Non-intrusive torque sensor device and method based on standard elastic pull rod
By using a non-invasive torque sensor based on a standard elastic tie rod, and measuring the tensile stress of the tie rod with strain gauges to calculate the torque, the problems of insufficient versatility and accuracy of non-invasive sensors are solved. This enables rapid installation and disassembly, reduces costs, and improves measurement accuracy.
Patent Information
- Application Number
- CN202511643884.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-11
- Publication Date
- 2026-01-27
AI Technical Summary
Existing non-invasive torque sensors lack versatility and have insufficient measurement accuracy, while invasive measurements require modifications to the original mechanical structure and increase costs.
Design a non-invasive torque sensor based on a standard elastic tie rod. By installing a clamp and a tension sensor on the drive shaft, the torque is calculated by measuring the tensile stress of the tie rod using strain gauges. Wireless power supply and communication modules are used for signal processing to achieve non-invasive torque measurement.
It enables rapid installation and disassembly without damaging the measured shaft, reduces equipment costs, is versatile, has high measurement accuracy, and is easy to maintain.
Smart Images
Figure CN121409480A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of torque measurement, and more specifically, to the design of a non-invasive torque sensor device and method based on a standard elastic tie rod. Background Technology
[0002] Torque is a key parameter for rotating components, characterizing the reliability of rotating equipment during operation. Whether in shipbuilding, aerospace, or various industrial settings, complex mechanical devices rely heavily on rotating parts; therefore, torque has gradually become a typical test quantity reflecting the transmission performance of mechanical devices. It has wide applications in automotive manufacturing, aerospace, and shipbuilding. Torque sensors have permeated various industries, and torque measurement plays a crucial role in the entire industrial process.
[0003] Most rotational torque measurements are invasive, involving embedding sensors in series into the power shaft system (e.g., disconnecting the original shaft and adding the sensor body or a dedicated coupling). Invasive measurements offer advantages such as high precision, excellent dynamic response, and strong anti-interference capabilities. However, this method also has drawbacks: it requires modification of the original mechanical structure, may damage the measured shaft, and increases equipment and maintenance costs. Non-invasive measurements, on the other hand, involve directly attaching sensitive elements such as strain gauges or fiber optic gratings to the measured shaft. This method has no impact on the measured shaft before or after measurement, ensuring no damage to the object being measured. Furthermore, it requires no complex operations, can be completed quickly, and offers low equipment cost and simple maintenance. Non-invasive torque sensors can be detached from the measured shaft at any time, or installed on the shaft for rotational torque measurement. However, existing non-invasive solutions lack versatility and have insufficient measurement accuracy. Summary of the Invention
[0004] To overcome the shortcomings of existing technologies, this invention proposes a non-invasive torque sensor device and method based on a standard elastic tie rod. The torque on the power shaft is transmitted to an external tie rod, and the torque is measured by measuring the tensile stress of the tie rod. After the parameters of the standard elastic tie rod are fixed, only the parameters of the fixing ring need to be designed for different shafts, thus making the torque sensor design scheme universal.
[0005] The objective of this invention can be achieved through the following technical solutions.
[0006] A non-invasive torque sensor device based on a standard elastic tie rod includes a sensing element and a strain gauge signal processing module. The sensing element consists of a clamp and a tension sensor. The clamp includes two parallel and coaxially arranged fixing rings. The tension sensor includes two tie rods and two strain gauges. The two tie rods are located on opposite sides of the two fixing rings and connected between the two fixing rings. The two strain gauges are respectively disposed on the outside of the two tie rods.
[0007] Furthermore, each of the fixing rings adopts the same rectangular structure, and each of the fixing rings adopts a split structure, which is fastened together by bolts.
[0008] Furthermore, the length of the fixing ring is Width is ,in, The diameter of the power shaft is given; the thickness and spacing of the fixed rings are obtained through finite element simulation.
[0009] Furthermore, each of the tie rods adopts the same rectangular structure, and the two tie rods are at an angle of ±45° with the axis of the fixing ring, respectively connected between the outer sides of the two fixing rings.
[0010] Furthermore, the length and width of the tie rod are greater than the length and width of the strain gauge, respectively. One end of the tie rod protrudes outward from the axial direction of the fixing ring, and the protruding part is provided with a threaded hole. The tie rod and the fixing ring are connected by applying preload through bolts.
[0011] Furthermore, the strain gauge signal processing module includes a full-bridge circuit and an AD conversion unit. Two strain gauges are distributed on opposite arms of the full-bridge circuit, and the other two arms are fixed resistors. During measurement, the torque of the power shaft is converted into tensile stress of the tie rod. The strain gauges convert the change in tensile stress into a change in resistance. The full-bridge circuit amplifies and samples the signal. The AD conversion unit converts the analog voltage signal output by the full-bridge circuit into a digital voltage signal and sends it to the host computer for processing via a wireless communication module to obtain the torque of the power shaft.
[0012] Furthermore, the strain gauge signal processing module is powered by a wireless power supply module.
[0013] Furthermore, the formula for calculating the torque of the drive shaft is as follows:
[0014] ,
[0015] In the formula, For the torque of the drive shaft, The tensile stress of the tie rod measured by strain gauges. For the length of the tie rod, The elastic modulus of the tie rod material. For the dynamic axis polar moment of inertia, The distance between the two fixed rings. To fix the radius of the inner hole of the ring, This refers to the shear stress generated on the surface of the power shaft.
[0016] The objective of this invention can also be achieved through the following technical solutions.
[0017] A measurement method for a non-invasive torque sensor device based on a standard elastic tie rod includes the following steps:
[0018] Select strain gauges and design tie rod parameters based on the working conditions of the power shaft;
[0019] Design the retaining ring parameters based on the diameter of the drive shaft;
[0020] Assemble the strain gauge, tie rod, retaining ring, and drive shaft;
[0021] During the rotation of the power shaft, the torque of the power shaft is converted into tensile stress in the tie rod. The strain gauge converts the change in tensile stress into a change in resistance. The digital voltage signal sampled after processing by the strain gauge signal processing module is then sent to the host computer for processing via the wireless communication module to obtain the torque of the power shaft.
[0022] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:
[0023] (1) The clamp fixing ring in this invention is a split type, which is fixed to the outside of the power shaft by bolts. No additional processing is required for the power shaft. It will not affect the shaft being measured before or after measurement, so as not to damage the object being measured. At the same time, no complicated operation is required, and installation and disassembly can be completed quickly. In addition, the equipment cost is low and maintenance is simple.
[0024] (2) When the power shaft rotates, the torque on the power shaft is transmitted to the external tie rod. The torque is measured by measuring the tensile stress of the tie rod. After the tie rod parameters are designed, it is used as a standard elastic tie rod with fixed parameters. When measuring the torque of different power shafts, only the parameters of the fixed ring need to be designed, so that the torque sensor design scheme has universality.
[0025] Instruction manual illustrations
[0026] Figure 1 This is a schematic diagram illustrating the overall principle of the non-invasive torque sensor device based on a standard elastic tie rod according to the present invention.
[0027] Figure 2 This is a schematic diagram of the strain gauge bonding position in the sensitive element of the present invention;
[0028] Figure 3 This is a schematic diagram of the sensitive element (i.e., sensor model) of the present invention;
[0029] Figure 4 This is a schematic diagram of the wireless power supply module and the wireless communication module in this invention;
[0030] Figure 5 This is a flowchart illustrating the workflow of the non-invasive torque sensor device based on a standard elastic tie rod according to the present invention.
[0031] Reference numerals: 1-fixed ring, 2-tension rod, 3-strain gauge, 4-drive shaft. Detailed Implementation
[0032] The present invention will now be further described with reference to the accompanying drawings.
[0033] like Figure 1 As shown, this invention proposes a non-invasive torque sensor device based on a standard elastic tie rod, which mainly includes a sensitive element and a strain gauge signal processing module, and is installed on the outside of the power shaft (such as an elastic shaft) during measurement.
[0034] like Figure 2 and Figure 3 As shown, the sensitive element consists of two parts: a clamp and a tension sensor. The clamp includes two parallel and coaxially arranged fixing rings 1. The tension sensor includes two pull rods 2 and two strain gauges 3. The two pull rods 2 are located on opposite sides of the two fixing rings 1 and connected between the two fixing rings 1. The two strain gauges 3 are respectively disposed on the outside of the two pull rods 2 and are used to measure the tensile stress of the pull rods 2.
[0035] In the aforementioned sensor device, preferably, each of the fixing rings 1 adopts the same rectangular structure (cubic parallelepiped shape), with a drive shaft mounting hole in the center. Each fixing ring 1 adopts a split structure, fastened together by bolts. For example, the connection between the drive shaft 4 and the fixing ring 1 uses eight bolts to apply preload, and all connections use M5 screws. Similarly, the fixing ring 1 and the pull rod 2 also use bolts to apply preload, and their connections also use M5 screws. The length of the fixing ring 1 is... Width is ,in, The diameter is the power shaft diameter; the thickness and spacing of the fixed ring 1 were obtained through finite element simulation.
[0036] In the aforementioned sensor device, preferably, each of the tie rods 2 adopts the same rectangular structure with a rectangular cross-sectional shape. The two tie rods 2 form an angle of ±45° with the axis of the fixing ring 1, and are respectively connected between the outer sides of the two fixing rings 1. After installation, the angle between the two tie rods 2 and the power shaft 4 is ±45°. When the power shaft 4 is subjected to torque, it mainly experiences tensile stress in a direction ±45° to the axis, while the tie rods 2 in the 45° direction only experience tensile stress along the direction of the tie rod 2. The strain gauge 3 should be attached along the direction of the tie rod 2 to measure the tensile stress of the tie rod 2. The torque of the power shaft 4 is converted into tensile and compressive stresses in a direction ±45° to the axis. The shaft torque is measured by establishing the relationship between the tensile stress on the tie rod and the stress on the surface of the power shaft. The length and width of the tie rod 2 are greater than the length and width of the strain gauge 3, respectively. One end of the tie rod 2 protrudes axially outward from the fixing ring 1, and this protruding part is provided with a threaded hole. A bolt is used to apply preload to connect the tie rod 2 and the fixing ring 1.
[0037] In the aforementioned sensor device, preferably, such as Figure 4 As shown, the strain gauge signal processing module includes a full-bridge circuit and an AD conversion unit. The full-bridge circuit can be a Wheatstone bridge circuit, and the symmetrical arrangement of the strain gauges 3 in the circuit can counteract the effects of temperature drift. Two strain gauges 3 are attached to two tie rods 2, and the two strain gauges 3 are simultaneously subjected to tensile stress. The two strain gauges 3 are distributed on opposite arms of the full-bridge circuit, while the other two arms are fixed resistors, thereby achieving circuit compensation and improving measurement accuracy.
[0038] Since the power shaft rotates during operation, a wireless power supply module is required to power the strain gauge signal processing module. The strain gauge signal processing circuit is fixed to the outside of the power shaft and close to the fixing ring, rotating with the power shaft. It has a wireless power supply coil receiver that couples with the transmitter to provide working voltage and transmit energy.
[0039] The wireless power supply module consists of a power transmitter and a power receiver. The power transmitter includes an analog front-end unit, a controller, and a transmitting coil, while the power receiver includes a receiver and a receiving coil. When measuring torque, the receiver and receiving coil are mounted on the drive shaft and rotate with it. The power analog front-end unit, controller, and transmitting coil are mounted on an external fixed bracket and do not rotate with the drive shaft. Power is transferred between the transmitter (including the analog front-end unit and controller shown in the diagram) and the receiver via coils. Both the transmitting and receiving coils are Qi-standard A11 type circular spiral planar coils. The transmitter power management system converts the external input voltage into a voltage that enables the transmitter to operate normally. The analog front-end converts the input DC voltage into an AC voltage signal input to the transmitting coil. The controller regulates the output power of the analog front-end unit. Energy is transferred between the transmitting and receiving coils through coupling. The receiver rectifies the transmitted AC voltage into DC voltage and transmits it to the receiver power management system. The receiver power management system then converts the voltage into a value capable of driving the AD conversion unit and the full-bridge circuit.
[0040] The strain gauge signal processing module also has a wireless signal transmission transmitter for signal transmission to the receiver, transmitting the voltage change values of the strain gauge to the host computer for processing. The wireless communication module mainly consists of a Zigbee wireless communication unit and a serial-to-USB unit. The Zigbee wireless communication unit is divided into a coordinator unit and a terminal unit. The terminal unit is connected to the AD conversion unit in the strain gauge signal processing module, and the coordinator unit is connected to the host computer via the serial-to-USB unit. The terminal unit receives the output signal from the AD conversion unit and then exchanges information with the coordinator unit wirelessly. The coordinator unit transmits the received data to the host computer for data processing via the serial-to-USB unit.
[0041] During the rotation measurement of the power shaft, the torque of the power shaft is converted into tensile stress in the tie rod 2. The strain gauge 3 converts the change in tensile stress into a change in resistance. The signal is amplified and sampled by a full-bridge circuit. The AD conversion unit converts the analog voltage signal output by the full-bridge circuit into a digital voltage signal, which is then sent to the host computer for processing via a wireless communication module. In the host computer, the received voltage value is converted into the corresponding tensile stress in the tie rod. Then, the torque of the drive shaft is obtained using the following formula (6). .
[0042] To achieve non-invasive torque measurement, the torque experienced by the drive shaft needs to be converted into a physical quantity on an external component. Let the strain gauge measure the tensile stress in the tie rod as... The radius of the drive shaft is The dynamic axial polar moment of inertia is The torque of the drive shaft is Assuming there is no sliding friction at the contact surface between the fixed ring and the drive shaft, and the Coulomb static friction condition is met, the stress transfer relationship is as follows:
[0043] (1),
[0044] When the drive shaft is subjected to torque, a torsion angle will be generated between the two retaining rings. This causes the tie rod to be subjected to tension or compression. This produces tensile or compressive displacement. Tensile stress is generated on the surface of the tie rod. Shear stress is generated on the surface of the drive shaft. Due to the torque applied, the drive shaft will experience a certain degree of torsion internally, with a torsion angle of [value missing]. The surface displacement generated after torsion is Therefore, the unit torsional angle of the drive shaft is:
[0045] (2),
[0046] When the constraint on the drive shaft at the fixed ring is an ideal rigid constraint, meaning there is no displacement or rotation between the drive shaft and the fixed ring, and the deformation of the drive shaft is uniform, and the unit torsional angle between the shaft segments of the fixed rings is constant, the torsional angle between the two fixed rings is:
[0047] (3),
[0048] in, This refers to the length of the shaft segment between the two fixed rings (i.e., the distance between the two fixed rings). When a certain torsion angle occurs between the fixed rings, the tie rod will generate a certain tensile or compressive force due to the torsion angle; here, tensile force is used. For example, the force on the tie rod follows the theory of linear elasticity, and therefore can be expressed as:
[0049] (4),
[0050] in, For the stiffness of the tie rod, This represents the relative displacement between the two fixed rings. The elastic modulus of the tie rod material. This is the cross-sectional area (section) of the tie rod. Let be the length of the tie rod. When the radius of the inner hole of the retaining ring is... At that time, the relative displacement between the two fixed rings can be approximated as:
[0051] (5),
[0052] Combining the above formulas, we can obtain:
[0053] (6),
[0054] As shown in the above formula, the torque value is affected by three factors: the drive shaft, the tie rod, and the retaining ring. The parameters of the drive shaft vary depending on the measurement environment. The design of the retaining ring parameters must consider the external dimensions of the drive shaft and is significantly influenced by it. However, when designing the tie rod parameters, for different drive shafts, as long as the strain of the tie rod transmitting torque is within the measurable range of the strain gauge, it can be used regardless of other influencing factors of the drive shaft. Therefore, fixing the tie rod parameters can reduce the number of variables, simplify the sensor design process, and improve the sensor's versatility. Once the materials and dimensions of the drive shaft, retaining ring, and tie rod are determined, the torque on the drive bearing can be measured by measuring the tensile stress in the tie rod.
[0055] Based on the above principles, this invention also proposes a non-invasive torque measurement method based on a standard elastic tie rod, such as... Figure 5 As shown, the process includes the following steps: Selecting strain gauges with appropriate dimensions based on the working conditions of the power shaft, along with suitable strain gauge sensitivity coefficients and resistance values; designing the tie rod parameters based on the strain gauge dimensions; designing the fixing ring parameters based on the power shaft diameter; assembling the strain gauges, tie rods, fixing rings, and power shaft; during the rotation of the power shaft, the power shaft torque is converted into tensile stress in the tie rod. The strain gauges convert the tensile stress change into a resistance change, which is then amplified and sampled by a full-bridge circuit. The AD conversion unit converts the analog voltage signal output by the full-bridge circuit into a digital voltage signal. The wireless power supply module provides the operating voltage, and the sampled digital voltage signal is sent to the host computer via a wireless communication module for processing to obtain the power shaft torque.
[0056] The parameter design of tie rod 2 specifically includes tie rod length, tie rod cross-sectional length (i.e., tie rod width), tie rod cross-sectional width (i.e., tie rod thickness), and distance between the tie rod and the outer tangential surface of the power shaft. Within a certain range, the tie rod cross-sectional length is negatively correlated with the tie rod tensile stress; the tie rod cross-sectional width is also negatively correlated with the tie rod tensile stress; and the distance between the tie rod and the outer tangential surface of the power shaft is positively correlated with the tie rod tensile stress within a certain range. However, for different power shaft designs, the tie rod parameters are not directly related to the power shaft diameter. Therefore, when establishing the sensor model, appropriate tie rod parameters can be directly designed, thus ignoring the tie rod parameters during sensor model establishment. Considering the stress concentration problem at the edge of the tie rod and the need to attach strain gauges to the tie rod, the cross-sectional dimensions of the tie rod cannot be too small. Simultaneously, the protruding part on one side of the tie rod has a threaded hole, and preload is applied by bolts, ensuring that tie rod 2 experiences a certain degree of tensile stress even when no torque is applied to the power shaft 4, guaranteeing that the tensile stress variation range of tie rod 2 is within the linear range, and improving the linearity of torque measurement. After the tie rod parameters are designed, this tie rod can be used as a standard elastic tie rod. When measuring different power shafts, only the retaining ring needs to be designed and replaced according to the shaft condition, without redesigning the tie rod.
[0057] Although the parameters of tie rod 2 are not affected by the power shaft 4 within a certain range, they need to be specifically designed in conjunction with the dimensions (length, width, and thickness) of strain gauge 3. For example, if the strain gauge 3 is Lmm long and Wmm wide, the tie rod cross-sectional length can be set to 1.8Wmm to ensure that the strain gauge 3 can fit completely against the tie rod while ensuring high sensitivity of tie rod 2 to stress on the power shaft 4. The tie rod cross-sectional width can be set to 0.9Wmm to simultaneously meet the requirements of high sensitivity and the tie rod tensile stress limit meeting the measurement requirements. The tie rod length should be at least 5 times greater than the strain gauge length; a tie rod length of 8Lmm is recommended. The axial outward tangent distance between tie rod 2 and power shaft 4 should be 8mm. The height of the protruding part on one side of the tie rod can be set to half the width of the fixing ring 1, while its length and width remain consistent with tie rod 2.
[0058] The parameter design of the fixed ring 1 involves four factors: fixed ring length, fixed ring width, fixed ring thickness, and the spacing between the two fixed rings. Considering the design of fixed ring 1, it is closely related to the diameter of the drive shaft 4. Typically, after determining the range of the fixed ring length and width, the focus is on studying the influence of the fixed ring spacing and thickness on the tensile stress of the tie rod. Assume the diameter of the drive shaft is... The length of the retaining ring has almost no effect on the tensile stress of the tie rod, but the length of the retaining ring needs to cover 1 / 3 of the circumference of the drive shaft to evenly distribute the clamping force. Therefore, the length of the retaining ring is designed as follows: mm. Even if the width of the retaining ring exceeds a certain range, it will have almost no impact. However, it is necessary to reserve the corresponding dimension of the axial outward tangential distance between tie rod 2 and drive shaft 4 to ensure the minimum safe distance for connection with tie rod 2. Therefore, the width of the retaining ring is designed to be... mm. The greater the thickness of the retaining ring 1, the greater the tensile stress on the tie rod 2; the greater the spacing between the retaining rings 1, the smaller the tensile stress on the tie rod 2. The retaining ring 1 is installed on the drive shaft 4 by clamping at both ends and fixed by screws. The tie rod 2 is installed on the surface of the rectangular retaining ring and also needs to be pre-tightened with screws. Assume the thickness of the retaining ring is... mm, the spacing between the fixing rings is mm, finite element simulations were performed with different fixing ring thicknesses and spacings to obtain data on the relationship between the tensile stress and parameters of the tie rod. The maximum tensile stress of the tie rod was then calculated. time and The solution yields the thickness of the fixed ring. Spacing with the fixed ring The specific parameters.
[0059] Although the functions and working processes of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific functions and working processes described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these are within the protection scope of the present invention.
Claims
1. A non-invasive torque sensor device based on a standard elastic tension rod, comprising a sensing element and a strain gauge signal processing module, characterized in that, The sensitive element consists of two parts: a clamp and a tension sensor. The clamp includes two parallel and coaxially arranged fixed rings (1). The tension sensor includes two pull rods (2) and two strain gauges (3). The two pull rods (2) are located on opposite sides of the two fixed rings (1) and connected between the two fixed rings (1). The two strain gauges (3) are respectively arranged on the outside of the two pull rods (2).
2. The non-invasive torque sensor device based on a standard elastic tie rod according to claim 1, characterized in that, Each of the fixing rings (1) adopts the same rectangular structure, and each of the fixing rings (1) adopts a split structure and is fastened together by bolts.
3. The non-invasive torque sensor device based on a standard elastic tie rod according to claim 2, characterized in that, The length of the fixed ring (1) is Width is ,in, The diameter of the power shaft is denoted as ; the thickness and spacing of the fixed ring (1) are obtained through finite element simulation.
4. The non-invasive torque sensor device based on a standard elastic tie rod according to claim 1, characterized in that, Each of the tie rods (2) adopts the same rectangular structure. The two tie rods (2) are at an angle of ±45° with the axis of the fixing ring (1) and are respectively connected between the outer sides of the two fixing rings (1).
5. The non-invasive torque sensor device based on a standard elastic tie rod according to claim 4, characterized in that, The length and width of the tie rod (2) are greater than the length and width of the strain gauge (3), and one end of the tie rod (2) protrudes outward from the axial direction of the fixing ring (1). The protruding part is provided with a threaded hole, and the tie rod (2) and the fixing ring (1) are connected by applying preload through bolts.
6. The non-invasive torque sensor device based on a standard elastic tie rod according to claim 1, characterized in that, The strain gauge signal processing module includes a full-bridge circuit and an AD conversion unit. The two strain gauges (3) are distributed on opposite arms of the full-bridge circuit, and the other two arms are fixed resistors. During measurement, the torque of the power shaft is converted into tensile stress of the rod (2). The strain gauges (3) convert the change in tensile stress into a change in resistance. The full-bridge circuit performs signal amplification and sampling processing. The AD conversion unit converts the analog voltage signal output by the full-bridge circuit into a digital voltage signal and sends it to the host computer for processing through the wireless communication module to obtain the torque of the power shaft.
7. The non-invasive torque sensor device based on a standard elastic tie rod according to claim 6, characterized in that, The strain gauge signal processing module is powered by a wireless power supply module.
8. The non-invasive torque sensor device based on a standard elastic tie rod according to claim 6, characterized in that, The formula for calculating the torque of the drive shaft is as follows: ， In the formula, For the torque of the drive shaft, The tensile stress of the tie rod measured by strain gauges. For the length of the tie rod, The elastic modulus of the tie rod material. For the dynamic axis polar moment of inertia, The distance between the two fixed rings. To fix the radius of the inner hole of the ring, This refers to the shear stress generated on the surface of the power shaft.
9. A measurement method for a non-invasive torque sensor device based on a standard elastic tie rod according to any one of claims 1 to 8, characterized in that, Includes the following steps: Select strain gauges and design tie rod parameters based on the working conditions of the power shaft; Design the retaining ring parameters based on the diameter of the drive shaft; Assemble the strain gauge, tie rod, retaining ring, and drive shaft; During the rotation of the power shaft, the torque of the power shaft is converted into tensile stress in the tie rod. The strain gauge converts the change in tensile stress into a change in resistance. The digital voltage signal sampled after processing by the strain gauge signal processing module is then sent to the host computer for processing via the wireless communication module to obtain the torque of the power shaft.