Sensor calibration device capable of applying variable force without movement and calibration method thereof

Abstract

The invention discloses a sensor calibration device capable of applying variable force without movement and a calibration method thereof. The sensor calibration device comprises an adjusting assembly and a measuring assembly, an electromagnet and a lifting unit are arranged in the adjusting unit, and a magnetic part connected with a calibrated sensor and a bearing part for bearing the calibrated sensor are arranged in the measuring assembly; the magnetic piece is directly or indirectly connected with a calibrated sensor; the electromagnet can be far away from or close to the magnetic piece under the action of the lifting unit, and the magnetic piece can apply variable force to the calibrated sensor fixed on the bearing piece under the action of the electromagnet; according to the scheme, the calibrated sensor is fixed on the bearing piece all the time, the position of the calibrated sensor does not change or shake along with the action of applied force, and therefore the influence of mechanical motion on calibration of the calibrated sensor can be avoided, meanwhile, the calibrated sensor is applied with force in a magnetic attraction mode, and the calibration accuracy is improved. And more accurate, stable and efficient force application calibration can be realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of force sensor detection, and particularly relates to a sensor calibration device for applying variable force without motion and a calibration method thereof. BACKGROUND

[0002] In the technical field of force sensor calibration, existing calibration devices and methods mainly follow two technical paths of static force calibration and dynamic force calibration. Static force calibration is usually performed under stable and constant load, and it is difficult to accurately reflect the performance of the sensor when it bears dynamic changing force in real working conditions. Therefore, dynamic force calibration technology has been developed, and its commonly used methods mainly include impact method and sinusoidal vibration method. The calibration device of the impact method usually uses a lifting mechanism to lift a drop hammer or a moving beam to a certain height and then releases it, so that it freely falls and hits the sensor, thereby generating a transient impact force signal. The sinusoidal vibration method relies on a standard vibration table to drive a known mass block to generate an alternating inertia force, and a laser interferometer or other devices are used for accurate measurement. However, in the physical process of applying variable force, both of these two mainstream dynamic calibration methods inevitably cause significant mechanical motion or vibration of the sensor mounting base or the sensor itself. For some force sensors that are extremely sensitive to vibration, this additional motion introduced during calibration itself becomes a source of interference, which may excite unnecessary structural resonance of the sensor or introduce measurement noise, thereby distorting the calibration results and making it difficult to separate the real dynamic response of the sensor from the vibration interference caused by the calibration device.

[0003] In addition, although existing multi-dimensional force sensor calibration systems attempt to compensate for the coupling interference between loading forces in different directions through complex servo-hydraulic control and monitoring systems, their core loading mechanisms still rely on physical motion or displacement, and they have not fundamentally solved the vibration problem caused by motion. Some improved schemes increase the buffer protection mechanism or safety grating to improve the safety of the equipment, or use vibration isolation and frequency increasing mechanisms to try to increase the system resonance frequency, but these measures are all post-vibration reduction or local optimization, and they do not change the essence of the calibration device based on mechanical motion to generate dynamic force. Therefore, there has been a long-standing technical problem in the industry that has not been completely solved: how to apply precise and controllable dynamic calibration force while minimizing or even eliminating the vibration transmission caused by the motion of the calibration device execution components, to provide an ideal calibration environment for vibration-sensitive force sensors that is nearly free of motion interference, and to ensure the accuracy and reliability of the calibration results. SUMMARY

[0004] The present application aims to provide a sensor calibration device for applying variable force without motion and a calibration method thereof to solve the problem that the detection and setting of force sensors will produce unnecessary noise due to mechanical motion, affecting the calibration accuracy of force sensors.

[0005] The present application is realized by the following scheme: The present application is realized by the following scheme:

[0006] Based on the above-mentioned sensor calibration device without motion to apply variable force, the lifting unit is one of lifting motor, lifting oil cylinder, lifting air cylinder or electric telescopic rod, and the electromagnet is arranged on the moving end of the lifting unit.

[0007] Based on the above-mentioned sensor calibration device without motion to apply variable force, the lifting unit includes a lifting motor and a motor support plate, the output end of the lifting motor is arranged upward, the lifting motor is fixedly arranged in the motor support plate, the electromagnet is arranged on the output end of the lifting motor, the electromagnet is arranged at the center position of the magnetic member, and the lifting motor specifically adopts a stepping motor.

[0008] Based on the above-mentioned sensor calibration device without motion to apply variable force, the receiving member includes a support base, a force transmission support plate and a sensor support plate, the force transmission support plate is arranged on the support base through a first support rod, the sensor support rod is arranged on the force transmission support plate through a second support rod, the calibrated sensor is arranged on the sensor support plate, and a through hole is arranged on the force transmission support plate for the output part of the lifting unit to pass through.

[0009] Based on the above-mentioned sensor calibration device without motion to apply variable force, the first support rod is arranged between the support base and the force transmission support plate to form a frame structure, and the lifting unit is arranged in the frame structure formed by the first support rod; the second support rod is arranged between the force transmission support plate and the sensor support plate to form a frame structure, and the electromagnet and the magnetic member are arranged in the frame structure formed by the second support rod.

[0010] Based on the above-mentioned sensor calibration device without motion to apply variable force, the magnetic member is specifically a magnetic metal block, and the electromagnet is collinear with the central axis of the magnetic metal block.

[0011] Based on the above-mentioned sensor calibration device without motion to apply variable force, a third supporting rod is connected to the magnetic metal block, and the magnetic metal block is connected with the counterweight supporting plate through a third supporting pipe; a standard force sensor is arranged on the sensor to be calibrated, and the standard force sensor is in contact with the lower end surface of the counterweight supporting plate; a through hole is arranged on the sensor supporting plate for the third supporting rod to penetrate.

[0012] Based on the above-mentioned sensor calibration device without motion to apply variable force, a counterweight block is further arranged on the counterweight supporting plate.

[0013] The present application also provides a calibration method of a sensor without motion to apply variable force, comprising the following steps: Step one, energize the electromagnet, and start the stepping motor to make the electromagnet close to the magnetic metal block; Step two, judge whether the electromagnet and the magnetic metal block are in contact; if the electromagnet and the magnetic metal block are in contact, repeat step one; if the electromagnet and the magnetic metal block are not in contact, proceed to step three; Step three, keep a predetermined time according to the experimental requirements to realize the calibration of the force sensor.

[0014] In step two, the method for judging whether the electromagnet and the magnetic metal block are in contact is as follows: When the electromagnet is not energized, the pre-tightening compression force received by the standard force sensor is: F2= M1+M3+M4+M5 When F2 < M1+M3+M4+M5, the gap between the electromagnet and the magnetic metal block is 0; when F2=M1+M3+M4+M5, there is a gap between the electromagnet and the magnetic metal block; the mass of the magnetic metal block is M1, the mass of the counterweight block supporting plate is M 3, , the mass of the counterweight block is M 4, , and the total mass of the column connecting the magnetic metal block and the sensor supporting plate is M5.

[0015] Based on the above-mentioned sensor calibration device without motion to apply variable force, the support base is in a circular structure, a film accommodating cavity is arranged at the center of the support base and is collinear with the center of the support base, and a matching hole for cooperating with a fixing part is uniformly arranged at the circumferential position of the film accommodating cavity; the shape and size of the film accommodating cavity are matched with the piezoelectric film.

[0016] As described above, due to the adoption of the above technical solutions, the present application has the following advantages: 1) In this solution, the sensor under calibration is always fixed on the receiving component and will not change position or shake when force is applied. This avoids the influence of mechanical movement on the calibration of the sensor under calibration. At the same time, this solution applies force to the sensor under calibration by magnetic attraction, which can achieve more accurate, stable and efficient force calibration. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention; Reference numerals: 1. Adjustment component; 2. Measuring component; 3. Sensor under calibration; 4. Standard force sensor; 5. Counterweight; 11. Electromagnet; 12. Lifting unit; 21. Magnetic component; 22. Receiving component; 121. Lifting motor; 122. Motor support plate; 221. Support base; 222. Force transmission support plate; 223. Sensor support plate; 224. First support rod; 225. Second support rod; 226. Third support rod; 227. Counterweight support plate. Detailed Implementation

[0018] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0019] Any feature disclosed in this specification (including any appended claims and abstract) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0020] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a predetermined orientation, or be constructed and operated in a predetermined orientation. Therefore, they should not be construed as limitations on this invention.

[0021] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0022] Example 1 like Figure 1 As shown, the present invention provides a technical solution: The application discloses a sensor calibration device without motion exerting variable force, which comprises an adjusting assembly 1 and a measuring assembly 2; an electromagnet 11 and a lifting unit 12 are arranged in the adjusting unit; a magnetic piece 21 connected with a sensor 3 to be calibrated and a receiving piece 22 for receiving the sensor 3 to be calibrated are arranged in the measuring assembly 2; the magnetic piece 21 is directly or indirectly connected with the receiving sensor 3; the electromagnet 11 can move away from or close to the magnetic piece 21 under the action of the lifting unit 12, and the magnetic piece 21 can exert variable force on the sensor 3 to be calibrated fixed on the receiving piece 22 under the movement of the electromagnet 11.

[0023] Based on the above structure, the sensor 3 to be calibrated is always fixed on the receiving piece 22 and cannot change position or shake under the action of force exertion, so that the influence of mechanical movement on calibration of the sensor 3 to be calibrated can be avoided, and the sensor 3 to be calibrated can be exerted force by magnetic attraction, so that the force exertion, calibration and the like can be more accurate, stable and efficient.

[0024] As an example, the lifting unit 12 is one of a lifting motor 121, a lifting oil cylinder, a lifting air cylinder or an electric telescopic rod, and the electromagnet 11 is arranged on a movement end of the lifting unit 12.

[0025] Based on the above structure, the lifting function of the electromagnet 11 can be realized by the lifting motor 121, the lifting oil cylinder, the lifting air cylinder or the electric telescopic rod.

[0026] As an example, the lifting unit 12 can comprise the lifting motor 121 and a motor support plate 122, an output end of the lifting motor 121 is arranged upward, the lifting motor 121 is fixedly arranged in the motor support plate 122, the electromagnet 11 is arranged on the output end of the lifting motor 121, the electromagnet 11 is arranged at a center position of the magnetic piece 21, and the lifting motor 121 can be a stepping motor.

[0027] Based on the above structure, the lifting motor 121 can accurately and efficiently realize the lifting movement of the electromagnet 11, accurately adjust the gap between the electromagnet 11 and the magnetic piece 21, and realize the size adjustment of the magnetic force.

[0028] As an example, the receiving piece 22 can comprise a support base 221, a force transmission support plate 222 and a sensor support plate 223; the force transmission support plate 222 is arranged on the support base 221 through a first support rod 224, the sensor support plate 223 is arranged on the force transmission support plate 222 through a second support rod 225, and the sensor 3 to be calibrated is arranged on the sensor support plate 223.

[0029] A through hole through which an output part of the lifting unit 12 passes is arranged on the force transmission support plate 222.

[0030] The first support rods 224 are arranged between the support base 221 and the force transmission support plate 222, and are four in number, forming a frame structure, and the lifting unit 12 is arranged in the frame structure formed by the first support rods 224; The second support rods 225 are arranged between the force transmission support plate 222 and the sensor support plate 223, and are four in number, forming a frame structure, and the electromagnet 11 and the magnetic member 21 are arranged in the frame structure formed by the second support rods 225.

[0031] Based on the above structure, the to-be-calibrated sensor 3 is fixed by the support, the first support rods 224 form a space for the lifting unit 12, and the second support rods 225 form a space for the electromagnet 11 and the magnetic member 21, facilitating the calibration operation.

[0032] As an example, the magnetic member 21 can be a magnetic metal block, and the electromagnet 11 is collinear with the central axis of the magnetic metal block.

[0033] Based on the above structure, when the electromagnet 11 is energized, the magnetic metal block can be provided with balanced magnetic force, making the calibration experiment more efficient.

[0034] As an example, the magnetic metal block is connected with a third support rod 226, and the magnetic metal block is connected with the counterweight support plate 227 through the third support rod 226; a standard force sensor 4 is arranged on the to-be-calibrated sensor 3, the standard force sensor 4 is in contact with the lower end surface of the counterweight support plate 227; and a through hole is arranged on the sensor support plate 223 for the third support rod 226 to pass through.

[0035] Based on the above structure, the magnetic metal block is in contact with the standard force sensor 4 through the third support rod 226 and the counterweight support plate, realizing force transmission, and the standard force sensor 4 is in contact with the to-be-calibrated sensor 3, realizing force output.

[0036] As an example, the counterweight block 5 can also be arranged on the counterweight support plate 227.

[0037] Based on the above structure, due to the manufacturing and assembly errors of the parts, there may be uneven gaps between the electromagnet 11 and the magnetic metal block. In the instant of energization of the electromagnet 11, the uneven gaps will cause uneven magnetic force, causing the force measuring device to tilt and increasing the measurement error. The function of the counterweight block 5 is to force the magnetic metal block to keep horizontal with the force measuring device, and the mass of the counterweight block 5 should be determined according to the torque balance relationship of the magnetic metal block keeping horizontal without magnetic force.

[0038] When the electromagnet 11 is energized, the magnetic metal block will have a downward movement tendency under the action of magnetic force.

[0039] At this time, the counterweight block 5, which is fixed to it, is subjected to a downward pulling force. This pressure is transmitted step by step to the standard force sensor 4, the force sensor being calibrated, and the sensor support plate 223. The sensor support plate 223 is fixedly connected to the force transmission support plate 222, which is fixedly connected to the base. Therefore, the sensor support plate 223 and the force transmission support plate 222 remain stationary. It can be seen that there is a linear correlation between the magnetic attraction force on the magnetic metal block and the pressure on the sensor.

[0040] Let the magnetic attraction force on the magnetic metal block be F1, its mass be M1, the mass of the standard force sensor be M2, the mass of the counterweight 5 support plate be M3, the mass of the counterweight 5 be M4, and the total mass of the column connecting the magnetic metal block and the sensor support plate 223 be M5.

[0041] When electromagnet 11 is not energized, the preload compression force F2 on standard force sensor 4 is: F2 = M1 + M3 + M4 + M5 When electromagnet 11 is energized, the pressure F3 experienced by standard force sensor 4 is: F3 = F2 + F1 At this moment, the pressure F4 exerted on the force sensor being calibrated is: F4 = F3 + M2 = M1 + M3 + M4 + M5 + F1 + M2 Among them, M1, M2, M3, M4, and M5 are fixed values. It can be seen that by adjusting the value of F1 (adjusted by changing the power supply voltage of electromagnet 11), a varying pressure value can be applied to the standard force sensor 4 and the force sensor under calibration. During calibration, the actual pressure on the force sensor under calibration can be calculated by comparing the output of the standard force sensor 4, thus enabling calibration.

[0042] During the application of magnetic force, the gap between the electromagnet 11 and the magnetic metal block needs to be controlled. It must be ensured that they do not come into contact; otherwise, the electromagnet 11 will exert a vertically upward supporting force F on the magnetic metal block. s The magnitude of this supporting force cannot be directly calculated, thus preventing the application of variable forces. Simultaneously, the gap between the electromagnet 11 and the magnetic metal block cannot be too large; otherwise, no magnetic attraction will be generated, or the magnetic attraction will be very weak. Typically, this gap needs to be less than 0.5mm. This gap can be infinitely adjusted by the displacement of the telescopic rod at the top of the stepper motor.

[0043] Example 2 Based on the device of Embodiment 1 above, the present invention provides a technical solution: A calibration method for a sensor that applies a variable force without motion, comprising the following steps: Step 1: Power on electromagnet 11 and start the stepper motor to bring electromagnet 11 close to the magnetic metal block. Step two, judge whether the electromagnet 11 and the magnetic metal block contact; if the electromagnet 11 and the magnetic metal block contact, repeat step one; if the electromagnet 11 and the magnetic metal block do not contact, proceed to step three; Step three, keep the predetermined time according to the experimental requirements to realize the calibration for the force sensor.

[0044] In step one, the gap between the electromagnet 11 and the magnetic metal block is less than 0.5mm.

[0045] In step two, the method of judging whether the electromagnet 11 and the magnetic metal block contact is as follows: When the electromagnet 11 is not electrified, the pre-tightening compression force of the standard force sensor is: F2=M1+M3+M4+M5 When F2

[0046] The above only describes the preferred embodiments of the present application and is not used to limit the present application, any modification, equivalent replacement and improvement within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A sensor calibration device that applies a variable force without motion, characterized in that, The device includes an adjustment assembly (1) and a measurement assembly (2). The adjustment assembly is equipped with an electromagnet (11) and a lifting unit (12). The measurement assembly (2) is equipped with a magnetic component (21) connected to the sensor under test (3) and a receiving component (22) for receiving the sensor under test (3). The magnetic component (21) is directly or indirectly connected to the receiving sensor under test (3). The electromagnet (11) can move away from or closer to the magnetic component (21) under the action of the lifting unit (12). The magnetic component (21) can apply a changing force to the sensor under test (3) fixed on the receiving component (22) under the movement of the electromagnet (11).

2. The sensor calibration device for applying variable force without motion according to claim 1, characterized in that: The lifting unit (12) is one of the following: lifting motor (121), lifting cylinder, lifting air cylinder or electric telescopic rod, and the electromagnet (11) is installed on the moving end of the lifting unit (12).

3. The sensor calibration device for applying variable force without motion according to claim 1, characterized in that: The lifting unit (12) includes a lifting motor (121) and a motor support plate (122). The output end of the lifting motor (121) is set upward. The lifting motor (121) is fixedly set in the motor support plate (122). The electromagnet (11) is set on the output end of the lifting motor (121). The electromagnet (11) is set at the center of the magnetic component (21). The lifting motor (121) is specifically a stepper motor.

4. The sensor calibration device for applying variable force without motion according to claim 3, characterized in that: The receiving component (22) includes a support base (221), a force transmission support plate (222), and a sensor support plate (223); the force transmission support plate (222) is mounted on the support base (221) via a first support rod (224), the sensor support rod is mounted on the force transmission support plate (222) via a second support rod (225), and the calibrated sensor (3) is mounted on the sensor support plate (223); a through hole is provided on the force transmission support plate (222) for the output part of the lifting unit (12) to pass through.

5. The sensor calibration device for applying variable force without motion according to claim 4, characterized in that: The first support rod (224) is set in four between the support base (221) and the force transmission support plate (222) to form a frame structure, and the lifting unit (12) is set in the frame structure formed by the first support rod (224); the second support rod (225) is set in four between the force transmission support plate (222) and the sensor support plate (223) to form a frame structure, and the electromagnet (11) and magnetic component (21) are set in the frame structure formed by the second support rod (225).

6. The sensor calibration device for applying variable force without motion according to claim 5, characterized in that: The magnetic component (21) is specifically a magnetic metal block, and the electromagnet (11) is collinear with the central axis of the magnetic metal block.

7. The sensor calibration device for applying a variable force without motion according to claim 6, characterized in that: A third support rod (226) is connected to the magnetic metal block, and the magnetic metal block is connected to the counterweight support plate (227) through the third support tube; a standard force sensor (4) is provided on the sensor to be calibrated (3), and the standard force sensor (4) is in contact with the lower end face of the counterweight support plate (227); a through hole is provided on the sensor support plate (223) for the third support rod (226) to pass through.

8. The sensor calibration device for applying a variable force without motion according to claim 7, characterized in that: The counterweight support plate (227) is also provided with a counterweight block (5).

9. A calibration method for a sensor that applies a variable force without motion, based on the calibration device according to any one of claims 1 to 8, characterized in that: Includes the following steps: Step 1: Power on the electromagnet (11) and start the stepper motor to bring the electromagnet (11) close to the magnetic metal block; Step 2: Determine whether there is contact between the electromagnet (11) and the magnetic metal block; if the electromagnet (11) and the magnetic metal block are in contact, repeat step 1; if the electromagnet (11) and the magnetic metal block are not in contact, proceed to step 3. Step 3: Perform calibration of the force sensor by maintaining the position for the predetermined time according to experimental requirements.

10. The calibration method for a sensor that applies a variable force without motion, as described in claim 9, is characterized in that: In step two, the method for determining whether there is contact between the electromagnet (11) and the magnetic metal block is as follows: When the electromagnet (11) is not energized, the preload force on the standard force sensor (4) is: F2 = M1 + M3 + M4 + M5 When F2 < M1 + M3 + M4 + M5, the gap between the electromagnet (11) and the magnetic metal block is 0; when F2 = M1 + M3 + M4 + M5, there is a gap between the electromagnet (11) and the magnetic metal block; the mass of the magnetic metal block is M1, and the mass of the counterweight support plate is M. 3, The mass of the counterweight is M 4, The total mass of the column connecting the magnetic metal block and the sensor support plate is M5.

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