Compensation Method for Full-Circle Tilt Weighing Error of Electronic Scale with Double-Hole Cantilever Beam Sensor

Abstract

The present invention discloses a compensation method for the full - circumference tilt weighing error of a double - hole cantilever beam sensor electronic scale. An inclination angle detection device is added inside the double - hole cantilever beam sensor electronic scale to obtain the real - time inclination angle; under two inclination directions, the characteristic curves of the inclination angle and its weighing error when weighing the same weight, and the characteristic curves of different weights and their weighing errors under the same inclination angle are obtained; according to the characteristic curves, the estimated values of the parameter group of the tilt weighing error calculation model are calculated by fitting; the estimated values of the parameter group are substituted into the model to obtain the tilt weighing error calculation models under two inclination directions; they are integrated to obtain the total model, and the error value of the current tilt attitude is calculated in real time through the total model, and the indication value of the electronic scale is compensated to obtain the correct weight indication value. The present invention can realize the correction and compensation of the full - circumference tilt weighing error of the double - hole cantilever beam electronic scale, improve the measurement accuracy of the double - hole cantilever beam electronic scale, and has high method efficiency and high accuracy.

Description

Technical Field

[0001] The present invention relates to a method for compensating the weighing error of a full - circumference inclined electronic scale, and in particular to a method for compensating the weighing error of a full - circumference inclined electronic scale with a special double - hole cantilever beam sensor. Background Art

[0002] Weighing with an electronic scale is a common method for modern mass measurement. It has the characteristics of low latency, large range, simple operation, convenient use, and easy digital control, and is widely used in various fields such as financial trade, production manufacturing, industrial processing, and scientific research. Therefore, the accuracy of the electronic scale is particularly important.

[0003] At the present stage in the market, the electronic scale with a double - hole cantilever beam sensor is the most used and widely applied electronic scale. The horizontality of the installation position during the use of the double - hole cantilever beam type electronic scale is a prerequisite for ensuring its accuracy. However, in actual applications, the installed plane is often non - horizontal, such as the electronic scale on a vehicle, the electronic scale on a conveyor belt, etc. This reduces the accuracy of the electronic scale, resulting in inaccurate weighing or even a large error.

[0004] Regarding the error compensation for the inclination of the double - hole cantilever beam type electronic scale, the research at home and abroad is not sufficient at the present stage, and there are few relevant literatures. And generally, only the inclination error compensation in a single direction is carried out, such as the paper "Research on the Angle Automatic Compensation Method of the Weighing System" by Jin Jianjiao (published in "Weighing Apparatus" on P18 - 21 in February 2008) and the paper "Discussion on the Inclination Test Error of the Electronic Scale" by Guo Jing (published in "Weighing Apparatus" on P35 - 38 in December 2013). And there is no specific compensation algorithm modeling analysis, with low practical value. Summary of the Invention

[0005] In order to avoid and solve the above - mentioned technical problems, the present invention proposes a method for compensating the weighing error of a full - circumference inclined double - hole cantilever beam electronic scale.

[0006] As Figure 4 shown, the technical solution of the present invention is as follows:

[0007] 1) Add an inclination angle detection device in the original system of the double - hole cantilever beam sensor electronic scale to obtain the real - time inclination attitude parameters of the double - hole cantilever beam sensor electronic scale. The inclination angle detection device is installed in the double - hole cantilever beam sensor electronic scale, and the inclination angle detection device outputs the included angle between its own plane and the horizontal as inclination angle data and sends it to the data processor;

[0008] 2) Obtain the characteristic curves under the following two cases respectively:

[0009] The first method: within the range of 1% to 100% of the weighing capacity of the dual-hole cantilever beam sensor electronic scale, under two different orthogonal tilting directions, the two orthogonal tilting directions are divided into tilting around the axis perpendicular to the holes of the dual-hole cantilever beam and tilting around the axis of the holes of the dual-hole cantilever beam, respectively, as shown in Figure 3 and Figure 4 shown. Tilt the dual-hole cantilever beam sensor electronic scale multiple times and simultaneously measure the tilting angle through the tilting angle detection device, denoted as:

[0010]

[0011] where:

[0012] — The tilting angle corresponding to the tilting direction around the axis perpendicular to the holes of the dual-hole cantilever beam;

[0013] — The tilting angle corresponding to the tilting direction around the axis of the holes of the dual-hole cantilever beam;

[0014] — The tilting weighing error in the tilting direction around the axis perpendicular to the holes of the dual-hole cantilever beam;

[0015] — The tilting weighing error in the tilting direction around the axis of the holes of the dual-hole cantilever beam;

[0016] n — The percentage of the weighing weight occupying the maximum range;

[0017] Furthermore, obtain the characteristic curve between the tilting angle of the electronic scale and the weighing error under each fixed weighing weight;

[0018] The second method: within the range of -15° to 15° of the tilting angle of the dual-hole cantilever beam sensor electronic scale, under two different orthogonal tilting directions, the two orthogonal tilting directions are divided into tilting around the axis perpendicular to the holes of the dual-hole cantilever beam and tilting around the axis of the holes of the dual-hole cantilever beam. Tilt the dual-hole cantilever beam sensor electronic scale multiple times and simultaneously measure the tilting angle through the tilting angle detection device, denoted as:

[0019] U x [m], U y [m], E ux [m], E uy [m], m = -15 to 15

[0020] where:

[0021] U x [m] — The indication value of the electronic scale in the tilting direction around the axis perpendicular to the holes of the dual-hole cantilever beam;

[0022] U y[m] — The indicated value of the electronic scale when the inclination direction is inclined around the axis of the double-hole cantilever beam hole;

[0023] E ux [m] — The inclination weighing error when the inclination direction is inclined around the direction perpendicular to the axis of the double-hole cantilever beam hole;

[0024] E uy [m] — The inclination weighing error when the inclination direction is inclined around the axis of the double-hole cantilever beam hole;

[0025] m — The degree of the inclination angle measured by the inclination angle detection device;

[0026] Measure the characteristic curves of the indicated values and the corresponding weighing errors of the electronic scale when weighing different weights at each fixed inclination direction and its inclination angle;

[0027] The said inclination weighing error is obtained from the difference between the object with a known accurate weight and the indicated value of the weight of the double-hole cantilever beam sensor electronic scale.

[0028] 3) Establish the following inclination weighing error calculation model according to the force relationship of the heavy object on the inclined plane. According to the data of each characteristic curve obtained in step 2), use the method of fitting the curve to calculate the estimated values of the parameter group of the inclination weighing error calculation model

[0029]

[0030]

[0031]

[0032] In the formula: E0 is the fitted inclination weighing error; K is the conversion coefficient for converting the voltage value into the weighing weight; U is the voltage value output by the weighing sensor; is the inclination angle measured by the inclination angle detection device; is the additional inclination angle of the scale surface due to the weighing weight of the electronic scale; is the inclination angle The compensation amount of the weighing weight under; a, b, c, d, k0, k1, k2 are the first, second, third, fourth, fifth, sixth, and seventh undetermined parameters of the model, which form the parameter group; where K, U, and are known quantities.

[0033] 4) Substitute the estimated values of the parameter group calculated in step 3) into the inclination weighing error calculation model to obtain the inclination weighing error calculation model of the actual double-hole cantilever beam sensor electronic scale in the two inclination directions described in step 2):

[0034]

[0035]

[0036] Among them, the above two formulas are respectively the calculation model of the tilt weighing error in the tilt direction of the hole axis of the double-hole cantilever beam of the electronic scale and the calculation model of the tilt weighing error when the electronic scale rotates around the tilt direction of the hole axis of the double-hole cantilever beam.

[0037] In the formula: E x and E y are respectively the tilt weighing errors in the tilt direction around the hole axis of the double-hole cantilever beam and in the tilt direction perpendicular to the hole axis of the double-hole cantilever beam; and are respectively the tilt angles of the electronic scale in the tilt direction around the hole axis of the double-hole cantilever beam and in the tilt direction perpendicular to the hole axis of the double-hole cantilever beam; a x , b x , c x and d x are the estimated values of the undetermined parameters in the weighing error calculation model in the tilt direction of the hole axis of the double-hole cantilever beam of the electronic scale obtained in step 3) Component in the tilt direction around the hole axis of the double-hole cantilever beam; a y , b y , c y , d y are the estimated values of the undetermined parameters in the weighing error calculation model when the electronic scale rotates around the tilt direction of the hole axis of the double-hole cantilever beam obtained in step 3) Component in the tilt direction perpendicular to the hole axis of the double-hole cantilever beam; represents the compensation amount of the weighing weight only at the tilt angle in the tilt direction around the hole axis of the double-hole cantilever beam, represents the compensation amount of the weighing weight only at the tilt angle in the tilt direction perpendicular to the hole axis of the double-hole cantilever beam, U represents the voltage value output by the weighing sensor, represents the tilt angle increased by the weighing table surface due to the weighing weight of the electronic scale;

[0038] 5) Integrate the tilt weighing error calculation models in the two tilt directions obtained in step 4) to obtain the total tilt weighing error calculation model, which is expressed as follows:

[0039]

[0040] In the formula: E is the compensation amount of the actual total tilt weighing error;

[0041] 6) The total tilt weighing error calculation model is solidified in the data processor of the electronic scale, and the voltage value U output by the double-hole cantilever beam weighing sensor in the electronic scale and the tilt angle parameters output by the tilt angle detection device in the tilt direction around the double-hole cantilever beam hole axis and around the tilt direction perpendicular to the double-hole cantilever beam hole axis are combined. The total tilt weighing error calculation model is input to obtain the error value E of the electronic scale at each tilt angle, and the electronic scale indication is compensated to obtain the correct weight indication after compensation.

[0042] The tilt angle detection device adopts an acceleration sensor, and the acceleration sensor detects at least two acceleration axes.

[0043] The double-hole cantilever beam sensor electronic scale is a table scale.

[0044] The curve fitting method includes but is not limited to the least squares method, spline curve fitting, etc.

[0045] The present invention calculates the electronic scale tilt weighing error by bringing the tilt posture parameter output by the tilt angle detection device added to the electronic scale system and the voltage value output by the electronic scale weighing sensor into the total tilt weighing error calculation model, so as to compensate for the electronic scale indication to make it close to the actual weight of the weight.

[0046] The beneficial effects of the present invention are:

[0047] The invention can realize the correction and compensation of the full-circle tilt weighing error of the double-hole cantilever beam electronic scale, improve the measurement accuracy of the double-hole cantilever beam electronic scale, and has high efficiency and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a simple block diagram of the electronic scale system after adding a tilt angle detection device;

[0049] Figure 2 It is a schematic diagram of the decomposition of gravity of a heavy object on an inclined plane;

[0050] Figure 3 It is a schematic diagram of the tilt of a double-hole cantilever beam electronic scale (including two tilt directions);

[0051] Figure 4 It is a flow chart of the present invention;

[0052] Figure 5 This is a simplified installation diagram of the tilt angle detection device;

[0053] Figure 6 It is the compensation curve in the tilt weighing error calculation model when the electronic scale is tilted around the curve perpendicular to the axis of the double-hole cantilever beam in the example. The fitting curve diagram of

[0054] Figure 7 It is the compensation curve in the tilt weighing error calculation model in the tilt direction of the electronic scale around the hole axis of the double-hole cantilever beam in the example. The fitting curve graph;

[0055] Figure 8 It is the d in the tilt weighing error calculation model in the tilt direction of the electronic scale around the hole axis of the double-hole cantilever beam in the example. y The fitting curve graph;

[0056] Table 1 shows the indication data when the tilt weighing is full load before and after implementing the present invention in the example.

[0057] In the figure: 1, weighing tabletop, 2, double-hole cantilever beam weighing sensor, 3, tilt angle detection device, 4, data processor, 5, electronic scale base. Specific implementation manner

[0058] In order to make the purpose, technical solution and advantages of the present application clearer, the following further explains the present application in combination with the accompanying drawings and embodiments. However, all descriptions are only for explanation and should not be construed as any limitation to the formation of the invention patent of the present application. In addition, any single technical feature described or implied in each embodiment mentioned in this article, or any single technical feature shown or implied in each drawing, can still be arbitrarily combined or deleted between these technical features (or their equivalents), so as to obtain more other embodiments of the invention patent of the present application that may not be directly mentioned in this article. In addition, for the sake of simplifying the drawings, the same or similar technical features may only be marked at one place in the same drawing.

[0059] The device adopted by the method of the present invention is as Figure 5 shown, including a weighing tabletop 1, a double-hole cantilever beam weighing sensor 2, a tilt angle detection device 3, a data processor 4 and an electronic scale base 5. The double-hole cantilever beam sensor electronic scale includes a weighing tabletop 1, a double-hole cantilever beam weighing sensor 2 and an electronic scale base 5. The double-hole cantilever beam weighing sensor 2 is installed between the weighing tabletop 1 and the electronic scale base 5. The weighing tabletop 1 is located above the electronic scale base 5. A tilt angle detection device 3 is installed on the top surface of one side of the electronic scale base 5. The tilt angle detection device 3 faces the weighing tabletop 1 to detect the change in the included angle between the bottom surface of the weighing tabletop 1 and the electronic scale base 5.

[0060] Normally, the bottom surface of the weighing tabletop 1 and the top surface of the electronic scale base 5 are parallel. When the double-hole cantilever beam sensor electronic scale has an error due to full-circle tilt, the tilt angle detection device 3 is set to detect the non-parallel degree between the bottom surface of the weighing tabletop 1 and the top surface of the electronic scale base 5, and perform feedback compensation.

[0061] In a specific implementation, a data processor 4 is further installed on the top surface of the electronic scale base 5. The data processor 4 is electrically connected to the tilt angle detection device 3 and is used to process the data detected by the tilt angle detection device 3.

[0062] In a specific implementation, the tilt angle detection device 3 uses an acceleration sensor. The number of acceleration axes detected by the acceleration sensor is at least two axes. The double-hole cantilever beam sensor electronic scale is a table scale.

[0063] To further understand this invention patent, the following examples are given and described in detail with the accompanying drawings as follows:

[0064] Combined with Figure 2 It can be known that a heavy object with a mass of M is on a plane with an inclination angle of as Figure 8 shown. The pressure of the heavy object on the plane is the balance force of the component force F1 of the gravity along the direction perpendicular to the plane The voltage value U output by the double-hole cantilever beam weighing sensor is positively correlated with the pressure it receives. Assuming that the output voltage of the double-hole cantilever beam weighing sensor during horizontal weighing is U0, the relationship between U and U0 is set as:

[0065] And the tilt weighing error E = K(U0 - U), where K is the coefficient for converting voltage to mass. Let be the compensation curve, then the tilt weighing error calculation model is obtained:

[0066]

[0067] According to the actual situation, a tilt angle detection device 3 is added to the double-hole cantilever beam sensor electronic scale system as Figure 5 . The specific installation position can be adjusted according to the actual situation, but it is necessary to ensure that the tilt angle detection device 3 is installed on the electronic scale base 5 and has the same level as it. The tilt angle detection device 3 contains an acceleration sensor. The number of axes of the acceleration sensor is at least two axes. The acceleration sensor can output the tilt attitude parameters of the plane where it is located to the data processor 4 of the electronic scale.

[0068] As Figure 4 shown, the implementation and effect of this method will be introduced and described below through a specific double-hole cantilever beam sensor electronic scale.

[0069] Double-hole cantilever beam sensor electronic scale: A double-hole double-hole cantilever beam table scale with a range of 30000g and a resolution of 5g. Because when the tilt angle exceeds 12°, the heavy object on the scale surface of this electronic scale will slide naturally and cannot be weighed, so the tilt angle range of the scale is set as At the same time, the tilt angle detection device 3 is installed on the scale and is in the same plane as its base as Figure 5 .

[0070] Experiments were carried out by weighing from 0 to 30000 g every 300 g. Under two tilting directions (the axis of the double-hole cantilever beam hole of the electronic scale tilts and the electronic scale tilts around the axis of the double-hole cantilever beam hole), the characteristic curves of the tilting angle of the electronic scale and the weighing error were measured and recorded as:

[0071]

[0072] In specific implementation, n takes the weighing weight of 300n grams.

[0073] By measuring within the tilting angle range of -12° to 12°, under two tilting directions (the axis of the double-hole cantilever beam hole of the electronic scale tilts and the electronic scale tilts around the axis of the double-hole cantilever beam hole), the characteristic curves of the indication value of the electronic scale weighing different weights and its weighing error were measured and recorded as:

[0074] U x [m], U y [m], E ux [m], E uy [m], m = -12 to 12

[0075] According to the data of the characteristic curves, the estimated values of the parameter group of the tilting weighing error calculation model were calculated by using the method of fitting curves. The tilting weighing error calculation model is:

[0076]

[0077]

[0078]

[0079] Substitute the calculated estimated values of the parameter group for the undetermined parameter group in the tilting weighing error calculation model to obtain the tilting weighing error calculation model of the double-hole cantilever beam sensor electronic scale under two tilting directions:

[0080]

[0081]

[0082] Obtain the compensation curve in the tilting weighing error calculation model in the tilting direction of the axis of the double-hole cantilever beam hole of the electronic scale. Such as Figure 6 .

[0083] The compensation curve in the tilting weighing error calculation model in the tilting direction of the electronic scale around the axis of the double-hole cantilever beam hole. Such as Figure 7 , d y = c y·(k0.v 2 +k1.v + k2) as Figure 8 。

[0084] Integrate the obtained tilt weighing error calculation models in two tilt directions to obtain the total tilt weighing error calculation model:

[0085]

[0086] Finally, solidify the total tilt weighing error calculation model formula in the data processor 4 of the electronic scale, and combine the voltage value U output by the double-hole cantilever beam weighing sensor 2 in the electronic scale and the attitude parameters output by the tilt angle detection device 3 to obtain the error value E of the electronic scale in each tilted attitude, and compensate the indicated value of the electronic scale to obtain the correct weight indicated value. The indicated values of the full-load output before and after compensation are shown in Table 1.

[0087] The above-described embodiments only represent one implementation manner of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A compensation method for the full - circumference tilt weighing error of a double - hole cantilever beam sensor electronic scale, characterized in that, The method comprises the following steps: 1) Add an inclination angle detection device (3) in the double-hole cantilever beam sensor electronic scale to obtain the real-time inclination attitude parameters of the double-hole cantilever beam sensor electronic scale. The inclination angle detection device (3) is installed in the double-hole cantilever beam sensor electronic scale, and the inclination angle detection device (3) outputs the included angle between its own plane and the horizontal as inclination angle data; 2) Obtain characteristic curves under the following two situations respectively: The first: within the range of 1% to 100% of the weighing range of the double-hole cantilever beam sensor electronic scale, under two different orthogonal inclination directions. The two orthogonal inclination directions are respectively inclined around the axis perpendicular to the double-hole axis of the cantilever beam and inclined around the double-hole axis of the cantilever beam. Tilt the double-hole cantilever beam sensor electronic scale multiple times and simultaneously measure the inclination angle through the inclination angle detection device (3), denoted as: Where: — the tilt angle corresponding to the tilt direction being tilted around the axis perpendicular to the holes of the double-hole cantilever beam; — the tilt angle corresponding to the tilt direction being tilted about the axis of the double-hole cantilever beam hole; — the tilting weighing error when the tilting direction is tilting around the axis perpendicular to the holes of the double-hole cantilever beam; —tilt weighing error when the tilt direction is tilting around the axis of the double-hole cantilever beam hole; n—the percentage of the weighing weight occupying the maximum range; Furthermore, plot the characteristic curve between the inclination angle of the electronic scale and the weighing error; The second: within the range of -15° to 15° of the inclination angle of the double-hole cantilever beam sensor electronic scale, under two different orthogonal inclination directions. The two orthogonal inclination directions are respectively inclined around the axis perpendicular to the double-hole axis of the cantilever beam and inclined around the double-hole axis of the cantilever beam. Tilt the double-hole cantilever beam sensor electronic scale multiple times and simultaneously measure the inclination angle through the inclination angle detection device (3), denoted as: U x [m], U y [m], E ux [m], E uy [m], m = -15 to 15 Where: U x [m]— the indicated value of the electronic scale when the inclination direction is inclined around the axis perpendicular to the holes of the double-hole cantilever beam; U y [m] — the indicated value of the electronic scale when the inclination direction is the inclination around the axis of the double-hole cantilever beam hole; E ux [m] — the tilt weighing error when the tilt direction is tilted around the axis perpendicular to the holes of the double-hole cantilever beam; E uy [m] — the tilt weighing error when the tilt direction is tilted around the axis of the double-hole cantilever beam hole; m—the degree of the inclination angle measured by the inclination angle detection device (3); Measure the characteristic curve of the indication value of the electronic scale weighing different weights and the corresponding weighing error; 3) Establish the following inclined weighing error calculation model based on the force relationship of the heavy object on the inclined plane. According to the data of the characteristic curve obtained in step 2), use the method of fitting the curve to calculate the estimated value of the parameter group of the inclined weighing error calculation model Where: E0 is the tilt weighing error; K is the conversion coefficient for converting the voltage value into the weighing weight; U is the voltage value output by the weighing sensor; is the tilt angle measured by the tilt angle detection device (3); is the additional tilt angle of the weighing platform (1) due to the weighing weight of the electronic scale; is the tilt angle is the compensation amount of the weighing weight under the tilt angle; a, b, c, d, k0, k1, k2 are the first, second, third, fourth, fifth, sixth, and seventh undetermined parameters of the model, which form a parameter group; 4) Substitute the estimated values of the parameter groups calculated in step 3) into the tilt weighing error calculation model to obtain the tilt weighing error calculation models of the actual dual-hole cantilever beam sensor electronic scale in the two orthogonal tilt directions described in step 2): Where: E x and E y are the tilt weighing errors in the tilt direction around the hole axis of the double-hole cantilever beam and in the tilt direction perpendicular to the hole axis of the double-hole cantilever beam, respectively; and are the tilt angles of the electronic scale in the tilt direction around the hole axis of the double-hole cantilever beam and in the tilt direction perpendicular to the hole axis of the double-hole cantilever beam, respectively; and are the estimated values of the undetermined parameters in the component in the tilt direction around the hole axis of the double-hole cantilever beam; are the estimated values of the undetermined parameters in the component in the tilt direction perpendicular to the hole axis of the double-hole cantilever beam; represents the compensation amount of the weighing weight only at the tilt angle in the tilt direction around the hole axis of the double-hole cantilever beam, represents the compensation amount of the weighing weight only at the tilt angle in the tilt direction perpendicular to the hole axis of the double-hole cantilever beam, and U represents the voltage value output by the load cell, represents the increased tilt angle of the weighing platform (1) due to the weighing weight of the electronic scale; 5) Integrate the inclination weighing error calculation models of the two inclination directions obtained in step 4) to obtain the total inclination weighing error calculation model, expressed as follows: In the formula: E is the compensation amount of the actual total inclination weighing error; 6) Combine the voltage value U output by the double-hole cantilever beam weighing sensor (2) inside the electronic scale and the tilt angle parameters output by the tilt angle detection device (3) in the tilt directions of tilting around the hole axis of the double-hole cantilever beam and tilting around the axis perpendicular to the hole axis of the double-hole cantilever beam. Input into the total tilt weighing error calculation model to obtain the error value E of the electronic scale in various tilt angle postures.

2. A compensation method for the full - circumference tilt weighing error of a dual - hole cantilever beam sensor electronic scale according to claim 1, characterized in that: The inclination angle detection device (3) adopts an acceleration sensor, and the number of acceleration axes detected by the acceleration sensor is at least two axes.

3. A compensation method for the full - circumference tilt weighing error of a double - hole cantilever beam sensor electronic scale according to claim 1, characterized in that: The double-hole cantilever beam sensor electronic scale is a table scale.

4. A compensation method for the full - circumference tilt weighing error of a double - hole cantilever beam sensor electronic scale according to claim 1, characterized in that: The method for fitting the curve includes the least squares method or spline curve fitting.

Images