CN205315593U - Tunable frequency rank ladder beam formula dynamic vibration absorber based on piezoelectricity feedback control - Google Patents

Abstract

The utility model provides a tunable frequency rank ladder beam formula dynamic vibration absorber based on piezoelectricity feedback control, this structure actuates unit, signal amplification circuit and power amplifier by base, single -order ladder beam, piezoelectric sensor unit, piezoelectricity and constitutes. The lower extreme of base is fixed in inhales the object that shakes, and the base upper end is fixed with single -order ladder beam one end. Piezoelectric sensor unit and piezoelectricity actuate the unit and all paste on single -order ladder beam surface, and the shape that piezoelectric sensor unit and piezoelectricity actuated the unit all is isosceles triangle, and they highly equal moreover, and the signal amplification circuit input is connected to the electrode of piezoelectric sensor unit, and the power amplifier input is connected to the signal amplification circuit output, and the power amplifier output is connected piezoelectricity and is actuated the unit electrode. The utility model discloses an adjustment signal amplification circuit's the gain rigidity that can adjust the cantilever beam to adjust the frequency of bump leveller. The utility model discloses do not need mechanical drive, simple structure, job stabilization, power control is convenient, quick.

Description

A kind of frequency-adjustable ladder beam-type dynamic vibration absorber based on piezoelectricity feedback control

Technical field

The utility model belongs to mechanical vibration antivibration area, and what be specifically related to is a kind of frequency-adjustable ladder beam-type dynamic vibration absorber based on piezoelectricity feedback control.

Background technology

The vibration equipment that dynamic vibration absorber can effectively suppress change of frequency less, owing to structure is simple, relative low price is implemented with being easy to, and is widely applied in the vibration control of mechanical engineering, aerospace, traffic and transport field, has become one of important means of control vibration at present. When the natural frequency of dynamic vibration absorber equals external excitation frequency, it is possible to much slower is by the vibration of control structure.

Dynamic vibration absorber generally can be divided into passive type and the big class of semi-active type two. Wherein passive type dynamic vibration absorber can only be used for controlling the vibration of specific a certain frequency range, and it effectively controls frequency range relative narrower. When external excitation frequency is away from dynamic vibration absorber natural frequency, passive type dynamic vibration absorber will lose efficacy. In order to widen the controlled frequency scope of dynamic vibration absorber, it is possible to by regulating rigidity or the quality of bump leveller so that the natural frequency of bump leveller can change with the change of external excitation frequency, and the dynamic vibration absorber of this kind of frequency-adjustable is called as semi active vibration absorber.

Current semi active vibration absorber can be divided into manual type, mechanical type, electromagnetic type and magnetic current change etc. Manual type bump leveller regulates quality block position on a cantilever beam by manual type, realize the adjustment (Zhao Cunsheng of bump leveller frequency, Li Haifeng, Zhu Shijian, the theoretical analysis of socle girder dynamic vibration absorber and test, noise and vibration control, 2015,35 (4): 175-178). Owing to adopting manual mode, not too convenient in using so actual.

Mechanical type semi active vibration absorber generally regulates quality block position or spring rigidity by stepper-motor, thus regulate bump leveller frequency (Xu Zhenbang, Gong Xinglong, Chen Xianmin, Ni Zhengchao, mechanical from the research of tuner-type dynamic vibration absorber, China's mechanical engineering, 2009,20 (9): 1057-1062).This kind of semi active vibration absorber needs mechanical actuation device, structure relative complex.

By regulating, received current changes ELECTROMAGNETIC STIFFNESS to electromagnetic type semi active vibration absorber, thus realize change (the stone Sunyu of bump leveller frequency, Zhou Xubin, Shen Junfeng, yellow person of outstanding talent, spacecraft electromagnetism frequency conversion bump leveller performance analysis and test, noise and vibration control, 2015,35 (5): 60-64); Magnetic current becomes semi active vibration absorber, and by regulating, received current changes the rigidity of magnetic rheology elastic body, thus regulate bump leveller frequency (Li Qingyun, separate faithful and upright, Yang Zhirong, tower Na, rich pillar, the experiment of magnetic rheology elastic body dynamic vibration absorber, noise and vibration control, 2015,35 (4): 138-142). But there is electromagnetic leakage phenomenon in this two classes bump leveller.

Needing mechanical actuation device, complex structure for above-mentioned semi active vibration absorber, there is the shortcomings such as electromagnetic leakage phenomenon, a kind of structure of the utility model offer is simple, frequency adjustment semi active vibration absorber easily.

Summary of the invention

The utility model object is to provide that a kind of structure is simple, the frequency-adjustable ladder beam-type dynamic vibration absorber of frequency adjustment piezoelectricity feedback control easily.

In order to achieve the above object, the utility model adopts following technical scheme: a kind of frequency-adjustable ladder beam-type dynamic vibration absorber based on piezoelectricity feedback control, it is characterized in that, it is made up of base, single Stepped Beam, piezoelectric sensing unit, piezoelectric actuating unit, signal amplification circuit and power amplifier. The lower end of base is fixed on absorbing object, and base upper end is fixed with single Stepped Beam one end. Piezoelectric sensing unit and piezoelectric actuating unit are pasted onto single Stepped Beam surface, the Electrode connection signal amplification circuit input terminus of piezoelectric sensing unit, signal amplification circuit output terminal connects power amplifier input terminus, power amplifier output terminal connects the electrode of piezoelectric actuating unit, forms complete loop. Being amplified the gain of circuit by conditioning signal, thus change the voltage at piezoelectric actuating unit two ends, due to inverse piezoelectric effect, the voltage change at piezoelectric ceramic piece two ends causes socle girder rigidity to change, it is achieved the adjustment of bump leveller frequency.

The cross section of single Stepped Beam described in the utility model is rectangle.

Single Stepped Beam described in the utility model is fixed by welding or screw and base.

Piezoelectric sensing unit described in the utility model can be that piezoelectricity film or piezoelectric ceramics are formed.

Piezoelectric actuating unit described in the utility model can be that monolithic piezoelectric ceramic material or the above piezoceramic material of two panels are laminated.

The shape of piezoelectric sensing unit described in the utility model and piezoelectric actuating unit is all isosceles triangle, and length is equal.

The base of piezoelectric sensing unit described in the utility model and piezoelectric actuating unit is all positioned at single Stepped Beam and base inboardend.

Piezoelectric sensing unit described in the utility model and piezoelectric actuating unit can be pasted onto Stepped Beam upper surface simultaneously, it is possible to be pasted onto Stepped Beam lower surface simultaneously, it is possible to be pasted onto upper surface and the lower surface of Stepped Beam respectively.

In signal amplification circuit described in the utility model, gain can regulate.

Advantage of the present utility model is: the utility model structure is simple, it is not necessary to how mechanical drive, it is only necessary to amplified the gain of circuit and the natural frequency of adjustable bump leveller by conditioning signal, so the utility model response is fast, and reliability height.

Accompanying drawing explanation

Fig. 1 is the model schematic of the frequency-adjustable ladder beam-type dynamic vibration absorber based on piezoelectricity feedback control described in the utility model.

Fig. 2 is the virtual support analogy figure of the frequency-adjustable ladder beam-type dynamic vibration absorber based on piezoelectricity feedback control described in the utility model.

In the drawings, base is (1), single Stepped Beam is (2), piezoelectric sensing unit is (3), piezoelectric actuating unit is (4), signal amplification circuit for (5) and power amplifier be (6).

Embodiment

In conjunction with Fig. 1 and 2, illustrate below in conjunction with accompanying drawing and the utility model is done more detailed description: based on the frequency-adjustable ladder beam-type dynamic vibration absorber of piezoelectricity feedback control, it is characterized in that, it is made up of base (1), single Stepped Beam (2), piezoelectric sensing unit (3), piezoelectric actuating unit (4), signal amplification circuit (5) and power amplifier (6); The lower end of base (1) is fixed on absorbing object, and base (1) upper end is fixed with single Stepped Beam (2) one end; Piezoelectric sensing unit (3) and piezoelectric actuating unit (4) are pasted onto single Stepped Beam (2) surface, and the shape of piezoelectric sensing unit and piezoelectric actuating unit is all isosceles triangle, and length is equal; The base of piezoelectric sensing unit and piezoelectric actuating unit is all positioned at single Stepped Beam and base inboardend; Electrode connection signal amplification circuit (5) input terminus of piezoelectric sensing unit (3), signal amplification circuit (5) output terminal connects power amplifier (6) input terminus, power amplifier (6) output terminal connects the electrode of piezoelectric actuating unit (4), forms complete loop. As shown in Figure 1.

As preferred implementation of the present utility model, the distance between described base upper end and single Stepped Beam ladder is the 80%-90% of single Stepped Beam length.

As preferred implementation of the present utility model, the base width of described piezoelectric sensing unit and piezoelectric actuating unit is the 40%-45% of single Stepped Beam width, the length of described piezoelectric sensing unit and piezoelectric actuating unit is the 40%-50% of single Stepped Beam length, and the thickness of described piezoelectric sensing unit and piezoelectric actuating unit is between 0.2mm-2mm.

Principle of work of the present utility model is as follows:

Described dynamic vibration absorber is fixed on absorbing object, by document (MaoQ, PietzkoS.ControlofNoiseandStructuralVibration.London:Spr inger.2013) it will be seen that the output signal Q of piezoelectric sensing unit can represent is

$Q=\frac{h+h_f}{2}{\∫}_0^{L_p}F\left(x\right)\·\left(e_{31}\frac{{\∂}^{2}w\left(x\right)}{\∂x^2}\right)dx---\left(1\right)$

In formula, h is the thickness of the sub-beam in piezoelectric sensing unit place, h_fFor the thickness of piezoelectric sensing unit, e₃₁For the piezo-electric modulus of piezoelectric sensing unit. W (x) is for beam is at x point and by the relative displacement between control structure. The shape function that F (x) is piezoelectric sensing unit. L_pFor the length of piezoelectric sensing unit.

Formula (1) is carried out twice integration respectively, can obtain

$\begin{array}{c}Q=\frac{h+h_s}{2}{e}_{31}\left(F\right(x)\frac{\∂w\left(x\right)}{\∂x}{|}_0^{L_p}-{\∫}_0^{x_p}\frac{\∂F\left(x\right)}{\∂x}\frac{\∂w\left(x\right)}{\∂x}dx)\\ =\frac{h-h_s}{2}{e}_{31}\left(F\right(x)\frac{\∂w\left(x\right)}{\∂x}{|}_0^{L_p}-\frac{\∂F\left(x\right)}{\∂x}w(x){|}_0^{L_p}+{\∫}_0^{x_p}\frac{{\∂}^{2}F\left(x\right)}{\∂x^2}w(x\left)dx\right)\end{array}---\left(2\right)$

Owing to described piezoelectric sensing unit is isosceles triangle, so shape function F (x) can represent it is,

$F\left(x\right)=\frac{W_p}{L_p}(L_p-x)---\left(3\right)$

In formula, W_pFor the width on piezoelectric sensing unit base.

Can find from formula (3)

$F(x=L_p)=\frac{{\∂}^{2}F\left(x\right)}{\∂x^2}=0---\left(4\right)$

Notice that the base of described piezoelectric sensing unit is all positioned at single Stepped Beam and base inboardend, it means that relative displacement and the strain on piezoelectric sensing unit base are zero. That is,

$w(x=0)=\frac{\∂w(x=0)}{\∂x}=0---\left(5\right)$

Wushu (4) and (5) substitute into formula (2), then the output signal of piezoelectric sensing unit can represent and is,

$Q=\frac{h+h_s}{2}{e}_{31}\frac{W_p}{L_p}w\left(L_p\right)\∝w\left(L_p\right)---\left(6\right)$

Can finding from formula (6), the output signal of described piezoelectric sensing unit is directly proportional to the displacement on piezoelectric sensing unit summit. Owing to piezoelectric actuating cell configuration is identical with piezoelectric sensing unit, and the base of piezoelectric actuating unit is also positioned at single Stepped Beam and base inboardend, according to inverse piezoelectric effect, the effect of the piezoelectric actuating unit of isosceles triangle is equivalent to apply the some power being directly proportional to its input voltage on its summit, namely

F(L_p)=Hu (7)

In formula, H is a real constant, and its value can be determined according to the material behavior of piezoelectric actuating unit and size thereof.

The output signal of piezoelectric sensing unit is input to signal amplification circuit, is then input to power amplifier, and power amplifier output terminal connects the electrode of piezoelectric actuating unit, drives piezoelectric actuating unit, forms complete feedback control system. Owing to piezoelectric sensing unit and piezoelectric actuating unit contraposition are arranged, so this feedback control system is unconditional stability system. The control voltage u at piezoelectric actuating unit two ends can represent,

U=Gain B Q=Gain B Kw (L_p)(8)

In formula,Gain is the gain of signal amplification circuit, and B is power amplifier gain.

Wushu (8) substitutes into formula (7) and can obtain,

F(L_p)=Gain HBKw (L_p)(9)

Can finding from formula (9), the control direct ratio of piezoelectric actuating unit and the displacement on its summit, described feedback control system is equivalent to arrange a virtual spring at piezoelectric actuating unit apex, and the rigidity of this virtual spring is Gain HBK, as shown in Figure 2. Owing to coefficient H, B, K are real constant, so amplified the gain G ain of circuit by conditioning signal, namely can change the Stepped Beam rigidity of bump leveller, thus regulate the natural frequency of described bump leveller.

Claims (8)

1. based on the frequency-adjustable ladder beam-type dynamic vibration absorber of piezoelectricity feedback control, it is characterized in that, it is made up of base (1), single Stepped Beam (2), piezoelectric sensing unit (3), piezoelectric actuating unit (4), signal amplification circuit (5) and power amplifier (6); The lower end of base (1) is fixed on absorbing object, and base (1) upper end is fixed with single Stepped Beam (2) one end; Piezoelectric sensing unit (3) and piezoelectric actuating unit (4) are pasted onto single Stepped Beam (2) surface, Electrode connection signal amplification circuit (5) input terminus of piezoelectric sensing unit (3), signal amplification circuit (5) output terminal connects power amplifier (6) input terminus, power amplifier (6) output terminal connects the electrode of piezoelectric actuating unit (4), forms complete loop.

2. as claimed in claim 1 based on the frequency-adjustable ladder beam-type dynamic vibration absorber of piezoelectricity feedback control, it is characterised in that, the cross section of single Stepped Beam (2) is rectangle or square.

3. as claimed in claim 1 based on the frequency-adjustable ladder beam-type dynamic vibration absorber of piezoelectricity feedback control, it is characterised in that, piezoelectric sensing unit (3) is that piezoelectricity film or piezoelectric ceramics are formed.

4. as claimed in claim 1 based on the frequency-adjustable ladder beam-type dynamic vibration absorber of piezoelectricity feedback control, it is characterised in that, piezoelectric actuating unit (4) is that monolithic piezoelectric ceramic material or the above piezoceramic material of two panels are laminated.

5. as claimed in claim 1 based on the frequency-adjustable ladder beam-type dynamic vibration absorber of piezoelectricity feedback control, it is characterised in that, the shape of piezoelectric sensing unit (3) and piezoelectric actuating unit (4) is all isosceles triangle, and length is equal.

6. as claimed in claim 1 based on the frequency-adjustable ladder beam-type dynamic vibration absorber of piezoelectricity feedback control, it is characterised in that, the base of piezoelectric sensing unit (3) and piezoelectric actuating unit (4) is all positioned at Stepped Beam and base inboardend.

7. as claimed in claim 1 based on the frequency-adjustable ladder beam-type dynamic vibration absorber of piezoelectricity feedback control, it is characterized in that, piezoelectric sensing unit (3) and piezoelectric actuating unit (4) can be pasted onto Stepped Beam upper surface simultaneously, or be pasted onto Stepped Beam lower surface, or it is pasted onto upper surface and the lower surface of Stepped Beam respectively simultaneously.

8. as claimed in claim 1 based on the frequency-adjustable ladder beam-type dynamic vibration absorber of piezoelectricity feedback control, it is characterised in that, in signal amplification circuit (5), gain can regulate.