Damping leg structure and quadruped robot

Abstract

The application relates to a shock-absorbing leg structure and a quadruped robot, and belongs to the quadruped robot field. The leg structure comprises a thigh rod, a first flexible joint and a second flexible joint. The thigh rod is provided with a mounting hole. The first flexible joint comprises a sealing ring, a plurality of first compression springs, a joint ring and a plurality of blocking blocks, the sealing ring is fixedly installed on one side of the outer edge of the mounting hole and coaxially aligned with the mounting hole. Since the joint ring is connected with the sealing ring through the compression springs, the vibration of the thigh rod is converted into the deformation of the compression springs, so that the direct impact of the bevel gear output shaft connected with the joint ring on the first flexible joint is avoided, the impact force is relieved, the robot movement joint is protected, and the problem that the joint of the robot leg structure is difficult to restore the movement posture after being impacted is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of quadruped robots, and particularly relates to a shock-absorbing leg structure and a quadruped robot. BACKGROUND

[0002] With the development of quadruped robots, the flexibility of the robots is further improved, and now simple cargo transportation and terrain search can be performed by using the quadruped robots.

[0003] On the one hand, the existing quadruped robot electric drive joint is large in size, complex in structure, and heavy in weight, and is difficult to withstand a large axial impact force. The leg structure and joint are easily deformed and damaged by impact from the external environment, and the leg posture is difficult to automatically restore. On the other hand, the gait of the quadruped robot depends on the degree of freedom and working space of its single leg mechanism, and the arrangement of the leg hydraulic power element directly affects its reachable range and bending limit, so careful travel planning must be performed. The leg of the existing quadruped robot mostly adopts a full elbow type topology structure, which has certain advantages in climbing, but is not conducive to controlling the quadruped robot to achieve relatively flexible trajectory planning and obstacle avoidance. Due to the resistance of the hydraulic system and the singularity of the joint degree of freedom, the shock-absorbing effect is poor, which limits the movement of the robot in the mountains and forests, and is not conducive to mountain transportation and search.

[0004] At present, there is no effective solution to the problem that the joint of the leg structure of the existing robot is difficult to restore the motion posture after being impacted. SUMMARY

[0005] The present application provides a shock-absorbing leg structure and a quadruped robot to solve the problem that the joint of the leg structure of the existing robot is difficult to restore the motion posture after being impacted.

[0006] This invention provides a shock-absorbing leg structure, comprising a thigh bar, a first flexible joint, and a second flexible joint. The thigh bar has mounting holes. The first flexible joint includes a sealing ring, several first compression springs, a joint ring, and several blocking blocks. The sealing ring is fixedly mounted on one side of the outer edge of the mounting hole and coaxially aligned with the mounting hole. The inner wall of the sealing ring protrudes to form four evenly distributed right-angled flanges, the right-angle bisector of which passes through the center of the sealing ring. The outer wall of the joint ring protrudes to form four evenly distributed rectangular flanges. Adjacent right-angled flanges and rectangular flanges are connected 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 holes 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 has a through hole, which is coaxially aligned with the sealing ring. The four second compression springs are located on the outer ring of the through hole and are arranged in a diamond pattern and connected end to end. Two of the symmetrical second compression springs are fixed to the outer wall of the power output rod at their connection points. The outer ring of the power input ring protrudes to form a symmetrical plate-shaped flange. The plate-shaped flange is limited and slids along the circumferential direction with the outer wall of the power output rod by a pin, and the pin passes through the connection points of the other two symmetrical second compression springs.

[0007] Furthermore, the shock-absorbing leg structure also includes a knee joint connecting rod, a connecting pin, a lower leg rod, a passive foot segment, a self-lubricating radial joint bearing, a connecting shaft, and a spring rod. The upper part of the lower leg rod is connected to the lower part of the thigh rod via the joint bearing. The end of the power output rod away from the through hole is connected to the top side of the lower leg rod via the knee joint connecting rod. The lower part of the lower leg rod is rotatably connected to the passive foot segment via the self-lubricating radial joint bearing. The top of the passive foot segment protrudes to form a convex plate. The convex plate is rotatably connected to one end of the spring rod via the connecting shaft. 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-slip foot end, which has a built-in force sensor and is fixedly installed at the bottom of the passive foot segment.

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

[0010] Furthermore, a blocking block is fixed on each side of each rectangular flange and right-angle flange, and 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 wall of the two blocking blocks.

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

[0012] The telescopic kit comprises a sliding block, a countersunk screw, a fixed support, a linear bearing, a compression spring, a spring lower support and a joint bearing support, the spring lower support and the joint bearing support are fixedly connected, the linear bearing is connected with the end of the plastic sliding cylinder through the fixed support, the compression spring is sleeved between the linear bearing and the spring lower support, and the two ends of the compression spring are fixed with the linear bearing and the spring lower support respectively, the spring lower support is provided with a sliding rod and the sliding rod is located between the linear bearing and the spring lower support, the sliding block is fixed with the sliding rod through the countersunk screw, and the sliding block is limitedly slid in the inner wall of the plastic sliding cylinder.

[0013] The application further provides a quadruped robot, which comprises a shock-absorbing leg structure, a main body frame and four hip coaxial gear boxes.

[0014] Further, the quadruped robot further comprises four linear motor cylinder assemblies corresponding to the hip coaxial gear boxes.

[0015] The linear motor cylinder assembly comprises a linear motor cylinder, a connecting rod and a connecting pin, the base of the linear motor cylinder is fixedly installed on the inner top of the main body 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 with the output end of the linear motor cylinder.

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

[0017] Further, a scanning radar and a laser radar are installed on the main body frame.

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

[0019] 1. When impacted, the thigh rod will vibrate and deviate, and due to the connection of the joint ring and the sealing ring through the compression spring, the vibration of the thigh rod will be converted into the deformation of the compression spring, so as to avoid the direct impact of the bevel gear output shaft connected with the joint ring on the first flexible joint, play a role in relieving the impact force and protecting the robot movement joint, and due to the deformation of the compression spring, the robot leg structure can be restored to the movement posture after being impacted, and the problem that the robot leg structure is difficult to restore to the movement posture after being impacted is solved.

[0020] 2. By compressing or stretching the compression spring and / or the second compression spring, a relatively large impact force is converted into a gradual force, so as to avoid overloading damage to the motor, transmission gear and wheel shaft and other key parts.

[0021] 3. The camera and infrared sensor are used together, the four-legged robot collecting system is designed, the four-legged robot obtains more environmental data, and the technical problem that the four-legged robot cannot collect enough environmental data in a complex environment and cannot plan an efficient trajectory is solved. The sensor collected information is combined with the genetic algorithm-roulette in the prior art, the four-legged robot path algorithm is designed, and the problem that the robot is difficult to plan a trajectory in a mountainous area is solved.

[0022] 4. The present application adopts a front elbow and rear knee type leg topology structure, compared with the traditional full elbow type or full knee type, the front elbow and rear knee type adopts a full symmetrical layout technology, which can more effectively suppress the vibration of the body center of gravity and the movement direction caused by joint control failure, and the gap design of the leg structure is reasonable, solving the technical problem that the existing four-legged robot is not flexible due to the too compact leg structure.

[0023] 5. When the four-legged robot needs to stop at a certain position, the turbine output shaft loses driving force, and due to the self-locking force between the turbine output shaft and the worm, the leg structure of the four-legged robot can be in a self-locking state, which is beneficial to the stability of the four-legged robot.

[0024] 6. When the four-legged robot is impacted while crossing the mountains and forests, the robot leg joint is tilted, at this time, the auxiliary righting operation of the robot posture can be realized by adjusting the linear electric cylinder, the running stability and flexible operability of the four-legged robot are improved. In addition, by adjusting the linear electric cylinder, the four-legged robot can be in a special action, such as climbing a slope with many stones, climbing a narrow gap, etc., and the flexibility of the robot is improved.

[0025] 7. Due to the symmetrical structure, when the passive foot segment is under pressure, the pressure is transmitted to the joint bearing support, the joint bearing support drives the sliding rod to slide in the linear bearing, and the sliding rods on both sides drive the sliding blocks to symmetrically slide in the plastic sliding cylinder, so that the spring rod simulates the function of the superficial toe flexor muscle of animals, can realize two-way contraction, makes the leg-foot mechanism have the characteristics of low inertia, at the same time achieves the effects of shock absorption, energy storage and easy to realize obstacle avoidance.

[0026] The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the application will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a front view of the four-legged robot of the present application;

[0028] Figure 2 is a side view of Figure 1 ;

[0029] Figure 3 is a structure schematic diagram of the offset assembly in Figure 2 ;

[0030] Figure 4 is a front view of the hip coaxial gear box;

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

[0032] Figure 6 is a top view of the hip coaxial gear box;

[0033] Figure 7 is a connection structure explosion diagram of the leg structure and the hip coaxial gear box in Figure 1 ;

[0034] Figure 8 is a front view of the leg structure in Figure 1 ;

[0035] Figure 9 is a side view of the leg structure in Figure 1 ;

[0036] Figure 10 is a structure schematic diagram of the spring rod in Figure 1 ;

[0037] Figure 11 is a structure schematic diagram of the first flexible joint;

[0038] Figure 12 is a structure schematic diagram of the second flexible joint. DETAILED DESCRIPTION

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

[0040] Unless otherwise defined, technical terms or scientific terms used in the present application shall have the general meaning understood by a person skilled in the art to which the present application belongs. In the present application, the terms "one", "a", "an", "the", "these", and similar words do not represent a quantitative limitation, but can be singular or plural. In the present application, the terms "include", "contain", "have" and any variants thereof are intended to cover non-exclusive inclusion; for example, a process, method and system, product or device containing a series of steps or modules (units) are not limited to the listed steps or modules (units), but can include steps or modules (units) not listed, or can include other steps or modules (units) inherent to the process, method, product or device. In the present application, the terms "connected", "connected", "coupled" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. In the present application, "multiple" means two or more. The term "and / or" describes the relationship between the associated objects, which means that there can be three relationships, for example, "A and / or B" can mean that A exists alone, A and B exist together, and B exists alone. In general, the character " / " represents an "or" relationship between the associated objects. In the present application, the terms "first", "second", "third" and the like are only used to distinguish similar objects, and do not represent a specific order of the objects.

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

[0042] In the present embodiment, a quadruped robot is provided, please refer to Figure 1 which comprises a shock-absorbing leg structure 2, a main body frame 111 and four hip coaxial gear boxes 6. The present embodiment adopts a front-elbow and rear-knee type leg topology structure. Compared with the traditional full-elbow or full-knee type, the front-elbow and rear-knee type adopts a full-symmetry layout technology, which can more effectively suppress the vibration of the body center of gravity and the movement direction caused by joint control failure. 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 too compact leg structure.

[0043] Please refer to Figure 2The main body frame 111 is a cuboid 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, the main body frame 111 is provided with a binocular camera sensor 1, a scanning radar 3 and a laser radar 5. The camera and infrared sensor are used together to design the collection system of the quadruped robot, so that the quadruped robot obtains more environmental data, and solves the technical problem that the quadruped robot cannot collect enough environmental data in a complex environment and cannot plan an efficient trajectory. The existing technology combines the sensor collected information with the genetic algorithm - roulette, and designs the path algorithm of the quadruped robot, which solves the problem of trajectory planning of the robot in the mountainous area.

[0044] Please refer to Figure 2 and Figure 3 In addition, the four hip coaxial gear boxes 6 are symmetrically and rotatably installed in the inner wall of the main body frame 111, so that Figure 1 For example, two hip coaxial gear boxes 6 are symmetrically and rotatably installed in the left and right inner walls of the main body frame 111, and the two hip coaxial gear boxes 6 located on the front side of the main body frame 111 are also symmetric with the two hip coaxial gear boxes 6 located on the rear side of the main body frame 111. The hip coaxial gear boxes 6 provide four power outputs on the front and rear sides of the main body frame 111, and control the movements of the four legs of the quadruped robot respectively. However, since the hip coaxial gear boxes 6 are rotatably installed in the main body frame 111, the hip coaxial gear boxes 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 boxes 6 are arranged on the inner top of the main body frame 111 to control the offset rotation of the hip coaxial gear boxes 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 installed on the inner top of the main body frame 111. One end of the connecting rod 41 is rotatably installed on the outer wall of the box through the connecting pin 42. The other end of the connecting rod 41 is rotatably connected with the output end of the linear electric cylinder 4. The advantage of this is that the linear electric cylinder 4 controls the rotation offset of the box by controlling the connecting rod 41, thereby controlling the rotation offset of the hip coaxial gear box 6, and controlling the direction and angle change of the leg output end of the hip coaxial gear box 6. When the quadruped robot passes through the mountains and is impacted, the robot leg joint is tilted. At this time, the auxiliary righting operation of the robot posture can be realized by adjusting the linear electric cylinder 4, thereby improving the running stability and flexible operability of the quadruped robot. In addition, by adjusting the linear electric cylinder 4, the quadruped robot can be in special actions, such as climbing a slope with many stones, climbing a narrow gap, etc., thereby improving the flexibility of the robot.

[0045] Please refer to 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 box, a first bevel gear, and a second bevel gear 6.23. The two DC servo motors 6.11 are symmetrically installed in the box, one of which (No. 1 motor) drives the worm 6.6 to rotate, the turbine output shaft 6.22 is rotatably installed inside the box and penetrates the outer wall of the box at one end, the worm 6.6 is in meshing transmission with the turbine on the turbine output shaft 6.22, and the other DC servo motor 6.11 (No. 2 motor) drives the first bevel gear to rotate, where No. 1 and No. 2 are only used to distinguish the DC servo motors 6.11. The helical gear output shaft 6.21 penetrates and is rotatably installed on the outer wall of the box, the helical 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 installed on the outer wall of the helical gear output shaft 6.21, the first bevel gear is in meshing transmission with the second bevel gear 6.23, the joint ring of the first flexible joint 7 is connected with the helical gear output shaft 6.21 through a key, and the power input ring 2.2.2 of the second flexible joint 2.2 is connected with the turbine output shaft 6.22 through 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 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 beneficial to the stable posture of the quadruped robot.

[0046] In practical applications, two DC servo motors 6.11 and worm 6.6 and the first bevel gear are provided with gear boxes 6.7 to match the speed of the rotating shaft, and the output shafts of the two DC servo motors 6.11 are connected with the gear boxes 6.7 through couplings 6.9. A planetary reducer 6.10 is arranged between the DC servo motor 6.11 and the coupling 6.9. Specifically, the hip coaxial gear box 6 is composed of a deep groove ball bearing 6.1, a gear box front end cover 6.2, 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 wheel output shaft 6.22 and a second bevel gear 6.23. The internal driving structure of the hip coaxial gear box 6 is composed of a coupling 6.9, a planetary reducer 6.10, a DC servo motor 6.11, a rear fixed frame 6.12 and a boss 6.13. Angular contact ball bearings are installed in front of and behind the hip coaxial gear box 6, and the installation of the angular contact ball bearings is designed according to the standard of the inner diameter interference fit and the outer diameter clearance fit. The horizontal rolling motion is realized through a linear 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, and in order to overcome the transmission force, the other end of the worm 6.6 is pressed by the deep groove ball bearing 6.16 to ensure that the transmission in both directions has supporting 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 shaft shoulder support and directly outputs power as an 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 outer shaft. According to the stress analysis of the second bevel gear 6.23, it only receives transmission force in one direction in transmission, so it does not need to be supported and pressed on the other end. In order to reduce the transmission gap and improve the transmission efficiency, the hip coaxial gear box 6 adopts one-stage transmission, that is, only one-stage gear transmission. The selected DC servo motor 6.11 is provided with a planetary reducer 6.10, and the reduction ratios are 26 and 156 respectively. 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, further design of the reduction transmission is needed. If ordinary straight or helical teeth are used to realize transmission, the occupied space will be quite large, therefore, the compact worm and gear transmission is considered, and the reduction ratio is selected as 10, which also has the function of reverse self-locking. The motor with a reduction ratio of 156 directly adopts the bevel gear transmission with a transmission ratio of 1 and an angle of 90°.

[0047] Please refer to Figure 7, in general, when the quadruped robot moves, the No. 1 motor drives the worm 6.6 to rotate, 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 with the turbine output shaft 6.22 through 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 shaft connected with the knee joint to rotate, realizing the movement of the knee joint of the quadruped robot. The No. 2 motor drives the first bevel gear to rotate, 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 with the helical gear output shaft 6.21 through 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 with the joint ring to rotate, thereby realizing the control of the movement of the quadruped robot through the driving of the No. 1 motor and the No. 2 motor.

[0048] Please refer to Figures 7 to 12 In the embodiment, a shock-absorbing leg structure 2 of the quadruped robot is further provided, which comprises a thigh rod 2.4, a first flexible joint 7 and a second flexible joint 2.2.

[0049] Please refer to Figure 8 and Figure 11 The thigh rod 2.4 is provided with a mounting hole. The first flexible joint 7 comprises 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 generating excessive impact on the hip coaxial gear box 6. The sealing ring 7.1 is fixedly installed on one side of the outer edge of the mounting hole and coaxially aligned with the mounting hole, the inner wall of the sealing ring 7.1 is protruded to form four uniformly distributed right-angle flanges, the bisector of the right angle of each right-angle flange passes through the center of the sealing ring, the outer wall of the joint ring is protruded to form four uniformly distributed rectangular flanges, and adjacent right-angle flanges and rectangular flanges are connected through a first compression spring 7.2. When impacted, the thigh rod 2.4 will vibrate and deviate, and since the joint ring and the sealing ring 7.1 are connected through 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 of the helical gear output shaft 6.21 connected with the joint ring on the first flexible joint 7, playing a role of relieving the impact force and protecting the movement joint of the robot. At the same time, due to the deformation of the compression spring 7.2, the joint of the leg structure of the robot can be facilitated to restore the movement posture after being impacted, solving the problem that the joint of the leg structure of the robot is difficult to restore the movement posture after being impacted.

[0050] In order to improve the connection strength of the joint ring, further, one blocking block 7.3 is fixed on each side of the rectangular flange and the right angle flange respectively, a gap is left between the adjacent right angle flanges and the two blocking blocks 7.3 of the rectangular flange, and the outer wall of the two blocking blocks 7.3 is sleeved with a first compression spring 7.2, so as to improve the stability of the joint ring during movement.

[0051] In addition, please refer to Figure 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 used for connecting 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 has a through hole formed therein, the through hole is coaxially aligned with the sealing ring 7.1, and the four second compression springs 2.2.3 are located outside the through hole and arranged in a rhombus shape with the heads connected to the tails, the connection points of two opposite second compression springs 2.2.3 are fixed to the outer wall of the power output rod 2.2.1, the outer ring of the power input ring 2.2.2 is protruded to form symmetrical plate-shaped flanges, the plate-shaped flanges are limited to slide in the circumferential direction by the outer wall of the power output rod 2.2.1 through a latch, and the latch passes through the connection points of the other two opposite second compression springs 2.2.3. When impacted, the thigh rod 2.4 will vibrate and deviate, and due to the connection of the plate-shaped flanges of the power input ring 2.2.2 and the second compression springs 2.2.3, when impacted, the vibration and deviation of the second flexible joint 2.2 will be converted into the deformation of the second compression springs 2.2.3 and the rotation of the power input ring 2.2.2, thereby avoiding the direct impact of the power input ring 2.2.2 on the thigh rod 2.4 and playing a protective role on the leg structure. Please refer to Figure 3 Further, the shock-absorbing leg structure further includes a knee joint connecting rod 2.3, a connecting pin 2.5, a lower leg 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 lower leg rod 2.6 is connected to the lower part of the thigh rod 2.4 through a joint bearing, the end of the power output rod 2.2.1 away from the through hole is connected to one side of the top of the lower leg rod 2.6 through the knee joint connecting rod 2.3, the lower part of the lower leg 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 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, 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] Please refer to Figure 8 The thigh rod 2.4, the passive foot segment 2.7, the calf rod 2.6 and the spring rod 2.11 constitute a parallelogram structure, and the four-bar three-segment structure is used to achieve a larger space and simple control principle, and the leg design can ensure the fast running and flexible characteristics of the quadruped robot. The leg configuration adopts the front elbow and rear knee type as the 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 during movement, which significantly weakens the inertial force of the leg movement, so that the robot has good controlled performance, and the use scene is more, which can basically cover most of the above application scenes, especially suitable for rugged road environment.

[0054] The basic principle of the first flexible joint 7 and the second flexible joint 2.2 is that 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 shafts, first transmitted to the input end of the first flexible joint 7 and / or the second flexible joint 2.2 through key connection, and then through the compression or stretching of the compression spring 7.2 and / or the second compression spring 2.2.3, the relatively large impact force is converted into a gradual force, avoiding overloading damage to the motor, transmission gear and wheel shaft and other key parts. The energy accumulated in the compression spring 7.2 and / or the second compression spring 2.2.3 is gradually transmitted to the output end, and then transmitted to the thigh rod by the first flexible joint 7 and / or the knee joint output rod by the second flexible joint 2.2, and then the calf is moved through the connecting rod, thereby realizing the movement of the entire quadruped robot.

[0055] Since the first flexible joint 7 and the second flexible joint 2.2 are subjected to low-frequency vibration during robot movement, the compression spring 7.2 and the second compression spring 2.2.3 can also achieve the effect of effectively reducing vibration and impact without the need for a damper.

[0056] In order to improve the anti-skid performance and action data monitoring ability of the quadruped robot in the mountain forest, further, the shock-absorbing leg structure further includes an anti-skid foot end 2.8, the anti-skid foot end 2.8 is internally provided with a 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 scratch and impact resistance of the leg structure, the shock-absorbing leg structure further comprises a thigh protection cover 2.1 installed on the outer wall of the thigh rod 2.4.

[0058] Please refer to Figure 10 The spring rod 2.11 can adopt the 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 further specially designed. The spring rod 2.11 comprises a plastic sliding cylinder 2.11.8 and a symmetrical telescopic sleeve assembly. The telescopic sleeve assembly comprises 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 support 2.11.1. The spring lower support 2.11.2 and the joint bearing support 2.11.1 are fixedly connected. The linear bearing 2.11.4 is connected with the end of the plastic sliding cylinder 2.11.8 through the fixed support 2.11.5. The compression spring 2.11.3 is sleeved between the linear bearing 2.11.4 and the spring lower support 2.11.2, and the two ends of the compression spring 2.11.3 are fixed with the linear bearing 2.11.4 and the spring lower support 2.11.2 respectively. The spring lower support 2.11.2 is provided with a sliding rod located between the linear bearing 2.11.4 and the spring lower support 2.11.2. The sliding block 2.11.7 is fixed with the sliding rod through the countersunk screw 2.11.6, and the sliding block 2.11.7 is limitedly slid in the inner wall of the plastic sliding 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 support 2.11.1, the joint bearing support 2.11.1 drives the sliding rod to slide in the linear bearing 2.11.4, and the sliding blocks 2.11.7 on both sides are symmetrically slid in the plastic sliding cylinder 2.11.8, so that the spring rod 2.11 simulates the function of the superficial digital flexor muscle of animals, can realize bidirectional contraction, and makes the leg-foot mechanism have the characteristics of low inertia, shock absorption, energy storage and easy obstacle avoidance.

[0059] It should be understood that the specific embodiments described herein are merely for the purpose of explanation and are not intended to limit the application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments provided in the present application without creative labor are within the scope of protection of the present application.

[0060] It is apparent that the drawings depict only some of the embodiments or examples of the application and are therefore not to be considered limiting of the scope of the application, for the application can be applied to other similar situations. Moreover, it is to be understood that unless otherwise specifically stated herein, the application can be practiced with other systems, components, materials and the like without resorting to creativity.

Claims

1. A quadruped robot, characterized in that, include: The shock-absorbing leg structure includes: a thigh rod (2.4), a first flexible joint (7), and a second flexible joint (2.2). The thigh rod (2.4) has mounting holes. The first flexible joint (7) includes a sealing ring (7.1), several first compression springs (7.2), a joint ring, and several blocking blocks (7.3). The sealing ring (7.1) is fixedly installed on one side of the outer edge of the mounting hole and coaxially aligned with the mounting hole. The inner wall of the sealing ring (7.1) protrudes to form four evenly distributed right-angled flanges. The bisector of the right angle of each right-angled flange passes through the center of the sealing ring. The outer wall of the joint ring protrudes to form four evenly distributed rectangular flanges. Adjacent right-angled flanges and rectangular flanges are connected by a first compression spring (7.2). The second flexible joint (2.2) includes a power output rod (2.2.1) and a power input ring (2.2.2). The power input ring (2.2.2) and the joint ring are aligned with the mounting holes 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 has a through hole. The through hole is aligned with the sealing ring (7.1) on the same axis. The four second compression springs (2.2.3) are located on the outer ring of the through hole and are connected end to end in a diamond arrangement. The connection point of two symmetrical second compression springs (2.2.3) is fixed to the outer wall of the power output rod (2.2.1). The outer ring of the power input ring (2.2.2) protrudes to form a symmetrical plate-shaped flange. The plate-shaped flange slides along the circumferential direction with the outer wall of the power output rod (2.2.1) through a pin. The pin passes through the connection points of the other two symmetrical second compression springs (2.2.3). Main framework (111); Four hip coaxial gearboxes (6) are symmetrically and rotatably mounted on the inner wall of the main frame (111). Each hip coaxial gearbox (6) includes two DC servo motors (6.11), a helical gear output shaft (6.21), a worm gear 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 inside the housing. One of the DC servo motors (6.11) drives the worm gear (6.6) to rotate. The worm gear output shaft (6.22) is rotatably mounted inside the housing, with one end of the worm gear output shaft (6.22) penetrating the outer wall of the housing. The worm gear (6.6) and the worm gear output shaft (6.22) are connected. The turbine meshes with the drive, and another DC servo motor (6.11) drives the first bevel gear to rotate. The helical gear output shaft (6.21) passes through and rotates on the outer wall of the housing. The helical 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 installed on the outer wall of the helical gear output shaft (6.21). The first bevel gear and the second bevel gear (6.23) mesh and drive each other. The joint ring of the first flexible joint (7) is connected to the helical gear output shaft (6.21) by a key. 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. In the quadruped robot's movement, one DC servo motor drives the worm gear (6.6) to rotate, which in turn drives the worm wheel to rotate, thereby driving the worm wheel output shaft (6.22) to rotate. The rotation of the worm wheel output shaft (6.22) drives the power input ring (2.2.2) to rotate, thereby driving the shaft connected to the knee joint to rotate, thus realizing the movement of the quadruped robot's knee joint. The other DC servo motor drives the first bevel gear to rotate, which in turn drives the second bevel gear (6.23) to rotate. The rotation of the second bevel gear (6.23) drives 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, thus realizing the control of the quadruped robot's movement.

2. The quadruped robot according to claim 1, characterized in that, The quadruped robot also includes four linear electric cylinder assemblies that are arranged corresponding to the hip coaxial gearbox (6); 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 installed on the inner top of the main frame (111). One end of the connecting rod (41) is rotatably installed on the outer wall of the housing 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).

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

4. The quadruped robot according to claim 1, characterized in that, The main frame (111) is equipped with a scanning radar (3) and a lidar (5).

5. The quadruped robot 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 lower leg rod (2.6), a passive foot segment (2.7), a self-lubricating radial joint bearing (2.9), a connecting shaft (2.10), and a spring rod (2.11). The upper part of the lower leg 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 lower leg rod (2.6) through the knee joint connecting rod (2.3). The lower part of the lower leg 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) protrudes to form a convex plate. The convex plate is rotatably connected to one end of the spring rod (2.11) through the connecting 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).

6. The quadruped robot according to claim 5, characterized in that, The shock-absorbing leg structure also includes an anti-slip foot end (2.8), which has a built-in force sensor and is fixedly installed at the bottom of the passive foot segment (2.7).

7. The quadruped robot according to claim 1, characterized in that, The shock-absorbing leg structure also includes a thigh guard (2.1), which is mounted on the outer wall of the thigh bar (2.4).

8. The quadruped robot according to claim 1, characterized in that, Each rectangular flange and right-angle flange has a blocking block (7.3) fixed on each side. There is a gap between the two blocking blocks (7.3) of the adjacent right-angle flange and rectangular flange, and a first compression spring (7.2) is sleeved on the outer wall of the two blocking blocks (7.3).

9. The quadruped robot according to claim 5, characterized in that, The spring rod (2.11) includes a plastic slide (2.11.8) and symmetrically arranged telescopic components; The telescopic assembly 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 spherical bearing bracket (2.11.1). The lower spring support (2.11.2) and the spherical 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) via the fixed support (2.11.5). The linear bearing (2.11.4) is connected to the spring. A compression spring (2.11.3) is sleeved between the lower support (2.11.2), and the two ends of the compression spring (2.11.3) are fixed to the linear bearing (2.11.4) and the lower support (2.11.2) respectively. A sliding rod is provided on the lower support (2.11.2) and the sliding rod is located between the linear bearing (2.11.4) and the lower 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 the inner wall of the plastic slide cylinder (2.11.8).

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