Granular fertilizer flow detection device and fertilizer applicator

Abstract

This invention provides a granular fertilizer flow rate detection device, comprising: an airflow auxiliary device and a granular fertilizer flow rate detection sensor; the airflow auxiliary device is generally cylindrical, comprising, from top to bottom, a fertilizer inlet, a guiding section, a converging section, and a stabilizing section; after the granular fertilizer flows out from the lower end of the variable diameter pipe, it gradually converges in the converging section under the action of the airflow discharged from the airflow auxiliary device, forming a stable cylindrical fertilizer flow in the stabilizing section; the granular fertilizer flow rate detection sensor is located in the stabilizing section to detect the real-time flow rate of the granular fertilizer flow. The granular fertilizer flow rate detection device provided by this invention, by setting up the airflow auxiliary device to form a stable cylindrical fertilizer flow, makes the granular fertilizer flow rate detected by the granular fertilizer flow rate detection sensor more accurate.

Description

Technical Field

[0001] This invention relates to the field of smart agriculture technology, and in particular to a pellet fertilizer flow detection device and a fertilizer applicator. Background Technology

[0002] Reducing fertilizer application while increasing efficiency is a crucial measure to ensure the sustainable development of agricultural production. Precision fertilization technology is one of the technical means to achieve this. Currently, most precision fertilization operations in production utilize precision variable-rate fertilization equipment. This equipment integrates technologies such as satellite positioning, motor / electro-hydraulic control, and sensors. Through its precision variable-rate fertilization control system, the equipment accurately positions and applies fertilizer in variable quantities, thereby improving fertilizer utilization, reducing fertilizer application, and increasing fertilization efficiency.

[0003] In the existing technology, in the flow monitoring scheme of granular fertilizer, the fertilizer is dispersed and uniformly distributed through the turbine guide mechanism, the laser emission module emits light that passes through the fertilizer, and the amount of light after being blocked is collected. The photoelectric sensing circuit outputs the processed voltage signal, which is then filtered by the digital signal processing (DSP) module to obtain the flow data.

[0004] However, in the existing technology that uses a turbine guide device to break up large-volume granular fertilizer before flow detection, the turbine blades are prone to fertilizer sticking and are difficult to rotate due to the impact force of the falling fertilizer. At the same time, the linear laser emitter generates a lot of heat, and its performance will be affected by long-term operation. All of these factors lead to inaccurate granular fertilizer flow detection results. Summary of the Invention

[0005] This invention provides a granular fertilizer flow detection device and a fertilizer applicator to solve the technical problem of inaccurate granular fertilizer flow detection results in the prior art.

[0006] This invention provides a granular fertilizer flow detection device, comprising:

[0007] Airflow assist device and granular fertilizer flow detection sensor;

[0008] The airflow assist device is generally cylindrical, and from top to bottom it includes a fertilizer inlet, a guide section, a converging section, and a stabilizing section.

[0009] The fertilizer inlet is connected to the fertilizer outlet of the fertilizer discharger;

[0010] The guide section consists of an air inlet, an outer shell, a reducing pipe, and an air guide port. The upper end of the reducing pipe is connected to the air inlet, and the lower end of the reducing pipe is connected to the upper end of the converging section. The diameter of the upper end of the reducing pipe is larger than the diameter of the lower end of the reducing pipe. The air guide port is located at the connection between the lower end of the reducing pipe and the upper end of the converging section.

[0011] The air inlet is connected to the fan outlet. The airflow enters the air cavity formed between the outer shell and the reducing pipe from the air inlet and is discharged from the air guide port.

[0012] After the granular fertilizer flows out from the lower end of the reducing pipe, it gradually converges in the converging section under the action of the airflow discharged from the air guide port, and forms a stable cylindrical fertilizer flow in the stabilizing section.

[0013] The granular fertilizer flow detection sensor is set in the stable section to detect the real-time flow rate of the granular fertilizer.

[0014] In some embodiments, the granular fertilizer flow detection sensor includes a light emitter, a light receiver, a current-to-voltage conversion circuit, an analog-to-digital conversion module, and a data processing module;

[0015] The optical transmitter and optical receiver are respectively located on both sides of the stable section of the circular tube;

[0016] After the light emitted by the light emitter is blocked by the cylindrical fertilizer stream, the remaining light is received by the light receiver, thereby generating a current signal corresponding to the diameter of the cylindrical fertilizer stream.

[0017] The input terminal of the current-to-voltage conversion circuit is connected to the output terminal of the optical receiver, and the current-to-voltage conversion circuit converts the current signal generated by the optical receiver into a voltage signal.

[0018] The input terminal of the analog-to-digital converter module is connected to the output terminal of the current-to-voltage conversion circuit. The analog-to-digital converter module converts the voltage signal into a digital value representing the diameter of the cylindrical fertilizer stream.

[0019] The input of the data processing module is connected to the output of the analog-to-digital conversion module. The data processing module determines the flow rate of the granular fertilizer according to the preset calculation model.

[0020] In some embodiments, the granular fertilizer flow detection sensor further includes a cylindrical transparent window;

[0021] A circular transparent window is set on the inner wall of the stable section of the circular tube to isolate the fertilizer flow from the light emitter, and to isolate the fertilizer flow from the light receiver.

[0022] In some embodiments, the light emitter is an infrared light emitter; the light receiver is an infrared light receiver;

[0023] or,

[0024] The optical transmitter is a laser transmitter; the optical receiver is a laser receiver.

[0025] or,

[0026] The optical transmitter is an optical fiber transmitter; the optical receiver is an optical fiber receiver.

[0027] In some embodiments, a display is also included;

[0028] The display is connected to the data processing module and is used to display the flow rate of the granular fertilizer.

[0029] In some embodiments, the computational model is as follows:

[0030]

[0031] Where M is the mass of granular fertilizer flowing out per unit sampling time, ρ is the density of granular fertilizer, D is the diameter of the cylindrical fertilizer flow, h is the distance the granular fertilizer flows per unit sampling time, and ε is the porosity of the cylindrical fertilizer flow.

[0032] In some embodiments, the air inlet is an annular slit.

[0033] In some embodiments, the air inlet is a plurality of micropores arranged in a ring.

[0034] In some embodiments, a fan is also included.

[0035] The present invention also provides a fertilizer applicator, including the granular fertilizer flow detection device described in any of the above embodiments.

[0036] The granular fertilizer flow detection device provided by the present invention forms a stable cylindrical fertilizer flow by setting an airflow assist device, making the granular fertilizer flow detected by the granular fertilizer flow detection sensor more accurate. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the structure of the airflow-assisted granular fertilizer flow photoelectric monitoring system provided by the present invention.

[0039] Figure 2 This is a schematic diagram of the structure of the fertilizer excretion monomer provided by the present invention.

[0040] Figure 3 This is a schematic diagram of the structure of the granular fertilizer flow detection sensor provided by the present invention.

[0041] Figure 4 This is a schematic diagram illustrating the working principle of the airflow assist device provided by the present invention.

[0042] Figure 5 This is a schematic diagram of the light flux detection principle provided by the present invention.

[0043] Figure 6 This is a schematic diagram of the signal processing flow provided by the present invention. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0045] Figure 1 This is a schematic diagram of the airflow-assisted granular fertilizer flow photoelectric monitoring system provided by the present invention, as shown below. Figure 1 As shown, the airflow-assisted granular fertilizer flow photoelectric monitoring system provided by the present invention includes a fan 1, a fertilizer discharge unit 2, an airflow assist device 3, a photoelectric granular fertilizer flow detection sensor 4, a signal processing module 5, a data acquisition module 6, and a smart terminal 7. The fan generates a stable positive pressure airflow, which enters the airflow assist device's inlet through a polyurethane (PU) airflow hose from the fan outlet. The fertilizer discharge unit discharges fertilizer from the fertilizer tank at a certain flow rate according to preset parameters. The photoelectric granular fertilizer flow detection sensor is installed in the stable airflow area of ​​the airflow assist device. When fertilizer passes through the detection area, the granular fertilizer flow sensor generates a corresponding electrical signal based on the number of granules. These electrical signals are received by the signal processing module, amplified, and filtered to form a voltage signal that can be received by the data acquisition module. The data acquisition module is responsible for digitizing the acquired voltage signal and transmitting the processed data to the smart terminal via CAN communication. The smart terminal displays key information such as fertilizer discharge flow rate and discharge status.

[0046] Figure 2 This is a schematic diagram of the structure of the fertilizer excretion monomer provided by the present invention, as shown below. Figure 2As shown, the entire fertilizer discharge unit mainly consists of a fertilizer tank 8, a fertilizer discharge baffle 9, an outer grooved wheel 10, a fertilizer discharger housing 11, an outer grooved wheel baffle 12, an airflow auxiliary device 13, and a photoelectric granular fertilizer flow detection sensor 14. Driven by a motor or hydraulic motor, granular fertilizer is discharged from the fertilizer tank through the outer grooved wheel fertilizer discharger. The opening of the fertilizer discharge baffle and the rotation speed of the outer grooved wheel can adjust the discharge volume. The granular fertilizer enters the airflow auxiliary device. During this process, the originally scattered and disordered fertilizer forms a cylindrical fertilizer flow in the central area of ​​the fertilizer pipe under the action of the annular airflow, ensuring the uniformity of fertilizer during transportation. Next, the fertilizer flow enters the detection area of ​​the photoelectric granular fertilizer flow detection sensor. The fertilizer will block the light, causing a change in light intensity. The larger the granular fertilizer flow, the more light is blocked, which means that the light flux received by the receiving end is smaller, and the photocurrent generated is also smaller. The photoelectric granular fertilizer flow detection sensor can accurately measure the flow rate of granular fertilizer in this way.

[0047] Figure 3 This is a schematic diagram of the structure of the granular fertilizer flow detection sensor provided by the present invention, as shown below. Figure 3 As shown, it mainly includes a photoelectric transmitter housing 15, a photoelectric transmitter 16, protective covers 17 and 20, a sensor housing 18, a transparent window 19, a photoelectric receiver 21, and a photoelectric receiver housing 22.

[0048] In some embodiments, the photoelectric transmitter consists of six infrared light-emitting diodes connected in parallel, with each light-emitting diode connected in series with a current-limiting resistor to ensure that the current of the infrared transmitter remains consistent. The photoelectric receiver consists of six photodetector diodes connected in parallel to improve the sensitivity of the receiver.

[0049] In some embodiments, the photoelectric transmitter can also be a laser transmitter, and the corresponding photoelectric receiver can be a laser receiver.

[0050] The photoelectric transmitter and receiver are encased and fixed by a protective cover and shell, and the inside is potted with epoxy resin black AB glue. The transmitter and receiver of the entire sensor are embedded in both ends of the sensor shell. Infrared light is emitted from the transmitter through a transparent window and granular fertilizer flow. The transparent window is made of high-transparency PVC board (0.5mm thick) and attached to the inner wall of the sensor. Finally, the infrared light is received by the photoelectric receiver to generate a photoelectric signal.

[0051] Figure 4 This is a schematic diagram illustrating the working principle of the airflow assist device provided by the present invention, as shown below. Figure 4As shown, the airflow assist device is installed on the lower fertilizer inlet and fertilizer pipe of the fertilizer dispenser (wherein, the fertilizer inlet 23 is connected to the lower fertilizer inlet of the fertilizer dispenser, and the fertilizer outlet 30 is connected to the fertilizer pipe). The guide section consists of an air inlet 24, a shell, a reducing pipe 26, and an air guide port 27 (annular air gap or multiple micropores arranged in a ring). The upper end of the reducing pipe is connected to the fertilizer inlet, and the lower end of the reducing pipe is connected to the upper end of the converging section. The diameter of the upper end of the reducing pipe is larger than the diameter of the lower end. The air guide port is located at the connection between the lower end of the reducing pipe and the upper end of the converging section.

[0052] An air inlet 24 is connected to a matching fan, which continuously provides a stable airflow at a certain air pressure. After entering the upper air chamber 25 from the air inlet, the airflow first fills the entire air chamber 25 and finally enters the fertilizer pipe through the air guide. The granular fertilizer 29 discharged from the fertilizer discharger falls along the central area when passing through the reducing pipe 26. At the same time, the airflow from the air guide 27 acts on the granular fertilizer, causing it to further converge towards the central area in the converging section / zone (I). Finally, a cylindrical fertilizer flow is formed in the airflow stabilization section / zone (II). The photoelectric granular fertilizer flow detection sensor detects this flow at this point. As the granular fertilizer flow changes, the equivalent diameter of the formed cylindrical fertilizer flow also changes accordingly, resulting in different degrees of obstruction to the photoelectric sensor, which in turn affects the light flux received by the photoelectric sensor and generates different electrical signals. Finally, the fertilizer flow leaves the stabilization area and enters the dispersion section / zone (III), where the airflow velocity decreases and the granular fertilizer begins to disperse. In addition, a guide plate 28 can be installed at the lower end (end) of the reducing pipe 26 to guide the granular fertilizer.

[0053] Figure 5 This is a schematic diagram of the light flux detection principle provided by the present invention, as shown below. Figure 5 As shown, this invention utilizes the photoelectric effect principle in photoelectric detection. Infrared light emitter 31 emits infrared light 32, which illuminates the granular fertilizer 33. Part of the light 37 is blocked by the granular fertilizer, while the unblocked light 36 illuminates the photoelectric sensor. The photoelectric receiver 35 generates a photocurrent, the magnitude of which is proportional to the intensity of the light received at the receiver. The photoelectric sensor detects the fertilizer flow reconstructed by the airflow assist device. Within a fixed sampling time, the fertilizer flow can be considered as a cylinder with height h and equivalent diameter D. An increase in fertilizer flow rate leads to an increase in the equivalent diameter D of the granular flow. The amount of fertilizer applied within a unit sampling time is calculated using the following formula to obtain the corresponding mass of granular fertilizer:

[0054]

[0055] Where M is the mass of granular fertilizer flowing out per unit sampling time, ρ is the density of granular fertilizer, D is the diameter of the cylindrical fertilizer flow, h is the distance the granular fertilizer flows per unit sampling time, and ε is the porosity of the cylindrical fertilizer flow.

[0056] Figure 6 This is a schematic diagram of the signal processing flow provided by the present invention, such as... Figure 6 As shown, the receiving end of the granular fertilizer flow detection sensor consists of multiple photodiodes connected in parallel, each in a reverse bias state. When a photodiode receives light energy, it generates a photocurrent. This photocurrent passes through a pre-amplifier current-to-voltage (I / V) converter circuit, converting the reverse current into a forward voltage signal. The voltage is then amplified by a post-amplifier voltage amplifier. A voltage follower is integrated into the data acquisition circuit to improve the circuit's ability to drive the load. The processed voltage signal is digitized by an analog-to-digital (A / D) converter and transmitted to a data processing module (microcontroller) for further processing. Finally, the fertilizer application information is sent to the terminal device for display via CAN communication.

[0057] This invention presents an airflow-assisted device that uses positive pressure airflow to reconstruct granular fertilizer into a cylindrical flow located at the center of the fertilizer tube, thereby significantly improving the uniformity of fertilizer distribution. This improvement not only enhances the measurement accuracy of the photoelectric detection sensor but also effectively reduces the contact between the fertilizer and the inner wall of the fertilizer tube, lowering the risk of blockage.

[0058] In addition, a photoelectric granular fertilizer flow rate detection method based on the principle of light flux reflects changes in granular fertilizer flow rate in real time by monitoring changes in photocurrent generated by a photoelectric sensor. Through experiments, a data conversion model between photoelectric signals and granular fertilizer flow rate was constructed, thereby achieving accurate detection of granular fertilizer flow rate.

[0059] Compared to existing solutions, which often rely on mechanical vibration or gravity conveying, fertilizer particles are prone to disordered movement and uneven distribution in the detection area, thus affecting detection accuracy. The annular gap airflow auxiliary device can better control the movement of fertilizer particles, making the fertilizer flow form a more stable cylindrical shape. This not only helps improve the detection accuracy of photoelectric sensors, but also reduces the risk of fertilizer blockage.

[0060] The granular fertilizer flow rate detection method based on the principle of light flux provided by this invention differs from the photoelectric pulse counting method. This invention reconstructs the fertilizer flow using an airflow-assisted device. Utilizing the principle of light flux, it experimentally determines the linear relationship between the photoelectric sensor response voltage and the equivalent diameter of the granular fertilizer flow, establishing a data conversion model between photoelectric signals and granular fertilizer flow rate. This invention is applicable to applications of large-flow granular fertilizer, solving the problem of real-time detection of large-flow granular fertilizer using traditional methods.

[0061] By establishing detection models for various fertilizers, this invention can be applied to the flow detection of various granular fertilizers. This means that there is no need for a complicated fertilizer calibration process before fertilization. Simply input the corresponding fertilizer type and fertilizer density into the monitoring system to achieve rapid and accurate detection, which greatly simplifies the operation process and improves work efficiency.

[0062] The present invention also provides a fertilizer applicator, including the granular fertilizer flow detection device described in any of the above embodiments.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A granular fertilizer flow detection device, characterized by, The application relates to a granular fertilizer flow detection device. The air flow assisting device is in a circular tube shape and sequentially comprises an inlet, a flow guiding section, a converging section and a stabilizing section from top to bottom. The inlet is connected with an outlet of a fertilizer discharger. The flow guiding section comprises an air inlet, a shell, a variable-diameter pipe and an air guiding outlet. The air inlet is connected with an outlet of a fan. The air flow enters a gas cavity between the variable-diameter pipe and the shell from the air inlet and is discharged from the air guiding outlet. The granular fertilizer flows out of the lower end of the variable-diameter pipe, is gradually converged in the converging section under the action of the air flow discharged from the air guiding outlet and forms a stable cylindrical fertilizer flow in the stabilizing section. The granular fertilizer flow detection sensor is arranged in the stabilizing section and detects the real-time flow of the granular fertilizer flow.

2. The granular fertilizer flow detection device of claim 1, wherein The granular fertilizer flow detection sensor comprises a light emitter, a light receiver, a current-voltage conversion circuit, an analog-digital conversion module and a data processing module. The light emitter and the light receiver are arranged on two sides of the stabilizing section. The light emitted by the light emitter is blocked by the cylindrical fertilizer flow, and the remaining light is received by the light receiver, so that the light receiver generates a current signal corresponding to the diameter of the cylindrical fertilizer flow. The input end of the current-voltage conversion circuit is connected with the output end of the light receiver. The input end of the analog-digital conversion module is connected with the output end of the current-voltage conversion circuit. The input end of the data processing module is connected with the output end of the analog-digital conversion module.

3. The granular fertilizer flow detection device of claim 2, wherein The granular fertilizer flow detection sensor further comprises a circular tube-shaped transparent window. The circular tube-shaped transparent window is arranged on the inner wall of the stabilizing section and is used for isolating the fertilizer flow from the light emitter and the light receiver.

4. The granular fertilizer flow detection apparatus of claim 2, wherein The light emitter is an infrared light emitter, and the light receiver is an infrared light receiver. Alternatively, the light emitter is a laser emitter, and the light receiver is a laser receiver. Alternatively, the light emitter is a fiber emitter, and the light receiver is a fiber receiver. The device further comprises a display. The display is connected with the data processing module and is used for displaying the flow of the granular fertilizer.

5. The granular fertilizer flow detection apparatus of claim 2, wherein The calculation model is as follows. The air guiding outlet is a ring-shaped gap.

6. The granular fertilizer flow detection apparatus of claim 2, wherein The air guiding outlet is a plurality of ring-shaped micro-holes. wherein, is the mass of granular fertilizer flowing out in a unit sampling time, is the density of the granular fertilizer, is the diameter of the cylindrical fertilizer flow, is the distance traveled by the granular fertilizer flow in a unit sampling time, is the void fraction of the cylindrical fertilizer flow.

7. The granular fertilizer flow detection apparatus of claim 1, wherein The device further comprises a fan.

8. The granular fertilizer flow detection apparatus of claim 1, wherein The device comprises the granular fertilizer flow detection device according to any one of claims 1 to 9.

9. The granular fertilizer flow detection apparatus of claim 1, wherein, ​ 10. A fertilizer applicator characterized by, ​

Images