A rope-driven mechanical leg based on a rolling contact joint

Abstract

A kind of rope-driven mechanical leg based on rolling contact joint belongs to the field of robot technology.All drivers are mounted on hip joint mounting plate, hip joint is fixed below hip joint mounting plate, hip joint is connected with knee joint through upper connecting rod, knee joint is connected with ankle joint through two lower connecting rods, knee joint, ankle joint and two lower connecting rods form parallelogram linkage structure;All joints use rolling contact joint, rolling contact joint is composed of two contact and rolling connecting rolling bodies, one end of hip joint active rope is connected with corresponding driver, and the other end is connected with the rolling body of hip joint;Knee joint and ankle joint are each provided with two rolling contact joints, two rolling bodies of each rolling contact joint are connected using two constraint ropes;One end of knee joint and ankle joint active rope is connected with corresponding driver, and the other end is connected with lower connecting rod by passing through the rolling contact joint of knee joint.The present application can optimize stress condition, reduce wear and tear, and improve the service life of robot.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of robot technology, and particularly relates to a rope-driven mechanical leg based on a rolling contact joint applied to a bionic foot-type robot, and particularly relates to a transmission structure optimized in stress condition through a rolling contact joint. BACKGROUND

[0002] At present, common robot moving modes include wheel type, track type and foot type. Compared with other types of mobile robots, foot-type robots can use isolated ground support instead of continuous ground support required by wheel-type robots, which makes them have stronger mobility and adaptability on uneven ground. Foot-type robots have the characteristics of multiple limbs and multiple degrees of freedom, and provide good selectivity and flexibility, and are particularly suitable for working in environments with uncertain factors.

[0003] With the continuous development of foot-type robots, the types of their most important mechanical leg structures have gradually increased. The mechanical leg of a traditional foot-type robot generally uses a motor in combination with a reducer to achieve driving. This structure needs to arrange the motor and related reducer at the joint of the foot-type robot. Although this traditional mechanical leg structure of the foot-type robot is simple, it results in a large leg mass, and the motor and reducer of the next level joint become an additional load of the previous level joint, which leads to certain negative results. Most traditional foot-type robots use traditional pin shaft type rotary pair joints. The stress condition of this traditional structure joint is poor and its wear condition is also serious, so that the service life of the traditional foot-type robot is short.

[0004] Most existing foot-type robot mechanical legs use active motor driving, and the linkage of movement is realized through a control algorithm, which has poor coordination and reduces the working efficiency of the foot-type robot to a certain extent, resulting in low energy utilization rate. The invention patent application with the application publication number CN106985927A and the publication date of December 30, 2016 discloses a steel wire rope transmission four-legged or multi-legged robot. Although this robot uses a rope drive to arrange the driver inside the body, it avoids the problem of large leg mass to a certain extent, but its mechanical leg joint uses a traditional rigid pin shaft type rotary pair joint. The stress condition of this joint is not ideal, the wear is serious, and the working life is short. SUMMARY

[0005] The purpose of the present application is to solve the problems of large structure mass and short service life of the traditional foot-type robot mechanical leg, and to provide a rope-driven mechanical leg based on a rolling contact joint.

[0006] The application is based on the animal joint and designs a rope-driven mechanical leg of a rope-driven legged robot based on a rolling contact joint.

[0007] The application simulates the leg muscle and bone structure of an animal, and utilizes a rope drive, added springs and a unique parallelogram-like linkage structure to better understand the biological structure principle of the animal movement ability, and to facilitate the promotion in bionics and the like.

[0008] To achieve the above object, the technical scheme adopted by the application is:

[0009] A rope-driven mechanical leg based on a rolling contact joint, comprising a hip joint mounting plate, a hip joint, a knee joint, an ankle joint, an upper linkage, two lower linkages and three drivers; the three drivers are all fixedly mounted on the hip joint mounting plate, and the three drivers are a first driver, a second driver and a third driver respectively;

[0010] The hip joint is fixed below the hip joint mounting plate, all the joints adopt rolling contact joints, the rolling contact joint is composed of two rolling bodies in contact and rolling connection, two hip joint driving ropes are connected with the first driver and the third driver at one end, and connected with the rolling bodies on the left and right sides of the hip joint at the other end;

[0011] The knee joint and the ankle joint are each provided with two rolling contact joints, the two rolling bodies of each rolling contact joint are integrally connected by two constraint ropes; the rolling contact joint of the hip joint is connected with the rolling contact joint of the knee joint through the upper linkage, the rolling contact joint of the knee joint is connected with the rolling contact joint of the ankle joint through the two lower linkages arranged in front and back, the knee joint and the ankle joint form a parallelogram-like linkage structure with the two lower linkages; the knee joint and the ankle joint driving rope is connected with the second driver at one end, and connected with the lower linkage located in front and bypassing the rolling contact joint of the knee joint at the other end.

[0012] Further, the two rolling bodies of the rolling contact joint of the hip joint are a hip joint upper part gear-like rolling body and a hip joint lower part gear-like rolling body; the lower end arc surface of the hip joint upper part gear-like rolling body and the upper end arc surface of the hip joint lower part gear-like rolling body are both provided with a plurality of teeth, and the hip joint upper part gear-like rolling body and the hip joint lower part gear-like rolling body are in meshing engagement with each other;

[0013] Two said hip joint active ropes are respectively hip joint front side active rope and hip joint back side active rope, one end of hip joint front side active rope and hip joint back side active rope is connected with driver one and driver three respectively, the other end of hip joint front side active rope and hip joint back side active rope respectively passes through pulley one rotatingly installed on the front and back sides of hip joint upper part gear rolling body and the front and back sides of hip joint lower part gear rolling body.

[0014] Further, two said rolling contact joints of knee joint are respectively knee joint upper part rolling contact joint and knee joint lower part rolling contact joint, two said rolling bodies of knee joint upper part rolling contact joint and knee joint lower part rolling contact joint are respectively knee joint upper part rolling body and knee joint lower part rolling body; two knee joint upper part rolling bodies of two rolling contact joints of knee joint are connected through knee joint connecting rod;

[0015] Two said constraint ropes connected with two said rolling bodies of each rolling contact joint of knee joint are respectively knee joint rolling body constraint rope one and knee joint rolling body constraint rope two, after knee joint rolling body constraint rope one and knee joint rolling body constraint rope two are connected with knee joint upper part rolling body and knee joint lower part rolling body of rolling contact joint, knee joint rolling body constraint rope one and knee joint rolling body constraint rope two form 'X' shape intersection structure.

[0016] Further, the front and back sides of knee joint upper part rolling body and knee joint lower part rolling body of each rolling contact joint of knee joint are connected through knee joint elastic element.

[0017] Further, two said rolling contact joints of ankle joint are respectively ankle joint upper part rolling contact joint and ankle joint lower part rolling contact joint, two said rolling bodies of ankle joint upper part rolling contact joint and ankle joint lower part rolling contact joint are respectively ankle joint upper part rolling body and ankle joint lower part rolling body; two ankle joint lower part rolling bodies of two rolling contact joints of ankle joint are connected through ankle joint connecting rod;

[0018] Two said constraint ropes connected with two said rolling bodies of each rolling contact joint of ankle joint are respectively ankle joint rolling body constraint rope one and ankle joint rolling body constraint rope two, after ankle joint rolling body constraint rope one and ankle joint rolling body constraint rope two are connected with ankle joint upper part rolling body and ankle joint lower part rolling body of rolling contact joint, ankle joint rolling body constraint rope one and ankle joint rolling body constraint rope two form 'X' shape intersection structure;

[0019] The upper ankle rolling body of the ankle joint is connected with the lower knee rolling body of the knee joint through the lower connecting rod located at the front side, and the upper knee rolling body of the knee joint is connected with the lower ankle rolling body of the ankle joint through the lower connecting rod located at the rear side.

[0020] Further, the upper and lower ankle rolling bodies of each rolling contact joint of the ankle joint are connected through the elastic element of the ankle joint.

[0021] Further, the lower knee rolling body of the upper knee rolling contact joint is rotatably installed with a pulley two, and the other end of the knee and ankle driving rope is wound around the pulley one located at the rear side of the upper hip gear rolling body and the pulley two and connected with the lower connecting rod located at the front side.

[0022] Further, the rope-driven mechanical leg further comprises a knee spring combination body, which comprises a knee spring installation moving pair structure, a knee spring and a knee spring moving pair connecting clamping plate; the knee spring installation moving pair structure comprises a connecting column one and an end one fixed at both ends of the connecting column one, the knee spring and the knee spring moving pair connecting clamping plate are sleeved on the connecting column one from top to bottom and located between the two end ones, and the knee spring moving pair connecting clamping plate is connected with the knee connecting rod.

[0023] The front side of the upper knee rolling body of the lower knee rolling contact joint is rotatably installed with a pulley three, one end of the knee spring passive connecting rope is connected with the end one located at the lower end of the connecting column one, and the other end of the knee spring passive connecting rope is wound around the pulley three and connected with the lower knee rolling body of the lower knee rolling contact joint.

[0024] Further, the rope-driven mechanical leg further comprises a double-joint spring combination body, which comprises a double-joint spring installation moving pair structure and a double-joint spring; the double-joint spring installation moving pair structure comprises a connecting column two and two end twos, the lower connecting rod located at the rear side is divided into an upper segment and a lower segment, cavities are arranged in the middle portions of the upper segment and the lower segment, coaxial through holes are arranged in the middle portions of the two opposite ends of the upper segment and the lower segment, the connecting column two penetrates through the through holes of the upper segment and the lower segment, the end twos are fixed at both ends of the connecting column two, the double-joint spring is sleeved on the connecting column two, and the double-joint spring is arranged in the cavity of the lower segment.

[0025] Further, the lower end of the lower ankle rolling body of the ankle joint is connected with the mechanical leg foot bottom.

[0026] The beneficial effects of the present application relative to the prior art are:

[0027] 1. Compared to traditional legged robotic legs, the present invention utilizes a cable-driven transmission to position the larger actuator away from the end effector. This rational arrangement reduces the leg's inertia and improves dynamic performance. Furthermore, the cable-driven transmission offers the advantages of flexible arrangement and minimal geometric space occupation, making it highly suitable for use in robotic legs.

[0028] 2. The rolling contact joint used in the present invention is composed of two adjacent rolling bodies connected by a constraint rope by imitating the structure of the human skeletal joint. Compared with the traditional pin-type revolute joint, this structure has the advantages of optimizing the stress conditions and reducing wear, thereby improving the service life of the robot to a certain extent.

[0029] 3. The knee joint spring installed in the present invention simulates the quadriceps and patellar tendon structure of a biological leg to maintain the stability of the knee joint and provide a certain amount of support during static and dynamic movements. The spring installation structure can absorb impact energy during landing and release energy to assist propulsion during the take-off phase; the double-joint spring can store energy and coordinate the effect of the knee joint spring, and reduce dependence on hip joint movement during movement; by designing the knee joint spring and the double-joint spring based on the muscle structure of the biological leg, the synergistic effect of the two can reduce energy consumption and improve the robustness of dynamic movement. The passive elastic mechanism is used to simplify the control complexity and reduce the intervention of the active actuator, making the mechanical leg closer to the functional morphology of the animal leg.

[0030] 4. The mechanical leg of the present invention realizes the coupling of joint motion through a parallelogram-like connecting rod structure, thereby reducing the degree of freedom required for motion.

[0031] 5. Compared with the traditional pin-type revolute joint, the rolling contact joint of the present invention optimizes its force conditions, reduces the wear of the joint, and to a certain extent helps to improve the life of the mechanical leg. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 1 is an overall isometric diagram of a rope-driven mechanical leg based on a rolling contact joint according to the present invention, with the three actuators not shown;

[0033] Figure 2 This is a schematic front view of the entire rope-driven mechanical leg based on the rolling contact joint of the present invention.

[0034] Figure 3 It is a schematic diagram of a structure in which two rolling elements of a knee joint or two rolling elements of an ankle joint are respectively connected to two restraining ropes;

[0035] Figure 4 It is a schematic diagram of the structure of the connection between the knee joint spring assembly and the knee joint;

[0036] Figure 5is a structure diagram of the double-joint spring combination connecting with the upper segment lower connecting rod and the lower segment lower connecting rod located at the rear side.

[0037] The component names and reference numerals involved in the above-mentioned drawings are as follows:

[0038] 1, mechanical leg mounting plate; 2, hip joint mounting plate; 3, hip joint; 301, hip joint upper part similar gear rolling body; 302, hip joint lower part similar gear rolling body; 4, knee joint; 401, knee joint upper part rolling contact joint; 402, knee joint lower part rolling contact joint; 403, knee joint upper part rolling body; 404, knee joint lower part rolling body; 405, knee joint connecting rod; 5, ankle joint; 501, ankle joint upper part rolling contact joint; 502, ankle joint lower part rolling contact joint; 503, ankle joint upper part rolling body; 504, ankle joint lower part rolling body; 505, ankle joint connecting rod; 6, upper connecting rod; 7, lower connecting rod; 701, upper segment lower connecting rod; 702, double-joint spring mounting clamp plate; 703, lower segment lower connecting rod; 8, driver one; 9, driver two; 10, hip joint rear side active rope; 11, knee joint rolling body constraint rope one; 12, knee joint and ankle joint active rope; 13, pulley one; 14, knee joint rolling body constraint rope two; 15, hip joint front side active rope; 16, ankle joint rolling body constraint rope one; 17, ankle joint rolling body constraint rope two; 18, pulley two; 19, knee joint spring combination; 1901, knee joint spring; 1902, connecting column one; 1903, end one; 1904, knee joint spring moving pair connecting clamp plate; 20, pulley three; 21, knee joint spring passive connecting rope; 22, double-joint spring combination; 2201, double-joint spring; 2202, connecting column two; 2203, end two; 23, mechanical leg foot bottom; 24, driver three. DETAILED DESCRIPTION

[0039] DETAILED DESCRIPTION Figures 1-5 As shown in the figure, the embodiment discloses a rolling contact joint-based rope-driven mechanical leg, which comprises a mechanical leg mounting plate 1, a hip joint mounting plate 2, a hip joint 3, a knee joint 4, an ankle joint 5, an upper connecting rod 6, a mechanical leg foot bottom 11, two lower connecting rods 7, and three drivers (electromagnetic motors are selected); the three drivers are fixedly installed on the hip joint mounting plate 2, and the three drivers are a driver one 8, a driver two 9, and a driver three 24 respectively.

[0040] The hip joint mounting plate 2 is fixedly connected with the mechanical leg mounting plate 1 on one side, the hip joint 3 is fixed below the hip joint mounting plate 2 (through a screw), all the joints are rolling contact joints, the rolling contact joint is composed of two rolling bodies connected through contact and rolling, two hip joint active ropes are connected with the driver one 8 and the driver three 24 at one end respectively, and the two hip joint active ropes are connected with the rolling bodies on the left and right sides of the hip joint at the other end.

[0041] The knee joint 4 and the ankle joint 5 are each provided with two rolling contact joints, and the two rolling bodies of each rolling contact joint are integrally connected by two constraint ropes; the rolling contact joints of the hip joint 3 are connected with the rolling contact joints of the knee joint 4 through the upper connecting rod 6, the rolling contact joints of the knee joint 4 are connected with the rolling contact joints of the ankle joint 5 through the two lower connecting rods 7 arranged in front and back, the knee joint 4 and the ankle joint 5 and the two lower connecting rods 7 form a parallelogram-like connecting rod structure, the lower end of the ankle joint 5 is connected with the mechanical leg sole 11; one end of the knee joint and ankle joint active rope 12 is connected with the driver two 9, and the other end of the knee joint and ankle joint active rope 12 passes through the rolling contact joint of the knee joint 4 and is connected with the lower connecting rod 7 located on the front side.

[0042] Further, the two rolling bodies of the rolling contact joint of the hip joint 3 are respectively a hip joint upper part gear-like rolling body 301 and a hip joint lower part gear-like rolling body 302; the lower end arc surface of the hip joint upper part gear-like rolling body 301 and the upper end arc surface of the hip joint lower part gear-like rolling body 302 are each provided with a plurality of teeth, and the hip joint upper part gear-like rolling body 301 and the hip joint lower part gear-like rolling body 302 are meshed with each other.

[0043] The two hip joint active ropes are respectively a hip joint front side active rope 15 and a hip joint rear side active rope 10, one end of the hip joint front side active rope 15 and the hip joint rear side active rope 10 is respectively connected with the driver one 8 and the driver three 24, and the other end of the hip joint front side active rope 15 and the hip joint rear side active rope 10 is respectively connected with the front and rear sides of the hip joint lower part gear-like rolling body 302 through the pulley one 13 rotatably installed on the front and rear sides of the hip joint upper part gear-like rolling body 301 (the front and rear sides of the hip joint lower part gear-like rolling body 302 are each provided with a rope connecting hole one, and the other end of the hip joint front side active rope 15 and the hip joint rear side active rope 10 is connected with the rope connecting hole one on the front and rear sides of the hip joint lower part gear-like rolling body 302).

[0044] Since the hip joint 3 is large in volume and is prone to generate large sliding, the hip joint 3 is designed as a gear-like structure to realize a gear-like transmission structure. The hip joint rear side active rope 10 and the hip joint front side active rope 15 are respectively used to drive the hip joint 3 to rotate counterclockwise or clockwise.

[0045] The hip joint rear side active rope 10 and the hip joint front side active rope 15 apply external force to the rolling bodies of the hip joint to realize the rotation of the kinematic pair, and the two oppositely arranged active ropes can also realize the change of rigidity in the subsequent control process.

[0046] Further, the two rolling contact joints of the knee joint 4 are respectively the upper knee joint rolling contact joint 401 and the lower knee joint rolling contact joint 402, and the two rolling bodies of the upper knee joint rolling contact joint 401 and the lower knee joint rolling contact joint 402 are respectively the upper knee joint rolling body 403 and the lower knee joint rolling body 404 (the lower end surface of the upper knee joint rolling body 403 and the upper end surface of the lower knee joint rolling body 404 are both arc-shaped contact surfaces, and the upper knee joint rolling body 403 and the lower knee joint rolling body 404 are in rolling connection through the arc-shaped contact surfaces).

[0047] The two constraint ropes connected with the two rolling bodies of each rolling contact joint of the knee joint 4 are respectively the knee joint rolling body constraint rope one 11 and the knee joint rolling body constraint rope two 14, and after being connected with the upper knee joint rolling body 403 and the lower knee joint rolling body 404 of the rolling contact joint, the knee joint rolling body constraint rope one 11 and the knee joint rolling body constraint rope two 14 form an 'X' intersecting structure.

[0048] This structure imitates the animal knee joint and other movement joints, imitates the joint bones by using the rolling bodies, and imitates the cruciate ligament by using the constraint ropes. The existence of the constraint ropes can prevent the rolling contact joint from moving excessively forward or backward, and can also restrict the up-and-down movement of the joint to a certain extent.

[0049] Further, the front and rear side surfaces of the upper knee joint rolling body 403 and the lower knee joint rolling body 404 of each rolling contact joint of the knee joint 4 are connected through the knee joint elastic element (screws are fixed on the front and rear side surfaces of the upper knee joint rolling body 403 and the lower knee joint rolling body 404, the knee joint elastic element is fixed through the screws, and the two rolling bodies of the rolling contact joint of the knee joint 4 are connected through the knee joint elastic element).

[0050] The front and rear side surfaces of the upper knee joint rolling body 403 and the lower knee joint rolling body 404 are connected through the knee joint elastic element to realize the constraint on the radial sliding, and to a certain extent, provide a restoring torque, so that the knee joint 4 can return to the initial position after movement (the knee joint elastic element can provide a restoring torque for restoring the initial position of the rolling body). The knee joint elastic element is a spring, such as a compression spring.

[0051] Further, the two rolling contact joints of the ankle joint 5 are respectively an upper ankle joint rolling contact joint 501 and a lower ankle joint rolling contact joint 502, and the two rolling bodies of the upper ankle joint rolling contact joint 501 and the lower ankle joint rolling contact joint 502 are respectively an upper ankle joint rolling body 503 and a lower ankle joint rolling body 504 (the lower end surface of the upper ankle joint rolling body 503 and the upper end surface of the lower ankle joint rolling body 504 are both arc-shaped contact surfaces, and the upper ankle joint rolling body 503 and the lower ankle joint rolling body 504 are connected by the arc-shaped contact surfaces to realize rolling connection); the two lower ankle joint rolling bodies 504 of the two rolling contact joints of the ankle joint 5 are connected by an ankle joint connecting rod 505.

[0052] The two constraint ropes connected with the two rolling bodies of each rolling contact joint of the ankle joint 5 are respectively an ankle joint rolling body constraint rope one 16 and an ankle joint rolling body constraint rope two 17, and after the ankle joint rolling body constraint rope one 16 and the ankle joint rolling body constraint rope two 17 are connected with the upper ankle joint rolling body 503 and the lower ankle joint rolling body 504 of the rolling contact joint, the ankle joint rolling body constraint rope one 16 and the ankle joint rolling body constraint rope two 17 form an 'X' intersecting structure.

[0053] The upper ankle joint rolling body 503 of the lower ankle joint rolling contact joint 502 is connected with the lower knee joint rolling body 404 of the lower knee joint rolling contact joint 402 through the lower connecting rod 7 located at the front side, and the upper ankle joint rolling body 503 of the upper ankle joint rolling contact joint 501 is connected with the lower knee joint rolling body 404 of the upper knee joint rolling contact joint 401 through the lower connecting rod 7 located at the rear side; the lower end of the lower ankle joint rolling body 504 of the lower ankle joint rolling contact joint 502 is connected with the mechanical leg sole 11.

[0054] The technical effects of the present technical solution are the same as those of the knee joint 4.

[0055] Further, the front and rear sides of the upper ankle joint rolling body 503 and the lower ankle joint rolling body 504 of each rolling contact joint of the ankle joint 5 are connected by ankle joint elastic elements (screws are fixed on the front and rear sides of the upper ankle joint rolling body 503 and the lower ankle joint rolling body 504, the ankle joint elastic elements are fixed by the screws, and the two rolling bodies of the rolling contact joint of the ankle joint 5 are connected by the ankle joint elastic elements). The technical effects of the present technical solution are the same as those of the knee joint 4.

[0056] The ankle joint elastic element is a spring such as a compression spring.

[0057] Further, the pulley two 18 is rotatably installed in the knee lower rolling contact joint 404 of the knee upper rolling contact joint 401, and the other end of the knee and ankle active rope 12 is connected with the pulley one 13 on the rear side of the knee upper rolling contact joint 401 and the pulley two 18 and the lower connecting rod 7 on the front side (the lower connecting rod 7 on the front side is provided with a connecting rope hole two, and the other end of the knee and ankle active rope 12 is connected with the connecting rope hole two).

[0058] The knee and ankle active rope 12 mainly drives the knee joint 4 and the ankle joint 5, and since the knee joint 4 and the ankle joint 5 form a parallel quadrilateral connecting rod structure with the two lower connecting rods 7, the motion of the knee joint 4 and the ankle joint 5 is coupled, and a single driving rope (the knee and ankle active rope 12) can realize the combined motion of the two joints. Since the foot-type robot has only two states of lifting legs and being in place during the motion, the active rope arranged on one side can meet the motion needs.

[0059] Further, the rope-driven mechanical leg further comprises a knee spring assembly 19, and the knee spring assembly 19 comprises a knee spring installation moving pair structure, a knee spring 1901, and a knee spring moving pair connecting clamping plate 1904; the knee spring installation moving pair structure comprises a connecting column one 1902 and end heads one 1903 fixed at both ends of the connecting column one 1902, the knee spring 1901 and the knee spring moving pair connecting clamping plate 1904 are sleeved on the connecting column one 1902 from top to bottom and located between the two end heads one 1903 (the two ends of the knee spring 1901 are connected with the knee spring moving pair connecting clamping plate 1904 and the end heads one 1903), and the knee spring moving pair connecting clamping plate 1904 is connected with the knee connecting rod 405 (the front side of the knee connecting rod 405 is provided with a connecting convex column, and the connecting convex column is fixedly installed in the clamping port of the knee spring moving pair connecting clamping plate 1904).

[0060] The pulley three 20 is rotatably installed on the front side of the knee upper rolling body 403 of the knee lower rolling contact joint 402, one end of the knee spring passive connecting rope 21 is connected with the end head one 1903 at the lower end of the connecting column one 1902, and the other end of the knee spring passive connecting rope 21 is connected with the knee lower rolling contact joint 402 of the knee lower rolling body 404 after passing through the pulley three 20 (the knee lower rolling contact joint 402 of the knee lower rolling body 404 is provided with a connecting hole three, and the other end of the knee spring passive connecting rope 21 is connected with the connecting rope hole three of the knee lower rolling contact joint 402 of the knee lower rolling body 404).

[0061] The knee joint 4 is provided with a knee joint spring 1901, which is installed between the moving pair structure and the knee joint spring moving pair connecting plate 1904 connected with the knee joint connecting rod 405 to form a moving pair structure. The spring moves in the form of a moving pair to constrain the movement of the knee joint 4. The knee joint spring assembly 19 designed by simulating the quadriceps femoris and patellar tendon structure of the biological leg provides elasticity in the virtual mechanical leg shaft direction, which can maintain the stability and support force of the knee joint 4 in static and dynamic movement. The structure can also absorb impact energy during the landing stage of the bounce and release energy during the take-off stage to assist propulsion.

[0062] Further, the rope-driven mechanical leg further comprises a double-joint spring assembly 22, which comprises a double-joint spring installation moving pair structure and a double-joint spring 2201; the double-joint spring installation moving pair structure comprises a connecting column two 2202 and two end heads two 2203. The lower connecting rod 7 on the rear side is divided into upper and lower two sections. The middle part of the upper section lower connecting rod and the lower section lower connecting rod 703 is provided with a cavity. The middle part of the two opposite ends of the upper section lower connecting rod and the lower section lower connecting rod 703 is provided with a coaxial through hole. The connecting column two 2202 passes through the through hole of the upper section lower connecting rod and the lower section lower connecting rod 703. The two ends of the connecting column two 2202 are fixed with the end head two 2203. The double-joint spring 2201 is sleeved on the connecting column two 2202, and the double-joint spring 2201 is arranged in the cavity of the lower section lower connecting rod 703.

[0063] The double-joint spring 2201 is arranged at the knee joint 4 and the ankle joint 5, which simulates the gastrocnemius-tendon complex of the biological leg, provides elasticity in the angle direction of the mechanical leg, and can adjust the joint posture through an additional degree of freedom under the action of the hip joint torque, store energy in the double-joint spring 2201, and reduce the dependence on the hip actuator (external device). The double-joint spring 2201 can also cooperate with the knee joint spring 1901 to realize multi-directional energy storage and release, and improve the overall energy efficiency.

[0064] The design of the knee joint spring 1901 and the double-joint spring 2201 makes the mechanical leg closer to the functional form of the animal leg, simplifies the control complexity through the passive elastic mechanism to reduce the intervention of the active actuator (external device), and can improve the robustness of dynamic movement to a certain extent.

[0065] The upper section lower connecting rod comprises an upper section lower connecting rod 701 and a double-joint spring installation clamping plate 702. The lower end of the upper section lower connecting rod 701 is provided with an opening. The lower end of the upper section lower connecting rod 701 is arranged in the clamping opening of the double-joint spring installation clamping plate 702, and the two are connected by screws. The pulley two 18 is rotatably installed in the middle part of the top surface of the upper section lower connecting rod 701.

[0066] The pulley one 13 is arranged on the upper part of the knee joint 4, and the rope hole is arranged on the lower part, so that the rope arrangement is installed, and the rotation of the knee joint 4 is realized by the extension and retraction of the two end ropes; the rope hole is arranged on the common connecting rod (the lower connecting rod 7) of the knee joint and the ankle joint, and the pulley two 18 is arranged in the upper part of the split connecting rod (the upper lower connecting rod 701) of the double joint spring 2201, which is driven by the knee joint and ankle joint driving rope 12 to realize the lifting movement of the mechanical leg, and the putting down movement is realized by the knee joint and ankle joint driving rope 12 being retracted and the passive spring (the knee joint spring 1901).

[0067] The hip joint rear driving rope 10 and the hip joint front driving rope 15 are respectively used to drive the hip joint 3 to rotate counterclockwise and clockwise.

[0068] The knee joint spring 1402 and the double joint spring 802 are designed to make the mechanical leg closer to the functional form of the animal leg, simplify the control complexity through the passive elastic mechanism to reduce the intervention of the active actuator, and improve the robustness of dynamic motion to a certain extent.

[0069] The working process is: the hip joint front driving rope 15 is stretched through the driver one 8, the hip joint rear driving rope 10 is retracted through the driver three 24, and the knee joint and ankle joint driving rope 12 is retracted through the driver two 9, so that the leg folding and backward swinging process of the mechanical leg is realized; the hip joint front driving rope 15 is retracted through the driver one 8, the hip joint rear driving rope 10 is stretched through the driver three 24, and the knee joint and ankle joint driving rope 12 is stretched through the driver two 9, and the knee joint spring 1901 is matched to realize the leg putting down and forward swinging process of the mechanical leg.

[0070] It is obvious for those skilled in the art that the present application is not limited to the details of the above-mentioned exemplary embodiments, and can be implemented in other forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and all changes falling within the meaning and scope of the equivalent conditions of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0071] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can be combined to form other embodiments which can be understood by those skilled in the art.

Claims

1. A rope-driven robotic leg based on a rolling contact joint, characterized by: It includes a hip joint mounting plate (2), a hip joint (3), a knee joint (4), an ankle joint (5), an upper connecting rod (6), two lower connecting rods (7), three drivers and a knee joint spring assembly (19); the three drivers are all fixedly mounted on the hip joint mounting plate (2), and the three drivers are driver one (8), driver two (9) and driver three (24); The hip joint (3) is fixed below the hip joint mounting plate (2), and all the joints are rolling contact joints, which are composed of two rolling bodies that are in contact and rolling connection. One end of the two hip joint active ropes is connected to the driver 1 (8) and the driver 3 (24) respectively, and the other end of the two hip joint active ropes is connected to the left and right sides of the rolling bodies of the hip joint; The knee joint (4) and the ankle joint (5) are each provided with two rolling contact joints, and the two rolling bodies of each rolling contact joint are integrally connected by two restraining ropes; the rolling contact joint of the hip joint (3) and the rolling contact joint of the knee joint (4) are connected via an upper connecting rod (6), and the rolling contact joint of the knee joint (4) and the rolling contact joint of the ankle joint (5) are connected via two lower connecting rods (7) arranged front and back, and the knee joint (4) and the ankle joint (5) form a parallelogram connecting rod structure with the two lower connecting rods (7); one end of the active rope (12) of the knee joint and the ankle joint is connected to the second driver (9), and the other end of the active rope (12) of the knee joint and the ankle joint passes around the rolling contact joint of the knee joint (4) and is connected to the lower connecting rod (7) located at the front side; The two rolling contact joints of the knee joint (4) are respectively an upper knee joint rolling contact joint (401) and a lower knee joint rolling contact joint (402); the two rolling bodies of the upper knee joint rolling contact joint (401) and the lower knee joint rolling contact joint (402) are respectively an upper knee joint rolling body (403) and a lower knee joint rolling body (404); the two upper knee joint rolling bodies (403) of the two rolling contact joints of the knee joint (4) are connected via a knee joint connecting rod (405); the upper knee joint rolling body (403) of the upper knee joint rolling contact joint (401) and the gear-like rolling body (302) of the lower hip joint are connected via the upper connecting rod (6); The two restraint ropes connected to the two rolling bodies of each rolling contact joint of the knee joint (4) are respectively a knee joint rolling body restraint rope 1 (11) and a knee joint rolling body restraint rope 2 (14). After the knee joint rolling body restraint rope 1 (11) and the knee joint rolling body restraint rope 2 (14) are connected to the upper knee joint rolling body (403) and the lower knee joint rolling body (404) of the rolling contact joint, the knee joint rolling body restraint rope 1 (11) and the knee joint rolling body restraint rope 2 (14) form an 'X'-shaped intersection structure; The knee joint spring assembly (19) comprises a knee joint spring mounting movable pair structure, a knee joint spring (1901) and a knee joint spring movable pair connecting splint (1904); the knee joint spring mounting movable pair structure comprises a connecting column (1902) and end heads (1903) fixed at both ends of the connecting column (1902); the knee joint spring (1901) and the knee joint spring movable pair connecting splint (1904) are mounted on the connecting column (1902) from top to bottom and are located between the two end heads (1903); the knee joint spring movable pair connecting splint (1904) is connected to the knee joint connecting rod (405); The front side of the upper knee joint rolling body (403) of the lower knee joint rolling contact joint (402) is rotatably mounted with a pulley three (20), one end of the knee joint spring passive connecting rope (21) is connected to the end one (1903) at the lower end of the connecting column one (1902), and the other end of the knee joint spring passive connecting rope (21) passes around the pulley three (20) and is connected to the lower knee joint rolling body (404) of the lower knee joint rolling contact joint (402).

2. The rope-driven robotic leg based on rolling contact joint according to claim 1, characterized in that: The two rolling bodies of the rolling contact joint of the hip joint (3) are respectively the upper gear-like rolling body (301) of the hip joint and the lower gear-like rolling body (302) of the hip joint; the lower arc surface of the upper gear-like rolling body (301) of the hip joint and the upper arc surface of the lower gear-like rolling body (302) of the hip joint are both provided with a plurality of teeth, and the upper gear-like rolling body (301) of the hip joint and the lower gear-like rolling body (302) of the hip joint are meshed with each other; The two hip joint active ropes are respectively the front hip joint active rope (15) and the rear hip joint active rope (10), one end of the front hip joint active rope (15) and the rear hip joint active rope (10) are respectively connected to the driver one (8) and the driver three (24), and the other end of the front hip joint active rope (15) and the rear hip joint active rope (10) are respectively passed around the pulley one (13) rotatably mounted on the front and rear sides of the gear-like rolling body (301) of the upper part of the hip joint and connected to the front and rear sides of the gear-like rolling body (302) of the lower part of the hip joint.

3. The rope-driven robotic leg based on rolling contact joint according to claim 1, characterized in that: The front and rear side surfaces of the upper knee joint rolling body (403) and the lower knee joint rolling body (404) of each rolling contact joint of the knee joint (4) are respectively connected via a knee joint elastic element.

4. The rope-driven robotic leg based on rolling contact joints according to claim 1, characterized in that: The two rolling contact joints of the ankle joint (5) are respectively an upper ankle rolling contact joint (501) and a lower ankle rolling contact joint (502); the two rolling bodies of the upper ankle rolling contact joint (501) and the lower ankle rolling contact joint (502) are respectively an upper ankle rolling body (503) and a lower ankle rolling body (504); the two lower ankle rolling bodies (504) of the two rolling contact joints of the ankle joint (5) are connected via an ankle joint connecting rod (505); The two restraint ropes connected to the two rolling bodies of each rolling contact joint of the ankle joint (5) are ankle joint rolling body restraint rope 1 (16) and ankle joint rolling body restraint rope 2 (17), respectively. After the ankle joint rolling body restraint rope 1 (16) and ankle joint rolling body restraint rope 2 (17) are connected to the ankle joint upper rolling body (503) and the ankle joint lower rolling body (504) of the rolling contact joint, the ankle joint rolling body restraint rope 1 (16) and the ankle joint rolling body restraint rope 2 (17) form an 'X'-shaped intersection structure; The ankle joint upper rolling body (503) of the ankle joint lower rolling contact joint (502) and the knee joint lower rolling body (404) of the knee joint lower rolling contact joint (402) are connected via the lower connecting rod (7) located at the front side, and the ankle joint upper rolling body (503) of the ankle joint upper rolling contact joint (501) and the knee joint lower rolling body (404) of the knee joint upper rolling contact joint (401) are connected via the lower connecting rod (7) located at the rear side.

5. The rope-driven robotic leg based on rolling contact joint according to claim 4, characterized in that: The front and rear side surfaces of the ankle joint upper rolling body (503) and the ankle joint lower rolling body (504) of each rolling contact joint of the ankle joint (5) are respectively connected via ankle joint elastic elements.

6. The rope-driven robotic leg based on rolling contact joint according to claim 4, characterized in that: A pulley 2 (18) is rotatably mounted inside the lower rolling body (404) of the knee joint upper rolling contact joint (401), and the other end of the active rope (12) of the knee joint and ankle joint passes over the pulley 1 (13) on the rear side of the gear-like rolling body (301) of the hip joint upper part and the pulley 2 (18) and is connected to the lower connecting rod (7) located on the front side.

7. The rope-driven robotic leg based on rolling contact joint according to claim 6, characterized in that: The rope-driven mechanical leg further comprises a double-joint spring assembly (22), the double-joint spring assembly (22) comprising a double-joint spring mounting movable substructure and a double-joint spring (2201); the double-joint spring mounting movable substructure comprising a second connecting column (2202) and two second end heads (2203); the lower connecting rod (7) located at the rear side is divided into an upper and lower section; a cavity is provided in the middle of the upper section lower connecting rod and the lower section lower connecting rod (703); coaxial through holes are provided in the middle of the two opposite ends of the upper section lower connecting rod and the lower section lower connecting rod (703); the second connecting column (2202) passes through the through holes of the upper section lower connecting rod and the lower section lower connecting rod (703); the second end heads (2203) are fixed at both ends of the second connecting column (2202); the double-joint spring (2201) is sleeved on the second connecting column (2202); and the double-joint spring (2201) is arranged in the cavity of the lower section lower connecting rod (703).

8. The rope-driven robotic leg based on rolling contact joints according to claim 4, characterized in that: The lower end of the ankle joint lower rolling body (504) of the ankle joint lower rolling contact joint (502) is connected to the sole (23) of the mechanical leg.

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