Leg assembly of quadruped robot and quadruped robot

Abstract

The utility model discloses a leg component of a quadruped robot, which belongs to the technical field of robots, solves the problems of poor structural stability and larger rotational inertia of the leg component in the moving process in the prior art, and adopts the technical scheme that the leg component mainly comprises a thigh component and a shank component, the shank assembly comprises a spring, a supporting rod and a sleeve arranged on the supporting rod in a sleeving mode, the supporting rod is in sliding fit with the sleeve, the sleeve is hinged to the thigh assembly, the lower end of the supporting rod is supported on the ground, the spring is arranged on one side of the supporting rod, and the spring is arranged on the other side of the supporting rod. The upper end of the supporting rod extends out of the sleeve and is connected with one end of the spring, the other end of the spring is connected with the sleeve, and the spring stretches out and draws back along with sliding of the supporting rod relative to the sleeve. The leg assembly is used for meeting the requirement for high-speed movement of the quadruped robot, and the utility model further aims to disclose the quadruped robot which adopts the leg assembly in the technical scheme.

Description

Technical Field

[0001] The utility model relates to the technical field of robots, in particular to a leg assembly of a quadruped robot and a quadruped robot. Background Art

[0002] A quadruped robot includes a fuselage and quadruped leg assemblies arranged at the front and rear ends of the fuselage. The leg assembly includes a calf and a thigh. When the quadruped robot is moving, after its leg assembly lands on the ground, an impact force will be generated on the leg assembly by the ground, and the impact force can be transmitted along the leg assembly to the motor. Moreover, the greater the movement speed of the quadruped robot, the greater the impact force. The huge impact force will not only affect the swinging frequency of the motor driving the leg assembly, but also cause damage to the bracket for assembling the motor. Therefore, generally, a quadruped robot can only move at a relatively low speed.

[0003] In order to solve the above problems, some quadruped robots capable of absorbing impact force are disclosed in the prior art, such as the invention patent CN103318289A and the utility model patent CN219544946U. In the prior art, the calf includes two parts, namely a sleeve and a telescopic rod. A compression spring is arranged outside the telescopic rod and / or the sleeve. Under the action of the impact force, the compression spring will contract, thereby reducing the influence of the impact force on the movement of the robot. However, during the telescopic movement of the calf, the dimension of the telescopic rod extending into the sleeve will change, resulting in poor stability of the calf. Moreover, the longer compression spring is prone to instability and bending, and may get stuck in the movement of the sleeve. In addition, the installation position of the compression spring is far from the connection position between the calf and the thigh, and a large moment of inertia will be generated when the leg assembly swings, resulting in a large load on the driving member. Therefore, generally speaking, the leg assembly of the current quadruped robot is not sufficient to support the robot to move at a high speed exceeding 5 m / s. Summary of the Utility Model

[0004] The purpose to be achieved by the utility model is to provide a leg assembly of a quadruped robot, which solves the problems of poor structural stability and large moment of inertia of the leg assembly during the movement in the prior art, so as to meet the requirements of high-speed movement of the quadruped robot.

[0005] To achieve the above purpose, the utility model adopts the following technical scheme: A leg assembly of a quadruped robot includes a thigh assembly and a calf assembly. The calf assembly includes a spring, a support rod, and a sleeve sleeved on the support rod. The support rod is slidably matched with the sleeve. The sleeve is hinged to the thigh assembly. The lower end of the support rod supports on the ground. The spring is arranged on one side of the support rod. The upper end of the support rod extends out of the sleeve and is connected to one end of the spring. The other end of the spring is connected to the sleeve. The spring expands and contracts as the support rod slides relative to the sleeve.

[0006] The telescopic sleeve design adopted in the prior art, such as CN103318289A, has an irreconcilable contradiction, that is, the contradiction between the movement stroke and the connection stiffness. If there are more overlapping areas between the two, the connection strength between the two pipes can be improved, but the movement stroke of the compression spring will decrease accordingly. The robot dynamics simulation test shows that the effective stroke of the spring must meet certain requirements to achieve the need for stable high-speed running. If the length of the leg is increased to increase the length of the spring so that the movement stroke of the spring meets the requirements, there are still constraints between the two performance indicators of the strength and the moment of inertia of the mechanical leg. The increase in leg length leads to a sharp increase in the moment of inertia during swinging, and the parts will undergo significant deformation, affecting the smoothness of its movement. If the material size of the mechanical leg is increased or a stronger material is used, it will lead to an increase in the weight of the leg and further increase the moment of inertia, thereby leading to an increase in the motor load.

[0007] After adopting the technical solution of the present application, the utility model has the following advantages: When the quadruped robot maintains a standing state, the lower end of the support rod supports on the ground, and the upper end of the support rod extends out of the sleeve. When the quadruped robot moves, the support rod can slide relative to the sleeve under the impact force from the ground. During the sliding process, the overlapping area between the support rod and the sleeve remains unchanged, and the connection stiffness will not change with the sliding of the support rod, ensuring the stability of the lower leg assembly during the movement of the quadruped robot.

[0008] The spring is used to extend with the sliding of the support rod after the lower leg assembly is impacted by the ground, so as to convert the impact force into its own elastic deformation to weaken the impact force and reduce the influence of the impact force on the movement of the quadruped robot.

[0009] Since both sides of the sleeve are transparent, the telescopic length of the support rod relative to the sleeve is greatly expanded. Its maximum stroke is only limited by the elastic limit of the tension spring, and the movement stroke of the spring can also meet the requirements. Secondly, one end of the spring is connected to the upper end of the support rod, the other end of the spring is connected to the sleeve, and the spring is arranged on the side of the support rod. The spring expands and contracts with the relative movement between the support rod and the sleeve during the movement of the quadruped robot. The expansion and contraction movement of the spring is located outside the support rod, so the spring will not be stuck between the sleeve and the support rod. In the prior art, since the compression spring needs to be sleeved outside the telescopic rod, the inner diameter of the compression spring needs to be larger than the outer diameter of the telescopic rod, and at the same time the compression spring also needs to have sufficient elastic force, so that the compression spring has a large size and weight. Compared with the prior art, in the present application, because the spring is arranged on the side of the support rod, as long as its elastic performance can meet the use requirements, there is no requirement for its inner diameter. Therefore, the weight of the spring can be reduced, and the installation position of the spring is close to the rotation point of the thigh assembly and the lower leg assembly, minimizing the moment of inertia generated by driving the spring to move. After the moment of inertia of the quadruped robot is reduced, the impact impulse and kinetic energy loss received by the quadruped robot will be reduced accordingly.

[0010] Further, the telescopic direction of the spring is the same as the axial direction of the support rod.

[0011] Adopting the foregoing technical solution, the telescopic direction of the support rod is the same as its own axial direction, and the telescopic direction of the spring is consistent with the telescopic direction of the support rod, so that the spring can better absorb the impact force.

[0012] Further, a first connection end is provided at the upper end of the support rod, a second connection end is provided on the sleeve, and the first connection end and the second connection end are arranged at intervals along the axial direction of the support rod.

[0013] Adopting the foregoing technical solution, the telescopic movement of the spring is a length change in a linear direction. The support rod and the sleeve are in sliding fit. During the relative movement, the relative position in the radial direction between the two will not change. Therefore, there will only be a distance change in the axial direction of the support rod between the first connection end and the second connection end, and both ends of the spring can maintain their positions unchanged, so that the spring can telescopically move along the axial direction of the support rod, thereby making the telescopic direction of the spring consistent with the relative sliding direction of the support rod and the sleeve.

[0014] Further, the first connection end is a first connection column provided on the side of the upper end of the support rod, the second connection end is a second connection column provided on the side wall of the sleeve, one end of the spring is hinged to the first connection column, and the other end of the spring is hinged to the second connection column.

[0015] Adopting the foregoing technical solution, the first connection column protrudes from the side of the support rod, and the second connection column protrudes from the side wall of the sleeve. With such a setting, the spring will not be bent after assembly, and the whole spring is located on the sides of the support rod and the sleeve. When the spring expands and contracts, there will only be friction between the spring and the side wall of the sleeve and the side of the support rod, and the outer peripheral surface of the spring is an arc surface, so even if there is friction, it will not have an obvious impact on the expansion and contraction of the spring. In addition, if the mating parts on the spring, the first connection column and the second connection column are defined, a certain distance can be maintained between the outer periphery of the spring and the support rod and the sleeve, thereby avoiding the generation of friction.

[0016] Further, there are two groups of springs, and the two groups of springs are located on both sides of the support rod and are symmetrically arranged about the axis of the support rod.

[0017] Adopting the foregoing technical solution, the advantages of the symmetrical setting are as follows: 1. If only one side is set, there will be a radial component force when the spring force acts on the support rod. When two sides are set, the component forces can cancel each other out, and the telescopic movement of the support rod relative to the sleeve is smoother; 2. Compared with setting one spring, setting two springs can reduce the size of a single spring, and can also keep the center of gravity of the lower leg assembly on the central axis.

[0018] Furthermore, the surface of the sleeve is inwardly recessed to form an avoidance groove for avoiding the expansion and contraction of the spring, and the avoidance groove is arranged along the axial direction of the support rod.

[0019] By adopting the above-mentioned technical solution, the friction between the spring and the sleeve is reduced or avoided, ensuring that the elastic force of the spring is used for decoupling as much as possible, so as to reduce or eliminate the impact force transmitted to the thigh component.

[0020] Furthermore, a limit piece is provided at the upper end of the support rod for limiting the downward movement of the support rod.

[0021] With the above technical solution, the setting of the limiter can prevent the support rod from collide with the spring and cause the spring to deform after the support rod retracts, and can also prevent the support rod from separating from the sleeve.

[0022] Furthermore, there are at least two support rods, which are arranged in parallel, and the sleeve is provided with through holes having the same number as the support rods, the through holes are spaced apart from each other, and the support rods pass through the through holes respectively.

[0023] The aforementioned technical solution is adopted to set up multiple support rods in order to ensure the strength of the calf assembly. The multiple support rods are spaced apart, and the through holes are also separated and installed separately, which further limits the shaking between the support rods and the sleeve.

[0024] Furthermore, the sleeve is provided with a third connecting end and a fourth connecting end which are arranged at intervals along the axial direction of the support rod, the leg assembly also includes a motor, the thigh assembly includes a shell having a cavity and a connecting rod arranged in the cavity, one end of the connecting rod is hinged to the third connecting end, and the other end of the connecting rod is transmission-connected to the motor to transmit the motor driving force to the calf assembly to drive the calf assembly to swing, and the lower end of the shell is hinged to the fourth connecting end.

[0025] By adopting the above-mentioned technical solution, the motor is directly connected to the connecting rod transmission, which can efficiently transmit the driving force of the motor to the calf assembly, reduce energy loss, and allow the calf assembly to swing over a larger range, thereby improving the flexibility of the robot. The shell, connecting rod, and sleeve form a connecting rod mechanism, and the displacement and posture changes of the output end can be well controlled. It can maintain a high stability during movement, thereby ensuring the high maneuverability of the quadruped robot.

[0026] Another object of the present utility model is to provide a quadruped robot, which adopts the leg assembly in any one of the above technical solutions.

[0027] By adopting the aforementioned technical solutions, since the leg components of any of the aforementioned technical solutions are adopted, the quadruped robot has all the technical effects of the aforementioned technical solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present utility model will be further described below in conjunction with the accompanying drawings:

[0029] Figure 1 It is a schematic diagram of the quadruped robot in the present utility model;

[0030] Figure 2 It is a schematic diagram of another perspective of the quadruped robot in the present utility model;

[0031] Figure 3 It is a schematic diagram of the contact inertia, contact force impulse, and pre - collision speed of a quadruped robot in the prior art when the running speed reaches 8 m / s;

[0032] Figure 4 It is a schematic diagram of the decomposition of the impact speed of a quadruped robot in the prior art when the running speed reaches 8 m / s;

[0033] Figure 5 It is a schematic diagram of the contact inertia, contact force impulse, and pre - collision speed of the quadruped robot in the present utility model when the running speed reaches 8 m / s;

[0034] Figure 6 It is a schematic diagram of the decomposition of the impact speed of the quadruped robot in the present utility model when the running speed reaches 8 m / s;

[0035] Figure 7 It is a schematic diagram of the leg assembly of the quadruped robot in the present utility model;

[0036] Figure 8 It is a schematic diagram of another perspective of the leg assembly of the quadruped robot in the present utility model;

[0037] Figure 9 It is a schematic diagram of yet another perspective of the leg assembly of the quadruped robot in the present utility model;

[0038] Figure 10 It is a cross - sectional view of the leg assembly of the quadruped robot in the present utility model;

[0039] Figure 11 It is an exploded view of the leg assembly of the quadruped robot in the present utility model;

[0040] Figure 12 It is a schematic diagram of the leg assembly of the quadruped robot in the present utility model in another state;

[0041] Figure 13 It is a cross - sectional view of the leg assembly in another state of the leg assembly of the present utility model;

[0042] In the figure, 1 is the front foot; 2 is the rear foot; 10 is the spring; 11 is the support rod; 111 is the first connection end; 112 is the limiting member; 12 is the sleeve; 121 is the second connection end; 122 is the avoidance groove; 123 is the through hole; 124 is the third connection end; 125 is the fourth connection end; 13 is the knee joint; 20 is the housing; 21 is the connecting rod; 30 is the hip joint; 31 is the shoulder joint motor; 32 is the hip joint motor; 33 is the knee joint motor; 34 is the shoulder and hip joint bracket; 35 is the hip and knee joint bracket; 40 is the fuselage. Detailed implementation manners

[0043] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are only some, but not all, of the embodiments of the present utility model.

[0044] The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of the present utility model and the above accompanying drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that such data may be interchanged under appropriate circumstances so that the embodiments of the present utility model described herein can be implemented in an order different from those illustrated or described herein.

[0045] It should be understood that in various embodiments of the present utility model, such as the size of the sequence numbers of each process, it does not mean the sequence of execution. The execution sequence of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present utility model.

[0046] It should be understood that in the present utility model, "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0047] It should be understood that in the present utility model, "a plurality of" means two or more. " / or" is merely a description of the relationship between associated objects, indicating that there can be three relationships. For example, X and / or Y can represent three situations: X exists alone, X and Y exist simultaneously, and Y exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "Including X, Y, and Z" and "including X, Y, Z" mean that X, Y, and Z are all included. "Including X, Y, or Z" means including any one of X, Y, and Z. "Including X, Y, and / or Z" means including any one or any two or all three of X, Y, and Z.

[0048] The technical solution of the present utility model will be described in detail below with specific embodiments. These several specific embodiments can be combined or replaced according to the actual situation, and the same or similar concepts or processes may not be repeated in some embodiments.

[0049] Embodiment 1:

[0050] As Figure 1 and Figure 2 shown, the present utility model provides a leg assembly of a quadruped robot, which is applicable to a quadruped robot. The quadruped robot includes a fuselage 40, a leg assembly, and a driving assembly for driving the movement of the leg assembly. The driving assembly includes a shoulder joint motor 31, a hip joint motor 32, a knee joint motor 33, a shoulder and hip joint bracket 34, and a hip and knee joint bracket 35. The shoulder joint motor 31 is fixedly installed on the fuselage 40, the shoulder and hip joint bracket 34 is fixedly installed on the output shaft of the shoulder joint motor 31, the hip joint motor 32 is fixedly installed on the shoulder and hip joint bracket 34, the hip and knee joint bracket 35 is fixedly installed on the output shaft of the hip joint motor 32, and the knee joint motor 33 is fixedly installed on the hip and knee joint bracket 35.

[0051] In this embodiment, the quadruped robot includes two front feet 1 and two rear feet 2. Two sets of driving mechanisms are provided on each of the front and rear sides of the fuselage 40 to drive the two front feet 1 and the two rear feet 2 respectively. The four sets of driving mechanisms are located on the same horizontal plane, and the two sets of driving mechanisms on the same side of the fuselage 40 are arranged left and right. The quadruped robot controls the actions of the two front feet 1 and the two rear feet 2 through the four sets of driving assemblies respectively, so as to realize the movement or other actions of the quadruped robot.

[0052] The leg assembly is fixedly installed on the knee joint motor 33. Among them, the leg assembly includes a thigh assembly and a calf assembly. The calf assembly is hinged to the thigh assembly, and the hinged position of the calf assembly and the thigh assembly is the hinge point. The thigh assembly is fixed on the knee joint motor 33, and the swing of the thigh assembly in the left-right direction and the front-back direction is realized through the operation of the shoulder joint motor 31 and the hip joint motor 32. The left-right direction and the front-back direction refer to Figure 1 and Figure 2。The calf assembly is drivingly connected to the output shaft of the knee joint motor 33 through a transmission component, and the operation of the knee joint motor 33 drives the calf assembly to swing.

[0053] The calf assembly includes a spring 10, a support rod 11, and a sleeve 12 sleeved on the support rod 11. The support rod 11 is in sliding fit with the sleeve 12. The sleeve 12 is hinged to the thigh assembly. The lower end of the support rod 11 is supported on the ground. The spring 10 is arranged on one side of the support rod 11. The upper end of the support rod 11 extends out of the sleeve 12 and is connected to one end of the spring 10. The other end of the spring 10 is connected to the sleeve 12. The spring 10 expands and contracts as the support rod 11 slides relative to the sleeve 12.

[0054] Compared with the quadruped robot disclosed in the prior art CN103318289A, after adopting the technical solution of the present application, the present utility model has the following advantages: When the quadruped robot maintains a standing state, the lower end of the support rod 11 is supported on the ground, and the upper end of the support rod 11 extends out of the sleeve 12. When the quadruped robot moves, the support rod 11 can slide relative to the sleeve 12 under the impact force from the ground. During the sliding process, the overlapping area between the support rod 11 and the sleeve 12 remains unchanged, and the connection stiffness does not change with the sliding of the support rod 11, ensuring the stability of the calf assembly during the movement of the quadruped robot.

[0055] The spring 10 is used for the calf assembly to elongate as the support rod 11 slides after being impacted by the ground, so as to convert the impact force into its own elastic deformation, thereby weakening the impact force and reducing the influence of the impact force on the movement of the quadruped robot.

[0056] Since both sides of the sleeve 12 are permeable, the telescopic length of the support rod 11 relative to the sleeve 12 is greatly extended, and its maximum stroke is only limited by the elastic limit of the tension spring 10, and the movement stroke of the spring 10 can also meet the requirements. Secondly, one end of the spring 10 is connected to the upper end of the support rod 11, the other end of the spring 10 is connected to the sleeve 12, and the spring 10 is arranged on the side of the support rod 11. The spring 10 expands and contracts with the relative movement of the support rod 11 and the sleeve 12 during the movement of the quadruped robot. The expansion and contraction movement of the spring 10 is located outside the support rod 11. Therefore, the spring 10 will not be stuck between the sleeve 12 and the support rod 11. In the prior art, since the compression spring needs to be sleeved outside the telescopic rod, the inner diameter of the compression spring needs to be greater than the outer diameter of the telescopic rod, and at the same time the compression spring also needs to have sufficient elasticity, so that the compression spring has a large size and weight. Compared with the prior art, in the present application, since the spring 10 is arranged on the side of the support rod 11, as long as its elastic performance can meet the use requirements, there is no requirement for its inner diameter. Therefore, the weight of the spring 10 can be reduced, and the installation position of the spring 10 is close to the rotation point of the thigh component and the calf component, so as to minimize the moment of inertia generated by driving the spring 10 to move. After the moment of inertia of the quadruped robot is reduced, the impact impulse and kinetic energy loss received by the quadruped robot will be reduced accordingly. For a lighter small quadruped robot, the effective stroke of the spring 10 is between 2-5 cm. For a medium-sized quadruped robot, the effective stroke of the spring 10 is between 5-10 cm. For a larger or heavier quadruped robot, the effective stroke of the spring 10 may need to reach 10-20 cm or more.

[0057] Comparing with the quadruped robot without a spring, the leg components of the quadruped robot are rigid legs. Figure 3 and Figure 4 The quadruped robot of is analyzed by a model when its running speed reaches 8 m / s.

[0058] Refer to Figure 3 and Figure 4 , Figure 3 are the contact inertia, contact force impulse and pre-collision speed of the robot when its running speed reaches 8 m / s. Figure 3 In, A is the contact force impulse, v- is the speed of the robot's sole before collision, and Mc is the contact inertia matrix. Figure 4 is the decomposition schematic diagram of the impact speed of the quadruped robot when its running speed reaches 8 m / s.

[0059] The Jacobian matrix components related to the contact leg are: The meaning of each component is the speed of the robot's sole in the world coordinate system under the unit speed of its corresponding generalized coordinate.

[0060] For a robot running at high speed, a significant feature is that the translational speed of the robot in the horizontal direction is greater than the speed in the vertical direction. The speed of the robot in the horizontal direction is close to the reference speed command (the actual speed and the set speed), while the speed in the vertical direction is approximately 0. For a quadruped robot to complete one cycle of motion, that is, for the front legs and hind legs to touch the ground once each, there will be two impact processes, and energy loss will occur during each impact process. Through measurement, when the running speed of the robot reaches 8 m / s, the effect of one cycle is approximately 46 J, and the energy loss generated by a single impact is not less than 21 J. The total energy loss generated by two impacts in one cycle is not less than 42 J, meaning that the kinetic energy loss caused by impacts in the translational direction dominates the kinetic energy loss of all degrees of freedom. To reduce the impact force, the smaller the change in the speed of each generalized coordinate caused by the speed decomposition, the better.

[0061] Through analysis, it can be found that the inertia properties and geometric structure of the robot will affect the impact process. To reduce the impact of the impact process and improve the efficiency of motion, it is necessary to reduce the moment of inertia of the robot and optimize the structure of the robot. After the moment of inertia of the robot is reduced, the impact force impulse and kinetic energy loss received by the robot will be correspondingly reduced. However, in actual situations, the method of reducing mass is not easy to implement, and the potential for improvement is not great. Optimizing the structure is another solution. Since the mechanical leg is light in mass and has a small moment of inertia, the ideal sudden change in impact speed should be achieved through the sudden change in speed of the knee joint 13 and the hip joint 30. However, the actual situation is as Figure 4 shown. Due to and having a very small included angle and being on the same side of v - , this results in a large sudden change in joint angular velocity when decomposing the impact speed based on and two base vectors. In a more extreme case, as the angle of the knee joint 13 decreases, and approach coincidence in direction, which will result in singularity. Therefore, an ideal mechanical leg structure should be able to provide at least one set of orthogonal Jacobian matrix components for the sole, and the generalized coordinates corresponding to this component have a small moment of inertia, so as to achieve the decoupling of the mechanical leg and the torso during the impact process. A mechanical leg with this characteristic can effectively reduce the contact force impulse, and thus reduce the loss during the running process of the robot.

[0062] To achieve the design criterion of impact decoupling between this mechanical leg and the torso, a simple and efficient design solution is to add a series elastic translational degree of freedom to the robot (that is, set the spring 10).

[0063] It should be noted that the knee joint 13 is the hinge point between the thigh component and the calf component. The hip joint 30 is the hinge point between the leg component and the fuselage 40.

[0064] In the solution of this application, the telescopic direction of the spring 10 is the same as the axial direction of the support rod 11. The telescopic direction of the support rod 11 is the same as its own axial direction. The telescopic direction of the spring 10 is consistent with the telescopic direction of the support rod 11, enabling the spring 10 to better absorb the impact force. As Figure 5 and as Figure 6 shown, Figure 5 For a robot using the leg component of this application, the contact inertia, contact force impulse, and pre-collision speed when the running speed reaches 8 m / s are Figure 6 The schematic diagram of the decomposition of the impact speed corresponding to the robot when the running speed reaches 8 m / s.

[0065] Due to the presence of the spring 10, a new set of components is added to the robot contact Jacobian matrix Orthogonal to the components provided by the knee joint This orthogonality between the basis vectors can effectively avoid the singularity of the decomposition of the sudden change speed during the impact process. At the same time, the mass of the spring 10 and the moment of inertia of the knee joint are relatively small. Therefore, when decomposing the impact speed, it is more inclined to decompose in these two degrees of freedom. Combining the two advantages of orthogonality and light inertia, this design of the series spring 10 can achieve the impact decoupling between the mechanical leg and the torso during the impact process, that is, the impact process will not cause a sudden change in the torso speed, thereby improving the movement efficiency of the robot and reducing the impact force pulse. Comparing the contact inertia matrix of the spring-leg robot with that of the rigid-leg robot, the first eigenvalue of the contact inertia matrix of the spring-leg is basically equal to the second eigenvalue of the contact inertia matrix of the rigid-leg, that is, the contact inertia of the spring-leg robot is greatly reduced.

[0066] As Figures 3 to 9 shown, the telescopic movement of the spring 10 is a length change in a linear direction. The support rod 11 and the sleeve 12 are in a sliding fit. During the relative movement, their relative positions in the radial direction will not change. In order to make the telescopic direction of the spring 10 consistent with the relative sliding direction of the support rod 11 and the sleeve 12. The upper end of the support rod 11 is provided with a first connection end 111, and the sleeve 12 is provided with a second connection end 121. The first connection end 111 and the second connection end 121 are arranged at intervals along the axial direction of the support rod 11. Therefore, only the distance change along the axial direction of the support rod 11 exists between the first connection end 111 and the second connection end 121, and both ends of the spring 10 can maintain their positions unchanged, enabling the spring 10 to telescopically move along the axial direction of the support rod 11, so that the telescopic direction of the spring 10 is consistent with the relative sliding direction of the support rod 11 and the sleeve 12.

[0067] Specifically, the first connection end 111 is a first connection post provided on the upper side of the support rod 11, and the first connection post protrudes from the side of the support rod 11. The second connection end 121 is a second connection post provided on the side wall of the sleeve 12, and the second connection post protrudes from the side wall of the sleeve 12. One end of the spring 10 is hinged to the first connection post, and the other end of the spring 10 is hinged to the second connection post. With such a setting, the spring 10 will not be bent after assembly, and the whole spring 10 is located on the sides of the support rod 11 and the sleeve 12. When the spring 10 expands and contracts, there will only be friction between the spring 10 and the side wall of the sleeve 12 and the side of the support rod 11. Moreover, the outer peripheral surface of the spring 10 is an arc surface, so even if there is friction, it will not have an obvious impact on the expansion and contraction of the spring 10. In addition, if the mating parts of the spring 10 with the first connection post and the second connection post are limited, a certain distance can be maintained between the outer periphery of the spring 10 and the support rod 11 and the sleeve 12, thereby further avoiding the generation of friction.

[0068] In the prior art, the spring 10 is arranged on one side of the support rod 11. When the elastic force of the spring 10 acts on the support rod 11, there is a radial component force, which increases the resistance of the support rod 11 to slide relative to the sleeve 12. As Figures 8 to 13 shown, for this reason, in this embodiment, two sets of springs 10 are provided. The two sets of springs 10 are located on both sides of the support rod 11 and are symmetrically arranged about the axis of the support rod 11. The component forces can cancel each other out, and the telescopic movement of the support rod 11 relative to the sleeve 12 is smoother. Compared with setting one spring 10, setting two springs 10 can also reduce the size of a single spring 10 and can also keep the center of gravity of the calf assembly on the central axis.

[0069] Furthermore, a relief groove 122 for the expansion and contraction of the spring 10 is recessed inward on the surface of the sleeve 12, and the relief groove 122 is arranged along the axial direction of the support rod 11. The friction between the spring 10 and the sleeve is reduced or avoided, and the elastic force of the spring 10 is ensured to be used for decoupling as much as possible to reduce or eliminate the impact force transmitted to the thigh assembly.

[0070] In order to prevent the support rod 11 from retracting and hitting the end of the sleeve 12 with the spring 10 and deforming the spring 10, in this embodiment, a limiting member 112 for restricting the downward movement stroke of the support rod 11 is provided at the upper end of the support rod 11. Among them, the first connection post is arranged on the limiting member 112.

[0071] When the quadruped robot moves, the thigh assembly and the driving assembly together drive the calf assembly to swing and complete the ground pushing and landing action. In particular, when the quadruped robot moves at high speed, in order to have a greater driving thrust, the calf assembly swings more. When the quadruped robot is in a high maneuverable state, the angle between the calf assembly and the ground is smaller when the calf assembly pushes the ground or lands. The reaction force of the ground on the calf assembly causes the support rod 11 to bear a larger force component in the radial direction, resulting in easy fracture at the position where the support rod 11 has a weak bearing capacity. Under the same equivalent diameter, multiple support rods 11 have a larger surface area than a single support rod 11. A larger surface area means a larger bearing area. Therefore, by providing at least two parallel support rods 11, the bearing strength of the calf assembly can be effectively improved. Correspondingly, the sleeve 12 is provided with the same number of through holes 123 as the support rod 11. The through holes 123 are separated from each other. The support rods 11 pass through the through holes 123 respectively, so that the support rod 11 can be installed separately, further limiting the shaking between the support rod 11 and the sleeve 12.

[0072] In this embodiment, if Figure 9 As shown, there are three support rods 11, and the sleeve 12 is provided with three through holes 123, and the three support rods 11 are distributed symmetrically in the center. Thus, the stress state between the support rods 11 is balanced as much as possible, and it is avoided that one support rod 11 may need to bear a much larger load than other support rods 11, thereby improving the bearing strength of the support member, and in disguise improving the bearing strength of the weak position on the support rod 11.

[0073] In addition, the thigh component includes a shell 20 with a cavity and a connecting rod 21 arranged in the cavity. In order to realize the connection between the thigh component and the calf component, the sleeve 12 is provided with a third connecting end 124 and a fourth connecting end 125 arranged at intervals along the axial direction of the support rod 11. One end of the connecting rod 21 is hinged to the third connecting end 124, and the other end of the connecting rod 21 is transmission-connected to the knee joint motor 33 to transmit the driving force of the knee joint motor 33 to the calf component to drive the calf component to swing. The lower end of the shell 20 is hinged to the fourth connecting end 125, and the connecting rod 21 and the shell 20 both become transmission components, which can efficiently transmit the driving force of the knee joint motor 33 to the calf component, reduce energy loss, and allow the calf component to swing in a larger range, thereby improving the flexibility of the robot. The shell 20, the connecting rod 21, and the sleeve 12 form a connecting rod 21 mechanism, and the displacement and posture change of its output end can be well controlled, and a high stability can be maintained during the movement, thereby ensuring the high maneuverability of the quadruped robot.

[0074] The utility model also provides a quadruped robot in an embodiment, comprising a leg assembly of any of the above embodiments. The quadruped robot has all the technical effects of the above embodiments and can achieve stable high-speed running.

[0075] When a quadruped robot is running, the front feet 1 and the rear feet 2 alternately support the weight of the quadruped robot and help maintain balance. The calf components will contact the ground and bend relative to the thigh components after being impacted by the ground. When the quadruped robot runs forward, the rear feet 2 are responsible for pushing off the ground to provide the driving force for forward movement, while the front feet 1 provide the necessary friction to maintain balance. The directions of the impact forces from the ground on the calf components of the front feet 1 and the rear feet 2 are opposite. To improve stability, both the front feet 1 and the rear feet 2 are folded inwards. The center of gravity of the robot will be closer to the center position, reducing the center of gravity shift caused by the outward expansion of the leg components, thereby improving the stability of the robot and making the movements of the leg components of the robot more coordinated and reducing the interference between the leg components. This can improve the balance of the robot during dynamic movement.

[0076] It should be noted that, as Figure 1 shown, the front feet 1 are folded inwards towards the rear, and the rear feet 2 are folded inwards towards the front.

[0077] In addition to the above preferred embodiments, the present utility model has other implementation manners. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection claimed by the present utility model.

Claims

1. A leg component of a quadruped robot, comprising a thigh component and a calf component, characterized in that, The calf assembly includes a spring, a support rod, and a sleeve mounted on the support rod. The support rod and the sleeve are slidably matched, and the sleeve is hinged to the thigh assembly. The lower end of the support rod is supported on the ground, and the spring is arranged on one side of the support rod. The upper end of the support rod extends out of the sleeve and is connected to one end of the spring, and the other end of the spring is connected to the sleeve. The spring expands and contracts as the support rod slides relative to the sleeve.

2. The leg assembly of a quadruped robot according to claim 1, characterized in that The expansion and contraction direction of the spring is the same as the axial direction of the support rod.

3. The leg assembly of a quadruped robot according to claim 2, characterized in that, The upper end of the support rod is provided with a first connecting end, and the sleeve is provided with a second connecting end. The first connecting end and the second connecting end are arranged at intervals along the axial direction of the support rod.

4. The leg assembly of a quadruped robot according to claim 3, characterized in that, The first connecting end is a first connecting column arranged on the upper side of the support rod, and the second connecting end is a second connecting column arranged on the side wall of the sleeve. One end of the spring is hinged to the first connecting column, and the other end of the spring is hinged to the second connecting column.

5. The leg assembly of a quadruped robot according to claim 2, wherein, The springs are provided in two groups, and the two groups of springs are located on both sides of the support rod and are symmetrically arranged about the axis of the support rod.

6. The leg assembly of a quadruped robot according to claim 2, wherein, The surface of the sleeve is inwardly recessed to form an escape groove for accommodating the expansion and contraction of the spring, and the escape groove is arranged along the axial direction of the support rod.

7. The leg assembly of a quadruped robot according to claim 1, characterized in that, The upper end of the support rod is provided with a limit piece for limiting the downward movement of the support rod.

8. The leg assembly of a quadruped robot according to claim 1, characterized in that, There are at least two support rods, which are arranged in parallel. The sleeve is provided with through holes which are the same in number as the support rods. The through holes are spaced apart from each other, and the support rods pass through the through holes respectively.

9. The leg assembly of a quadruped robot according to claim 1, characterized in that, The sleeve is provided with a third connecting end and a fourth connecting end which are arranged at intervals along the axial direction of the support rod. The leg assembly also includes a motor. The thigh assembly includes a shell having a cavity and a connecting rod arranged in the cavity. One end of the connecting rod is hinged to the third connecting end, and the other end of the connecting rod is transmission-connected to the motor to transmit the motor driving force to the calf assembly to drive the calf assembly to swing. The lower end of the shell is hinged to the fourth connecting end.

10. A quadruped robot, characterized in that, A leg assembly as claimed in any one of claims 1 to 9 is used.

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