Calibration method and system for knee assembly of leg-shaped impactor

Abstract

The invention discloses a leg-shaped impactor knee assembly calibration method and system, and the method comprises the steps: a calibration displacement sensor and a calibration force sensor are fixedly arranged on a movable cross beam of a material testing machine, the calibration displacement sensor is parallel to the moving direction of the movable cross beam, and the calibration force sensor is parallel to the loading force direction; the knee assembly is fixedly arranged on the material testing machine, the built-in displacement sensor comprises a plurality of displacement sensors, and the plurality of displacement sensors of the built-in displacement sensor are respectively connected with the plurality of displacement measurement channels of the built-in data collector; respectively connecting a calibration displacement sensor and a calibration force sensor with a reserved measurement channel of a built-in data collector; applying a preset loading force through the material testing machine, and simultaneously obtaining measurement channel data of a built-in data collector; fitting a displacement measurement curve of measurement channel data corresponding to the displacement measurement channel along with bending moment change, and evaluating the displacement measurement curve of the built-in displacement sensor according to a preset calibration interval.

Description

Technical Field

[0001] The present invention relates to the technical field of calibration of aPLI leg-type impactor knee assembly, and in particular to a calibration method of a leg-type impactor knee assembly. Background Art

[0002] Pedestrian protection is an important test item in the vehicle safety evaluation procedure, which aims to examine the active and passive protection capabilities of vehicles for pedestrians. The aPLI leg-type impactor is a key test equipment for pedestrian protection tests, which simulates the structural characteristics of human legs well. In the test, the leg-type impactor directly collides with the vehicle to simulate the damage to the human leg, and the damage is quantitatively measured through a variety of sensors built into the impactor. In order to ensure that the leg-type impactor continues to maintain stable performance and accurate measurements in severe collision conditions, the C-NCAP procedure requires regular calibration of the leg-type impactor, and knee assembly calibration is one of the calibration items.

[0003] The knee assembly of the aPLI leg impactor has three built-in displacement sensors. The calibration of the knee assembly is to examine whether the output curve of the displacement sensor is within the allowable range when the knee is loaded with a standard external force. Although the leg impactor also has a built-in data collector, the existing calibration methods require the use of an additional data collector because it is difficult to achieve signal synchronization across devices. This type of calibration using external data acquisition has two problems. First, the calibration experiment requires more equipment and higher hardware costs. Second, replacing the built-in data acquisition with an external data acquisition changes the calibration object, and the calibration results cannot accurately evaluate the performance of the leg impactor itself. Summary of the invention

[0004] In order to solve at least one aspect of the above problems, the present invention provides a calibration method for a knee assembly of a leg-type impactor, comprising: fixing a calibration displacement sensor and a calibration force sensor on a movable crossbeam of a material testing machine, wherein the movable crossbeam is used to provide a loading force, the calibration displacement sensor is parallel to the moving direction of the movable crossbeam, and the calibration force sensor is parallel to the loading force direction; fixing a knee assembly on the material testing machine, wherein the knee assembly comprises a built-in displacement sensor and a built-in data acquisition device, wherein the built-in displacement sensor comprises a plurality of displacement sensors, and the built-in data acquisition device comprises a plurality of displacement measurement channels and a plurality of pre-set A measurement channel is reserved, and the multiple displacement sensors of the built-in displacement sensor are respectively connected to the multiple displacement measurement channels of the built-in data acquisition device in a one-to-one correspondence; the calibration displacement sensor and the calibration force sensor are respectively connected to the reserved measurement channels of the built-in data acquisition device in a one-to-one correspondence; a preset loading force is applied by a material testing machine, and the measurement channel data of the built-in data acquisition device is obtained at the same time; the measurement channel data corresponding to the calibration force sensor is converted into bending moment, a displacement measurement curve of the measurement channel data corresponding to the displacement measurement channel changing with the bending moment is fitted, and the displacement measurement curve of the built-in displacement sensor is evaluated according to a preset calibration interval.

[0005] Preferably, before the step of fixing the knee assembly on the material testing machine, the step also includes: disassembling the built-in displacement sensor and the built-in data acquisition device of the knee assembly, and connecting the built-in displacement sensor to the displacement measurement channel of the built-in data acquisition device respectively; applying a standard displacement to the built-in displacement sensor, and simultaneously obtaining digital displacement data corresponding to the standard displacement through the built-in data acquisition device; determining the sensitivity coefficient of the displacement measurement channel according to the standard displacement and the digital displacement data, and configuring the measurement channel of the built-in data acquisition device according to the sensitivity coefficient.

[0006] Preferably, the step of determining the sensitivity coefficient of the measurement channel according to the standard displacement and the digital displacement data further comprises: using the least squares method to linearly fit the curve of the standard displacement and the digital displacement data, and determining the sensitivity coefficient of the measurement channel according to the slope of the curve.

[0007] Preferably, the step of applying a preset loading force by means of a material testing machine comprises: the preset loading force adopts a dynamic loading of 0 to 400 Nm, and a loading speed of 10 to 100 mm / min.

[0008] Preferably, the built-in displacement sensor includes a first displacement sensor, a second displacement sensor and a third displacement sensor.

[0009] On the other hand, the present invention provides a leg-type impactor knee assembly calibration system, comprising: a knee assembly, the knee assembly comprising a built-in data acquisition device, a built-in displacement sensor and an assembly mechanism, the built-in data acquisition device comprising a plurality of displacement measurement channels and a plurality of reserved measurement channels, the built-in displacement sensor comprising a plurality of displacement sensors, the plurality of displacement sensors of the built-in displacement sensor being respectively connected to the plurality of displacement measurement channels of the built-in data acquisition device in a one-to-one correspondence, the built-in data acquisition device and the built-in displacement sensor being fixedly arranged in the assembly mechanism; a material testing machine, the material testing machine comprising a bracket, a base, a movable crossbeam and a displacement measurement point , the base is fixedly arranged at the bottom of the bracket, the movable crossbeam is movably connected to the bracket, the displacement measurement point is fixedly arranged on the bracket, the material testing machine also includes a calibration displacement sensor and a calibration force sensor, the calibration displacement sensor is parallel to the moving direction of the movable crossbeam, the calibration force sensor is parallel to the loading force direction, the calibration displacement sensor and the calibration force sensor are respectively connected to the reserved measurement channels of the built-in data acquisition device in a one-to-one correspondence, the calibration force sensor is used to measure the loading force, and the calibration displacement sensor is used to measure the displacement of the movable beam relative to the displacement measurement point. .

[0010] The calibration method and system of the knee assembly of the leg-type impactor of the present invention have the following beneficial effects: the entire calibration process does not require an additional data collector; the built-in sensor and built-in data collector of the knee assembly of the leg-type impactor are used to ensure the integrity of the measurement channel of the calibration object, and the calibration result can directly evaluate the performance of the leg-type impactor itself. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to better understand the above and other purposes, features, advantages and functions of the present invention, reference may be made to the embodiments shown in the accompanying drawings. The same reference numerals in the accompanying drawings refer to the same components. It should be understood by those skilled in the art that the accompanying drawings are intended to schematically illustrate the preferred embodiments of the present invention and have no limiting effect on the scope of the present invention, and the components in the drawings are not drawn to scale.

[0012] Figure 1 A structural block diagram of a calibration system for a leg-type impactor knee assembly according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0013] The following is a description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, including various details of the embodiments of the present disclosure to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present disclosure. Similarly, for the sake of clarity and conciseness, descriptions of well-known functions and structures are omitted in the following description.

[0014] As used herein, the term "including" and its variations mean open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "based at least in part on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0015] In order to at least partially solve the above problems and one or more of other potential problems, an embodiment of the present disclosure proposes a calibration method for a knee assembly of a leg-type impactor, comprising: step S1, fixing a calibration displacement sensor and a calibration force sensor on a movable crossbeam of a material testing machine, the movable crossbeam is used to provide a loading force, the calibration displacement sensor is parallel to the moving direction of the movable crossbeam, and the calibration force sensor is parallel to the loading force direction; step S2, fixing the knee assembly on the material testing machine, the knee assembly includes a built-in displacement sensor and a built-in data acquisition device, the built-in displacement sensor includes a plurality of displacement sensors, and the built-in data acquisition device includes a plurality of displacement sensors. The method comprises the following steps: a first step, a second step, a second step, a third step, a fourth step, a fifth ...

[0016] Specifically, in step S1, the material testing machine includes a bracket, a base, a movable beam and a displacement measurement point, the base is fixedly connected to the bracket, the base is arranged at the bottom of the bracket, the movable beam is arranged above the base, the movable beam is movably connected to the bracket, the displacement measurement point is arranged above the movable beam, and the displacement measurement point is fixedly arranged on the bracket. The material testing machine also includes a calibration displacement sensor and a calibration force sensor, the calibration displacement sensor is parallel to the moving direction of the movable beam, the calibration force sensor is parallel to the loading force direction, the calibration displacement sensor and the calibration force sensor are respectively connected to the reserved measurement channels of the built-in data acquisition device in a one-to-one correspondence, the calibration force sensor is used to measure the loading force, and the calibration displacement sensor is used to measure the displacement of the movable relative displacement measurement point.

[0017] In step S2, the knee assembly adopts the knee assembly of the aPLI leg-type impactor of the prior art. It can be understood by those skilled in the art that the aPLI leg-type impactor is a detachable structure, and the built-in displacement sensor, built-in data acquisition device and assembly mechanism constituting the knee of the aPLI leg-type impactor are used as the knee assembly. The built-in data acquisition device is used to collect the measurement channels of the various built-in sensors of the aPLI leg-type impactor, including the displacement measurement channel corresponding to the displacement sensor of the knee assembly. During the calibration process of the knee assembly, other measurement channels other than the displacement measurement channel of the built-in data acquisition device are left vacant and used as reserved measurement channels.

[0018] In step S3, the knee assembly is connected and fixed on the bracket of the material testing machine, and the calibration force sensor and the calibration displacement sensor are respectively connected to the reserved measurement channels of the built-in data acquisition device, so as to establish the calibration force measurement channel and the calibration displacement measurement channel.

[0019] In step S4, a preset loading force is applied by a material testing machine to obtain measurement channel data corresponding to the preset loading force. The measurement channel data includes displacement measurement channel data corresponding to the built-in displacement sensor, calibration force measurement channel data corresponding to the calibration force sensor, and calibration displacement measurement channel data corresponding to the calibration displacement sensor.

[0020] In step S5, the calibration force measurement channel data is used as an independent variable, and the displacement measurement channel data is used as a dependent variable to produce a displacement measurement curve of the built-in displacement sensor, and the calibration displacement measurement channel data corresponding to the calibration displacement sensor is used as a reference for multiple displacement measurement channel data of the same loading force. The preset calibration interval includes multiple displacement calibration intervals, and the multiple displacement calibration intervals correspond to the multiple displacement measurement curves one by one, respectively, and are used to calibrate and evaluate the multiple displacement sensors of the built-in displacement sensor.

[0021] The object of knee assembly calibration is the knee assembly as a whole, and its measurement channel (measurement chain) is composed of a built-in displacement sensor and a built-in data acquisition device. If a calibration scheme using a built-in displacement sensor and an external data acquisition device is used, the original measurement channel is changed, and the calibration object is partially replaced, thereby affecting the calibration result. The calibration method for knee assembly of leg impactor disclosed in the present invention uses the calibration process of the built-in data acquisition device to avoid measurement errors caused by changes in the calibration object.

[0022] In some embodiments, before the step of fixing the knee assembly on the material testing machine, the step also includes: disassembling the built-in displacement sensor and the built-in data acquisition device of the knee assembly, and connecting the built-in displacement sensor to the displacement measurement channel of the built-in data acquisition device respectively; applying a standard displacement to the built-in displacement sensor, and simultaneously obtaining digital displacement data corresponding to the standard displacement through the built-in data acquisition device; determining the sensitivity coefficient of the displacement measurement channel according to the standard displacement and the digital displacement data, and configuring the measurement channel of the built-in data acquisition device according to the sensitivity coefficient.

[0023] Specifically, after step S1 and before step S2, a calibration step of the displacement sensor is also included, and the calibration step of the displacement sensor includes: step T1, disassembling the built-in displacement sensor and the built-in data acquisition device of the knee assembly. It can be understood by those skilled in the art that the aPLI leg-shaped impactor is an assembled combined structure, so it is necessary to disassemble the knee assembly (including the built-in data acquisition device, the built-in displacement sensor, etc.) in the leg-shaped impactor. The disassembled built-in displacement sensor and the displacement measurement channel of the built-in data acquisition device are connected one by one. When the built-in displacement sensor includes a plurality of displacement sensors, each of the plurality of displacement sensors is respectively connected to a displacement measurement channel of a built-in data acquisition device. Step T2, a series of standard displacement inputs (unit mm) within its range are applied to the built-in displacement sensor, and the digital acquisition displacement data output (unit LSB) of the displacement measurement channel is recorded at the same time. When the built-in displacement sensor includes a plurality of displacement sensors, a sensitivity calibration data group is established for each displacement sensor respectively, and the sensitivity calibration data group includes the standard displacement input and the digital acquisition displacement data of the corresponding displacement sensor, and the sensitivity coefficient of the displacement measurement channel of the built-in displacement sensor is determined respectively according to the sensitivity calibration data group. Step T3, configuring the sensitivity coefficient of the displacement measurement channel obtained in step T2 into the built-in data acquisition device.

[0024] In another embodiment, step S0 is included before step S1, and step S0 is used to calibrate the displacement sensor of the knee assembly. Step S0 analyzes the data of the displacement sensor of the knee assembly to determine the sensitivity coefficient of the displacement sensor. Step S0 includes the aforementioned steps T1 to T3.

[0025] In some embodiments, the step of determining the sensitivity coefficient of the measurement channel according to the standard displacement and the digital displacement data further includes: using the least squares method to linearly fit the curve of the standard displacement and the digital displacement data, and determining the sensitivity coefficient of the measurement channel according to the slope of the curve.

[0026] Specifically, a sensitivity calibration data set is established for each displacement sensor. The sensitivity calibration data set includes a standard displacement input and digital displacement data of the corresponding displacement sensor. The standard displacement input and the digital displacement data are linearly fitted using the least squares method to obtain a straight line in the rectangular coordinate system. The slope of the straight line is the sensitivity coefficient of the displacement measurement channel corresponding to the displacement sensor.

[0027] In some embodiments, the step of applying a preset loading force through a movable crossbeam includes: the preset loading force adopts a dynamic loading of 0 to 400 Nm (Newton meter), and the loading speed is 10 to 100 mm / min.

[0028] In some embodiments, the built-in displacement sensor includes a first displacement sensor, a second displacement sensor, and a third displacement sensor.

[0029] Specifically, the first displacement sensor, the second displacement sensor and the third displacement sensor of the built-in displacement sensor are used to measure the three knee displacement sensor signal curves of ACL, MCL and PCL respectively. In other embodiments, other sensors may also be included, such as angle sensors.

[0030] In some embodiments, the preset calibration interval of the first displacement sensor is:

[0031]

[0032] Wherein, M is the bending moment of the force measurement channel, L1 is the measurement channel data of the first displacement sensor, and the calibration is passed when the displacement measurement curve of the first displacement sensor is within the calibration interval.

[0033] Specifically, a calibration coordinate system is established, with the bending moment of the loading force as the horizontal coordinate M and the displacement as the vertical coordinate L. A displacement measurement curve of the measurement channel data of the first displacement sensor as the loading force changes is drawn in the calibration coordinate system. And the displacement measurement curve of the first displacement sensor is evaluated according to the preset calibration interval corresponding to the first displacement sensor. The curve of the upper limit of the preset calibration interval corresponding to the first displacement sensor in the calibration coordinate system is

[0034]

[0035] The curve of the lower limit of the preset calibration interval corresponding to the first displacement sensor in the calibration coordinate system is

[0036]

[0037] When the displacement measurement curve corresponding to the first displacement sensor is between the upper limit and the lower limit of the preset calibration interval, the calibration of the first displacement sensor passes.

[0038] In some embodiments, the preset calibration interval of the second displacement sensor is:

[0039]

[0040] Wherein, M is the bending moment of the force measurement channel, L2 is the measurement channel data of the second displacement sensor, and the calibration is passed when the displacement measurement curve of the second displacement sensor is within the calibration interval.

[0041] Specifically, the curve of the upper limit of the preset calibration interval corresponding to the second displacement sensor in the calibration coordinate system is:

[0042]

[0043] The curve of the lower limit of the preset calibration interval corresponding to the second displacement sensor in the calibration coordinate system is

[0044]

[0045] When the displacement measurement curve corresponding to the second displacement sensor is between the upper limit and the lower limit of the preset calibration interval, the calibration of the second displacement sensor passes.

[0046] In some embodiments, the preset calibration interval of the third displacement sensor is:

[0047]

[0048] Wherein, M is the bending moment of the force measurement channel, L3 is the measurement channel data of the third displacement sensor, and the calibration is passed when the displacement measurement curve of the third displacement sensor is within the calibration interval.

[0049] Specifically, the curve of the upper limit of the preset calibration interval corresponding to the third displacement sensor in the calibration coordinate system is:

[0050]

[0051] The curve of the lower limit of the preset calibration interval corresponding to the third displacement sensor in the calibration coordinate system is

[0052]

[0053] When the displacement measurement curve corresponding to the third displacement sensor is between the upper limit and the lower limit of the preset calibration interval, the calibration of the third displacement sensor passes.

[0054] On the other hand, a leg-type impactor knee assembly calibration system is provided, including: a knee assembly and a material testing machine, the knee assembly including a built-in data acquisition device, a built-in displacement sensor and an assembly mechanism, the built-in data acquisition device including multiple displacement measurement channels and multiple reserved measurement channels, the built-in displacement sensor including multiple displacement sensors, the multiple displacement sensors of the built-in displacement sensor are respectively connected one-to-one with the multiple displacement measurement channels of the built-in data acquisition device, and the built-in data acquisition device and the built-in displacement sensor are fixedly arranged in the assembly mechanism; the material testing machine includes a bracket, a base, a movable crossbeam and a displacement measurement point, the base is fixedly arranged at the bottom of the bracket, the movable crossbeam is movably connected to the bracket, the displacement measurement point is fixedly arranged on the bracket, the material testing machine also includes a calibration displacement sensor and a calibration force sensor, the calibration displacement sensor is parallel to the moving direction of the movable crossbeam, the calibration force sensor is parallel to the loading force direction, the calibration displacement sensor and the calibration force sensor are respectively connected one-to-one with the reserved measurement channels of the built-in data acquisition device, the calibration force sensor is used to measure the loading force, and the calibration displacement sensor is used to measure the displacement of the movable relative displacement measurement point.

[0055] Specifically, the knee assembly adopts the knee assembly of the aPLI leg-type impactor of the prior art, including a built-in data acquisition device, a built-in displacement sensor and an assembly mechanism. The built-in displacement sensor includes a first displacement sensor, a second displacement sensor and a third displacement sensor, which are respectively used to measure the three knee displacement sensor signal curves of ACL, MCL and PCL. The built-in data acquisition device includes at least three displacement measurement channels and at least one reserved displacement measurement channel and at least one reserved force measurement channel. The base of the material testing machine includes a fixed setting, a bracket is fixedly set on the base, a movable crossbeam is set above the base, and a displacement measurement point is set above the movable crossbeam. The calibration force sensor is connected to the reserved force measurement channel of the built-in data acquisition device, and the calibration displacement sensor is connected to the reserved displacement measurement channel of the built-in data acquisition device.

[0056] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the present invention.

Claims

1. A method for calibrating a knee assembly of a leg-type impactor, characterized in that: include: A calibration displacement sensor and a calibration force sensor are fixedly arranged on a movable crossbeam of the material testing machine, wherein the movable crossbeam is used to provide a loading force, the calibration displacement sensor is parallel to a moving direction of the movable crossbeam, and the calibration force sensor is parallel to a loading force direction; The knee assembly is fixedly arranged on the material testing machine, wherein the knee assembly includes a built-in displacement sensor and a built-in data acquisition device, wherein the built-in displacement sensor includes a plurality of displacement sensors, and the built-in data acquisition device includes a plurality of displacement measurement channels and a plurality of reserved measurement channels, and the plurality of displacement sensors of the built-in displacement sensor are respectively connected to the plurality of displacement measurement channels of the built-in data acquisition device in a one-to-one correspondence; Connecting the calibration displacement sensor and the calibration force sensor to the reserved measurement channels of the built-in data acquisition device respectively in a one-to-one correspondence; Applying a preset loading force through a material testing machine and acquiring measurement channel data of the built-in data acquisition device at the same time; The measurement channel data corresponding to the calibration force sensor is converted into bending moment, a displacement measurement curve of the measurement channel data corresponding to the displacement measurement channel changing with the bending moment is fitted, and the displacement measurement curve of the built-in displacement sensor is evaluated according to a preset calibration interval.

2. The method according to claim 1, characterized in that The step of fixing the knee assembly on the material testing machine also includes: Disassemble the built-in displacement sensor and the built-in data acquisition device of the knee assembly, and connect the built-in displacement sensor to the displacement measurement channel of the built-in data acquisition device respectively; Applying a standard displacement to the built-in displacement sensor, and acquiring digital displacement data corresponding to the standard displacement through the built-in data acquisition device; The sensitivity coefficient of the displacement measurement channel is determined according to the standard displacement and the digital acquisition displacement data, and the measurement channel of the built-in digital acquisition device is configured according to the sensitivity coefficient.

3. The method according to claim 2, characterized in that The step of determining the sensitivity coefficient of the measurement channel according to the standard displacement and the digital displacement data also includes: using the least squares method to linearly fit the curve of the standard displacement and the digital displacement data, and determining the sensitivity coefficient of the measurement channel according to the slope of the curve.

4. The method according to claim 3, characterized in that: The step of applying a preset loading force through a material testing machine includes: the preset loading force adopts a dynamic loading of 0 to 400 Nm, and the loading speed is 10 to 100 mm / min.

5. The method according to claim 4, characterized in that The built-in displacement sensor includes a first displacement sensor, a second displacement sensor and a third displacement sensor.

6. The method according to claim 5, characterized in that The preset calibration interval of the first displacement sensor is: Wherein, M is the bending moment of the force measurement channel, L1 is the measurement channel data of the first displacement sensor, and the calibration is passed when the displacement measurement curve of the first displacement sensor is within the calibration interval.

7. The method according to claim 6, characterized in that The preset calibration interval of the second displacement sensor is: Wherein, M is the bending moment of the force measurement channel, L2 is the measurement channel data of the second displacement sensor, and the calibration is passed when the displacement measurement curve of the second displacement sensor is within the calibration interval.

8. The method according to claim 7, characterized in that The preset calibration interval of the third displacement sensor is: Wherein, M is the bending moment of the force measurement channel, L3 is the measurement channel data of the third displacement sensor, and the calibration is passed when the displacement measurement curve of the third displacement sensor is within the calibration interval.

9. A leg-type impactor knee assembly calibration system, characterized in that: include: A knee assembly, the knee assembly comprising a built-in data collector, a built-in displacement sensor and an assembly mechanism, the built-in data collector comprising a plurality of displacement measurement channels and a plurality of reserved measurement channels, the built-in displacement sensor comprising a plurality of displacement sensors, the plurality of displacement sensors of the built-in displacement sensor being respectively connected to the plurality of displacement measurement channels of the built-in data collector in a one-to-one correspondence, the built-in data collector and the built-in displacement sensor being fixedly arranged in the assembly mechanism; A material testing machine, the material testing machine includes a bracket, a base, a movable beam and a displacement measurement point, the base is fixedly arranged at the bottom of the bracket, the movable beam is movably connected to the bracket, the displacement measurement point is fixedly arranged on the bracket, the material testing machine also includes a calibration displacement sensor and a calibration force sensor, the calibration displacement sensor is parallel to the moving direction of the movable beam, the calibration force sensor is parallel to the loading force direction, the calibration displacement sensor and the calibration force sensor are respectively connected to the reserved measurement channels of the built-in data acquisition device in a one-to-one correspondence, the calibration force sensor is used to measure the loading force, and the calibration displacement sensor is used to measure the displacement of the movable scale relative to the displacement measurement point.

Images