Damping leg structure and quadruped robot

Abstract

The invention relates to a damping leg structure and a quadruped robot, and belongs to the field of quadruped robots. The leg structure comprises a thigh rod, a first flexible joint and a second flexible joint. And a mounting hole is formed in the thigh rod. The first flexible joint comprises a sealing ring, a plurality of first compression springs, a joint ring and a plurality of stop blocks; and the sealing ring is fixedly mounted on one side of the outer edge of the mounting hole and is coaxially aligned with the mounting hole. Due to the fact that the joint ring is connected with the sealing ring through the compression spring, vibration of the thigh rod can be converted into deformation of the compression spring, direct impact between the bevel gear output shaft connected with the joint ring and the first flexible joint is avoided, and the effects of relieving impact force and protecting the robot motion joint are achieved; the joint of the leg structure of the robot can conveniently recover the motion posture after being impacted, and the problem that the joint of the leg structure of the robot is difficult to recover the motion posture after being impacted is solved.

Description

Technical Field

[0001] The present application relates to the field of quadruped robots, and in particular to a shock-absorbing leg structure and a quadruped robot. Background Art

[0002] With the development of quadruped robots, the flexibility of robots has been further improved, and now quadruped robots can be used for simple cargo transportation and terrain searches.

[0003] On the one hand, the electric drive joints of existing quadruped robots are large in size, complex in structure, and heavy in weight, making it difficult to withstand large axial impact forces. The leg structure and joints are easily deformed and damaged by the impact from the external environment, and the leg posture is difficult to automatically recover. On the other hand, the gait of a quadruped robot depends on the freedom and workspace of its single-leg mechanism, and the arrangement of its leg hydraulic power elements will directly affect its reach and bending limit, so careful travel planning is required. Most of the legs of existing quadruped robots adopt a full elbow topology structure, which has certain advantages in climbing, but is not conducive to controlling the quadruped robot to achieve more flexible trajectory planning and obstacle avoidance. Due to the resistance of the hydraulic system and the single degree of freedom of the joints, the shock absorption effect is poor, which restricts the robot's activities in the mountains and forests, and is not conducive to mountain transportation and search.

[0004] There is currently no effective solution to the problem that the joints of existing robot leg structures are difficult to restore their movement posture after being impacted. Summary of the invention

[0005] The present invention provides a shock-absorbing leg structure and a quadruped robot to solve the problem that the joints of the leg structure of the existing robot are difficult to restore the movement posture after being impacted.

[0006] The present invention provides a shock-absorbing leg structure, which includes a thigh rod, a first flexible joint and a second flexible joint. A mounting hole is provided on the thigh rod. The first flexible joint includes a sealing ring, a plurality of first compression springs, a joint ring and a plurality of blocking blocks. The sealing ring is fixedly mounted on one side of the outer edge of the mounting hole and is coaxially aligned with the mounting hole. The inner wall of the sealing ring is raised to form four evenly distributed right-angle flanges, and the right-angle bisector of each right-angle flange passes through the center of the sealing ring. The outer wall of the joint ring is raised to form four evenly distributed rectangular flanges, and adjacent right-angle flanges are connected to the rectangular flanges by a first compression spring. The second flexible joint includes a power output rod, a power input ring and four second compression springs. The power input ring and the joint ring are aligned with the mounting hole of the thigh rod and are used to connect the power input shaft. The power output rod is located on the other side of the outer edge of the mounting hole and is provided with a through hole thereon. The through hole is coaxially aligned with the sealing ring. The four second compression springs are located on the outer circle of the through hole and are connected end to end in a diamond arrangement. Two symmetrical second compression spring connection points are fixed to the outer wall of the power output rod. The outer circle of the power input ring is raised to form a symmetrical plate-like flange. The plate-like flange is limitedly slid along the circumferential direction with the outer wall of the power output rod through a pin, and the pin passes through the other two symmetrical second compression spring connection points.

[0007] Furthermore, the shock-absorbing leg structure also includes a knee joint connecting rod, a connecting pin, a calf rod, a passive foot segment, a self-lubricating radial joint bearing, a connecting axle and a spring rod. The upper part of the calf rod is connected to the lower part of the thigh rod through the joint bearing, and the end of the power output rod away from the through hole is connected to the top side of the calf rod through the knee joint connecting rod. The lower part of the calf rod is rotatably connected to the passive foot segment through a self-lubricating radial joint bearing. The top of the passive foot segment is convex to form a convex plate, which is rotatably connected to one end of the spring rod through the connecting axle, and the other end of the spring rod is rotatably connected to the middle part of the thigh rod.

[0008] Furthermore, the shock-absorbing leg structure also includes an anti-skid foot end, in which a force sensor is built-in, and the anti-skid foot end is fixedly installed at the bottom end of the passive foot segment.

[0009] Furthermore, the shock-absorbing leg structure also includes a thigh protection cover, which is installed on the outer wall of the thigh rod.

[0010] Furthermore, a blocking block is fixed to the two side surfaces of each rectangular flange and right-angle flange respectively, a gap is left between the two blocking blocks of adjacent right-angle flanges and rectangular flanges, and a first compression spring is sleeved on the outer walls of the two blocking blocks.

[0011] Furthermore, the spring bar includes a plastic slide and a symmetrically arranged telescopic assembly;

[0012] The telescopic kit includes a sliding block, a countersunk screw, a fixed support, a linear bearing, a compression spring, a spring lower support and a joint bearing bracket. The spring lower support and the joint bearing bracket are fixedly connected. The linear bearing is connected to the end of the plastic slide tube through the fixed support. A compression spring is sleeved between the linear bearing and the spring lower support, and the two ends of the compression spring are respectively fixed to the linear bearing and the spring lower support. A sliding rod is provided on the spring lower support and the sliding rod is located between the linear bearing and the spring lower support. The sliding block is fixed to the sliding rod by a countersunk screw, and the sliding block slides within a limited position on the inner wall of the plastic slide tube.

[0013] The present invention also provides a quadruped robot, which includes a shock-absorbing leg structure, a main frame and four hip coaxial gear boxes. The shock-absorbing leg structure is the shock-absorbing leg structure described above. The four hip coaxial gear boxes are symmetrical and rotatably mounted on the inner wall of the main frame, and the hip coaxial gear box includes two DC servo motors, a helical gear output shaft, a turbine output shaft, a worm, a first bevel gear, and a second bevel gear, wherein one DC servo motor drives the worm to rotate, the turbine output shaft is rotatably mounted inside the box body and one end of the turbine output shaft passes through the outer wall of the box body, and the worm is meshed with the turbine on the turbine output shaft for transmission, and another DC servo motor drives the first bevel gear to rotate, the helical gear output shaft passes through and is rotatably mounted on the outer wall of the box body, the helical gear output shaft is sleeved on the outer wall of the turbine output shaft and is shorter than the turbine output shaft, the second bevel gear is mounted on the outer wall of the helical gear output shaft, the first bevel gear is meshed with the second bevel gear for transmission, the joint ring of the first flexible joint is connected to the helical gear output shaft by a key, and the power input ring of the second flexible joint is connected to the turbine output shaft by a key.

[0014] Furthermore, the quadruped robot further comprises four linear electric cylinder assemblies arranged corresponding to the coaxial gearboxes of the hips;

[0015] The linear electric cylinder assembly includes a linear electric cylinder, a connecting rod and a connecting pin. The base of the linear electric cylinder is fixedly installed on the inner top of the main frame. One end of the connecting rod is rotatably installed on the outer wall of the box through the connecting pin, and the other end of the connecting rod is rotatably connected to the output end of the linear electric cylinder.

[0016] Furthermore, a binocular camera sensor is installed on the main frame.

[0017] Furthermore, scanning radar and laser radar are installed on the main frame.

[0018] Compared with the related art, the present invention has the following beneficial effects:

[0019] 1. When impacted, the thigh rod will vibrate and deflect, and because the joint ring and the sealing ring are connected by a compression spring, the vibration of the thigh rod will be converted into the deformation of the compression spring, thereby avoiding the direct impact between the bevel gear output shaft connected to the joint ring and the first flexible joint, and playing a role in alleviating the impact force and protecting the robot's motion joints. At the same time, due to the deformation of the compression spring, it is easy for the joints of the robot's leg structure to recover their motion posture after being impacted, solving the problem that the joints of the robot's leg structure are difficult to recover their motion posture after being impacted.

[0020] 2. By compressing or stretching the compression spring and / or the second compression spring, the relatively large impact force is transformed into a gradual force to avoid overload damage to key parts such as the motor, transmission gear and axle.

[0021] 3. The method of using cameras and infrared sensors together was used to design a quadruped robot collection system, which enabled the quadruped robot to obtain more environmental data, solving the technical problem of not being able to collect enough environmental data and perform efficient trajectory planning in complex environments. The existing technology of combining sensor collection information with genetic algorithms - roulette was used to design a quadruped robot path algorithm, solving the problem of difficult robot trajectory planning in mountainous areas.

[0022] 4. The present invention adopts a front elbow and back knee leg topology structure. Compared with the traditional full elbow or full knee type, the front elbow and back knee type adopts a fully symmetrical layout technology, which can more effectively suppress the vibration of the body's center of gravity and movement direction caused by joint control errors. At the same time, the gap design of the leg structure is reasonable, which solves the technical problem of the existing quadruped robot's leg structure being too compact and not flexible enough.

[0023] 5. When the quadruped robot needs to stop at a certain position, the turbine output shaft loses driving force. Due to the self-locking force between the turbine output shaft and the worm, the leg structure of the quadruped robot can be in a self-locking state, which is beneficial for the quadruped robot to stabilize its body shape.

[0024] 6. When the quadruped robot is impacted while crossing the forest, the leg joints of the robot are crooked. At this time, the robot posture can be adjusted by adjusting the linear electric cylinder to achieve auxiliary straightening operation, which improves the operation stability and flexibility of the quadruped robot. In addition, by adjusting the linear electric cylinder, the quadruped robot can also be put into special actions, such as climbing a ramp with many stones, climbing a narrow gap, etc., which improves the flexibility of the robot.

[0025] 7. Due to the symmetrical structure, when the passive foot segment is subjected to pressure, the pressure is transmitted to the joint bearing bracket, and the joint bearing bracket drives the sliding rod to slide in the linear bearing, and the sliding rods on both sides drive the sliding blocks to slide symmetrically in the plastic slide tube, so that the spring rod imitates the function of the surface toe flexor muscles of animals and can achieve bidirectional contraction, so that the leg-foot mechanism has the characteristics of low inertia, while achieving the effects of shock absorption, energy storage and easy obstacle avoidance.

[0026] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a front view of the quadruped robot of the present invention;

[0028] Figure 2 yes Figure 1 Side view of

[0029] Figure 3 yes Figure 2 Schematic diagram of the mid-offset assembly structure;

[0030] Figure 4 It is the front view of the hip coaxial gearbox;

[0031] Figure 5 is a side view of the hip coaxial gearbox;

[0032] Figure 6 It is a top view of the hip coaxial gearbox;

[0033] Figure 7 yes Figure 1 Exploded view of the connection structure between the middle leg structure and the hip coaxial gearbox;

[0034] Figure 8 yes Figure 1 Front view of the mid-leg structure;

[0035] Fig. 9 yes Figure 1 Side view of the mid-leg structure;

[0036] Fig.10 yes Figure 1 Schematic diagram of the structure of the middle spring rod;

[0037] Fig.11 is a structural schematic diagram of the first flexible joint;

[0038] Fig.12 It is a structural schematic diagram of the second flexible joint. DETAILED DESCRIPTION

[0039] In order to more clearly understand the purpose, technical solutions and advantages of the present application, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0040] Unless otherwise defined, the technical terms or scientific terms involved in this application shall have the general meaning understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the", "these" and the like in this application do not represent quantitative restrictions, and they can be singular or plural. The terms "include", "comprise", "have" and any variants thereof involved in this application are intended to cover non-exclusive inclusions; for example, a process, method and system, product or device comprising a series of steps or modules (units) is not limited to the listed steps or modules (units), but may include unlisted steps or modules (units), or may include other steps or modules (units) inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether directly or indirectly. The "multiple" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, "A and / or B" can mean: A exists alone, A and B exist at the same time, and B exists alone. Usually, the character " / " indicates that the objects associated with each other are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0041] The shock-absorbing leg structure and the quadruped robot of the present invention are specifically described below through an embodiment.

[0042] In this embodiment, a quadruped robot is provided. Figure 1 , which includes a shock-absorbing leg structure 2, a main frame 111 and four hip coaxial gear boxes 6. This embodiment adopts a front elbow and rear knee leg topology structure. Compared with the traditional full elbow or full knee, the full symmetrical layout technology adopted by the front elbow and rear knee can more effectively suppress the vibration of the body center of gravity and movement direction caused by joint control errors. At the same time, the gap design of the leg structure 2 is reasonable, which solves the technical problem that the existing quadruped robot is not flexible enough due to the overly compact leg structure.

[0043] See also Figure 2, wherein the main frame 111 is a rectangular parallelepiped skeleton structure, which includes an upper top plate, a lower top plate and a plurality of support columns connecting and fixing the upper top plate and the lower top plate. In order to improve the ability of the quadruped robot to collect information and plan the route, further, a binocular camera sensor 1, a scanning radar 3 and a laser radar 5 are installed on the main frame 111. The method of using both cameras and infrared sensors is used to design the quadruped robot collection system, so that the quadruped robot can obtain more environmental data, solving the technical problem that it is impossible to collect enough environmental data and perform efficient trajectory planning in complex environments. The method of combining sensor collection information with genetic algorithm-roulette in the prior art is used to design the path algorithm of the quadruped robot, solving the problem of difficult trajectory planning of the robot in mountainous areas.

[0044] See also Figure 2 and Figure 3 In addition, four hip coaxial gear boxes 6 are symmetrically and rotatably mounted on the inner wall of the main frame 111. Figure 1 For example, two hip coaxial gear boxes 6 are symmetrically installed on the left and right inner walls of the main frame 111, and the two hip coaxial gear boxes 6 on the front side of the main frame 111 are also symmetrical with the two hip coaxial gear boxes 6 on the rear side of the main frame 111. The hip coaxial gear box 6 provides four power outputs on the front and rear sides of the main frame 111, and controls the four legs of the quadruped robot to move respectively. However, since the hip coaxial gear box 6 is rotatably installed in the main frame 111, the hip coaxial gear box 6 will shake and be unstable when the robot moves. In order to reduce the shaking and improve the stability, four linear electric cylinder assemblies corresponding to the hip coaxial gear box 6 are arranged on the inner top in the middle of the main frame 111 to control the offset rotation of the hip coaxial gear box 6. Specifically, the linear electric cylinder assembly includes a linear electric cylinder 4, a connecting rod 41 and a connecting pin 42. The base of the linear electric cylinder 4 is fixedly mounted on the inner top of the main frame 111. One end of the connecting rod 41 is rotatably mounted on the outer wall of the box body through the connecting pin 42. The other end of the connecting rod 41 is rotatably connected to the output end of the linear electric cylinder 4. The advantage of this is that the linear electric cylinder 4 controls the rotational offset of the box body by controlling the connecting rod 41, thereby controlling the rotational offset of the hip coaxial gearbox 6, thereby controlling the direction and angle change of the leg output end of the hip coaxial gearbox 6. When the quadruped robot is impacted while crossing the forest, the leg joints of the robot are skewed. At this time, the auxiliary straightening operation of the robot posture can be achieved by adjusting the linear electric cylinder 4, thereby improving the operating stability and flexible operability of the quadruped robot. In addition, by adjusting the linear electric cylinder 4, the quadruped robot can also be put into special actions, such as climbing a ramp with many stones, climbing a narrow gap, etc., thereby improving the flexibility of the robot.

[0045] See also Figure 4 , Figure 5 and Figure 6 In addition, in order to better analyze the power output of the hip coaxial gearbox 6, please refer to Figures 8 to 10 The hip coaxial gearbox 6 includes two DC servo motors 6.11, a helical gear output shaft 6.21, a turbine output shaft 6.22, a worm 6.6, a housing, a first bevel gear and a second bevel gear 6.23. The two DC servo motors 6.11 are symmetrically installed in the housing, one of the DC servo motors 6.11 (motor No. 1) drives the worm 6.6 to rotate, the turbine output shaft 6.22 is rotatably installed inside the housing and one end of the turbine output shaft 6.22 passes through the outer wall of the housing, the worm 6.6 is meshed with the turbine on the turbine output shaft 6.22 for transmission, and the other DC servo motor 6.11 (motor No. 2) drives the first bevel gear to rotate, and No. 1 and No. 2 here are only used to distinguish the DC servo motors 6.11. The bevel gear output shaft 6.21 penetrates and is rotatably mounted on the outer wall of the housing, the bevel gear output shaft 6.21 is sleeved on the outer wall of the turbine output shaft 6.22 and is shorter than the turbine output shaft 6.22, the second bevel gear 6.23 is mounted on the outer wall of the bevel gear output shaft 6.21, the first bevel gear and the second bevel gear 6.23 are meshed and driven, the joint ring of the first flexible joint 7 is connected to the bevel gear output shaft 6.21 by a key, and the power input ring 2.2.2 of the second flexible joint 2.2 is connected to the turbine output shaft 6.22 by a key. The key point is that when the quadruped robot needs to stop at a certain position, the turbine output shaft 6.22 loses the driving force, and due to the self-locking force between the turbine output shaft 6.22 and the worm 6.6, the leg structure of the quadruped robot can be in a self-locking state, which is conducive to the stability of the quadruped robot.

[0046] In actual application, a gear box 6.7 is respectively arranged between the two DC servo motors 6.11 and the worm 6.6 and the first bevel gear to match the speed of the rotating shaft, and the output shafts of the two DC servo motors 6.11 are connected to the gear box 6.7 through a coupling 6.9. A planetary reducer 6.10 is arranged between the DC servo motor 6.11 and the coupling 6.9. Specifically, the execution structure of the hip coaxial gearbox 6 is composed of a deep groove ball bearing 6.1, a front end cover 6.2 of the gearbox, a main shaft end cover 6.4, a worm 6.6, a felt ring 6.14, a helical gear output shaft 6.21, a worm gear output shaft 6.22 and a second bevel gear 6.23. The internal drive structure of the hip coaxial gearbox 6 is composed of a coupling 6.9, a planetary reducer 6.10, a DC servo motor 6.11, a rear fixing frame 6.12 and a boss 6.13. The hip coaxial gearbox 6 is installed with angular contact ball bearings 6.1 at the front and rear. The installation of angular contact ball bearings 6.1 is designed according to the standard of inner diameter interference fit and outer diameter clearance fit. The rolling motion is realized by the linear electric cylinder control 4 fixed on the main frame 111. One end of the worm 6.6 is directly installed on the output shaft of the DC servo motor 6.11 through the coupling 6.9. In order to overcome the transmission force, the other end of the worm 6.6 is pressed with a deep groove ball bearing 6.16 to ensure that both forward and reverse transmission have support force. One end of the worm wheel is supported by the deep groove ball bearing 6.15 on the box body, and the other end is installed on the shoulder support, and it directly outputs power as the inner shaft. The first bevel gear is installed on the output shaft of the DC servo motor 6.11 through the key and the coupling 6.9, and the second bevel gear 6.23 is installed on the box body and outputs as an external shaft. The force analysis of the second bevel gear 6.23 shows that it is only subjected to transmission force in one direction during transmission, so it does not need to be supported and pressed at the other end. In order to reduce the transmission gap and improve the transmission efficiency, the hip coaxial gearbox 6 adopts a primary transmission, that is, only one gear is transmitted. The selected DC servo motor 6.11 is equipped with a planetary reducer 6.10, and the reduction ratios are 26 and 156 respectively. Among them, the rated output torque of the planetary reducer 6.10 with a reduction ratio of 26 is much smaller than that of the planetary reducer 6.10 with a reduction ratio of 156. In order to make their rated torques similar, the reduction transmission needs to be further designed. If ordinary straight teeth or helical teeth are used to achieve transmission, the space occupied will be quite large. Therefore, considering the compact worm gear transmission, the reduction ratio is selected as 10, and it also has the function of reverse self-locking. The motor with a reduction ratio of 156 directly adopts a bevel gear transmission with a transmission ratio of 1 and an angle of 90°.

[0047] See also Figure 7In general, when the quadruped robot moves, the No. 1 motor drives the worm 6.6 to rotate, and the worm 6.6 drives the turbine to rotate, thereby driving the turbine output shaft 6.22 to rotate. Since the power input ring 2.2.2 of the second flexible joint 2.2 is connected to the turbine output shaft 6.22 by a key, the rotation of the turbine output shaft 6.22 will drive the power input ring 2.2.2 to rotate, thereby driving the rotation of the shaft connected to the knee joint, and realizing the movement of the quadruped robot knee joint. The No. 2 motor drives the first bevel gear to rotate, and the first bevel gear drives the second bevel gear 6.23 to rotate. Since the joint ring of the first flexible joint 7 is connected to the helical gear output shaft 6.21 by a key, the rotation of the second bevel gear 6.23 will drive the helical gear output shaft 6.21 to rotate, thereby driving the joint ring and the hip joint shaft connected to the joint ring to rotate, thereby controlling the movement of the quadruped robot by controlling the No. 1 motor and the No. 2 motor.

[0048] See also Figures 7 to 12 In this embodiment, a shock-absorbing leg structure 2 of the above-mentioned quadruped robot is also provided, which includes a thigh rod 2.4, a first flexible joint 7 and a second flexible joint 2.2.

[0049] Among them, see Figure 8 and Fig.11 , a mounting hole is provided on the thigh rod 2.4. The first flexible joint 7 includes a sealing ring 7.1, a plurality of first compression springs 7.2, a joint ring and a plurality of blocking blocks 7.3. The first flexible joint 7 has a buffering effect on the movement of the quadruped robot, preventing the movement of the thigh rod 2.4 from causing excessive impact on the hip coaxial gearbox 6. The sealing ring 7.1 is fixedly mounted on one side of the outer edge of the mounting hole and is coaxially aligned with the mounting hole. The inner wall of the sealing ring 7.1 is raised to form four evenly distributed right-angle flanges, and the right-angle bisector of each right-angle flange passes through the center of the sealing ring. The outer wall of the joint ring is raised to form four evenly distributed rectangular flanges, and adjacent right-angle flanges are connected to the rectangular flange by a first compression spring 7.2. When impacted, the thigh rod 2.4 will vibrate and deflect, and since the joint ring and the sealing ring 7.1 are connected by the compression spring 7.2, the vibration of the thigh rod 2.4 will be converted into the deformation of the compression spring 7.2, thereby avoiding the direct impact between the bevel gear output shaft 6.21 connected to the joint ring and the first flexible joint 7, thereby alleviating the impact force and protecting the robot's motion joints. At the same time, due to the deformation of the compression spring 7.2, it is easy for the joints of the robot's leg structure to recover their motion posture after being impacted, thereby solving the problem that the joints of the robot's leg structure are difficult to recover their motion posture after being impacted.

[0050] In order to improve the connection strength of the joint ring, further, a blocking block 7.3 is fixed on both sides of each rectangular flange and the right-angle flange, a gap is left between the two blocking blocks 7.3 of adjacent right-angle flanges and rectangular flanges, and a first compression spring 7.2 is connected to the outer walls of the two blocking blocks 7.3, thereby improving the stability of the joint ring during movement.

[0051] Also, see Fig.12 The second flexible joint 2.2 includes a power output rod 2.2.1, a power input ring 2.2.2 and four second compression springs 2.2.3. The power input ring 2.2.2 and the joint ring are aligned with the mounting hole of the thigh rod 2.4 and are used to connect the power input shaft. The power output rod 2.2.1 is located on the other side of the outer edge of the mounting hole and is provided with a through hole, and the through hole is coaxially aligned with the sealing ring 7.1. The four second compression springs 2.2.3 are located on the outer circle of the through hole and are connected end to end in a diamond arrangement, wherein two symmetrical second compression spring 2.2.3 connection points are fixed to the outer wall of the power output rod 2.2.1, and the outer circle of the power input ring 2.2.2 is raised to form a symmetrical plate-like flange, which is limitedly slid along the circumferential direction with the outer wall of the power output rod 2.2.1 through a latch, and the latch passes through the other two symmetrical second compression spring 2.2.3 connection points. When impacted, the thigh bar 2.4 will vibrate and deflect, and because the plate-shaped flange of the power input ring 2.2.2 is connected to the second compression spring 2.2.3, when impacted, the vibration deflection of the second flexible joint 2.2 will be converted into deformation of the second compression spring 2.2.3 and rotation of the power input ring 2.2.2, thereby avoiding direct impact between the power input ring 2.2.2 and the thigh bar 2.4, and playing a protective role on the leg structure. Figure 3 Furthermore, the shock-absorbing leg structure also includes a knee joint connecting rod 2.3, a connecting pin 2.5, a calf rod 2.6, a passive foot segment 2.7, a self-lubricating radial joint bearing 2.9, a connecting small shaft 2.10 and a spring rod 2.11. The upper part of the calf rod 2.6 is connected to the lower part of the thigh rod 2.4 through a joint bearing, and the end of the power output rod 2.2.1 away from the through hole is connected to the top side of the calf rod 2.6 through the knee joint connecting rod 2.3. The lower part of the calf rod 2.6 is rotatably connected to the passive foot segment 2.7 through the self-lubricating radial joint bearing 2.9. The top of the passive foot segment 2.7 is convexly protruded to form a convex plate, which is rotatably connected to one end of the spring rod 2.11 through the connecting small shaft 2.10, and the other end of the spring rod 2.11 is rotatably connected to the middle part of the thigh rod 2.4.

[0052] The rotation of the joint ring is controlled by the bevel gear output shaft 6.21 to control the movement of the thigh rod 2.4, and the rotation of the power input ring 2.2.2 is controlled by the turbine output shaft 6.22 to control the rotation of the second flexible joint 2.2 and drive the knee joint connecting rod 2.3 to rotate, thereby realizing the rotation of the calf rod 2.6 and the passive foot segment 2.7, thereby realizing the movement of the shock-absorbing leg structure.

[0053] See also Figure 8 The thigh bar 2.4, the passive foot segment 2.7, the calf bar 2.6 and the spring bar 2.11 form a parallelogram structure. The leg design is based on the principle that the four-bar three-segment structure has a large reachable space and is simple to control, which can ensure the fast running and flexibility of the quadruped robot. The leg configuration adopts the front elbow and back knee type as a typical diagonal gait, and the speed range is large, which can be fast or slow. The diagonal foot is completely symmetrical about the center of the robot when moving, which significantly weakens the inertia force of the leg movement, so that the robot has better controlled performance and has many usage scenarios, which can basically cover most of the above application scenarios, especially suitable for rugged road environments.

[0054] The basic principle of the first flexible joint 7 and the second flexible joint 2.2 is as follows: the first flexible joint 7 and the second flexible joint 2.2 are concentrically assembled, the first flexible joint 7 is connected to the thigh output, and the second flexible joint 2.2 is used to connect the calf output. The power and torque are transmitted through the corresponding shaft, first transmitted to the input end of the first flexible joint 7 and / or the second flexible joint 2.2 through the key connection, and then the relatively large impact force is transformed into a gradual force through the compression or extension of the compression spring 7.2 and / or the second compression spring 2.2.3, so as to avoid overloading the key parts such as the motor and the transmission gear and the axle. The energy accumulated in the compression spring 7.2 and / or the second compression spring 2.2.3 will be gradually transmitted to the output end, and then transmitted to the thigh rod by the first flexible joint 7 and / or transmitted to the knee joint output rod by the second flexible joint 2.2, and then the calf is driven to move through the connecting rod, thereby realizing the movement of the entire quadruped robot.

[0055] Since the vibrations to which the first flexible joint 7 and the second flexible joint 2.2 are subjected when the robot moves are low-frequency vibrations, the compression spring 7.2 and the second compression spring 2.2.3 can effectively reduce vibrations and impacts without the need for a damper.

[0056] In order to improve the anti-skid performance and action data monitoring capability of the four-speed robot moving in the mountains and forests, the shock-absorbing leg structure further includes an anti-skid foot end 2.8, the anti-skid foot end 2.8 has a built-in force sensor, and the anti-skid foot end 2.8 is fixedly installed at the bottom end of the passive foot segment 2.7.

[0057] In order to improve the anti-scratch and impact resistance of the leg structure, the shock-absorbing leg structure further includes a thigh protection cover 2.1, which is installed on the outer wall of the thigh rod 2.4.

[0058] See also Fig.10 The spring rod 2.11 can be a robot spring rod commonly used in the prior art. In order to improve the leg contraction performance of the quadruped robot, the structure of the spring rod 2.11 can be specially designed. The spring rod 2.11 includes a plastic slide 2.11.8 and a symmetrically arranged telescopic kit. The telescopic kit includes a sliding block 2.11.7, a countersunk screw 2.11.6, a fixed support 2.11.5, a linear bearing 2.11.4, a compression spring 2.11.3, a lower spring support 2.11.2 and a joint bearing bracket 2.11.1. The lower spring support 2.11.2 and the joint bearing bracket 2.11.1 are fixedly connected. The linear bearing 2.11.4 is connected to the end of the plastic slide 2.11.8 through the fixed support 2.11.5. The linear bearing 2.11.4 is connected to the lower spring support 2.11.2. A compression spring 2.11.3 is sleeved between the supports 2.11.2, and the two ends of the compression spring 2.11.3 are respectively fixed to the linear bearing 2.11.4 and the lower spring support 2.11.2. A sliding rod is provided on the lower spring support 2.11.2 and the sliding rod is located between the linear bearing 2.11.4 and the lower spring support 2.11.2. The sliding block 2.11.7 is fixed to the sliding rod by a countersunk screw 2.11.6, and the sliding block 2.11.7 slides within a limited position on the inner wall of the plastic slide cylinder 2.11.8. Due to the symmetrical structure, when the passive foot segment 2.7 is subjected to pressure, the pressure is transmitted to the joint bearing bracket 2.11.1, and the joint bearing bracket 2.11.1 drives the sliding rod to slide in the linear bearing 2.11.4, and the sliding rods on both sides drive the sliding block 2.11.7 to slide symmetrically in the plastic slide tube 2.11.8, so that the spring rod 2.11 imitates the function of the surface toe flexor muscle of the animal and can realize bidirectional contraction, so that the leg-foot mechanism has the characteristics of low inertia, and at the same time achieves the effects of shock absorption, energy storage and easy obstacle avoidance.

[0059] It should be understood that the specific embodiments described herein are only used to explain the application, rather than to limit it. Based on the embodiments provided in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of this application.

[0060] Obviously, the drawings are only some examples or embodiments of the present application. For ordinary technicians in the field, the present application can also be applied to other similar situations based on these drawings without creative work. In addition, it is understandable that although the work done in this development process may be complicated and lengthy, for ordinary technicians in the field, certain changes in design, manufacturing or production based on the technical content disclosed in this application are only conventional technical means and should not be regarded as insufficient content disclosed in this application.

Claims

1. A shock-absorbing leg structure, characterized in that: include: A thigh rod (2.4) having a mounting hole thereon; A first flexible joint (7), comprising a sealing ring (7.1), a plurality of first compression springs (7.2), a joint ring and a plurality of blocking blocks (7.3); the sealing ring (7.1) is fixedly mounted on one side of the outer edge of the mounting hole and is coaxially aligned with the mounting hole; the inner wall of the sealing ring (7.1) is raised to form four evenly distributed right-angle flanges, the right-angle bisector of each right-angle flange passes through the center of the sealing ring; the outer wall of the joint ring is raised to form four evenly distributed rectangular flanges, and adjacent right-angle flanges are connected to the rectangular flange via a first compression spring (7.2); The second flexible joint (2.2) comprises a power output rod (2.2.1), a power input ring (2.2.2) and four second compression springs (2.2.3). The power input ring (2.2.2) and the joint ring are aligned with the mounting hole of the thigh rod (2.4) and are used to connect the power input shaft. The power output rod (2.2.1) is located on the other side of the outer edge of the mounting hole and is provided with a through hole. The through hole is coaxially aligned with the sealing ring (7.1). The four second compression springs (2.2.3) are located on the outer circle of the through hole and are connected end to end in a diamond arrangement. Two symmetrical connection points of the second compression springs (2.2.3) are fixed to the outer wall of the power output rod (2.2.1). The outer circle of the power input ring (2.2.2) is raised to form a symmetrical plate-shaped flange. The plate-shaped flange is limitedly slidable along the circumferential direction with the outer wall of the power output rod (2.2.1) through a latch, and the latch passes through the other two symmetrical connection points of the second compression springs (2.2.3).

2. The shock-absorbing leg structure according to claim 1, characterized in that: The shock-absorbing leg structure also includes a knee joint connecting rod (2.3), a connecting pin (2.5), a shank rod (2.6), a passive foot segment (2.7), a self-lubricating radial joint bearing (2.9), a connecting small shaft (2.10) and a spring rod (2.11); the upper part of the shank rod (2.6) is connected to the lower part of the thigh rod (2.4) through the joint bearing; the end of the power output rod (2.2.1) away from the through hole is connected to the top side of the shank rod (2.6) through the knee joint connecting rod (2.3); the lower part of the shank rod (2.6) is rotatably connected to the passive foot segment (2.7) through the self-lubricating radial joint bearing (2.9); the top of the passive foot segment (2.7) is convexly protruded to form a convex plate; the convex plate is rotatably connected to one end of the spring rod (2.11) through the connecting small shaft (2.10); the other end of the spring rod (2.11) is rotatably connected to the middle part of the thigh rod (2.4).

3. The shock-absorbing leg structure according to claim 2, characterized in that: The shock-absorbing leg structure also includes an anti-skid foot end (2.8), the anti-skid foot end (2.8) has a built-in force sensor, and the anti-skid foot end (2.8) is fixedly installed at the bottom end of the passive foot segment (2.7).

4. The shock-absorbing leg structure according to claim 1, characterized in that: The shock-absorbing leg structure also includes a thigh protection cover (2.1), which is mounted on the outer wall of the thigh rod (2.4).

5. The shock-absorbing leg structure according to claim 1, characterized in that: A blocking block (7.3) is fixed to the two side surfaces of each rectangular flange and right-angle flange, a gap is left between the two blocking blocks (7.3) of adjacent right-angle flanges and rectangular flanges, and a first compression spring (7.2) is sleeved on the outer walls of the two blocking blocks (7.3).

6. The shock-absorbing leg structure according to claim 2, characterized in that: The spring rod (2.11) comprises a plastic slide tube (2.11.8) and a symmetrically arranged telescopic set; The telescopic kit includes a sliding block (2.11.7), a countersunk screw (2.11.6), a fixed support (2.11.5), a linear bearing (2.11.4), a compression spring (2.11.3), a spring lower support (2.11.2) and a joint bearing bracket (2.11.1), wherein the spring lower support (2.11.2) and the joint bearing bracket (2.11.1) are fixedly connected, the linear bearing (2.11.4) is connected to the end of the plastic slide cylinder (2.11.8) through the fixed support (2.11.5), and the linear bearing (2.11.4) is connected to the spring A compression spring (2.11.3) is sleeved between the lower supports (2.11.2), and the two ends of the compression spring (2.11.3) are respectively fixed to the linear bearing (2.11.4) and the spring lower support (2.11.2), a sliding rod is arranged on the spring lower support (2.11.2) and the sliding rod is located between the linear bearing (2.11.4) and the spring lower support (2.11.2), a sliding block (2.11.7) is fixed to the sliding rod by a countersunk screw (2.11.6), and the sliding block (2.11.7) slides in a limited position on the inner wall of the plastic slide cylinder (2.11.8).

7. A quadruped robot, characterized in that: include: A shock-absorbing leg structure, which is the shock-absorbing leg structure according to any one of claims 1 to 6; Main frame (111); Four hip coaxial gear boxes (6) are symmetrically mounted in pairs and rotatably mounted on the inner wall of the main frame (111). The hip coaxial gear box (6) comprises two DC servo motors (6.11), a helical gear output shaft (6.21), a turbine output shaft (6.22), a worm (6.6), a first bevel gear, a second bevel gear (6.23) and a housing. The two DC servo motors (6.11) are symmetrically mounted in the housing. One of the DC servo motors (6.11) drives the worm (6.6) to rotate. The turbine output shaft (6.22) is rotatably mounted inside the housing and one end of the turbine output shaft (6.22) passes through the outer wall of the housing. The worm (6.6) and the turbine output shaft (6.22) are connected to each other. ) is meshed with the turbine on the housing, another DC servo motor (6.11) drives the first bevel gear to rotate, the bevel gear output shaft (6.21) penetrates and is rotatably mounted on the outer wall of the housing, the bevel gear output shaft (6.21) is sleeved on the outer wall of the turbine output shaft (6.22) and is shorter than the turbine output shaft (6.22), the second bevel gear (6.23) is mounted on the outer wall of the bevel gear output shaft (6.21), the first bevel gear and the second bevel gear (6.23) are meshed with each other for transmission, the joint ring of the first flexible joint (7) is connected to the bevel gear output shaft (6.21) by a key, and the power input ring (2.2.2) of the second flexible joint (2.2) is connected to the turbine output shaft (6.22) by a key.

8. The quadruped robot according to claim 7, characterized in that: The quadruped robot also includes four linear electric cylinder assemblies arranged corresponding to the coaxial gear boxes (6) of the hips; The linear electric cylinder assembly comprises a linear electric cylinder (4), a connecting rod (41) and a connecting pin (42); the base of the linear electric cylinder (4) is fixedly mounted on the inner top of the main frame (111); one end of the connecting rod (41) is rotatably mounted on the outer wall of the box body through the connecting pin (42); and the other end of the connecting rod (41) is rotatably connected to the output end of the linear electric cylinder (4).

9. The quadruped robot according to claim 7, characterized in that: A binocular camera sensor (1) is installed on the main frame (111).

10. The quadruped robot according to claim 7, characterized in that: A scanning radar (3) and a laser radar (5) are installed on the main frame (111).

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