Self-balancing high-efficiency energy-saving crop harvesting device and working process thereof

Abstract

A self-balancing high-efficiency energy-saving crop harvesting device and its working process belong to the technical field of crop harvesting. The device comprises a main frame, a grabbing mechanism and a soil screening mechanism are arranged on the main frame, the soil screening mechanism is swingably arranged on the main frame and is in linkage motion with the grabbing mechanism, walking mechanisms are arranged on both sides of the main frame, and the walking mechanisms on both sides can realize independent walking and lifting motion respectively. The device can adapt to different terrains, has strong environmental adaptability, the quick-return characteristic of the crank slider mechanism is used to make the mechanical arm return efficiently, the operation continuity is improved, a single power source is used to control the linkage motion of the grabbing mechanism and the soil screening mechanism, the overall structure is more compact, the energy utilization rate is higher, and the control is more accurate, and based on the design of the conjugate cam mechanism, the crops can be placed into the box and stored and collected in the relative static state of the mechanism.

Description

Technical Field

[0001] This invention belongs to the field of crop harvesting technology, specifically relating to a self-balancing, high-efficiency, and energy-saving crop harvesting device and its working process. Background Technology

[0002] Throughout the long history of agricultural technology development, the planting and harvesting of leafy vegetables has relied heavily on manual labor, with a lack of research and development of new, efficient equipment adaptable to varying ridge heights, plant spacing, and row spacing. This is particularly true in hilly and mountainous areas where the terrain is complex, the average household operation is small, and plots are fragmented. Both cost control and terrain considerations make large-scale traditional mechanized harvesting unsuitable. Therefore, the market for small-scale mechanized harvesting is enormous, creating an urgent need for efficient mechanized harvesting devices suitable for complex terrain and small-scale operations. This would improve production efficiency, reduce production costs, and promote the healthy development of the leafy vegetable industry.

[0003] Patent CN201523552U discloses a chive blossom harvester with a combined stepped frame as its base, mounted on a small hand-held tractor. Its design balances field of vision, maneuverability, simple structure, and strong safety performance, minimizing the risk of accidents. However, its movement relies on the small tractor, preventing autonomous and self-adaptive movement.

[0004] Patent CN114651604A discloses a pickled mustard tuber harvester with a cleaning device, which solves the problem of existing pickled mustard tuber harvesters leaving a lot of stems and leaves on the heads of the harvested vegetables. However, this device overlooks the problem that some soil will remain on the stems near the roots during the harvesting process.

[0005] The patent with publication number CN215073980U discloses a rotary top-loading vegetable harvester that can achieve efficient and independent movement, but its body structure is fixed and its height cannot be adjusted, making it unable to adapt to different field ridge heights.

[0006] Therefore, existing small-scale crop harvesters are insufficient to achieve simple, efficient, and adaptive crop harvesting. First, due to the diverse shapes of crops, some fixed-device harvesting methods cannot accurately and nimbly harvest different crops. Second, because crops are highly adaptable to their environment, the size and height of their ridges vary greatly, and some fixed-device harvesters cannot adjust their height to accommodate different ridge heights. Summary of the Invention

[0007] In view of the above-mentioned problems in the prior art, the purpose of this invention is to provide a self-balancing, high-efficiency and energy-saving crop harvesting device and its working process.

[0008] This invention provides the following technical solution:

[0009] A self-balancing crop harvesting device includes a main frame, on which a gripping mechanism for gripping crops and a soil-sieving mechanism for placing crops and sieving soil are provided. The soil-sieving mechanism is oscillatingly mounted on the main frame and moves in conjunction with the gripping mechanism. Walking mechanisms are provided on both sides of the main frame, and the walking mechanisms on both sides can achieve independent walking and lifting movements respectively.

[0010] Furthermore, the gripping mechanism includes a gripping drive and a robotic arm. The output end of the gripping drive is connected to the robotic arm through a crank-rocker mechanism. The robotic arm is movably mounted on the main frame and has flexible grippers on it.

[0011] Furthermore, the gripping drive is connected to the soil screening mechanism via a first gear transmission assembly and a cam mechanism; the cam mechanism includes a conjugate cam mechanism, a driven member, and a swing arm. The output end of the gripping drive is connected to the conjugate cam mechanism via the first gear transmission assembly. The conjugate cam mechanism and the driven member are configured to cooperate with each other. The driven member is connected to the soil screening mechanism via the swing arm. The soil screening mechanism includes a housing with an inlet on one side and a set of screening slots on the side and bottom of the housing.

[0012] Furthermore, the conjugate cam mechanism is movably mounted on the main frame, and one side of the follower is configured to cooperate with the conjugate cam mechanism. Its middle part is movably connected to the main frame, and its other side is hinged to one end of the swing arm. The other end of the swing arm is hinged to the housing.

[0013] Furthermore, when the two cams in the conjugate cam mechanism move to the rest circle under the drive of the gripping drive, the flexible gripper moves to directly above the entrance of the box, so as to ensure that the gripped crops are placed into the box in a stationary state.

[0014] Furthermore, the walking mechanisms on both sides achieve self-balancing control through an external control system. The walking mechanism includes a lifting drive component and two walking wheel mechanisms arranged in front and behind. The lifting drive component drives the two walking wheel mechanisms to lift and lower synchronously via a second gear transmission assembly. The walking wheel mechanism includes a walking wheel, which is connected to the second gear transmission assembly in sequence through a stabilizing linkage mechanism and a lifting linkage mechanism. At least one walking wheel is equipped with a walking drive component.

[0015] Furthermore, the walking wheel mechanism also includes a wheel mounting seat, on which the walking wheel is movably mounted; the stabilizing linkage mechanism includes an upper linkage and a lower linkage, one end of which is movably connected to the main frame, and the other end of which is movably connected to the wheel mounting seat, and the four movable connecting pairs are combined to form a parallelogram linkage structure; the lifting linkage mechanism includes a first linkage and a second linkage, one end of which is drivenly connected to the second gear transmission assembly, and the other end of which is connected to the second linkage, and the other end of which is movably connected to the upper linkage.

[0016] Furthermore, it also includes an energy recovery mechanism, which includes a follower and a ratchet and pawl mechanism. The follower and the ratchet and pawl mechanism are connected by a gear transmission mechanism. The follower is fixedly connected to the gripping mechanism, and the ratchet and pawl mechanism is connected to the rotor of an external generator.

[0017] A method for operating a self-balancing crop harvesting device includes the following steps:

[0018] S1. When the crop harvesting device is placed in the field ridge, the lifting drive component in the walking mechanism on both sides is independently controlled by the external self-balancing control system. The walking wheel is driven to rise and fall to the required height through the second gear transmission assembly, the stabilizing linkage mechanism and the lifting linkage mechanism to adapt to the terrain of different heights in the field ridge. Then, the walking drive component is started to control the walking wheel to drive the entire crop harvesting device forward to the position where the crop needs to be grabbed.

[0019] S2. Control the gripper power component on the flexible gripper to keep the flexible gripper in an open state and maintain it; control the operation of the gripping drive component to drive the crank rocker mechanism to move the mechanical arm downward to the gripping position; at this time, the cam mechanism connected to the gripping drive component rotates in conjunction, causing the box in the soil screening mechanism to tilt; then control the gripper power component to grip the crops and keep the gripping posture of the flexible gripper unchanged.

[0020] S3. Utilizing the quick-return characteristic of the crank-rocker mechanism, the robotic arm lifts backward, and the soil screening mechanism moves in tandem with it, causing the box to return to a horizontal state. At this time, the crops gripped are positioned above the entrance of the box, and both cams of the conjugate cam mechanism in the cam mechanism enter the rest circle, controlling the gripper power component to release the flexible gripper, allowing the crops to fall into the box. Simultaneously, the energy recovery mechanism converts the quick-return motion of the crank-rocker mechanism into energy.

[0021] S4. During the next grabbing, the cam mechanism is linked with the grabbing mechanism, causing the box to shake to sieve the soil, and the cycle is repeated to complete the harvest of all crops.

[0022] A method for operating a self-balancing crop harvesting device, characterized in that the energy recovery mechanism performs the energy conversion of the rapid return motion of the crank-rocker mechanism as follows:

[0023] When the crank-rocker mechanism returns to its original position quickly due to its quick-return characteristic, it drives the follower-driven gear transmission mechanism through a first-stage acceleration, which in turn drives the pawl in the ratchet-pawl mechanism to hook onto the ratchet and rotate it. The ratchet then drives the generator rotor to rotate and generate electricity. When the gripping mechanism is working, the pawl moves in the opposite direction and does not exert any force on the ratchet, so it does not hinder the normal operation of the gripping mechanism.

[0024] By employing the above-described technology, the beneficial effects of the present invention compared to the prior art are as follows:

[0025] 1) The walking mechanism of the device of the present invention achieves lifting and lowering through a linkage mechanism, which can adapt to field ridges of different heights; through independent self-balancing lifting and lowering control on both sides, it can adapt to field ridges of different widths by taking advantage of the already harvested field ridges and the surrounding terrain, thereby improving the adaptability of the device.

[0026] 2) The gripping mechanism of the device of the present invention adopts a crank-rocker mechanism combined with a robotic arm structure design. The quick return characteristic of the crank-rocker mechanism enables the robotic arm to return to its position efficiently, thereby improving the working efficiency of the robotic arm and improving the continuity of operation.

[0027] 3) This invention uses a single power source to control the linkage motion of the gripping mechanism and the soil screening mechanism. Through the design of transmission and timing, the overall structure is more compact, the energy utilization rate is higher, and the control is more precise.

[0028] 4) In this invention, by setting a cam mechanism, based on the design of a conjugate cam mechanism, the box in the soil screening mechanism can be made to shake and sway in conjunction during the control of the movement of the gripping mechanism to achieve soil screening; and when the two cams in the conjugate cam mechanism move into the rest circle, the position of the flexible gripper after gripping the crop is exactly corresponding to the entrance of the box, so that the crop can be placed in the box in a relatively static state of the mechanism to achieve accurate collection.

[0029] 5) In this invention, by setting up an energy recovery mechanism, in conjunction with the rapid return motion of the crank slider, the kinetic energy during rapid return can be converted into the rotational motion of the ratchet, thereby driving the generator rotor to rotate and generate electricity, thus achieving full energy recovery. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall three-dimensional structure in Embodiment 1 of the present invention;

[0031] Figure 2 This is a schematic diagram of the gripping mechanism and the soil screening mechanism in Embodiment 1 of the present invention;

[0032] Figure 3 This is a schematic diagram of the cam mechanism in Embodiment 1 of the present invention;

[0033] Figure 4 This is a schematic diagram of the walking mechanism in Embodiment 1 of the present invention;

[0034] Figure 5 This is a schematic diagram illustrating the principle of the gripping mechanism in Embodiment 1 of the present invention;

[0035] Figure 6 This is a schematic diagram of the principle of the conjugate cam mechanism in Embodiment 1 of the present invention, wherein 6a is a schematic diagram of the arrangement of the housing and the cam mechanism, 6b is a schematic diagram of the working principle of the cam linkage mechanism, 6c is a schematic diagram of the pressure angle verification of a single cam, and 6d is a schematic diagram of the working range of the conjugate cam follower.

[0036] Figure 7 This is a schematic diagram of the lifting principle of the walking mechanism in Embodiment 1 of the present invention, wherein 7a is a schematic diagram of the lifting limit position and 7b is a schematic diagram of the normal working position;

[0037] Figure 8 This is a schematic diagram of the overall structure of the device in Embodiment 2 of the present invention;

[0038] Figure 9 This is a schematic diagram of the assembly structure of the energy recovery mechanism in Embodiment 2 of the present invention.

[0039] Figure 10 This is a schematic diagram of the energy recovery mechanism in Embodiment 2 of the present invention. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0041] Conversely, this invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of the invention as defined in the claims. Furthermore, to provide a better understanding of the invention, certain specific details are described in detail below. However, those skilled in the art will fully understand the invention even without these detailed descriptions.

[0042] Example 1

[0043] This embodiment takes the harvesting of leafy vegetables such as bok choy as an example:

[0044] Please see Figure 1-7A self-balancing, high-efficiency and energy-saving crop harvesting device includes a main frame 1 and a gripping mechanism 2, a soil screening mechanism 3, a walking mechanism 4, a cam mechanism 5 and a first gear transmission assembly 6, all mounted on the main frame 1.

[0045] Specifically, the main frame 1 includes a bottom frame 11 and a vertical frame 12 set on the bottom frame 11, and the vertical frame 12 is provided with a mounting plate 13.

[0046] Specifically, the gripping mechanism 2 includes a gripping drive component 21, a robotic arm 22, a crank-rocker mechanism 23, a flexible gripper 24, and a gripper power component.

[0047] The gripping drive 21 is a motor, which is fixed on the bottom frame 11. The crank-rocker mechanism 23 includes a crank 231, a rocker arm 232, and two sliders 233. One end of the crank 231 is connected to the output end of the gripping drive 21, and the other end is movably connected to one end of the rocker arm 232. One slider 233 is movably mounted on the vertical frame 12 via a rotating shaft, and the other slider 233 is fixed to the robotic arm 22. The rocker arm 232 is slidably mounted on the two sliders 233. One end of the robotic arm 22 is movably mounted on the vertical frame 12 via a rotating shaft, and the flexible gripper 24 is mounted on the other end of the robotic arm 22. The gripper is controlled by a gripper power component, which is a servo motor.

[0048] Specifically, the soil screening mechanism 3 includes a box 31, with an inlet 311 on one side of the box 31 and multiple screening slots 312 on the bottom and the other side of the box 31.

[0049] The gripping drive component 21 is connected to the soil screening mechanism 3 through the first gear transmission assembly 6 and the cam mechanism 5.

[0050] The cam mechanism 5 includes a conjugate cam mechanism 51, a follower 52, and a swing arm 53; the first gear transmission assembly 6 is fixed on the bottom frame 11; the conjugate cam mechanism 51 is movably mounted on the mounting plate 13, the cam has a pressure angle of 35°, a cam rotation angle of 80°, and a base circle radius of 60mm; the output end of the gripping drive component 21 is connected to the conjugate cam mechanism 51 through the first gear transmission assembly 6, driving the conjugate cam mechanism 51 to rotate; the follower 52 is configured to cooperate with the conjugate cam mechanism 51, which is the conventional configuration of the conjugate cam mechanism. The middle part of the follower 52 is movably mounted on the mounting plate 13, and the other end is movably connected to one end of the swing arm 53, the other end of the swing arm 53 is movably mounted on the housing 31.

[0051] Specifically, the walking mechanism 4 is controlled by a self-balancing function system. There are two sets of walking mechanisms 4, which are respectively set on both sides of the bottom frame 11 and can independently control walking and lifting. The walking mechanism 4 includes a lifting drive component 41, a second gear transmission assembly 42 and two walking wheel mechanisms.

[0052] The automatic balancing control system uses an MPU6050 gyroscope module and corresponding sensors to perform real-time attitude detection of the device, and an STM32F103C8T6 as the main controller. When the self-balancing control system is activated, and the sensors detect a roll angle greater than 5 degrees, the main control chip will control the lower-side walking mechanism 4 to rise to the appropriate height, keeping the entire device level, which is beneficial for crop harvesting.

[0053] Two traveling wheel mechanisms in the same traveling mechanism 4 are respectively located on the front and rear sides of one side of the bottom frame 11. Each mechanism includes a lifting drive component 41, a traveling wheel 43, a stabilizing linkage mechanism 44, a lifting linkage mechanism 45, a traveling drive component 46, and a wheel mounting seat 47. The output end of the lifting drive component 41 is connected to a second gear transmission assembly 42.

[0054] The traveling wheel 43 is movably mounted on the wheel mounting seat 47. The output end of the lifting drive component 41 controls the lifting of the traveling wheel 43 via the second gear transmission assembly 42, the stabilizing linkage mechanism 44 and the lifting linkage mechanism 45. The second gear transmission assembly 42 includes two gears, which drive the two traveling wheel mechanisms to move in linkage.

[0055] The stabilizing linkage mechanism 44 includes an upper linkage 441 and a lower linkage 442. One end of the upper linkage 441 and the lower linkage 442 are movably connected to the main frame 1, and the other end is movably connected to the wheel mounting seat 47. The four movable connecting pairs are combined to form a parallelogram linkage structure. The lifting linkage mechanism 45 includes a first linkage 451 and a second linkage 452. One end of the first linkage 451 is connected to the second gear transmission assembly 42, and the other end is connected to the second linkage 452. The other end of the second linkage 452 is movably connected to the upper linkage 441.

[0056] In the same walking mechanism 4, at least one walking wheel 43 is connected to a walking drive component 46. The walking drive component 46 is a motor used to drive the walking wheel 43 to rotate in order to complete the walking motion.

[0057] The working process of the device in this embodiment is as follows:

[0058] If the device encounters a higher ridge, it will perform the following operations:

[0059] Adjust the walking mechanisms 4 on both sides, start the lifting drive component 41 in the walking mechanism 4, drive the two gears in the corresponding second gear transmission component 42 to mesh and rotate, synchronously drive the corresponding lifting linkage mechanism 45 and stabilizing linkage mechanism 44 to move, and then drive the walking wheels 43 on both sides to independently adjust the height, so as to achieve the purpose of adapting to different height ridges.

[0060] When the device is raised or lowered, the design of the parallelogram linkage structure ensures that the motor support remains stable and highly reliable.

[0061] The specific steps during the operation of the device are as follows:

[0062] S1. Place the crop harvesting device in the field ridge, connect the power supply, and control the lifting drive component 41 in the walking mechanism 4 on both sides respectively. Through the linkage mechanism 44 and the lifting linkage mechanism 45, adjust the walking wheel 43 to the required height; start the walking drive component 46 to control the walking wheel 43 to drive the entire crop harvesting device forward to the position where the crop needs to be grabbed.

[0063] S2. Control the gripper power component on the flexible gripper 24 to keep the flexible gripper 24 in an open state; control the gripping drive component 21 to run, and drive the mechanical arm 22 to move downward to the gripping position through the crank rocker mechanism 23; at this time, the cam mechanism 5 connected to the gripping drive component 21 rotates, causing the box 31 in the soil screening mechanism 3 to tilt; then control the gripper power component to grip the crops, and keep the gripping posture of the flexible gripper 24 unchanged.

[0064] S3. Utilizing the quick-return characteristic of the crank-rocker mechanism 23, the robotic arm 22 is lifted backward, and the soil screening mechanism 3 moves in conjunction with it, causing the box 31 to return to a horizontal state. At this time, the crops gripped are exactly above the inlet 311 on the box 31, and both cams of the conjugate cam mechanism 51 in the cam mechanism 5 enter the rest circle, controlling the gripper power component to release the flexible gripper 24, and the crops fall into the box 31.

[0065] S4. During the next grabbing, the cam mechanism 5 is linked with the grabbing mechanism 2, causing the box 31 to shake to achieve soil sieving, and the cycle is repeated to complete the harvest of all crops.

[0066] Example 2

[0067] Based on the device structure of Embodiment 1, an energy recovery mechanism 7 is added. The energy recovery mechanism 7 includes a follower 701, a ratchet and pawl mechanism 702, and a gear transmission mechanism. The follower 701 is fixedly connected to the gripping mechanism 2. When the gripping mechanism 2 places the crops into the housing 31, it quickly returns to its original position under the drive of the crank-slider's quick-return characteristic. This drives the follower 701 to drive the gear transmission mechanism through a first-stage acceleration, which in turn drives the two symmetrically distributed pawls in the ratchet and pawl mechanism 702. At this time, the pawls hook onto the ratchet, causing the ratchet to rotate. The ratchet then drives the generator rotor to rotate and generate electricity. During the operation of the gripping mechanism, the pawls moving in the opposite direction will not hook onto the ratchet and will not hinder the operation of the gripping mechanism 2.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A self-balancing crop harvesting device, characterized in that, The utility model provides a kind of agricultural product picking and screening device, including main body frame (1), the main body frame (1) is equipped with for grabbing agricultural product and for placing agricultural product and screening soil and screening soil mechanism (3) of agricultural product, screening soil mechanism (3) can swing setting in main body frame (1), and with grabbing mechanism (2) linkage movement;The both sides of the main body frame (1) are equipped with walking mechanism (4), and the walking mechanism (4) of both sides can realize independent walking and lifting movement respectively; The grabbing mechanism (2) includes grabbing drive part (21) and mechanical arm (22), and the output end of the grabbing drive part (21) is connected with the mechanical arm (22) through a crank rocker mechanism (23), and the mechanical arm (22) is movably arranged on the main body frame (1), and a flexible gripper (24) is arranged on the mechanical arm (22). The grabbing drive part (21) is connected with the screening soil mechanism (3) through a first gear transmission assembly (6) and a cam mechanism (5), and the cam mechanism (5) includes a conjugate cam mechanism (51), a follower (52) and a swing arm (53), the output end of the grabbing drive part (21) is drivingly connected with the conjugate cam mechanism (51) through the first gear transmission assembly (6), the conjugate cam mechanism (51) is cooperatively arranged with the follower (52), and the follower (52) is connected with the screening soil mechanism (3) through the swing arm (53), and the screening soil mechanism (3) includes a box body (31), one side of the box body (31) is provided with an inlet (311), and a group of screening grooves (312) are formed in the side and bottom of the box body (31). The conjugate cam mechanism (51) is movably arranged on the main body frame (1), one side of the follower (52) is cooperatively arranged with the conjugate cam mechanism (51), the middle part of the follower (52) is movably connected with the main body frame (1), the other side of the follower (52) is hingedly connected with one end of the swing arm (53), and the other end of the swing arm (53) is hingedly arranged on the box body (31). When the two cams in the conjugate cam mechanism (51) are driven by the grabbing drive part (21) to move to the rest circle, the flexible gripper (24) moves to the top of the inlet (311) of the box body (31), so as to ensure that the grabbed agricultural product is placed in the box body (31) in the static state.

2. A self-leveling crop harvesting device according to claim 1, characterized in that, The walking mechanism (4) on both sides realizes self-balancing control through an external control system, and the walking mechanism (4) includes a lifting drive part (41) and two walking wheel mechanisms arranged in front and back, the lifting drive part (41) drivingly drives the two walking wheel mechanisms to synchronously lift and lower through a second gear transmission assembly (42), and the walking wheel mechanism includes a walking wheel (43), the walking wheel (43) is connected with the second gear transmission assembly (42) in sequence through a stabilizing linkage mechanism (44) and a lifting linkage mechanism (45), and at least one walking wheel (43) is provided with a walking drive part (46).

3. A self-leveling crop harvesting device according to claim 2, characterized in that The walking wheel mechanism further comprises a wheel mounting seat (47), and the walking wheel (43) is movably mounted on the wheel mounting seat (47); the stabilizing linkage mechanism (44) comprises an upper linkage (441) and a lower linkage (442), one end of the upper linkage (441) and one end of the lower linkage (442) are movably connected with the main body frame (1) respectively, and the other end of the upper linkage (441) and the other end of the lower linkage (442) are movably connected with the wheel mounting seat (47) respectively, and four movable connection pairs are combined to form a parallelogram linkage structure; the lifting linkage mechanism (45) comprises a first linkage (451) and a second linkage (452), one end of the first linkage (451) is in transmission connection with the second gear transmission assembly (42), the other end of the first linkage (451) is connected with the second linkage (452), and the other end of the second linkage (452) is movably connected with the upper linkage (441).

4. A self-leveling crop harvesting device according to claim 3, wherein, Further comprising an energy recovery mechanism (7) comprising a follower (701) and a ratchet and pawl mechanism (702), the follower (701) and the ratchet and pawl mechanism (702) are in transmission connection through a gear transmission mechanism, the follower (701) is fixedly connected with the grabbing mechanism (2), and the ratchet and pawl mechanism (702) is connected with a rotor of an external generator.

5. A method of operating a self-leveling crop harvesting device according to claim 4, wherein, The method comprises the following steps: S1, when the crop harvesting device is placed in the field ridge, the lifting drive (41) in the two walking mechanisms (4) is independently controlled through an external self-balancing control system, the walking wheel (43) is lifted to a required height through the second gear transmission assembly (42), the stabilizing linkage mechanism (44) and the lifting linkage mechanism (45) to adapt to the different height terrains in the field ridge, then the walking drive (46) is started to control the walking wheel (43) to drive the whole crop harvesting device to advance to a position where crops need to be grabbed; S2, the gripper power element on the flexible gripper (24) is controlled to make the flexible gripper (24) in an open state and keep it; the grabbing drive (21) is controlled to operate to drive the crank rocker mechanism (23) to drive the mechanical arm (22) to move downward to a grabbing position; at this time, the cam mechanism (5) connected with the grabbing drive (21) is linked to rotate to drive the box (31) in the soil screening mechanism (3) to dump; the crop is grabbed again through the control of the gripper power element, and the grabbing posture of the flexible gripper (24) is kept unchanged; S3, the mechanical arm (22) is lifted backward by using the quick-return characteristic of the crank rocker mechanism (23), the soil screening mechanism (3) is linked therewith, the box (31) returns to a horizontal state, at this time, the grabbed crops are just above the inlet (311) of the box (31), and the two cams of the conjugate cam mechanism (51) in the cam mechanism (5) all enter the rest circle, the gripper power element is controlled to release the flexible gripper (24), and the crops fall into the box (31); meanwhile, the energy recovery mechanism (7) converts the energy of the quick-return return movement of the crank rocker mechanism (23); S4, when the next time of grabbing, the cam mechanism (5) is linked with the grabbing mechanism (2) to drive the box (31) to shake to realize soil screening, and the harvesting of all crops is completed through the circulation and repetition.

6. A method of operating a self-leveling crop harvesting device according to claim 5, wherein, The specific process of energy conversion of the energy recovery mechanism (7) to the quick return movement of the crank rocker mechanism (23) is as follows: When the crank rocker mechanism (23) is quickly returned under the drive of the quick return characteristic, the follower (701) drives the gear transmission mechanism to pass through one-stage acceleration, the pawl in the ratchet and pawl mechanism (702) hooks the ratchet to drive the ratchet to rotate, the ratchet drives the generator rotor to rotate to generate electricity; when the grabbing mechanism (2) works, the pawl moves in the opposite direction and does not have force action with the ratchet, and does not hinder the normal work of the grabbing mechanism (2).

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