阅读说明：本技术 基于双通路信号校正的数字式扭矩测量装置和方法 (Digital torque measuring device and method based on double-channel signal correction ) 是由 于泽元 刘成永 梁明明 秦志亮 刘晓炜 谢耘 于 2020-06-04 设计创作，主要内容包括：本发明涉及扭力测量技术领域,具体的说是一种能够有效降低施力位置干扰、精确度高的基于双通路信号校正的数字式扭矩测量装置和方法,其特征在于,设有一杆部,杆部设有两组数据采集组件,每组数据采集组件均包括对称设置在杆部两侧的A面应变传感器和B面应变传感器,每组数据采集组件向数据处理器输出一路测量数据,数据处理器对测量数据进行位置精度校准处理后,输出测力结果,本发明与现有技术相比,具有结构合理、测量精度高等显著的优点。(The invention relates to the technical field of torque measurement, in particular to a digital torque measurement device and a digital torque measurement method based on dual-channel signal correction, which can effectively reduce force application position interference and have high accuracy.)

1. The digital torque measuring device based on double-channel signal correction is characterized in that a rod portion is arranged, the rod portion is provided with two groups of data acquisition assemblies, each group of data acquisition assemblies comprises an A-surface strain sensor and a B-surface strain sensor which are symmetrically arranged on two sides of the rod portion, each group of data acquisition assemblies outputs one channel of measurement data to a data processor, and the data processor outputs a force measurement result after the data processor performs position precision calibration processing on the measurement data.

2. The digital torque measurement device based on dual channel signal correction as claimed in claim 1, wherein the data processor is provided with a position and precision relationship calibration unit and a torsion calculation unit, the position and precision relationship calibration unit stores a relationship function P ═ f (L) between a position L and a precision P, and during torsion measurement, the torsion measurement result is output rapidly by using the measurement data corresponding to the relationship function P ═ f (L) between the position L and the precision P.

3. The digital torque measuring device based on double-channel signal correction as claimed in claim 2, wherein the position and precision relation calibration unit is further provided with a position data and precision data calculation module and a position and precision function fitting module in sequence.

4. A digital torque measurement method based on dual channel signal correction as claimed in any one of claims 1-3, wherein two measurement points are arbitrarily selected at the rod, and a corresponding relationship function P (f) (L) of position information L and precision information P obtained by machine learning or test rules is pre-stored in the position and precision relationship calibration unit for completing the calibration of the position and precision relationship of the current wrench; when the device is used, the current force application position data L is obtained by monitoring two measuring points, and the precision data P is obtained through the function P ═ f (L) stored in the position and precision calibration unit, so that the correction is provided for torque output.

5. The digital torque measurement method based on two-channel signal correction according to claim 4, wherein the position and precision function P ═ f (L) is obtained by:

respectively collecting stress conditions of the first measuring point and the second measuring point under the condition of no force application by using a strain sensor, and respectively recording the stress conditions as A₀And B₀(ii) a Optionally n different points of application i, where n is greater than or equal to 3, applying different standard forces F corresponding to each point of application i_ijThen, respectively obtaining the stress data of a first measuring point and a second measuring point under the condition of applying different standard forces Fij, wherein the stress data of the first measuring point is marked as A_ijAnd the stress data of the second measuring point is recorded as B_ij(ii) a : obtaining multiple sets of position data L by using formula 1 and formula 2_ijAnd precision data P_ij，

L_ij＝(A_ij-A₀)/(B_ij-B₀) (1)，

P_ij＝(A_ij-A₀)/F_ij (2)；

By obtaining a plurality of sets of position data L_ijAnd precision data P_ijTraining to obtain a position accuracy correction function: and f (L), and storing the function for torque force calculation.

6. The digital torque measurement method based on dual channel signal correction as claimed in claim 4, wherein the torque force is obtained by:

applying force to the wrench, and calculating the force application position value L according to the force application data output by the first measuring point and the second measuring point_sWherein the stress data of the first measuring point is recorded as A_sAnd the stress data of the second measuring point is recorded as B_s，L_s＝(A_s-A₀)/(B_s-B₀) (ii) a Calculating the torque accuracy based on the position value L_sThe sum function P ═ f (L) yields the torque accuracy value P_s(ii) a Calculating the applied torque N_sUsing the formula N_s＝(A_s-A₀)/P_sCalculating a torque force value N_s。

The technical field is as follows:

the invention relates to the technical field of torque measurement, in particular to a digital torque measurement device and method based on dual-channel signal correction, which can effectively reduce force application position interference and has high accuracy.

Background art:

digital torque measuring devices such as digital torque wrenches are widely applied to industries such as machinery, automobiles, shipbuilding, metallurgy, bridges, chemical engineering and the like, and are particularly suitable for situations where early warning torque needs to be applied or the current torque needs to be known. The application of foreign digital display wrenches is very common, but the price is high; the digital display wrench is produced by enterprises at home, but the measurement precision is different from the reliability of products at abroad. At present, the digital display wrenches at home and abroad mostly adopt the measurement principle of a Wheatstone bridge, torque change is converted into electric signal change through a resistance type strain sensor, a signal conditioning circuit is used for amplifying and filtering weak electric signals, the weak electric signals are transmitted to a single chip microcomputer for processing after A/D conversion, corresponding torque values are calculated by combining compensation parameters, and finally the corresponding torque values are displayed through an LCD.

The sticking position of a resistance type strain sensor on the existing digital torque wrench can cause great influence on the torque measurement precision, theoretically, when the sticking position of the resistance type strain sensor is superposed with a twisting head, the torque borne by the twisting head is equal to the bending torque borne by the resistance type strain sensor, so that the torque measured by the resistance type strain sensor can be ensured to be the torque borne by the twisting head, and the torque measurement is not influenced by the position of a force application point; in fact, the sticking position of the resistance strain sensor cannot coincide with the screw head, so that there are several solutions at present. (1) A resistance-type strain sensor is pasted at a position as close to a screwing head as possible, and the torque measurement error of the wrench is ensured to be within an allowable range through the structural size design of the wrench. However, the scheme of judging the current torque value by using the AD signals differentially amplified at the two ends of the strain sensor through hardware limits the installation position and the length of the force arm of the strain sensor, and is only suitable for the sleeve type torque wrench with the strain sensor attached to the rod head. The part of the wrench is greatly limited in process and use scenes. (2) A strain sensor is pasted between a wrench head and a handle, torque is measured through bending moment, a special Wheatstone bridge is used, the pasting mode of the strain sensor, the distance between the strain sensors and the resistance value of the strain sensor are regulated, a calculation formula is deduced, and finally a torque measurement value is deduced. However, the method has strict regulations on the parameters, the pasting mode and the position of the strain sensor, and the final measurement accuracy can be directly influenced by the parameter error and the structural process error of the chip.

The invention content is as follows:

aiming at the defects and shortcomings in the prior art, the invention provides a digital torque measuring device and method based on double-channel signal correction, which can enable the torque measurement value not to be influenced by the installation position of a strain sensor or the force application position on a handle and can realize that the length of a wrench force arm and the torque measurement range are not limited by a torque calculation method.

The invention can be achieved by the following measures:

the digital torque measuring device based on double-channel signal correction is characterized in that a rod portion is arranged, the rod portion is provided with two groups of data acquisition assemblies, each group of data acquisition assemblies comprises an A-surface strain sensor and a B-surface strain sensor which are symmetrically arranged on two sides of the rod portion, each group of data acquisition assemblies outputs one channel of measurement data to a data processor, and the data processor outputs a force measurement result after the data processor performs position precision calibration processing on the measurement data.

The data processor is provided with a position and precision relation calibration unit and a torsion calculation unit, wherein the position and precision relation calibration unit stores a relation function P (f) (L) of a position L and a precision P, and a torsion measurement result is rapidly output through measuring the relation function P (f) (L) of the position L and the precision P corresponding to data in the torsion measurement process.

The position and precision relation calibration unit is further sequentially provided with a position data and precision data calculation module and a position and precision function fitting module.

The two groups of data acquisition assemblies of the rod part are arranged along a straight line, and in order to facilitate the installation of the strain sensor, installation grooves can be correspondingly formed in two sides of the rod part respectively.

The invention also provides a digital torque measurement method based on double-channel signal correction, which is characterized in that two measurement points are arbitrarily selected at the rod part, and a corresponding relation function P (f) (L) of position information L and precision information P acquired by using a machine learning or testing rule is prestored in a position and precision relation calibration unit and is used for completing the position and precision relation calibration of the current digital torque force measurement device; when the device is used, the current force application position data L is obtained by monitoring two measuring points, and the precision data P is obtained through the function P ═ f (L) stored in the position and precision calibration unit, so that the correction is provided for torque output.

In the digital torque measurement method based on two-channel signal correction, the position and precision function P ═ f (l) is obtained by the following method:

respectively collecting stress conditions of the first measuring point and the second measuring point under the condition of no force application by using a strain sensor, and respectively recording the stress conditions as A₀And B₀(ii) a Optionally n different points of application i, where n is greater than or equal to 3, applying different standard forces F corresponding to each point of application i_ijThen, respectively obtaining the stress data of a first measuring point and a second measuring point under the condition of applying different standard forces Fij, wherein the stress data of the first measuring point is marked as A_ijAnd the stress data of the second measuring point is recorded as B_ij(ii) a : obtaining multiple sets of position data L by using formula 1 and formula 2_ijAnd precision data P_ij，

L_ij＝(A_ij-A₀)/(B_ij-B₀) (1)，

P_ij＝(A_ij-A₀)/F_ij (2)；

By obtaining a plurality of sets of position data L_ijAnd precision data P_ijTraining to obtain a position accuracy correction function: and f (L), and storing the function for torque force calculation.

The invention relates to a digital torque measuring method based on double-channel signal correction, wherein the torque is obtained by the following steps:

applying force to the digital torque measuring device, and calculating the force application position value L according to the force application data output by the first measuring point and the second measuring point_sWherein the stress data of the first measuring point is recorded as A_sAnd the stress data of the second measuring point is recorded as B_s，L_s＝(A_s-A₀)/(B_s-B₀) (ii) a Calculating torque precision, and obtaining torque precision value P according to position value Ls and function P ═ f (L)_s(ii) a Calculating the applied torque N_sUsing the formula N_s＝(A_s-A₀)/P_sCalculating a torque force value N_s。

The digital torque measuring device can be a digital torque wrench, a torque measuring instrument, torque wrench calibration equipment, a mechanical arm with a force application or force measurement function and the like.

Compared with the prior art, the digital torque measuring device has the advantages that two groups of data acquisition assemblies are arranged at the rod part of the digital torque measuring device to acquire two paths of force measurement data, then the position and precision correction function P ═ f (L) of the digital torque measuring device is utilized to complete force measurement, the hardware part can be realized by only four strain sensors, the circuit structure complexity is low, the position and precision correction function P ═ f (L) of each wrench product is acquired through targeted training or fitting, the subsequent force measurement is ensured, and the digital torque measuring device has the obvious advantages of reasonable structure, high measurement precision and the like.

Description of the drawings:

FIG. 1 is a schematic diagram of the present invention.

Fig. 2 is a schematic diagram of connection of a strain sensor in embodiment 1 of the present invention.

Fig. 3 is a block diagram of a data processor in the present invention.

FIG. 4 is a flow chart of a force measurement method of the present invention.

Reference numerals: the handle comprises a twisting head (1), a connecting part (2) of the twisting head and a rod, a surface A groove (3), a surface B groove (4), a wrench rod part (5), a force arm (6), a handle head part position (7), a handle middle position (8), a handle root part position (9), a data processor (10) and a data acquisition unit (12).

The specific implementation mode is as follows:

the invention provides a digital torque measuring device based on double-channel signal correction, which can enable the measured value of torque not to be influenced by the installation position of a strain sensor or the force application position on a handle, and can realize that the arm length and the torque measuring range of the measuring device are not limited by a torque calculating method.

Example 1:

as shown in fig. 1 and fig. 2, the present embodiment provides a digital torque wrench based on dual channel signal calibration, which includes a wrench head (1), a wrench rod (5), a data processing mechanism (10), and wrench handles (7 to 9); the twisting head (1) is tightly connected with the wrench rod part (5) in the area 2, the data processor (10) is arranged at any position of the wrench rod part (5), and a surface A groove (3) and a surface B groove (4) are symmetrically formed in two sides of the wrench rod part (5) and used for respectively accommodating two strain sensors, namely two strain sensors are attached to each groove; two strain sensors close to the screw head output a first path of signal CH1, and two strain sensors close to the handle output a second path of signal CH 2;

the connection principle of the strain sensor in this example is shown in fig. 4, wherein the strain sensor a1 (close to the screw head (1)) and the strain sensor a2 (close to the handle) are on the same side, the strain sensor B1 (close to the screw head) and the strain sensor B2 (close to the handle) are on the other side, a voltage signal CH1 is output between the strain sensor a1 and the strain sensor B1, a voltage signal CH2 is output between the strain sensor a2 and the strain sensor B2, and the mounting positions of the strain sensors on both sides are symmetrical; the distance between the two strain sensors on the same side is L;

when the handle is used, the force application position of the handle is any position between the head part (7) of the handle and the root part (9) of the handle, the twisting head (1) is used as an original point, the clockwise rotation from the twisting head to the straight line of the handle is used as the forward force application, and the clockwise rotation is used as the reverse force application.

In this example, the data processor (10) is installed at one end of the wrench rod (5) close to the force arm (6) and is responsible for data acquisition, parameter calibration and torque calculation, the working principle is shown in fig. 3, 4 strain sensors in the data acquisition unit (12) output two paths of voltage signal quantities CH1 and CH2(12) together, the voltage signal quantities are converted into digital signals by using a high-precision AD conversion chip, and in the position and precision relation calibration unit (13), the stress data for specifying the reference zero point is two-path data A recorded when the wrench rod is horizontally placed and does not apply force₀、B₀The two-channel data collected in real time is A, B, the standard force applied as a function of the nominal position information L and the precision information P is F, A, B, A₀、B₀And F calculates the position information L and the accuracy information P using the formula L ═ B-B₀)/(A-A₀) As the position information L, useFormula P ═ A-A₀) If L or P is negative, it is indicated as a reverse bias, and the absolute value of L or P is required.

10 wrenches produced in the same batch are selected, and 10 force application points are respectively selected from the front side and the back side of each wrench, wherein the force application points comprise a wrench head (7), the center points of the wrench head (7) and the wrench middle (8), a wrench middle (8), the center points of the wrench middle (8) and the wrench root (9), and the wrench root (9). Taking 85Nm wrench as an example, the range is 10 Nm-85 Nm, standard forces of 17Nm, 25Nm and 51Nm are respectively applied to each selected force application point according to the characteristics of the strain sensor, two channel AD values A and B are respectively recorded, and the formula L is used as (B-B)₀)/(A-A₀) And P ═ a (a-a)₀) A total of 300 sets L and P were calculated by/F. Each set of test data A, B, A₀、B₀And substituting the L and the P into a training module using a logistic regression model to obtain a conversion relation function P (f) (L) between the P and the L, and recording the main parameters of the formula and the calculation flow in a processor.

During actual force application, the torsion computing unit (14) utilizes the received two signals CH1 and CH2(12) and a position information formula to compute the position information L of the force application point, the precision information P is calculated according to the relation function P ═ f (L) of L and P, and finally the torsion obtained through actual computation is N ═ A (A-A)₀)/P。

The data output unit (15) displays real-time torque values, torque units and other wrench parameters on an LCD screen in real time, and uploads data to a computer end for remote display synchronously in a wifi, Bluetooth, USB and other modes.

In the working process, two measuring points are selected at the lever part of the wrench, wherein each measuring point is used for measuring stress data by two strain sensors symmetrically arranged at two sides of the measuring point, each measuring point respectively outputs the stress data to a position and precision calibration unit, the position and precision data are obtained in the position and precision relationship calibration unit through calculation, different standard forces are applied by selecting different positions, the corresponding relationship between position information and precision information is obtained by utilizing a machine learning or testing rule, and a function is obtained by utilizing a position and precision function fitting module, so that the position and precision relationship calibration of the current wrench product is completed; in the process of using the wrench, the current force application position data is obtained by converting the stress data of the two measuring points, and the precision data is obtained by the function stored in the position and precision calibration unit, so that the subsequent torque output is corrected, and the aim of improving the measuring precision is fulfilled.