Displacement measuring device and method of piezoelectric bimorph based on load
Through the load assembly composed of fixed pulleys and non-elastic wire ropes, combined with laser displacement sensors, the problem of spring load capacity changes with displacement is solved, and the accuracy and simplified disassembly and assembly of piezoelectric dual chip displacement characteristics are achieved.
Patent Information
- Application Number
- CN202510754399.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-06
- Publication Date
- 2025-08-12
AI Technical Summary
In the prior art, when a spring is used as the load of the piezoelectric dual wafer to be tested, the load force will change with the displacement change of the piezoelectric dual wafer to be tested, resulting in inaccurate displacement characteristics test results.
The load assembly consisting of a fixed pulley, an elastic wire rope and a load body is used to instantly load the load force and keep it constant, and does not change with the displacement change of the piezoelectric dual wafer to be measured. The displacement amount is measured with a laser displacement sensor.
The accuracy of the displacement characteristic test of piezoelectric dual wafers is improved, and the disassembly and assembly operation of the piezoelectric dual wafer to be tested is simplified, avoiding test errors caused by changes in load capacity.
Smart Images
Figure CN120467196A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of this specification relate to the technical field of piezoelectric bimorph testing, and specifically to a displacement measurement device and method for a load-based piezoelectric bimorph. Background Art
[0002] As a typical intelligent material drive element, piezoelectric bimorphs offer advantages such as compact structure, rapid response, high output force, and high displacement resolution. They are widely used in precision positioning, micro-nano manipulation, and other fields. For example, a piezoelectric servo driven by a piezoelectric bimorph is mounted on an aircraft. When the aircraft needs to change its attitude, the piezoelectric bimorph drives the piezoelectric servo to the desired position, thereby completing the attitude change. Compared to traditional electromagnetic actuators, their direct displacement generation through the inverse piezoelectric effect avoids the errors introduced by transmission mechanisms, making them particularly suitable for scenarios requiring high-precision dynamic control.
[0003] The piezoelectric dual-chip needs to be tested for displacement characteristics before use (i.e., first input an excitation signal to the piezoelectric dual-chip, then obtain the displacement of the piezoelectric dual-chip for the excitation signal, and finally determine the displacement characteristics of the piezoelectric dual-chip through the displacement). When performing the displacement characteristic test, it is necessary to set a load on the piezoelectric dual-chip to be tested, and use the load to provide a load force to the piezoelectric dual-chip to be tested. In the prior art, a spring is used as the load of the piezoelectric dual-chip to be tested, but the load force provided by the spring will continue to change with the displacement of the piezoelectric dual-chip to be tested (i.e., the load force applied to the piezoelectric dual-chip to be tested is not fixed), which will lead to inaccurate test results of the piezoelectric dual-chip displacement characteristic test. Summary of the Invention
[0004] In view of the shortcomings of the prior art, the embodiments of this specification propose a displacement measurement device and method based on a load-based piezoelectric bimorph.
[0005] A displacement measurement device for a piezoelectric bimorph based on a load comprises: a load assembly connected to the piezoelectric bimorph to be measured, and a base platform connected to the load assembly; the load assembly comprises: fixed pulley; A fixed pulley mounting frame, the top of which is connected to the fixed pulley, and the bottom of which is connected to the base platform; An inelastic rope is wound around the fixed pulley, and a first end of the inelastic rope is connected to the piezoelectric bimorph to be measured; The load body is connected to the second end of the inelastic rope.
[0006] Preferably, the inelastic cord is connected to the top of the piezoelectric bimorph to be tested using high-strength welding glue.
[0007] Preferably, the load body is a weight with a hook, and the second end of the inelastic rope is provided with a hanging ring detachably connected to the weight with a hook.
[0008] Preferably, the displacement measuring device further comprises: The displacement measuring component is used to detect the displacement of the piezoelectric bimorph to be measured, and the displacement measuring component is connected to the base platform.
[0009] Preferably, the displacement measuring component is a laser displacement sensor.
[0010] Preferably, the displacement measuring component and the base platform are connected via a magnetic base.
[0011] Preferably, the displacement measuring device further comprises: The wafer mounting frame is used to mount the piezoelectric bimorph to be tested, and the wafer mounting frame is connected to the base platform.
[0012] Preferably, the wafer mounting frame comprises: A bottom support block, the bottom of which is connected to the base platform, the top surface of the bottom support block is provided with a wafer support area for placing part of the piezoelectric bimorph to be tested, and the bottom support block is provided with a threaded connection hole at a position other than the wafer support area; The top pressing block has a chip pressing area on its bottom surface for pressing part of the piezoelectric dual chip to be tested, and the top pressing block has a threaded docking hole at a position other than the chip pressing area, and the threaded docking hole and the threaded connection hole are detachably connected by screws.
[0013] Preferably, the wafer mounting frame further comprises an elastic layer provided on the top surface of the bottom support block and the bottom surface of the top press-fitting block.
[0014] A method for measuring displacement of a piezoelectric bimorph based on a load, comprising: S1. Determine the piezoelectric bimorph to be tested and install the piezoelectric bimorph through the wafer mounting frame: Place the first end of the piezoelectric bimorph to be tested on the wafer support area of the bottom support block, and press the wafer press-fitting area of the top press-fitting block onto the first end of the piezoelectric bimorph to be tested, and then connect and fix the threaded connection hole of the top press-fitting block to the threaded connection hole of the bottom support block by screws; S2. Select a load body of appropriate weight and connect the inelastic cord to the piezoelectric bimorph to be tested and the load body: Secure the first end of the inelastic cord to the top surface of the piezoelectric bimorph to be tested using high-strength welding glue. Then, attach the second end of the inelastic cord to the weight with a hook. S3. Measuring the displacement value of the piezoelectric bimorph to be measured by the displacement measuring component: moving the position of the laser displacement sensor so that the laser emission of the laser displacement sensor is aligned with the side of the second end of the piezoelectric bimorph to be measured, obtaining the basic displacement value of the piezoelectric bimorph to be measured by the laser displacement sensor, inputting an excitation signal to the piezoelectric bimorph to be measured and obtaining the excitation displacement value of the piezoelectric bimorph to be measured under the excitation signal by the laser displacement sensor; S4. Determine the displacement of the piezoelectric bimorph to be measured under the excitation signal based on the excitation displacement value and the basic displacement value.
[0015] Beneficial effects In the displacement measurement device and method of the embodiments of this specification, the load force acting on the piezoelectric dual-chip to be tested is generated by a load assembly including a fixed pulley, a fixed pulley mounting frame, an inelastic rope and a load body. The load assembly can instantaneously load the load force on the piezoelectric dual-chip to be tested and ensure that the load force does not change with the output displacement of the piezoelectric dual-chip to be tested, thereby improving the accuracy of the test results of the displacement characteristic test of the piezoelectric dual-chip.
[0016] In addition, the chip mounting rack of this embodiment can make the disassembly and assembly of the piezoelectric bimorph to be tested very simple and convenient, and can ensure that the piezoelectric bimorph to be tested is clamped while avoiding being damaged by clamping.
[0017] Further or more detailed beneficial effects will be described in conjunction with specific examples in the specific implementation manner. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a schematic structural diagram of a displacement measuring device in an embodiment of this specification; Figure 2 It is the displacement value output by the piezoelectric bimorph to be tested based on a certain excitation signal in the embodiments of this specification. DETAILED DESCRIPTION
[0019] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.
[0020] Example 1: like Figure 1 As shown, this embodiment provides a load-based piezoelectric dual-chip displacement measurement device, which includes a load component connected to the piezoelectric dual-chip 1 to be measured, a base platform 4 connected to the load component, a displacement measuring component 5 for detecting the displacement of the piezoelectric dual-chip 1 to be measured and connected to the base platform 4, and a chip mounting frame 3 for mounting the piezoelectric dual-chip 1 to be measured and connected to the base platform 4.
[0021] The piezoelectric bimorph 1 to be tested has three leads, each with an interface. Assume that these three leads are the base lead, lead A, and lead B. After the piezoelectric bimorph 1 to be tested is secured by the wafer mounting frame 3, if the excitation signal generating device is connected to the base lead and lead A, the piezoelectric bimorph 1 to be tested will move downward during the displacement characteristics test. In this case, the excitation signal generating device is connected to the base lead and lead A. If the excitation signal generating device is connected to the base lead and lead B, the piezoelectric bimorph 1 to be tested will move downward during the displacement characteristics test. In this case, the excitation signal generating device is connected to the base lead and lead B.
[0022] After the piezoelectric bimorph 1 to be tested is fixed by the wafer mounting frame 3 , a load needs to be set on the piezoelectric bimorph 1 to be tested.
[0023] In this embodiment, the load assembly includes: a fixed pulley, a fixed pulley mounting frame 7 , an inelastic rope 6 and a load body 8 .
[0024] The top of fixed pulley mounting frame 7 is connected with fixed pulley, and the bottom of fixed pulley mounting frame 7 is connected with base platform 4. Fixed pulley mounting frame 7 is provided with support shaft, and fixed pulley can rotate around support shaft.
[0025] An inelastic cord 6 is wound around the fixed pulley, with its first end connected to the piezoelectric bimorph 1 under test. A rope groove is provided on the outer circumference of the fixed pulley, with the body of the inelastic cord 6 positioned within it. In this embodiment, the inelastic cord 6 is wound only in the upper half of the rope groove, and remains in this position regardless of the rotation of the fixed pulley. Both ends of the inelastic cord 6 hang vertically. The inelastic cord 6 itself does not deform and is used to transmit the external force provided by the load body 8.
[0026] The load body 8 is connected to the second end of the inelastic cord 6. The load body 8 is a weight with a hook, and the second end of the inelastic cord 6 is equipped with a hook ring that is detachably connected to the weight with a hook. This allows for easy connection and removal of the weight with a hook from the inelastic cord 6, making it easy to obtain a load body 8 of the desired weight.
[0027] The external force acting on the piezoelectric bimorph 1 under test is consistent with the gravity acting on the load body 8. When the piezoelectric bimorph 1 under test moves downward, it is subjected to a pulling force from the load body 8 of the same magnitude as gravity. This force is applied instantaneously, unlike the load force applied by a spring load. The load force applied by a spring load varies with the output displacement of the piezoelectric bimorph 1 under test. However, the load assembly of this embodiment can instantaneously apply a load force to the piezoelectric bimorph 1 under test while ensuring that the load force does not vary with the output displacement of the piezoelectric bimorph 1 under test, thereby improving the accuracy of the test results of the piezoelectric bimorph displacement characteristics test.
[0028] Furthermore, the displacement measuring component 5 in this embodiment is a laser displacement sensor.
[0029] The bottom of the laser displacement sensor is connected to the base platform 4. The top of the laser displacement sensor emits laser light toward the bottom surface of the piezoelectric bimorph 1 under test. After the laser strikes the bottom surface of the piezoelectric bimorph 1 under test, it is reflected back to the laser displacement sensor. The laser displacement sensor calculates the distance to the piezoelectric bimorph 1 under test by calculating the time difference between emitting and receiving the laser light.
[0030] Assume that when no excitation signal is applied to the piezoelectric bimorph 1 under test, the laser displacement sensor detects a distance S1 between it and the piezoelectric bimorph 1 under test. After applying a certain excitation signal, the laser displacement sensor detects a distance S2 between it and the piezoelectric bimorph 1 under test. Subtracting S2 from S1 yields the displacement of the piezoelectric bimorph 1 under test in response to the excitation signal.
[0031] Assume that in a certain usage scenario, the displacement of a piezoelectric bimorph 1 under test in response to a certain excitation signal is required to be greater than a displacement threshold L. During the test, if the displacement of the piezoelectric bimorph 1 under test in response to the excitation signal is found to be greater than the displacement threshold L, then the displacement characteristics of the piezoelectric bimorph 1 under test meet the usage requirements of the usage scenario. Otherwise, the displacement characteristics of the piezoelectric bimorph 1 under test do not meet the usage requirements of the usage scenario.
[0032] In this embodiment, the laser displacement sensor is connected to the base platform 4 through a magnetic base. The magnetic base is fixedly connected to the bottom of the laser displacement sensor, and a magnetic surface is provided at the bottom of the magnetic base. A switch is provided on the magnetic base. When the switch is turned on, the magnetic surface has a magnetic attraction force, so that the magnetic base is connected and fixed to the base platform 4; when the switch is turned off, the magnetic surface loses its magnetic attraction force, so that the magnetic base and the base platform 4 can be separated. When the switch is turned off, the laser displacement sensor can move on the base platform 4, and then the installation position of the laser displacement sensor relative to the base platform 4 can be adjusted. After the laser displacement sensor moves to the installation position, the switch is turned on again, so that the laser displacement sensor is connected and fixed to the base platform 4 through the magnetic base.
[0033] When the laser displacement sensor's laser is aligned with the side of the piezoelectric bimorph 1 under test, the piezoelectric bimorph displacement characteristics test results are most accurate. However, due to factors such as the size of the piezoelectric bimorph 1 under test and installation errors, the laser of the previously fixed laser displacement sensor may not be aligned with the side of the next piezoelectric bimorph 1 under test. In this case, the magnetic base can be used to adjust the laser displacement sensor's installation position so that the laser of the laser displacement sensor can be aligned with the side of the piezoelectric bimorph 1 under test, thereby improving the accuracy of the piezoelectric bimorph displacement characteristics test results.
[0034] In addition, the laser displacement sensor has a micron-level accuracy and a ±15mm range. The displacement data collected by the laser displacement sensor can be directly sent to the host computer.
[0035] Furthermore, the wafer mounting frame 3 in this embodiment includes a bottom support block and a top press-fit block.
[0036] The bottom of the bottom support block is connected to the base platform 4. The top surface of the bottom support block is provided with a wafer support area for placing a portion of the piezoelectric bimorph 1 to be tested. The bottom support block also has a threaded connection hole in a position other than the wafer support area. The threaded connection hole is vertically provided on the bottom support block and vertically penetrates the top surface of the bottom support block.
[0037] The bottom surface of the top press-fit block is provided with a wafer press-fit area for pressing a portion of the piezoelectric bimorph 1 to be tested. The top press-fit block is also provided with a threaded docking hole located outside the wafer press-fit area. The threaded docking hole and the threaded connection hole are removably connected via screws. The threaded docking hole is vertically provided on the top support block and extends vertically through the entire top support block. The top support block can be provided with four threaded docking holes, and the bottom support block can be provided with four threaded connection holes that correspond one-to-one with the threaded docking holes.
[0038] When replacing the piezoelectric dual chip 1 to be tested, the screw can be first rotated to separate from the threaded connection hole of the bottom support block. At this time, the screw is still in the threaded docking hole of the top press-fitting block (there is no need to detach the screw from the top press-fitting block); then the top press-fitting block is removed from the bottom support block and the piezoelectric dual chip that has been tested is removed; then one end of the new piezoelectric dual chip 1 to be tested is placed on the chip support area of the bottom support block and the top press-fitting block is pressed on the top of the end of the piezoelectric dual chip 1 to be tested; finally, the screw on the top press-fitting block is rotated so that the screw enters the threaded connection hole of the bottom support block to connect and fix the top press-fitting block to the bottom support block, and finally the installation of the piezoelectric dual chip 1 to be tested is completed.
[0039] The wafer mounting frame 3 also includes an elastic layer 2 disposed on the top surface of the bottom support block and the bottom surface of the top press-fit block. The elastic layer 2 can be located solely on the wafer support area of the bottom support block and the wafer press-fit area of the top press-fit block, or it can cover the entire top surface of the bottom support block and the entire bottom surface of the top press-fit block (this only requires that the elastic layer 2 include through-holes that mate with the threaded connection holes or threaded mating holes).
[0040] The elastic layer 2 can be made of TPU material with a thickness of 0.5 mm and a hardness of 91. The piezoelectric bimorph 1 to be tested typically has solder joints (with a maximum height of 0.4 mm). The provision of the elastic layer 2 ensures that the piezoelectric bimorph 1 to be tested is clamped while preventing damage. The elastic layer 2 protects the solder joints on the piezoelectric bimorph 1 to be tested, preventing them from directly contacting the top press block or bottom support block.
[0041] The chip mounting rack 3 of this embodiment can make the disassembly and assembly operations of the piezoelectric bimorph 1 to be tested very simple and convenient, and can ensure that the piezoelectric bimorph 1 to be tested is clamped while avoiding being damaged by clamping.
[0042] The specific measurement process of the piezoelectric bimorph 1 to be measured is as follows: First, the piezoelectric bimorph 1 to be tested is connected and fixed to the wafer mounting frame 3 , and then the piezoelectric bimorph 1 to be tested is connected to the excitation signal generating device.
[0043] Then, the first end of the elastic rope 6 is fixed to the piezoelectric dual chip 1 to be tested using high-strength welding glue, and then a load body 8 of reasonable weight (i.e., a weight with a hook, the weight of the weight with a hook can be 50 grams, to ensure that the force generated by the weight with a hook is within the range that the piezoelectric dual chip 1 to be tested can withstand) is selected and connected to the second end of the elastic rope 6.
[0044] Then adjust the position of the displacement measuring component 5 (i.e., the laser displacement sensor) so that the emitted laser of the laser displacement sensor is just aimed at the side of the piezoelectric dual-chip 1 to be measured, and obtain the displacement value a of the piezoelectric dual-chip 1 to be measured at the current moment through the laser displacement sensor (the displacement value a is used as the basic displacement value).
[0045] Next, select an appropriate excitation signal. This can be a sine wave, triangle wave, or any other waveform. The maximum excitation signal frequency should not exceed tens of kilovolts per second. The upper limit of the excitation signal frequency is determined by the piezoelectric bimorph model and the performance of the signal acquisition system. For example, the excitation signal could be a constant-amplitude triangle wave with a frequency of 20V / s, a minimum amplitude of 0V, and a maximum amplitude of 200V.
[0046] Then, the excitation signal generating device is used to input the selected excitation signal to the piezoelectric bimorph 1 to be tested, and the displacement value b of the piezoelectric bimorph 1 to be tested under the action of the excitation signal is obtained through the laser displacement sensor (the displacement value b is used as the excitation displacement value. Since the amplitude of the excitation signal is constantly changing, the displacement value b is also constantly changing). The output displacement value b of the piezoelectric bimorph 1 to be tested can be as follows: Figure 2 The graphic shown.
[0047] Finally, the displacement of the piezoelectric bimorph 1 to be tested under the action of the excitation signal is calculated based on the displacement value a and the displacement value b, and it is determined based on the displacement value whether the displacement characteristics of the piezoelectric bimorph 1 to be tested meet the use requirements.
[0048] In addition, the waveform, amplitude or frequency of the excitation signal can be adjusted while keeping the weight of the load body 8 unchanged, thereby being able to test the displacement output characteristics of the piezoelectric dual chip 1 to be tested with excitation signals of different waveforms, amplitudes and frequencies under fixed load conditions.
[0049] The weight of the load body 8 can also be adjusted while keeping the excitation signal unchanged, thereby being able to test the displacement output characteristics of the piezoelectric bimorph 1 under different load conditions with the same excitation signal input.
[0050] When the displacement output characteristic test of a certain piezoelectric bimorph 1 to be tested is completed, it is only necessary to replace the next piezoelectric bimorph 1 to be tested to perform the displacement output characteristic test.
[0051] Example 2: A method for measuring displacement of a piezoelectric bimorph based on a load, comprising: S1. Determine the piezoelectric bimorph 1 to be tested and install it on the wafer mounting frame 3: Place the first end of the piezoelectric bimorph 1 to be tested on the wafer support area of the bottom support block, and press the wafer press-fitting area of the top press-fitting block onto the first end of the piezoelectric bimorph 1 to be tested, and then connect and fix the threaded docking hole of the top press-fitting block to the threaded connection hole of the bottom support block with the screw. S2. Select a load body 8 of appropriate weight and connect the inelastic cord 6 to the piezoelectric bimorph 1 to be tested and the load body 8: Secure the first end of the inelastic cord 6 to the top surface of the piezoelectric bimorph 1 to be tested using high-strength welding glue. Then, attach the second end of the inelastic cord 6 to the weight with a hook. S3. Measure the displacement of the piezoelectric bimorph 1 to be tested using the displacement measuring component 5: Move the laser displacement sensor so that the laser emitted by the laser displacement sensor is aligned with the side of the second end of the piezoelectric bimorph 1 to be tested, obtain the basic displacement value of the piezoelectric bimorph 1 to be tested using the laser displacement sensor, input an excitation signal to the piezoelectric bimorph 1 to be tested, and obtain the excitation displacement value of the piezoelectric bimorph 1 to be tested under the excitation signal using the laser displacement sensor; S4. Determine the displacement of the piezoelectric bimorph 1 to be tested under the excitation signal based on the excitation displacement value and the basic displacement value.
[0052] The displacement measurement method in this embodiment adopts the displacement measurement device in Example 1.
[0053] The excitation signal in this embodiment is generated by an excitation signal generating device, and the piezoelectric bimorph 1 to be tested is connected to the excitation signal generating device via leads, so that the excitation signal generating device can input the generated excitation signal to the piezoelectric bimorph 1 to be tested. The excitation signal in this embodiment can be a sine wave, a triangle wave, or any other waveform.
[0054] For the same piezoelectric bimorph 1 under test, the waveform, amplitude, or frequency of the excitation signal can be adjusted while maintaining the weight of the load body 8 constant, thereby enabling testing of the displacement output characteristics of the piezoelectric bimorph 1 under fixed load conditions with excitation signals of different waveforms, amplitudes, and frequencies. Furthermore, the weight of the load body 8 can be adjusted while maintaining the excitation signal constant, thereby enabling testing of the displacement output characteristics of the piezoelectric bimorph 1 under different load conditions with the same excitation signal input.
[0055] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the concept and scope of the present invention. Any modifications and improvements made to the technical solution of the present invention by a person of ordinary skill in the art without departing from the design concept of the present invention shall fall within the scope of protection of the present invention. The technical content for which protection is sought in the present invention is fully set forth in the claims.
Claims
1. A displacement measurement device based on a load-bearing piezoelectric bimorph, characterized in that: include: A load component connected to the piezoelectric bimorph (1) to be tested, and a base platform (4) connected to the load component; the load component comprises: fixed pulley; A fixed pulley mounting frame (7), the top of which is connected to the fixed pulley, and the bottom of the fixed pulley mounting frame (7) is connected to the base platform (4); An inelastic cord (6) is wound around the fixed pulley, and a first end of the inelastic cord (6) is connected to the piezoelectric bimorph (1) to be tested; The load body (8) is connected to the second rope end of the inelastic rope (6).
2. The displacement measuring device according to claim 1, characterized in that The inelastic cord (6) is connected to the top of the piezoelectric bimorph (1) to be tested using high-strength welding glue.
3. The displacement measuring device according to claim 1, characterized in that The load body (8) is a weight with a hook, and the second rope end of the inelastic rope (6) is provided with a hanging ring detachably connected to the weight with a hook.
4. The displacement measuring device according to claim 1, characterized in that The displacement measuring device further comprises: The displacement measuring component (5) is used to detect the displacement of the piezoelectric bimorph (1) to be measured, and the displacement measuring component (5) is connected to the base platform (4).
5. The displacement measuring device according to claim 4, characterized in that: The displacement measuring component (5) is a laser displacement sensor.
6. The displacement measuring device according to claim 4, characterized in that: The displacement measuring component (5) and the base platform (4) are connected via a magnetic base.
7. The displacement measuring device according to claim 1, characterized in that The displacement measuring device further comprises: A chip mounting frame (3) is used to mount the piezoelectric dual chip (1) to be tested, and the chip mounting frame (3) is connected to the base platform (4).
8. The displacement measuring device according to claim 7, characterized in that: The wafer mounting frame (3) comprises: A bottom support block, the bottom of which is connected to the base platform (4), the top surface of the bottom support block is provided with a chip support area for placing part of the piezoelectric dual chip (1) to be tested, and the bottom support block is provided with a threaded connection hole at a position other than the chip support area; The top pressing block has a bottom surface provided with a chip pressing area for pressing a portion of the piezoelectric dual chip (1) to be tested, and the top pressing block has a threaded docking hole at a position other than the chip pressing area, and the threaded docking hole is detachably connected to the threaded connection hole by a screw.
9. The displacement measuring device according to claim 8, characterized in that: The wafer mounting frame (3) further comprises an elastic layer (2) arranged on the top surface of the bottom support block and the bottom surface of the top pressing block.
10. A method for measuring displacement of a piezoelectric bimorph based on a load, characterized in that: include: S1. Determine the piezoelectric dual chip (1) to be tested and install the piezoelectric dual chip (1) to be tested through the chip mounting frame (3): place the first end of the piezoelectric dual chip (1) to be tested in the chip supporting area of the bottom support block, and press the chip pressing area of the top pressing block onto the first end of the piezoelectric dual chip (1) to be tested, and then connect and fix the threaded docking hole of the top pressing block with the threaded connection hole of the bottom support block by screws; S2. Select a load body (8) of appropriate weight and connect the inelastic cord (6) to the piezoelectric dual chip to be tested (1) and the load body (8): use high-strength welding glue to connect and fix the first end of the inelastic cord (6) to the top surface of the piezoelectric dual chip to be tested (1), and then hang the second end of the inelastic cord (6) to the weight with a hook; S3. Measuring the displacement value of the piezoelectric dual-chip (1) to be measured by the displacement measuring component (5): moving the position of the laser displacement sensor so that the emitted laser of the laser displacement sensor is aligned with the side of the second end of the piezoelectric dual-chip (1) to be measured, obtaining the basic displacement value of the piezoelectric dual-chip (1) to be measured by the laser displacement sensor, inputting an excitation signal to the piezoelectric dual-chip (1) to be measured, and obtaining the excitation displacement value of the piezoelectric dual-chip (1) to be measured under the excitation signal by the laser displacement sensor; S4. Determine the displacement of the piezoelectric bimorph (1) to be tested under the excitation signal based on the excitation displacement value and the basic displacement value.