Rope-driven mechanical leg based on rolling contact joints

Abstract

The invention discloses a rope-driven mechanical leg based on rolling contact joints, and belongs to the technical field of robots. All the drivers are fixedly mounted on the hip joint mounting plate, the hip joint is fixed below the hip joint mounting plate, the hip joint is connected with the knee joint through an upper connecting rod, the knee joint is connected with the ankle joint through two lower connecting rods, and the knee joint, the ankle joint and the two lower connecting rods form a parallelogram-like connecting rod structure; all the joints are rolling contact joints, each rolling contact joint is composed of two rolling bodies which are in contact and rolling connection, one end of each hip joint driving rope is connected with the corresponding driver, and the other end of each hip joint driving rope is connected with the rolling body of the corresponding hip joint; the knee joint and the ankle joint are each provided with two rolling contact joints, and two rolling bodies of each rolling contact joint are connected through two restraining ropes. One end of the knee joint and ankle joint driving rope is connected with the corresponding driver, and the other end bypasses the rolling contact joint of the knee joint and is connected with the lower connecting rod. The stress condition can be optimized, abrasion is reduced, and the service life of the robot is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of robots, and specifically relates to a rope-driven mechanical leg based on a rolling contact joint applied to a bionic foot robot, and more particularly to a transmission structure for optimizing force conditions through a rolling contact joint. Background Art

[0002] At present, common robot mobility modes include wheeled, tracked and legged robots. Compared with other types of mobile robots, legged robots can use isolated ground support instead of the continuous ground support required by wheeled robots, which makes them more maneuverable and adaptable on uneven ground. Legged robots have the characteristics of multiple limbs and multiple degrees of freedom, providing good selectivity and flexibility, and are particularly suitable for working in environments with uncertain factors.

[0003] With the continuous development of legged robots, the types of their most important mechanical leg structures are gradually increasing. The mechanical legs of traditional legged robots are generally driven by motors and reducers. This structure requires the motors and related reducers to be arranged at the joints of the legged robots. Although the mechanical leg structure of this traditional legged robot is simple, it will result in a large leg mass. The motor and reducer of the next-level joint will become an additional load on the previous-level joint, which leads to certain negative results. Most traditional legged robots use traditional pin-type revolute joints. This traditional structure joint has poor force and severe wear, which shortens the life of traditional legged robots.

[0004] The existing legged robot mechanical legs are mostly driven by active motors, and the movement linkage is achieved through control algorithms, which has poor coordination, and to some extent reduces the working efficiency of the legged robot, resulting in low energy utilization. The invention patent application with application publication number CN106985927A and publication date December 30, 2016 discloses "a wire rope driven quadruped or multi-legged robot". Although the robot uses a rope drive to arrange the driver inside the fuselage, which to some extent avoids the problem of large mechanical leg mass, its mechanical leg joints use traditional rigid pin-type revolute joints, which have unsatisfactory force conditions, severe wear, and short service life. Summary of the invention

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

[0006] The present invention is based on animal joints for bionics, and designs a rope-driven foot-type robot mechanical leg based on rolling contact joints. The mechanical leg of the present invention is a two-degree-of-freedom bionic mechanical leg. By imitating the joint structure of animal knees, the rolling contact joint is reasonably designed to replace the traditional pin-type revolute joint, and the constraint rope is used to imitate the cruciate ligament of the knee joint to connect adjacent rolling bodies. The joint of this structure has the advantages of wear resistance and optimized force conditions.

[0007] The present invention utilizes rope drive, added springs and a unique parallelogram-like connecting rod structure by imitating the leg muscle and bone structure of animals to better understand the biological structural principles of animal movement ability, which helps to achieve a driving role in bionics and other aspects.

[0008] To achieve the above object, the technical solution adopted by the present invention is:

[0009] A rope-driven mechanical leg based on a rolling contact joint comprises a hip joint mounting plate, a hip joint, a knee joint, an ankle joint, an upper connecting rod, two lower connecting rods and three drivers; the three drivers are all fixedly mounted on the hip joint mounting plate, and the three drivers are driver one, driver two and driver three;

[0010] The hip joint is fixed below the hip joint mounting plate, 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 two hip joint active ropes is respectively connected to the driver 1 and the driver 3, 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;

[0011] The knee joint and the ankle joint 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 is connected to the rolling contact joint of the knee joint by an upper connecting rod, and the rolling contact joint of the knee joint is connected to the rolling contact joint of the ankle joint by two lower connecting rods arranged front and back, and the knee joint and the ankle joint form a parallelogram connecting rod structure with the two lower connecting rods; one end of the active rope of the knee joint and the ankle joint is connected to the second driver, and the other end of the active rope of the knee joint and the ankle joint bypasses the rolling contact joint of the knee joint and is connected to the lower connecting rod located at the front side.

[0012] Furthermore, the two rolling bodies of the rolling contact joint of the hip joint are respectively a gear-like rolling body at the upper part of the hip joint and a gear-like rolling body at the lower part of the hip joint; the lower arc surface of the gear-like rolling body at the upper part of the hip joint and the upper arc surface of the gear-like rolling body at the lower part of the hip joint are both provided with a plurality of teeth, and the gear-like rolling body at the upper part of the hip joint and the gear-like rolling body at the lower part of the hip joint are meshed with each other;

[0013] The two hip joint active ropes are the front hip joint active rope and the rear hip joint active rope, one end of the front hip joint active rope and the rear hip joint active rope are respectively connected to driver one and driver three, and the other ends of the front hip joint active rope and the rear hip joint active rope are respectively passed around pulley one rotatably installed on the front and rear sides of the gear-like rolling body on the upper part of the hip joint and connected to the front and rear sides of the gear-like rolling body on the lower part of the hip joint.

[0014] Further, the two rolling contact joints of the knee joint are respectively an upper rolling contact joint of the knee joint and a lower rolling contact joint of the knee joint, and the two rolling bodies of the upper rolling contact joint of the knee joint and the lower rolling contact joint of the knee joint are respectively an upper rolling body of the knee joint and a lower rolling body of the knee joint; the two upper rolling bodies of the two rolling contact joints of the knee joint are connected by a knee joint connecting rod; the upper rolling body of the knee joint of the upper rolling contact joint of the knee joint and the gear-like rolling body of the lower hip joint are connected by the upper connecting rod;

[0015] The two restraint ropes connected to the two rolling bodies of each rolling contact joint of the knee joint are knee joint rolling body restraint rope 1 and knee joint rolling body restraint rope 2 respectively. After knee joint rolling body restraint rope 1 and knee joint rolling body restraint rope 2 are connected to the upper rolling body and the lower rolling body of the knee joint of the rolling contact joint, knee joint rolling body restraint rope 1 and knee joint rolling body restraint rope 2 form an 'X' shaped intersection structure.

[0016] Furthermore, the front and rear side surfaces of the upper rolling body of the knee joint and the lower rolling body of each rolling contact joint of the knee joint are respectively connected through a knee joint elastic element.

[0017] Further, the two rolling contact joints of the ankle joint are respectively an upper ankle rolling contact joint and a lower ankle rolling contact joint, and the two rolling bodies of the upper ankle rolling contact joint and the lower ankle rolling contact joint are respectively an upper ankle rolling body and a lower ankle rolling body; the two lower ankle rolling bodies of the two rolling contact joints of the ankle joint are connected by an ankle joint connecting rod;

[0018] The two restraint ropes connected to the two rolling bodies of each rolling contact joint of the ankle joint are ankle joint rolling body restraint rope 1 and ankle joint rolling body restraint rope 2. After the ankle joint rolling body restraint rope 1 and the ankle joint rolling body restraint rope 2 are connected to the ankle joint upper rolling body and the ankle joint lower rolling body of the rolling contact joint, the ankle joint rolling body restraint rope 1 and the ankle joint rolling body restraint rope 2 form an 'X' shaped intersection structure;

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

[0020] Furthermore, the front and rear side surfaces of the upper ankle rolling body and the lower ankle rolling body of each rolling contact joint of the ankle joint are respectively connected through ankle joint elastic elements.

[0021] Furthermore, a pulley 2 is rotatably installed in the lower rolling body of the knee joint of the upper rolling contact joint of the knee joint, and the other end of the active rope of the knee joint and ankle joint passes around the pulley 1 on the rear side of the gear-like rolling body of the upper hip joint and the pulley 2 is connected to the lower connecting rod located on the front side.

[0022] Furthermore, the rope-driven mechanical leg also includes a knee joint spring assembly, which includes a knee joint spring mounting movable pair structure, a knee joint spring, and a knee joint spring movable pair connecting splint; the knee joint spring mounting movable pair structure includes a connecting column 1 and an end 1 fixed at both ends of the connecting column 1, the knee joint spring and the knee joint spring movable pair connecting splint are sleeved on the connecting column 1 from top to bottom and are located between the two end 1s, and the knee joint spring movable pair connecting splint is connected to the knee joint connecting rod;

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

[0024] Furthermore, the rope-driven mechanical leg also includes a double-joint spring assembly, which includes a double-joint spring mounting movable substructure and a double-joint spring; the double-joint spring mounting movable substructure includes two connecting columns and two end caps; the lower connecting rod located on the rear side is divided into two upper and lower sections; the upper lower connecting rod and the lower lower connecting rod are both provided with cavities in the middle; coaxial through holes are provided in the middle of two opposite ends of the upper lower connecting rod and the lower lower connecting rod; the second connecting column passes through the through holes of the upper lower connecting rod and the lower lower connecting rod; two ends of the second connecting column are fixed with end caps; the second connecting column is provided with a double-joint spring, and the double-joint spring is arranged in the cavity of the lower lower connecting rod.

[0025] Furthermore, the lower end of the lower ankle rolling body of the lower ankle rolling contact joint is connected to the sole of the mechanical leg.

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

[0027] 1. Compared with the traditional leg-type robot, the robot leg of the present invention uses a rope drive to keep the driver with a larger mass away from the end actuator. Through reasonable arrangement, the inertia of the robot leg can be reduced and the dynamic performance can be improved. At the same time, the rope drive has the advantages of flexible arrangement and small geometric space occupation, which makes it very suitable for use on the robot leg.

[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 human skeletal joint structure. Compared with the traditional pin-type revolute joint, this structure has the advantages of optimizing the force condition 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 biological legs to maintain the stability of the knee joint and provide a certain support force in static and dynamic movements. The spring installation structure can absorb impact energy during the landing process of the movement, and release energy to assist propulsion during the take-off stage; the double-joint spring can realize energy storage and coordinated knee joint springs, and reduce the dependence on hip joint movement during movement; the knee joint spring and double-joint spring designed by imitating the muscle structure of the leg of the organism can reduce energy consumption and improve the robustness of dynamic movement through the synergistic effect of the two. 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 form 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 helps to improve the life of the mechanical leg to a certain extent. 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, wherein three drivers are 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 bodies of a knee joint or two rolling bodies 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 5It is a structural schematic diagram of the connection between a double-joint spring assembly and an upper lower connecting rod and a lower lower connecting rod located at the rear side.

[0037] The names and reference numerals of the components involved in the above drawings are as follows:

[0038] 1. Mechanical leg mounting plate; 2. Hip joint mounting plate; 3. Hip joint; 301. Gear-like rolling element at the upper part of the hip joint; 302. Gear-like rolling element at the lower part of the hip joint; 4. Knee joint; 401. Rolling contact joint at the upper part of the knee joint; 402. Rolling contact joint at the lower part of the knee joint; 403. Rolling element at the upper part of the knee joint; 404. Rolling element at the lower part of the knee joint; 405. Knee joint connecting rod; 5. Ankle joint; 501. Rolling contact joint at the upper part of the ankle joint; 502. Rolling contact joint at the lower part of the ankle joint; 503. Rolling element at the upper part of the ankle joint; 504. Rolling element at the lower part of the ankle joint; 505. Ankle joint connecting rod; 6. Upper connecting rod; 7. Lower connecting rod; 701. Upper lower connecting rod; 702. Double joint spring mounting splint; 703. Lower lower connecting rod; 8. Driver 1; 9. Driver 2; 10. Active rope for the posterior side of the hip joint; 11. Constraint rope for the rolling body of the knee joint; 12. Active ropes for the knee joint and ankle joint; 13. Pulley 1; 14. Constraint rope for the rolling body of the knee joint; 15. Active rope for the anterior side of the hip joint; 16. Constraint rope for the rolling body of the ankle joint; 17. Constraint rope for the rolling body of the ankle joint; 18. Pulley 2; 19. Knee joint spring assembly; 1901. Knee joint spring; 1902. Connecting column 1; 1903. End 1; 1904. Connecting splint for the moving pair of knee joint spring; 20. Pulley 3; 21. Passive connecting rope for the knee joint spring; 22. Double joint spring assembly; 2201. Double joint spring; 2202. Connecting column 2; 2203. End 2; 23. Plantar of the mechanical leg; 24. Driver 3. DETAILED DESCRIPTION

[0039] Specific implementation method 1: Figure 1-Figure 5 As shown, this embodiment discloses a rope-driven mechanical leg based on rolling contact joints, including 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 sole 11, two lower connecting rods 7 and three drivers (motor is selected); 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;

[0040] One side of the hip joint mounting plate 2 is fixedly connected to the mechanical leg mounting plate 1, and the hip joint 3 is fixed (by screws) below the hip joint mounting plate 2. 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 respectively connected to the driver 1 8 and the driver 3 24, 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.

[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 joint of the hip joint 3 is connected to the rolling contact joint of the knee joint 4 by an upper connecting rod 6, and the rolling contact joint of the knee joint 4 is connected to the rolling contact joint of the ankle joint 5 by two lower connecting rods 7 arranged front and back, the knee joint 4 and the ankle joint 5 form a parallelogram-like connecting rod structure with the two lower connecting rods 7, and the lower end of the ankle joint 5 is connected to the sole 11 of the mechanical leg; one end of the active rope 12 of the knee joint and the ankle joint is connected to the driver 2 9, and the other end of the active rope 12 of the knee joint and the ankle joint bypasses the rolling contact joint of the knee joint 4 and is connected to the lower connecting rod 7 located on the front side.

[0042] Furthermore, 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;

[0043] 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 1 8 and the driver 3 24, the other ends of the front hip joint active rope 15 and the rear hip joint active rope 10 are respectively passed around the pulley 13 rotatably installed on the front and rear sides of the upper hip joint gear-like rolling body 301 and are connected to the front and rear sides of the lower hip joint gear-like rolling body 302 (a connecting rope hole 1 is respectively provided on the front and rear sides of the lower hip joint gear-like rolling body 302, and the other ends of the front hip joint active rope 15 and the rear hip joint active rope 10 are connected to the connecting rope holes 1 on the front and rear sides of the lower hip joint gear-like rolling body 302).

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

[0045] The active rope 10 at the rear of the hip joint and the active rope 15 at the front of the hip joint apply external force to the rolling body of the hip joint to realize the rotation of the kinematic pair. At the same time, the two active ropes arranged on the opposite sides can also realize the change of stiffness in the subsequent control process.

[0046] Further, the two rolling contact joints of the knee joint 4 are respectively an upper knee rolling contact joint 401 and a lower knee rolling contact joint 402, and the two rolling bodies of the upper knee rolling contact joint 401 and the lower knee rolling contact joint 402 are respectively an upper knee rolling body 403 and a lower knee rolling body 404 (the lower end surface of the upper knee rolling body 403 and the upper end surface of the lower knee rolling body 404 are both arc-shaped contact surfaces, and the upper knee rolling body 403 and the lower knee rolling body 404 are in contact with each other through the arc-shaped contact surface to achieve rolling connection); the two upper knee rolling bodies 403 of the two rolling contact joints of the knee joint 4 are connected through a knee joint connecting rod 405; the upper knee rolling body 403 of the upper knee rolling contact joint 401 and the lower hip joint gear-like rolling body 302 are connected through the upper connecting rod 6;

[0047] The two restraint ropes connected to the two rolling bodies of each rolling contact joint of the knee joint 4 are respectively knee joint rolling body restraint rope 11 and knee joint rolling body restraint rope 2 14. After the knee joint rolling body restraint rope 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 11 and the knee joint rolling body restraint rope 2 14 form an 'X' shaped intersection structure.

[0048] This structure imitates the moving joints such as the animal knee joint, uses rolling bodies to imitate the joint bones, and uses restraint ropes to imitate the cruciate ligaments. The existence of the restraint rope can prevent the rolling contact joint from excessive forward or backward movement, and at the same time restrain the up and down movement of the joint to a certain extent.

[0049] Furthermore, the front and rear sides of the upper rolling body 403 and the lower rolling body 404 of each rolling contact joint of the knee joint 4 are respectively connected by a knee joint elastic element (screws are respectively fixed on the front and rear sides of the upper rolling body 403 and the lower rolling body 404, the knee joint elastic element is fixed by the screws, and the two rolling bodies of the rolling contact joint of the knee joint 4 are connected by the knee joint elastic element).

[0050] The front and rear sides of the upper rolling body 403 and the lower rolling body 404 of the knee joint are connected by a knee joint elastic element to realize the restriction of radial sliding and provide a restoring torque to a certain extent, so that the knee joint 4 can return to the initial position after the movement ends (the knee joint elastic element can provide a restoring torque for the rolling body to return to the initial position). 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 rolling contact joint 501 and a lower ankle rolling contact joint 502, and 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 lower end surface of the upper ankle rolling body 503 and the upper end surface of the lower ankle rolling body 504 are both arc-shaped contact surfaces, and the upper ankle rolling body 503 and the lower ankle rolling body 504 are in contact with each other through the arc-shaped contact surface to achieve rolling connection); the two lower ankle 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 restraint ropes connected to the two rolling bodies of each rolling contact joint of the ankle joint 5 are respectively an ankle joint rolling body restraint rope 16 and an ankle joint rolling body restraint rope 2 17. After the ankle joint rolling body restraint rope 16 and the 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 16 and the ankle joint rolling body restraint rope 2 17 form an 'X' shaped intersection structure;

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

[0054] The technical effect of this technical solution is the same as that of the knee joint 4.

[0055] Further, the front and rear sides of the upper ankle rolling body 503 and the lower ankle 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 rolling body 503 and the lower ankle rolling body 504, respectively, and the ankle joint elastic element is fixed by screws, and the two rolling bodies of the rolling contact joint of the ankle joint 5 are connected by the ankle joint elastic element). The technical effect of this technical solution is the same as that of the knee joint 4.

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

[0057] Furthermore, a pulley 2 18 is rotatably installed in the lower rolling body 404 of the upper rolling contact joint 401 of the knee joint, and the other end of the active rope 12 of the knee joint and ankle joint passes around the pulley 13 on the rear side of the upper gear-like rolling body 301 of the hip joint and the pulley 2 18 and is connected to the lower connecting rod 7 located on the front side (the lower connecting rod 7 located on the front side is provided with a connecting rope hole 2, and the other end of the active rope 12 of the knee joint and ankle joint is connected to the connecting rope hole 2).

[0058] The knee joint and ankle joint active rope 12 mainly plays the role of driving the knee joint 4 and the ankle joint 5. Since the knee joint 4 and the ankle joint 5 form a parallelogram-like connecting rod structure with the two lower connecting rods 7, the movement of the knee joint 4 and the ankle joint 5 is coupled, and a single driving rope (knee joint and ankle joint active rope 12) can realize the joint movement of the two joints. Since the legged robot has only two states during the movement, namely, leg lifting and in-situ, the active rope on one side can meet the movement needs.

[0059] Further, the rope-driven mechanical leg also includes a knee joint spring assembly 19, which includes a knee joint spring installation movable pair structure, a knee joint spring 1901 and a knee joint spring movable pair connecting splint 1904; the knee joint spring installation movable pair structure includes a connecting column 1902 and an end 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 sleeved on the connecting column 1902 from top to bottom and are located between the two end 1903 (the two ends of the knee joint spring 1901 are connected to the knee joint spring movable pair connecting splint 1904 and the end 1903), and the knee joint spring movable pair connecting splint 1904 is connected to the knee joint connecting rod 405 (a connecting boss is provided on the front side of the knee joint connecting rod 405, and the connecting boss is fixedly installed in the clamping mouth of the knee joint spring movable pair connecting splint 1904);

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

[0061] A knee joint spring 1901 is provided at the position of the knee joint 4. The knee joint spring 1901 is installed between the mobile substructure and the knee joint spring mobile subconnecting splint 1904 connected to the knee joint connecting rod 405 to form a mobile substructure. The spring constrains the movement of the knee joint 4 in the form of a mobile substructure. The knee joint spring assembly 19 designed by simulating the quadriceps femoris and patellar tendon structure of a biological leg provides elasticity in the direction of the virtual mechanical leg axis, which can maintain the stability and support force of the knee joint 4 in static and dynamic motions. The structure can also absorb impact energy during the bounce landing stage and release energy and assist propulsion during the take-off stage.

[0062] Furthermore, the rope-driven mechanical leg also includes a double-joint spring assembly 22, which includes a double-joint spring mounting movable substructure and a double-joint spring 2201; the double-joint spring mounting movable substructure includes a connecting column 2202 and two end caps 2203, and the lower connecting rod 7 located on the rear side is divided into an upper and lower section, and both the upper lower connecting rod and the lower lower connecting rod 703 have cavities in the middle, and coaxial through holes are provided in the middle of the two opposite ends of the upper lower connecting rod and the lower lower connecting rod 703, and the connecting column 2202 passes through the through holes of the upper lower connecting rod and the lower lower connecting rod 703, and both ends of the connecting column 2202 are fixed with end caps 2203, and the connecting column 2202 is provided with a double-joint spring 2201, and the double-joint spring 2201 is arranged in the cavity of the lower lower connecting rod 703.

[0063] Double-joint springs 2201 are arranged at the knee joint 4 and the ankle joint 5. The double-joint spring 2201 simulates the gastrocnemius-Achilles tendon complex of a biological leg and provides elasticity in the angular direction of the mechanical leg. It can adjust the joint posture under the action of the hip joint torque through additional degrees of freedom, store energy in the double-joint spring 2201, and reduce 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, thereby improving overall energy efficiency.

[0064] The design of knee joint spring 1901 and double joint spring 2201 makes the robotic legs closer to the functional morphology of animal legs, simplifies the control complexity through the passive elastic mechanism to reduce the intervention of active actuators (external devices), and can improve the robustness of dynamic motion to a certain extent.

[0065] The upper lower connecting rod includes an upper lower connecting rod 701 and a double-joint spring mounting clamp 702; the lower end of the upper lower connecting rod 701 is opened, and the lower end of the upper lower connecting rod 701 is set in the clamping mouth of the double-joint spring mounting clamp 702, and the two are connected by screws, and the pulley 18 is rotatably installed in the middle of the top surface of the upper lower connecting rod 701.

[0066] Pulley 13 is arranged on both sides of the rolling body of the upper part of the knee joint 4, and a rope hole is arranged in the lower part, so as to arrange and install the ropes, and the rotation of the knee joint 4 is realized by the cooperation of the retraction and release of the ropes at both ends; a rope hole is arranged on the common connecting rod (lower connecting rod 7) of the knee joint and ankle joint, and pulley 2 18 is installed in the upper split connecting rod (upper lower connecting rod 701) on which the double-joint spring 2201 is installed. The mechanical leg is driven by the active rope 12 of the knee joint and ankle joint to realize the leg-lifting movement, and the leg-lowering movement is realized by replacing the active rope 12 of the knee joint and ankle joint and being realized by the passive spring (knee joint spring 1901).

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

[0068] The design of the knee joint spring 1402 and the double joint spring 802 makes the robotic leg closer to the functional morphology of animal legs, simplifies the control complexity through the passive elastic mechanism to reduce the intervention of the active actuator, and can improve the robustness of dynamic motion to a certain extent.

[0069] The working process is: by extending the front active rope 15 of the hip joint through driver 1 8, contracting the rear active rope 10 of the hip joint through driver 3 24, and contracting the knee joint and ankle joint active rope 12 through driver 2 9, the mechanical leg's leg-retracting and backward-swinging process is realized; by contracting the front active rope 15 of the hip joint through driver 1 8, extending the rear active rope 10 of the hip joint through driver 3 24, extending the knee joint and ankle joint active rope 12 through driver 2 9, and cooperating with the knee joint spring 1901, the mechanical leg's leg-releasing and forward-swinging process is realized.

[0070] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0071] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A rope-driven mechanical leg based on a rolling contact joint, characterized in that: It comprises 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) and three drivers; 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 respectively connected to the driver one (8) and the driver three (24), 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) is connected to the rolling contact joint of the knee joint (4) via an upper connecting rod (6), and the rolling contact joint of the knee joint (4) is connected to the rolling contact joint of the ankle joint (5) via two lower connecting rods (7) arranged front and rear, and the knee joint (4) and the ankle joint (5) form a parallelogram-like 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 bypasses the rolling contact joint of the knee joint (4) and is connected to the lower connecting rod (7) located at the front side.

2. The rope-driven mechanical 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 a gear-like rolling body (301) at the upper part of the hip joint and a gear-like rolling body (302) at the lower part of the hip joint; the lower arc surface of the gear-like rolling body (301) at the upper part of the hip joint and the upper arc surface of the gear-like rolling body (302) at the lower part of the hip joint are both provided with a plurality of teeth, and the gear-like rolling body (301) at the upper part of the hip joint and the gear-like rolling body (302) at the lower part of the hip joint are meshed with each other; The two hip joint active ropes are respectively the front active rope (15) of the hip joint and the rear active rope (10) of the hip joint. One end of the front active rope (15) of the hip joint and the rear active rope (10) of the hip joint are respectively connected to the driver one (8) and the driver three (24). The other ends of the front active rope (15) of the hip joint and the rear active rope (10) of the hip joint are respectively passed around the pulley one (13) rotatably installed 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 mechanical leg based on rolling contact joint according to claim 2, characterized in that: The two rolling contact joints of the knee joint (4) are respectively an upper knee rolling contact joint (401) and a lower knee rolling contact joint (402); the two rolling bodies of the upper knee rolling contact joint (401) and the lower knee rolling contact joint (402) are respectively an upper knee rolling body (403) and a lower knee rolling body (404); the two upper knee 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 rolling body (403) of the upper knee 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 restraining ropes connected to the two rolling bodies of each rolling contact joint of the knee joint (4) are respectively knee joint rolling body restraining rope 1 (11) and knee joint rolling body restraining rope 2 (14). After the knee joint rolling body restraining rope 1 (11) and the knee joint rolling body restraining 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 restraining rope 1 (11) and the knee joint rolling body restraining rope 2 (14) form an 'X' shaped intersection structure.

4. The rope-driven mechanical leg based on rolling contact joint according to claim 3 is 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.

5. The rope-driven mechanical leg based on rolling contact joint according to claim 3 is 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). After the ankle joint rolling body restraint rope 1 (16) and the 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 upper ankle rolling body (503) of the lower ankle rolling contact joint (502) and the lower knee rolling body (404) of the lower knee rolling contact joint (402) are connected via the lower connecting rod (7) located at the front side, and the upper ankle rolling body (503) of the upper ankle rolling contact joint (501) and the lower knee rolling body (404) of the upper knee rolling contact joint (401) are connected via the lower connecting rod (7) located at the rear side.

6. The rope-driven mechanical leg based on rolling contact joint according to claim 5, characterized in that: The front and rear side surfaces 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 respectively connected via ankle joint elastic elements.

7. The rope-driven mechanical leg based on rolling contact joint according to claim 5, characterized in that: A second pulley (18) is rotatably installed in the lower rolling body (404) of the upper rolling contact joint (401) of the knee joint, and the other end of the active rope (12) of the knee joint and ankle joint passes over the first pulley (13) on the rear side of the upper gear-like rolling body (301) of the hip joint and the second pulley (18) to be connected to the lower connecting rod (7) located on the front side.

8. The rope-driven mechanical leg based on rolling contact joint according to claim 3, characterized in that: The rope-driven mechanical leg also includes a knee joint spring assembly (19), which includes a knee joint spring installation movable pair structure, a knee joint spring (1901) and a knee joint spring movable pair connecting splint (1904); the knee joint spring installation movable pair structure includes a connecting column (1902) and an end head (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); A pulley three (20) is rotatably mounted on the front side of the upper rolling body (403) of the lower rolling contact joint (402) of the knee joint, one end of the passive spring connecting rope (21) of the knee joint is connected to the end one (1903) located at the lower end of the connecting column one (1902), and the other end of the passive spring connecting rope (21) of the knee joint passes around the pulley three (20) and is connected to the lower rolling body (404) of the lower rolling contact joint (402) of the knee joint.

9. The rope-driven mechanical leg based on rolling contact joint according to claim 7, characterized in that: The rope-driven mechanical leg also includes a double-joint spring assembly (22), which includes a double-joint spring mounting movable substructure and a double-joint spring (2201); the double-joint spring mounting movable substructure includes 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 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); two ends of the second connecting column (2202) are fixed with two end heads (2203); the second connecting column (2202) is sleeved with a double-joint spring (2201); and the double-joint spring (2201) is arranged in the cavity of the lower section lower connecting rod (703).

10. The rope-driven mechanical leg based on rolling contact joint according to claim 5, 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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