CN117963038B - Rigid-flexible coupling bionic mechanical foot with buffering and anti-sinking functions - Google Patents

Abstract

The invention discloses a rigid-flexible coupling bionic mechanical foot with buffering and anti-sinking functions, belonging to the technical field of bionic robots, comprising an installation interface module, a ground contact and pressing module, a sand fixation and current limiting module and an anti-skid buffer module; the installation interface module is fixedly connected to the upper end of a bracket pressing plate, the bracket pressing plate has three guide holes in its no-load area, the left and right sides of the bottom of the bracket pressing plate are symmetrically rotatably connected with side connecting rods and a front connecting rod through small cylindrical pins, the lower ends of the two side connecting rods are both rotatably connected with side foot soles through small cylindrical pins, and the lower ends of the two front connecting rods are respectively rotatably connected with left flippers and right flippers through small cylindrical pins; when the robot lands, the bionic mechanical foot can gather and press the loose sand base to avoid sinking and slipping of the bionic mechanical foot; after the robot lifts its leg, the bracket pressing plate can automatically move upward to drive the left flipper, the right flipper and the side foot soles to reset, the fluidity of the sand is restored, and the bionic mechanical foot can smoothly leave the ground.

Description

A rigid-flexible coupling bionic mechanical foot with buffering and anti-sinking functions

Technical Field

The invention belongs to the technical field of bionic robots, and in particular relates to a rigid-flexible coupling bionic mechanical foot with buffering and anti-sinking functions.

Background technique

In the field of bionic robots, land bionic robots are one of its important branches. According to their movement mode, they can be mainly divided into three categories: wheeled robots, tracked robots, and legged robots. Among them, bionic legged robots are widely studied and applied due to their high flexibility and adaptability, and the mechanical feet in contact with the ground are the key factor for legged robots to adapt to the above different scenarios.

The mechanical feet of bionic leg-foot robots have been developed in various forms, mainly divided into flat feet, curved feet and spherical feet. However, the structure and function of such mechanical feet are relatively simple, and they are more suitable for walking on hard surfaces. They are less effective on soft surfaces such as sand, and are prone to problems such as sinking too deep, slipping, difficulty in moving, and slow movement. Especially for more flexible jumping robots, due to their greater impact force when landing, the above problems are more likely to occur, which seriously restricts their application on soft surfaces such as sand.

At present, there are few studies on mechanical feet for soft sandy environments at home and abroad, and some existing mechanical foot structural designs still find it difficult to integrate functions such as cushioning and shock absorption, stable walking, and smooth foot movement. From the perspective of bionics, through the study of the feet of some typical sandy animals, some inspiration can be provided for the design of bionic mechanical feet.

Summary of the invention

The present invention provides a rigid-flexible coupling bionic mechanical foot with buffering and anti-sinking functions. The technical problem to be solved is to prevent the mechanical foot from sinking too deeply, having difficulty in moving out, vibrating violently and slipping on the sand, thereby enabling the leg-foot robot to move smoothly and flexibly on the soft sand.

The design of the present invention couples a variety of biological coupling elements, including the camel's paw structure, the jerboa's toe structure, the sand lizard's paw scale structure, the cat's foot pad structure, etc. According to the structural or functional characteristics of the above biological coupling elements, a rigid-flexible coupling bionic mechanical foot with cushioning and anti-sinking functions is designed.

A rigid-flexible coupling bionic mechanical foot with buffering and anti-sinking functions, comprising an installation interface module, a ground contact and compression module, a sand fixation and current limiting module, and an anti-slip buffer module;

The ground contact clamping module includes a bracket clamping plate, a side connecting rod and a front connecting rod;

The installation interface module is fixedly connected to the upper end of the bracket pressure plate, and the bracket pressure plate has three guide holes in its no-load area. The left and right sides of the bottom of the bracket pressure plate are symmetrically connected to the side connecting rods and the front connecting rod through small cylindrical pins. The lower ends of the two side connecting rods are both rotatably connected to the side foot soles through small cylindrical pins, and the lower ends of the two front connecting rods are respectively rotatably connected to the left flipper and the right flipper through small cylindrical pins.

The sand-fixing and current-limiting module includes a reset spring, a foot sole plate, a side foot sole plate, a slider, a screw, a left flipper, a fixed toe plate, a right flipper, a small cylindrical pin, a large cylindrical pin, and a small spring;

Three guide shafts are provided at the upper end of the plantar plate, and the upper ends of the three guide shafts are respectively slidably connected to the three guide holes of the bracket pressure plate, and three return springs are respectively sleeved on the outside of the three guide shafts, and the upper and lower ends of the return springs are respectively connected to the bracket pressure plate and the plantar plate, and the two side surfaces of the plantar plate are rotatably connected to the two side plantar plates through large cylindrical pins, and the bottom surface of the side plantar plates has an array of three-dimensional scaly inclined structures, and the front end of the plantar plate is located between the left flipper and the right flipper and is fixedly connected with a fixed toe plate, and two sliding grooves are symmetrically opened at the front end of the plantar plate, and small springs are placed inside the sliding grooves, and the slider is slidably connected inside the sliding groove and one end of the slider is connected to the small spring, one slider is fixedly connected to the small cylindrical pin connected between the front connecting rod and the left flipper through a screw, and the other slider is fixedly connected to the small cylindrical pin connected between the front connecting rod and the right flipper through a screw, and the anti-slip buffer module is arranged on the lower surface of the plantar plate.

Preferably, the lower end of the bracket pressure plate is an inverted trapezoidal structure, which adopts a lightweight design, and the inner diameter of the guide hole is the same as the diameter of the guide shaft on the sole plate.

Preferably, the mounting support is a hollow cylindrical structure with positioning pin holes on its side. The mounting support can be connected to the robot leg mechanism and fixed through the side positioning pin holes.

Preferably, the side plantar plate is an elongated rectangular structure, the length of which is the same as the side of the plantar plate, and the side plantar plate is tilted downward at 45° with respect to the horizontal plane.

Preferably, the three-dimensional scaly inclined surface structure is a biological coupling element structure imitating the lamellar scales of the sole of the sand lizard, which has the function of increasing friction and assisting in sand fixation and flow limiting effect; the plane shape of the three-dimensional scaly inclined surface structure is a quadratic parabolic curve obtained by fitting the surface curve of the sand lizard scale, and the three-dimensional scaly inclined surface structure is an oblique cone with thickness formed by the quadratic parabolic curve; x represents the abscissa and y represents the ordinate, then the quadratic parabolic curve equation is:

y = 0.215 x ² +0.43 x +2; where: 2≤ x ≤4.

Preferably, the design of the left and right flippers imitates the function of the three toes of a jerboa contracting and fixing the sand when the jerboa's feet fall into the sand: when the jerboa's feet touch the ground, the toes on both sides of the three toes will press the sand towards the middle, thereby compacting the sand, and the left and right flippers of the bionic mechanical foot press the sand towards the fixed toe plate in the same way when they fall into the sand; the left and right flippers are round shovel-shaped structures, with an extended sharp surface at the lower end and a wrapped thin-walled structure on the side, which can increase the volume of the fixed sand and enhance the sand-fixing and flow-limiting effects.

Preferably, the anti-slip buffer module includes a sole pad and a heel pad. The structural shape of the sole pad is an elliptical curved surface structure; the structural shape of the heel pad is a symmetrical curved convex structure. Both the sole pad and the heel pad are made of rubber material and are respectively fixed to the front and rear ends of the bottom surface of the plantar plate by glue.

Preferably, the mounting interface module includes a mounting support, and the mounting support is connected to the upper end of the bracket pressure plate through a connecting bolt and a fixing nut.

The beneficial effects of the present invention are:

The present invention mainly utilizes the downward pressure and upward force of the legs of the leg-footed robot as a power source when the robot moves, and realizes the automatic compression and resetting of the bionic mechanical feet without adding other active parts; when the robot lands, the bionic mechanical feet can buffer the reaction force of the ground, and at the same time can gather and compress the loose sand base, which can prevent the bionic mechanical feet from sinking and slipping, thereby improving the robot's grip and stability; after the robot lifts its legs, the support pressure plate can automatically move upward to drive the left and right flippers and the side foot soles to reset, the fluidity of the sand is restored, and the bionic mechanical feet can smoothly leave the ground;

The feet of existing leg-and-foot robots are mostly flat feet, curved feet and spherical feet, which make it difficult for them to move smoothly on soft surfaces such as sand. The present invention is based on the biological coupling characteristics of multiple sand animals and cats, and designs a bionic mechanical foot with the ability to automatically compress and tighten the sand when it touches the ground, autonomously alleviate the impact force of the ground, have a high friction coefficient and are not easy to slip, and automatically loosen before leaving the ground to smoothly get out of the sand without affecting leg lifting. The overall mechanism is light in weight, simple in structure, and the sand-crossing process is simple. Without introducing new active parts, the mobility of leg-and-foot robots on soft surfaces such as sand is significantly improved.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is an overall structural diagram of the present invention;

Fig. 2 is a front view of the present invention;

Fig. 3 is a bottom view of the present invention;

FIG4 is a diagram of the overall structure of the present invention when it is compacted after touching the ground;

FIG5 is a front view of the present invention when it is pressed after touching the ground;

FIG6 is a front view of a three-dimensional scale-like inclined surface structure;

FIG. 7 is a bottom view of a three-dimensional scale-like inclined surface structure.

Among them: 1. Mounting support; 2. Connecting bolt; 3. Fixing nut; 4. Bracket pressure plate; 5. Reset spring; 6. Side connecting rod; 7. Plantar plate; 8. Side plantar plate; 9. Slider; 10. Screw; 11. Left flipper; 12. Fixed toe plate; 13. Right flipper; 14. Front connecting rod; 15. Small cylindrical pin; 16. Large cylindrical pin; 17. Small spring; 18. Sole pad; 19. Heel pad.

Detailed ways

Referring to FIGS. 1 to 7 , a rigid-flexible coupling bionic mechanical foot with buffering and anti-sinking functions includes an installation interface module, a ground contact and compression module, a sand fixation and current limiting module, and an anti-slip buffer module;

The installation interface module is the connection link between the robot leg and the bionic mechanical foot;

When the ground contact and clamping module is subjected to the downward pressure of the robot's legs, it starts to clamp under the action of the ground support force;

When the sand-fixing and flow-limiting module is subjected to compression force, it will drive the sand at the bottom to gather, limit the fluidity of the sand, and compact the loose sand base to enhance its passability;

The anti-skid buffer module can reduce the impact force of the ground when the bionic mechanical foot lands. Its special curved shape and arrangement can increase the friction of the sole plate 7 and enhance the grip of the bionic mechanical foot.

The ground contact clamping module includes a bracket clamping plate 4, a side connecting rod 6 and a front connecting rod 14;

The mounting interface module is fixedly connected to the upper end of the bracket pressing plate 4. The bracket pressing plate 4 has three guide holes in its no-load area. The left and right sides of the bottom of the bracket pressing plate 4 are symmetrically connected to the side connecting rods 6 and the front connecting rods 14 through small cylindrical pins 15. The lower ends of the two side connecting rods 6 are both connected to the side foot soles 8 through small cylindrical pins 15. The lower ends of the two front connecting rods 14 are respectively connected to the left flipper 11 and the right flipper 13 through small cylindrical pins 15.

The sand-fixing and current-limiting module includes a reset spring 5, a foot sole plate 7, a side foot sole plate 8, a slider 9, a screw 10, a left flipper 11, a fixed toe plate 12, a right flipper 13, a small cylindrical pin 15, a large cylindrical pin 16, and a small spring 17;

Three guide shafts are provided at the upper end of the plantar plate 7, and the upper ends of the three guide shafts are respectively slidably connected to the three guide holes of the bracket pressure plate 4, and three return springs 5 are respectively sleeved on the outside of the three guide shafts, and the upper and lower ends of the return springs 5 are respectively connected to the bracket pressure plate 4 and the plantar plate 7, and the cooperation of the guide shafts and the guide holes can ensure that the bracket pressure plate 4 moves in the vertical direction; the two side surfaces of the plantar plate 7 are rotatably connected to the two side plantar plates 8 through large cylindrical pins 16, and the bottom surface of the side plantar plates 8 has an array of three-dimensional scaly inclined structures, and the front end of the plantar plate 7 is fixedly connected between the left flipper 11 and the right flipper 13. A fixed toe plate 12 is provided, and two slide grooves are symmetrically provided at the front end of the plantar plate 7, and small springs 17 are placed inside the slide grooves. A slider 9 is slidably connected inside the slide groove and one end of the slider 9 is connected to the small spring 17. One slider 9 is fixedly connected to a small cylindrical pin 15 connected between a front connecting rod 14 and a left flipper 11 through a screw 10, and another slider 9 is fixedly connected to a small cylindrical pin 15 connected between a front connecting rod 14 and a right flipper 13 through a screw 10. The slide groove can limit the moving range of the slider 9 to ensure that it only slides in the horizontal direction and resets in time. The anti-skid buffer module is arranged on the lower surface of the plantar plate 7.

1 to 3 , preferably, the lower end of the bracket pressing plate 4 is an inverted trapezoidal structure, which adopts a lightweight design, and the inner diameter of the guide hole is the same as the diameter of the guide shaft on the sole plate 7 .

Referring to FIG. 1 , preferably, the mounting support 1 is a hollow cylindrical structure with positioning pin holes on its side. The mounting support 1 can be connected to the robot leg mechanism and fixed via the side positioning pin holes.

Referring to Figure 4, preferably, the structure of the side plantar plate 8 is a narrow and long rectangular structure similar to the two sides of the soles of sand lizards and jerboas, and its length is the same as the side of the plantar plate 7, which can enhance the role of the bionic mechanical foot in fixing sand and limiting flow. The side plantar plate 8 is set to be tilted downward at 45° with respect to the horizontal plane.

Referring to Figures 5 to 7, preferably, the three-dimensional scaly inclined surface structure is a biological coupling element structure imitating the lamellar scales of the sand lizard's feet, which has the effect of increasing friction and assisting in sand fixation and flow limiting effects; the plane shape of the three-dimensional scaly inclined surface structure is a quadratic parabolic curve obtained by fitting the surface curve of the sand lizard scales, and the three-dimensional scaly inclined surface structure is an oblique cone with a certain thickness formed by the quadratic parabolic curve; x represents the abscissa (parallel to the long side direction of the side foot plantar plate 8), and y represents the ordinate (parallel to the narrow side direction of the side foot plantar plate 8), then the quadratic parabolic curve equation is:

y = 0.215 x ² +0.43 x +2; where: 2≤ x ≤4.

Referring to Figures 1, 4 and 5, preferably, the design of the left web 11 and the right web 13 imitates the function of the three toes of a jerboa contracting and fixing the sand when they fall into the sand: when the jerboa's foot touches the ground, the toes on both sides of the three toes will press the sand towards the middle to compact the sand, and the bionic mechanical foot left web 11 and the right web 13 will press the sand towards the fixed toe plate 12 in the same way when they fall into the sand; the left web 11 and the right web 13 are round shovel-shaped structures, with their lower ends being extended sharp surfaces and the sides being wrapped thin-walled structures, which can increase the volume of the sand fixation and enhance the sand fixation and flow limiting effects.

Referring to FIG. 1 and FIG. 3 , preferably, the anti-skid buffer module includes a sole pad 18 and a heel pad 19. The sole pad 18 is an elliptical curved surface structure obtained by rubbing analysis and fitting of the front curved surface of the sole of a feline animal; the heel pad 19 is a symmetrical curved convex hull, which is a structural and functional bionics of the biological coupling element of the heel pad of a feline animal. A set of irregular curves is obtained by fitting analysis of the edge of the heel pad of a feline animal, and after combining them, a heel pad 19 with a "convex" curve structure is obtained; the sole pad 18 and the heel pad 19 are both made of rubber materials with certain elasticity and ductility, and are respectively fixed to the front and rear ends of the bottom surface of the sole plate 7 through colloid.

Referring to FIG. 1 , preferably, the mounting interface module comprises a mounting support 1 , and the mounting support 1 is connected to the upper end of the bracket pressing plate 4 through a connecting bolt 2 and a fixing nut 3 .

Working principle of the present invention:

When the leg-foot robot walks on the sand, the sole of the bionic mechanical foot touches the ground first when the leg lands, and the impact force of the ground is greatly reduced by the cushioning of the sole pad 18 and the heel pad 19. At the same time, the curved surface shape and special arrangement of the sole pad 18 and the heel pad 19 also increase the friction of the sole plate 7, thereby improving the grip of the bionic mechanical foot. After landing, the sole plate 7 stops moving downward, and drives the left flipper 11, the right flipper 13 and the side sole plate 8 to move by compressing the reset spring 5.

The left fin 11 and the right fin 13 move toward the middle of the sole plate 7 along the slide groove, and shovel the sand toward the fixed toe plate 12 through the shovel-shaped covering structure; the side sole plate 8 drives the sand toward the inner side of the sole through the three-dimensional scale-like inclined surface structure on its bottom surface, so that the bionic mechanical foot can press the loose sand base, avoiding the sinking and slipping of the bionic mechanical foot;

After the leg-type robot lifts its legs, the downward pressure disappears, and the legs generate an upward force on the bionic mechanical foot. Under the action of the reset spring 5, the auxiliary bracket pressure plate 4 moves upward faster and resets, and the left flipper 11, the right flipper 13 and the side foot sole 8 also return to the horizontal position to complete automatic reset; the pressure of the bionic mechanical foot on the loose sand base simultaneously subsides, the sand begins to disperse, and the fluidity of the sand is restored, so the bionic mechanical foot can smoothly get out of the sand and leave the ground.

Referring to Figures 5 and 6, the bottom surface of the side foot plantar plate 8 has an array of three-dimensional scaly inclined structures, which imitates the layered scale bio-coupling structure of the sand lizard's paw; the structure is arranged in an array on the bottom surface of the side foot plantar plate 8, and it is a small concave inclined surface, which has the function of increasing friction to assist sand fixation and flow limiting effects, and its planar structure is shown in Figure 7.

The embodiments described above only represent implementation methods of the invention. The protection scope of the present invention is not limited to the embodiments described above. For those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims (8)

1. A rigid-flexible coupling bionic mechanical foot with buffering and anti-sinking functions, characterized by comprising an installation interface module, a ground contact and compression module, a sand fixation and current limiting module, and an anti-slip buffer module; The ground contact clamping module comprises a bracket clamping plate (4), a side connecting rod (6) and a front connecting rod (14); The mounting interface module is fixedly connected to the upper end of the bracket pressure plate (4); the bracket pressure plate (4) has three guide holes in its no-load area; the left and right sides of the bottom of the bracket pressure plate (4) are symmetrically rotatably connected to the side connecting rods (6) and the front connecting rods (14) through small cylindrical pins (15); the lower ends of the two side connecting rods (6) are rotatably connected to the side foot sole plates (8) through small cylindrical pins (15); and the lower ends of the two front connecting rods (14) are rotatably connected to the left flipper (11) and the right flipper (13) respectively through small cylindrical pins (15); The sand-fixing and current-limiting module comprises a reset spring (5), a foot sole plate (7), a side foot sole plate (8), a slider (9), a screw rod (10), a left flipper (11), a fixed toe plate (12), a right flipper (13), a small cylindrical pin (15), a large cylindrical pin (16), and a small spring (17); The upper end of the sole plate (7) is provided with three guide shafts, and the upper ends of the three guide shafts are respectively slidably connected to the three guide holes of the bracket pressure plate (4). Three return springs (5) are respectively sleeved on the outside of the three guide shafts, and the upper and lower ends of the return springs (5) are respectively connected to the bracket pressure plate (4) and the sole plate (7). The two side surfaces of the sole plate (7) are rotatably connected to the two side sole plates (8) through large cylindrical pins (16). The bottom surface of the side sole plate (8) has an array of three-dimensional scale-like inclined surface structures. The front end of the sole plate (7) is fixedly connected between the left flipper (11) and the right flipper (13). A toe plate (12) is provided, and two slide grooves are symmetrically provided at the front end of the sole plate (7), and small springs (17) are placed inside the slide grooves. A slider (9) is slidably connected inside the slide groove, and one end of the slider (9) is connected to the small spring (17). One slider (9) is fixedly connected to a small cylindrical pin (15) connected between a front connecting rod (14) and a left flipper (11) through a screw rod (10), and the other slider (9) is fixedly connected to a small cylindrical pin (15) connected between a front connecting rod (14) and a right flipper (13) through a screw rod (10). An anti-skid buffer module is arranged on the lower surface of the sole plate (7). 2. A rigid-flexible coupling bionic mechanical foot with buffering and anti-sinking functions according to claim 1, characterized in that: the lower end of the support pressure plate (4) is an inverted trapezoidal structure, and the inner diameter of the guide hole is the same as the diameter of the guide shaft on the sole plate (7). 3. According to claim 2, a rigid-flexible coupling bionic mechanical foot with buffering and anti-sinking functions is characterized in that: the mounting support (1) is a hollow cylindrical structure, and a positioning pin hole is provided on its side. The mounting support (1) can be connected to the robot leg mechanism and fixed through the side positioning pin hole. 4. A rigid-flexible coupling bionic mechanical foot with cushioning and anti-sinking functions according to claim 3, characterized in that: the side plantar plate (8) is a long rectangular structure, the length of which is the same as the side of the plantar plate (7), and the side plantar plate (8) is set to be inclined downward by 45° with respect to the horizontal plane. 5. According to claim 1, a rigid-flexible coupling bionic mechanical foot with buffering and anti-sinking functions is characterized in that: the plane shape of the three-dimensional scaly inclined surface structure is a quadratic parabolic curve obtained by fitting the surface curve of the sand lizard scales, and the three-dimensional scaly inclined surface structure is an oblique cone with thickness formed by the quadratic parabolic curve; x represents the abscissa and y represents the ordinate, then the quadratic parabolic curve equation is: y = 0.215 x ² +0.43 x +2; where: 2≤ x ≤4. 6. A rigid-flexible coupling bionic mechanical foot with cushioning and anti-sinking functions according to claim 1, characterized in that: the left flipper (11) and the right flipper (13) are round shovel-shaped structures, the lower ends of which are extended sharp surfaces, and the side surfaces are wrapped thin-walled structures. 7. A rigid-flexible coupling bionic mechanical foot with cushioning and anti-sinking functions according to claim 1, characterized in that: the anti-slip cushioning module includes a sole pad (18) and a heel pad (19), the structural shape of the sole pad (18) is an elliptical curved surface structure; the structural shape of the heel pad (19) is a symmetrical curved surface convex hull, the sole pad (18) and the heel pad (19) are both made of rubber material, and are respectively fixed to the front end and the rear end of the bottom surface of the sole plate (7) by glue. 8. A rigid-flexible coupling bionic mechanical foot with buffering and anti-sinking functions according to claim 1, characterized in that: the mounting interface module comprises a mounting support (1), and the mounting support (1) is connected to the upper end of the bracket pressure plate (4) through a connecting bolt (2) and a fixing nut (3).