A planting soil loosening device

Abstract

This utility model discloses a soil loosening device, belonging to the field of soil loosening technology. It solves the problems of sampling distortion caused by the superposition of thermal drift and zero drift, overcurrent protection failure or false tripping, and the inability of the soil loosener to operate continuously. It includes a soil loosener body and a current sampling circuit installed within it. The current sampling terminal of the current sampling circuit is connected to the three-phase drive circuit of the brushless DC motor in the soil loosener body, and the output terminal of the current sampling circuit is connected to the input terminal of the overcurrent protection circuit in the soil loosener body. The current sampling circuit dynamically follows and subtracts the drift error superimposed on the real current signal in real time. In this utility model, the electric soil loosener suffers from current sampling distortion and overcurrent protection failure or false tripping due to the superposition of thermal drift of the sampling resistor and zero drift of the operational amplifier. A symmetrical zero-current reference channel is added to generate a reverse temperature drift compensation voltage in real time. The drift is subtracted from the main signal by analog subtraction, ensuring reliable operation of the protection under true overload and error-free triggering under normal conditions.

Description

Technical Field

[0001] This utility model relates to the field of soil loosening technology, and in particular to a device for loosening planting soil. Background Technology

[0002] Soil loosening equipment, also known as electric soil loosening machine, is powered by a brushless DC motor, battery or photovoltaic power. It drives the cutter head or reciprocating shovel through a reducer and sprocket to break up and deeply loosen the soil. The frame is equipped with a walking motor and an adjustable handle. The depth and angle can be adjusted in real time through the handle and sprocket. It has overload protection with friction plates, built-in BMS, MCU, and soil sensor. The speed can be adjusted by a knob for forward and reverse rotation. Current / temperature / vibration are detected in real time, and the machine stops immediately if abnormality occurs. It is powered by photovoltaic power, has low noise and no emissions, and is suitable for greenhouses and hilly areas. Maintenance is simple: cleaning and lubrication after operation.

[0003] During operation, the electric soil rammer experiences thermal drift in the sampling resistor due to continuous heating of the controller, and the input misalignment of the INA188 instrumentation amplifier drifts to zero with temperature and time. The combination of these two factors causes the current sampling signal to systematically deviate from the true value. This results in the overcurrent protection circuit either failing to operate due to underestimating the current when the motor is already severely overloaded, thus burning out the power switch, or falsely triggering due to overestimating the current during normal operation, causing repeated shutdowns. Ultimately, this prevents the soil rammer from continuously completing farmland operations.

[0004] Therefore, a soil loosening device for planting is proposed to solve or alleviate the above problems. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a soil loosening device for planting.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A soil loosening device includes a soil loosening machine body and a current sampling circuit disposed therein. The current sampling terminal of the current sampling circuit is connected to the three-phase drive circuit of the brushless DC motor in the soil loosening machine body, and the output terminal of the current sampling circuit is connected to the input terminal of the overcurrent protection circuit in the soil loosening machine body. The current sampling circuit dynamically follows and deducts the drift error superimposed on the real current signal in real time.

[0007] Preferably, the current sampling circuit includes a main differential sampling module, an auxiliary reference sampling module, a temperature compensation reference module, a dynamic error compensation module, and a final output synthesis module. The detection terminal of the main differential sampling module is connected to the three-phase drive circuit of the brushless DC motor in the ripper body. The output terminal of the main differential sampling module is connected to the first input terminal of the final output synthesis module. The output terminal of the auxiliary reference sampling module is connected to the first input terminal of the temperature compensation reference module and the first input terminal of the dynamic error compensation module. The output terminal of the temperature compensation reference module is connected to the second input terminal of the dynamic error compensation module. The output terminal of the dynamic error compensation module is connected to the second input terminal of the final output synthesis module. The final output synthesis module is connected to the input terminal of the overcurrent protection circuit in the ripper body.

[0008] Preferably, the main differential sampling module includes a first INA188 instrumentation amplifier and a sampling resistor. One end of the sampling resistor is connected to the three-phase drive circuit of the brushless DC motor in the ripper body, and the other end of the sampling resistor is connected to the inverting input terminal of the first INA188 instrumentation amplifier. The non-inverting input terminal of the first INA188 instrumentation amplifier is connected to the three-phase drive circuit of the brushless DC motor in the ripper body. The first gain setting terminal and the second gain setting terminal of the first INA188 instrumentation amplifier are both connected to a first gain resistor. The output terminal of the first INA188 instrumentation amplifier serves as the output terminal of the main differential sampling module.

[0009] Preferably, the auxiliary reference sampling module includes a second INA188 instrumentation amplifier and a reference resistor. One end of the reference resistor is grounded, and the other end of the reference resistor is connected to the inverting input terminal of the second INA188 instrumentation amplifier. The non-inverting input terminal of the second INA188 instrumentation amplifier is grounded. The first gain setting terminal and the second gain setting terminal of the second INA188 instrumentation amplifier are both connected to a second gain resistor. The output terminal of the second INA188 instrumentation amplifier serves as the output terminal of the auxiliary reference sampling module.

[0010] Preferably, the temperature compensation reference module includes a REF5050 voltage reference source and a first OPA2188 operational amplifier. The voltage output terminal of the REF5050 voltage reference source is connected to the inverting input terminal of the first OPA2188 operational amplifier through a first resistor. The inverting input terminal of the first OPA2188 operational amplifier is connected to its output terminal through a second resistor. The non-inverting input terminal of the first OPA2188 operational amplifier is connected to the output terminal of the auxiliary reference sampling module. The output terminal of the first OPA2188 operational amplifier serves as the output terminal of the temperature compensation reference module. The power input terminal of the REF5050 voltage reference source is grounded, and the ground terminal of the REF5050 voltage reference source is grounded.

[0011] Preferably, the dynamic error compensation module includes a second OPA2188 operational amplifier, an ADG633 analog switch, and a holding capacitor. The non-inverting input of the second OPA2188 operational amplifier is connected to the output of the auxiliary reference sampling module, the inverting input of the second OPA2188 operational amplifier is connected to the output of the temperature compensation reference module, the inverting input of the second OPA2188 operational amplifier is connected to its output through a third resistor, the common terminal of the ADG633 analog switch is connected to the inverting input of the second OPA2188 operational amplifier, the two independent switching terminals of the ADG633 analog switch are respectively connected to one end of the holding capacitor, the enable terminal and the address terminal of the ADG633 analog switch are used to connect to an external oscillator, and the output of the second OPA2188 operational amplifier serves as the output of the dynamic error compensation module.

[0012] Preferably, the final output synthesis module includes a third OPA2188 operational amplifier. The non-inverting input of the third OPA2188 operational amplifier serves as the first input of the final output synthesis module. The non-inverting input of the third OPA2188 operational amplifier is connected to the output of the main differential sampling module. The inverting input of the third OPA2188 operational amplifier serves as the second input of the final output synthesis module. The inverting input of the third OPA2188 operational amplifier is connected to the output of the dynamic error compensation module. The inverting input of the third OPA2188 operational amplifier is connected to its output through a fourth resistor. The output of the third OPA2188 operational amplifier serves as the final output of the current sampling circuit.

[0013] This utility model has the following beneficial effects: The electric soil loosening machine of this utility model suffers from current sampling distortion and overcurrent protection failure or false tripping due to the superposition of thermal drift of the sampling resistor and zero-point drift of the operational amplifier. To address this, a symmetrical zero-current reference channel is added to generate a real-time reverse temperature drift compensation voltage. The drift is subtracted from the main signal through analog subtraction, ensuring reliable operation of the protection under true overload and error-free triggering under normal conditions. This guarantees continuous operation, ensures that the soil is effectively turned over, and completes sufficient loosening. This prevents plants from being unable to take root due to overly hard soil after planting, ensuring good quality and yield of the final harvested plants. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a block diagram of the current sampling circuit in this utility model.

[0016] In the diagram: 1. Soil loosening machine body; 2. Main differential sampling module; 3. Auxiliary reference sampling module; 4. Temperature compensation benchmark module; 5. Dynamic error compensation module; 6. Final output synthesis module. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0019] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0020] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this utility model and to simplify the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0021] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0022] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] A soil loosening device for planting, such as Figure 1 As shown, the device includes a ripper body 1 and a current sampling circuit installed therein. The current sampling terminal of the current sampling circuit is connected to the three-phase drive circuit of the brushless DC motor in the ripper body 1, and the output terminal of the current sampling circuit is connected to the input terminal of the overcurrent protection circuit in the ripper body 1. The current sampling circuit dynamically follows and deducts the drift error superimposed on the real current signal in real time.

[0024] like Figure 2 As shown, the current sampling circuit includes a main differential sampling module 2, an auxiliary reference sampling module 3, a temperature compensation reference module 4, a dynamic error compensation module 5, and a final output synthesis module 6. The detection terminal of the main differential sampling module 2 is connected to the three-phase drive circuit of the brushless DC motor in the ripper body 1. The output terminal of the main differential sampling module 2 is connected to the first input terminal of the final output synthesis module 6. The output terminal of the auxiliary reference sampling module 3 is connected to the first input terminal of the temperature compensation reference module 4 and the first input terminal of the dynamic error compensation module 5. The output terminal of the temperature compensation reference module 4 is connected to the second input terminal of the dynamic error compensation module 5. The output terminal of the dynamic error compensation module 5 is connected to the second input terminal of the final output synthesis module 6. The final output synthesis module 6 is connected to the input terminal of the overcurrent protection circuit in the ripper body 1.

[0025] The main differential sampling module 2 includes a first INA188 instrumentation amplifier and a sampling resistor. One end of the sampling resistor is connected to the three-phase drive circuit of the brushless DC motor in the ripper body 1, and the other end of the sampling resistor is connected to the inverting input terminal of the first INA188 instrumentation amplifier. The non-inverting input terminal of the first INA188 instrumentation amplifier is connected to the three-phase drive circuit of the brushless DC motor in the ripper body 1. The first gain setting terminal and the second gain setting terminal of the first INA188 instrumentation amplifier are connected to the first gain resistor. The output terminal of the first INA188 instrumentation amplifier serves as the output terminal of the main differential sampling module 2.

[0026] The auxiliary reference sampling module 3 includes a second INA188 instrumentation amplifier and a reference resistor. One end of the reference resistor is grounded, and the other end of the reference resistor is connected to the inverting input terminal of the second INA188 instrumentation amplifier. The non-inverting input terminal of the second INA188 instrumentation amplifier is grounded. The first gain setting terminal and the second gain setting terminal of the second INA188 instrumentation amplifier are connected together to a second gain resistor. The output terminal of the second INA188 instrumentation amplifier serves as the output terminal of the auxiliary reference sampling module 3.

[0027] The temperature compensation reference module 4 includes a REF5050 voltage reference source and a first OPA2188 operational amplifier. The voltage output terminal of the REF5050 voltage reference source is connected to the inverting input terminal of the first OPA2188 operational amplifier through a first resistor. The inverting input terminal of the first OPA2188 operational amplifier is connected to its output terminal through a second resistor. The non-inverting input terminal of the first OPA2188 operational amplifier is connected to the output terminal of the auxiliary reference sampling module 3. The output terminal of the first OPA2188 operational amplifier serves as the output terminal of the temperature compensation reference module 4. The power input terminal of the REF5050 voltage reference source is grounded, and the ground terminal of the REF5050 voltage reference source is grounded.

[0028] The dynamic error compensation module 5 includes a second OPA2188 operational amplifier, an ADG633 analog switch, and a holding capacitor. The non-inverting input of the second OPA2188 operational amplifier is connected to the output of the auxiliary reference sampling module 3, and the inverting input of the second OPA2188 operational amplifier is connected to the output of the temperature compensation reference module 4. The inverting input of the second OPA2188 operational amplifier is connected to its output through a third resistor. The common terminal of the ADG633 analog switch is connected to the inverting input of the second OPA2188 operational amplifier. The two independent switching terminals of the ADG633 analog switch are respectively connected to one end of the holding capacitor. The enable and address terminals of the ADG633 analog switch are used to connect to an external oscillator. The output of the second OPA2188 operational amplifier serves as the output of the dynamic error compensation module 5.

[0029] The final output synthesis module 6 includes a third OPA2188 operational amplifier. The non-inverting input of the third OPA2188 operational amplifier serves as the first input of the final output synthesis module 6. The non-inverting input of the third OPA2188 operational amplifier is connected to the output of the main differential sampling module 2. The inverting input of the third OPA2188 operational amplifier serves as the second input of the final output synthesis module 6. The inverting input of the third OPA2188 operational amplifier is connected to the output of the dynamic error compensation module 5. The inverting input of the third OPA2188 operational amplifier is connected to its output through a fourth resistor. The output of the third OPA2188 operational amplifier serves as the final output of the current sampling circuit.

[0030] During operation, electric soil rippers may experience serious problems such as overcurrent protection malfunction or false triggering due to temperature drift and zero-point drift in the current sampling circuit.

[0031] The problem is that when the ripper is engaged in continuous high-intensity operation, the internal ambient temperature of the motor controller will rise sharply, causing a significant thermal change in the resistance of the current sampling core component, the sampling resistor.

[0032] Meanwhile, the key parameters of the operational amplifier inside the instrumentation amplifier, which is responsible for signal amplification, such as input offset voltage and input offset current, will also experience slow and random zero-point drift as the temperature inside the housing fluctuates and the usage time increases.

[0033] These two physical phenomena, which are influenced by both temperature and time factors, combine to cause the current sampling circuit to output a false non-zero voltage even when the motor current is zero.

[0034] Or, when detecting the actual current, a systematic error occurs between the output voltage and the actual current value that cannot be eliminated through conventional calibration. This ultimately leads to a severe distortion of the current value read by the control system, resulting in two fault modes: either the motor is actually severely overloaded and the current far exceeds the safety threshold, but due to the negative drift of the sampling circuit, the overcurrent protection circuit cannot cut off the power supply in time, causing the power switch to burn out; or the motor is running under normal load, but due to the positive drift of the sampling circuit, it outputs a false high current signal, causing the overcurrent protection to malfunction, causing the machine to repeatedly and unnecessarily stop during normal operation.

[0035] To address this issue, an auxiliary reference channel that is completely symmetrical to the main sampling channel and operates under the same temperature environment is established to track the temperature drift trajectory in real time. The main differential sampling module 2 is responsible for acquiring the real current signal flowing through the motor drive circuit and converting it into a voltage signal. The auxiliary reference sampling module 3 uses a reference resistor of the same material and process as the main sampling resistor to generate a reference signal containing only the temperature drift component under zero current conditions. This reference signal is simultaneously fed to the temperature compensation reference module 4 and the dynamic error compensation module 5.

[0036] Temperature compensation reference module 4 uses a high-stability voltage reference source and operational amplifier circuit to compare the received reference signal with the absolute voltage reference and generate an anti-drift compensation voltage that is opposite to the temperature drift trend. This compensation voltage reflects the correction amount that the sampling system should have under the current temperature conditions.

[0037] The dynamic error compensation module 5 uses a sample-and-hold circuit composed of an analog switch and a holding capacitor to dynamically track and store the compensation voltage, and uses the switching timing controlled by an external oscillator to periodically update and maintain the latest drift compensation value.

[0038] Finally, the dynamic compensation signal is sent to the final output synthesis module 6, where it is subjected to analog subtraction with the original current signal output by the main differential sampling module 2. The drift error component is removed from the original signal in real time, and the precisely corrected current signal is output.

[0039] This continuous, real-time compensation process allows the circuit to automatically adapt to different temperature conditions. Whether the electric soil loosener is in the cold start-up phase or in a thermally stable state after prolonged high-intensity operation, it maintains the accuracy of current sampling. This ensures that the overcurrent protection function operates reliably under actual overload conditions and avoids false triggering during normal operation. It solves the system reliability problem caused by temperature drift, extends the service life of power devices, ensures the continuity and stability of farmland operations, and ensures that the soil is thoroughly loosened, resulting in a loose and permeable structure. This prevents subsequent planting from being hampered by soil compaction. This loosening operation creates favorable conditions for plant roots to spread out and for water and nutrient absorption, helping crops develop healthily throughout their growth cycle and effectively guaranteeing the quality and yield of the final harvest.

[0040] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A soil loosening device for planting, characterized in that, The system includes a ripper body (1) and a current sampling circuit disposed therein. The current sampling terminal of the current sampling circuit is connected to the three-phase drive circuit of the brushless DC motor in the ripper body (1). The output terminal of the current sampling circuit is connected to the input terminal of the overcurrent protection circuit in the ripper body (1). The current sampling circuit dynamically follows and deducts the drift error superimposed on the real current signal in real time.

2. The soil loosening equipment according to claim 1, characterized in that, The current sampling circuit includes a main differential sampling module (2), an auxiliary reference sampling module (3), a temperature compensation reference module (4), a dynamic error compensation module (5), and a final output synthesis module (6). The detection end of the main differential sampling module (2) is connected to the three-phase drive circuit of the brushless DC motor in the ripper body (1). The output end of the main differential sampling module (2) is connected to the first input end of the final output synthesis module (6). The output end of the auxiliary reference sampling module (3) is connected to the first input end of the temperature compensation reference module (4) and the first input end of the dynamic error compensation module (5). The output end of the temperature compensation reference module (4) is connected to the second input end of the dynamic error compensation module (5). The output end of the dynamic error compensation module (5) is connected to the second input end of the final output synthesis module (6). The final output synthesis module (6) is connected to the input end of the overcurrent protection circuit in the ripper body (1).

3. The soil loosening equipment according to claim 2, characterized in that, The main differential sampling module (2) includes a first INA188 instrumentation amplifier and a sampling resistor. One end of the sampling resistor is connected to the three-phase drive circuit of the brushless DC motor in the ripper body (1). The other end of the sampling resistor is connected to the inverting input terminal of the first INA188 instrumentation amplifier. The non-inverting input terminal of the first INA188 instrumentation amplifier is connected to the three-phase drive circuit of the brushless DC motor in the ripper body (1). The first gain setting terminal and the second gain setting terminal of the first INA188 instrumentation amplifier are connected to a first gain resistor. The output terminal of the first INA188 instrumentation amplifier serves as the output terminal of the main differential sampling module (2).

4. The soil loosening equipment according to claim 2, characterized in that, The auxiliary reference sampling module (3) includes a second INA188 instrumentation amplifier and a reference resistor. One end of the reference resistor is grounded, and the other end of the reference resistor is connected to the inverting input terminal of the second INA188 instrumentation amplifier. The non-inverting input terminal of the second INA188 instrumentation amplifier is grounded. The first gain setting terminal and the second gain setting terminal of the second INA188 instrumentation amplifier are connected together to a second gain resistor. The output terminal of the second INA188 instrumentation amplifier serves as the output terminal of the auxiliary reference sampling module (3).

5. The soil loosening equipment according to claim 2, characterized in that, The temperature compensation reference module (4) includes a REF5050 voltage reference source and a first OPA2188 operational amplifier. The voltage output terminal of the REF5050 voltage reference source is connected to the inverting input terminal of the first OPA2188 operational amplifier through a first resistor. The inverting input terminal of the first OPA2188 operational amplifier is connected to its output terminal through a second resistor. The non-inverting input terminal of the first OPA2188 operational amplifier is connected to the output terminal of the auxiliary reference sampling module (3). The output terminal of the first OPA2188 operational amplifier serves as the output terminal of the temperature compensation reference module (4). The power input terminal of the REF5050 voltage reference source is grounded, and the ground terminal of the REF5050 voltage reference source is grounded.

6. The soil loosening equipment according to claim 2, characterized in that, The dynamic error compensation module (5) includes a second OPA2188 operational amplifier, an ADG633 analog switch, and a holding capacitor. The non-inverting input of the second OPA2188 operational amplifier is connected to the output of the auxiliary reference sampling module (3). The inverting input of the second OPA2188 operational amplifier is connected to the output of the temperature compensation reference module (4). The inverting input of the second OPA2188 operational amplifier is connected to its output through a third resistor. The common terminal of the ADG633 analog switch is connected to the inverting input of the second OPA2188 operational amplifier. The two independent switching terminals of the ADG633 analog switch are respectively connected to one end of the holding capacitor. The enable and address terminals of the ADG633 analog switch are used to connect to an external oscillator. The output of the second OPA2188 operational amplifier serves as the output of the dynamic error compensation module (5).

7. The soil loosening equipment according to claim 2, characterized in that, The final output synthesis module (6) includes a third OPA2188 operational amplifier. The non-inverting input of the third OPA2188 operational amplifier serves as the first input of the final output synthesis module (6). The non-inverting input of the third OPA2188 operational amplifier is connected to the output of the main differential sampling module (2). The inverting input of the third OPA2188 operational amplifier serves as the second input of the final output synthesis module (6). The inverting input of the third OPA2188 operational amplifier is connected to the output of the dynamic error compensation module (5). The inverting input of the third OPA2188 operational amplifier is connected to its output through a fourth resistor. The output of the third OPA2188 operational amplifier serves as the final output of the current sampling circuit.

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