of fuselage 16, and an end of the arm power transmission shaft 31 that provides in the arm 22 is provided belt pulley 30.Belt pulley 30 links to each other by belt 32 with motor 18 shown in Figure 1.The driving force of motor 18 sends arm power transmission shaft 31 to by belt 32 and belt pulley 30.

Backguy bent axle 34 is installed in the end away from the arm power transmission shaft 31 of belt pulley 30, rotates along with the rotation of arm power transmission shaft 31.Wire-drawing handle 36 links to each other with backguy bent axle 34, and along with the rotation of arm power transmission shaft 31 vertical oscillation.Shank 40 connects handle 44 by shank bent axle 42, shank and is connected stub 46 with shank and links to each other with wire-drawing handle 36, be fixed on the arm 22 under the guiding of shank sleeve pipe 50 and lower needle bar sleeve pipe 52, along with the rotation of arm power transmission shaft 31 is in vertical reciprocating motion.In the following description, the side that the Sewing machines of belt pulley 30 is installed will be called the right side, and a side of the Sewing machines of installation shank 40 will be called the left side.

The synchronizing signal of the synchronizing signal that the rotation of generation and arm power transmission shaft 31 is synchronous produces the right part that equipment 60 is installed in arm power transmission shaft 31.Narrow orifice plate 70, base slide plate 72 and be formed on the left part of base 20 as the vibrating sensor 82 of vibration detection equipment.Below parts 70,72 and 82, anti-oscillation actuator such as piezo-activator 74, a pair of helical spring 76 and weight 78 as the control vibration generating apparatus are arranged.The upper end of two springs 76 is installed to the lower surface of base 20 of the front and back position of base slide plate 72.Weight 78 is installed to the lower end of two springs 76, and passes through the flexiblely lower surface of vertical toward base 20 of two springs 76.Piezo-activator 74 inserts the lower surface of bases 20 and is between the upper surface of the weight 78 under the pressure of pulling force of spring 76.

Fig. 3 represents the structure of control box 80.Control box 80 and the vibrating sensor 82 that is used to detect residual vibration at the upper surface of base 20, the synchronizing signal that produces with the synchronous synchronizing signal of the rotation of arm power transmission shaft 31 produces equipment (synchronization signal generation apparatus) 60, and the piezo-activator 74 that produces the control vibration that is used to eliminate the vibration that produces on the base 20 links to each other.

When producing the synchronizing signal that equipment 60 produces and the rotation of arm power transmission shaft 31 is synchronous from synchronizing signal, this synchronizing signal inputs to sef-adapting filter 103 and control module 101 through amplifier 104, LPF (low pass filter) 105 that is used to remove high fdrequency component and A/D converter 106.On the other hand, detect the vibration of base 20 by vibrating sensor 82.Input to control module 101 from the detection signal of vibrating sensor 82 through amplifier 110, the HPF (high-pass filter) 111 that is used to remove DC component, LPF 112 and the A/D converter 113 that is used to remove high fdrequency component.Consider because the transmission characteristic that the variation of interference in the vibration path and the characteristic in these parts causes changes the transmission characteristic in control module 101 definite expression vibration paths and the transfer function of electric parts and mechanical part self character.According to transfer function, control module 101 determines to be applied to the transfer function of sef-adapting filter 103, so that reduce the detection signal from vibrating sensor 82 to greatest extent.The detection signal that reduces to greatest extent reflected in base 20 vibration that produces and the vibration that produces from piezo-activator 74 between the condition that influences each other.Control module 101 is set the control parameter that is used to specify the transfer function in the sef-adapting filter 103 then.In addition, control module 101 is proofreaied and correct the control parameter once in a while according to the variation of the characteristic of the variation of vibration transfer path and control system.

Correspondingly, the synchronizing signal that is produced by synchronizing signal generation equipment 60 inputs to sef-adapting filter 103 through amplifier 104, LPF105 and A/D converter 106.According to the transfer function that is applied to sef-adapting filter 103 from control module 101, the input signal that enters sef-adapting filter 103 is transformed into the data signal with given amplitude characteristic and given phase characteristic.This data signal is converted into analog signal through D/A converter 107, and the LPF 108 that is used to remove high fdrequency component carries out filtering, is amplified by amplifier 109, is applied to piezo-activator 74 as driving signal then.According to the driving signal that applies like this, piezo-activator 74 produces the control vibration of the vibration that is used for eliminating base 20.As a result, because the up-and-down movement and the similar kinetic vibration of the rotation of arm power transmission shaft 31, shank 40 are weakened in the position of vibrating sensor 82.

Fig. 4 (A) and 4 (B) expression is used to produce the notion that produces equipment 60 with the synchronizing signal of the synchronous synchronizing signal of the rotation of arm power transmission shaft 31 shown in Figure 3.Know that from vibration Frequency Analysis the vibration frequency on the base 20 is this fact of integral multiple of the speed of arm power transmission shaft 31.From this fact, consider to make the synchronizing signal process identical transmission system synchronous with the rotation of arm power transmission shaft 31, in base 20, can produce vibration.Therefore, shown in Fig. 4 (A) and 4 (B), by importing known code device signal and known clock signal, can obtain the signal synchronous (synchronizing signal) from the output that synchronizing signal produces equipment 60 with the rotation of arm power transmission shaft 31.Preset code device signal and clock signal, so arm power transmission shaft 31 whenever rotates a circle a just pulse of 24 of the output coder signal pulses and clock signal.When detecting falling pulse of code device signal during the clock signal high potential, synchronizing signal becomes high potential.Then, when detecting the 12 falling pulse of code device signal, synchronizing signal becomes electronegative potential.Then repeat this process, the synchronous synchronizing signal of rotation of output and arm power transmission shaft 31.In addition, remove the detection error of arm power transmission shaft 31 each rotations by clock signal.

By characteristic arbitrarily is provided, can be easily from the synchronizing signal synthetic control vibration that be used for drive pressure electric actuator 74 synchronous with the rotation of arm power transmission shaft 31.Owing to this reason, sef-adapting filter 103 shown in Figure 3 comprises qualification impulse response filter (also being the FIR wave filter) as shown in Figure 5.Output signal y (n) 305 from sef-adapting filter 103 is provided by following formula:

y(n)＝w0nx(n)+w1nx(n-1)+w2nx(n-2)+…+wMnx(n-M).

Input signal x (n) the 300th, the synchronizing signal shown in Fig. 4 (A) and 4 (B) from 60 outputs of synchronizing signal generation equipment; Unit time-delay of reference number 301 expressions; Reference number 303 be illustrated in the control module shown in Figure 3 101 accidental be updated and the variable filter coefficient w0n of therefrom transmission, w1n, w2n ..., wMn; Reference number 302 expression adders; And the branch number of reference number 306 expression wave filters.Employing variable filter coefficient w1n, w2n ..., wMn purpose be to follow the tracks of because the variation of the transmission characteristic that the characteristic changing of the interference in the vibration path and electric parts and mechanical part itself causes so that make the coefficient of wave filter converge to the optimum filter coefficient.

The structure of control module 101 as shown in Figure 6 so that recurrence estimation variable filter coefficient.In Fig. 6, produce reference signal C (n) through filtering wave by prolonging time device 402 by making synchronizing signal x (n).Reference signal C (n) and all import into adaptive algorithm parts 401 from the detection signal e (n) of vibrating sensor, so as by utilize lowest mean square (LMS) adaptive algorithm that provides by following formula upgrade variable filter coefficient w1n, w2n ..., wMn:

w(n)＝w(n-1)+μe(n)C(n)

Wherein, w (n)=[w1n, w2n ..., wMn] and t,

C(n)＝[c(n)，c(n-1)，…，c(n-M)]t，

C(n)＝h0x(n)+h1x(n-1)+…+hpx(n-p)

In above-mentioned equation, parameter μ is a constant that is called step size, and it is the parameter that the convergence rate of filter coefficient W (n) and convergence precision are exerted an influence.If parameter μ increases, then convergence rate (processing speed) improves, but convergence precision descends.On the contrary, if parameter μ reduces, then convergence precision improves, but convergence rate slows down.

Variable filter coefficient w1n, the w2n that obtains like this ..., wMn is sent to sef-adapting filter shown in Figure 5, produces output signal y (n) 305 according to the variable filter coefficient.Output signal y (n) 305 be a data signal it convert analog signal to by D/A converter 107.Then, this analog signal is amplified through amplifier 109 through LPF 108 filtering, and is applied to piezo-activator 74 as driving signal.Therefore, piezo-activator 74 produces the control vibration, eliminates because the vibration on the base 20 that 31 rotations of arm power transmission shaft cause.

The coefficient h 0 of filtering wave by prolonging time device 402 shown in Figure 6, h1 ..., hp is the fixed value that before obtained (referring to a kind of " Adaptive Signal Processing " of classification, B.Widrow and S.Stearns, Prentice-Hall 1985).Fig. 7 be expressed as the coefficient h 0 that obtains filtering wave by prolonging time device 402, h1 ..., hp the setting sequence.This setting sequence was carried out before producing above-mentioned control vibration, and was intended to obtain the transfer function from the control actuator, vibrating sensor 82 and the piezo-activator 74 that comprise circuit to vibrating sensor 82, so that reduce vibration.The sef-adapting filter FIR that adopts the LMS adaptive algorithm is mainly as sef-adapting filter 501.Signal produces source 502 and produces a periodic signal that is similar to the Sewing machines vibration.

The operation of setting sequence shown in Figure 7 is described now.Produce the periodic digital signal that source 502 one of output are similar to the Sewing machines vibration from signal.This signal through D/A converter 505, the LPF 506 and the amplifier 507 that are used to remove high fdrequency component be applied to piezo-activator 74, thereby drive pressure electric actuator 74 produces controlled vibration.On the other hand, the periodic digital signal that produces source 502 from signal inputs to sef-adapting filter 501, produces an output.Adder 503 will by vibrating sensor 82 detect and through amplifier 508, be used to remove the LPF 509 of high fdrequency component and vibration signal that A/D converter 510 applies and output addition from sef-adapting filter 501, thereby obtain error e (n) 504.Then, sef-adapting filter 501 recurrence are proofreaied and correct the coefficient of sef-adapting filter 501, so that reduce error e (n) 504 to greatest extent.The convergency value of coefficient finally as filter coefficient h0, h1 shown in Figure 6 ..., hp.

As mentioned above, the Sewing machines vibration control equipment of first most preferred embodiment has adopted conventional parts, does not increase any new parts and does not adopt the design of any complexity.Therefore, do not reduce the mechanical strength of Sewing machines, and kept the manufacturing cost of conventional fuselage.In this case, can reduce effectively because the vibration on the base that the arm power transmission shaft of Sewing machines rotates and the shank up-and-down movement causes.

In this most preferred embodiment, though shown vibrating sensor 82 is fixed on the ad-hoc location of base 20, it also can be mobilizable on base.In Sewing machines vibration control equipment according to first most preferred embodiment, single vibrating sensor 82 is provided on base 20, provide single piezo-activator 74 so that suppress the vibration of a position on the base 20.Yet because base 20 is not a rigid body, the vibration that therefore suppresses a position on the base 20 is not the vibration that can reduce whole base 20.As a result, the present invention has also comprised the Sewing machines vibration control equipment according to second most preferred embodiment, so that reduce the vibration of Sewing machines better.In other words, the vibration control equipment of design consideration second most preferred embodiment so that detect a plurality of locational Sewing machines vibrations, and suppresses a plurality of locational vibrations simultaneously.

Describe second most preferred embodiment in detail referring now to accompanying drawing.In second most preferred embodiment, for convenience of description for the purpose of, adopt two-channel vibrating functional sensor and binary channels piezo-activator.Yet present embodiment only needs at least two pairs of piezo-activators and sensor.In following description to second most preferred embodiment, the part identical with first most preferred embodiment will be represented with identical reference number, and omission is to their explanation.

As shown in Figure 8, below the left part of base 20, a piezo-activator 74A, a pair of helical spring 76A and a weight 78A of producing controlled vibration are provided.In addition, below the middle part of base 20, a piezo-activator 74B, a pair of helical spring 76B and a weight 78B of producing controlled vibration are provided.The upper end of helical spring 76A is at the lower surface of two fixed-site to base 20, and the upper end of helical spring 76B is also at the lower surface of two fixed-site to base 20.Weight 78A is installed to the lower end of helical spring 76A, and weight 78B is installed to the lower end of helical spring 76B.Weight 78A, 78B pass through the flexiblely lower surface of vertical toward base 20 of helical spring 76A, 76B respectively.Piezo-activator 74A inserts the lower surface of base 20 and is between the upper surface of pressure weight 78A down of pulling force of helical spring 76A, and the lower surface of piezo-activator 74B insertion base 20 and being between the upper surface of the weight 78B under the pressure of pulling force of helical spring 76B.In addition, two positions of corresponding respectively two piezo- activator 74A, 74B provide vibrating sensor 82A, the 82B that is used to detect residual vibration on base 20.

As shown in Figure 9, two vibrating sensor 82A, 82B of the control box 80 that comprises the Sewing machines vibration control system and the residual vibration of the upper surface that is used to detect base 20, the synchronizing signal that is used to produce with the synchronous synchronizing signal of the rotation of the arm power transmission shaft 31 of Sewing machines produces equipment 60, and is used to produce two piezo- activator 74A, 74B eliminating the control vibration that is created in the vibration on the base 20 and links to each other.Similar with first most preferred embodiment shown in Fig. 4 A, the 4B, produce and export synchronizing signal according to decoder signal and clock signal.

Figure 10 represents to be included in the structure of the vibration control system in the control box 80.Produce the synchronous synchronizing signal of rotation of equipment 60 generations and arm power transmission shaft 31 from synchronizing signal.This synchronizing signal converts data signal to by A/D converter 603 then by LPF 602 filtering that are used to remove high fdrequency component.After this, this data signal is input to sef-adapting filter 606 and digital filter 604.Consider to influence each other that digital filter 604 produces reference signal Y1m, and it is inputed to control module 605.

On the other hand, by the vibration on vibrating sensor 82A, the 82B detection base 20.From detection signal e1, the e2 of vibrating sensor 82A, 82B respectively through amplifier 607,610, be used to remove the LPF 608,611 of high fdrequency component, and the A/D converter 609,612 that is used for analog signal is transformed into data signal, input to control module 605.Consider because the change of the transmission characteristic that the variation of the characteristic in interference, electric parts and the mechanical part of vibration in the path and influencing each other causes, control module 605 is adjusted the coefficient of sef-adapting filter 606, so that specific transfer function is delivered to sef-adapting filter 606.More particularly, control module 605 determines to be applied to the transfer function of double-channel self-adapting wave filter 606, so that reduce detection signal simultaneously to greatest extent from vibrating sensor 82A, 82B, vibrating sensor 82A, 82B are used to detect the interactional condition between the vibration that produces on the base 20 and the control vibration that will produce from piezo- activator 74A, 74B, and control module 605 is set the control parameter for specifying the transfer function in the double-channel self-adapting wave filter 606.In addition, control module 605 is always proofreaied and correct the control parameter according to the change of the characteristic of variation in the vibration transfer path and control system.

Correspondingly, the synchronizing signal that is detected by synchronizing signal generation equipment 60 inputs to sef-adapting filter 606 through LPF 602 and A/D converter 603.According to the transfer function that is applied to double-channel self-adapting wave filter 606 from control module 605, the input signal that enters sef-adapting filter 606 is transformed into the data signal with given amplitude characteristic and given phase characteristic.Data signal y1 in the binary channels of sef-adapting filter 606, y2 are converted into analog signal through D/A converter 613,616, the LPF614,617 that is used to remove high fdrequency component carries out filtering, amplify by amplifier 615,618, be applied to piezo- activator 74A, 74B as driving signal then.Receive the piezo-activator 74A, the 74B that drive signal and produced the control vibration that elimination is created in the vibration on the base 20.As a result, because the up-and-down movement and the similar kinetic vibration of the rotation of arm power transmission shaft 31, shank 40 are weakened in the position of vibrating sensor 82A, 82B.

By characteristic arbitrarily is provided, can be easily from the synchronizing signal synthetic control vibration that be used for drive pressure electric actuator 74A, 74B synchronous with the rotation of arm power transmission shaft 31.Owing to this reason, double-channel self-adapting wave filter 606 shown in Figure 10 constitutes by limiting impulse response filter (also being the FIR wave filter).

Vibration control process in the present description control unit 605.

The vibration signal that makes e1 (n) expression detect by the 1st vibrating sensor 821, the vibration signal that d1 (n) expression is detected by the 1st vibrating sensor 821 when not producing the control vibration from piezo-activator, c1mj represents the j item of the transfer function c1m between m piezo-activator 74m and the 1st vibrating sensor 821, x (n) represents synchronizing signal, and Wmi represents to be used for input sync signal x (n) and drives i the coefficient of wave filter of each output channel of the sef-adapting filter 606 of m piezo-activator 74m.Under these conditions, provide following formula: $e_{1\left(n\right)}=d_{1\left(n\right)}-\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\underset{j=0}{\overset{J-1}{\mathrm{\Σ}}}{C}_{\mathrm{lmj}}\left(\underset{i=0}{\overset{l-1}{\mathrm{\Σ}}}{W}_{\mathrm{mi}}{X}_{(n-j-i)}\right)$ Equation 1

Wherein be designated as the sampling value of each representative of (n) down at n sample time; L represents the quantity (being two in second most preferred embodiment) of vibrating sensor; M represents the quantity (being two in second most preferred embodiment) of piezo-activator; The branch number of the transfer function c1m that the I representative is represented in Finite Impulse Response filter; And J represents the branch number of sef-adapting filter 606.

In equation 1, the parenthetic item representative that is included in the right side is imported the output of wave filter when (coefficient of this wave filter is represented by Wm) of each output channel in the sef-adapting filter 606 into when synchronizing signal; From m piezo-activator 74m, export as vibrational energy by transfer function and the parenthetic item that is included in the right side signal energy that the item representative of expression advances m piezo-activator 74m when input that multiplies each other, and a signal when the vibration transfer function c1m on base 20 transfers to the 1st vibrating sensor 821 then; And, promptly arrive the subordinate vibration sum of the 1st vibrating sensor 821 in the item representative that is right after symbol "-" on right side signal sum from 1 vibrating sensor 821 of whole piezo-activators to the.

So, provide the characterisitic function that following formula is represented: $J_e=\underset{I=1}{\overset{L}{\mathrm{\Σ}}}\{e_{1\left(n\right)}{\}}^2$ Equation 2

Filter coefficient for the minimum of a value that obtains asking characterisitic function Je has adopted the LMS adaptive algorithm in second most preferred embodiment.In other words, characterisitic function Je (equation 2) is approximately equal to the instantaneous slope value (equation 3) of each filter coefficient Wmi, and each filter coefficient Wmi is upgraded by this instantaneous slope value.

In other words, obtain equation 3 from equation 2: $(\▿J_e)W_{\mathrm{mi}}=\underset{j=0}{\overset{J-I}{\mathrm{\Σ}}}{2e}_{1\left(n\right)}\left({\▿e}_{1\left(n\right)}\right)W_{\mathrm{mi}}$ Equation 3

Further, obtain equation 4 from equation 1: $(\▿e_{1\left(n\right)})W_{\mathrm{mi}}=-\underset{I=1}{\overset{L}{\mathrm{\Σ}}}{C}_{\mathrm{Imj}}{X}_{(n-j-i)}=-{\mathrm{\γ}}_{\mathrm{In}}(n-i)$ Equation 4

By replace the right side of equation 4 with r1m (n-i), filter coefficient can be represented by equation 5:

W _mi(n+1)＝W _mi(n)-μ(J _e)W _mi $=W_{\mathrm{mi}}\left(n\right)+2\mathrm{\μ}\underset{I=1}{\overset{L}{\mathrm{\Σ}}}{e}_{1\left(n\right)}{\mathrm{\γ}}_{\mathrm{Im}}(n-i)$ Equation 5

Wherein parameter μ is a constant that is called step size, and it is the parameter that the convergence rate of sef-adapting filter and convergence precision are exerted an influence.If parameter μ increases, then convergence rate (processing speed) improves, but convergence precision descends.On the contrary, if parameter μ reduces, then convergence precision improves, but convergence rate slows down.

The coefficients w 1n that more than obtains, w2n ..., wMn is sent to sef-adapting filter 606, produces output data signal y1 (n) and y2 (n).Output data signal y1 (n) and y2 (n) convert analog signal to by D/A converter 613,616, through LPF614,617 filtering, amplify through amplifier 615,617, are applied to piezo- activator 74A, 74B as driving signal then.Then, piezo- activator 74A, 74B receive this driving signal, produce the control vibration, eliminate because arm power transmission shaft 31 rotations and comprise vibration on the base 20 that the vibration of motion causes.

Obtain the coefficient c1mj of digital filter shown in Figure 10 604 earlier, so that obtain mutual transfer function, so that reduce vibration from the control actuator, vibrating sensor 82A, 82B and piezo-activator 74A, the 74B that comprise circuit to vibrating sensor 82A, 82B.Digital filter 604 mainly is the FIR wave filter.

The operation of second most preferred embodiment is described now.When motor 18 began to rotate, code device signal and clock signal were input to synchronizing signal and produce equipment 60, and then synchronizing signal produces synchronizing signal x of equipment 60 outputs.Synchronizing signal x offers the vibration control system that is included in the control box 80.

In vibration control system, synchronizing signal x delivers to digital filter 604 and sef-adapting filter 606 through LPF 602, A/D converter 603.Digital filter 604 is according to the transfer function c1m between each vibrating sensor 82A, 82B and each piezo-activator 74A, the 74B, based on equation 4, utilize the synchronizing signal x of input to calculate synchronizing signal r1m, then to control module 605 output synchronizing signal r1m.

On the other hand, vibrating sensor 82A, 82B detect the locational residual vibration at them, and the output of the vibration control system in control box 80 is corresponding to error signal e 1, the e2 of residual vibration.In vibration control system, the error signal e 1 of input, e2 are respectively through amplifier 607,610, and EPF 608,611 and A/D converter 609,612 transfer to control module 605.

In control module 605, utilize each input signal to calculate according to equation 5, upgrade filter coefficient.In other words, current sample time, the filter coefficient Wmi (n) of n was updated, so characterisitic function Je is promptly minimized corresponding to all sides from the error signal e 1 (n) of the residual vibration of vibrating sensor 82A, 82B, so that obtain the filter coefficient Wmi (n+1) that sets in sample time (n+1).Then, control module 605 is to the control signal of sef-adapting filter 606 outputs according to calculated value Wmi (n+1).Therefore, the coefficient of each wave filter in the sef-adapting filter 606 is updated to the filter coefficient Wmi of new calculating in sample time (n+1).By this way, filter coefficient was repeatedly upgraded in the fixing sampling period, so that try to achieve the minimum of a value Je of the characterisitic function in the control module 605.

Each wave filter in the sef-adapting filter 606 carries out vector calculus to the synchronizing signal x of input with at the filter coefficient Wmi that sets sometime, so that obtain output valve y1, y2, then output valve y1, y2 are as driving signal respectively through D/A converter 613,616, and LPF 614,617 and amplifier 615,618 are delivered to piezo- activator 74A, 74B.

Correspondingly, piezo- activator 74A, 74B produce the control vibration according to input signal y1, y2, then in base 20, propagate each the vibration output that so produces corresponding to the transfer function c1m of estimation in advance, so that form vibration.As a result, after the control convergence, almost eliminated vibration in the regional area on the residing base 20 of vibrating sensor 82A, 82B by controlled vibration, thereby greatly reduced residual vibration.Even when the rotation owing to motor 18 made that vibration changes, this change also can be followed the tracks of reliably and detect by synchronizing signal x, therefore reduced vibration reliably.

In second most preferred embodiment, though shown vibrating sensor 82A, 82B are fixed on the base 20, it also can be mobilizable on base 20.In addition, though two vibrating sensor 82A, 82B and two piezo- activator 74A, 74B are provided in second most preferred embodiment, the quantity of vibrating sensor and piezo-activator is not limited to this.Three vibrating sensors and three piezo-activators for example can be provided.

Claims (20)

1. Sewing machines vibration control equipment, this Sewing machines have fuselage, sewing base, arm, arm power transmission shaft, shank, other mechanical part and electric part, it is characterized in that comprising:

Synchronization signal generation apparatus is used to produce the synchronous synchronizing signal of rotation with the arm power transmission shaft of described Sewing machines;

Vibration detection device is used to detect the vibration that produces on the fuselage of described Sewing machines;

The control vibration generating apparatus, it can produce the control vibration that is used to eliminate the vibration that produces on the described fuselage;

The transfer function setting device is used to preestablish the transfer function of the characteristic of the mechanical part of the described Sewing machines of expression and electric parts; And

Vibration control apparatus, be used to control described control vibration generating apparatus, so that the transfer function of setting according to the synchronizing signal that produces from described synchronization signal generation apparatus, by described transfer function setting device and from the detection signal of described vibration detection device reduces the vibration that is detected by described vibration detection device to greatest extent.

2. according to the Sewing machines vibration control equipment of claim 1, it is characterized in that described vibration detection device comprises a plurality of vibration detection devices that detect the vibration that is created in a plurality of positions on the described fuselage simultaneously, described control vibration generating apparatus comprises a plurality of control vibration generating apparatus that are used to produce the control vibration of eliminating the vibration that is created in the described a plurality of positions on the described fuselage simultaneously, and described vibration control apparatus controls described a plurality of control vibration generating apparatus, so that reduce the vibration that detected by described a plurality of vibration detection devices simultaneously to greatest extent.

3. according to the Sewing machines vibration control equipment of claim 2, it is characterized in that on the base of described fuselage, providing described vibration detection device and described control vibration generating apparatus.

4. according to the Sewing machines vibration control equipment of claim 3, it is characterized in that described vibration detection device is supported on the upper surface of described base, and described control vibration generating apparatus inserts under pressure between the weight of the lower surface of described base and the described lower surface that elasticity is pressed to described base.

5. according to the Sewing machines vibration control equipment of claim 1, it is characterized in that described vibration detection device comprises a plurality of vibration detection devices that detect the vibration that is created in a plurality of positions on the described fuselage simultaneously.

6. according to the Sewing machines vibration control equipment of claim 1, it is characterized in that described control vibration generating apparatus comprises a plurality of control vibration generating apparatus that are used to produce the control vibration of eliminating the vibration that is created in the described a plurality of positions on the described fuselage simultaneously.

7. the vibration control equipment of a Sewing machines, this Sewing machines has fuselage, the base of sewing, have rotation the arm power transmission shaft arm and be installed in shank reciprocating in the arm, it is characterized in that comprising:

Synchronization signal generation apparatus is used to export the synchronous synchronizing signal of rotation with the arm power transmission shaft that rotates;

Be installed at least one the vibration detection equipment on the fuselage, be used to detect vibration wherein;

Be installed at least one the anti-oscillation actuator on the fuselage; And

Control device is used for controlling according to the output of the output of described synchronization signal generation apparatus and described vibration detection equipment the action of described anti-oscillation actuator.

8. according to the vibration control equipment of claim 7, it is characterized in that further comprising the transfer function setting device, be used to preestablish the transfer function of the characteristic of the mechanical part of expression Sewing machines and electric parts.

9. vibration control equipment according to Claim 8 is characterized in that further comprising compensation arrangement, is used to provide the adjustment parameter that is applied on described at least one anti-oscillation actuator.

10. vibration control equipment according to Claim 8 is characterized in that having at least two described vibration detection equipment and described anti-oscillation actuator.

11. vibration control equipment according to Claim 8 is characterized in that at least one vibration detection equipment has a fixed position on the sewing base.

12. vibration control equipment according to Claim 8 is characterized in that described at least one vibration detection equipment can be positioned at any position on the sewing base.

13. vibration control equipment according to Claim 8 is characterized in that the described anti-oscillation actuator that is installed on the sewing base comprises:

From the suspended weight of sewing base;

Resilient suspension arrangement between sewing base and described weight is used to hang described weight; And

Actuator between described weight and sewing base.

14. according to the vibration control equipment of claim 13, it is characterized in that described resilient suspension arrangement comprises a pair of spring, a described spring centered spring is installed on the described weight, therefore be separated from each other, and the most described weight pulls to the sewing base.

15., it is characterized in that described anti-oscillation actuator is positioned at the centre of described spring according to the vibration control equipment of claim 14.

16., it is characterized in that described anti-oscillation actuator is a piezo-activator according to the vibration control equipment of claim 14.

17., it is characterized in that described control device starts described anti-oscillation actuator according to the vibration from described vibration detection equipment input according to the vibration control equipment of claim 15.

18. Sewing machines vibration control equipment according to Claim 8 is characterized in that described at least one vibration detection equipment comprises a plurality of vibration detection equipment that detect the vibration that is created in a plurality of positions on the described fuselage simultaneously.

19. Sewing machines vibration control equipment according to Claim 8 is characterized in that described anti-oscillation actuator comprises a plurality of anti-oscillation actuator that is used to produce the control vibration of eliminating the vibration that is created in the described a plurality of positions on the described fuselage simultaneously.

20. Sewing machines vibration control equipment according to Claim 8, it is a pair of to it is characterized in that anti-oscillation actuator and vibration detection equipment become, so that it is right to form vibration suppression.

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