Paddy field bionic walking device
By using a biomimetic walking device that mimics the leg movements of a duck, the problems of turning difficulties and soil damage in paddy fields have been solved, achieving stability and adaptability, avoiding damage to seedlings, and improving the reliability of paddy field operations.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENYANG AGRI UNIV
- Filing Date
- 2026-01-07
- Publication Date
- 2026-04-21
AI Technical Summary
Existing paddy field walking devices have difficulty turning in muddy soil, damage the soil environment, and crush or injure seedlings, and have poor adaptability.
Adopting a biomimetic design, mimicking the leg movements of a duck, it employs a walking mechanism that utilizes the support structure of mechanical legs, palms, and toes to open and close in mud. Combined with a symmetrical layout and transmission mechanism, it provides a power and steering system to ensure stability and adaptability.
It improves stability when walking in muddy soil, reduces soil damage, avoids crushing or damaging seedlings, allows for flexible turning and adaptability to rice planting row spacing, and improves the reliability and efficiency of operations.
Smart Images
Figure CN121894071A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of agricultural machinery technology, specifically to a biomimetic walking device for paddy fields, which can adapt to the muddy environment of paddy fields and achieve walking. Background Technology
[0002] Field management of rice directly affects yield. Currently, drones are mostly used for spraying pesticides and fertilizers in weeding and fertilization, but this method has problems such as low pesticide and fertilizer utilization and serious environmental pollution. To improve pesticide and fertilizer utilization, weeding and fertilization machinery is now being used directly in the fields during the middle stage of rice growth. The locomotives of paddy field machinery are generally tracked, wheeled, or propeller-driven. Wheeled locomotives are suitable for paddy fields with low water levels and stable ground, but not for fields with deep mud or uneven terrain. Tracked locomotives have complex structures and high manufacturing costs. Propeller-driven locomotives are complex in design and large in size, limiting their application in small spaces or delicate operations, and are also more difficult to maintain and operate.
[0003] Due to the complexity of the paddy field environment, the contact surface between the machinery and the mud is hidden below the water surface, making it difficult to assess the underwater mud conditions. This can cause the machine to sink, affecting its stability. The low strength and muddy texture of the mud make the machine prone to skidding and getting stuck in the mud, and turning becomes difficult. Furthermore, the small spacing between rice seedlings in the planting rows limits the working space. Therefore, the current walking devices have significant limitations. Mechanical operation in paddy fields can damage the soil environment, causing difficulties in later operations and even leading to problems such as damaging or crushing seedlings. Summary of the Invention
[0004] In order to overcome the problem of poor adaptability of existing walking devices in paddy field muddy soil environment, the purpose of this invention is to provide a biomimetic walking device for paddy fields. This device solves the problems of difficulty in turning in muddy paddy soil, damage to soil environment and damage to seedlings caused by general walking mechanisms.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A biomimetic paddy field walking device includes a frame, a transmission mechanism, a power system, and four mechanical legs. Two mechanical legs are located on each side of the frame, and each mechanical leg includes a leg mechanism and a foot assembly. The power system is mounted on the frame, and transmits power to the leg mechanisms via the transmission mechanism, enabling the legs to lift and lower. The foot assembly includes a supporting foot, a middle toe, and two lateral toes. When the leg mechanism lowers the supporting foot, the lateral toes open, increasing the contact area with the mud and preventing the walking device from sinking. When the leg mechanism lifts the supporting foot, the lateral toes retract, reducing the resistance between the foot and the mud.
[0006] The frame includes a front frame and a rear frame. A pair of mechanical legs are provided on the lower sides of both sides of the front frame and the lower sides of both sides of the rear frame. The mechanical legs on both sides of the frame are mirror-symmetrical, and the front and rear mechanical legs on each side have the same structure.
[0007] The walking device also includes a steering system, which includes bevel gear I, bevel gear II, and a hinge pin. The rear end of the front frame and the front end of the rear frame are connected by the hinge pin. Bevel gear I and bevel gear II mesh at 90°. Bevel gear II is connected to the hinge pin, which is fixed to the rear frame. A stepper motor installed at the rear end of the front frame drives bevel gear I to rotate and drives bevel gear II to rotate, which in turn drives the hinge pin to move. This enables the front and rear frames to deflect, thus completing the turning of the walking device.
[0008] The rear end face of the front frame has a T-shaped piece, the head of the T-shaped piece is fixed to the rear end face of the front frame, and the tail of the T-shaped piece has a shaft hole. The lower front end of the rear frame is provided with a support platform. The hinge pin is inserted into the shaft hole of the T-shaped piece and its lower end is fixed to the support platform. The hinge pin can rotate in the shaft hole.
[0009] The power system is a gasoline engine, with one gasoline engine mounted on the top of the front frame and one on the top of the rear frame. The gasoline engines provide power to the transmission mechanism.
[0010] The transmission mechanism is a cam-linkage combination structure, including a cam, a multi-linkage mechanism, and a triangular connector. The cam and the triangular connector are fixed on the frame. The connection points of the two cams on opposite sides of the frame with the multi-linkage mechanism are at the same position. The multi-linkage mechanism includes link I, link II, link III, and link IV. The three corners of the triangular connector are respectively hinged to one end of link I, link III, and link IV. The other end of link I is hinged to the edge of the cam, which is also hinged to one end of link II. The other end of link II is hinged to the upper front end of the leg component. The other ends of link III and link IV are respectively hinged to the upper rear end and upper front end of the leg component.
[0011] The leg mechanism includes a leg support, the upper middle part of which is connected to the front end of the supporting palm via leg link A and leg link B in sequence; the lower middle part of which is connected to the middle part of the supporting palm via leg link C and leg link D in sequence; and the lower end of the leg support is connected to the rear end of the supporting palm; all connections are hinged.
[0012] In the foot assembly, the front end of the supporting foot has a middle toe and two side toes on either side of the middle toe; the middle toe is fixedly connected to the front end of the supporting foot and remains stationary, and a slider is fitted on the middle toe; the two side toes are connected to the front end of the supporting foot through cylindrical pins, and at the same time, the two side toes are connected to the middle toe through sliders.
[0013] In the foot assembly, the two lateral toes are lateral toe I and lateral toe II. Lateral toe I and lateral toe II are respectively hinged to the two sides of the slider via foot link A and foot link B. The top of the slider is hinged to the lower end of the leg link B.
[0014] When the supporting palm falls, the lateral toes on both sides open; when the supporting palm is lifted, the lateral toes on both sides contract. Specifically: the middle toe remains stationary; when the supporting palm is lifted, the leg link B is subjected to downward pressure, and the slider on the middle toe moves forward under the thrust of the leg link B. The foot link A and foot link B are connected to lateral toe I and lateral toe II respectively. The forward movement of the slider drives the foot link A and foot link B, causing lateral toe I and lateral toe II to contract inward in a planar fixed-point circular motion, and the lateral toes as a whole undergo a contraction motion. When the middle toe remains stationary, when the supporting palm falls, the leg link B is subjected to upward pulling force, and the slider on the middle toe moves backward under the pulling force of the leg link B, moving along a trajectory opposite to the lifting process. The slider drives the foot link A and foot link B, causing the toes to open outward in a planar fixed-point circular motion, and the lateral toes as a whole undergo an extension motion.
[0015] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: 1. This invention changes the traditional tracked or wheeled walking method. By imitating the walking movement of ducks' legs and webbed feet, it adopts a walking posture with two mechanical claws moving one in front of the other and one lifting and lowering. When the bionic claws fall, the toes spread out. When the claws are pulled out, the mechanical structure pulls the three toes together, which solves the problems of ordinary walking mechanisms having difficulty turning in muddy paddy fields, damaging the soil environment, and crushing and damaging seedlings.
[0016] 2. In the walking device of the present invention, when the leg mechanism drives the supporting palm to fall, the lateral toes on both sides of the middle toe open to increase the contact area with the mud and prevent the walking device from sinking; when the leg mechanism drives the supporting palm to lift, the lateral toes on both sides of the middle toe contract to reduce the resistance between the foot and the mud.
[0017] 3. To ensure overall machine balance, the walking device of this invention adopts a symmetrical layout with a four-legged design, two legs on each side, and the spacing between each leg remains consistent. By maintaining the consistency of the spacing between each leg, the walking device can adapt to standardized rice planting row spacing, effectively avoiding damage to the crop.
[0018] 4. The walking device of this invention uses a gasoline engine for power and converts the rotational motion of the power mechanism into the walking motion of the legs through a multi-link mechanism, cams, and triangular connectors. Furthermore, the transmission mechanism can change the torque output of the power engine according to operational needs to adapt to various working conditions. A disc-shaped cam enables the lifting and rotation of the mechanical legs. Linkages ensure the claws remain parallel to the ground, guaranteeing stability and reliability during walking. The left and right cams are connected to the multi-link mechanism, enabling the two legs to walk in a forward-backward posture, mimicking biological walking and improving the adaptability of the mechanism. The foot portion reduces the resistance of the mud in the paddy field to the claws during movement, and also greatly reduces damage to crops and the paddy field environment.
[0019] 5. The steering system of this invention uses two mutually perpendicular bevel gears to achieve rotation and positioning of the traveling device's direction of travel. Bevel gear I is driven by a stepper motor, and bevel gear II is fixed on the frame. When bevel gear I rotates, it meshes with bevel gear II, allowing the front and rear frames to deflect relative to each other around their hinge pins. Depending on the operational requirements, the steering system keeps the traveling device stable in a straight line or flexibly changes its direction of travel. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the overall structure of the biomimetic paddy field walking device of the present invention.
[0021] Figure 2 This is a schematic diagram of the power system of the biomimetic paddy field walking device of the present invention.
[0022] Figure 3 This is a schematic diagram of the steering system of the biomimetic paddy field walking device of the present invention.
[0023] Figure 4 This is a schematic diagram of the leg and foot structure of the biomimetic paddy field walking device of the present invention.
[0024] Figure 5 This is a schematic diagram of the cam in the biomimetic paddy field walking device of the present invention.
[0025] In the diagram: 100-Frame, 11-Rear frame; 12-Front frame; 200-Transmission mechanism, 21-Cam, 22-Multi-link mechanism, 221-Link I, 222-Link II, 223-Link III, 224-Link IV, 23-Triangular connector, 300-Power system, 31-Drive shaft, 400-Steering system, 41-Stepper motor, 42-Bevel gear I, 43-Bevel gear II, 44-Hinge pin, 500-Foot assembly, 51-Support foot, 52-Foot link A, 53-Slider, 54-Foot link B, 55-Middle toe, 56-Side toe II, 57-Side toe I, 600-Leg mechanism, 61-Leg support, 62-Leg link B, 63-Leg link A, 64-Leg link C, 65-Leg link D. Detailed Implementation
[0026] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings.
[0027] This invention provides a biomimetic paddy field walking device, such as... Figure 1-5 As shown. The walking device includes a frame 100, a transmission mechanism 200, a power system 300, a steering system 400, and four mechanical legs. The frame 100 includes a front frame 12 and a rear frame 11, with a pair of mechanical legs located on the lower sides of both the front frame 12 and the lower sides of both the rear frame 11. The steering system 400 connects both the front frame 12 and the rear frame 11, enabling deflection movements of the front and rear frames. Each mechanical leg includes a leg mechanism 600 and a foot assembly 500. The power system 300 is mounted on the frame 100, transmitting power to the leg mechanism 600 via the transmission mechanism 200, enabling the leg mechanism 600 to lift and lower. The lifting and lowering of the leg mechanism 600 causes the foot assembly 500 to extend and retract. The specific structure and connection relationships of each part of the walking device are as follows: like Figure 1 As shown, the mechanical legs on both sides below the frame 100 are mirror symmetrical, with the front and rear mechanical legs on each side having the same structure, and the distance between the two pairs of mechanical legs on both sides is the same.
[0028] like Figure 2 As shown, the power system 300 is a gasoline engine. A gasoline engine is installed on the top of the front frame 12 and the rear frame 11. The gasoline engine provides power to the transmission mechanism 200 (the gasoline engine drives the transmission shaft 31 to rotate, which in turn drives the cams 21 at both ends of the transmission shaft 31 to rotate synchronously).
[0029] like Figure 1 and Figure 3As shown, the steering system 400 includes bevel gear I 42, bevel gear II 43, and hinge pin 44. The rear end of the front frame 12 is connected to the front end of the rear frame 11 via hinge pin 44, forming a structure in which the front frame 12 and the rear frame 11 can rotate relative to each other. The bevel gear I 42 and bevel gear II 43 mesh at 90°, and bevel gear II 43 is fixedly connected to hinge pin 44. The rear end face of the front frame 12 has a T-shaped piece, the head of which is fixed to the rear end face of the front frame 12, and the tail of which has a shaft hole. The lower part of the front end of the rear frame 11 is provided with a support platform. The hinge pin 44 is inserted into the shaft hole of the T-shaped piece, and its lower end is fixed to the support platform. The hinge pin 44 is rotatable in the shaft hole. A stepper motor 41 is installed at the rear end of the front frame 12. The stepper motor 41 drives the bevel gear I 42 to rotate and drives the bevel gear II 43 to rotate, and further drives the hinge pin 44 to rotate relative to the shaft hole; thereby realizing the deflection action of the front frame and the rear frame, and realizing the turning of the walking device.
[0030] like Figure 1 As shown, the transmission mechanism 200 is a cam-linkage combination structure, including a cam 21, a multi-linkage mechanism 22, and a triangular connector 23. The cam 21 and the triangular connector 23 are fixed on the frame. The multi-linkage mechanism 22 includes link I 221, link II 222, link III 223, and link IV 224. The three corners of the triangular connector 23 are respectively hinged (pin-shafted) to one end of link I, link III, and link IV. The other end of link I is hinged to the edge of the cam (point a), which is also hinged to one end of link II. The other end of link II is hinged to the upper front end point (point b) of the leg mechanism. The other ends of link III and link IV are respectively hinged to the upper rear end point (point c) and the upper front end point (point b) of the leg mechanism.
[0031] Furthermore, the connection point (point a) between the two cams on both sides of each frame and the multi-link mechanism is a symmetrical point on the other side of the same diameter, thereby enabling the mechanical legs on the left and right sides to move forward and backward respectively.
[0032] like Figure 1 He Ru Figure 4 As shown, the leg mechanism 600 includes a leg support 61. The upper middle part of the leg support 61 is connected to the slider 53 at the front end of the supporting palm via leg link A and leg link B 62. The lower middle part of the leg support 61 is connected to the middle part of the supporting palm via leg link C 64 and leg link D 65. The lower end of the leg support 61 is connected to the rear end of the supporting palm. All connections are hinged.
[0033] like Figure 4As shown, the foot assembly 500 includes a supporting foot 51, a middle toe 55, and two lateral toes (lateral toe I 57 and lateral toe II 56) on both sides of the middle toe 55. The middle toe 55 is fixedly connected to the front end of the supporting foot and remains stationary. A slider 53 is fitted on the middle toe 55 (the slider 53 can slide along the middle toe 55). The two lateral toes are connected to the middle toe through the slider 53 (the lateral toes are hinged to the slider). At the same time, lateral toe I 57 and lateral toe II 56 are respectively hinged to the two sides of the slider 53 through foot connecting rod A 52 and foot connecting rod B 54. The top of the slider 53 is hinged to the lower end of the leg connecting rod B.
[0034] When the supporting palm falls, the lateral toes on both sides open; when the supporting palm is lifted, the lateral toes on both sides contract. Specifically: the middle toe remains stationary; when the supporting palm is lifted, the leg link B 62 is subjected to downward pressure, and the slider 53 on the middle toe 55 moves forward under the thrust of the leg link B 62. The foot link A 52 and foot link B 54 are connected to the lateral toe I 57 and lateral toe II 56 respectively. The forward movement of the slider drives the foot link A 52 and foot link B 54, causing the lateral toe I 57 and lateral toe II 56 to contract inward in a planar fixed-point circular motion, and the lateral toes as a whole undergo a contraction movement. The middle toe 55 remains stationary; when the supporting palm falls, the leg link B 62 is subjected to upward pulling force, and the slider 53 on the middle toe moves forward under the thrust of the leg link B 62. Under the pulling force of 62, it moves backward and moves along the trajectory opposite to the lifting process; the slider drives the foot connecting rod A52 and foot connecting rod B54 to make the toes open outward in a fixed-point circular motion in a plane, and the side toes as a whole extend.
[0035] The mechanism of the walking device of the present invention is as follows: The walking device is powered by a gasoline engine. The gasoline engine drives the cams on both sides to rotate via the transmission shaft above the frame, which in turn drives the multi-link mechanism to achieve the walking posture of the two mechanical legs moving forward and backward, lifting and lowering. The steering system uses two mutually perpendicular bevel gears to achieve rotation and positioning of the device's travel direction. Bevel gear I 42 is driven by a stepper motor 41, and bevel gear II 43 is fixed on the frame. When bevel gear I 42 rotates, it meshes with bevel gear II 43, and the front and rear frames can be relatively deflected around their hinge pin 44. The foot component 5 consists of a support foot 51 and three toes. The support foot has three toes at its front end. The middle toe 55 is fixed, and the two side toes are connected to the support foot by cylindrical pins and to the middle toe by sliders 53. When the bionic claw falls, the two side toes spread open, and when it is lifted, the two side toes retract. With the middle toe fixed, when the mechanical gripper lifts, the leg link B62 experiences downward pressure. The slider on the middle toe moves forward under the thrust of the leg link B62. The foot link A52 and foot link B54 are connected to the side toes 56 and 57. The forward movement of the slider drives the foot link A52 and foot link B54, causing the side toes 56 and 57 to contract inward in a planar fixed-point circular motion, resulting in a contraction movement of the toes as a whole. With the middle toe 55 fixed, when the mechanical gripper lowers, the leg link B62 experiences upward tension. The slider on the middle toe moves backward under the tension of the leg link B62, moving along a trajectory opposite to the lifting process. The slider drives the foot link A52 and foot link B54, causing the side toes 56 and 57 to open outward in a planar fixed-point circular motion, resulting in an extension movement of the toes as a whole.
[0036] In summary, this invention employs a gasoline engine-driven cam-connected assembly mechanism to achieve the lifting, lowering, and joint rotation of the mechanical leg. The foot assembly consists of a supporting foot and a three-toe mechanism. When the bionic claw descends, the toes on both sides spread out, increasing the contact area with the mud and preventing the walking device from sinking. When lifted, the toes on both sides retract, reducing the resistance between the foot and the mud. The steering mechanism uses two mutually perpendicular bevel gears, one fixed and the other meshing with it and rotating, driving the front and rear frames to produce a deflection action, thus enabling the walking device to turn.
[0037] This invention solves the problems of high walking resistance, difficulty in turning, damage to the paddy field soil environment, and crushing and damaging seedlings caused by general walking mechanisms in muddy soil environments.
[0038] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.
Claims
1. A biomimetic paddy field walking device, characterized in that: The walking device includes a frame (100), a transmission mechanism (200), a power system (300), and four mechanical legs. Two mechanical legs are located on each side of the frame, each including a leg mechanism (600) and a foot assembly (500). The frame is equipped with a power system (300), which transmits power to the leg mechanism (600) via the transmission mechanism (200), enabling the leg mechanism to lift and lower. The foot assembly (500) includes a support foot (51), a middle toe, and two side toes. When the leg mechanism (600) lowers the support foot (51), the side toes open, increasing the contact area with the mud and preventing the walking device from sinking. When the leg mechanism (600) lifts the support foot (51), the side toes retract, reducing the resistance between the foot and the mud.
2. The biomimetic paddy field walking device according to claim 1, characterized in that: The frame includes a front frame (12) and a rear frame (11). A pair of mechanical legs are provided on the lower sides of both sides of the front frame and the lower sides of both sides of the rear frame. The mechanical legs on both sides of the frame are mirror symmetrical, and the front and rear mechanical legs on each side have the same structure.
3. The biomimetic paddy field walking device according to claim 1, characterized in that: The walking device also includes a steering system (400), which includes bevel gear I (42), bevel gear II (43) and hinge pin (44). The rear end of the front frame (12) is connected to the front end of the rear frame (11) through the hinge pin (44). The bevel gear I (42) and bevel gear II (43) mesh at 90°. The bevel gear II (43) is connected to the hinge pin (44), and the hinge pin (44) is fixed on the rear frame (11). The stepper motor (41) installed at the rear end of the front frame (12) drives the bevel gear I (42) to rotate and drives the bevel gear II (43) to rotate, and further drives the hinge pin (44) to move. This enables the front frame and the rear frame to deflect, thus enabling the walking device to turn.
4. The biomimetic paddy field walking device according to claim 3, characterized in that: The rear end face of the front frame (12) has a T-shaped piece, the head of the T-shaped piece is fixed on the rear end face of the front frame, and the tail of the T-shaped piece has a shaft hole. The lower front end of the rear frame (11) is provided with a support platform. The hinge pin (44) is inserted into the shaft hole of the T-shaped piece and its lower end is fixed to the support platform. The hinge pin (44) can rotate in the shaft hole.
5. The biomimetic paddy field walking device according to claim 2, characterized in that: The power system (300) is a gasoline engine, with one gasoline engine mounted on the top of the front frame (12) and the rear frame (11), and the gasoline engine provides power to the transmission mechanism (200).
6. The biomimetic paddy field walking device according to claim 2, characterized in that: The transmission mechanism is a cam-linkage combination structure, including a cam (21), a multi-linkage mechanism (22), and a triangular connector (23). The cam (21) and the triangular connector (23) are fixed on the frame. The two cams on opposite sides of the frame are connected to the multi-linkage mechanism at the same position. The multi-linkage mechanism (22) includes link I, link II, link III, and link IV. The three corners of the triangular connector are respectively hinged to one end of link I, link III, and link IV. The other end of link I is hinged to the edge of the cam. The edge of the cam is also hinged to one end of link II. The other end of link II is hinged to the front end point above the leg component. The other ends of link III and link IV are respectively hinged to the rear end point and the front end point above the leg component.
7. The biomimetic paddy field walking device according to claim 6, characterized in that: The leg mechanism (600) includes a leg support (61), the upper middle part of which is connected to the front end of the supporting palm via leg link A and leg link B in sequence; the lower middle part of the leg support (61) is connected to the middle part of the supporting palm via leg link C and leg link D in sequence; and the lower end of the leg support (61) is connected to the rear end of the supporting palm; all connections are hinged.
8. The biomimetic paddy field walking device according to claim 7, characterized in that: In the foot assembly (500), the front end of the supporting foot is provided with a middle toe (55) and two side toes on both sides of the middle toe; the middle toe is fixedly connected to the front end of the supporting foot and remains stationary, and a slider (53) is sleeved on the middle toe; the two side toes are connected to the front end of the supporting foot through cylindrical pins, and at the same time, the two side toes are connected to the middle toe through the slider (53).
9. The biomimetic paddy field walking device according to claim 8, characterized in that: In the foot assembly, the two lateral toes are lateral toe I (57) and lateral toe II (56). Lateral toe I (57) and lateral toe II (56) are respectively hinged to the two sides of the slider (53) through foot link A (52) and foot link B (54). The top of the slider (53) is hinged to the lower end of the leg link B.
10. The biomimetic paddy field walking device according to claim 8, characterized in that: When the supporting palm falls, the lateral toes on both sides open; when the supporting palm is lifted, the lateral toes on both sides contract. Specifically, the middle toe remains fixed. When the supporting palm is lifted, the leg link B (62) is subjected to downward pressure, and the slider (53) on the middle toe moves forward under the thrust of the leg link B (62). The foot link A (52) and foot link B (54) are connected to the lateral toe I (57) and the lateral toe II (56) respectively. The forward movement of the slider drives the foot link A (52) and the foot link B (54) to move the lateral toe I (57) and the lateral toe II (56) forward. 57) and lateral toe II (56) contract inward in a planar fixed-point circular motion, and the lateral toe as a whole is in a contraction motion; the middle toe (55) is fixed and when the supporting palm falls, the leg link B (62) is subjected to an upward pulling force, and the slider (53) on the middle toe moves backward under the pulling force of the leg link B (62), moving along the trajectory opposite to the lifting process; the slider drives the foot link A (52) and foot link B (54) to make the toe open outward in a planar fixed-point circular motion, and the lateral toe as a whole is in an extension motion.