阅读说明：本技术 一种高可靠性压电指向调节机构及其实现方法 (High-reliability piezoelectric directional adjusting mechanism and implementation method thereof ) 是由 田征 徐明龙 周建 于 2021-08-24 设计创作，主要内容包括：压电指向调节机构在卫星激光通信、激光武器、天文光学观测领域广泛应用,由于使用条件特殊,对产品的寿命和可靠性提出极高需求。本发明针对现有压电指向调节机构单个压电堆工作电压较高,由于单个压电堆击穿导致整个机构失效的缺点,提出一种高可靠性压电指向调节机构及其实现方法,通过压电堆串联安装之后再进行差分驱动的工作方式,实现压电堆工作电压、工作电流、热耗大幅降低,压电堆工作寿命大幅度提高。通过在所有压电堆表面粘接电阻应变片,组成应变全桥来实现偏转角度的测量。当偏转轴下某一压电堆击穿或某一偏转轴向下不同压电支撑单元各有一个压电堆击穿时,驱动单元和应变测量单元仍能够正常工作,提高产品的可靠性。(The piezoelectric pointing adjusting mechanism is widely applied to the fields of satellite laser communication, laser weapons and astronomical optical observation, and has special use conditions, so that extremely high requirements are provided for the service life and the reliability of products. The invention provides a high-reliability piezoelectric pointing adjusting mechanism and an implementation method thereof, aiming at the defects that the working voltage of a single piezoelectric stack of the conventional piezoelectric pointing adjusting mechanism is higher and the whole mechanism fails due to the breakdown of the single piezoelectric stack. The surface of all piezoelectric stacks is bonded with a resistance strain gauge to form a strain full bridge to realize the measurement of the deflection angle. When a certain piezoelectric stack under a deflection shaft is broken down or when one piezoelectric stack breaks down in different piezoelectric support units under a deflection shaft, the driving unit and the strain measurement unit can still work normally, and the reliability of the product is improved.)

1. The utility model provides a directional adjustment mechanism of high reliability piezoelectricity which characterized in that: the piezoelectric actuator comprises an integrated shell (1) containing a flexible ring, wherein the integrated shell (1) containing the flexible ring and a base (6) are concentrically installed and fixedly connected, a first piezoelectric driving unit (3), a second piezoelectric driving unit (12), a third piezoelectric driving unit (13) and a fourth piezoelectric driving unit (2) are fixed on the base (6), and are fixedly bonded in an array manner by 90 degrees around the center of a circle of an installation surface on the base; the structure of the first piezoelectric driving unit (3), the second piezoelectric driving unit (12), the third piezoelectric driving unit (13) and the fourth piezoelectric driving unit (2) are the same, and the first piezoelectric driving unit (3) comprises a first buffer ball (3.1), a first metal gasket (3.2), a first resistance strain gage (3.3), a second resistance strain gage (3.4), a first piezoelectric stack (3.5), a third resistance strain gage (3.6), a fourth resistance strain gage (3.7) and a second piezoelectric stack (3.8); the internal connection relation of the first piezoelectric driving unit (3) is as follows: the first buffer ball (3.1) is connected with the integrated machine shell (1) containing the flexible ring, the position of the first buffer ball is restrained by a conical groove in the integrated machine shell (1) containing the flexible ring, the first buffer ball (3.1) is in contact with the first metal gasket (3.2) through the installation stress of the integrated machine shell containing the flexible ring, the first resistance strain gauge (3.3) and the second resistance strain gauge (3.4) are adhered to two opposite smooth surfaces of the first piezoelectric stack (3.5) and are centrally adhered, and the third resistance strain gauge (3.6) and the fourth resistance strain gauge (3.7) are adhered to two opposite smooth surfaces of the second piezoelectric stack (3.8) and are centrally adhered; the first piezoelectric stack (3.5) and the second piezoelectric stack (3.8) are arranged in a stacked manner, and two electrode surfaces are aligned;

the deflection direction of the working output of the first piezoelectric driving unit (3) and the third piezoelectric driving unit (13) is an X axis, and the deflection direction of the second piezoelectric driving unit (12) and the fourth piezoelectric driving unit (2) is a Y axis.

2. A high reliability piezoelectric pointing adjusting mechanism according to claim 1, wherein: the integrated shell (1) containing the flexible ring is concentrically mounted with the base (6) through the first positioning pin (5), the second positioning pin (7) and the third positioning pin (10), and is connected and fixed with the base through the first set screw (4), the second set screw (8), the third set screw (9) and the fourth set screw (11).

3. A high reliability piezoelectric pointing adjusting mechanism according to claim 1, wherein: a conical hole is formed in the integrated shell (1) containing the flexible ring, and the positioning mode corresponds to four piezoelectric driving units arranged on the base one by one.

4. A high reliability piezoelectric pointing adjusting mechanism according to claim 1, wherein: driving signals of X-axis and Y-axis two-dimensional deflection are independently controlled, and the wiring modes of X-axis and Y-axis double-axis driving circuits are the same; two driving units under the same deflection axis X or Y are driven differentially, a piezoelectric stack layer for driving in each piezoelectric driving unit is arranged, and the two laminated piezoelectric stacks are electrically connected in series;

the positive electrode of a first piezoelectric stack (3.5) of the first piezoelectric driving unit (3) is connected with a fixed high-voltage signal + HV, the negative electrode of the first piezoelectric stack (3.5) is connected with the positive electrode of a second piezoelectric stack (3.8), the negative electrode of the second piezoelectric stack (3.8) is connected with an external driving signal Vin _ X, the negative electrode of the second piezoelectric stack (3.8) is simultaneously connected with the positive electrode of a fifth piezoelectric stack (13.4) in another piezoelectric driving unit under the same deflection axis, namely a third piezoelectric driving unit (13), the negative electrode of the fifth piezoelectric stack (13.4) is connected with the positive electrode of a sixth piezoelectric stack (13.7), the negative electrode of the sixth piezoelectric stack (13.7) is connected with a fixed negative signal-HV, the external driving signal Vin _ X is controlled to change from-HV to + HV, differential driving of the two driving units under X is realized, and deflection around the X axis is realized;

the electrical connection mode of the Y-axis lower piezoelectric drive unit is similar to that of the X-axis, the anode of a third piezoelectric stack (12.5) of the second piezoelectric drive unit (12) is connected with a fixed high-voltage signal + HV, the cathode of the third piezoelectric stack (12.5) is connected with the anode of a fourth piezoelectric stack (12.8), the cathode of the fourth piezoelectric stack (12.8) is connected with an external drive signal Vin _ Y, the cathode of the fourth piezoelectric stack (12.8) is simultaneously connected with the anode of a seventh piezoelectric stack (2.4) in another piezoelectric drive unit under the same deflection axis, namely the fourth piezoelectric drive unit (2), the cathode of the seventh piezoelectric stack (2.4) is connected with the anode of an eighth piezoelectric stack (2.7), and the cathode of the eighth piezoelectric stack (2.7) is connected with a fixed negative signal-HV; and controlling the external driving signal Vin _ Y to change between-HV and + HV, realizing differential driving of two driving units under Y, and realizing deflection around the Y axis.

5. A high reliability piezoelectric pointing adjusting mechanism according to claim 1, wherein: the X-axis deflection measurement strain bridge comprises a first resistor (R1), a second resistor (R2), a third resistor (R3), a fourth resistor (R4), a fifth resistor (R5), a sixth resistor (R6), a seventh resistor (R7) and an eighth resistor (R8) which are sequentially connected in series; the indirect voltage negative pole of a second resistor (R2) and a third resistor (R3), the indirect voltage negative pole of a sixth resistor (R6) and a seventh resistor (R7), the indirect bridge circuit excitation voltage positive pole of the first resistor (R1) and an eighth resistor (R8), and the indirect bridge circuit excitation voltage negative pole of a fourth resistor (R4) and a fifth resistor (R5);

when deflection around an X axis is measured, a first resistance strain gauge (3.3), a second resistance strain gauge (3.4), a third resistance strain gauge (3.6), a fourth resistance strain gauge (3.7) on a first piezoelectric driving unit (3), a ninth resistance strain gauge (13.3), a tenth resistance strain gauge (13.4), an eleventh resistance strain gauge (13.6) and a twelfth resistance strain gauge (13.7) on a third piezoelectric driving unit (13) form an X axis deflection measurement strain bridge, the first resistance strain gauge (3.3) is located at a first resistance (R1) position, the second resistance strain gauge (3.4) is located at a sixth resistance (R6) position, the third resistance strain gauge (3.6) is located at a second resistance (R2) position, the fourth resistance strain gauge (3.7) is located at a fifth resistance (R5) position, the ninth resistance strain gauge (13.3) is located at a third resistance (R3) position, the eighth resistance strain gauge (R8) is located at a tenth resistance (R8) position, the eleventh resistance strain gauge (13.6) is located at the fourth resistance (R4) position and the twelfth resistance strain gauge (13.7) is located at the seventh resistance (R7) position; the electrical connection positions of the resistance strain gauges on the same bridge arm can be interchanged.

When deflection around the Y axis is measured, a Y-axis deflection measuring strain bridge consisting of a resistance strain gauge on the second piezoelectric driving unit (12) and a resistance strain gauge on the fourth piezoelectric driving unit (2), and the composition of the Y-axis deflection measuring strain bridge and the corresponding relation between the Y-axis deflection measuring strain bridge and the resistance strain gauges on the second piezoelectric driving unit (12) and the fourth piezoelectric driving unit (2) are the same as the X-axis deflection measuring strain bridge.

6. An operating method of a high-reliability piezoelectric direction adjusting mechanism according to any one of claims 1 to 5, characterized in that: each piezoelectric driving unit is formed by connecting two piezoelectric stacks in series, is used as one piezoelectric stack and adopts a differential connection mode; controlling the driving control signal Vin _ X or Vin _ Y to realize the control of the X-axis or Y-axis output deflection angle; the voltage cathode and voltage anode access points and the specific numerical values are matched and determined according to the specification of the selected piezoelectric stack;

the strain measurement bridge circuit with the X axis or the Y axis composed of the resistance strain gauge can measure the deflection angle, and the X axis bridge circuit and the Y axis bridge circuit are relatively independent electrically; when the driving control voltage changes, the voltage of the strain full-bridge circuit also changes, and after the relation between the output signal of the strain full-bridge circuit and the deflection angle of the mechanism is calibrated, the deflection angle of an X axis or a Y axis is measured through the strain full-bridge circuit.

7. The method for realizing high reliability of the high reliability piezoelectric direction adjusting mechanism according to any one of claims 1 to 5, wherein: the method comprises the following specific steps: two piezoelectric stack layers of each piezoelectric driving unit are arranged, and two electrode surfaces are arranged in an aligned mode, so that the failure mode of a mechanism or an associated driving circuit caused by breakdown of a single piezoelectric stack is effectively avoided;

the two piezoelectric stacks of each piezoelectric driving unit are connected in series, the voltage on each piezoelectric stack is one half of the total voltage of the piezoelectric driving unit without the series design during normal work, the working voltage of the piezoelectric stacks is reduced, and the service life of the piezoelectric stacks can be greatly prolonged;

pasting a strain gauge on the surface of the piezoelectric stack, wherein the strain output of the strain gauge strictly corresponds to the driving voltage on the piezoelectric stack; when one piezoelectric stack breaks down, a short circuit appears between the piezoelectric stack electrodes, the surface resistance strain gauge does not have strain output, the piezoelectric driving unit still has one piezoelectric stack to work, the driving voltage of the piezoelectric driving unit is unchanged, the voltage on the piezoelectric stack which still normally works is twice of the driving voltage before the fault, and the strain output is also twice of the driving voltage before the fault. Therefore, when one piezoelectric stack under any shaft fails, the strain bridge can still work and is matched with the drive control circuit to realize high-precision pointing adjustment;

two piezoelectric stacks located in different piezoelectric driving units are broken down and fail under an X axis or a Y axis, a strain gauge on the surface of the failed piezoelectric stack outputs without strain, the driving voltage of the other piezoelectric stack of the piezoelectric driving unit is increased by two times, the output strain of the strain gauge is also increased by two times before failure, the piezoelectric directional adjusting mechanism can still realize deflection work, and the output stroke, the measuring function and the performance are not affected.

Technical Field

The invention belongs to the field of light beam adjustment control, and particularly discloses a high-reliability piezoelectric pointing adjusting mechanism and an implementation method thereof.

Background

The beam-pointing adjustment mechanism typically drives a mirror to effect reflective adjustment of the beam, also commonly referred to as a fast-reflecting mirror. Common driving elements of the pointing adjustment mechanism are piezoelectric ceramics and voice coil motors, and can be classified into a piezoelectric type pointing adjustment mechanism and an electromagnetic type pointing adjustment mechanism according to the types of the driving elements. The piezoelectric type pointing mechanism has the advantages of small size, high pointing accuracy, light weight, small heat productivity and the like, and is widely applied. The conventional piezoelectric directional adjusting mechanism selects piezoelectric stacks with different strokes according to the required deflection range. Taking a piezoelectric fine pointing mechanism supported by four points as an example, two piezoelectric stacks are needed for single-axis deflection, and deflection around a certain axis is realized in a differential driving mode of the two piezoelectric stacks. Through the double-shaft decoupling on the structural design, the four piezoelectric stacks can realize the two-dimensional deflection of the mechanism.

The piezoelectric stack is a capacitive load, and the failure mode of the piezoelectric stack is mainly characterized by the breakdown of the piezoelectric stack, and the failure of the piezoelectric stack usually causes the short circuit of a power driving circuit. The existing piezoelectric fine pointing mechanism, namely a three-point supporting or four-point supporting two-dimensional pointing adjusting mechanism and a two-point supporting one-dimensional adjusting pointing adjusting mechanism, loses the adjusting capability once the piezoelectric stack fails in electric breakdown. Due to the short circuit of the circuit, the overcurrent and even damage of the driver are often caused. The piezoelectric directional adjusting mechanism is often applied to high-precision optical systems, such as satellite laser communication terminals and astronomical optical imaging stabilizing systems, the products have almost no maintainability, and extremely high reliability requirements are provided for used directional adjusting products. However, the existing design of the piezoelectric beam adjustment mechanism is difficult to ensure high reliability, and therefore, breakdown failure of a single piezoelectric stack may be costly. The existing piezoelectric pointing adjusting mechanism usually adopts an integral backup mode, so that the mass and the volume of a system in which the piezoelectric pointing adjusting mechanism is arranged, the development cost of a driving circuit and control software are increased, and the piezoelectric pointing adjusting mechanism is not allowed under the condition of limitation of factors such as certain space or weight.

Disclosure of Invention

In order to make up for the above disadvantages of the existing piezoelectric direction adjusting mechanism, the invention provides a high-reliability piezoelectric direction adjusting mechanism and an implementation method thereof, which can effectively improve the reliability of products.

In order to achieve the purpose, the invention adopts the following technical scheme:

a high-reliability piezoelectric pointing adjusting mechanism comprises an integrated shell 1 containing a flexible ring, wherein the integrated shell 1 containing the flexible ring and a base 6 are concentrically installed and fixedly connected, a first piezoelectric driving unit 3, a second piezoelectric driving unit 12, a third piezoelectric driving unit 13 and a fourth piezoelectric driving unit 2 are fixed on the base 6 and are bonded and fixed in an array mode by 90 degrees around the circle center of an installation surface on the base; the first piezoelectric driving unit 3, the second piezoelectric driving unit 12, the third piezoelectric driving unit 13 and the fourth piezoelectric driving unit 2 have the same structure, and the first piezoelectric driving unit 3 comprises a first buffer ball 3.1, a first metal gasket 3.2, a first resistance strain gage 3.3, a second resistance strain gage 3.4, a first piezoelectric stack 3.5, a third resistance strain gage 3.6, a fourth resistance strain gage 3.7 and a second piezoelectric stack 3.8; the internal connection relationship of the first piezoelectric driving unit 3 is as follows: the first buffer ball 3.1 is connected with the integrated machine shell 1 with the flexible ring, the position of the first buffer ball is restrained by a conical groove in the integrated machine shell 1 with the flexible ring, the first buffer ball 3.1 is in contact with the first metal gasket 3.2 through the installation stress of the integrated machine shell with the flexible ring, the first resistance strain gauge 3.3 and the second resistance strain gauge 3.4 are adhered to two smooth surfaces opposite to the first piezoelectric stack 3.5 and are centrally adhered, and the third resistance strain gauge 3.6 and the fourth resistance strain gauge 3.7 are adhered to two smooth surfaces opposite to the second piezoelectric stack 3.8 and are centrally adhered; the first piezoelectric stack 3.5 and the second piezoelectric stack 3.8 are arranged in a laminated manner, and two electrode surfaces are aligned;

the deflection direction of the working output of the first piezoelectric driving unit 3 and the third piezoelectric driving unit 13 is an X axis, and the deflection direction of the second piezoelectric driving unit 12 and the fourth piezoelectric driving unit 2 is a Y axis.

The integrated shell 1 containing the flexible ring is concentrically mounted with the base 6 through the first positioning pin 5, the second positioning pin 7 and the third positioning pin 10, and is connected and fixed with the base through the first set screw 4, the second set screw 8, the third set screw 9 and the fourth set screw 11.

The integrated shell 1 containing the flexible ring is internally provided with a taper hole, and the positioning mode corresponds to four piezoelectric driving units arranged on the base one by one.

Driving signals of X-axis and Y-axis two-dimensional deflection are independently controlled, and the wiring modes of X-axis and Y-axis double-axis driving circuits are the same; two driving units under the same deflection axis X or Y are driven differentially, and piezoelectric stacks arranged on each driving lamination are connected in series;

the positive electrode of a first piezoelectric stack 3.5 of the first piezoelectric driving unit 3 is connected with a fixed high-voltage signal + HV, the negative electrode of the first piezoelectric stack 3.5 is connected with the positive electrode of a second piezoelectric stack 3.8, the negative electrode of the second piezoelectric stack 3.8 is connected with an external driving signal Vin _ X, the negative electrode of the second piezoelectric stack 3.8 is simultaneously connected with the positive electrode of 13.4 of a fifth piezoelectric stack in another piezoelectric driving unit under the same deflection shaft, namely a third piezoelectric driving unit 13, the negative electrode of 13.4 of the fifth piezoelectric stack is connected with the positive electrode of a sixth piezoelectric stack 13.7, and the negative electrode of 13.7 of the sixth piezoelectric stack is connected with a fixed negative signal-HV; controlling the external driving signal Vin _ X to change between-HV and + HV, realizing the differential driving of two driving units under X, and realizing the deflection around the X axis;

the electrical connection mode of the Y-axis down-pressure electric drive unit is similar to that of the X-axis, the anode of a third piezoelectric stack 12.5 of the second piezoelectric drive unit 12 is connected with a fixed high-voltage signal + HV, the cathode of the third piezoelectric stack 12.5 is connected with the anode of a fourth piezoelectric stack 12.8, the cathode of the fourth piezoelectric stack 12.8 is connected with an external drive signal Vin _ Y, the cathode of the fourth piezoelectric stack 12.8 is simultaneously connected with the anode of 2.4 of a seventh piezoelectric stack in another piezoelectric drive unit under the same deflection axis, namely the fourth piezoelectric drive unit 2, the cathode of 2.4 of the seventh piezoelectric stack is connected with the anode of 2.7 of the eighth piezoelectric stack, and the cathode of 2.7 of the eighth piezoelectric stack is connected with a fixed negative signal-HV; and controlling the external driving signal Vin _ Y to change between-HV and + HV, realizing differential driving of two driving units under Y, and realizing deflection around the Y axis.

The eight resistance strain gauges of the two piezoelectric stacks under the X axis form an X-axis deflection measurement strain full bridge, and the X-axis deflection measurement strain bridge comprises a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and an eighth resistor R8 which are sequentially connected in series; the indirect voltage negative pole of a second resistor R2 and a third resistor R3, the indirect voltage negative pole of a sixth resistor R6 and a seventh resistor R7, the indirect bridge circuit excitation voltage positive pole of a first resistor R1 and an eighth resistor R8, and the indirect bridge circuit excitation voltage negative pole of a fourth resistor R4 and a fifth resistor R5;

when measuring deflection around the X axis, a first resistance strain gage 3.3, a second resistance strain gage 3.4, a third resistance strain gage 3.6, a fourth resistance strain gage 3.7 on the first piezoelectric driving unit 3 and a ninth resistance strain gage 13.3 on the third piezoelectric driving unit 13, an X-axis deflection measurement strain bridge is formed by a tenth resistance strain gauge 13.4, an eleventh resistance strain gauge 13.6 and a twelfth resistance strain gauge 13.7, the first resistance strain gauge 3.3 is located at the position of a first resistor R1, the second resistance strain gauge 3.4 is located at the position of a sixth resistor R6, the third resistance strain gauge 3.6 is located at the position of a second resistor R2, the fourth resistance strain gauge 3.7 is located at the position of a fifth resistor R5, the ninth resistance strain gauge 13.3 is located at the position of a third resistor R3, the tenth resistance strain gauge 13.4 is located at the position of an eighth resistor R8, the eleventh resistance strain gauge 13.6 is located at the position of a fourth resistor R4, and the twelfth resistance strain gauge 13.7 is located at the position of a seventh resistor R7; the electrical connection positions of the resistance strain gauges on the same bridge arm can be interchanged.

When the deflection around the Y axis is measured, a Y-axis deflection measuring strain bridge consisting of the resistance strain gauge on the second piezoelectric driving unit 12 and the resistance strain gauge on the fourth piezoelectric driving unit 2 is measured, and the composition of the Y-axis deflection measuring strain bridge and the corresponding relation between the resistance strain gauge on the second piezoelectric driving unit 12 and the resistance strain gauge on the fourth piezoelectric driving unit 2 are the same as the X-axis deflection measuring strain bridge.

According to the working method of the high-reliability piezoelectric direction adjusting mechanism, each piezoelectric driving unit is formed by connecting two piezoelectric stacks in series and is used as one piezoelectric stack in a differential wiring mode; controlling the driving control signal Vin _ X or Vin _ Y to realize the control of the X-axis or Y-axis output deflection angle; the voltage cathode and voltage anode access points and the specific numerical values are matched and determined according to the specification of the selected piezoelectric stack;

the strain measurement bridge circuit with the X axis or the Y axis composed of the resistance strain gauge can measure the deflection angle, and the X axis bridge circuit and the Y axis bridge circuit are relatively independent electrically; when the driving control voltage changes, the voltage of the strain full-bridge circuit also changes, and after the relation between the output signal of the strain full-bridge circuit and the deflection angle of the mechanism is calibrated, the deflection angle of an X axis or a Y axis is measured through the strain full-bridge circuit.

The high-reliability implementation method of the high-reliability piezoelectric directional adjusting mechanism comprises the following specific steps: two piezoelectric stack layers of each piezoelectric driving unit are arranged, and two electrode surfaces are arranged in an aligned mode, so that the failure mode of a mechanism or an associated driving circuit caused by breakdown of a single piezoelectric stack is effectively avoided;

the two piezoelectric stacks of each piezoelectric driving unit are connected in series, the voltage on each piezoelectric stack is one half of the total voltage of the piezoelectric driving unit without the series design during normal work, the working voltage of the piezoelectric stacks is reduced, and the service life of the piezoelectric stacks can be greatly prolonged;

pasting a strain gauge on the surface of the piezoelectric stack, wherein the strain output of the strain gauge strictly corresponds to the driving voltage on the piezoelectric stack; when one piezoelectric stack breaks down, a short circuit appears between the piezoelectric stack electrodes, the surface resistance strain gauge does not have strain output, the piezoelectric driving unit still has one piezoelectric stack to work, the driving voltage of the piezoelectric driving unit is unchanged, the voltage on the piezoelectric stack which still normally works is twice of the driving voltage before the fault, and the strain output is also twice of the driving voltage before the fault. Therefore, when one piezoelectric stack under any shaft fails, the strain bridge can still work and is matched with the drive control circuit to realize high-precision pointing adjustment;

two piezoelectric stacks located in different piezoelectric driving units are broken down and fail under an X axis or a Y axis, a strain gauge on the surface of the failed piezoelectric stack outputs without strain, the driving voltage of the other piezoelectric stack of the piezoelectric driving unit is increased by two times, the output strain of the strain gauge is also increased by two times before failure, the piezoelectric directional adjusting mechanism can still realize deflection work, and the output stroke, the measuring function and the performance are not affected.

Compared with the prior art, the invention has the following advantages:

1) the redundancy design of the device is realized by the way that two piezoelectric stacks with the same specification are mounted on a laminated structure and the driving voltages are connected in series, namely one piezoelectric stack is broken down at any position under a certain shaft, or one piezoelectric stack is broken down for each different piezoelectric driving unit under a certain shaft, the equipment can still work, the function and the performance of the mechanism cannot be influenced, and the reliability of the mechanism is improved;

2) the piezoelectric stacks are capacitive loads, two piezoelectric stacks with the same capacitance value are connected in series and are installed in a splicing mode in the height direction, and a single piezoelectric stack is replaced, so that the driving voltage of the single piezoelectric stack can be reduced, and the service life of the piezoelectric stack can be greatly prolonged;

3) the equivalent capacitance value of the two piezoelectric stacks is halved after the two piezoelectric stacks are connected in series, and the driving current is also halved compared with the original form under the condition that the driving voltage condition is not changed, so that the heating of the piezoelectric stacks can be greatly reduced, and the service life of the piezoelectric stacks is prolonged;

4) the deflection angle is measured in a mode that strain foils are adhered to the surface of the piezoelectric stack to form a strain full bridge, and the power consumption and the heat consumption of the circuit are reduced by increasing the resistance of the bridge circuit while the overall use reliability of the plurality of strain foils is ensured.

Drawings

Fig. 1 is an exploded view of a piezoelectric pointing adjustment mechanism according to the present invention.

Fig. 2 is a schematic diagram of the piezoelectric driving unit.

Fig. 3a is an electrical connection diagram of the first piezoelectric driving unit and the third piezoelectric driving unit.

Fig. 3b is an electrical connection diagram of the second piezoelectric driving unit and the fourth piezoelectric driving unit.

FIG. 4 is a schematic diagram of a specific connection mode of a Y-axis deflection measurement strain bridge.

Detailed Description

The invention is described in further detail below with reference to the following figures and detailed description:

as shown in fig. 1, the high-reliability piezoelectric direction adjusting mechanism of the present invention includes an integrated housing 1 including a flexible ring, the integrated housing 1 including the flexible ring is concentrically mounted on a base 6 through a first positioning pin 5, a second positioning pin 7 and a third positioning pin 10, and is connected and fixed with the base through a first set screw 4, a second set screw 8, a third set screw 9 and a fourth set screw 11, a first piezoelectric driving unit 3, a second piezoelectric driving unit 12, a third piezoelectric driving unit 13 and a fourth piezoelectric driving unit 2 are fixed on the base 6, and are bonded and fixed in an array of 90 ° around the center of a circle of a mounting surface on the base; the integrated shell 1 containing the flexible ring is internally provided with a tapered hole, and the positioning mode corresponds to four piezoelectric driving units arranged on the base one by one; the first piezoelectric driving unit 3, the second piezoelectric driving unit 12, the third piezoelectric driving unit 13 and the fourth piezoelectric driving unit 2 have the same structure. As shown in fig. 2, the first piezoelectric driving unit 3 includes, from top to bottom, a first buffer ball 3.1, a first metal pad 3.2, a first resistance strain gauge 3.3, a second resistance strain gauge 3.4, a first piezoelectric stack 3.5, a third resistance strain gauge 3.6, a fourth resistance strain gauge 3.7, and a second piezoelectric stack 3.8. The internal connection relationship of the first piezoelectric driving unit 3 is as follows: the first buffer ball 3.1 is connected with the integrated machine shell 1 with the flexible ring, the position of the first buffer ball is restrained by a conical groove in the integrated machine shell 1 with the flexible ring, the first buffer ball 3.1 is in contact with the first metal gasket 3.2 through the installation stress of the integrated machine shell with the flexible ring, the first resistance strain gauge 3.3 and the second resistance strain gauge 3.4 are adhered to two smooth surfaces opposite to the first piezoelectric stack 3.5 and are centrally adhered, and the third resistance strain gauge 3.6 and the fourth resistance strain gauge 3.7 are adhered to two smooth surfaces opposite to the second piezoelectric stack 3.8 and are centrally adhered; the first piezoelectric stack 3.5 and the second piezoelectric stack 3.8 are arranged in a laminated manner, and two electrode surfaces are aligned;

the deflection direction of the working output of the first piezoelectric driving unit 3 and the third piezoelectric driving unit 13 is an X axis, and the deflection direction of the second piezoelectric driving unit 12 and the fourth piezoelectric driving unit 2 is a Y axis.

A high-reliability piezoelectric directional adjusting mechanism is electrically connected in the following mode:

a high-reliability piezoelectric directional adjusting mechanism is independently controlled by a two-dimensional deflection driving signal, and the wiring modes of double-shaft driving circuits are the same. As described above, the first piezoelectric driving unit 3 and the third piezoelectric driving unit 13 have the X-axis deflection direction, and the second piezoelectric driving unit 12 and the fourth piezoelectric driving unit 2 have the Y-axis deflection direction. Two driving units under the same deflection axis X or Y are driven differentially, and the piezoelectric stacks arranged on each driving unit in a laminated mode are connected in series.

As shown in fig. 3a, the positive pole of the first piezo stack 3.5 of the first piezo drive unit 3 is connected to a fixed high voltage + HV, for example, a 100V signal, and the negative pole of the first piezo stack 3.5 is connected to the positive pole of the second piezo stack 3.8. The cathode of the second piezo-electric stack 3.8 is connected to the external drive signal Vin _ X, the cathode of the second piezo-electric stack 3.8 is simultaneously connected to the anode of 13.4 of the fifth piezo-electric stack in another piezo-electric drive unit, i.e. the third piezo-electric drive unit 13, under the same deflection axis, the cathode of 13.4 of the fifth piezo-electric stack is connected to the anode of 13.7 of the sixth piezo-electric stack, and the cathode of 13.7 of the sixth piezo-electric stack is connected to a fixed negative signal-HV, e.g. 0V. The external driving signal Vin _ X is controlled to change between-HV and + HV, differential driving of two driving units under X can be achieved, and deflection around the X axis can be achieved.

The electrical connection of the Y-axis down-pressure drive unit is similar to that of the X-axis. As shown in fig. 3b, the positive pole of the third piezo stack 12.5 of the second piezo drive unit 12 is connected to a fixed high voltage + HV signal, for example, a 100V signal, and the negative pole of the third piezo stack 12.5 is connected to the positive pole of the fourth piezo stack 12.8. The cathode of the fourth piezo stack 12.8 is connected to the external drive signal Vin _ Y, the cathode of the fourth piezo stack 12.8 is simultaneously connected to the anode of 2.4 of the seventh piezo stack in the fourth piezo drive unit 2, which is another piezo drive unit under the same deflection axis, the cathode of 2.4 of the seventh piezo stack is connected to the anode of 2.7 of the eighth piezo stack, and the cathode of 2.7 of the eighth piezo stack is connected to a fixed negative signal HV, e.g. 0V. And the external driving signal Vin _ Y is controlled to change between-HV and + HV, so that differential driving of two driving units under Y can be realized, and deflection around the Y axis can be realized.

A high-reliability piezoelectric pointing adjusting mechanism strain sensing electrical connection form is as follows:

as described above, the resistance strain gauge is adhered to the surface of the piezoelectric stack, the X-axis or Y-axis deflection measuring circuit is independent, and eight resistance strain gauges of four piezoelectric stacks under the X-axis or Y-axis form a strain full bridge.

When measuring deflection around the X axis, a first resistance strain gage 3.3, a second resistance strain gage 3.4, a third resistance strain gage 3.6, a fourth resistance strain gage 3.7 on the first piezoelectric driving unit 3 and a ninth resistance strain gage 13.3 on the third piezoelectric driving unit 13, an X-axis deflection measurement strain bridge is formed by a tenth resistance strain gauge 13.4, an eleventh resistance strain gauge 13.6 and a twelfth resistance strain gauge 13.7, the first resistance strain gauge 3.3 is located at the position of a first resistor R1, the second resistance strain gauge 3.4 is located at the position of a sixth resistor R6, the third resistance strain gauge 3.6 is located at the position of a second resistor R2, the fourth resistance strain gauge 3.7 is located at the position of a fifth resistor R5, the ninth resistance strain gauge 13.3 is located at the position of a third resistor R3, the tenth resistance strain gauge 13.4 is located at the position of an eighth resistor R8, the eleventh resistance strain gauge 13.6 is located at the position of a fourth resistor R4, and the twelfth resistance strain gauge 13.7 is located at the position of a seventh resistor R7; the electrical connection positions of the resistance strain gauges on the same bridge arm can be interchanged. In the figure, Eg + and Eg-are the positive and negative poles of the bridge circuit excitation voltage respectively, and V + and V-are the positive and negative poles of the bridge circuit output signal respectively.

When the deflection around the Y axis is measured, a Y axis deflection measuring strain bridge is formed by a fifth resistance strain gauge 12.3, a sixth resistance strain gauge 12.4, a seventh resistance strain gauge 12.6, an eighth resistance strain gauge 12.7 on the second piezoelectric driving unit 12, a thirteenth resistance strain gauge 2.3, a fourteenth resistance strain gauge 2.4, a fifteenth resistance strain gauge 2.6 and a sixteenth resistance strain gauge 2.7 on the fourth piezoelectric driving unit 2. The specific connection is shown in fig. 4, the sixth resistance strain gage 12.3 is located at the position of the first resistance R1, the sixth resistance strain gage 12.4 is located at the position of the sixth resistance R6, the seventh resistance strain gage 12.6 is located at the position of the second resistance R2, and the eighth resistance strain gage 12.7 is located at the position of the fifth resistance R5. The thirteenth resistive strain gage 2.3 is located at the position of the third resistor R3, the fourteenth resistive strain gage 2.4 is located at the position of the eighth resistor R8, the fifteenth resistive strain gage 2.6 is located at the position of the fourth resistor R4, and the sixteenth resistive strain gage 2.7 is located at the position of the seventh resistor R7. The electrical connection positions of the resistance strain gauges on the same bridge arm can be interchanged. In the figure, Eg + and Eg-are the positive and negative poles of the bridge circuit excitation voltage respectively, and V + and V-are the positive and negative poles of the bridge circuit output signal respectively.

The working principle of the high-reliability piezoelectric directional adjusting mechanism is described as follows:

as described above, each piezoelectric driving unit has two piezoelectric stacks connected in series, and is used as one piezoelectric stack, and is connected in a differential manner. The control of the output deflection angle of the shaft can be realized by controlling the driving control signal Vin _ X or Vin _ Y. The voltage anode and voltage cathode access points and the specific numerical value can be matched and determined according to the specification of the selected piezoelectric stack.

As shown above, the deflection angle can be measured by a strain measurement bridge consisting of the resistance strain gauge on the X axis or the Y axis, and the X axis bridge and the Y axis bridge are relatively independent electrically. When the driving control voltage changes, the voltage of the strain full-bridge circuit also changes, and after the relation between the output signal of the strain full-bridge circuit and the deflection angle of the mechanism is calibrated, the deflection angle of an X axis or a Y axis can be measured through the strain full-bridge circuit.

The high reliability realization of the high reliability piezoelectric directional regulating mechanism of the invention is described as follows:

the piezoelectric directional adjusting mechanism mainly shows that the piezoelectric stack breaks down, and once the piezoelectric stack breaks down, the whole device fails in the conventional similar device. According to the invention, two piezoelectric stack layers of each piezoelectric driving unit are arranged and two electrode surfaces are aligned, so that the failure mode of a mechanism or an associated driving circuit caused by breakdown of a single piezoelectric stack can be effectively avoided.

Taking a deflection axis X or Y as an example, the deflection axis adopts a differential driving mode, and compared with a mode that a single piezoelectric stack is used as a driving unit, two piezoelectric stacks of each piezoelectric driving unit are connected in series, and the voltage on each piezoelectric stack is half of the total voltage of the piezoelectric driving unit without the series connection design during normal work. The working voltage of the voltage stack is reduced, and the service life of the voltage stack can be greatly prolonged.

When one piezoelectric stack breaks down, a short circuit appears between the piezoelectric stack electrodes, the piezoelectric stack can still work in the piezoelectric driving unit, and the voltage is raised to be twice of that before the fault, so that the deflection function and performance can still be ensured.

The invention pastes strain gauge strain output on the surface of the piezoelectric stack and strictly corresponds to the driving voltage on the piezoelectric stack. When one piezoelectric stack breaks down, a short circuit appears between the piezoelectric stack electrodes, the surface resistance strain gauge does not have strain output, one piezoelectric stack can still work in the piezoelectric driving unit, the driving voltage of the piezoelectric driving unit is unchanged, the voltage on the piezoelectric stack which still normally works is twice of the driving voltage before the fault, and the strain output is also twice of the driving voltage before the fault. Therefore, when one piezoelectric stack under any shaft fails, the strain bridge can still work and can be matched with a driving control circuit to realize high-precision pointing adjustment.

Similarly, two piezoelectric stacks located in different piezoelectric driving units are broken down and fail under an X axis or a Y axis, a strain gauge on the surface of the failed piezoelectric stack outputs without strain, the driving voltage of the other piezoelectric stack of the piezoelectric driving unit is increased by two times, the output strain of the strain gauge is also increased by two times before the failure, the piezoelectric directional adjusting mechanism can still realize deflection work, and the output stroke and the measuring function and performance are not affected.

In addition, the piezoelectric stack has extremely high service life and high correlation degree of driving voltage, and the service life of the piezoelectric stack can be greatly prolonged by taking the piezoelectric stack into account of connection of series connection and difference connection.