Clamping type pulse frequency sweeping vibration picking method

Abstract

The invention provides a clamping type pulse frequency sweeping vibration picking method which is achieved through a picking machine, the picking machine comprises a picking machine body, the picking machine body comprises a clamping device and a driving device, the clamping device comprises a moving mechanism, a movable comb bar and a fixed comb bar, the moving mechanism drives the movable comb bar to get close to or get away from the fixed comb bar, and the driving device drives the movable comb bar to move away from the fixed comb bar. The driving device comprises a driving motor, the driving motor drives the clamping device to move at different frequencies, and the method comprises the specific steps that S1, the driving motor is set to be in a pulse type operation mode; s2, the driving motor operates in a low-frequency band, and after the driving motor outputs N pulses in the low-frequency band, the driving motor stops vibrating; s3, the driving motor is switched to run in a middle frequency band, and the driving motor performs frequency sweeping in a step-by-step mode in the middle frequency band; s4, according to the swing angle of the fruit bunch, the operation state of a driving motor is adjusted, and the operation state comprises a staying state, an ascending state or a flyback state; the picking efficiency and the fruit perfectness ratio are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of agricultural picking, in particular to a clamping type pulse sweep frequency vibration picking method. BACKGROUND

[0002] At present, when picking fruit trees such as litchi, longan, olive and walnut, a vibration type picking machine is used, which mainly makes the branches or fruit stalks vibrate through mechanical vibration, so that the fruits fall off. However, in actual operation, when the existing vibration picking machine fixes the branches, a comb rod clamping method is generally used, and the spacing between the comb rods is fixedly set. This fixed spacing structure cannot deal with fruit trees with different tree shapes and different branch densities. When the spacing between the comb rods is set wide, although it can more smoothly penetrate into the inside of the fruit tree canopy, reduce the collision with the peripheral branches and leaves, and easily wrap the target branches, the wide spacing will cause the vibration energy to be excessively dispersed in the transmission process, and cannot be concentrated on the branches and fruit stalks, so that some fruits far from the vibration source cannot obtain enough vibration energy, and thus cannot be easily picked. When the spacing between the comb rods is set narrow, although it can increase the contact density of the comb rods and the branches, and make the vibration energy more concentratedly transmitted, the narrow spacing will significantly increase the resistance of the comb rods entering the canopy, and easily scratch and squeeze the tender branches, leaves and mature fruits of the fruit tree during the penetration process, which not only causes damage to the subsequent growth of the fruit tree, but also reduces the integrity and commodity value of the fruits, and seriously affects the picking quality.

[0003] In addition, the existing vibration picking machine uses a continuous single frequency excitation mode, which cannot dynamically adjust according to the difference in the natural frequency of the fruit stalks. When the excitation frequency is set too high, although it can form resonance with some fruit stalks with high natural frequency, so that they obtain enough vibration energy to realize fruit falling, for fruit stalks with low natural frequency, the high frequency will cause the vibration amplitude to be too small, and the connection force between the fruits and the fruit stalks cannot be broken, thereby causing the fruits to be retained. When the excitation frequency is set too low, although it can meet the vibration needs of fruit stalks with low natural frequency, it is difficult to make fruit stalks with high natural frequency reach the resonance state, and thus some fruits cannot be easily picked.

[0004] A kind of near fruit vibration type litchi harvesting machine is disclosed in the patent document with application number 201310139351.6, publication date 2015.05.20, and classification A01D46 / 26, including vibration picking mechanism, support mechanism, transmission mechanism and control mechanism, vibration picking mechanism is arranged at the end of support mechanism, transmission mechanism is arranged on support mechanism and is connected with vibration picking mechanism, control mechanism is electrically connected with transmission mechanism, overcome the defect that existing harvester will cause damage to fruit tree when picking, while ensuring that fruit tree is not damaged, effectively improve harvesting efficiency and reduce harvesting cost, can be well applied to large-area orchard fruit picking, in addition to be applied to litchi harvesting operation, also can be applied to picking of small fruits such as longan, its application range is wider;When harvesting using the structure, the harvested fruit is single, which can avoid subsequent stem removal operation, simplify the process and reduce labor cost.

[0005] The above document relies on the crank slider assembly to drive the sliding rod reciprocating motion to drive the vibration comb to swing left and right, so that single operation can only output a single frequency vibration, which cannot dynamically match the inherent frequency difference of different varieties of fruit trees and different maturity fruit stems, and if a single excessive vibration frequency is used for transmission, the branch is in a static state at the beginning, and small branches without fruit may be broken, causing excessive damage to the entire fruit tree;The vibration comb is arranged in a fixed structure, and the comb tooth spacing is not adjustable, so that when facing the inner layer of the dense canopy, the entering resistance is large and the unharvested fruits are easily contacted, and the branch is not clamped so that the entire branch swings without clamping point, so that the required vibration power is larger, and it is difficult to balance the comb entering property and vibration efficiency. SUMMARY

[0006] The present application provides a clamping type pulse sweep frequency vibration picking method, which easily enters the crown layer stage to clamp the fruit branch, and then drives the comb rod to vibrate at different frequencies, improving picking efficiency and fruit integrity.

[0007] To achieve the above purpose, the technical scheme of the present application is as follows: a clamping type pulse sweep frequency vibration picking method is realized by a picking machine, the picking machine includes a picking machine body, a clamping device and a driving device, the clamping device includes a moving mechanism, a movable comb rod and a fixed comb rod, the moving mechanism drives the movable comb rod to approach or move away from the fixed comb rod, and the driving device includes a driving motor, the driving motor drives the clamping device to move at different frequencies, and the specific steps include: S1 driving motor is set to pulse operation mode; S2 the driving motor operates in a low frequency band, and the driving motor stops vibrating when the driving motor outputs N pulses in the low frequency band; The S3 drive motor switches to the mid-frequency band and sweeps the frequency in segments in a stepping manner within this mid-frequency band, continuously outputting N pulses in each segment; S4 determines the current swing angle of the fruit bunch, the swing angle gain of adjacent segments, and the fruit drop situation. Based on the current swing angle, the swing angle gain of adjacent segments, and the fruit drop situation, it adjusts the operating state of the drive motor 41. The operating state includes the dwell, ascending, or retrace states. The S5 drive motor operates in the adjusted running state until the fruit drop meets the preset requirements.

[0008] The above configuration uses a combination of a moving comb, a fixed comb, and a moving mechanism. The moving mechanism can drive the moving comb to move closer to or further away from the fixed comb, achieving wide-space entry and narrow-space vibration between the combs. The wide-space state can reduce interference between the comb and the branches and leaves, easily penetrating the fruit tree canopy. The narrow-space state can enhance the contact stiffness between the comb and the fruit branches, greatly improving the vibration energy transmission efficiency. Step S1 sets the motor to pulse mode, which, in conjunction with step S2, outputs N pulses in the low-frequency band and then stops oscillating. This not only establishes the initial oscillation of the fruit bunch through the low-frequency pulses, but also allows the fruit bunch to oscillate due to inertia during the oscillation-stopping phase in the low-frequency stage, forming phase superposition with the pulses in the subsequent step S3, thus reducing ineffective energy consumption. Step S3 uses a step-by-step frequency sweep in the mid-frequency band, outputting N pulses in each segment. This gradually covers the natural frequencies of different orders of the fruit bunch system, allowing fruit stems of different positions, thicknesses, and maturity levels to resonate. Step S4, based on the oscillation angle of the fruit bunch, the oscillation angle gain of adjacent segments, and the fruit drop situation, for example, when the current gain is large and the fruit drop is high... When there are many fruit drop cases, it proves that the adjusted frequency can produce good harvesting results, and you can choose to pause. Then, when the current gain is large but the fruit drop is not obvious, you can continue to increase the frequency. When the fruit drop decreases after the frequency increase, perform a sweepback operation to better match the vibration frequency of the drive motor and adjust the operating state of the drive motor. The operating state includes pause, increase, or sweepback to ensure sufficient resonance. This allows vibration at the mid-frequency to make the branches tend to break, and then the frequency increase operation further makes the branches break completely, improving harvesting efficiency and fruit integrity rate, and completely solving the problem that traditional single-frequency vibration cannot adapt to multi-frequency fruit stems and incomplete harvesting.

[0009] Furthermore, before step S1, there is also step S01, in which the moving mechanism first drives the moving comb bar away from the fixed comb bar, then moves the clamping device to the corresponding position so that the branch is located between the moving comb bar and the fixed comb bar, and then the moving mechanism drives the moving comb bar closer to the fixed comb bar.

[0010] The above settings, with the wide spacing between the moving and fixed combs, significantly reduce the probability of the combs rubbing against the outer branches and leaves during their penetration into the canopy. This avoids the damage to tender branches caused by the high resistance of traditional fixed narrow-spacing combs. Once the fruit branch is in place, the moving mechanism moves the moving comb closer to the fixed comb, and the final clamping distance can be adaptively adjusted according to the thickness of the fruit branch to ensure close contact between the comb and the fruit branch. This ensures that the comb is in stable contact with the fruit branch when the pulse vibration is started in step S1.

[0011] Furthermore, in step S2, the low-frequency band is 0-5Hz.

[0012] The above settings, in step S2, use 0-5Hz low-frequency pulse excitation to accurately match the inherent characteristics of this type of fruit stalk, so that it will generate initial resonance and oscillation first, avoiding the problem that traditional single high-frequency vibration cannot adapt to low-frequency fruit stalks, resulting in the fruit at the base being difficult to fall off.

[0013] Furthermore, in step S3, the intermediate frequency band is 5-15Hz, and the segmented frequency sweeping is to divide the intermediate frequency band into 5-8Hz, 8-11Hz and 11-15Hz segments, and increase the frequency in 1Hz increments.

[0014] The above settings divide the mid-frequency band into three sub-bands, which can more precisely cover the inherent frequency of the fruit stalk within this range. This avoids the problem of insufficient resonance of some fruit stalks due to the large frequency span and insufficient dwell time in traditional full-segment frequency sweep. At the same time, with a step accuracy of 1Hz, it can ensure that the frequency adjustment in each sub-band can accurately match the inherent frequency of different fruit stalks, allowing more fruit stalks to trigger resonance in the corresponding sub-band, laying the foundation for accelerated shedding in the subsequent high-frequency band.

[0015] Furthermore, in step S4, the sway angle of the fruit bunch relative to the vertical direction is determined. Peak swing angle adjacent frequency band swing angle gain To establish the resonant swing angle threshold, maintain the current frequency and add N pulses; when The minimum effective swing angle threshold, To achieve the minimum gain threshold, the frequency is increased in preset step frequencies; after frequency upscaling... When the relative decrease exceeds 20% compared to the previous period, the frequency is scanned back to the frequency corresponding to the historical peak swing angle.

[0016] The above settings, The resonant swing angle threshold is 20º-35º. The minimum effective swing angle threshold is 8º-12º. The minimum gain threshold is 1.15. For the gain of the swing angle in the previous stage Swing angle gain in the next stage The ratio between them, therefore when When this occurs, it indicates that the current frequency has effectively resonated with the natural frequency of the fruit stalk. At this point, maintaining the current frequency and adding N pulses will allow the resonance to continue sufficiently, ensuring that the connection force of the fruit stalk is adequately weakened. This indicates that the current frequency has not triggered effective resonance, and increasing the frequency in 1Hz increments can quickly explore a more suitable frequency range; after the frequency is increased... Compared to the previous setting of retrace to the historical peak frequency when the frequency drops by more than 20%, this avoids missing the optimal resonant frequency due to blindly increasing the frequency. By locking the frequency at which the peak swing angle was generated through the retrace mechanism, the accuracy of the resonant excitation is ensured.

[0017] Furthermore, the harvester body includes a tracked chassis, a control device, and a robotic arm. The control device and the robotic arm are mounted on the tracked chassis. The control device is electrically connected to the robotic arm, and the robotic arm and the clamping device are fixedly connected.

[0018] The above configuration includes a tracked chassis with tracks that propel the harvester body through friction between the tracks and the ground. Once the machine reaches the desired position, the control device sends an electrical signal to activate the robotic arm, which in turn moves the gripping device.

[0019] Furthermore, the clamping device also includes a clamping fixed plate and a clamping movable plate. The clamping fixed plate is fixedly connected to the robotic arm. A clamping slide rail is provided on one side of the clamping fixed plate, and two or more clamping sliders are provided on one side of the clamping movable plate. The clamping sliders are provided with clamping grooves that match the clamping slide rails, and the clamping sliders are slidably connected to the clamping slide rails through the clamping grooves. The above configuration, with the sliding connection between the clamping slide rail and the clamping slider, provides stable guidance for the movement of the clamping moving plate, ensuring that it maintains a straight trajectory as it approaches or moves away from the clamping fixed plate. Furthermore, the driving device includes a driving crank and a driving connecting rod, the driving motor is fixedly connected to the clamping fixed plate, the output shaft of the driving motor is connected to the driving crank, and the driving crank is hinged to the clamping moving plate through the driving connecting rod.

[0020] The above configuration, including the drive crank and drive connecting rod, converts the rotational motion of the drive motor into the reciprocating linear motion of the clamping moving plate. This configuration offers high transmission efficiency and a simple, reliable structure. It can also be combined with pulse sweep vibration to drive the clamping moving plate to vibrate, thereby ensuring efficient energy transfer to the fruit branches.

[0021] Furthermore, a fixed comb row is provided on one side of the clamping moving plate, and two or more fixed comb horizontal plates are provided on the fixed comb row. Fixed comb rods are evenly arranged on the fixed comb horizontal plates, and fixed comb through holes are provided between two adjacent fixed comb rods. A movable comb row is provided on the other side of the clamping movable plate. The movable comb row is provided with a movable comb horizontal plate corresponding to the fixed comb horizontal plate. Movable comb rods are evenly arranged on the movable comb horizontal plate and are arranged through the fixed comb through hole.

[0022] The above configuration, with two or more layers of horizontal comb plates on the combing rack, increases the number of combing rod positions. Combined with the evenly distributed combing rods and combing through holes, it can limit and contact the fruit branches from multiple levels, increasing the contact area between the clamping device and the fruit branches, so that the vibration energy can be transmitted to the fruit branches more fully and evenly.

[0023] The movable comb plate on the movable comb row corresponds to the fixed comb plate, and the movable comb rod passes through the through hole of the fixed comb, so that the movable comb rod and the fixed comb rod can cooperate with each other. The movable comb rod is driven to move relative to the fixed comb rod through the moving mechanism to achieve clamping or releasing of the fruit branch. Moreover, this cross-cooperation of comb rods can adapt to the clamping needs of fruit branches of different thicknesses and improve the adaptability of the device. During vibration harvesting, the movable comb rod and the fixed comb rod work together on the fruit branch to further enhance the vibration effect and help the fruit stalk fall off.

[0024] Furthermore, the moving mechanism includes a moving base, a moving motor, and a moving slider. One side of the moving base is fixedly connected to the clamping moving plate. The moving motor is fixedly connected to the moving base. The output shaft of the moving motor is provided with a moving gear. The moving slider is provided with a moving rack corresponding to the position of the moving gear. The moving gear meshes with the moving rack. The moving slider is provided with a moving groove corresponding to the position of the clamping slide rail. The moving slider is slidably connected to the clamping fixed plate through the moving groove. The upper end of the moving slider is connected to the moving comb. The moving slider is disposed between the clamping fixed plate and the clamping moving plate.

[0025] The above setup involves a moving motor driving a moving gear. Through the meshing of the gear and rack, the sliding of the moving slider can be precisely controlled, thereby driving the moving comb to move stably. This allows for precise adjustment of the distance between the moving and fixed comb bars, enabling flexible adjustment of the clamping force and spacing according to the thickness of the fruit branches. This ensures effective clamping of the fruit branches while avoiding over-clamping and damage. The gear and rack transmission features high transmission accuracy and good stability, making the movement of the moving comb bars smoother and more precise, thus ensuring stable energy transfer during vibration harvesting.

[0026] After adjusting the distance between the moving and fixed comb bars, the moving mechanism is not activated, fixing the position of the moving slider and the clamping plate. The drive motor then rotates the crank, causing the clamping plate to move linearly. Since the moving mechanism is not activated, it cannot rotate. The moving slider, positioned between the clamping plate and the clamping plate, moves linearly along with the clamping plate. This allows the clamping device to move together with the branch after clamping. The moving slider slides through a groove connected to the clamping plate, providing stable guidance and ensuring it maintains a linear trajectory. This makes the movement of the moving comb bar more precise and stable, preventing deviations in the fit between the moving and fixed comb bars due to slider slippage, which could affect clamping and vibration effects and improve the reliability and accuracy of the entire device. Attached Figure Description

[0027] Figure 1 This is a perspective view of the present invention.

[0028] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0029] Figure 3 for Figure 2 Enlarged view of section B in the middle.

[0030] Figure 4 This is a structural diagram of the clamping device in this invention, which removes the clamping moving plate.

[0031] Figure 5 This is an enlarged view of the clamping device in this invention.

[0032] Figure 6 This is another perspective view of the present invention.

[0033] Figure 7 for Figure 6 Enlarged view of point C.

[0034] Figure 8 This is a diagram illustrating the process of identifying fruit drop in the method of the present invention.

[0035] Figure 9 This is a flowchart of the present invention.

[0036] Explanation of reference numerals in the attached drawings: 1-Harvester body; 2-Crawler chassis; 3-Control device; 4-Drive device; 41-Drive motor; 42-Drive crank; 43-Drive connecting rod; 5-Clamping device; 51-Fixed comb bar; 52-Fixed comb crossbar; 521-Fixed comb through hole; 522-Fixed comb bar; 53-Moving comb bar; 54-Moving comb crossbar; 541-Moving comb bar; 55-Clamping plate; 551-Clamping slide rail; 56-Clamping moving plate; 57-Clamping slider; 571-Clamping groove; 58-Moving slider; 581-Moving rack; 6-Moving mechanism; 61-Moving seat; 62-Moving motor; 63-Moving gear; 611-Connecting plate; 7-Mechanical arm. Detailed Implementation

[0037] like Figures 1-7 As shown, a clamping-type pulse sweep frequency vibration harvester includes a harvester body 1. The harvester body 1 includes a clamping device 5 and a driving device 4. The clamping device 5 includes a moving mechanism 6, a moving comb bar 541, and a fixed comb bar 522. The moving mechanism 6 drives the moving comb bar 541 to move closer to or further away from the fixed comb bar 522. The driving device 4 includes a drive motor 41, which drives the clamping device to move at different frequencies. like Figure 1 As shown, the harvester body 1 includes a tracked chassis 2, a control device 3, and a robotic arm 7. The control device 3 and the robotic arm 7 are mounted on the tracked chassis 2. The control device 3 is electrically connected to the robotic arm 7. The robotic arm 7 is fixedly connected to the clamping device 5. The tracked chassis 2 is equipped with tracks. The harvester body 1 is propelled to move by the friction between the tracks and the ground. When the machine moves to the corresponding position, the control device 3 sends an electrical signal to make the robotic arm 7 operate. The robotic arm 7 can also drive the clamping device 5 to move. The operating principle of the tracked chassis 2, the control device 3, and the robotic arm 7 is as described in patent application number: 202422928128.6, and will not be elaborated further here.

[0038] The clamping device 5 also includes a clamping fixed plate 55 and a clamping movable plate 56. The clamping fixed plate 55 is fixedly connected to the robotic arm 7. A clamping slide rail 551 is provided on one side of the clamping fixed plate 55. Two or more clamping sliders 57 are provided on one side of the clamping movable plate 56. The clamping sliders 57 are provided with clamping grooves 571 that match the clamping slide rails 551. The clamping sliders 57 are slidably connected to the clamping slide rails 551 through the clamping grooves 571. One side of the moving mechanism 6 is fixedly connected to the clamping movable plate 56, and the driving device 4 is hinged to one end of the clamping movable plate 56.

[0039] The drive device 4 also includes a drive crank 42 and a drive connecting rod 43. The drive motor 41 is connected to the clamping fixed plate 55. The output shaft of the drive motor 41 is connected to the drive crank 42. The drive crank 42 is hinged to the clamping moving plate 56 through the drive connecting rod 43. The clamping slide rail 551 is slidably connected to the clamping slider 57 to provide stable guidance for the movement of the clamping moving plate 56. The drive crank 42 and the drive connecting rod 43 convert the rotational motion of the drive motor 41 into the reciprocating linear motion of the clamping moving plate 56. The transmission efficiency is high and the structure is simple and reliable. It can be combined with pulse sweep frequency vibration to drive the clamping moving plate 56 to vibrate, thereby ensuring that energy is efficiently transferred to the fruit branches.

[0040] A fixed comb row 51 is provided on one side of the clamping moving plate 56. Two or more fixed comb horizontal plates 52 are provided on the fixed comb row 51. Fixed comb rods 522 are evenly provided on the fixed comb horizontal plates 52. Fixed comb through holes 521 are provided between two adjacent fixed comb rods 522. On the other side of the clamping plate 56, there is a movable comb row 53. The movable comb row 53 is provided with a movable comb horizontal plate 54 corresponding to the fixed comb horizontal plate 52. Movable comb rods 541 are evenly arranged on the movable comb horizontal plate 54. The movable comb rods 541 pass through the fixed comb through hole 521 and slide within the fixed comb through hole 521. like Figure 4 and Figure 7 As shown, the moving mechanism 6 includes a moving base 61, a moving motor 62, and a moving slider 58. A connecting plate 611 is provided on one side of the moving base 61, and one side of the moving base 61 is fixedly connected to the clamping moving plate 56 via the connecting plate 611. The moving motor 62 is fixedly connected to the moving base 61. A moving gear 63 is provided on the output shaft of the moving motor 62. A moving rack 581 is provided on the moving slider 58 corresponding to the position of the moving gear 63. The moving gear 63 and the moving rack 581 are meshed. A moving groove (not shown in the figure) is provided on the side of the moving slider 58 opposite to the clamping slide rail 551. The moving slider 58 moves through the moving groove... The movable slider 58 is slidably connected to the clamping fixed plate 55 and the clamping moving plate 56. The movable slider 58 is restricted between the clamping fixed plate 55 and the clamping moving plate 56 by the clamping fixed plate 56 and the clamping moving plate 56. The upper end of the movable slider 58 is connected to the moving comb 53. Two or more fixed comb horizontal plates 52 are set on the fixed comb 51, which can increase the setting position of the fixed comb rods 522. With the evenly distributed fixed comb rods 522 and the fixed comb through holes 521, the fruit branches can be limited and contacted from multiple levels, which increases the contact area between the clamping device 5 and the fruit branches, so that the vibration energy can be transmitted to the fruit branches more fully and evenly.

[0041] The movable comb 53 is equipped with a movable comb plate 54 corresponding to the fixed comb plate 52, and a movable comb rod 541 passing through the fixed comb through hole 521, so that the movable comb rod 541 and the fixed comb rod 522 can cooperate with each other. The movable comb rod 541 is moved closer to or away from the fixed comb rod 522 by the moving mechanism 6, so as to clamp or release the fruit branches. Moreover, this cross-cooperation of comb rods can adapt to the clamping needs of fruit branches of different thicknesses and improve the adaptability of the device. During vibration harvesting, the movable comb rod 541 and the fixed comb rod 522 work together on the fruit branches to further enhance the vibration effect and help the fruit stalks fall off.

[0042] When the branches are clamped, the drive motor 41 does not work and keeps the clamping moving plate 56 in a fixed position. The moving motor 62 drives the moving gear 63 to rotate. Through the meshing transmission of the gear and rack, the sliding of the moving slider 58 can be precisely controlled, thereby driving the moving comb 53 to move stably. This allows for precise adjustment of the distance between the moving comb 541 and the fixed comb 522. The clamping force and distance can be flexibly adjusted according to the thickness of the fruit branches, ensuring effective clamping of the fruit branches while avoiding excessive clamping and damage. The gear and rack transmission has the characteristics of high transmission accuracy and good stability, which makes the movement of the moving comb 541 more stable and precise, providing a guarantee for the stable transmission of energy during vibration harvesting.

[0043] After clamping the branch, the clamping device 5 causes the clamped branch to swing together. The moving mechanism keeps the moving slider 58 fixed in the same position. The drive motor 41 drives the drive crank 42 to rotate and causes the drive connecting rod 43 to swing. The swing of the drive connecting rod 43 causes the clamping moving plate 56 to slide on the clamping slide rail 551. Since the moving slider 58 is fixed by the moving mechanism 6, the relative position of the moving slider 58 and the moving mechanism is fixed. Under the drive of the drive connecting rod 43, the clamping fixed plate 56 drives the moving mechanism 6 and the moving slider 58 to reciprocate together, thereby realizing the swinging of the branch. The moving slider 58 is slidably connected to the clamping fixed plate 55 through the moving groove, which provides a stable guide for the movement of the moving slider 58 and ensures that the moving slider 58 maintains a straight trajectory during the sliding process. This makes the movement of the moving comb 541 more accurate and stable, and avoids the deviation of the moving comb 541 and the fixed comb 522 due to the sliding deviation of the slider, which would affect the clamping and vibration effect and improve the reliability and accuracy of the entire device.

[0044] like Figure 9 As shown, the working method of the harvester includes the following steps: S1 drive motor 41 is set to pulse operation mode; S2 drives motor 41 to operate in the low-frequency range. After the drive motor 41 outputs N pulses in the low-frequency range, the drive motor stops vibrating. S3 drives motor 41 to switch to mid-frequency operation, and drives motor 41 sweeps frequency in segments in a stepping manner in the mid-frequency range, continuously outputting N pulses in each segment; S4 determines the current swing angle of the fruit bunch, the swing angle gain of adjacent segments, and the fruit drop situation. Based on the current swing angle, the swing angle gain of adjacent segments, and the fruit drop situation, it adjusts the operating state of the drive motor 41. The operating state includes the dwell, ascending, or retrace states. After S5 drives motor 41 to run in the adjusted operating state, it re-enters step S4 until the fruit drop meets the preset requirements.

[0045] Before step S1, there is also step S01. The moving mechanism 6 first moves the movable comb 541 away from the fixed comb 522, and then moves the clamping device 5 to the corresponding position so that the branch of the fruit branch is located between the movable comb 541 and the fixed comb 522. Then the moving mechanism 6 moves the movable comb 541 closer to the fixed comb 522. The wide spacing between the movable comb 541 and the fixed comb 522 can greatly reduce the probability of the comb stick scratching the outer branches and leaves during the process of penetrating the canopy. It avoids the damage to tender branches caused by the large entry resistance of the traditional fixed narrow spacing comb stick. After the fruit branch is in place, the moving mechanism 6 moves the movable comb 541 closer to the fixed comb 522. The final clamping distance can be adaptively adjusted according to the thickness of the fruit branch to ensure that the comb stick and the fruit branch are in close contact. It ensures that the comb stick is in stable contact with the fruit branch when the pulse vibration is started in step S1.

[0046] In step S2, the low-frequency range is 0-5Hz, where Hz is an abbreviation for Hertz. Step S2 uses 0-5Hz low-frequency pulse excitation to accurately match the inherent characteristics of this type of fruit branch, causing it to generate initial resonant oscillation first. This avoids the problem of traditional single high-frequency vibration being unable to adapt to low-frequency fruit stalks, resulting in the fruit at the base being difficult to fall off.

[0047] In step S3, the mid-frequency band is 5-15Hz. Segmented frequency sweeping divides the mid-frequency band into 5-8Hz, 8-11Hz, and 11-15Hz segments, increasing the frequency in 1Hz increments. This division of the mid-frequency band into three sub-bands allows for more precise coverage of the inherent frequencies of the fruit stalks within this range, avoiding the problem of insufficient resonance in some fruit stalks caused by the large frequency span and insufficient dwell time in traditional full-segment frequency sweeping. At the same time, the 1Hz step precision ensures that the frequency adjustment within each sub-band accurately matches the inherent frequencies of different fruit stalks, allowing more fruit branches to resonate within their corresponding sub-bands, laying the foundation for accelerated shedding in the subsequent high-frequency bands.

[0048] In step S4, the fruit cluster is determined. The angle of the fruit bunch relative to the vertical direction. The peak value of the swing angle. For adjacent frequency band swing angle gain; when To establish the resonant swing angle threshold, maintain the current frequency and add N pulses; when The minimum effective swing angle threshold, When the minimum gain threshold is reached, the frequency is increased in 1Hz increments; after frequency upsampling... When the fruit decline rate exceeds 20% compared to before the frequency was increased, the frequency was scanned back to the historical peak frequency.

[0049] like Figure 8 As shown, in this embodiment, the fruit bunch is determined by image recognition. , A binocular camera is used to image the clamping area and the fruit drop path below it. In this embodiment, the binocular camera can be set on the clamping plate 55 of the clamping device. The control device establishes a stable region of interest (ROI) a with the clamping point as the anchor. By fitting the principal axis O of the fruit bunch image segmentation result, the swing angle of the fruit bunch relative to the vertical direction is obtained. And calculate the peak swing angle within the sliding window. Swing angle gain of adjacent segments Peak swing angle This refers to the maximum value of multiple swing angles on a block b1 within the region of interest, and the swing angle gain of adjacent segments. This is the ratio of the peak swing angles of adjacent segments b1 and b2 within the region of interest. The fruit drop calculation process is as follows: when a target is detected to be moving simply downward within the region of interest and the pixel speed exceeds the threshold and passes the shape consistency judgment, a fruit drop event flag is set. Then, the ratio of the number of fruit drop event flags to the sum of the actual number of fruits identified and the number of fruit drop event flags is calculated to determine the fruit drop rate, which in turn determines the fruit drop situation.

[0050] The resonant swing angle threshold is 20º-35º. The minimum effective swing angle threshold is 8º-12º. The minimum gain threshold is 1.15. For the gain of the swing angle in the previous stage Swing angle gain in the next stage The ratio between them, therefore when When this occurs, it indicates that the current frequency has effectively resonated with the natural frequency of the fruit stalk. At this point, maintaining the current frequency and adding N pulses will allow the resonance to continue sufficiently, ensuring that the connection force of the fruit stalk is adequately weakened. This indicates that the current frequency has not triggered effective resonance, and increasing the frequency in 1Hz increments can quickly explore a more suitable frequency range; after the frequency is increased... Compared to the previous setting where the frequency drops by more than 20% and then retraces back to the resonance swing angle threshold, this avoids missing the optimal resonance frequency due to blindly increasing the frequency. By locking the frequency at which the peak swing angle was generated through the retrace mechanism, the accuracy of resonance excitation is ensured.

[0051] After S5 drives motor 41 to run in the adjusted running state, it checks again whether the fruit drop rate meets the preset fruit drop rate. In this embodiment, the preset fruit drop rate is 80%. If it meets the preset fruit drop rate, the picking stops. Otherwise, it enters step S4 again to adjust the vibration frequency until the fruit drop rate meets the preset fruit drop rate requirement and the picking stops.

[0052] The present invention uses the distance between the movable comb 541 and the fixed comb 522 to clamp the branches. The following is a comparison of the harvesting effect after clamping versus without clamping: The moving comb 541 and the fixed comb 522 are considered as the base excitations on the branches, and the moving comb 541 and the fixed comb 522 make relative displacements on the branches. The displacement of the branches is The branch is a single-degree-of-freedom mass-spring-damper. and the contact stiffness between the moving comb bar 541 and the fixed comb bar 522 Coupling. Displacement excitation of the moving comb bar 541 and the fixed comb bar 522: ; In the formula, A — Comb bar amplitude, mm; , rad / s; t — time, s.

[0053] The principle of conservation of energy, the equation of motion of the branch: ; In the formula, —Inertial force of the branches, N; To differentiate twice with respect to the resonant excitation, —Damping force of the branches, N; For the first derivative with respect to the resonant excitation, —The elasticity of the branches, N; —The difference between the elasticity of the comb and the branch.

[0054] Sorted as: ; The above equation represents a forced single-degree-of-freedom system, with the forced term derived from... .

[0055] Steady-state resonant response Displacement excitation .

[0056] Substitute and solve for the complex amplitude in the frequency domain. : ; Therefore, the amplitude of the branch displacement is ; The force transmitted to the branch can be taken as the branch's own elastic force. .

[0057] Therefore, the amplitude of the transmitted force is: ; Write the denominator as a complex impedance That is, the above formula is: ; like (If the distance is too large, the contact is weak), then the molecule → 0, therefore This illustrates that even large displacements alone are insufficient to transfer force to the branches. If (The comb rigidly clamps the branch), and the main term in the denominator becomes... Therefore, the comb and the branch vibrate almost in unison, and the branch senses the close proximity. The force. Therefore, it increases. (That is, reducing the spacing and increasing the contact / clamping) can significantly improve the force transmission amplitude.

[0058] The following is a proof of how the drive motor 41 can achieve frequency sweep excitation by changing its frequency at different stages: Simplify the fruit string into an n-degree-of-freedom mass-spring-damped system (mass For the i-th fruit and its short branch segment, the coupling is given by the connection between the branch and the fruit cluster. The dynamic equation of the fruit bunch vibration system is: ; Where M is the mass matrix; C is the damping matrix; and K is the stiffness matrix.

[0059] Assuming the external force is a simple harmonic excitation, that is Substituting into the equation, we get: ; then:

[0060] in, ; The acceleration amplitude of the i-th fruit is ; This formula is derived from the dynamic equation of a multi-degree-of-freedom vibration system. The result, derived through Fourier transform and steady-state response, shows that the acceleration amplitude is proportional to the square of the excitation frequency. In the frequency domain, the displacement... ,speed and acceleration They correspond to as , and Therefore, the acceleration amplitude The relationship between the displacement amplitude and the vibration amplitude is satisfied. This indicates that the acceleration amplitude is proportional to the square of the excitation frequency. Among them, The vector is selected to extract the displacement component of the i-th fruit from the system response vector; the superscript T indicates matrix transpose. Let be the frequency response function of the system, representing the amplitude-frequency relationship between the system output (fruit acceleration response) and input (external vibration force) under unit excitation; It is the amplitude-frequency function of the excitation force.

[0061] For the i-th fruit to fall off, the following condition must be met: ; in, This is the minimum acceleration threshold required for the fruit to separate from the pedicel, and this value is related to the fruit weight, pedicel stiffness, and pedicel connection force.

[0062] Whether a fruit falls off depends on the frequency, and the threshold frequency varies for different fruits. Frequency sweep excitation can make it reach the corresponding resonant frequency.

[0063] The proof process for using pulse vibration in this invention is as follows: Approximating a single fruit as a forced single-degree-of-freedom system (mass) m stiffness k Damping c Displacement excitation of branches by the comb Then the equation of motion for the particle corresponding to the fruit is: ; Let the natural angular frequency Damping ratio Damping frequency , To obtain the second derivative with respect to the displacement excitation, The solution is obtained by differentiating the displacement excitation by the first derivative: ; in, This represents the forced vibration displacement response of the system under external pulse excitation. This represents the free decay vibration displacement response of the system under no external force after the excitation ends. After a pulse excitation period ends, the total response of the system can be expressed as the superposition of the two, i.e. .

[0064] When a pulse (vibration) is in After the incentive period ends, the subsequent zero-incentive interval The system decays through free vibration: ; The initial phase is given by C, which is a preset parameter value. Each pulse ends with a free oscillation term with amplitude, the amplitude of which varies with time. Attenuation. The next pulse starts from non-zero initial conditions, so the new round of forced response will superimpose with the residual free oscillation, forming a phase continuum and a higher instantaneous peak value, which is more beneficial for harvesting.

[0065] The working principle of the present invention: The clamping device 5 is composed of a moving comb 541, a fixed comb 522 and a moving mechanism 6. The moving mechanism 6 can drive the moving comb 541 to approach or move away from the fixed comb 522, so as to realize wide-space entry and narrow-space vibration between the combs. The wide-space state can reduce the interference between the comb and the branches and leaves, and easily penetrate into the fruit tree canopy. The narrow-space state can enhance the contact density between the comb and the fruit branches, and greatly improve the vibration energy transmission efficiency. Step S1 sets the motor to pulse mode, which, in conjunction with step S2, outputs N pulses in the low-frequency band and then stops oscillating. This not only establishes the initial oscillation of the fruit bunch through the low-frequency pulses, but also allows the fruit bunch to oscillate due to inertia during the oscillation-stopping phase in the low-frequency stage, forming phase superposition with the pulses in the subsequent step S3, thus reducing ineffective energy consumption. Step S3 uses a step-by-step frequency sweep in the mid-frequency band, outputting N pulses in each segment. This gradually covers the natural frequencies of different orders of the fruit bunch system, allowing fruit stems of different positions, thicknesses, and maturity levels to resonate. Step S4, based on the oscillation angle of the fruit bunch, the oscillation angle gain of adjacent segments, and the fruit drop situation, for example, when the current gain is large and the fruit drop is high... When there are many fruit drop cases, it proves that the adjusted frequency can produce good harvesting results, and you can choose to pause. Then, when the current gain is large but the fruit drop is not obvious, you can continue to increase the frequency. When the fruit drop decreases after the frequency increase, perform a sweepback operation to better match the vibration frequency of the drive motor and adjust the operating state of the drive motor. The operating state includes pause, increase, or sweepback to ensure sufficient resonance. This allows vibration at the mid-frequency to make the branches tend to break, and then the frequency increase operation further makes the branches break completely, improving harvesting efficiency and fruit integrity rate, and completely solving the problem that traditional single-frequency vibration cannot adapt to multi-frequency fruit stems and incomplete harvesting.

Claims

1. A clamping pulse sweep frequency vibration harvesting method, implemented by a harvesting machine, the harvesting machine comprising a harvesting machine body, a clamping device, and a driving device, characterized in that: The clamping device includes a moving mechanism, a movable comb bar, and a fixed comb bar. The moving mechanism drives the movable comb bar to move closer to or further away from the fixed comb bar. The driving device includes a drive motor, which drives the clamping device to move at different frequencies. Specific steps include: S1 drive motor is set to pulse operation mode; The S2 drive motor operates in the low-frequency range. After the drive motor outputs N pulses in the low-frequency range, the drive motor stops vibrating. The S3 drive motor switches to the mid-frequency band and sweeps the frequency in segments in a stepping manner within this mid-frequency band, continuously outputting N pulses in each segment; S4 determines the current swing angle of the fruit bunch, the swing angle gain of adjacent segments, and the fruit drop situation. Based on the current swing angle, the swing angle gain of adjacent segments, and the fruit drop situation, it adjusts the operating status of the drive motor, including the dwell, ascending, or retrace states. The S5 drive motor operates in the adjusted running state until the fruit drop meets the preset requirements.

2. The clamping pulse sweep vibration harvesting method according to claim 1, characterized in that: Before step S1, there is also step S01, in which the moving mechanism first drives the moving comb bar away from the fixed comb bar, then moves the clamping device to the corresponding position so that the branch is located between the moving comb bar and the fixed comb bar, and then the moving mechanism drives the moving comb bar closer to the fixed comb bar.

3. The clamping pulse sweep vibration acquisition method according to claim 1, characterized in that: In step S2, the low-frequency band is 0-5Hz.

4. The clamping pulse sweep vibration harvesting method according to claim 1, characterized in that: The intermediate frequency band in step S3 is 5-15Hz. The segmented frequency sweeping divides the intermediate frequency band into 5-8Hz, 8-11Hz and 11-15Hz segments, increasing the frequency in 1Hz increments.

5. The clamping pulse sweep frequency vibration harvesting method according to claim 1, characterized in that: In step S4, the sway angle of the fruit bunch relative to the vertical direction is determined. Peak swing angle adjacent frequency band swing angle gain To establish the resonant swing angle threshold, maintain the current frequency and add N pulses; when The minimum effective swing angle threshold, To achieve the minimum gain threshold, the frequency is increased in preset step frequencies; after frequency upscaling... When the relative decrease exceeds 20% compared to the previous period, the frequency is scanned back to the frequency corresponding to the historical peak swing angle.

6. The clamping pulse sweep frequency vibration harvesting method according to claim 1, characterized in that: The harvester body includes a tracked chassis, a control device, and a robotic arm. The control device and the robotic arm are mounted on the tracked chassis. The control device is electrically connected to the robotic arm, and the robotic arm and the clamping device are fixedly connected.

7. The clamping pulse sweep vibration harvesting method according to claim 1, characterized in that: The clamping device further includes a fixed clamping plate and a movable clamping plate. The fixed clamping plate is fixedly connected to the robotic arm. A clamping slide rail is provided on one side of the fixed clamping plate, and two or more clamping sliders are provided on one side of the movable clamping plate. Each clamping slider is provided with a clamping groove that matches the clamping slide rail, and the clamping slider is slidably connected to the clamping slide rail through the clamping groove.

8. The clamping pulse sweep vibration harvesting method according to claim 7, characterized in that: The driving device further includes a driving crank and a driving connecting rod. The driving motor is connected to the clamping stationary plate, the output shaft of the driving motor is connected to the driving crank, and the driving crank is connected to the clamping moving plate through the driving connecting rod.

9. The clamping pulse sweep frequency vibration harvesting method according to claim 7, characterized in that: A fixed comb row is provided on one side of the clamping moving plate. Two or more fixed comb horizontal plates are provided on the fixed comb row. Fixed comb rods are evenly arranged on the fixed comb horizontal plates. Fixed comb through holes are provided between two adjacent fixed comb rods. A movable comb row is provided on the other side of the clamping movable plate. The movable comb row is provided with a movable comb horizontal plate corresponding to the fixed comb horizontal plate. Movable comb rods are evenly arranged on the movable comb horizontal plate and are arranged through the fixed comb through hole.

10. A clamping pulse sweep vibration harvesting method according to claim 7, characterized in that: The moving mechanism includes a moving base, a moving motor, and a moving slider. One side of the moving base is fixedly connected to a clamping moving plate. The moving motor is connected to the moving base. The output shaft of the moving motor is provided with a moving gear. The moving slider is provided with a moving rack corresponding to the position of the moving gear. The moving gear and the moving rack are meshed together. The moving slider is provided with a moving groove corresponding to the position of the clamping slide rail. The moving slider is slidably connected to the clamping fixed plate through the moving groove. The upper end of the moving slider is connected to a moving comb. The moving slider is disposed between the clamping fixed plate and the clamping moving plate.

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