Calibration method and calibration system of force sensor, electronic device and storage medium

Abstract

The application provides a force sensor calibration method, a calibration system, an electronic device and a storage medium, and relates to the technical field of sensor calibration. The method comprises the following steps: determining r, R0, G0, L1, L3, L4, L6, L7 and L8; determining the initial position angle a0 of a cradle, setting the theoretical force value F0 of a screw motor to 0, and recording the sampling value S0 of a force sensor; controlling the cradle to rotate, the number of rotations is n, the rotation angle of each rotation is Delta a i , and the current position angle a i of each rotation is recorded; according to G0, L1, L6, L7, L8 and a i , the theoretical force value F i is calculated, and the sampling value S i is recorded; the linearity of n+1 calibration points is evaluated; if the calibration points are available, the calibration of the force sensor is completed; if the calibration points are unavailable, the calibration points are reacquired and the linearity is evaluated. In the technical scheme of the application, the availability evaluation means of the calibration points is provided by adding several calibration points, which is beneficial to identifying the calibration error and significantly improving the calibration precision.

Description

Technical Field

[0001] This invention relates to the field of sensor calibration technology, and more specifically, to a calibration method, calibration system, electronic device, and storage medium for a force sensor. Background Technology

[0002] The back pressure control system of the winding machine consists of a screw motor, a force sensor, and an angle sensor. During its use, the force sensor needs to be calibrated. Due to the special mechanical structure of the back pressure control system of the winding machine, if the existing calibration tools are used to calibrate the sensor on site, the calibration process is complicated, requires a lot of manpower, and has disadvantages such as inaccurate calibration and the need for auxiliary tools.

[0003] In related technologies, a two-point calibration method is used to calibrate force sensors, which involves sampling data from only two locations. While this calibration method can partially solve the aforementioned problems, it suffers from poor stability, is prone to deviations in calibration results, and its accuracy is difficult to guarantee. Summary of the Invention

[0004] In order to solve or improve the technical problems of poor stability, easy deviation of calibration results, and difficulty in guaranteeing accuracy of the two-point calibration method, one objective of the present invention is to provide a calibration method for force sensors.

[0005] Another object of the present invention is to provide a calibration system for a force sensor.

[0006] Another object of the present invention is to provide an electronic device.

[0007] Another object of the present invention is to provide a readable storage medium.

[0008] To achieve the above objectives, the first aspect of the present invention provides a calibration method for a force sensor used in a winding machine back pressure control system. The winding machine back pressure control system includes a friction roller, a yarn bobbin, a rocker arm, a slider, a screw motor, an angle sensor, and a force sensor. The friction roller is rotatably connected to a first fulcrum, the rocker arm is rotatably connected to a second fulcrum, and the screw motor is rotatably connected to a third fulcrum. The screw motor has a rotatable screw, and the slider is rotatably mounted on the screw. The rocker arm has a first end and a second end opposite to each other. The first end is rotatably connected to the yarn bobbin, which is in frictional engagement with the friction roller, and the second end is rotatably connected to the slider. The angle sensor is mounted on the rocker arm and is used to obtain the position angle of the rocker arm. The force sensor is mounted on the screw motor and is used to obtain the actual force value of the screw motor. The screw motor drives the screw to rotate, thereby changing the relative position of the slider and the screw, causing the yarn bobbin and the rocker arm to rotate relative to each other.

[0009] The calibration method includes: determining the initial parameters of the back pressure control system of the winding machine, including the radius r of the friction roller, the radius R0 of the yarn bobbin in the empty state, the weight G0 of the yarn bobbin and the cradle in the empty state, the distance L1 between the second support point and the first end, the horizontal distance L3 between the first support point and the second support point, the vertical distance L4 between the first support point and the second support point, the distance L6 between the second support point and the second end, the vertical distance L7 between the second support point and the third support point, and the horizontal distance L8 between the second support point and the third support point; determining the initial position angle α0 of the cradle when the yarn bobbin is empty and the yarn bobbin and the friction roller are relatively stationary, recording the theoretical force value F0 of the screw motor as 0, and recording the sampled value S0 of the force sensor; controlling the cradle to rotate, the number of rotations is n, and the rotation angle of each rotation is Δα. i Record the current position angle of the cradle after each rotation as α. i According to G0, L1, L6, L7, L8 and α i Calculate the theoretical force F of the screw motor. i Record the sampled value S of the force sensor. i ; where α i =α i-1 +Δα i , 1≤i≤n, n≥2; using the theoretical force value as the abscissa and the sampled value as the ordinate, determine n+1 calibration points (0, S0), (F) in the spatial coordinate system. i S i ), (F n S n Alternatively, using sampled values ​​as the x-axis and theoretical force values ​​as the y-axis, determine n+1 calibration points (S0, 0), (S...) in the spatial coordinate system. i F i ), (S n F n ); linearity is evaluated at n+1 calibration points to determine their usability; where F n The theoretical force value of the screw motor when i = n; S n When i = n, the sampled value of the force sensor is obtained; if the calibration point is available, the linear relationship between the theoretical force value and the sampled value is determined, and the force sensor is calibrated; if the calibration point is unavailable, n+1 calibration points are obtained again and the linearity is evaluated again.

[0010] The present invention aims to provide a calibration method for force sensors, which can complete the calibration of force sensors without the aid of auxiliary tools. The calibration process is simple, quick, and highly accurate, which helps to reduce labor costs.

[0011] Furthermore, this method adds several calibration points to the previous two-point calibration method. By continuously moving the cradle during the new calibration process, random disturbances in the mechanical state during the calibration process can be detected, and quantitative evaluation basis can be provided for the calibration results. This allows for reasonable evaluation of the calibration results, effective identification of calibration errors, significant improvement of calibration accuracy, and greatly improved operation performance of the entire mechanism.

[0012] It should be noted that if the calibration error is considered too large (or the calibration points are unavailable), the calibration should be performed again following the steps described above to obtain n+1 calibration points. This method facilitates a "self-check" function, thereby ensuring the accuracy of the calibration results.

[0013] In some technical solutions, optionally, the linearity of n+1 calibration points is evaluated to determine whether the calibration points are available, including: evaluating the linearity of n+1 calibration points based on the least squares method and / or the endpoint connection method to determine whether the calibration points are available.

[0014] In this technical solution, if the linearity is deemed good, the fitted straight line is used as the calibration curve to complete the calibration; if the linearity is deemed poor, the steps of obtaining calibration points and evaluating the fit must be repeated until the linearity meets the requirements. This approach facilitates a "self-checking" function, thereby ensuring the accuracy of the calibration results.

[0015] In some technical solutions, optionally, linearity evaluation is performed on n+1 calibration points based on the least squares method and / or the endpoint connection method to determine whether the calibration points are usable. This includes: determining a fitted line based on the n+1 calibration points and the least squares method, where the sum of the squared vertical distances from the n+1 calibration points to the fitted line is minimized; calculating the correlation coefficient γ based on the n+1 calibration points and the fitted line; and determining that the calibration points are usable if the absolute value of the correlation coefficient γ is greater than or equal to a preset threshold.

[0016] In this technical solution, the use of the least squares method helps optimize the overall fitting effect of all calibration points and effectively suppresses the influence of random mechanical disturbances on the calibration results. Furthermore, comparing the absolute value of the correlation coefficient γ with a preset threshold helps improve the accuracy of the calibration results.

[0017] In some technical solutions, optionally, linearity evaluation is performed on n+1 calibration points based on the least squares method and / or the endpoint connection method to determine whether the calibration points are available. It also includes determining that the calibration points are unavailable if the absolute value of the correlation coefficient γ is less than a preset threshold.

[0018] In this technical solution, if the absolute value of the correlation coefficient γ is less than a preset threshold, the linearity is deemed poor, and the steps of obtaining calibration points and evaluating the fit must be repeated until the linearity meets the requirements. This approach facilitates a "self-checking" function, thereby ensuring the accuracy of the calibration results.

[0019] In some technical solutions, optionally,

[0020]

[0021] Among them, F i It can be any one of multiple theoretical force values; S is the average of multiple theoretical force values. i For any one of the multiple sample values, It is the average of multiple sampled values.

[0022] In this technical solution, comparing the absolute value of the correlation coefficient γ with a preset threshold helps to improve the accuracy of the calibration results.

[0023] In some technical solutions, α can optionally be used. i Less than 90 degrees.

[0024] In this technical solution, by limiting α i The range of values ​​has two main benefits. First, it prevents the cradle from interfering with the movement of other components or devices, thus improving the safety performance of the system. Second, it ensures that the force sensor collects sampling values ​​within its linear operating range, avoiding signal distortion caused by excessive angles and reducing the interference of nonlinear errors on the fitting results.

[0025] In some technical solutions, the initial position angle α0 of the cradle can be obtained by an angle sensor, or the initial position angle α0 of the cradle can be calculated based on r, R0, L1, L3 and L4.

[0026] In this technical solution, the direct measurement by the angle sensor and the parameter calculation complement each other, avoiding calibration interruptions caused by the failure of a single method (such as α0 can still be obtained through calculation when the sensor is damaged), giving the system redundancy and fault tolerance capabilities, and adapting to complex industrial environments.

[0027] A second aspect of the present invention provides a calibration system for a force sensor, comprising: an initial parameter determination unit for determining initial parameters of the back pressure control system of a winding machine, the initial parameters including the radius r of the friction roller, the radius R0 of the yarn bobbin in an empty state, the weight G0 of the yarn bobbin and the cradle in an empty state, the distance L1 between the second fulcrum and the first end, the horizontal distance L3 between the first fulcrum and the second fulcrum, the vertical distance L4 between the first fulcrum and the second fulcrum, the distance L6 between the second fulcrum and the second end, the vertical distance L7 between the second fulcrum and the third fulcrum, and the horizontal distance L8 between the second fulcrum and the third fulcrum; a first data processing unit for determining the initial position angle α0 of the cradle when the yarn bobbin is in an empty state and the yarn bobbin and the friction roller are relatively stationary, recording the theoretical force value F0 of the screw motor as 0, and recording the sampled value S0 of the force sensor; and a control and calculation unit for controlling the cradle to rotate, the number of rotations being n, and the rotation angle of each rotation being Δα. i Record the current position angle of the cradle after each rotation as α. i According to G0, L1, L6, L7, L8 and α i Calculate the theoretical force F of the screw motor. i Record the sampled value S of the force sensor. i ; where α i =α i-1 +Δα i , 1≤i≤n, n≥2; The second data processing unit is used to determine n+1 calibration points (0, S0), (F) in the spatial coordinate system with the theoretical force value as the abscissa and the sampled value as the ordinate. i S i ), (F n S n Alternatively, using sampled values ​​as the x-axis and theoretical force values ​​as the y-axis, determine n+1 calibration points (S0, 0), (S...) in the spatial coordinate system. i F i ), (S n F n ); linearity is evaluated at n+1 calibration points to determine their usability; where F n The theoretical force value of the screw motor when i = n; S n When i = n, the sampled value of the force sensor; the third data processing unit is used to determine the linear relationship between the theoretical force value and the sampled value when the calibration point is available, and to complete the calibration of the force sensor; when the calibration point is not available, n+1 calibration points are reacquired and the linearity is evaluated again.

[0028] The present invention aims to provide a calibration system for force sensors, which can complete the calibration of force sensors without the aid of auxiliary tools. The calibration process is simple, fast, and accurate, which helps to reduce labor costs.

[0029] In addition, based on the previous two-point calibration method, the system adds several calibration points. By continuously moving the cradle during the new calibration process, random disturbances in the mechanical state during the calibration process can be detected, and quantitative evaluation basis can be provided for the calibration results. Thus, the calibration results can be reasonably evaluated, calibration errors can be effectively identified, calibration accuracy can be significantly improved, and the overall operating performance of the mechanism can be greatly improved.

[0030] It should be noted that if the calibration error is considered too large (or the calibration points are unavailable), the calibration should be performed again following the steps described above to obtain n+1 calibration points. This method facilitates a "self-check" function, thereby ensuring the accuracy of the calibration results.

[0031] A third aspect of the present invention provides an electronic device, comprising: a memory and a processor, wherein the memory stores a program or instructions executable on the processor, and the processor, when executing the program or instructions, implements the steps of the force sensor calibration method in any of the above-described technical solutions. The electronic device possesses the beneficial effects of any of the above-described technical solutions, which will not be elaborated further here.

[0032] A fourth aspect of the present invention provides a readable storage medium storing a program or instructions that, when executed by a processor, implement the steps of the force sensor calibration method in any of the above-described technical solutions. The readable storage medium possesses the beneficial effects of any of the above-described technical solutions, which will not be elaborated further here.

[0033] Additional aspects and advantages of the technical solutions of the present invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0034] Figure 1 A schematic diagram of a winding machine back pressure control system according to an embodiment of the present invention is shown;

[0035] Figure 2 A flowchart illustrating a calibration method for a force sensor according to an embodiment of the present invention is shown;

[0036] Figure 3 A flowchart illustrating a calibration method for a force sensor according to another embodiment of the present invention is shown;

[0037] Figure 4 A flowchart illustrating a calibration method for a force sensor according to another embodiment of the present invention is shown;

[0038] Figure 5 A structural block diagram of a calibration system for a force sensor according to an embodiment of the present invention is shown;

[0039] Figure 6 A structural block diagram of an electronic device according to an embodiment of the present invention is shown.

[0040] in, Figures 1 to 6 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0041] 100: Winding machine back pressure control system; 110: Friction roller; 120: Yarn bobbin; 130: Cradle; 131: First end; 132: Second end; 140: Slider; 150: Screw motor; 151: Screw; 161: Angle sensor; 162: Force sensor; 171: First fulcrum; 172: Second fulcrum; 173: Third fulcrum; 300: Force sensor calibration system; 310: Initial parameter determination unit; 320: First data processing unit; 340: Control and calculation unit; 350: Second data processing unit; 360: Third data processing unit; 400: Electronic equipment; 410: Memory; 420: Processor. Detailed Implementation

[0042] To better understand the above-described objectives, features, and advantages of the embodiments of the present invention, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0043] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, embodiments of the invention may be implemented in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0044] The following reference Figures 1 to 6 This invention describes a calibration method, calibration system, electronic device, and storage medium for a force sensor provided according to some embodiments of the invention.

[0045] In one embodiment of the present invention, such as Figure 1 As shown, the back pressure control system 100 of the winding machine includes a friction roller 110, a yarn bobbin 120, a rocker arm 130, a slider 140, a screw motor 150, an angle sensor 161, and a force sensor 162. The friction roller 110 is rotatably connected to the first fulcrum 171, and the friction roller 110 can rotate relative to the first fulcrum 171.

[0046] Optionally, the friction roller 110 is rotatably connected to the first fulcrum 171 via the first shaft.

[0047] In one specific embodiment, a first shaft is disposed between the friction roller 110 and the first fulcrum 171. The first shaft and the friction roller 110 are relatively fixed in the circumferential direction, and the first shaft can rotate relative to the first fulcrum 171.

[0048] In another specific embodiment, a first shaft is disposed between the friction roller 110 and the first fulcrum 171, and the friction roller 110 is able to rotate relative to the first shaft.

[0049] It should be noted that the friction roller 110 is a roller roller, and the first fulcrum 171 is a roller fulcrum. The friction roller 110 is used to abut against the yarn bobbin 120 and provide a certain supporting force (i.e., support force) to the yarn bobbin 120. Figure 1 The “N” in the figure represents the supporting force of the friction roller 110 on the yarn bobbin 120.

[0050] The cradle 130 is rotatably connected to the second fulcrum 172. Optionally, the cradle 130 and the second fulcrum 172 are rotatably connected via a first pin, and the cradle 130 can rotate relative to the second fulcrum 172 about the first pin.

[0051] The screw motor 150 is used for rotatable connection with the third fulcrum 173. Optionally, the screw motor 150 and the third fulcrum 173 are rotatably connected via a second pin, and the screw motor 150 can rotate relative to the third fulcrum 173 around the second pin.

[0052] It should be noted that the second fulcrum 172 is the cradle fulcrum, and the third fulcrum 173 is the screw fulcrum.

[0053] The screw motor 150 has a rotatable screw 151. Optionally, the drive shaft of the screw motor 150 is connected to and coaxially arranged with the screw 151. The screw motor 150 is capable of driving the screw 151 to rotate circumferentially.

[0054] In one specific embodiment, the drive shaft of the screw motor 150 and the screw 151 are fixed relative to each other in the circumferential direction through a coupling, that is, while the drive shaft rotates in the circumferential direction, it can drive the screw 151 to rotate together through the coupling.

[0055] The slider 140 is rotatably mounted on the screw 151, and the screw 151 can rotate relative to the slider 140. During the rotation of the screw 151 relative to the slider 140, the relative position between the slider 140 and the screw 151 changes continuously.

[0056] In one specific embodiment, the slider 140 is provided with a through hole, and the screw 151 passes through the through hole in the slider 140, and the outer wall of the screw 151 is threadedly connected to the wall of the through hole. By rotating the screw 151, the slider 140 moves forward or backward along the length direction of the screw 151.

[0057] Optionally, a limiting end stop is provided at the end of the screw 151 away from the screw fulcrum. The limiting end stop is used to limit the range of movement of the slider 140 along the length direction of the screw 151.

[0058] Optionally, a buffer layer is provided on the limit end stop. By setting the buffer layer, a buffering effect can be achieved, effectively preventing rigid collision between the slider 140 and the limit end stop.

[0059] The cradle 130 has a first end 131 and a second end 132. The first end 131 of the cradle 130 is rotatably connected to the yarn bobbin 120, which abuts against and frictionally engages with the friction roller 110. The yarn bobbin 120 can rotate relative to the cradle 130 to wind yarn or thread. The yarn or thread is wound on the yarn bobbin 120.

[0060] Optionally, the yarn bobbin 120 and the rocker arm 130 are rotatably connected by a second shaft, which passes through the yarn bobbin 120 and the rocker arm 130, allowing the yarn bobbin 120 to rotate relative to the rocker arm 130 around the second shaft.

[0061] The second end 132 of the rocker arm 130 is rotatably connected to the slider 140. The rocker arm 130 can rotate relative to the slider 140.

[0062] It should be noted that the position where the cradle 130 is rotatably connected to the second fulcrum 172 is between the first end 131 and the second end 132.

[0063] An angle sensor 161 is disposed on the cradle 130, and the angle sensor 161 is used to obtain the position angle of the cradle 130. In other words, the angle sensor 161 is used to collect angle information or angle data to determine the position angle of the cradle 130.

[0064] A force sensor 162 is installed on the screw motor 150, and the force sensor 162 is used to obtain the actual force value of the screw motor 150. The back pressure value of the yarn bobbin 120 can be calculated based on the actual force value of the screw motor 150.

[0065] It should be noted that the actual force value here is the sampled value.

[0066] The screw motor 150 drives the screw 151 to rotate, thereby changing the relative position of the slider 140 and the screw 151, so that the yarn bobbin 120 and the rocker arm 130 rotate relative to each other.

[0067] In one embodiment of the present invention, a calibration method for a force sensor is used in a winding machine back pressure control system 100. For example... Figure 2 As shown, the calibration method for a force sensor includes the following steps:

[0068] S202, determine the initial parameters of the back pressure control system of the winding machine. The initial parameters include the radius r of the friction roller, the radius R0 of the yarn bobbin in the empty state, the weight G0 of the yarn bobbin and the cradle in the empty state, the distance L1 between the second support point and the first end, the horizontal distance L3 between the first support point and the second support point, the vertical distance L4 between the first support point and the second support point, the distance L6 between the second support point and the second end, the vertical distance L7 between the second support point and the third support point, and the horizontal distance L8 between the second support point and the third support point.

[0069] Among them, r, R0, L1, L3, L4, L6, L7, and L8 are inherent dimensional parameters of the winding machine back pressure control system. G0 is an inherent weight parameter of the winding machine back pressure control system.

[0070] It should be noted that the distance L1 between the second fulcrum and the first end refers to the distance between the position where the cradle and the second fulcrum are rotatably connected and the position where the cradle and the yarn bobbin are rotatably connected, i.e., the length of the rocker arm on the cradle. The distance L6 between the second fulcrum and the second end refers to the distance between the position where the cradle and the second fulcrum are rotatably connected and the position where the cradle and the slider are rotatably connected, i.e., the length of the rocker arm below the cradle.

[0071] r and R0 are used to determine the positional relationship between the connection position of the first fulcrum and the friction roller, and the connection position of the second fulcrum and the yarn bobbin. L1 is used to represent the positional relationship between the second fulcrum and the yarn bobbin. L3 and L4 are used to represent the positional relationship between the first fulcrum and the second fulcrum. L6 is used to represent the positional relationship between the second fulcrum and the slider. L7 and L8 are used to represent the positional relationship between the second fulcrum and the third fulcrum.

[0072] S204. When the yarn bobbin is empty and the yarn bobbin and friction roller are relatively stationary, determine the initial position angle α0 of the cradle, record the theoretical force value F0 of the screw motor as 0, and record the sampling value S0 of the force sensor.

[0073] Since the force sensor is mounted on the screw motor, it directly measures the actual force (sampled value) applied to the screw motor.

[0074] It should be noted that when the yarn bobbin is empty and relatively stationary with respect to the friction roller, the back pressure control system of the winding machine is in its initial state by default. The initial state is when the yarn bobbin is empty and naturally resting on the friction roller.

[0075] With the back pressure control system of the winding machine in its initial state, the cradle position is the initial position, and the initial position angle of the cradle is α0. With the back pressure control system of the winding machine in its initial state, the theoretical force value F0 of the screw motor is assumed to be 0, and the sampled value S0 of the force sensor is recorded.

[0076] It should be noted that the sampled value of the force sensor is the output signal value of the force sensor.

[0077] S206, control the cradle to rotate, the number of rotations is n, and the rotation angle of each rotation is Δα. i Record the current position angle of the cradle after each rotation as α. i According to G0, L1, L6, L7, L8 and α i Calculate the theoretical force F of the screw motor. i Record the sampled value S of the force sensor. i ; where α i =α i-1 +Δα i , 1≤i≤n, n≥2.

[0078] With the cradle in its initial position and the initial position angle of the cradle being α0, the screw motor slightly raises the cradle by an angle Δα1, increasing the cradle angle (the current position angle of the cradle) to α1.

[0079] The theoretical back pressure of the yarn bobbin is defined as 0. Based on G0, L1, L6, L7, L8 and α1, the theoretical force F1 of the screw motor is calculated.

[0080] With the current position angle of the cradle being α1, record the sampled value S1 of the force sensor.

[0081] The rotation angle for each rotation is Δα. i Record the current position angle of the cradle after each rotation as α. i .

[0082] Optionally, Δα i They can be the same or different. For example, Δα1 and Δα2 are different.

[0083] Optionally, Δα i The numerical range is from 1 degree to 5 degrees.

[0084] By limiting Δα i The numerical range, firstly, avoids Δα i To ensure the calibration process can sample from multiple locations, the value of Δα should not be too large, thus improving the accuracy of the calibration results; secondly, to avoid Δα... i The value is too small, ensuring that there will be a significant difference between the theoretical force value and the sampled value between multiple calibration points, which will facilitate subsequent data processing and analysis.

[0085] In one specific embodiment, Δα i The value is 1 degree.

[0086] In another specific embodiment, Δα i The value is 2 degrees.

[0087] In another specific embodiment, Δα i The value is 3 degrees.

[0088] In another specific embodiment, Δα i The value is 4 degrees.

[0089] In another specific embodiment, Δα i The value is 5 degrees.

[0090] Based on the second calculation formula, according to G0, L1, L6, L7, L8 and α i Calculate the theoretical force F of the screw motor. i .

[0091] The second calculation formula is:

[0092]

[0093] Among them, H 1i =L1×cos α i ,

[0094] θ = arctan(L7 / L8).

[0095] S208, using the theoretical force value as the abscissa and the sampled value as the ordinate, determine n+1 calibration points (0, S0), (F) in the spatial coordinate system. i S i ), (F n S n Alternatively, using sampled values ​​as the x-axis and theoretical force values ​​as the y-axis, determine n+1 calibration points (S0, 0), (S...) in the spatial coordinate system. i F i ), (S n F n ); linearity is evaluated at n+1 calibration points to determine their usability; where F n The theoretical force value of the screw motor when i = n; S n The sampled value of the force sensor when i = n.

[0096] The purpose of this step is to determine the coordinates of the calibration points so that the data can be analyzed in a combination of numerical and graphical methods.

[0097] By performing linearity analysis on the n+1 calibration points, the calibration results of the force sensor are evaluated. For calibration results with poor linearity, the calibration error is considered to be too large, and the calibration is then performed again following the steps described above for obtaining n+1 calibration points.

[0098] S210: If calibration points are available, determine the linear relationship between the theoretical force value and the sampled value, and complete the calibration of the force sensor; if calibration points are unavailable, acquire n+1 new calibration points and evaluate the linearity again.

[0099] By performing linearity analysis on the n+1 calibration points, the fitted line is used as the calibration result if the calibration points are available. If the calibration points are unavailable, the aforementioned steps are repeated to obtain new calibration points until they become available.

[0100] The present invention aims to provide a calibration method for force sensors, which can complete the calibration of force sensors without the aid of auxiliary tools. The calibration process is simple, quick, and highly accurate, which helps to reduce labor costs.

[0101] Furthermore, this method (calibration method for force sensors) adds several calibration points to the previous two-point calibration method. By continuously moving the cradle during the new calibration process, random disturbances in the mechanical state during the calibration process can be detected, and quantitative evaluation basis can be provided for the calibration results. Thus, the calibration results can be reasonably evaluated, calibration errors can be effectively identified, calibration accuracy can be significantly improved, and the overall operating performance of the mechanism can be greatly improved.

[0102] It should be noted that if the calibration error is considered too large (or the calibration points are unavailable), the calibration should be performed again following the steps described above to obtain n+1 calibration points. This method facilitates a "self-check" function, thereby ensuring the accuracy of the calibration results.

[0103] In some embodiments, optionally, such as Figure 3 As shown, linearity is evaluated at n+1 calibration points to determine their usability, including:

[0104] S2082, based on the least squares method and / or the endpoint connection method, performs linearity evaluation on n+1 calibration points to determine whether the calibration points are available.

[0105] Based on the least squares method, n+1 calibration points (0, S0), (F) are used. i S i )……(F n S n A line fitting was performed, and the equation of the fitted line was calculated as y = kx + b. Here, x is the theoretical force value F. i y is the sampled value Si , where k is the slope and b is the intercept. The sum of squares of the deviations from each calibration point to this line is minimized.

[0106] Alternatively, based on the least squares method for n+1 calibration points (S0, 0), (S i F i )……(S n F n A line fitting operation is performed, and the equation of the fitted line is calculated as y = kx + b. Where x is the sampled value S. i y is the theoretical force value F i , where k is the slope and b is the intercept. The sum of squares of the deviations from each calibration point to this line is minimized.

[0107] It should be noted that F i 0, F1...F n Any one of them; S i S0, S1...S n Any one of them.

[0108] Using the endpoint connection method, the first calibration point (0, S0) and the last calibration point (F) are connected. n S n Connect the endpoints to determine the reference straight line.

[0109] Alternatively, the endpoint connection method can be used to connect the first calibration point (S0, 0) and the last calibration point (S... n F n The endpoints are connected to determine the reference straight line.

[0110] If the linearity is deemed good, the fitted straight line is used as the calibration curve to complete the calibration. If the linearity is deemed poor, the steps of obtaining calibration points and evaluating the fit must be repeated until the linearity meets the requirements. This method facilitates a "self-checking" function, thereby ensuring the accuracy of the calibration results.

[0111] In some embodiments, optionally, such as Figure 4 As shown, S2082 (based on the least squares method and / or endpoint connection method, performs linearity evaluation on n+1 calibration points to determine whether the calibration points are usable) includes:

[0112] S2083, based on n+1 calibration points and the least squares method, determines the fitted line, minimizing the sum of the squared perpendicular distances from the n+1 calibration points to the fitted line.

[0113] Based on the least squares method, n+1 calibration points (0, S0), (F1, S1)...(F... n S nA line fitting was performed, and the equation of the fitted line was calculated as y = kx + b. Here, x is the theoretical force value F. i y is the sampled value S i , where k is the slope and b is the intercept.

[0114] Alternatively, based on the least squares method for n+1 calibration points (S0, 0), (S i F i )……(S n F n A line fitting operation is performed, and the equation of the fitted line is calculated as y = kx + b. Where x is the sampled value S. i y is the theoretical force value F i , where k is the slope and b is the intercept. The sum of squares of the deviations from each calibration point to this line is minimized.

[0115] S2084, based on n+1 calibration points and the fitted straight line, calculate the correlation coefficient γ.

[0116] The correlation coefficient γ ranges from [-1, 1]. The closer the absolute value of γ is to 1, the stronger the linear correlation.

[0117] S2085, if the absolute value of the correlation coefficient γ is greater than or equal to the preset threshold, the calibration point is determined to be available.

[0118] If the absolute value of the correlation coefficient γ is greater than or equal to the preset threshold, the linearity is determined to be good. The fitted straight line is then used as the calibration curve to complete the calibration of the force sensor.

[0119] Employing the least squares method helps optimize the overall fit of all calibration points and effectively suppresses the influence of random noise on the calibration results. Furthermore, comparing the absolute value of the correlation coefficient γ with a preset threshold helps improve the accuracy of the calibration results.

[0120] S2086, if the absolute value of the correlation coefficient γ is less than the preset threshold, the calibration point is determined to be unavailable.

[0121] If the absolute value of the correlation coefficient γ is less than a preset threshold, the linearity is deemed poor, and the steps of obtaining calibration points and evaluating the fit must be repeated until the linearity meets the requirements. This method facilitates a "self-checking" function, thereby ensuring the accuracy of the calibration results.

[0122] Optionally, the preset threshold is 0.75 to 0.95.

[0123] In one specific embodiment, the preset threshold is 0.75.

[0124] In one specific embodiment, the preset threshold is 0.8.

[0125] In one specific embodiment, the preset threshold is 0.85.

[0126] In one specific embodiment, the preset threshold is 0.9.

[0127] In one specific embodiment, the preset threshold is 0.95.

[0128] In some embodiments, optionally, γ, F i , S i as well as The following calculation formula must be satisfied:

[0129]

[0130] Among them, F i It can be any one of multiple theoretical force values; S is the average of multiple theoretical force values. i For any one of the multiple sample values, It is the average of multiple sampled values.

[0131] Comparing the absolute value of the correlation coefficient γ with a preset threshold can help improve the accuracy of the calibration results.

[0132] In some embodiments, α i Less than 90 degrees.

[0133] By limiting α i The range of values ​​has two main benefits. First, it prevents the cradle from interfering with the movement of other components or devices, thus improving the safety performance of the system. Second, it ensures that the force sensor collects sampling values ​​within its linear operating range, avoiding signal distortion caused by excessive angles and reducing the interference of nonlinear errors on the fitting results.

[0134] In some embodiments, the initial position angle α0 of the cradle can be obtained by an angle sensor, or the initial position angle α0 of the cradle can be calculated based on r, R0, L1, L3 and L4.

[0135] The direct measurement and parameter calculation of the angle sensor complement each other, avoiding calibration interruptions caused by the failure of a single method (such as α0 can still be obtained by calculation when the sensor is damaged), giving the system redundancy and fault tolerance, and adapting to complex industrial environments.

[0136] Optionally, the initial position angle α0 of the cradle is calculated based on the third calculation formula, according to r, R0, L1, L3 and L4.

[0137] The third calculation formula is:

[0138] α0 = β1 + β2.

[0139] Where β1 = arctan(L4 / L3),

[0140]

[0141] In one embodiment of the invention, a calibration system 300 for a force sensor is used in a winding machine back pressure control system 100. For example... Figure 5 As shown, the calibration system 300 for the force sensor includes an initial parameter determination unit 310, a first data processing unit 320, a control and calculation unit 340, a second data processing unit 350, and a third data processing unit 360.

[0142] The initial parameter determination unit 310 is used to determine the initial parameters of the winding machine back pressure control system 100. The initial parameters include the radius r of the friction roller 110, the radius R0 of the yarn bobbin 120 in the empty state, the weight G0 of the yarn bobbin 120 and the cradle 130 in the empty state, the distance L1 between the second fulcrum 172 and the first end 131, the horizontal distance L3 between the first fulcrum 171 and the second fulcrum 172, the vertical distance L4 between the first fulcrum 171 and the second fulcrum 172, the distance L6 between the second fulcrum 172 and the second end 132, the vertical distance L7 between the second fulcrum 172 and the third fulcrum 173, and the horizontal distance L8 between the second fulcrum 172 and the third fulcrum 173.

[0143] Among them, r, R0, L1, L3, L4, L6, L7, and L8 are inherent dimensional parameters of the winding machine back pressure control system 100. G0 is an inherent weight parameter of the winding machine back pressure control system 100.

[0144] It should be noted that the distance L1 between the second fulcrum 172 and the first end 131 refers to the distance between the position where the cradle 130 and the second fulcrum 172 are rotatably connected and the position where the cradle 130 and the yarn cylinder 120 are rotatably connected, i.e., the length of the upper rocker arm of the cradle. The distance L6 between the second fulcrum 172 and the second end 132 refers to the distance between the position where the cradle 130 and the second fulcrum 172 are rotatably connected and the position where the cradle 130 and the slider 140 are rotatably connected, i.e., the length of the lower rocker arm of the cradle.

[0145] r and R0 are used to determine the positional relationship between the connection position of the first fulcrum 171 and the friction roller 110, and the connection position of the second fulcrum 172 and the yarn bobbin 120. L1 is used to represent the positional relationship between the second fulcrum 172 and the yarn bobbin 120. L3 and L4 are used to represent the positional relationship between the first fulcrum 171 and the second fulcrum 172. L6 is used to represent the positional relationship between the second fulcrum 172 and the slider 140. L7 and L8 are used to represent the positional relationship between the second fulcrum 172 and the third fulcrum 173.

[0146] The first data processing unit 320 is used to determine the initial position angle α0 of the cradle 130 when the yarn bobbin 120 is in an empty state and the yarn bobbin 120 is relatively stationary with respect to the friction roller 110, record the theoretical force value F0 of the screw motor 150 as 0, and record the sampling value S0 of the force sensor 162.

[0147] Since the force sensor 162 is mounted on the screw motor 150, the force sensor 162 directly measures the actual force value (sampled value) of the screw motor 150.

[0148] It should be noted that when the yarn bobbin 120 is empty and the yarn bobbin 120 is relatively stationary with respect to the friction roller 110, the default back pressure control system 100 of the winding machine is in its initial state. The initial state is when the yarn bobbin 120 is empty and naturally rests on the friction roller 110.

[0149] When the back pressure control system 100 of the winding machine is in its initial state, the cradle position is the initial position, and the initial position angle of the cradle 130 is α0. When the back pressure control system 100 of the winding machine is in its initial state, the theoretical force value F0 of the screw motor 150 is assumed to be 0, and the sampled value S0 of the force sensor 162 is recorded.

[0150] It should be noted that the sampled value of the force sensor 162 is the output signal value of the force sensor 162.

[0151] The control and calculation unit 340 is used to control the cradle 130 to rotate, the number of rotations being n, and the rotation angle of each rotation being Δα. i Record the current position angle of the cradle 130 after each rotation as α. i According to G0, L1, L6, L7, L8 and α i Calculate the theoretical force F of screw motor 150. i Record the sampled value S of force sensor 162. i ; where α i =α i-1 +Δα i , 1≤i≤n, n≥2.

[0152] The rotation angle for each rotation is Δα. i Record the current position angle of the cradle 130 after each rotation as α. i .

[0153] Optionally, Δα i They can be the same or different. For example, Δα1 and Δα2 are different.

[0154] Optionally, Δα i The numerical range is from 1 degree to 5 degrees.

[0155] By limiting Δα i The numerical range, firstly, avoids Δα i To ensure the calibration process can sample multiple locations, excessively large values ​​of Δα are beneficial for improving the accuracy of the calibration results; secondly, to avoid Δα... i The value is too small, ensuring that there will be a significant difference between the theoretical force value and the sampled value between multiple calibration points, which will facilitate subsequent data processing and analysis.

[0156] In one specific embodiment, Δα i The value is 1 degree.

[0157] In another specific embodiment, Δα i The value is 2 degrees.

[0158] In another specific embodiment, Δα i The value is 3 degrees.

[0159] In another specific embodiment, Δα i The value is 4 degrees.

[0160] In another specific embodiment, Δα i The value is 5 degrees.

[0161] Based on the second calculation formula, according to G0, L1, L6, L7, L8 and α i Calculate the theoretical force F of screw motor 150. i .

[0162] The second calculation formula is:

[0163]

[0164] Among them, H 1i =L1×cosα i ,

[0165] θ = arctan(L7 / L8).

[0166] The second data processing unit 350 is used to determine n+1 calibration points (0, S0), (F) in a rectangular coordinate system, with the theoretical force value as the abscissa and the sampled value as the ordinate. i S i ), (F n S n Alternatively, using the sampled values ​​as the x-axis and the theoretical force values ​​as the y-axis, determine n+1 calibration points (S0, 0), (S...) in a rectangular coordinate system. i F i ), (S n F n ); linearity is evaluated at n+1 calibration points to determine their usability; where F n The theoretical force value of the screw motor 150 when i = n; S n The sampled value of force sensor 162 when i = n.

[0167] By performing linearity analysis on the n+1 calibration points, the calibration results of the force sensor 162 are evaluated. For calibration results with poor linearity, the calibration error is considered to be too large, and the calibration is then performed again following the steps described above for obtaining n+1 calibration points.

[0168] The third data processing unit 360 is used to determine the linear relationship between the theoretical force value and the sampled value when the calibration point is available, and to complete the calibration of the force sensor 162; when the calibration point is unavailable, it reacquires n+1 calibration points and performs linearity evaluation again.

[0169] By performing linearity analysis on the n+1 calibration points, the fitted line is used as the calibration result if the calibration points are available. If the calibration points are unavailable, the aforementioned steps are repeated to obtain new calibration points until they become available.

[0170] The present invention aims to provide a calibration system 300 for a force sensor, which can complete the calibration of the force sensor 162 without the aid of auxiliary tools. The calibration process is simple, fast and accurate, which helps to reduce labor costs.

[0171] In addition, this system (calibration system 300 for force sensors) adds several calibration points to the previous two-point calibration method. Through the continuous movement of the cradle 130 during the new calibration process, random disturbances in the mechanical state during the calibration process can be detected, and quantitative evaluation basis can be provided for the calibration results. Thus, the calibration results can be reasonably evaluated, calibration errors can be effectively identified, calibration accuracy can be significantly improved, and the overall operating performance of the mechanism can be greatly improved.

[0172] It should be noted that if the calibration error is considered too large (or the calibration points are unavailable), the calibration should be performed again following the steps described above to obtain n+1 calibration points. This method facilitates a "self-check" function, thereby ensuring the accuracy of the calibration results.

[0173] In one embodiment of the present invention, such as Figure 6 As shown, the electronic device 400 includes a memory 410 and a processor 420. The memory 410 stores programs or instructions that can be executed on the processor 420. When the processor 420 executes the programs or instructions, it implements the steps of the force sensor calibration method in any of the above embodiments. The electronic device 400 has the beneficial effects of any of the above embodiments, which will not be elaborated further here.

[0174] In one embodiment of the present invention, the readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the force sensor calibration method in any of the above-described technical solutions. The readable storage medium possesses the beneficial effects of any of the above embodiments, which will not be elaborated further here.

[0175] In this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0176] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," 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 unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0177] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0178] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A calibration method for a force sensor, characterized in that, For use in the back pressure control system of a winding machine, the back pressure control system of the winding machine includes a friction roller, a yarn bobbin, a rocker arm, a slider, a screw motor, an angle sensor and a force sensor; The friction roller is rotatably connected to the first fulcrum, the rocker arm is rotatably connected to the second fulcrum, and the screw motor is rotatably connected to the third fulcrum. The screw motor has a rotatable screw, and the slider is rotatably mounted on the screw; the rocker arm has a first end and a second end opposite to each other, the first end is rotatably connected to the yarn bobbin, the yarn bobbin is in frictional engagement with the friction roller, and the second end is rotatably connected to the slider; The angle sensor is disposed on the rocker arm and is used to obtain the position angle of the rocker arm; the force sensor is disposed on the screw motor and is used to obtain the actual force value of the screw motor. The screw motor drives the screw to rotate, thereby changing the relative position of the slider and the screw, so that the yarn bobbin and the rocker arm rotate relative to each other; The calibration method includes: The initial parameters of the back pressure control system of the winding machine are determined. The initial parameters include the radius r of the friction roller, the radius R0 of the yarn bobbin in the empty state, the weight G0 of the yarn bobbin and the cradle in the empty state, the distance L1 between the second fulcrum and the first end, the horizontal distance L3 between the first fulcrum and the second fulcrum, the vertical distance L4 between the first fulcrum and the second fulcrum, the distance L6 between the second fulcrum and the second end, the vertical distance L7 between the second fulcrum and the third fulcrum, and the horizontal distance L8 between the second fulcrum and the third fulcrum. When the yarn bobbin is empty and the yarn bobbin is relatively stationary with respect to the friction roller, determine the initial position angle α0 of the rocker arm, record the theoretical force value F0 of the screw motor as 0, and record the sampling value S0 of the force sensor. The cradle is controlled to rotate, the number of rotations is n, and the rotation angle of each rotation is Δα. i The current position angle of the cradle after each rotation is recorded as α. i According to G0, L1, L6, L7, L8 and α i Calculate the theoretical force value F of the screw motor. i Record the sampled value S of the force sensor. i ; where α i =α i-1 +Δα i , 1≤i≤n, n≥2; Using the theoretical force value as the abscissa and the sampled value as the ordinate, determine n+1 calibration points (0, S0), (F) in the spatial coordinate system. i S i ), (F n S n Alternatively, using sampled values ​​as the x-axis and theoretical force values ​​as the y-axis, determine n+1 calibration points (S0, 0), (S...) in the spatial coordinate system. i F i ), (S n F n ); perform linearity evaluation on the n+1 calibration points to determine whether the calibration points are usable; where, F n The theoretical force value of the screw motor when i=n; S n When i=n, ​​the sampled value of the force sensor; If the calibration point is available, determine the linear relationship between the theoretical force value and the sampled value, and complete the calibration of the force sensor; if the calibration point is unavailable, reacquire n+1 calibration points and evaluate the linearity again. α i Less than 90 degrees; The initial position angle α0 of the cradle is obtained by the angle sensor, or the initial position angle α0 of the cradle is calculated based on r, R0, L1, L3 and L4 according to the third calculation formula. The third calculation formula is: ； in, , ; 。 2. The calibration method for the force sensor according to claim 1, characterized in that, The step of evaluating the linearity of the n+1 calibration points to determine whether the calibration points are usable includes: Based on the least squares method and / or the endpoint connection method, the linearity of the n+1 calibration points is evaluated to determine whether the calibration points are usable.

3. The calibration method for the force sensor according to claim 2, characterized in that, The linearity evaluation of the n+1 calibration points based on the least squares method and / or endpoint connection method to determine whether the calibration points are usable includes: Based on the n+1 calibration points and the least squares method, a fitted line is determined, wherein the sum of the squared perpendicular distances from the n+1 calibration points to the fitted line is minimized; Based on the n+1 calibration points and the fitted line, the correlation coefficient γ is calculated. If the absolute value of the correlation coefficient γ is greater than or equal to a preset threshold, the calibration point is determined to be usable.

4. The calibration method for the force sensor according to claim 3, characterized in that, The method of evaluating the linearity of the n+1 calibration points based on the least squares method and / or the endpoint connection method to determine whether the calibration points are usable also includes: If the absolute value of the correlation coefficient γ is less than the preset threshold, the calibration point is determined to be unusable.

5. The calibration method for the force sensor according to claim 3, characterized in that, ； Among them, F i It can be any one of multiple theoretical force values; S is the average of multiple theoretical force values. i For any one of the multiple sample values, It is the average of multiple sampled values.

6. A calibration system for a force sensor, characterized in that, include: An initial parameter determination unit (310) is used to determine the initial parameters of the winding machine back pressure control system (100). The initial parameters include the radius r of the friction roller (110), the radius R0 of the yarn bobbin (120) in the empty state, the weight G0 of the yarn bobbin (120) and the cradle (130) in the empty state, the distance L1 between the second fulcrum (172) and the first end (131), the horizontal distance L3 between the first fulcrum (171) and the second fulcrum (172), the vertical distance L4 between the first fulcrum (171) and the second fulcrum (172), the distance L6 between the second fulcrum (172) and the second end (132), the vertical distance L7 between the second fulcrum (172) and the third fulcrum (173), and the horizontal distance L8 between the second fulcrum (172) and the third fulcrum (173). The first data processing unit (320) is used to determine the initial position angle α0 of the cradle (130) when the yarn bobbin (120) is in an empty state and the yarn bobbin (120) is relatively stationary with respect to the friction roller (110), record the theoretical force value F0 of the screw motor (150) as 0, and record the sampling value S0 of the force sensor (162). The control and calculation unit (340) is used to control the cradle (130) to rotate, the number of rotations being n, and the rotation angle of each rotation being Δα. i The current position angle of the cradle (130) after each rotation is recorded as α. i According to G0, L1, L6, L7, L8 and α i Calculate the theoretical force F of the screw motor (150). i Record the sampled value S of the force sensor (162). i ; where α i =α i-1 +Δα i , 1≤i≤n, n≥2; The second data processing unit (350) is used to determine n+1 calibration points (0, S0), (F) in the spatial coordinate system, with the theoretical force value as the abscissa and the sampled value as the ordinate. i S i ), (F n S n Alternatively, using sampled values ​​as the x-axis and theoretical force values ​​as the y-axis, determine n+1 calibration points (S0, 0), (S...) in the spatial coordinate system. i F i ), (S n F n ); perform linearity evaluation on the n+1 calibration points to determine whether the calibration points are usable; where, F n The theoretical force value of the screw motor when i=n; S n When i=n, ​​the sampled value of the force sensor; The third data processing unit (360) is used to determine the linear relationship between the theoretical force value and the sampled value when the calibration point is available, and to complete the calibration of the force sensor (162); when the calibration point is unavailable, it reacquires n+1 calibration points and performs linearity evaluation again. α i Less than 90 degrees; The initial position angle α0 of the cradle (130) is obtained by the angle sensor (161), or the initial position angle α0 of the cradle (130) is calculated based on r, R0, L1, L3 and L4 according to the third calculation formula. The third calculation formula is: ； in, , ; 。 7. An electronic device, characterized in that, include: A memory (410) and a processor (420), wherein the memory (410) stores a program or instructions executable on the processor (420), and the processor (420) executes the program or instructions to implement the steps of the calibration method for the force sensor as described in any one of claims 1 to 5.

8. A readable storage medium, characterized in that, The readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the calibration method for the force sensor as described in any one of claims 1 to 5.

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