Calibration method and device of six-dimensional force sensor

Abstract

The invention discloses a calibration method and device for a six-dimensional force sensor. The calibration method comprises the following specific steps: step 1, carrying out demand analysis and target setting on the six-dimensional force sensor; 2, calibrating the six-dimensional force sensor by using a simple calibration device; 3, a mapping relation model between input and output of the sensor is built through a machine learning algorithm or a statistical method, model input comprises force and torque in six directions, a composite loading data set containing force and torque in multiple directions is generated through simulation software or experimental data, and the generated composite loading data set is used for training the model; through the new calibration method combining the modern computer technology and the data processing method, the mapping relation between the input and the output of the sensor can be more accurately constructed, and the calibration precision is improved; a detailed calibration experiment scheme is designed, the accuracy and consistency of experiment data are ensured, and powerful support is provided for verifying and optimizing a new calibration method.

Description

Technical Field

[0001] The present invention belongs to the technical field of six-dimensional force sensors, and in particular relates to a calibration method and device for a six-dimensional force sensor. Background Art

[0002] The six-axis force sensor is a high-precision, multifunctional sensor that can simultaneously detect the force and torque of an object in three orthogonal directions. The reason why the six-axis force sensor needs to be calibrated is mainly to ensure measurement accuracy.

[0003] In actual use, traditional calibration methods may not be able to fully consider the interaction of forces and torques in multiple directions, resulting in a decrease in the measurement accuracy of the sensor under composite loading conditions and failure to meet the needs of high-precision measurement. If the experimental design is unreasonable or the data acquisition and processing methods are inappropriate, errors or inconsistencies may occur in the experimental data, thereby affecting the accuracy and reliability of the calibration results. The current calibration device requires multiple complex structures to detect all surfaces of the six-dimensional force sensor. The operation is relatively complicated and difficult, and it is not easy to maintain later. Summary of the invention

[0004] The object of the present invention is to provide a calibration method and device for a six-axis force sensor to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a calibration method for a six-dimensional force sensor, the specific steps are as follows:

[0006] Step 1: Analyze the needs and set goals for the six-dimensional force sensor;

[0007] Step 2: Use a simple calibration device to calibrate the six-dimensional force sensor;

[0008] Step 3: Use machine learning algorithms or statistical methods to build a mapping relationship model between sensor input and output. The model input includes forces and moments in six directions. Use simulation software or experimental data to generate a composite loading data set containing forces and moments in multiple directions. Use the generated composite loading data set to train the model and adjust the model parameters to minimize the prediction error.

[0009] Step 4: Design a variety of composite loading schemes to cover various force and torque combinations that the sensor may encounter; ensure that the loading method can accurately control the size, direction and change rate of the loading force and torque, and arrange the loading sequence: arrange the loading sequence reasonably according to the experimental purpose and calibration requirements, and use a high-precision data acquisition system to record the output data of the sensor under composite loading conditions; pre-process the collected data, including filtering, denoising, data alignment, etc., to ensure the accuracy and consistency of the data;

[0010] Step 5: Data processing and analysis: collect all data generated during the experiment, including load force / torque values ​​and sensor output signals, and pre-process the collected data, including data cleaning, data conversion, and data normalization; use statistical methods and machine learning algorithms to analyze and process the pre-processed data; extract useful information and features, and establish a mapping relationship model between sensor input and output.

[0011] Preferably, in step one, it is necessary to analyze the forces and moments in six directions of Fx, Fy, Fz, Mx, My, and Mz of the six-dimensional force sensor, and set a calibration accuracy target: etarget≤predetermined value.

[0012] Preferably, in step 2, the torque range of the simple calibration device is: F min ≤F≤F max , M min ≤M≤M max .

[0013] Preferably, in step three, a cross-validation technique is used to evaluate the generalization ability of the model, and the model is optimized based on the evaluation results; experimental verification is carried out on a calibration device by actually loading the composite force / torque and recording the sensor output data.

[0014] The present invention also discloses a calibration device for a six-dimensional force sensor, including a simple calibration device, which includes a base plate and an upper cover placed on the top of the base plate, wherein guide columns penetrate the four corners of the upper cover and the base plate; a force-applying component is installed on the opposite surfaces of the base plate and the upper cover.

[0015] Preferably, the force-applying assembly includes a placement ring fixed on the top end surface of the bottom plate and the bottom end surface of the upper cover, and airbags are arranged at equal angles inside the placement ring. Each airbag is connected to a connecting tube that passes through the outside of the placement ring, and the connecting tube is connected to an external air supply part. By injecting gas into the interior of the connecting tube, the connecting tube is made to bulge, and calibration and detection of the six-dimensional force sensor is achieved through the bulged connecting tube.

[0016] Preferably, the gas supply member comprises an annular air pipe sleeved on the outside of the placement ring, the annular air pipe is connected to the connecting pipe, and the outside of the annular air pipe is also connected to a gas injection pipe, through which gas injection is achieved.

[0017] Preferably, the gas injection pipe is also connected to a bellows, and through the setting of the bellows, the length of the bellows can be changed and can move synchronously with the upper cover.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The new calibration method, which combines modern computer technology and data processing methods, can more accurately construct the mapping relationship between sensor input and output and improve calibration accuracy. A detailed calibration experiment plan is designed to ensure the accuracy and consistency of experimental data, providing strong support for the verification and optimization of the new calibration method. Together, the two improve the calibration effect and performance evaluation reliability of the six-dimensional force sensor under composite loading conditions.

[0020] In the present invention, the airbag drive method is used to achieve comprehensive and accurate calibration and detection of each surface of the six-dimensional sensor. This method not only has a simple and clear structural design, avoiding complex mechanical structures, thereby reducing the complexity and maintenance costs of the overall system; but also in actual operation, the steps are simple and intuitive, without the need for tedious adjustment and calibration processes, greatly improving work efficiency. By inflating and deflating the airbag, forces and torques of different directions and magnitudes can be accurately applied to ensure that the six-dimensional sensor can obtain accurate calibration data in each dimension, thereby improving its measurement accuracy and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] Figure 2 A bottom view of the present invention;

[0023] Figure 3 It is a schematic diagram of the structure of the present invention when the upper cover is removed;

[0024] Figure 4 It is a schematic diagram of the connection between the annular air pipe and the air injection pipe of the present invention.

[0025] In the figure:

[0026] 100, bottom plate; 101, upper cover; 102, guide column;

[0027] 200, placement ring; 201, annular air tube; 202, connecting tube; 203, air bag; 204, air injection tube; 205, bellows. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figures 1 to 4 The present invention provides a technical solution: a calibration method for a six-dimensional force sensor, the specific steps are as follows:

[0030] Step 1: Analyze the needs and set goals for the six-dimensional force sensor;

[0031] Step 2: Use a simple calibration device to calibrate the six-dimensional force sensor;

[0032] Step 3: Use machine learning algorithms or statistical methods to build a mapping relationship model between sensor input and output. The model input includes forces and moments in six directions. Use simulation software or experimental data to generate a composite loading data set containing forces and moments in multiple directions. Use the generated composite loading data set to train the model and adjust the model parameters to minimize the prediction error.

[0033] Step 4: Design a variety of composite loading schemes to cover various force and torque combinations that the sensor may encounter; ensure that the loading method can accurately control the size, direction and change rate of the loading force and torque, and arrange the loading sequence: arrange the loading sequence reasonably according to the experimental purpose and calibration requirements, and use a high-precision data acquisition system to record the output data of the sensor under composite loading conditions; pre-process the collected data, including filtering, denoising, data alignment, etc., to ensure the accuracy and consistency of the data;

[0034] Step 5: Data processing and analysis: collect all data generated during the experiment, including load force / torque values ​​and sensor output signals, and pre-process the collected data, including data cleaning, data conversion, and data normalization; use statistical methods and machine learning algorithms to analyze and process the pre-processed data; extract useful information and features, and establish a mapping relationship model between sensor input and output.

[0035] In this embodiment, preferably, in step one, it is necessary to analyze the forces and moments in six directions of Fx, Fy, Fz, Mx, My, and Mz of the six-dimensional force sensor, and set a calibration accuracy target: etarget≤predetermined value.

[0036] In this embodiment, preferably, in step 2, the torque range of the simple calibration device is: F min ≤F≤F max , M min ≤M≤M max .

[0037] In this embodiment, preferably, in step three, a cross-validation technique is used to evaluate the generalization ability of the model, and the model is optimized based on the evaluation results; experimental verification is carried out on a calibration device by actually loading the composite force / torque and recording the sensor output data.

[0038] The present invention also discloses a calibration device for a six-dimensional force sensor, including a simple calibration device, which includes a base plate 100 and an upper cover 101 placed on the top of the base plate 100, wherein guide columns 102 penetrate the four corners of the upper cover 101 and the base plate 100; a force-applying component is installed on the opposite surfaces of the base plate 100 and the upper cover 101.

[0039] In this embodiment, preferably, the force-applying component includes a placement ring 200 fixed on the top surface of the base plate 100 and the bottom surface of the upper cover 101, and air bags 203 are arranged at equal angles inside the placement ring 200. Each air bag 203 is connected to a connecting tube 202 that passes through the outside of the placement ring 200. The connecting tube 202 is connected to an external air supply part. By injecting gas into the inside of the connecting tube 202, the connecting tube 202 is bulged, and the six-dimensional force sensor is calibrated and detected through the bulged connecting tube 202.

[0040] In this embodiment, preferably, the gas supply component includes an annular air pipe 201 sleeved on the outside of the placement ring 200, the annular air pipe 201 is connected to the connecting pipe 202, and the outside of the annular air pipe 201 is also connected to the gas injection pipe 204, and the gas injection is achieved through the gas injection pipe 204.

[0041] In this embodiment, preferably, the gas injection pipe 204 is also connected to a bellows 205 . Through the arrangement of the bellows 205 , the length of the bellows 205 can be changed, and the bellows 205 can move synchronously with the upper cover 101 .

[0042] Although embodiments of the present invention have been shown and described (see the above detailed description for details), it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A calibration method for a six-dimensional force sensor, characterized in that: The specific steps are as follows: Step 1: Analyze the needs and set goals for the six-dimensional force sensor; Step 2: Calibrate the six-dimensional force sensor using a calibration device; Step 3: Use machine learning algorithms or statistical methods to build a mapping relationship model between sensor input and output. The model input includes forces and moments in six directions. Use simulation software or experimental data to generate a composite loading data set containing forces and moments in multiple directions. Use the generated composite loading data set to train the model and adjust the model parameters to minimize the prediction error. Step 4: Design a variety of composite loading schemes to cover various force and torque combinations that the sensor may encounter; ensure that the loading method can accurately control the size, direction and change rate of the loading force and torque, and arrange the loading sequence: arrange the loading sequence reasonably according to the experimental purpose and calibration requirements, and use a high-precision data acquisition system to record the output data of the sensor under composite loading conditions; pre-process the collected data, including filtering, denoising, data alignment, etc., to ensure the accuracy and consistency of the data; Step 5: Data processing and analysis: collect all data generated during the experiment, including load force / torque values ​​and sensor output signals, and pre-process the collected data, including data cleaning, data conversion, and data normalization; use statistical methods and machine learning algorithms to analyze and process the pre-processed data; Extract useful information and features and establish a mapping relationship model between sensor input and output.

2. The calibration method of a six-dimensional force sensor according to claim 1, characterized in that: In the step 1, it is necessary to analyze the forces and moments in the six directions of Fx, Fy, Fz, Mx, My, and Mz of the six-dimensional force sensor, and set a calibration accuracy target: etarget≤predetermined value.

3. The calibration method of a six-dimensional force sensor according to claim 1, characterized in that: In step 2, the torque range of the calibration device is: F min ≤F≤F max , M min ≤M≤M max .

4. The calibration method of a six-dimensional force sensor according to claim 1, characterized in that: In the step three, a cross-validation technique is used to evaluate the generalization ability of the model, and the model is optimized based on the evaluation results; experimental verification is carried out on a calibration device by actually loading the composite force / torque and recording the sensor output data.

5. A calibration device for a six-dimensional force sensor, comprising the simple calibration device used in the calibration method according to any one of claims 1 to 4, characterized in that: The device comprises a base plate (100) and an upper cover (101) placed on the top of the base plate (100), wherein guide pillars (102) penetrate through the four corners of the upper cover (101) and the base plate (100); and a force-applying component is installed on the opposite surfaces of the base plate (100) and the upper cover (101).

6. A six-dimensional force sensor calibration device according to claim 5, characterized in that: The force-applying assembly comprises a placement ring (200) fixedly mounted on the top end surface of the bottom plate (100) and the bottom end surface of the upper cover (101), air bags (203) being arranged at equal angles inside the placement ring (200), each air bag (203) being connected to a connecting pipe (202) penetrating to the outside of the placement ring (200), and the connecting pipe (202) being connected to an external air supply component.

7. The six-dimensional force sensor calibration device according to claim 6, characterized in that: The gas supply component comprises an annular gas pipe (201) sleeved on the outside of the placement ring (200), the annular gas pipe (201) is connected to the connecting pipe (202), and the outside of the annular gas pipe (201) is also connected to the gas injection pipe (204).

8. The six-dimensional force sensor calibration device according to claim 7, characterized in that: The gas injection pipe (204) is also connected to a bellows (205).

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