阅读说明：本技术 一种压电双晶片电荷驱动电路 (A kind of piezoelectric bimorph charge driving circuit ) 是由 潘成亮 戴天亮 石超 于连栋 夏豪杰 李维诗 胡民港 丰安辉 于 2019-09-11 设计创作，主要内容包括：本发明公开了一种压电双晶片电荷驱动电路,涉及压电精密驱动控制领域,压电双晶片的上层和下层电压片分别与传感电容串联设置在高压直流正负电源之间,高压放大器的输出端连接压电双晶片的中间公共电极,传感电容精确感知上层和下层压电片的电荷,并通过隔离放大器和差动放大器处理后与控制信号源比较,反馈控制压电双晶片的电荷差值。本发明简化压电双晶片的驱动电路,降低控制系统成本,避免反向电压驱动,利用电荷驱动方法极大提高了压电双晶片弯曲位移的控制精度。(The invention discloses a kind of piezoelectric bimorph charge driving circuits, it is related to Precision Piezoelectric drive control field, the upper and lower voltage piece of piezoelectric bimorph is arranged in series between high voltage direct current positive-negative power respectively with sensing capacitance, the intermediate public electrode of the output end connection piezoelectric bimorph of high-voltage amplifier, sensing capacitance accurately perceives the charge on upper layer and lower layer's piezoelectric patches, and after being handled by isolated amplifier and differential amplifier compared with controlling signal source, the charge difference of feedback control piezoelectric bimorph.The present invention simplifies the driving circuit of piezoelectric bimorph, reduces control system cost, avoids backward voltage from driving, greatly improve the control precision of piezoelectric bimorph bending displacement using charge driving method.)

1. a kind of piezoelectric bimorph charge driving circuit, it is characterised in that: including piezoelectric bimorph, sensing capacitance A, sensing capacitance B, high voltage direct current positive supply, high voltage direct current negative supply, high-voltage amplifier, isolated amplifier A, isolated amplifier B, differential amplifier With control signal source；

The upper layer piezoelectric patches of the piezoelectric bimorph connects high voltage direct current positive electricity after connecting by its top electrode with sensing capacitance A Source, lower layer's piezoelectric patches of the piezoelectric bimorph connect high voltage direct current negative supply after connecting by its lower electrode with sensing capacitance B, Upper layer piezoelectric patches connects the output end of high-voltage amplifier with the intermediate public electrode of lower layer piezoelectric patches；

The input terminal of the isolated amplifier A is connect with sensing capacitance A, the input terminal and sensing capacitance B of the isolated amplifier B Connection；

The input terminal of the differential amplifier is connect with the output end of isolated amplifier A and isolated amplifier B respectively；

The input terminal of the high-voltage amplifier is connect with the output end of control signal source and differential amplifier respectively.

2. a kind of piezoelectric bimorph charge driving circuit according to claim 1, it is characterised in that: the piezoelectric bimorph Using polarization direction from the top down.

3. a kind of piezoelectric bimorph charge driving circuit according to claim 1, it is characterised in that: the sensing capacitance A The polystyrene capacitor of high-precision High Linear is respectively adopted with sensing capacitance B, its capacitance of the two is piezoelectric bimorph chip capacitor 10~100 times of amount.

Technical field

The present invention relates to Precision Piezoelectric drive control fields, and in particular to a kind of piezoelectric bimorph charge driving circuit.

Background technique

Piezoelectric actuator utilizes the inverse piezoelectric effect of piezoelectric material, and the electric field by being applied to material internal causes in material The strain in portion or stress, to form the deformational displacement or driving force of piezoelectric actuator macroscopic view.Piezoelectric actuator has displacement point Resolution is high, driving force is big, fast response time, not by electromagnetic interference the advantages that, be widely used in biologic medical, materials chemistry, object Manage the application of the fields nanometer positionings such as electronics operation.

Piezoelectric bimorph is the most common Piezoelectric Driving structure, utilizes the non-equilibrium flexible strain of the upper and lower piezoelectric patches (layer piezoelectric patches elongation as above, lower layer's piezoelectric patches shorten), the Bending Deformation for forming piezoelectric bimorph is displaced, simple with structure, The features such as deformational displacement is big.Since piezoelectric bimorph includes at least two piezoelectric patches, and the internal electric intensity applied is different, on Layer and lower layer's piezoelectric patches need two high-voltage amplifiers to respectively drive, and control difficulty and system cost is higher.In order to reduce driving The complexity of circuit, patent No. US5233256 propose to drive jointly by the single high-voltage amplifier of optimization electrode connection realization, but Since piezoelectric actuator need to avoid excessive reverse drive voltages, effective drive voltage range of this method is restricted.In order to Expand the range of driving voltage, patent No. CN108258931A proposes to change the upper and lower pressure by diode and parallel resistance The driving voltage ratio of electric piece, but due to the impedance operator of parallel resistance and capacitor, effective driving frequency range of this method by To limitation.

In addition, there is the non-linear relations such as sluggishness, creep, piezoelectricity between the driving voltage and deformational displacement of piezoelectric actuator Restriction of the Bit andits control precision of driver by voltage control method.Due between the charge and deformational displacement of piezoelectric actuator There are preferable linear relationships, and the displacement of piezoelectric actuator is greatly improved using charge driving circuit substitution Voltag driving circuit Control precision.However, being suitable for piezoelectric bimorph since there are structure and characteristic differences for Voltag driving circuit and charge driving circuit The Voltag driving circuit of piece cannot be simply converted to charge driving circuit, and existing Voltag driving circuit is asked there is also many Topic.The characteristics of therefore, it is necessary to further combined with piezoelectric bimorph and charge driving circuit, proposes simpler, accurate, effective Piezoelectric bimorph charge driving circuit and control method.

Summary of the invention

It is an object of the invention to overcome the deficiencies of the prior art and provide a kind of piezoelectric bimorph charge driving circuit, To solve the technical problems such as piezoelectric bimorph driving circuit structure complexity, low precision in the prior art.

The present invention is achieved by the following technical solutions:

The present invention provides a kind of piezoelectric bimorph charge driving circuits, including piezoelectric bimorph, sensing capacitance A, sensing Capacitor B, it high voltage direct current positive supply, high voltage direct current negative supply, high-voltage amplifier, isolated amplifier A, isolated amplifier B, differential puts Big device and control signal source；

The upper layer piezoelectric patches of the piezoelectric bimorph is connecting high voltage direct current just after connecting by its top electrode with sensing capacitance A Power supply, lower layer's piezoelectric patches of the piezoelectric bimorph connect high voltage direct current negative electricity after connecting by its lower electrode with sensing capacitance B The intermediate public electrode of source, upper layer piezoelectric patches and lower layer piezoelectric patches connects the output end of high-voltage amplifier；

The input terminal of the isolated amplifier A is connect with sensing capacitance A, the input terminal and sensing of the isolated amplifier B Capacitor B connection；

The input terminal of the differential amplifier is connect with the output end of isolated amplifier A and isolated amplifier B respectively；

The input terminal of the high-voltage amplifier is connect with the output end of control signal source and differential amplifier respectively.

Further, the piezoelectric bimorph is using polarization direction from the top down.

Further, the polystyrene capacitor of high-precision High Linear is respectively adopted in the sensing capacitance A and sensing capacitance B, Its capacitance of the two is 10~100 times of piezoelectric bimorph capacitance.

The present invention has the advantage that compared with prior art

(1) the upper and lower voltage piece of piezoelectric bimorph is arranged in series in the positive negative electricity of high voltage direct current with sensing capacitance respectively Between source, it is only necessary to which the intermediate public electrode of a high-voltage amplifier connection piezoelectric bimorph passes through the electricity of intermediate public electrode Pressure adjusts the charge difference of the upper and lower piezoelectric patches, simplifies driving circuit, reduces control system cost, while avoiding reversely driving The influence of dynamic voltage.

(2) sensing capacitance of high-precision High Linear is used, and sets suitable capacitance ratio between piezoelectric patches, smaller The lower accurate perception upper layer and lower layer's piezoelectric patches of partial pressure loss charge, and then handled by isolated amplifier and differential amplifier Afterwards compared with controlling signal source, the charge difference of feedback control piezoelectric bimorph, to improve bending displacement control precision.Together When, avoid the charge of sensing capacitance by the influence of subsequent process circuit using isolated amplifier.

Detailed description of the invention

Fig. 1 is the schematic illustration of piezoelectric bimorph charge driving circuit of the present invention；

Fig. 2 is the structural schematic diagram of piezoelectric bimorph of the present invention；

Fig. 3 is the relational graph of piezoelectric bimorph charge and voltage of the present invention；

Fig. 4 is the relational graph of piezoelectric bimorph charge and displacement of the present invention；

Fig. 5 is the waveform diagram of present invention control signal source voltage and piezoelectric bimorph charge；

Fig. 6 is lagging characteristics figure of the piezoelectric bimorph of the present invention under charge and voltage driving.

Specific embodiment

Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete Site preparation description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.It is based on Embodiment in the present invention, it is obtained by those of ordinary skill in the art without making creative efforts every other Embodiment shall fall within the protection scope of the present invention.

As shown in Figs. 1-2, a kind of piezoelectric bimorph charge driving circuit, including piezoelectric bimorph 1, sensing capacitance A2-1, Sensing capacitance B2-2, high voltage direct current positive supply 3, high voltage direct current negative supply 4, high-voltage amplifier 5, isolated amplifier A6-1, isolation Amplifier B6-2, differential amplifier 7 and control signal source 8；

The upper layer piezoelectric patches 1-1 of the piezoelectric bimorph 1 connects high after being connected by its top electrode a with sensing capacitance A2-1 After pressing DC positive power 3, the lower layer piezoelectric patches 1-2 of the piezoelectric bimorph 1 to connect by its lower electrode b with sensing capacitance B2-2 High voltage direct current negative supply 4 is connected, upper layer piezoelectric patches 1-1 connects high-voltage amplifier with the intermediate public electrode c of lower layer piezoelectric patches 1-2 5 output end；

The input terminal of the isolated amplifier A6-1 is connect with sensing capacitance A2-1, and the charge of upper layer piezoelectric patches 1-1 is believed Number amplification output, the input terminal of the isolated amplifier B6-2 is connect with sensing capacitance B2-2, by the charge of lower layer piezoelectric patches 1-2 Signal amplification output；

The input terminal of the differential amplifier 7 connects with the output end of isolated amplifier A6-1 and isolated amplifier B6-2 respectively It connects, the charge difference signal of upper layer piezoelectric patches 1-1 and lower layer piezoelectric patches 1-2 is amplified and exported；

The input terminal of the high-voltage amplifier 5 is connect with the output end of control signal source 8 and differential amplifier 7 respectively, structure At negative feedback control loop, the error signal for controlling signal source 8 and differential amplifier 7 is amplified into output；

The piezoelectric bimorph 1 is using polarization direction from the top down；

The sensing capacitance A2-1 and sensing capacitance B2-2 is respectively adopted the polystyrene capacitor of high-precision High Linear, and two Its capacitance of person is 10~100 times of 1 capacitance of piezoelectric bimorph.

In the present embodiment, piezoelectric patches 1-1 in upper layer is identical with the specification of lower layer piezoelectric patches 1-2, sensing capacitance A2-1 and biography The specification that electrification holds B2-2 is identical, and isolated amplifier A6-1 is identical with the specification of isolated amplifier B6-2.

Specific work process and principle:

As shown in figure 3, in the actual application of piezoelectric bimorph, due to the nonlinear characteristic of voltage driving, piezoelectricity The actual capacitance of each piezoelectric patches changes with driving voltage in twin lamella 1, the voltage U of each piezoelectric patches_P, reference capacitance C_PAnd electricity Lotus Q_PBetween relationship may be expressed as:

Q_P=U_P(1+δ)C_P (1)

Wherein δ is the variable for describing piezoelectric patches lagging characteristics.

As shown in figure 4, between the charge and deformational displacement of piezoelectric actuator, there are preferable linear relationship, piezoelectric bimorphs 1 Bending Deformation displacement x_PWith the quantity of electric charge Q of upper layer piezoelectric patches 1-1₁With the quantity of electric charge Q of lower layer piezoelectric patches 1-2₂Difference Q₂-Q₁It Between relationship are as follows:

x_P=α (Q₂-Q₁) (2)

Wherein α is constant.

As shown in Figs. 1-2, the capacitor of sensing capacitance A2-1 and sensing capacitance B2-2 are constant C_S, upper layer piezoelectric patches 1-1 Voltage be U_P1, the voltage of upper layer sensing capacitance A2-1 is U_S1, the voltage of lower layer piezoelectric patches 1-2 is U_P2, lower layer's sensing capacitance The voltage of B2-2 is U_S2, then the charge Q of upper layer piezoelectric patches 1-1₁With the charge Q of lower layer piezoelectric patches 1-2₂It respectively indicates are as follows:

Wherein δ₁And δ₂The variable of upper layer piezoelectric patches 1-1 and lower layer's piezoelectric patches 1-2 lagging characteristics are respectively described.

The voltage of high voltage direct current positive supply 3 and high voltage direct current negative supply 4 is respectively V_CCAnd V_SS, the output of high-voltage amplifier 5 Voltage is U_o, voltage V_CC、V_SSAnd U_oMeet relational expression:

It can be obtained by formula 4, the output voltage U of high-voltage amplifier 5_oIt indicates are as follows:

If the gain of isolated amplifier A6-1 and isolated amplifier B6-2 are 1, the gain of differential amplifier 7 is constant K_S, then the output voltage △ U of differential amplifier 7_SIt indicates are as follows:

The open-loop gain of high-voltage amplifier 5 is K, and the voltage of control signal source 8 is U_i, then the output of high-voltage amplifier 5 is electric Press U_oIt is also denoted as:

U_o=K (U_i-△U_S) (7)

It can be obtained by formula 5 and 7, the charge difference of piezoelectric bimorph 1 may be expressed as:

When parameter meets:

The charge difference of piezoelectric bimorph 1 is about are as follows:

It can be obtained by formula 2 and 10, the Bending Deformation displacement x of piezoelectric bimorph 1_PIt may be expressed as:

Wherein α, C_SAnd K_SFor constant, i.e. the Bending Deformation displacement x of piezoelectric bimorph 1_PWith the voltage U of control signal source 8_i Meet linear relationship.

As shown in figure 5, as the voltage U for controlling signal source 8 in initial situation_iWhen being zero, the charge Q of upper layer piezoelectric patches 1-1₁ With the charge Q of lower layer piezoelectric patches 1-2₂Equal, upper layer piezoelectric patches 1-1 and lower layer bi-morph piezo-electric twin lamella 1-2 generate balance and answer Become, piezoelectric bimorph 1 does not bend；With voltage U_iIncrease, upper layer piezoelectric patches 1-1 is because of charge Q₁Increase and shortens, lower layer Piezoelectric patches 1-2 is because of charge Q₂Reduce and extend, piezoelectric bimorph 1 is bent upwards deformation；With voltage U_iReduction, upper layer piezoelectricity Piece 1-1 is because of charge Q₁Reduce and extend, lower layer piezoelectric patches 1-2 is because of charge Q₂Increase and shorten, piezoelectric bimorph 1 is turned under curved Become.

As shown in fig. 6, the charge difference Q of piezoelectric bimorph 1₂-Q₁With the voltage U of control signal source 8_iVariation and holding Linear relationship, to accurately control the Bending Deformation displacement x of piezoelectric bimorph 1_P, test result show charge driving under sluggishness Sluggishness under comparison with voltage driving improves significantly.