A multi-legged walking platform with variable stiffness joints

Abstract

A variable-stiffness joint multi-leg walking platform comprises identical left front, left rear, right rear, and right front leg mechanisms (A, B, C, D), a trunk (E), and push rods (F). Specifically, the platform is a highly maneuverable closed-chain leg-type walking platform with two joint stiffness modes. Each leg mechanism is driven by a motor. A push rod rotating connector (F‑3) in the left push rod mechanism (F) is fixedly connected to a push rod long connector (A‑1‑1) in a variable-stiffness joint (A‑1) via bolts. During operation of the push rods, a speed difference is achieved via two first thigh rods (A‑2‑1) and gears 1 (A‑1‑5), 2 (A‑1‑6), and 3 (A‑1‑7), thereby completing the conversion between joint stiffness and flexibility. Compared to existing walking platforms, the platform's terrain adaptability can be improved by varying joint stiffness. While reconstructing vibration reduction in the pitch state, energy loss caused by inconsistent traction speeds in the front and rear legs can be reduced.

Description

Technical Field

[0001] The present invention relates to a multi-legged walking platform with variable stiffness joints, specifically a highly maneuverable closed-chain leg-type walking platform with two joint stiffness modes and multiple gaits. The joint stiffness has two modes, rigid and flexible. The degree of flexibility is controlled by changes in the joints. Different gaits are obtained in different stiffness modes to reduce the internal energy consumption caused by the inconsistent speed of the front and rear legs in the pitch obstacle crossing state, and the platform has terrain adaptability. Background Art

[0002] The closed kinematic chain is applied to the leg mechanism of the walking platform, and each leg mechanism is driven by an independent motor. Compared with the open chain leg, under the conditions of the same material, external load and speed level, the closed chain rod system theoretically only bears tensile and compressive loads.

[0003] Chinese patent CN118343226A discloses "an omnidirectional trunk-reconfigurable multi-leg platform," which includes: identical left front, right front, left rear, and right rear leg mechanisms (A, B, C, D) and a trunk (E); the shape and geometric parameters of the rods in the trunk (E) are set to make the trunk (E) a two-degree-of-freedom spatial mechanism with three deformation modes. In the three deformation modes, the omnidirectional trunk-reconfigurable multi-leg platform can respectively achieve three different gaits: pitch, waist tuck, and omnidirectional, with high terrain adaptability and high maneuverability.

[0004] Chinese patent CN110091934A discloses an "adaptive multi-legged walking platform," comprising four identical first to fourth leg mechanisms (A, B, C, and D) and a frame (E). The thigh lever is a variable-parameter lever. The timing of the thigh lever's locking and release is controlled by a cam mechanism coupled to a drive crank, enabling passive terrain adaptation, enabling transportation and surveying tasks on complex terrain, such as mountainous terrain. Summary of the Invention

[0005] The present invention aims to provide a walking platform that, compared to existing walking platforms, improves terrain adaptability by varying joint stiffness. This reduces vibration during pitch and roll, while also minimizing energy loss caused by inconsistent traction speeds between the front and rear legs. The joints have two stiffness modes: a rigid mode suitable for flat or smooth surfaces, and a flexible mode suitable for steps and other types of uneven surfaces. Combining these two modes improves adaptability to complex surfaces.

[0006] The technical solution of the present invention:

[0007] A variable-stiffness joint multi-leg walking platform comprises identical left front, right front, left rear, and right rear leg mechanisms and a trunk. The left front and right front leg mechanisms and the left rear and right rear leg mechanisms are arranged counterclockwise in the order of left front leg mechanism, left rear leg mechanism, right rear leg mechanism, and right front leg mechanism. The left front, left rear, right rear, and right front leg mechanisms of the variable-stiffness joint multi-leg walking platform are all driven by a single motor. The left front leg mechanism is fixedly connected to the left front trunk; the left rear leg mechanism is fixedly connected to the left rear trunk; the right rear leg mechanism is fixedly connected to the right rear trunk; and the right front leg mechanism is fixedly connected to the trunk. The left front and right front leg mechanisms are fixedly connected to the push rod rotating connector of the left push rod mechanism via bolts; and the left push rod mechanism is rotationally connected to the trunk via an assembly shaft.

[0008] The rod shapes, mechanical structures and assembly methods of the left front leg mechanism, left rear leg mechanism, right rear leg mechanism and right front leg mechanism are exactly the same; the left front leg mechanism, right front leg mechanism and the left rear leg mechanism, right rear leg mechanism are mirror-arranged with respect to the transverse symmetry plane of the variable stiffness joint multi-legged walking platform; the left front leg mechanism, left rear leg mechanism and the right rear leg mechanism, right front leg mechanism are mirror-arranged with respect to the longitudinal symmetry plane of the variable stiffness joint multi-legged walking platform; the rod shapes, mechanical structures and assembly methods of the left push rod mechanism and the right push rod mechanism are exactly the same, and are mirror-arranged with respect to the longitudinal symmetry plane of the variable stiffness joint multi-legged walking platform.

[0009] Through the above connection, the variable stiffness joint multi-legged walking platform is assembled; the push rod rotating connector in the left push rod mechanism and the push rod long connector in the variable stiffness joint are fixedly connected by bolts; during the working stroke of the push rod, the speed difference is achieved through the two first thigh rods and gears 1, 2, and 3, thereby completing the conversion of joint rigidity and flexibility.

[0010] The left front leg mechanism is composed of a rear variable stiffness joint part, a rear leg group connecting rod part, a power driving part, a front leg group connecting rod part, a front variable stiffness joint part and a baffle.

[0011] The connection method of the components in the left front leg mechanism is as follows: the rear variable stiffness joint and the rear leg group connecting rod part are rotationally connected through an assembly axis; the rear variable stiffness joint part and the baffle are rotationally connected through an assembly axis; the rear leg group connecting rod part (and the power drive part are rotationally connected through an assembly axis; the rear leg group connecting rod part and the power drive part are fixedly connected to the baffle through bolts; the rod shape, mechanical structure and assembly method of the front leg group connecting rod part and the rear leg group connecting rod part are exactly the same, and are longitudinally symmetrical with respect to the left front leg mechanism; the rod shape, mechanical structure and assembly method of the front variable stiffness joint part and the rear variable stiffness joint part are exactly the same, and are longitudinally symmetrical with respect to the left front leg mechanism.

[0012] The rear variable stiffness joint is composed of a long push rod connector, a short push rod connector, a spring, a limit rod 1, a gear 1, a gear 2, a gear 3, a short transmission rod, a long transmission rod, a limit rod 2, a connecting rod, a rear mounting shaft, and a front mounting shaft.

[0013] The connection method of the components in the rear variable stiffness joint is as follows: the long push rod connector and the short push rod connector are fixedly connected by bolts; the long push rod connector and the push rod rotating connector are fixedly connected by bolts; the bottom mounting hole of the long push rod connector and the middle mounting hole of the connecting rod are flexibly connected by a spring; the short push rod connector and the limit rod 1 are fixedly connected by bolts; the bottom mounting hole of the limit rod 1, gear 1 and the rear mounting shaft are connected by key fitting; the bottom mounting hole of the limit rod 2, the bottom mounting hole of the connecting rod, the rear mounting hole of the baffle and the rear mounting shaft are rotationally connected; gear 1, gear 2, and gear 3 are meshed and connected; gear 3 and the transmission short rod are fixedly connected by the front mounting shaft key fitting; the front mounting hole of the baffle is rotationally connected to the front mounting shaft; the upper mounting hole of the transmission short rod and the bottom mounting hole of the transmission long rod are rotationally connected by bolts; the upper mounting hole of the transmission long rod and the upper mounting hole of the limit rod 2 are rotationally connected by bolts.

[0014] The rod shape, mechanical structure and assembly method of the front variable stiffness joint part and the rear variable stiffness joint part are exactly the same, and are longitudinally symmetrical about the left front leg mechanism.

[0015] The rear leg group connecting rod part includes: two first thigh rods, a first third auxiliary rod, a first straight rod, a first calf rod, a second calf rod, a second straight rod, a plug bolt, a second third auxiliary rod, two second thigh rods, and a base.

[0016] The connection method of the components in the connecting rod part of the rear leg group is as follows: the first and second thigh rods are three-pronged rods, and mounting holes are arranged at the upper, bottom and middle positions; the first three-pronged rods and the second three-pronged rods are three-pronged rods, and mounting holes are arranged at the three top angle positions; the two first thigh rod long end mounting holes and the upper mounting holes of the connecting rod are rotatably connected through an assembly shaft; the two first thigh rod middle mounting holes and the first three-pronged rod long end mounting holes are rotatably connected through an assembly shaft; the two first straight rod end mounting holes and the first three-pronged rod short end bottom mounting holes are rotatably connected through an assembly shaft; the two first thigh rod bottom mounting holes and the first calf rod upper mounting holes are rotatably connected through an assembly shaft; the two first straight rod other end mounting holes and the first calf rod middle mounting holes are rotatably connected through an assembly shaft; the first The upper mounting hole of the short end of the third auxiliary rod and the upper mounting hole of the short end of the second third auxiliary rod are rotatably connected by plug bolts; the upper mounting holes of the two second thigh rods and the bottom mounting hole of the base are rotatably connected by an assembly shaft; the middle mounting holes of the two second thigh rods and the long end mounting holes of the second third auxiliary rod are rotatably connected by an assembly shaft; the end mounting holes of the two second straight rods and the bottom mounting holes of the short end of the second third auxiliary rod are rotatably connected by an assembly shaft; the bottom mounting holes of the short end of the two second thigh rods and the upper mounting holes of the second calf rod are rotatably connected by an assembly shaft; the other end mounting holes of the two second straight rods and the middle mounting holes of the second calf rod are rotatably connected by an assembly shaft; the mounting holes are arranged at four right angles to the base and the axial direction is vertical; and they are fixedly connected to the base and the left front bottom plate.

[0017] The rod shape, mechanical structure and assembly method of the front leg group connecting rod part and the rear leg group connecting rod part are exactly the same, and are longitudinally symmetrical about the left front leg mechanism.

[0018] The power driving part is composed of a brushless DC motor, a right crank, a right leg group connecting piece, a left leg group connecting piece, a left crank, and a reducer.

[0019] The connection method of the components in the power drive unit is as follows: four mounting holes are evenly arranged on the end surface of the left leg group connector; the DC brushless motor, the right leg group connector, the left leg group connector, and the reducer are fixedly connected by bolts; the reducer and the right crank are rotationally connected through the assembly shaft; the reducer and the left crank are rotationally connected through the assembly shaft; the left leg group connector and the right leg group connector are symmetrically arranged about the motor axis; the phase difference between the left crank and the right crank is 180°; the DC brushless motor drives the left crank and the right crank to rotate a full circle to realize the walking movement of the left front leg mechanism.

[0020] The trunk consists of a left front trunk, a left rear trunk, a right rear trunk, a right front trunk, a trunk long connector, a trunk short connector, a left push rod bent connector, a right push rod bent connector, and a trunk connector.

[0021] The connection method of the torso parts is as follows: the left front torso and the right front torso are fixedly connected to the two ends of the torso long connecting piece respectively; the left front torso and the left rear torso are fixedly connected to the two ends of the torso short connecting piece respectively; the torso connecting piece is fixedly connected to the left front torso, the left rear torso, the right rear torso and the right front torso respectively by bolts; the left push rod bent connecting piece and the right push rod bent connecting piece are fixedly connected to the torso connecting piece respectively by bolts.

[0022] The left front trunk is composed of a left front first long connector, a left front first transverse connector, a left front first short connector, a left front second long connector, a left front second transverse connector, a left front second transverse connector, a left front first short connector, and an adjusting gasket.

[0023] The connection method of the components in the left front torso is: in the left front torso, the left front first long connecting member and the left front second long connecting member are fixedly connected to the two ends of the left front first short connecting member and the left front second short connecting member respectively; the adjustment gasket is fixedly connected to the left front first long connecting member; the two ends of the left front first transverse connecting member and the left front second transverse connecting member are fixedly connected to the upper end of the adjustment gasket and the left front first long connecting member respectively; the left front first long connecting member is fixedly connected to the lower surface of the adjustment gasket.

[0024] The rod shapes, mechanical structures and assembly methods of the left front torso, left rear torso, right rear torso and right front torso in the torso are exactly the same; the left front torso, right front torso and left rear torso, right rear torso are mirror-arranged with respect to the transverse symmetry plane of the variable stiffness joint multi-legged walking platform; the left front torso, left rear torso and right front torso, right rear torso are mirror-arranged with respect to the longitudinal symmetry plane of the variable stiffness joint multi-legged walking platform.

[0025] The left push rod mechanism is composed of a push rod, a push rod connecting piece, and a push rod rotating connecting piece.

[0026] The connection method of the components in the left push rod mechanism is: the push rod and the push rod connecting piece are rotationally connected through the assembly shaft; the push rod connecting piece and the push rod rotating connecting piece are fixedly connected by bolts.

[0027] Beneficial effects of the present invention:

[0028] The present invention discloses a multi-legged walking platform with variable stiffness joints. This is a highly maneuverable closed-chain leg-type walking platform with two joint stiffness modes and multiple gaits. The joint stiffness has two modes: rigid and flexible. Changes in the joints control the degree of flexibility. In the rigid joint mode, the platform has high passability on flat roads. In the flexible mode, the platform has high vibration damping when navigating obstacles such as steps and potholes. Furthermore, the platform is reconfigurable, reducing the internal energy consumption caused by inconsistent traction speeds between the front and rear legs during pitch obstacle traversal. The two joint stiffness modes are switched according to the terrain, allowing different gaits to be achieved in different stiffness modes. The platform has high terrain adaptability, high passability, and high maneuverability. It can be used in fields such as detection, reconnaissance, and transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The overall three-dimensional image of the initial state of a multi-legged walking platform with variable stiffness joints

[0030] Figure 2 3D diagram of the left front leg mechanism

[0031] Figure 3 3D image of the variable stiffness joint

[0032] Figure 4 3D diagram of the leg group connecting rod

[0033] Figure 5 3D diagram of the power drive unit

[0034] Figure 6 3D image of the torso

[0035] Figure 7 3D image of the left front torso

[0036] Figure 8 3D diagram of the push rod mechanism DETAILED DESCRIPTION

[0037] The present invention will be further described below with reference to the accompanying drawings.

[0038] like Figure 1 As shown, a variable stiffness joint multi-leg walking platform is composed of identical left front, right front, left rear, and right rear leg mechanisms (A, B, C, D) and a trunk (E); the left front and right front leg mechanisms (A, B) and the left rear and right rear leg mechanisms (C, D) are arranged counterclockwise in the order of left front leg mechanism (A), left rear leg mechanism (B), right rear leg mechanism (C), and right front leg mechanism (D); the left front, left rear, right rear, and right front leg mechanisms (A, B, C, D) of the variable stiffness joint multi-leg walking platform are all driven by a single motor for walking. The left front leg mechanism (A) is fixedly connected to the left front torso (E-1); the left rear leg mechanism (B) is fixedly connected to the left rear torso (E-2); the right rear leg mechanism (C) is fixedly connected to the right rear torso (E-3); the right front leg mechanism (D) is fixedly connected to the torso (E-4); the left front and right front leg mechanisms (A, B) are fixedly connected to the push rod rotating connector (F-3) in the left push rod mechanism (F) by bolts; the left push rod mechanism (F) is rotationally connected to the torso (E) by an assembly shaft.

[0039] The rod shapes, mechanical structures and assembly methods of the left front leg mechanism (A), left hind leg mechanism (B), right hind leg mechanism (C) and right front leg mechanism (D) are exactly the same; the left front leg mechanism, right front leg mechanism (A, D) and the left hind leg mechanism, right hind leg mechanism (B, C) are mirror-arranged with respect to the transverse symmetry plane of the variable stiffness joint multi-legged walking platform; the left front leg mechanism, left hind leg mechanism (A, B) and the right hind leg mechanism, right front leg mechanism (C, D) are mirror-arranged with respect to the longitudinal symmetry plane of the variable stiffness joint multi-legged walking platform; the rod shapes, mechanical structures and assembly methods of the left push rod mechanism (F) and the right push rod mechanism (G) are exactly the same and are mirror-arranged with respect to the longitudinal symmetry plane of the variable stiffness joint multi-legged walking platform.

[0040] Through the above connection, the assembly of the variable stiffness joint multi-legged walking platform is completed; the push rod rotating connector (F-3) in the left push rod mechanism (F) and the push rod long connector (A-1-1) in the variable stiffness joint part (A-1) are fixedly connected by bolts; during the working stroke of the push rod, the speed difference is achieved through the two first thigh rods (A-2-1) and gear 1 (A-1-5), gear 2 (A-1-6), and gear 3 (A-1-7), thereby completing the conversion of joint rigidity and flexibility.

[0041] like Figure 2 As shown, the left front leg mechanism (A) is composed of a rear variable stiffness joint (A-1), a rear leg group connecting rod (A-2), a power drive unit (A-3), a front leg group connecting rod (A-4), a front variable stiffness joint (A-5) and a baffle (A-6);

[0042] The connection method of the components in the left front leg mechanism (A) is as follows: the rear variable stiffness joint part (A-1) and the rear leg group connecting rod part (A-2) are rotationally connected through an assembly axis; the rear variable stiffness joint part (A-1) and the baffle (A-6) are rotationally connected through an assembly axis; the rear leg group connecting rod part (A-2) and the power drive part (A-3) are rotationally connected through an assembly axis; the rear leg group connecting rod part (A-2) and the power drive part (A-3) are fixedly connected to the baffle (A-6) through bolts; the rod shape, mechanical structure and assembly method of the front leg group connecting rod part (A-4) and the rear leg group connecting rod part (A-2) are exactly the same, and are longitudinally symmetrical with respect to the left front leg mechanism (A); the rod shape, mechanical structure and assembly method of the front variable stiffness joint part (A-5) and the rear variable stiffness joint part (A-1) are exactly the same, and are longitudinally symmetrical with respect to the left front leg mechanism (A).

[0043] like Figure 3As shown, the rear variable stiffness joint part (A-1) is composed of a long push rod connector (A-1-1), a short push rod connector (A-1-2), a spring (A-1-3), a limit rod 1 (A-1-4), a gear 1 (A-1-5), a gear 2 (A-1-6), a gear 3 (A-1-7), a short transmission rod (A-1-8), a long transmission rod (A-1-9), a limit rod 2 (A-1-10), a connecting rod (A-1-11), a rear mounting shaft (A-1-12), and a front mounting shaft (A-1-13).

[0044] The connection method of the components in the rear variable stiffness joint (A-1) is as follows: the push rod long connector (A-1-1) and the push rod short connector (A-1-2) are fixedly connected by bolts; the push rod long connector (A-1-1) and the push rod rotating connector (F-3) are fixedly connected by bolts; the bottom mounting hole of the push rod long connector (A-1-1) and the middle mounting hole of the connecting rod (A-1-11) are flexibly connected by a spring (A-1-3); the push rod short connector (A-1-2) and the limit rod 1 (A-1-4) are fixedly connected by bolts; the bottom mounting hole of the limit rod 1 (A-1-4), the gear 1 (A-1-5) and the rear mounting shaft (A-1-12) are connected by key fit; the bottom mounting hole of the limit rod 2 (A-1-10), the connecting rod ( The bottom mounting hole of the baffle (A-1-11), the rear mounting hole of the baffle (A-6) and the rear mounting shaft (A-1-12) are rotationally connected; gear 1 (A-1-5), gear 2 (A-1-6) and gear 3 (A-1-7) are meshed and connected; gear 3 (A-1-7) and the transmission short rod (A-1-8) are fixedly connected through the front mounting key (A-1-13); the front mounting hole of the baffle (A-6) is rotationally connected to the front mounting shaft (A-1-13); the upper mounting hole of the transmission short rod (A-1-8) and the bottom mounting hole of the transmission long rod (A-1-9) are rotationally connected by bolts; the upper mounting hole of the transmission long rod (A-1-9) and the upper mounting hole of the limit rod 2 (A-1-10) are rotationally connected by bolts.

[0045] The rod shape, mechanical structure and assembly method of the front variable stiffness joint part (A-5) and the rear variable stiffness joint part (A-1) are exactly the same, and are longitudinally symmetrical about the left front leg mechanism (A).

[0046] like Figure 4 As shown, the rear leg group connecting rod part (A-2) includes: two first thigh rods (A-2-1), the first third auxiliary rod (A-2-2), the first straight rod (A-2-3), the first calf rod (A-2-4), the second calf rod (A-2-5), the second straight rod (A-2-6), the plug bolt (A-2-7), the second third auxiliary rod (A-2-8), two second thigh rods (A-2-9), and the base (A-2-10).

[0047] The connection method of the parts in the connecting rod part (A-2) of the rear leg group is as follows: the first and second thigh rods (A-2-1, A-2-9) are three-pair rods, and the mounting holes are arranged at the top, bottom and middle positions; the first third-pair rod and the second third-pair rod (A-2-2, A-2-8) are three-pair rods, and the mounting holes are arranged at the three top corner positions; the long end mounting holes of the two first thigh rods (A-2-1) are rotatably connected to the upper mounting holes of the connecting rod (A-1-11) through the assembly shaft; the middle mounting holes of the two first thigh rods (A-2-1) are connected to the first third-pair rod (A-1-11) through the assembly shaft. -2-2) long end mounting holes are rotatably connected via an assembly shaft; the end mounting holes of the two first straight rods (A-2-3) and the bottom mounting holes of the short ends of the first three auxiliary rods (A-2-2) are rotatably connected via an assembly shaft; the bottom mounting holes of the two first thigh rods (A-2-1) and the upper mounting holes of the first calf rod (A-2-4) are rotatably connected via an assembly shaft; the other end mounting holes of the two first straight rods (A-2-3) and the middle mounting holes of the first calf rod (A-2-4) are rotatably connected via an assembly shaft; the first three auxiliary rods (A- 2-2) The upper mounting hole of the short end is connected to the upper mounting hole of the short end of the second third auxiliary rod (A-2-8) by plugging bolts (A-2-7); the upper mounting holes of the two second thigh rods (A-2-9) are connected to the bottom mounting holes of the base (A-2-10) by assembly shafts; the middle mounting holes of the two second thigh rods (A-2-9) are connected to the long end mounting holes of the second third auxiliary rod (A-2-8) by assembly shafts; the end mounting holes of the two second straight rods (A-2-6) are connected to the short end mounting holes of the second third auxiliary rod (A-2-8) by assembly shafts. The bottom mounting holes at the ends are rotatably connected through an assembly shaft; the bottom mounting holes at the short ends of the two second thigh rods (A-2-9) and the upper mounting holes of the second calf rods (A-2-5) are rotatably connected through an assembly shaft; the mounting holes at the other ends of the two second straight rods (A-2-6) and the middle mounting holes of the second calf rods (A-2-5) are rotatably connected through an assembly shaft; the mounting holes are arranged at four right-angle positions of the base (A-2-10) and the axial direction is vertical; and the base (A-2-10) is fixedly connected to the left front bottom plate (E-1-1).

[0048] The rod shape, mechanical structure and assembly method of the front leg group connecting rod part (A-4) and the rear leg group connecting rod part (A-2) are exactly the same, and are longitudinally symmetrical about the left front leg mechanism (A).

[0049] like Figure 5 As shown, the power drive unit (A-3) is composed of a brushless DC motor (A-3-1), a right crank (A-3-2), a right leg group connector (A-3-3), a left leg group connector (A-3-4), a left crank (A-3-5), and a reducer (A-3-6).

[0050] The connection method of the components in the power drive unit (A-3) is as follows: four mounting holes are evenly arranged at the end surface of the left leg group connector (A-3-4); the DC brushless motor (A-3-1), the right leg group connector (A-3-3), the left leg group connector (A-3-4), and the reducer (A-3-6) are fixedly connected by bolts; the reducer (A-3-6) and the right crank (A-3-2) are rotationally connected through an assembly shaft; the reducer (A-3-6) It is rotationally connected to the left crank (A-3-5) through an assembly shaft; the left leg group connecting part (A-3-4) and the right leg group connecting part (A-3-3) are arranged symmetrically about the motor axis; the phase difference between the left crank (A-3-5) and the right crank (A-3-2) is 180°; the DC brushless motor (A-3-1) drives the left crank (A-3-5) and the right crank (A-3-2) to rotate a full circle, realizing the walking movement of the left front leg mechanism (A).

[0051] like Figure 6 As shown, the torso (E) is composed of a left front torso (E-1), a left rear torso (E-2), a right rear torso (E-3), a right front torso (E-4), a long torso connector (E-5), a short torso connector (E-6), a left push rod bend connector (E-7), a right push rod bend connector (E-8), and a torso connector (E-9).

[0052] The connection method of the parts in the torso (E) is as follows: the left front torso (E-1) and the right front torso (E-4) are fixedly connected to the two ends of the torso long connector (E-5) respectively; the left front torso (E-1) and the left rear torso (E-2) are fixedly connected to the two ends of the torso short connector (E-6) respectively; the torso connector (E-9) is fixedly connected to the left front torso (E-1), the left rear torso (E-2), the right rear torso (E-3), and the right front torso (E-4) respectively by bolts; the left push rod bent connector (E-7) and the right push rod bent connector (E-8) are fixedly connected to the torso connector (E-9) respectively by bolts.

[0053] like Figure 7 As shown, the left front torso (E-1) is composed of a left front first long connector (E-1-1), a left front first transverse connector (E-1-2), a left front first short connector (E-1-3), a left front second long connector (E-1-4), a left front second transverse connector (E-1-2), a left front second transverse connector (E-1-5), a left front first short connector (E-1-6), and an adjustment gasket (E-1-7).

[0054] The connection method of the components in the left front torso (E-1) is as follows: in the left front torso (E-1), the left front first long connecting member (E-1-1) and the left front second long connecting member (E-1-4) are fixedly connected to the two ends of the left front first short connecting member and the left front second short connecting member (E-1-3, E-1-6) respectively; the adjusting gasket (E-1-7) is fixedly connected to the left front first long connecting member (E-1-1); the two ends of the left front first transverse connecting member (E-1-2) and the left front second transverse connecting member (E-1-5) are fixedly connected to the upper end of the adjusting gasket (E-1-7) and the left front first long connecting member (E-1-4) respectively; the left front first long connecting member (E-1-1) is fixedly connected to the lower surface of the adjusting gasket (E-1-7).

[0055] The rod shapes, mechanical structures and assembly methods of the left front torso (E-1), left rear torso (E-2), right rear torso (E-3) and right front torso (E-4) in the torso (E) are exactly the same; the left front torso, right front torso (E-1, E-4) and the left rear torso, right rear torso (E-2, E-3) are mirror-arranged with respect to the transverse symmetry plane of the variable stiffness joint multi-legged walking platform; the left front torso, left rear torso (E-1, E-2) and the right front torso, right rear torso (E-4, E-3) are mirror-arranged with respect to the longitudinal symmetry plane of the variable stiffness joint multi-legged walking platform.

[0056] like Figure 8 As shown, the left push rod mechanism (F) is composed of a push rod (F-1), a push rod connecting member (F-2), and a push rod rotating connecting member (F-3).

[0057] The connection method of the components in the left push rod mechanism (F) is as follows: the push rod (F-1) and the push rod connector (F-2) are rotationally connected through an assembly shaft; the push rod connector (F-2) and the push rod rotation connector (F-3) are fixedly connected by bolts.

[0058] The variable stiffness is achieved by changing the differential rotation of the limit rod 1 (A-1-4) and the limit rod 2 (A-1-10), changing the connecting rod (A-1-11) to obtain a certain movement space. The specific implementation is as follows: When the multi-legged walking platform senses that it needs to cross an obstacle in front, the push rod (F) drives the limit rod 1 (A-1-4) to rotate, and the limit rod 1 (A-1-4) drives the gear 1 (A-1-5) to rotate through the key connection, and the gear 1 (A-1-5) drives the gear set gear 2 (A-1-6) and gear 3 (A-1-7) to realize differential transmission. Finally, the limit rod 2 (A-1-10) is rotated under the action of the differential through the connecting rod transmission of the front side mounting shaft (A-1-13), the transmission short rod (A-1-8), and the transmission long rod (A-1-9). Due to the differential rotation of rod 1 (A-1-4) and limit rod 2 (A-1-10), the connecting rod (A-1-11) obtains a certain movement space in the obstacle crossing mode and obtains a new degree of freedom. Since the connecting rod (A-1-11) is connected to the push rod long connector (A-1-1) through the spring (A-1-3), the movement of the connecting rod (A-1-11) is subject to mechanical constraints, realizing a flexible mode; when the push rod (F) is reset, the limit rod 1 (A-1-4) and the limit rod 2 (A-1-10) completely limit the movement space of the connecting rod (A-1-11), realizing a rigid mode.

Claims

1. A multi-legged walking platform with variable stiffness joints, characterized by: A variable stiffness joint multi-leg walking platform is composed of identical left front, right front, left rear, and right rear leg mechanisms (A, B, C, D) and a trunk (E); the left front and right front leg mechanisms (A, D) and the left rear and right rear leg mechanisms (B, C) are arranged at the four corners of the trunk (E) in the order of left front leg mechanism (A), left rear leg mechanism (B), right rear leg mechanism (C), and right front leg mechanism (D); the left front, left rear, right rear, and right front leg mechanisms (A, B, C, D) of the variable stiffness joint multi-leg walking platform are arranged at the four corners of the trunk (E) in the order of left front leg mechanism (A), left rear leg mechanism (B), right rear leg mechanism (C), and right front leg mechanism (D). ) are all driven by a single motor for walking; the left front leg mechanism (A) is fixedly connected to the left front torso (E-1); the left rear leg mechanism (B) is fixedly connected to the left rear torso (E-2); the right rear leg mechanism (C) is fixedly connected to the right rear torso (E-3); the right front leg mechanism (D) is fixedly connected to the torso (E-4); the left front and right front leg mechanisms (A, B) are fixedly connected to the push rod rotating connector (F-3) in the left push rod mechanism (F) by bolts; the left push rod mechanism (F) is rotationally connected to the torso (E) by an assembly shaft; The rod shape, mechanical structure and assembly method of the left front leg mechanism (A), the left hind leg mechanism (B), the right hind leg mechanism (C) and the right front leg mechanism (D) are exactly the same; the left front leg mechanism, the right front leg mechanism (A, D) and the left hind leg mechanism, the right hind leg mechanism (B, C) are mirror-arranged with respect to the transverse symmetry plane of the variable stiffness joint multi-legged walking platform; the left front leg mechanism, the left hind leg mechanism (A, B) and the right hind leg mechanism, the right front leg mechanism (C, D) are mirror-arranged with respect to the longitudinal symmetry plane of the variable stiffness joint multi-legged walking platform; the rod shape, mechanical structure and assembly method of the left push rod mechanism (F) and the right push rod mechanism (G) are exactly the same and are mirror-arranged with respect to the longitudinal symmetry plane of the variable stiffness joint multi-legged walking platform; Through the above connection, the assembly of the variable stiffness joint multi-legged walking platform is completed; the push rod rotating connector (F-3) in the left push rod mechanism (F) and the push rod long connector (A-1-1) in the variable stiffness joint part (A-1) are fixedly connected by bolts; during the working stroke of the push rod, the speed difference is achieved through the two first thigh rods (A-2-1) and gear 1 (A-1-5), gear 2 (A-1-6), and gear 3 (A-1-7), thereby completing the conversion of joint rigidity and flexibility. The left front leg mechanism (A) is composed of a rear variable stiffness joint (A-1), a rear leg group connecting rod (A-2), a power drive unit (A-3), a front leg group connecting rod (A-4), a front variable stiffness joint (A-5) and a baffle (A-6); The connection method of the components in the left front leg mechanism (A) is as follows: the rear variable stiffness joint part (A-1) and the rear leg group connecting rod part (A-2) are rotationally connected through an assembly axis; the rear variable stiffness joint part (A-1) and the baffle (A-6) are rotationally connected through an assembly axis; the rear leg group connecting rod part (A-2) and the power drive part (A-3) are rotationally connected through an assembly axis; the rear leg group connecting rod part (A-2) and the power drive part (A-3) are fixedly connected to the baffle (A-6) through bolts; the rod shape, mechanical structure and assembly method of the front leg group connecting rod part (A-4) and the rear leg group connecting rod part (A-2) are exactly the same, and are longitudinally symmetrical with respect to the left front leg mechanism (A); the rod shape, mechanical structure and assembly method of the front variable stiffness joint part (A-5) and the rear variable stiffness joint part (A-1) are exactly the same, and are longitudinally symmetrical with respect to the left front leg mechanism (A). The rear variable stiffness joint (A-1) is composed of a long push rod connector (A-1-1), a short push rod connector (A-1-2), a spring (A-1-3), a limiting rod 1 (A-1-4), a gear 1 (A-1-5), a gear 2 (A-1-6), a gear 3 (A-1-7), a short transmission rod (A-1-8), a long transmission rod (A-1-9), a limiting rod 2 (A-1-10), a connecting rod (A-1-11), a rear mounting shaft (A-1-12), and a front mounting shaft (A-1-13); The connection method of the components in the rear variable stiffness joint (A-1) is as follows: the push rod long connector (A-1-1) and the push rod short connector (A-1-2) are fixedly connected by bolts; the push rod long connector (A-1-1) and the push rod rotating connector (F-3) are fixedly connected by bolts; the bottom mounting hole of the push rod long connector (A-1-1) and the middle mounting hole of the connecting rod (A-1-11) are flexibly connected by a spring (A-1-3); the push rod short connector (A-1-2) and the limit rod 1 (A-1-4) are fixedly connected by bolts; the bottom mounting hole of the limit rod 1 (A-1-4), the gear 1 (A-1-5) and the rear mounting shaft (A-1-12) are connected by key fit; the bottom mounting hole of the limit rod 2 (A-1-10), the connecting rod ( The bottom mounting hole of the baffle (A-1-11), the rear mounting hole of the baffle (A-6) and the rear mounting shaft (A-1-12) are rotatably connected; gear 1 (A-1-5), gear 2 (A-1-6) and gear 3 (A-1-7) are meshed and connected; gear 3 (A-1-7) and the transmission short rod (A-1-8) are fixedly connected through the key of the front mounting shaft (A-1-13); the front mounting hole of the baffle (A-6) is rotatably connected to the front mounting shaft (A-1-13); the upper mounting hole of the transmission short rod (A-1-8) and the bottom mounting hole of the transmission long rod (A-1-9) are rotatably connected through bolts; the upper mounting hole of the transmission long rod (A-1-9) and the upper mounting hole of the limit rod 2 (A-1-10) are rotatably connected through bolts; The front variable stiffness joint (A-5) and the rear variable stiffness joint (A-1) have the same rod shape, mechanical structure and assembly method, and are longitudinally symmetrical with respect to the left front leg mechanism (A); The rear leg group connecting rod part (A-2) includes: two first thigh rods (A-2-1), the first third auxiliary rod (A-2-2), the first straight rod (A-2-3), the first calf rod (A-2-4), the second calf rod (A-2-5), the second straight rod (A-2-6), the plug bolt (A-2-7), the second third auxiliary rod (A-2-8), two second thigh rods (A-2-9), and the base (A-2-10); The connection method of the parts in the connecting rod part (A-2) of the rear leg group is as follows: the first and second thigh rods (A-2-1, A-2-9) are three-pair rods, and the mounting holes are arranged at the top, bottom and middle positions; the first third-pair rod and the second third-pair rod (A-2-2, A-2-8) are three-pair rods, and the mounting holes are arranged at the three top corner positions; the long end mounting holes of the two first thigh rods (A-2-1) are rotatably connected to the upper mounting holes of the connecting rod (A-1-11) through the assembly shaft; the middle mounting holes of the two first thigh rods (A-2-1) are connected to the first third-pair rod (A-1-11) through the assembly shaft. -2-2) long end mounting holes are rotatably connected via an assembly shaft; the end mounting holes of the two first straight rods (A-2-3) and the bottom mounting holes of the short ends of the first three auxiliary rods (A-2-2) are rotatably connected via an assembly shaft; the bottom mounting holes of the two first thigh rods (A-2-1) and the upper mounting holes of the first calf rod (A-2-4) are rotatably connected via an assembly shaft; the other end mounting holes of the two first straight rods (A-2-3) and the middle mounting holes of the first calf rod (A-2-4) are rotatably connected via an assembly shaft; the first three auxiliary rods (A- 2-2) The upper mounting hole of the short end is connected to the upper mounting hole of the short end of the second third auxiliary rod (A-2-8) by plugging bolts (A-2-7); the upper mounting holes of the two second thigh rods (A-2-9) are connected to the bottom mounting holes of the base (A-2-10) by assembly shafts; the middle mounting holes of the two second thigh rods (A-2-9) are connected to the long end mounting holes of the second third auxiliary rod (A-2-8) by assembly shafts; the end mounting holes of the two second straight rods (A-2-6) are connected to the short end mounting holes of the second third auxiliary rod (A-2-8) by assembly shafts. The bottom mounting holes at the ends are rotatably connected via an assembly shaft; the bottom mounting holes at the short ends of the two second thigh rods (A-2-9) are rotatably connected to the upper mounting holes of the second calf rod (A-2-5) via an assembly shaft; the mounting holes at the other ends of the two second straight rods (A-2-6) are rotatably connected to the middle mounting holes of the second calf rod (A-2-5) via an assembly shaft; the mounting holes are arranged at four right angles to the base (A-2-10) and the axis direction is vertical; the base (A-2-10) is fixedly connected to the left front bottom plate (E-1-1); The front leg group connecting rod part (A-4) and the rear leg group connecting rod part (A-2) have the same rod shape, mechanical structure and assembly method, and are longitudinally symmetrical with respect to the left front leg mechanism (A); The power drive unit (A-3) is composed of a brushless DC motor (A-3-1), a right crank (A-3-2), a right leg group connector (A-3-3), a left leg group connector (A-3-4), a left crank (A-3-5), and a reducer (A-3-6); The connection method of the components in the power drive unit (A-3) is as follows: four mounting holes are evenly arranged at the end surface of the left leg group connector (A-3-4); the DC brushless motor (A-3-1), the right leg group connector (A-3-3), the left leg group connector (A-3-4), and the reducer (A-3-6) are fixedly connected by bolts; the reducer (A-3-6) and the right crank (A-3-2) are rotationally connected through an assembly shaft; the reducer (A-3-6) It is rotationally connected to the left crank (A-3-5) through an assembly shaft; the left leg group connecting part (A-3-4) and the right leg group connecting part (A-3-3) are arranged symmetrically about the motor axis; the phase difference between the left crank (A-3-5) and the right crank (A-3-2) is 180°; the DC brushless motor (A-3-1) drives the left crank (A-3-5) and the right crank (A-3-2) to rotate a full circle, realizing the walking movement of the left front leg mechanism (A).

2. The variable stiffness joint multi-legged walking platform according to claim 1, characterized in that: The trunk (E) is composed of a left front trunk (E-1), a left rear trunk (E-2), a right rear trunk (E-3), a right front trunk (E-4), a trunk long connector (E-5), a trunk short connector (E-6), a left push rod bend connector (E-7), a right push rod bend connector (E-8), and a trunk connector (E-9); The connection method of the parts in the torso (E) is as follows: the left front torso (E-1) and the right front torso (E-4) are fixedly connected to the two ends of the torso long connector (E-5) respectively; the left front torso (E-1) and the left rear torso (E-2) are fixedly connected to the two ends of the torso short connector (E-6) respectively; the torso connector (E-9) is fixedly connected to the left front torso (E-1), the left rear torso (E-2), the right rear torso (E-3), and the right front torso (E-4) respectively by bolts; the left push rod bent connector (E-7) and the right push rod bent connector (E-8) are fixedly connected to the torso connector (E-9) respectively by bolts; The left front trunk (E-1) is composed of a left front first long connector (E-1-1), a left front first transverse connector (E-1-2), a left front first short connector (E-1-3), a left front second long connector (E-1-4), a left front second transverse connector (E-1-2), a left front second transverse connector (E-1-5), a left front first short connector (E-1-6), and an adjustment gasket (E-1-7); The connection method of the components in the left front trunk (E-1) is as follows: in the left front trunk (E-1), the left front first long connector (E-1-1) and the left front second long connector (E-1-4) are fixedly connected to the two ends of the left front first short connector and the left front second short connector (E-1-3 and E-1-6) respectively; the adjustment gasket (E-1-7) is fixedly connected to the left front first long connector (E-1-1); the two ends of the left front first transverse connector (E-1-2) and the left front second transverse connector (E-1-5) are fixedly connected to the upper end of the adjustment gasket (E-1-7) and the left front first long connector (E-1-4) respectively; the left front first long connector (E-1-1) is fixedly connected to the lower surface of the adjustment gasket (E-1-7); The rod shapes, mechanical structures and assembly methods of the left front torso (E-1), left rear torso (E-2), right rear torso (E-3) and right front torso (E-4) in the torso (E) are exactly the same; the left front torso, right front torso (E-1, E-4) and the left rear torso, right rear torso (E-2, E-3) are mirror-arranged with respect to the transverse symmetry plane of the variable stiffness joint multi-legged walking platform; the left front torso, left rear torso (E-1, E-2) and the right front torso, right rear torso (E-4, E-3) are mirror-arranged with respect to the longitudinal symmetry plane of the variable stiffness joint multi-legged walking platform.

3. The variable stiffness joint multi-legged platform according to claim 1, characterized in that: The left push rod mechanism (F) is composed of a push rod (F-1), a push rod connecting member (F-2), and a push rod rotating connecting member (F-3); The connection method of the components in the left push rod mechanism (F) is as follows: the push rod (F-1) and the push rod connector (F-2) are rotationally connected through an assembly shaft; the push rod connector (F-2) and the push rod rotation connector (F-3) are fixedly connected by bolts.

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