Small paddy field intelligent weeding machine and weeding method thereof

Abstract

The invention relates to a small paddy field intelligent weeding machine and a weeding method thereof. The small paddy field intelligent weeding machine comprises a satellite navigation system, a master control box, a three-wheel type chassis, a rice row guide device, a rice seedling robustness evaluation device, a weeding and detection integrated plant protection device and a pressing and swinging device. The satellite navigation system and the main control box are mounted above the three-wheel type chassis, and the rice row guide device for detecting the transverse position of rice seedlings, the rice seedling robustness evaluation device, the removal and detection integrated plant protection device and the pressing and swinging device are sequentially mounted below the three-wheel type chassis from front to back; the removing and detecting integrated plant protection device inclines from the front upper part to the rear lower part, and the pressing and swinging device presses the inclined part above the inclined part or further presses the inclined part downwards, so that the removing and detecting integrated plant protection device enters a seedling protection mode or a weeding mode; the three-wheel type chassis adopts a front wheel driving mode to realize steering or straight movement through differential control of a pair of driving wheels. According to the invention, high-quality mechanical weed control in the rice field is realized, and the seedling damage rate is reduced.

Description

Technical Field

[0001] This invention relates to the field of mechanical weeding in paddy fields, specifically to a small-scale intelligent weeding machine for paddy fields and its weeding method. Background Technology

[0002] As a major global food crop, weed control is crucial in rice production. Traditional manual weeding methods are labor-intensive and inefficient, and with rising rural labor shortages and costs, they are no longer sufficient to meet the needs of modern agriculture. While chemical weeding is more efficient, long-term use can lead to increased weed resistance, environmental pollution, and pesticide residues in rice, which does not meet the requirements of green agriculture and sustainable development.

[0003] Mechanical weeding has received widespread attention in recent years as an environmentally friendly alternative. However, existing mechanical weeding equipment for paddy fields generally suffers from key problems such as low level of intelligence, poor adaptability, insufficient precision, and limited functionality.

[0004] Low level of intelligence is reflected in the reliance on preset paths or manual operation, making it difficult to achieve accurate autonomous navigation and inter-row operation in complex paddy field environments such as irregular seedlings and curved field ridges, resulting in missed removal or damage to seedlings.

[0005] Poor adaptability manifests as a lack of real-time perception of the growth status of rice seedlings, such as their density and vigor, making it impossible to dynamically adjust operational parameters such as travel speed, weeding depth and intensity, resulting in unstable weeding effects and easy damage in areas with weak seedlings.

[0006] The lack of precision is due to the fact that existing mechanical weeding components (such as fixed teeth and rotary blades) have difficulty effectively distinguishing between rice seedlings and weeds when working close to rice seedlings, or their accuracy is limited in complex soil environments, resulting in a high rate of seedling damage and making it difficult to achieve true "protecting seedlings while weeding".

[0007] Single function means that weeding and seedling monitoring are separated, making it impossible to form a closed-loop control and accurate operation decision based on real-time monitoring data.

[0008] Therefore, there is an urgent need in this field to develop a small paddy field weeding machine that is intelligent, can navigate autonomously, sense seedling conditions in real time, and dynamically and precisely control weeding operations accordingly, in order to overcome the shortcomings of existing technologies, effectively improve the efficiency and quality of mechanical weeding, reduce damage to rice seedlings, and promote green and efficient production in paddy fields. Summary of the Invention

[0009] To address the technical problems existing in the prior art, the purpose of this invention is to provide a small-scale intelligent weeding machine for paddy fields and its weeding method, which uses tactile sensing to perceive rice seedling information and adaptively adjusts the weeding intensity, thereby achieving the function of protecting seedlings and removing weeds in paddy fields.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A small-scale intelligent weeding machine for paddy fields includes a satellite navigation system, a central control box, a three-wheeled chassis, a rice row guiding device, a rice seedling health assessment device, an integrated weeding and detection plant protection device, and a pressure and swing device. The satellite navigation system and the central control box are installed on top of the three-wheeled chassis. The rice row guiding device, the rice seedling health assessment device, the integrated weeding and detection plant protection device, and the pressure and swing device are installed sequentially from front to back below the three-wheeled chassis. The integrated weeding and detection plant protection device tilts from the front top to the rear bottom, and the pressure and swing device presses down on the tilted part above or further presses down on the tilted part, thereby putting the integrated weeding and detection plant protection device into seedling protection mode or weeding mode. The three-wheeled chassis adopts a front-wheel drive mode, with a pair of independently driven drive wheels at the front and a driven wheel at the rear. Steering or straight-line movement is achieved through differential control of the pair of drive wheels.

[0012] As a preferred embodiment, the number of rice row guiding devices is two sets, symmetrically arranged on the left and right; the number of rice seedling vigor assessment devices is two sets, symmetrically arranged on the left and right; the number of integrated plant protection devices and pressure swing devices is one set each; the distance between the ends of the rice seedling vigor assessment devices and the integrated plant protection devices is an integer multiple of the longitudinal standard plant spacing of the rice seedlings; the rice row guiding devices, rice seedling vigor assessment devices, and pressure swing devices are all height-adjustable installations, while the integrated plant protection devices are tilt-adjustable installations.

[0013] As a preferred embodiment, the rice row guiding device includes two rice row guiding units. Each rice row guiding unit includes a slotted fixing beam, a torque-adjustable angular displacement sensor, a flexible lever, and a flexible tactile mechanism. The slotted fixing beam is vertically fixed below the three-wheeled chassis. The torque-adjustable angular displacement sensor is fixed to the adjusting slot of the slotted fixing beam. The connecting end of the flexible lever is rigidly connected to the output shaft of the torque-adjustable angular displacement sensor. The flexible tactile mechanism is tightly fitted to the front surface of the flexible lever. The main body of the flexible lever is a straight structure with an arc-shaped buckle at the end. The two flexible levers are arranged in a "V" shape and can be opened and closed by the arc-shaped buckle, with the "V" opening facing forward.

[0014] As a preferred embodiment, the flexible tactile mechanism includes a stepped force transmission component and a strain gauge flexural measuring plate. The stepped force transmission component is a flexible sheet composed of multiple layers of gradually decreasing stepped units. The thickness of each stepped unit decreases linearly from the connecting end to the end. The front surface of each stepped unit is provided with a rectangular array of micro-protrusions. The top of the micro-protrusions has a polygonal prism structure, and the height of the micro-protrusions is flush with the surface of the adjacent stepped unit. The strain gauge flexural measuring plate is attached to the rear surface of the stepped force transmission component.

[0015] As a preferred embodiment, the rice seedling vigor assessment device includes a piezoelectric thin-film sensor, a carbon fiber sheet, and a quick-reset sleeve; the carbon fiber sheet is arranged laterally, and the elongated piezoelectric thin-film sensor is located on the rear side of the carbon fiber sheet; the front side of the quick-reset sleeve is a flat surface, and the rear side is an airbag structure with multiple columns arranged sequentially along the transverse direction; the quick-reset sleeve encloses the carbon fiber sheet and the piezoelectric thin-film sensor; the cross-section of the column is a double-arc-sided triangle, and vertical grooves are formed between adjacent columns.

[0016] As a preferred embodiment, the integrated plant protection device includes a hinged beam, connecting brackets, spring-tooth components, air pipes, a pressure sensor, and a silicone sleeve. The hinged beam is fixed to a three-wheeled chassis with adjustable angle via the connecting brackets. Multiple spring-tooth components are arranged sequentially along the hinged beam, with gaps between them for rice seedlings to pass through. The silicone sleeve is fitted onto the outer surface of the working teeth at the end of each spring-tooth component. The spring-tooth components have cavities inside, and the silicone sleeve, the cavity, and the pressure sensor are connected sequentially via air pipes. The pressure sensor is fixed to the hinged beam. The outer surface of the silicone sleeve has an array of micro-protrusions to enhance stability in contact with the soil.

[0017] As a preferred embodiment, the spring tooth component includes a base component and working teeth. The base component is connected between the hinged beam and the working teeth, and the working teeth are located at the end of the base component and are parallel to the ground. The base component is a hollow tubular structure sealed at both ends, with an obtuse-angle bend above the contact area corresponding to the pressure swing device, and the end of the base component forms a solid section and forms an acute-angle bend downwards. The working teeth are used to contact the soil and are shorter than the longitudinal plant spacing. The working teeth have a wave-shaped structure, and the amplitude of the wave decreases linearly from front to back, forming a gradually contracting elastic deformation zone.

[0018] As a preferred embodiment, the pressure-swing device includes a fixed base, a brushless DC motor, a universal coupling, a right-angle steering gear, and a pressure-swing actuator. The fixed base is detachably connected to a three-wheeled chassis via fasteners. The brushless DC motor is fixed to the fixed base via shock-absorbing pads and a rigid bracket. The universal coupling connects the output shaft of the brushless DC motor and the input shaft of the right-angle steering gear. The central pivot of the pressure-swing actuator is connected to the output shaft of the right-angle steering gear via a flange, and the brushless DC motor drives the central pivot to rotate. The pressure-swing actuator includes a central pivot, a flat pressure adjustment plate, and a pressure-swing adjustment plate. The flat pressure adjustment plate and the pressure-swing adjustment plate are symmetrically cross-shaped and rotated by the central pivot. The radial width of the flat pressure adjustment plate is smaller than the radial width of the pressure-swing adjustment plate.

[0019] As a preferred embodiment, the flat pressure adjusting plate is provided with straight toothed racks with the same structure at both ends, and the pressure swing adjusting plate is provided with toothed plates with reverse inclined oblique teeth at both ends.

[0020] A weeding method for a small-scale intelligent paddy field weeding machine includes the following steps: First, manual initial adjustment of the installation positions of the rice row guiding device, rice seedling vigor assessment device, integrated weeding and detection plant protection device, and pressure and swing device; second, trial operation of the weeding machine, where the rice row guiding device judges the lateral position information of the rice seedlings through touch, the rice seedling vigor assessment device judges the vigor information of the rice seedlings through touch, and the integrated weeding and detection plant protection device detects weed information and soil conditions through touch. Based on the detected information, the installation positions of the rice row guiding device, rice seedling vigor assessment device, integrated weeding and detection plant protection device, and pressure and swing device are precisely adjusted manually; third, formal operation of the weeding machine, where the main control box controls the operation of the weeding machine according to the navigation route of the satellite navigation system, and adjusts the direction of travel in real time according to the rice row guiding device to avoid crushing the seedlings. Based on the real-time detection information, the main control box controls the pressure plate device, and the pressure and swing device controls the integrated weeding and detection plant protection device to perform seedling protection or weeding operations.

[0021] The present invention has the following advantages:

[0022] 1. It enables high-quality mechanical weed control in paddy fields, reducing the rate of seedling damage.

[0023] 2. Equipped with a satellite navigation system and a central control box, the weeder can navigate autonomously and is highly intelligent.

[0024] 3. In the rice row guiding device, the installation position of the two rice row guiding units is adjusted to adjust the angle of the "V" shape to adapt to different rice seedlings.

[0025] 4. Each stepped unit can more clearly distinguish the vibration signals generated at its location. The micro-protrusion array increases the friction when in contact with rice and concentrates the local strain and stress, which are much higher than in flat surface areas, making the vibration signals more obvious.

[0026] 5. The directional grooves formed by the vertical slots make it easier for the quick-reset sleeve to be stretched in the vertical direction. The arc-shaped structure on both sides of the vertical slots allows for rapid rebound after the external force is released, returning it to its initial state. The double-arc-sided triangle has a constant width, resulting in a smoother change in the contact area with the rice seedlings under pressure, and also serves as a limiting element.

[0027] 6. During weeding operations, the silicone sleeve provides some protection to the rice root area. It can also be used in conjunction with the rice seedling health assessment device to distinguish between the rice root area and the weeding area, so as to adjust the working area.

[0028] 7. When the pressure swing device applies an impact force downward, the stress concentrated at the obtuse angle bend will be decomposed tangentially along the pipe wall, thus avoiding stress concentration at the connection with the hinged beam.

[0029] 8. The silicone sleeve connects the air pressure sensor to achieve conduction through the air tube connection to the hollow tubular structure, thus solving the problem of air tube redundancy.

[0030] 9. The sharp-angled downward bends in the base components can help remove resistance to the forward movement of the working teeth.

[0031] 10. The wavy structure of the working teeth increases the working area while reducing the risk of damaging seedlings.

[0032] 11. In the pressure swing device, the DC brushless motor can switch between flat pressure and inclined pressure by rotating 90 degrees each time, realizing the precise control and reliable execution of high-frequency impact load in paddy field weeding operations.

[0033] 12. The pressure swing device can switch between weeding and seedling protection. At the same time, the opposite direction of the oblique teeth can increase the working area while switching, so as to improve the weeding effect. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of a small-scale intelligent weeding machine for paddy fields.

[0035] Figure 2 This is a schematic diagram of the rice row guiding device.

[0036] Figure 3 This is a schematic diagram of the structure of a rice seedling health assessment device.

[0037] Figure 4 This is a schematic diagram of the integrated plant protection device.

[0038] Figure 5 This is a schematic diagram of the pendulum pressure device.

[0039] Figure 6 This is a magnified view of a portion of the flexible tactile mechanism.

[0040] Figure 7 This is a schematic diagram of the arc-shaped clasp.

[0041] Figure 8 This is a rear-view stereoscopic view of the rice seedling health assessment device.

[0042] Figure 9 This is a side view of the pendulum device.

[0043] Figure 10 This is a diagram showing the positional relationship between the rice seedlings and the weeding machine.

[0044] Figure 11 This is a magnified view of a small protrusion on the stepped unit.

[0045] Figure 12 This is a magnified view of the flat pressure adjustment plate and the pressure swing adjustment plate.

[0046] In the diagram: 1. Satellite navigation system; 2. Central control box; 3. Three-wheeled chassis; 4. Rice row guidance device; 5. Rice seedling vigor assessment device; 6. Integrated plant protection device; 7. Pressure pendulum device; 4-1. Slotted fixed beam; 4-2. Torque adjustable angular displacement sensor; 4-3. Flexible lever; 4-4. Flexible tactile mechanism; 4-4-1. Stepped force transmission component; 4-4-2. Strain gauge flexural measuring plate; 5-1. Piezoelectric thin film sensor; 5-2. Carbon fiber thin film sensor. 5-3. Quick reset sleeve; 6-1. Hinge beam; 6-2. Connecting angle bracket; 6-3. Spring tooth component; 6-4. Air pipe; 6-5. Air pressure sensor; 6-6. Silicone sleeve; 6-3-1. Base component; 6-3-2. Working tooth; 7-1. Fixed base; 7-2. DC brushless motor; 7-3. Universal coupling; 7-4. Right angle steering gear; 7-5. Pressure swing actuator; 7-5-1. Flat pressure adjusting plate; 7-5-2. Pressure swing adjusting plate. Detailed Implementation

[0047] The present invention will now be described in further detail with reference to specific embodiments.

[0048] A small-scale intelligent weeding machine for paddy fields includes a satellite navigation system, a central control box, a three-wheeled chassis, a rice row guiding device, a rice seedling health assessment device, an integrated weeding and detection plant protection device, and a pressure and swing device. The satellite navigation system and the central control box are installed on top of the three-wheeled chassis. The rice row guiding device, the rice seedling health assessment device, the integrated weeding and detection plant protection device, and the pressure and swing device are installed sequentially from front to back below the three-wheeled chassis. The integrated weeding and detection plant protection device tilts from the front top to the rear bottom, and the pressure and swing device presses down on the tilted part above or further presses down on the tilted part, thereby putting the integrated weeding and detection plant protection device into seedling protection mode or weeding mode. The three-wheeled chassis adopts a front-wheel drive mode, with a pair of independently driven drive wheels at the front and a driven wheel at the rear. Steering or straight-line movement is achieved through differential control of the pair of drive wheels.

[0049] Two sets of rice row guiding devices are used, symmetrically arranged on the left and right; two sets of rice seedling vigor assessment devices are used, symmetrically arranged on the left and right; one set each of the integrated crop protection device and the pressure and swing device is used; the distance between the ends of the rice seedling vigor assessment device and the integrated crop protection device is an integer multiple of the standard longitudinal spacing of the rice seedlings; the rice row guiding device, rice seedling vigor assessment device, and pressure and swing device are all height-adjustable installations, while the integrated crop protection device is tilt-adjustable installation.

[0050] The rice row guidance device includes two rice row guidance units. Each rice row guidance unit includes a slotted fixed beam, a torque-adjustable angular displacement sensor, a flexible lever, and a flexible tactile mechanism. The slotted fixed beam is vertically fixed under the three-wheeled chassis. The torque-adjustable angular displacement sensor is fixed in the adjustment slot of the slotted fixed beam. The connecting end of the flexible lever is rigidly connected to the output shaft of the torque-adjustable angular displacement sensor. The flexible tactile mechanism is tightly fitted to the front surface of the flexible lever. The main body of the flexible lever is a straight structure with an arc-shaped buckle at the end. The two flexible levers are arranged in a "V" shape and can be opened and closed by the arc-shaped buckle, with the "V" opening facing forward.

[0051] In this embodiment, a symmetrically distributed V-shaped rice row guide device achieves the width coverage of rice row detection. Combined with the biomimetic flexible lever's arc-shaped hook at the end, it guides the rice plants tangentially, reducing the occurrence of lodging. In one rice row guide device, one arc-shaped hook extends from the upper section of the end of one flexible lever, and another arc-shaped hook extends from the lower section of the end of another flexible lever; the two arc-shaped hooks overlap and are staggered. The rice row guide device is mounted on the front crossbeam of a three-wheeled chassis. A torque-adjustable angular displacement sensor is fixed to the adjustment slot of the slotted fixing beam via a bolt and nut assembly. Since there are multiple adjustment slots, the height of the torque-adjustable angular displacement sensor is adjustable.

[0052] The flexible tactile mechanism includes a stepped force transmission component and a strain gauge flexural measuring plate. The stepped force transmission component is a flexible sheet composed of multiple layers of gradually decreasing stepped units. The thickness of each stepped unit decreases linearly from the connection end to the end. The front surface of each stepped unit is provided with a rectangular array of micro-protrusions. The top of the micro-protrusions has a polygonal prism structure, and the height of the micro-protrusions is flush with the surface of the adjacent stepped unit. The strain gauge flexural measuring plate is attached to the rear surface of the stepped force transmission component.

[0053] The rice seedling vigor assessment device includes a piezoelectric thin-film sensor, a carbon fiber sheet, and a quick-reset sleeve. The carbon fiber sheet is arranged horizontally, and the elongated piezoelectric thin-film sensor is located on the rear side of the carbon fiber sheet. The front side of the quick-reset sleeve is a flat surface, and the rear side is an airbag structure with multiple columns arranged horizontally in sequence. The quick-reset sleeve wraps around the carbon fiber sheet and the piezoelectric thin-film sensor. The cross-section of the column is a double-arc-sided triangle, and vertical grooves are formed between adjacent columns.

[0054] In this embodiment, Figure 8 As shown, the quick-reset sleeve 5-3 is a transparent airbag. The carbon fiber sheet 5-2 is a grid of alternating dark gray and light gray in the figure. The piezoelectric thin-film sensor 5-1 is the brown part, arranged horizontally. The combination of the carbon fiber sheet and the quick-reset sleeve serves to provide a framework that allows for rapid reset after contact.

[0055] The integrated plant protection device includes a hinged beam, connecting brackets, spring-loaded components, air hoses, a pressure sensor, and a silicone sleeve. The hinged beam is fixed to a three-wheeled chassis with adjustable angle via the connecting brackets. Multiple spring-loaded components are arranged sequentially along the hinged beam, with gaps between them for rice seedlings to pass through. The silicone sleeve is fitted onto the outer surface of the working teeth at the end of each spring-loaded component. The spring-loaded components have internal cavities. The silicone sleeve, the cavity, and the pressure sensor are connected sequentially via air hoses, and the pressure sensor is fixed to the hinged beam. The outer surface of the silicone sleeve has a micro-protrusion array to enhance stability in contact with the soil.

[0056] The spring tooth component includes a base component and working teeth. The base component is connected between the hinged beam and the working teeth. The working teeth are located at the end of the base component and are parallel to the ground. The base component is a hollow tubular structure sealed at both ends. It has an obtuse-angle bend above the contact area of ​​the pressure swing device, and the end of the base component forms a solid section and forms an acute-angle bend downwards. The working teeth are used to contact the soil and are shorter than the longitudinal plant spacing. The working teeth have a wave-shaped structure, and the amplitude of the wave decreases linearly from front to back, forming a gradually shrinking elastic deformation zone.

[0057] The pressure-swing device includes a fixed base, a brushless DC motor, a universal coupling, a right-angle steering gear, and a pressure-swing actuator. The fixed base is detachably connected to a three-wheeled chassis via fasteners. The brushless DC motor is fixed to the fixed base via shock-absorbing pads and a rigid bracket. The universal coupling connects the output shaft of the brushless DC motor and the input shaft of the right-angle steering gear. The central pivot of the pressure-swing actuator is connected to the output shaft of the right-angle steering gear via a flange, and the brushless DC motor drives the central pivot to rotate. The pressure-swing actuator includes a central pivot, a flat pressure adjustment plate, and a pressure-swing adjustment plate. The flat pressure adjustment plate and the pressure-swing adjustment plate are symmetrically cross-shaped and rotated by the central pivot. The radial width of the flat pressure adjustment plate is smaller than the radial width of the pressure-swing adjustment plate.

[0058] The flat pressure adjusting plate has straight toothed racks with the same structure at both ends, and the pressure swing adjusting plate has toothed plates with reverse inclined oblique teeth at both ends.

[0059] A weeding method for a small-scale intelligent paddy field weeding machine includes the following steps: First, manual initial adjustment of the installation positions of the rice row guiding device, rice seedling vigor assessment device, integrated weeding and detection plant protection device, and pressure and swing device; second, trial operation of the weeding machine, where the rice row guiding device judges the lateral position information of the rice seedlings through touch, the rice seedling vigor assessment device judges the vigor information of the rice seedlings through touch, and the integrated weeding and detection plant protection device detects weed information and soil conditions through touch. Based on the detected information, the installation positions of the rice row guiding device, rice seedling vigor assessment device, integrated weeding and detection plant protection device, and pressure and swing device are precisely adjusted manually; third, formal operation of the weeding machine, where the main control box controls the operation of the weeding machine according to the navigation route of the satellite navigation system, and adjusts the direction of travel in real time according to the rice row guiding device to avoid crushing the seedlings. Based on the real-time detection information, the main control box controls the pressure plate device, and the pressure and swing device controls the integrated weeding and detection plant protection device to perform seedling protection or weeding operations.

[0060] The operation method of a small-scale intelligent weeding machine for paddy fields is as follows:

[0061] The weeding machine is mainly suitable for mechanically transplanted rice (standard rice plant spacing 15cm, row spacing 30cm), and operates approximately 10-15 days after transplanting. Due to the preferential growth advantage of rice, the design utilizes the differences in root depth and growth height between rice and weeds. The weeding mechanism works by pulling and pressing down on the weeds to displace their roots and detach them from the soil, thus removing the weeds.

[0062] Before field operations, the weeder is manually placed in the rice rows for rough alignment and the positioning accuracy of the satellite navigation system 1 is checked. A map of the paddy field boundary is imported to generate a rough operating path. The "V"-shaped opening angle of the rice row guiding device 4 is adjusted (by adjusting the initial position of the output shaft of the torque-adjustable angular displacement sensor 4-2), and the measuring heights of the rice row guiding device 4 and the rice seedling health assessment device 5 are adjusted to suitable positions. The pressure swing actuator 7-5 is installed, and the flexibility of the cross-axis linkage between the pressure adjustment plate 7-5-1 and the pressure swing adjustment plate 7-5-2 is confirmed.

[0063] During field operations, when a rice plant contacts the flexible lever 4-3 of the rice row guide device, the force exerted by the rice seedling drives the flexible lever 4-3, which in turn causes the torque-adjustable angular displacement sensor 4-2 connected to it to rotate, generating a corresponding angular displacement signal. After the rice seedling passes, the torque-adjustable angular displacement sensor returns to its initial zero position, ready to detect the next rice seedling. Simultaneously, the vibrations generated when the rice seedling contacts different stepped units of the flexible tactile mechanism 4-4 are transmitted to the strain gauge bending measuring plate 4-4-2, which outputs a feedback signal characterizing the contact features. This feedback signal is used to verify the accuracy of the rotation angle measured by the torque-adjustable angular displacement sensor 4-2 in real time. By fusing the data from these two sensors, the detection accuracy of the weeder's lateral position deviation relative to the rice row can be significantly improved. The rice seedling robustness assessment device 5 determines the growth status level (strength level) of the rice seedlings in real time. Based on this level information, the system adjusts the weeder's travel speed. Simultaneously, utilizing the distance between the rice seedling vigor assessment device 5 and the silicone sleeve 6-6 (this distance is set to the standard rice seedling spacing), the air pressure sensor collects the air pressure change signal generated by the deformation of the silicone sleeve. Due to the greater hardness of the root-soil composite area, the deformation generated when the silicone sleeve comes into contact with the rice root area, and the internal air pressure reading caused by the deformation, are relatively large. In contrast, the paddy field soil has lower hardness, resulting in a smaller deformation when the silicone sleeve comes into contact with the soil area, and the internal air pressure reading caused by the deformation. Therefore, the changes in air pressure signals collected by the air pressure sensor can distinguish the rice root area and the soil area in real time during operation. Combining the data collected by the rice seedling vigor assessment device and the air pressure sensor, the system can further determine the location information of the rice seedlings in real time during operation, enabling the system to accurately determine the area to be treated (weeding area). Based on this information, the control system controls the pressure swing device 7 to drive the spring tooth component of the integrated weeding and detection plant protection device to perform the operation action, realizing adaptive control of the weeding area, thereby achieving the purpose of precise seedling protection and weeding. The working posture of the pressure pendulum device 7 determines the working mode: when it is in the flat pressure state, the spring tooth component 6-3 performs the seedling protection action to avoid damaging the rice seedlings; when it switches to the inclined pressure state, the spring tooth component 6-3 performs the weeding action.

[0064] The intelligent weeder operates autonomously via satellite navigation and a rice row guidance device. A rice seedling health assessment device monitors seedling condition in real time and adjusts its speed autonomously. The rice seedling health assessment device, the integrated weeding and detection plant protection device, and the pressure and swing device work together to dynamically adjust the weeding operation mode based on the rice seedling detection results.

[0065] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A small-scale intelligent weeding machine for paddy fields, characterized in that: The system includes a satellite navigation system, a central control box, a three-wheeled chassis, a rice row guide device, a rice seedling health assessment device, an integrated weeding and detection plant protection device, and a pressure and sway device. The satellite navigation system and central control box are mounted on top of the three-wheeled chassis. The rice row guide device, rice seedling health assessment device, integrated weeding and detection plant protection device, and pressure and sway device are installed sequentially from front to back below the three-wheeled chassis. The integrated weeding and detection plant protection device tilts from the front top to the rear bottom. The pressure and sway device presses down on the tilted part above or further presses down on the tilted part, thus putting the integrated weeding and detection plant protection device into seedling protection mode or weeding mode. The three-wheeled chassis adopts a front-wheel drive mode, with a pair of independently driven drive wheels at the front and a driven wheel at the rear. Steering or straight-line movement is achieved through differential control of the pair of drive wheels.

2. A small-scale intelligent weeding machine for paddy fields according to claim 1, characterized in that: Two sets of rice row guiding devices are used, symmetrically arranged on the left and right; two sets of rice seedling vigor assessment devices are used, symmetrically arranged on the left and right; one set each of the integrated crop protection device and the pressure and swing device is used; the distance between the ends of the rice seedling vigor assessment device and the integrated crop protection device is an integer multiple of the standard longitudinal spacing of the rice seedlings; the rice row guiding device, rice seedling vigor assessment device, and pressure and swing device are all height-adjustable installations, while the integrated crop protection device is tilt-adjustable installation.

3. A small-scale intelligent weeding machine for paddy fields according to claim 1, characterized in that: The rice row guidance device includes two rice row guidance units. Each rice row guidance unit includes a slotted fixed beam, a torque-adjustable angular displacement sensor, a flexible lever, and a flexible tactile mechanism. The slotted fixed beam is vertically fixed under the three-wheeled chassis. The torque-adjustable angular displacement sensor is fixed in the adjustment slot of the slotted fixed beam. The connecting end of the flexible lever is rigidly connected to the output shaft of the torque-adjustable angular displacement sensor. The flexible tactile mechanism is tightly fitted to the front surface of the flexible lever. The main body of the flexible lever is a straight structure with an arc-shaped buckle at the end. The two flexible levers are arranged in a "V" shape and can be opened and closed by the arc-shaped buckle, with the "V" opening facing forward.

4. A small-scale intelligent weeding machine for paddy fields according to claim 3, characterized in that: The flexible tactile mechanism includes a stepped force transmission component and a strain gauge flexural measuring plate. The stepped force transmission component is a flexible sheet composed of multiple layers of gradually decreasing stepped units. The thickness of each stepped unit decreases linearly from the connection end to the end. The front surface of each stepped unit is provided with a rectangular array of micro-protrusions. The top of the micro-protrusions has a polygonal prism structure, and the height of the micro-protrusions is flush with the surface of the adjacent stepped unit. The strain gauge flexural measuring plate is attached to the rear surface of the stepped force transmission component.

5. A small-scale intelligent weeding machine for paddy fields according to claim 1, characterized in that: The rice seedling vigor assessment device includes a piezoelectric thin-film sensor, a carbon fiber sheet, and a quick-reset sleeve. The carbon fiber sheet is arranged horizontally, and the elongated piezoelectric thin-film sensor is located on the rear side of the carbon fiber sheet. The front side of the quick-reset sleeve is a flat surface, and the rear side is an airbag structure with multiple columns arranged horizontally in sequence. The quick-reset sleeve wraps around the carbon fiber sheet and the piezoelectric thin-film sensor. The cross-section of the column is a double-arc-sided triangle, and vertical grooves are formed between adjacent columns.

6. A small-scale intelligent weeding machine for paddy fields according to claim 1, characterized in that: The integrated plant protection device includes a hinged beam, connecting brackets, spring-loaded components, air hoses, a pressure sensor, and a silicone sleeve. The hinged beam is fixed to a three-wheeled chassis with adjustable angle via the connecting brackets. Multiple spring-loaded components are arranged sequentially along the hinged beam, with gaps between them for rice seedlings to pass through. The silicone sleeve is fitted onto the outer surface of the working teeth at the end of each spring-loaded component. The spring-loaded components have internal cavities. The silicone sleeve, the cavity, and the pressure sensor are connected sequentially via air hoses, and the pressure sensor is fixed to the hinged beam. The outer surface of the silicone sleeve has a micro-protrusion array to enhance stability in contact with the soil.

7. A small-scale intelligent weeding machine for paddy fields according to claim 6, characterized in that: The spring tooth component includes a base component and working teeth. The base component is connected between the hinged beam and the working teeth. The working teeth are located at the end of the base component and are parallel to the ground. The base component is a hollow tubular structure sealed at both ends. It has an obtuse-angle bend above the contact area of ​​the pressure swing device, and the end of the base component forms a solid section and forms an acute-angle bend downwards. The working teeth are used to contact the soil and are shorter than the longitudinal plant spacing. The working teeth have a wave-shaped structure, and the amplitude of the wave decreases linearly from front to back, forming a gradually shrinking elastic deformation zone.

8. A small-scale intelligent weeding machine for paddy fields according to claim 1, characterized in that: The pressure-swing device includes a fixed base, a brushless DC motor, a universal coupling, a right-angle steering gear, and a pressure-swing actuator. The fixed base is detachably connected to a three-wheeled chassis via fasteners. The brushless DC motor is fixed to the fixed base via shock-absorbing pads and a rigid bracket. The universal coupling connects the output shaft of the brushless DC motor and the input shaft of the right-angle steering gear. The central pivot of the pressure-swing actuator is connected to the output shaft of the right-angle steering gear via a flange, and the brushless DC motor drives the central pivot to rotate. The pressure-swing actuator includes a central pivot, a flat pressure adjustment plate, and a pressure-swing adjustment plate. The flat pressure adjustment plate and the pressure-swing adjustment plate are symmetrically cross-shaped and rotated by the central pivot. The radial width of the flat pressure adjustment plate is smaller than the radial width of the pressure-swing adjustment plate.

9. A small-scale intelligent weeding machine for paddy fields according to claim 8, characterized in that: The flat pressure adjusting plate has straight toothed racks with the same structure at both ends, and the pressure swing adjusting plate has toothed plates with reverse inclined oblique teeth at both ends.

10. A weeding method for a small-scale intelligent paddy field weeding machine according to any one of claims 1 to 9, characterized in that, Includes the following steps: The installation positions of the rice row guiding device, rice seedling health assessment device, integrated plant protection device and pressure swing device are manually adjusted in the initial stage; During the trial operation of the weeding machine, the rice row guiding device judged the lateral position information of the rice seedlings through touch, the rice seedling health assessment device judged the health information of the rice seedlings through touch, and the integrated weeding and detection plant protection device detected weed information and soil conditions through touch. Based on the detected information, the installation positions of the rice row guiding device, rice seedling health assessment device, integrated weeding and detection plant protection device and pressure swing device were precisely adjusted manually. Once the weeder is in operation, the main control box controls its operation based on the navigation route of the satellite navigation system and adjusts its direction of travel in real time according to the rice row guidance device to avoid crushing the seedlings. Based on real-time detection information, the main control box controls the pressure and swing device, which in turn controls the integrated weeding and detection plant protection device to perform seedling protection or weeding operations.

Images