Method for calibrating torque in ultra-wide range section

Abstract

The invention relates to a torque calibration method for an ultra-large range section, which is used for calibrating the torque when the torque range section required to be calibrated exceeds the maximum range range which can be calibrated by a traditional torque measurement standard device, and adopts a linear fitting extrapolation method. The method comprises the following steps of: firstly, separately calculating a torque standard value part and a torque measurement deviation part; and the calculation results of the two parts are adjusted through different extrapolation coefficients, so that a linear extrapolation calculation value after the range is expanded can be obtained. According to the torque calibration method for the ultra-wide range section, reasonable extrapolation estimation can be carried out on the torque value of the ultra-wide range when the torque value in the small range range is calibrated. The method can be widely applied to ultra-large torque measurement calibration scenes such as high-rotating-speed engines or wind turbines and the like, so that accurate measurement and traceability of ultra-large torque values in the industrial field are guaranteed.

Description

Technical Field

[0001] The invention relates to the field of torque measurement, and in particular to a method for calibrating torque in an ultra-large range segment. Background Art

[0002] The actual need to measure ultra-large torque values ​​in scenarios such as high-speed engines and wind turbines faces a technical challenge: how to accurately measure and calibrate ultra-large torque values ​​that exceed the range of existing torque measurement standard devices. This problem is particularly prominent in the industrial and energy fields, because the equipment in these scenarios often needs to operate stably in a high torque environment, and has extremely high requirements for the measurement accuracy and reliability of ultra-large torque values. Summary of the invention

[0003] The technical problem solved by the present invention is to accurately measure and calibrate ultra-large torque values ​​that exceed the measuring range of existing torque measurement standard devices. In order to solve the problem that the existing torque measurement standard devices are limited by their design principles and mechanical structures and cannot directly measure, calibrate and calibrate ultra-large torque values ​​that exceed the measuring range, a method for calibrating ultra-large range torque is provided. A new linear extrapolation method is used to reasonably extrapolate and estimate the ultra-large range torque value when calibrating the torque value within a small range. This method can be widely used in ultra-large torque measurement and calibration scenarios such as high-speed engines or wind turbines to ensure accurate measurement and traceability of ultra-large torque values ​​in the industrial field.

[0004] To achieve the above-mentioned purpose, the technical solution of the present invention is: a super-large range torque calibration method, which is used for torque calibration when the torque range to be calibrated exceeds the maximum range that can be calibrated by a traditional torque measurement standard device, and adopts a linear fitting extrapolation method. First, the torque standard value part and the torque measurement deviation part are calculated separately, and then the calculation results of the two parts are adjusted by different extrapolation coefficients, so as to obtain the linear extrapolation calculation value after the range is expanded.

[0005] Furthermore, the specific calculation method of the linear fitting extrapolation method is as follows:

[0006]

[0007] In formula (1): y i ex —Extrapolation result of the i-th torque value;

[0008] —The standard value corresponding to the i-th torque measurement value;

[0009] m l —Linear extrapolation coefficient of extrapolation range and measurement range;

[0010] k l—Linear extrapolation coefficient of the deviation part of torque measurement;

[0011] Δx i —The error offset ratio of the i-th torque value satisfies the following formula:

[0012]

[0013] In formula (2): x i — the i-th torque measurement value;

[0014] —The standard value corresponding to the i-th torque measurement value;

[0015] From formula (1), we can see that the key to the linear fitting extrapolation method lies in the extrapolation coefficient m l and k l The selection of l It can be directly determined by the magnification between different ranges, but k l It is determined by the amplitude parameters of the partial segment and the ratio of the full-scale to the partial segment amplitudes; usually, this amplitude ratio is unknown but is estimated by measuring different partial segments.

[0016] Furthermore, according to the linear fitting extrapolation method, by obtaining multiple amplitudes and linearly extrapolating the amplitude of the full range segment, and then with the help of the extrapolation estimation curve, k can be roughly obtained. l The value of extrapolation coefficient m is determined l and k l Afterwards, the extrapolated estimate can be finally calculated.

[0017] Furthermore, the torque is measured using an ultra-large torque sensor installed on a torque standard device to obtain torque measurement curves in different ranges.

[0018] Furthermore, the calculation results of the two parts were adjusted by different extrapolation coefficients to obtain a comparison curve of the linear fitting error ratio of torque measurement after different measuring ranges and linear scaling extrapolation.

[0019] The beneficial effects of the present invention are:

[0020] 1. It breaks through the technical bottleneck that traditional torque measurement standard devices cannot directly calibrate ultra-large torque values ​​beyond the measuring range;

[0021] 2. The formula calculation is simple and fast, and easy to operate and implement;

[0022] 3. High calibration accuracy. During the calibration process of the 2.5MN·m ultra-large range torque sensor, the maximum deviation between the estimated value and the standard value did not exceed 0.5% FS. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of installing a 2.5MN·m ultra-large torque sensor on a 600kN·m torque standard device;

[0024] Figure 2 Torque measurement curves for the 100 kN·m and 500 kN·m ranges;

[0025] Figure 3 Comparison of linear fitting error ratio curves of torque measurement in 100kN·m and 500kN·m range segments and after linear scaling and extrapolation. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0027] The present invention provides a method for calibrating a torque in an ultra-large range segment. By calibrating the torque value in a smaller range of the torque sensor, a reasonable estimate of the torque value in a larger range is made by means of a linear extrapolation method, thereby achieving torque calibration in an ultra-large range segment. The torque range segment to be calibrated exceeds the maximum range that can be calibrated by a traditional torque measurement standard device. Specifically, the torque value to be measured often needs to reach at least 1.5MN·m, and even under certain conditions, the torque value to be measured may reach 5MN·m or above, which exceeds the calibration capability of the current torque standard device.

[0028] The linear extrapolation method first completes the calibration within the smaller range of the sensor based on the calibration capability of the traditional torque measurement standard device. Then, by determining the range magnification and the linear extrapolation coefficient of different measuring points, linear extrapolation is performed based on a certain formula to calculate the torque value estimation result under the ultra-large range segment.

[0029] Based on the above-mentioned technical solution, taking the 2.5MN·m ultra-large torque sensor as an example, the ultra-large range torque calibration method of the present invention is applied, and the calibration test process and the extrapolation estimation calculation results are as follows:

[0030] First, install the 2.5MN·m ultra-large torque sensor on the 600kN·m torque standard device. Figure 1 As shown in the figure, torque calibration is carried out in the 100kN·m and 500kN·m ranges, respectively, with 10 measuring points selected in each range:

[0031] The torque setting values ​​in the 0-100kN·m range are 10kN·m, 20kN·m, 30kN·m, 40kN·m, 50kN·m, 60kN·m, 70kN·m, 80kN·m, 90kN·m and 100kN·m respectively;

[0032] The torque setting values ​​in the 0-500kN·m range are 50kN·m, 100kN·m, 150kN·m, 200kN·m, 250kN·m, 300kN·m, 350kN·m, 400kN·m, 450kN·m and 500kN·m respectively;

[0033] The full range section of 0-2.5MN·m is extrapolated based on the calibration data of the range section of 0-500kN·m. The three ranges are 5 times each other. According to formula (1), the coefficient of extrapolation from the 100kN·m range section to the 500kN·m range section can be used to make an approximate extrapolation estimate of the 500kN·m range section to the 2.5MN·m range section.

[0034] According to the ultra-large range torque calibration method, during the small range calibration of the 2.5MN·m ultra-large torque sensor, each test point is stopped until the instrument display is stable, and the clockwise and counterclockwise loading and unloading are repeated three times in a row. The measurement data of each point is recorded, and the measurement is not cleared during the measurement. In the data processing, the three sets of repeated test data are averaged and linearly fitted, and the measurement error ratio is calculated according to formula (2) to draw the curve. Among them, the torque measurement curves of the 2.5MN·m ultra-large torque sensor in the 100kN·m and 500kN·m ranges are shown as follows: Figure 2 As shown, the linear fitting error ratio curve of torque measurement is as follows: Figure 3 As shown:

[0035] Considering that the 600 kN·m measuring device has a large error in the 100 kN·m range, especially in the measurement range of ±10-50 kN·m, and it is observed that the trends in the second half of clockwise loading and counterclockwise loading are basically consistent, which can basically reflect the change trend of the measurement error between large and small ranges. Therefore, the linear scaling calculation method is continued to be used to extrapolate the measurement results of the 500 kN·m range. According to formula (1):

[0036]

[0037] Among them, from the 500kN·m range to the 2.5MN·m range, m l That is, the linear extrapolation coefficient between the extrapolation range and the measurement range is 5, k lThat is, the linear extrapolation coefficient of the torque measurement deviation part is based on the conclusion of linear scaling of the curve trend between the 100kN·m range segment and the 500kN·m range segment. The scaling calculation is performed on the basis of the proportion of fitting errors between the measurement results and the calibration results in the 500kN·m range segment. The linear extrapolation coefficient of the clockwise part is 0.2068 (that is, the proportion of fitting errors after the range is magnified by 5 times is 0.2068 times before the magnification, the same below), and the linear extrapolation coefficient of the counterclockwise part is 0.2145. The specific calculation results are shown in the following table:

[0038] Extrapolation estimation results of linear scaling of the 500 kN·m range segment to the 2.5 MN·m super-large range segment

[0039]

[0040] Note: Clockwise torque is recorded as a positive number, and counterclockwise torque is recorded as a negative number.

[0041] According to the data in the table, the extrapolated estimation results of each measuring point are very close to the corresponding torque standard value in the table, and the maximum deviation between the extrapolated estimation value and the standard value does not exceed 0.5% FS, which shows that the linear extrapolation estimation method works well in the 2.5MN·m ultra-large torque sensor.

Claims

1. A method for calibrating torque in an ultra-large range, which is used for calibrating torque in a range beyond the maximum range that can be calibrated by a traditional torque measurement standard device, and is characterized by: The linear fitting extrapolation method is adopted. First, the torque standard value part and the torque measurement deviation part are calculated separately, and then the calculation results of the two parts are adjusted by different extrapolation coefficients to obtain the linear extrapolation calculation value after the expanded range.

2. The ultra-large range torque calibration method according to claim 1, characterized in that: The specific calculation method of the linear fitting extrapolation method is as follows: In formula (1): y i ex —Extrapolation result of the i-th torque value; —The standard value corresponding to the i-th torque measurement value; m l —Linear extrapolation coefficient of extrapolation range and measurement range; k l —Linear extrapolation coefficient of the deviation part of torque measurement; Δx i —The error offset ratio of the i-th torque value satisfies the following formula: In formula (2): x i — the i-th torque measurement value; —The standard value corresponding to the i-th torque measurement value; From formula (1), we can see that the key to the linear fitting extrapolation method lies in the extrapolation coefficient m l and k l The selection of l It can be directly determined by the magnification between different ranges, but k l It is determined by the amplitude parameters of the partial segment and the ratio of the full-scale to the partial segment amplitudes; usually, this amplitude ratio is unknown but is estimated by measuring different partial segments.

3. The ultra-large range torque calibration method according to claim 2, characterized in that: According to the linear fitting extrapolation method, by obtaining multiple amplitudes and linearly extrapolating the amplitude of the full range segment, and then with the help of the extrapolation estimation curve, k can be roughly obtained. l The value of extrapolation coefficient m is determined l and k l Afterwards, the extrapolated estimate can be finally calculated.

4. The ultra-large range torque calibration method according to claim 1, characterized in that: The torque is measured using an ultra-large torque sensor installed on a torque standard device to obtain torque measurement curves in different ranges.

5. The ultra-large range torque calibration method according to claim 1, characterized in that: The calculation results of the two parts are adjusted by using different extrapolation coefficients to obtain a comparison of the linear fitting error ratio curves of torque measurement after different measuring ranges and linear scaling extrapolation.

Images