Self-test intelligent rotary tillage blade and self-test method

Abstract

The application discloses a self-test intelligent rotary tillage blade, which comprises a rotary tillage blade, a strain gauge, a signal conditioning module and an upper computer, wherein the strain gauge is installed at a slot of a handle reinforcing rib of the rotary tillage blade, the signal conditioning module is used for converting a strain resistance signal output by the strain gauge into a corresponding strain voltage signal and pre-processing the strain voltage signal, and the upper computer is used for obtaining a strain measured by the strain gauge according to the pre-processed strain voltage signal and a sensitivity coefficient of the strain gauge and obtaining a stress at the slot of the handle reinforcing rib of the rotary tillage blade according to the strain measured by the strain gauge and a Young's modulus of a material of the rotary tillage blade. The application can accurately detect the size of the surface pressure of the rotary tillage blade under different working environments.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery and equipment technology, specifically to an intelligent rotary tiller blade and its self-testing method for self-testing rotary tillage force. Background Technology

[0002] Rotary tillage blades are the core tillage component of a rotary tiller, responsible for cutting, crushing, mixing, and shredding soil and straw. The structural parameters of the blades directly affect the machine's operational quality, power consumption, wear, and lifespan. Due to the promotion of conservation tillage systems and the extensive use of pesticides and fertilizers, soil surface firmness has changed significantly, potentially causing rotary tillage blades to break due to variations in resistance during use. Furthermore, due to regional differences in soil conditions and planting systems, rotary tillage machines with distinct regional characteristics have emerged. Crop planting conditions and methods also place new demands on these machines, necessitating research into the deformation and stress patterns of the blades during the cutting process. The blades, in contact with the soil, process it while simultaneously experiencing a reaction force from the soil. This force forms the basis for studying the cutting process and is crucial for guiding the optimal design of the blades, both theoretically and practically. Therefore, it is essential to measure the forces acting on the rotary tillage blades and monitor changes in surface pressure during operation.

[0003] Currently, the force measurement of rotary tillers during operation is achieved by constructing a test bench and installing triaxial force sensors on the rotary tiller shaft for analysis and measurement. This technology uses an initial position sensor and an angle sensor to identify protrusions on the continuously rotating initial position disk and indexing disk, respectively, and generates pulse signals. Each triaxial force data point is correlated with the rotation angle, and coordinate transformation is performed through corresponding numerical calculations to obtain the relationship between the triaxial force on the continuously rotating tiller roller and the rotation time and angle of the roller, thus completing the triaxial force measurement. Another type of self-excited vibration rotary tiller blade force and vibration detection device includes a vibration measurement module, a posture measurement module, and a pressure measurement module. Based on the processed and restored original signal waveform, the acceleration values ​​of the blade along the x, y, and z spatial degrees of freedom, as well as the rotation angle values ​​around these three degrees of freedom, can be obtained. After signal analysis and processing, the displacement, force, angle, and torque values ​​in the corresponding degrees of freedom directions are obtained.

[0004] These measurement methods cannot directly measure the force on the rotary tiller blades, and the data acquisition process is relatively complex. Furthermore, data cannot be transmitted in real time, and triaxial force sensors are expensive. All of these factors contribute to the difficulty in measuring the surface pressure of the rotary tiller blades. Additionally, the sensors are essentially exposed, making them susceptible to scratches and resulting in a short lifespan. Moreover, existing technologies rely on laboratory test benches and cannot perform measurements under real-world working conditions. Therefore, there is a need to design a low-cost, wirelessly data-transmitting, long-life intelligent rotary tiller blade capable of self-measuring rotary tillage force. Summary of the Invention

[0005] The purpose of this invention is to provide an intelligent rotary tiller blade and a self-testing method for measuring the stress of rotary tillage. This invention can accurately detect the magnitude of the surface pressure of the rotary tiller blade under different working environments and display it on a host computer interface to analyze the surface pressure at the reinforcing ribs of the rotary tiller blade during operation.

[0006] To achieve this objective, the present invention designs an intelligent rotary tiller blade that can self-measure the stress of rotary tillage. It includes a rotary tiller blade, a strain gauge, a signal conditioning module, and a host computer. The strain gauge is installed at the groove of the reinforcing rib of the blade handle. The signal conditioning module is used to convert the strain resistance signal output by the strain gauge into a corresponding strain voltage signal and preprocess the strain voltage signal. The host computer is used to obtain the strain measured by the strain gauge based on the preprocessed strain voltage signal and the sensitivity coefficient of the strain gauge, and to obtain the stress at the groove of the reinforcing rib of the blade handle based on the strain measured by the strain gauge and the Young's modulus of the rotary tiller blade material.

[0007] The beneficial effects of this invention are:

[0008] This invention embeds strain gauges into the reinforcing ribs of the rotary tiller blade handle, fixes them with silicone rubber, and encapsulates them with silicone rubber. This allows for direct measurement of the real-time surface pressure at the reinforcing ribs of the rotary tiller blade, preventing scratches during operation and extending the sensor's lifespan.

[0009] This invention uses wireless sensing technology to reduce the number of wires and prevent wire tangling. It can more directly, accurately and conveniently measure the surface pressure of rotary tillers under different working environments. It solves the problem of inaccurate testing caused by indirectly measuring the pressure on the surface of rotary tillers by measuring other parts of the rotary tiller in the previous testing process, as well as the problem of the high cost of using three-dimensional force sensors. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0011] Figure 2 for Figure 1 Top view of the rotary tiller section;

[0012] Figure 3 This is a schematic diagram of the strain gauge installed at the groove of the reinforcing rib of the rotary tiller handle in this invention;

[0013] Figure 4 This is a schematic diagram of the single-bridge circuit of the conditioning module in this invention;

[0014] Figure 5 This is a schematic diagram of the conditioning module in this invention;

[0015] Figure 6 This is a three-dimensional structural diagram of the rotary tillage blade part in this invention.

[0016] Among them, 1—rotary tillage blade, 2—blade roller, 3—signal conditioning module, 4—data acquisition card, 5—host computer, 6—wire, 7—strain gauge, 8—grooving of the blade handle reinforcing rib. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0018] like Figures 1-6 This invention discloses an intelligent rotary tiller blade that self-measures the stress of rotary tillage. It includes a rotary tiller blade 1, a strain gauge 7, a signal conditioning module 3, and a host computer 5. The strain gauge 7 is installed at the groove 8 of the reinforcing rib of the blade handle 1. The signal conditioning module 3 converts the strain resistance signal output by the strain gauge 7 into a corresponding strain voltage signal and preprocesses the strain voltage signal. The host computer 5 obtains the strain measured by the strain gauge 7 based on the preprocessed strain voltage signal and the strain gauge sensitivity coefficient, and obtains the stress at the groove 8 of the reinforcing rib of the blade handle 1 based on the strain measured by the strain gauge 7 and the Young's modulus of the rotary tiller blade material. The reinforcing rib of the rotary tiller blade is prone to breakage; measuring the stress at this location can more accurately reflect the material state of the rotary tiller blade and prevent the rotary tiller blade 1 from breaking due to excessive stress.

[0019] In the above technical solution, the strain gauge 7 is pasted and embedded in the groove 8 of the reinforcing rib of the rotary tiller 1 handle.

[0020] In the above technical solution, the specific method for attaching and embedding the strain gauge 7 into the groove 8 of the reinforcing rib of the rotary tiller 1 handle is as follows:

[0021] First, a first layer of silicone rubber is used to attach the strain gauge 7 to the groove 8 of the reinforcing rib on the handle of the rotary tiller 1. Then, a second layer of silicone rubber is applied over the strain gauge 7 for encapsulation and protection. A metal plate of the same material as the rotary tiller 1 is then welded onto the outer layer of the second layer of silicone rubber to prevent scratching during operation and extend the sensor's lifespan. The thickness of the second layer of silicone rubber is greater than that of the first layer. The thickness of the second layer ranges from 1 to 2 mm, while the thickness of the first layer ranges from 0.1 to 0.5 mm. The first layer of silicone rubber is used to attach the strain gauge, and the second layer is used for encapsulation and protection. Embedding the strain gauge inside the rotary tiller and encapsulating it with silicone rubber and a metal plate prevents damage to the strain gauge during operation and prevents moisture from directly contacting the strain gauge, thus increasing the sensor's lifespan.

[0022] In the above technical solution, the single-bridge circuit (bridge voltage 2.5V) in the signal conditioning module 3 converts the strain resistance signal output by the strain gauge 7 into a corresponding strain voltage signal. The single-bridge circuit includes resistors R1, R2, and R3, and a DC power supply V. One end of resistor R1 is connected to one end of the strain gauge 7's resistance, and the other end of resistor R1 is connected to one end of resistor R2. The other end of resistor R2 is connected to one end of resistor R3, and the other end of resistor R3 is connected to the other end of the strain gauge 7's resistance. One terminal of the DC power supply V is connected to one end of resistor R2, and the other terminal of the DC power supply V is connected to the other end of resistor R3. The strain voltage signal Ve is output between one end of resistor R1 and the other end of resistor R2. The above single-bridge circuit is a Wheatstone bridge, which converts the strain gauge resistance change into a voltage change, facilitating subsequent signal processing.

[0023] In the above technical solution, the preprocessing of the strain voltage signal Ve includes filtering and amplification to obtain the preprocessed strain voltage signal V1. The filtering is a low-pass filter, which leaves a signal below 800Hz and removes noise interference signals.

[0024] In the above technical solution, the specific method by which the host computer 5 obtains the strain measured by the strain gauge 7 based on the preprocessed strain voltage signal and the strain gauge sensitivity coefficient is as follows:

[0025]

[0026] Where ε represents the strain measured by the strain gauge, V1 represents the pre-processed strain voltage signal, V2 represents the voltage across strain gauge 7, and K represents the sensitivity coefficient of strain gauge 7. S The gain coefficient of the variable voltage signal Ve is represented by n, and the number of strain gauges is represented by n. The sensitivity coefficient K of strain gauge 7 is an inherent parameter of the strain gauge, and its detection method is as follows:

[0027] K = (ΔR / R) / (Δl / l) where R represents the resistance of the strain gauge under no pressure, ΔR represents the change in resistance of the strain gauge under pressure, l represents the length of the strain gauge under no pressure, and Δl represents the change in length of the strain gauge under pressure.

[0028] The above method can quickly and accurately obtain the strain measured by the strain gauge, thereby reflecting the stress on the rotary tiller blade in real time.

[0029] In the above technical solution, the specific method for obtaining the stress at the groove 8 of the reinforcing rib of the rotary tiller 1 based on the strain measured by strain gauge 7 and the Young's modulus of the rotary tiller material is as follows:

[0030] σ=E*ε

[0031] Where σ represents the stress at the groove 8 of the reinforcing rib of the rotary tiller blade 1, ε represents the strain measured by the strain gauge, and E represents the Young's modulus of the rotary tiller blade material.

[0032] The above technical solution also includes a data acquisition card 4. The rotary tiller 1's blade roller 2 is a segmented rotary tiller blade roller, with adjacent blade roller 2 connected by interlocking sections and fixed by bolts. The signal conditioning module 3 and the data acquisition card 4 are magnetically fixed to the inner wall of the blade roller 2. The strain gauge 7 is connected to the conditioning circuit 3, which is magnetically fixed inside the segmented rotary tiller blade roller, via a wire 6. The data acquisition card 4 is used to acquire the pre-processed strain voltage signal output by the signal conditioning module 3 and transmit the pre-processed strain voltage signal to the host computer 5 via Bluetooth communication. The segmented blade roller facilitates the installation and removal of sensors, and the conditioning circuit and Bluetooth acquisition card are installed inside the blade roller, reducing the number of wires and preventing wire tangling during operation.

[0033] In the above technical solution, when the rotary tiller 1 is working, the strain measured by the strain gauge 7 is combined with the Young's modulus of the rotary tiller material to obtain the stress on the rotary tiller and the strain voltage signal Ve output by the single bridge circuit in the corresponding signal conditioning module 3. The relationship curve between the stress on the groove 8 of the handle reinforcing rib of the rotary tiller 1 and the corresponding strain voltage signal Ve is obtained.

[0034] The rotary tiller blade 1 is fixed on a pressure testing machine, and a force F of known magnitude is applied multiple times to the strain gauge 7 through the pressure testing machine. n Each force applied to strain gauge 7 causes the single-bridge circuit in conditioning module 3 to obtain a corresponding strain voltage signal Ve.

[0035] Obtain multiple forces F of known magnitude n The relationship curve between the voltage signal Ve and the strain voltage signal;

[0036] The relationship curve between the stress and the corresponding strain voltage signal Ve at the grooved part 8 of the handle reinforcing rib of rotary tiller blade 1 is compared with the curve of multiple forces F of known magnitude. n The relationship curve between the stress detection result of the present invention and the corresponding strain voltage signal Ve is compared to verify the stress detection result of the present invention.

[0037] A method for testing the force exerted by rotary tillers during rotary tillage, comprising the following steps:

[0038] Step 1: Install the strain gauge 7 at the groove 8 of the reinforcing rib of the rotary tiller blade 1 handle;

[0039] Step 2: When the rotary tiller 1 is not in working state, initialize the pre-processed strain voltage signal output by the signal conditioning module 3 to set the voltage signal to zero. When installing the strain gauge, the strain gauge 7 should be flat. When the rotary tiller 1 is not under stress, the strain gauge 7 may still have a reading. Record the reading at this time as 0; or record the reading when it is not under stress, and subtract the reading when it is not under stress from the subsequent readings to ensure the accuracy of the stress calculation in the subsequent calculations.

[0040] Step 3: When the rotary tiller 1 is working, the strain gauge 7 is subjected to stress, causing its resistance value to change. The signal conditioning module 3 converts the strain resistance signal output by the strain gauge 7 into the corresponding strain voltage signal and preprocesses the strain voltage signal.

[0041] Step 4: The host computer 5 obtains the strain measured by the strain gauge 7 based on the pre-processed strain voltage signal and the strain gauge sensitivity coefficient, and obtains the stress at the groove 8 of the handle reinforcing rib of the rotary tiller 1 based on the strain measured by the strain gauge 7 and the Young's modulus of the rotary tiller material.

[0042] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. An intelligent rotary tiller blade that self-detects the force applied during rotary tillage, characterized in that: It includes a rotary tiller (1), a strain gauge (7), a signal conditioning module (3), and a host computer (5). The strain gauge (7) is installed at the groove (8) of the reinforcing rib of the handle of the rotary tiller (1). The signal conditioning module (3) is used to convert the strain resistance signal output by the strain gauge (7) into a corresponding strain voltage signal and preprocess the strain voltage signal. The host computer (5) is used to obtain the strain measured by the strain gauge (7) based on the preprocessed strain voltage signal and the strain gauge sensitivity coefficient, and to obtain the stress at the groove (8) of the reinforcing rib of the handle of the rotary tiller (1) based on the strain measured by the strain gauge (7) and the Young's modulus of the rotary tiller material. The single-bridge circuit in the signal conditioning module (3) converts the strain resistance signal output by the strain gauge (7) into a corresponding strain voltage signal. The single-bridge circuit includes resistors R1, R2, and R3 and a DC power supply V. One end of resistor R1 is connected to one end of the resistance of the strain gauge (7), the other end of resistor R1 is connected to one end of resistor R2, the other end of resistor R2 is connected to one end of resistor R3, the other end of resistor R3 is connected to the other end of the resistance of the strain gauge (7), one pole of the DC power supply V is connected to one end of resistor R2, the other pole of the DC power supply V is connected to the other end of resistor R3, and a strain voltage signal Ve is output between one end of resistor R1 and the other end of resistor R2. The preprocessing of the strain voltage signal Ve includes filtering and amplification to obtain the preprocessed strain voltage signal V1, wherein the filtering is a low-pass filter. The host computer (5) obtains the strain measured by the strain gauge (7) based on the pre-processed strain voltage signal and the strain gauge sensitivity coefficient. The specific method is as follows: Where ε represents the strain measured by the strain gauge, V1 represents the pre-processed strain voltage signal, V2 represents the voltage across the strain gauge (7), and K represents the sensitivity coefficient of the strain gauge (7). S represents the gain coefficient of the variable voltage signal Ve, and n represents the number of strain gauges.

2. The intelligent rotary tiller blade that self-tests rotary tillage force according to claim 1, characterized in that: The strain gauge (7) is attached and embedded in the groove (8) of the handle reinforcing rib of the rotary tiller (1).

3. The intelligent rotary tiller blade that self-tests rotary tillage force according to claim 2, characterized in that: The specific method for attaching and embedding the strain gauge (7) into the groove (8) of the handle reinforcing rib of the rotary tiller (1) is as follows: First, use the first layer of silicone rubber to attach the strain gauge (7) to the groove (8) of the reinforcing rib of the rotary tiller (1). Then, use the second layer of silicone rubber to coat the strain gauge (7) for encapsulation and protection. Then, weld a metal plate of the same material as the rotary tiller (1) to the outer layer of the second layer of silicone rubber.

4. The intelligent rotary tiller blade that self-tests rotary tillage force according to claim 1, characterized in that: The specific method for obtaining the stress at the groove (8) of the reinforcing rib of the rotary tiller (1) based on the strain measured by strain gauge (7) and the Young's modulus of the rotary tiller material is as follows: σ=E*ε Where σ represents the stress at the groove (8) of the handle reinforcing rib of the rotary tiller (1), ε represents the strain measured by the strain gauge, and E represents the Young's modulus of the rotary tiller material.

5. The intelligent rotary tiller blade that self-tests rotary tillage force according to claim 1, characterized in that: It also includes a data acquisition card (4). The rotary tiller (1) has a segmented rotary tiller roller (2). The connecting sections of two adjacent rollers (2) are connected and fixed by bolts. The signal conditioning module (3) and the data acquisition card (4) are installed on the inner wall of the roller (2). The data acquisition card (4) is used to acquire the pre-processed strain voltage signal output by the signal conditioning module (3) and transmit the pre-processed strain voltage signal to the host computer (5) via Bluetooth communication.

6. The intelligent rotary tiller blade that self-tests rotary tillage force according to claim 3, characterized in that: The thickness of the second layer of silicone rubber is greater than the thickness of the first layer of silicone rubber.

7. A method for testing the rotary tillage force of a rotary tiller based on the intelligent rotary tiller blade described in claim 1, characterized in that, It includes the following steps: Step 1: Install the strain gauge (7) at the groove (8) of the handle reinforcing rib of the rotary tiller (1); Step 2: When the rotary tiller (1) is not in operation, initialize the pre-processed strain voltage signal output by the signal conditioning module (3); Step 3: When the rotary tiller (1) is working, the strain gauge (7) is subjected to stress, causing its resistance value to change. The signal conditioning module (3) converts the strain resistance signal output by the strain gauge (7) into the corresponding strain voltage signal and preprocesses the strain voltage signal. Step 4: The host computer (5) obtains the strain measured by the strain gauge (7) based on the pre-processed strain voltage signal and the strain gauge sensitivity coefficient, and obtains the stress at the groove (8) of the handle reinforcing rib of the rotary tiller (1) based on the strain measured by the strain gauge (7) and the Young's modulus of the rotary tiller material.

Images