A hydraulic biped robot with integrated hip joint

Abstract

The invention discloses an integrated hip joint of a hydraulic biped robot, comprising a waist truss, which is a frame structure, and whose internal space is provided with two sets of yaw adjustment mechanisms for respectively controlling the left leg and the right leg of the robot; each set of yaw adjustment mechanisms is connected to the thigh structure of the robot through corresponding roll adjustment mechanisms and pitch adjustment mechanisms in turn; the roll adjustment mechanism comprises a vertically arranged roll hydraulic cylinder, in which a drive block which can move up and down is arranged, and symmetrically arranged through holes are provided at positions corresponding to the drive blocks on the side walls of the roll hydraulic cylinder; the drive blocks are provided with fixed holes, in which a roll transverse axis is installed, the other end of the roll transverse axis extends out of the waist truss, and the other end of the roll transverse axis is rotatably connected to the pitch adjustment mechanism; the invention can reduce the size of the space occupied by the three-degree-of-freedom adjustment mechanism, and reduce the action space required for the three-degree-of-freedom adjustment mechanism when the legs move.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic biped robots, and in particular relates to an integrated hip joint of a hydraulic biped robot. Background Art

[0002] Since the modern era, the research on legged robots has received more and more attention. Compared with wheeled robots, legged robots have four important characteristics. First, the movement of the robot body can be largely independent of the terrain. Within the kinematic constraints of the legs, the legs provide an active suspension system for the body, which to a certain extent realizes the decoupling between the robot body movement and the terrain of the environment. The main suspension of wheeled robots is more restricted by the terrain, thus limiting its activity space and the types of tasks that can be completed. Second, this decoupling allows the robot to actively control the magnitude and direction of the ground contact force to a certain extent, thereby realizing the active control of the center of mass movement and completing a variety of complex limb movements. Third, this decoupling allows a single or multiple legs to temporarily leave contact with the ground, allowing the robot to use discontinuous isolated footholds to avoid obstacles or jump. Fourth, using the end sensors of the legs and feet, the external forces currently exerted on the robot can be fully and effectively perceived, which is convenient for the prediction and control of the body's motion state. These four characteristics enable legged robots to adapt to various rugged terrains and artificial urban environments, truly enter the natural environment and human society, and complete various more complex tasks.

[0003] For legged robots, the importance of hip joints is self-evident. Like humans, the hip joints of bipedal robots need to be able to achieve three degrees of freedom: pitch, roll, and yaw. The importance of high integration in hip joint design is self-evident, which also determines the importance of hip joints. At present, existing bipedal robots all use serial hip joints, which can simply achieve decoupling of three degrees of freedom.

[0004] However, the serial hip joint requires a large space, has a large number of components, and is driven in a linear mode, which results in a large space required for hip joint movement, limiting the miniaturization of hydraulically driven legged robots. Summary of the invention

[0005] The purpose of the present invention is to provide an integrated hip joint for a hydraulic biped robot, which simplifies the structural design and reduces the space occupied by the hip joint and the required movement space.

[0006] The present invention adopts the following technical scheme: an integrated hip joint of a hydraulic bipedal robot, comprising a waist truss, the waist truss being a frame structure, and two sets of yaw adjustment mechanisms for respectively controlling the left leg and the right leg of the robot are installed in its internal space;

[0007] Each set of yaw adjustment mechanisms is connected to the robot's thigh structure through corresponding roll adjustment mechanisms and pitch adjustment mechanisms in turn;

[0008] The roll adjustment mechanism comprises a vertically arranged roll hydraulic cylinder, a drive block which can move up and down is arranged in the roll hydraulic cylinder, and symmetrically arranged through holes are opened at positions corresponding to the drive block on the side wall of the roll hydraulic cylinder;

[0009] The driving block is provided with a fixing hole, a rolling transverse axis is installed in the fixing hole, the other end of the rolling transverse axis extends out of the waist truss, and the other end of the rolling transverse axis is rotatably connected to the pitch adjustment mechanism;

[0010] The rolling hydraulic cylinder is used to drive the driving block to move up and down in its internal space.

[0011] Furthermore, the rolling transverse axis is arranged transversely, and a longitudinal through hole is arranged on it, and a longitudinal fixed axis is passed through the longitudinal through hole.

[0012] Further, both ends of the longitudinal fixed shaft are fixed on the rolling fixed frame;

[0013] The two lateral sides of the rolling fixing frame are open, and the two openings are used for the rolling transverse axis to pass through.

[0014] Furthermore, vertical support rods are provided at the upper and lower ends of the rolling fixing frame;

[0015] The other ends of the two support rods are rotatably connected to the top and bottom ends of the waist truss through yaw bearings respectively.

[0016] Furthermore, a longitudinally arranged connecting rod is provided on one of the two supporting rods, and the other end of the connecting rod is rotatably connected to the yaw hydraulic cylinder. The yaw hydraulic cylinder is transversely arranged, and the other end is rotatably connected to the waist truss.

[0017] Further, the pitch adjustment mechanism comprises two rolling bearings arranged at intervals on the rolling transverse axis, and the two rolling bearings are respectively connected to the left and right sides of the thigh structure through connecting plates;

[0018] The inner side of the thigh structure is provided with a vertical groove, in which a pitch hydraulic cylinder is installed. The pitch hydraulic cylinder is tilted in the front-rear direction of the thigh structure, and a pitch ear plate is fixedly installed at the output end of the pitch hydraulic cylinder. The pitch ear plate is connected to the rolling horizontal axis through a pitch connecting rod.

[0019] Further, the pitch link is rotatably connected to the pitch ear plate;

[0020] The pitch link is rotationally connected to the roll axis.

[0021] Furthermore, rotation angle measuring devices are installed on the rolling transverse axis, the longitudinal fixed axis and the support rod.

[0022] Further, the output ends of the two yaw hydraulic cylinders face oppositely.

[0023] Furthermore, a connecting block is arranged around the outer periphery of the rolling transverse axis and at a position corresponding to the longitudinal through hole.

[0024] The beneficial effects of the present invention are as follows: the present invention can reduce the space occupied by the three-degree-of-freedom adjustment mechanism by placing the yaw adjustment mechanism and the roll adjustment mechanism in the internal space of the waist truss and placing the pitch adjustment mechanism in the thigh structure. By designing the three to be interrelated, the driving axes for the three-degree-of-freedom rotation of the robot's hip joint are combined into one, which greatly reduces the volume required for the hip joint to achieve the same function. At the same time, it reduces the action space required for the three-degree-of-freedom adjustment mechanism during leg movement, simplifies the structural design, and is conducive to the miniaturization of leg-foot robots. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the structure of an integrated hip joint of a hydraulic biped robot according to an embodiment of the present invention;

[0026] Figure 2 It is a schematic diagram of the structure of an embodiment of the present invention when the waist truss is not included;

[0027] Figure 3 It is a schematic diagram of the structure of the roll adjustment mechanism and the yaw adjustment mechanism in an embodiment of the present invention;

[0028] Figure 4 It is a schematic diagram of the structure of the pitch adjustment mechanism and the roll adjustment mechanism in an embodiment of the present invention;

[0029] Figure 5 It is a structural schematic diagram of the roll adjustment mechanism in an embodiment of the present invention;

[0030] Figure 6 Schematic diagram of the structure of the pitch adjustment mechanism in an embodiment of the present invention.

[0031] Among them: 100. Waist truss;

[0032] 200. Pitch adjustment mechanism; 210. Pitch hydraulic cylinder; 220. Pitch ear plate; 230. Pitch connecting rod;

[0033] 300. Roll adjustment mechanism; 310. Roll hydraulic cylinder; 311. Driving block; 320. Roll transverse axis; 321. Connecting block; 330. Roll bearing; 340. Roll fixing frame; 350. Longitudinal fixing axis;

[0034] 400. Yaw adjustment mechanism; 410. Yaw ear plate; 420. Yaw hydraulic cylinder; 430. Connecting rod; 440. Yaw bearing; 450. Support rod. DETAILED DESCRIPTION

[0035] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] The embodiment of the present invention discloses a hydraulic biped robot integrated hip joint, such as Figure 1 As shown, it includes a waist truss 100, which is a frame structure, and its internal space is installed with two sets of yaw adjustment mechanisms 400 for respectively controlling the left leg and the right leg of the robot; each set of yaw adjustment mechanism 400 is connected to the thigh structure of the robot through the corresponding roll adjustment mechanism 300 and pitch adjustment mechanism 200 in turn.

[0037] like Figure 4 As shown, the roll adjustment mechanism 300 includes a vertically arranged roll hydraulic cylinder 310, in which a driving block 311 which can move up and down is arranged, and symmetrically arranged through holes are opened at positions corresponding to the driving block 311 on the side wall of the roll hydraulic cylinder 310; the driving block 311 is opened with a fixing hole, in which a roll horizontal axis 320 is installed, and the other end of the roll horizontal axis 320 extends out of the waist truss 100, and the other end of the roll horizontal axis 320 is rotatably connected to the pitch adjustment mechanism 200; wherein, the roll hydraulic cylinder 310 is used to drive the driving block 311 to move up and down in its internal space.

[0038] The present invention places the yaw adjustment mechanism and the roll adjustment mechanism in the internal space of the waist truss, and places the pitch adjustment mechanism in the thigh structure, thereby reducing the space occupied by the three-degree-of-freedom adjustment mechanism. By designing the three to be interrelated, only the action space required for the three-degree-of-freedom adjustment mechanism during leg movement is reduced, thereby simplifying the structural design and facilitating the miniaturization of the leg-foot robot.

[0039] In addition, compared with the currently disclosed robot designs, the present invention combines the three-degree-of-freedom rotation drive shafts of the robot hip joint into one, which greatly reduces the volume required for the hip joint to achieve the same function. Figure 4 As shown, the support rod 450, the longitudinal fixed axis 350 and the rolling transverse axis 320 are the main rotation axes of the three actions, so that the entire outer frame is an integrated mechanism. Each robot thigh has a separate pitch adjustment mechanism 200, roll adjustment mechanism 300 and yaw adjustment mechanism 400. The three-degree-of-freedom adjustment mechanisms of the two thighs are symmetrically placed and the position design is reasonable, which greatly reduces the space occupancy.

[0040] In the embodiment of the present invention, the yaw adjustment mechanism 400 is used to adjust the offset distance of the thigh structure in the front-to-back direction, the roll adjustment mechanism 300 is used to adjust the deflection distance of the thigh structure in the up-down direction, and the pitch adjustment mechanism 200 is used to adjust the deflection angle of the thigh structure in the front-to-back direction.

[0041] Meanwhile, in the present invention, the lateral direction refers to the left-right direction of the robot, the longitudinal direction refers to the front-back direction of the robot, and the vertical direction refers to the up-down direction of the robot. In addition, the yaw hydraulic cylinder 420, the roll hydraulic cylinder 310, and the pitch hydraulic cylinder 210 in the present invention are all hydraulic cylinders, and the qualifiers "yaw", "roll", and "pitch" are used to indicate their roles in the technical solution, that is, the yaw hydraulic cylinder 420 is a hydraulic cylinder for adjusting the yaw angle, the roll hydraulic cylinder 310 is a hydraulic cylinder for adjusting the roll angle, and the pitch hydraulic cylinder 210 is a hydraulic cylinder for adjusting the pitch angle.

[0042] The oil required for the hydraulic cylinder to move is stored in the oil tank, and the pump provides high-pressure hydraulic oil. In order to stabilize the pressure and take into account the safety of the system, an overflow valve is set at the pump outlet. In the case of short-term high flow, the accumulator is used to replenish the oil to keep the pressure constant. The hydraulic cylinder driving the actuator is controlled by the servo valve for direction and speed. A cooler is set in the hydraulic circuit to keep the working temperature of the oil within a certain range. At the same time, an oil filter is set to keep the hydraulic oil clean.

[0043] In one embodiment, Figure 5 As shown, the rolling horizontal axis 320 is arranged horizontally and has a longitudinal through hole, in which a longitudinal fixed axis 350 is passed, and both ends of the longitudinal fixed axis 350 are fixed on the rolling fixed frame 340; moreover, the two horizontal side surfaces of the rolling fixed frame 340 are open, and the two openings are used for the rolling horizontal axis 320 to pass through.

[0044] By fixing the rolling hydraulic cylinder 310 and the rolling horizontal axis 320, when the driving block 311 in the rolling hydraulic cylinder 310 moves up and down, the rolling horizontal axis 320 can be driven to move up and down. Figure 5 As shown, due to the existence of the longitudinal fixed shaft 350, it serves as the center of the roll transverse axis 320 when rotating, and can drive the pitch adjustment mechanism 200 and the thigh structure to generate a movement distance in the up and down directions, so as to achieve the adjustment of the thigh structure in the roll degree of freedom. As a specific implementation method, a bearing can be installed on the outer periphery of the longitudinal fixed shaft 350, and the bearing can be installed in the longitudinal through hole.

[0045] In addition, in order to increase the strength of the roll transverse axis 320, a connecting block 321 is disposed around the outer periphery of the roll transverse axis 320 and at a position corresponding to the longitudinal through hole. Since the roll transverse axis 320 drives the roll adjustment mechanism 300 and the pitch adjustment mechanism 200 at the same time, and even drives the weight of the entire leg of the robot, the force on the connection is very large. By providing the connecting block 321, the connection between the roll transverse axis 320 and the longitudinal fixed axis 350 can be made stronger, avoiding the roll transverse axis 320 from breaking at this position.

[0046] Specifically, the upper and lower ends of the roll fixing frame 340 are both provided with vertical support rods 450; the other ends of the two support rods 450 are rotatably connected to the top and bottom ends of the waist truss 100 through the yaw bearings 440, respectively. By such a configuration, the roll fixing frame 340 can be driven to rotate in the front-to-back direction by rotating the support rods 450. When it rotates, since there is no relative rotation relationship between the roll transverse axis 320 and the longitudinal fixed axis 350 in this direction, when the roll fixing frame 340 rotates, the roll transverse axis 320 is driven to rotate at the same time, thereby realizing the movement of the thigh structure in the front-to-back direction.

[0047] Regarding the driving problem of yaw angle, such as Figure 3 As shown, in this embodiment, a longitudinally arranged connecting rod 430 is arranged on one of the two supporting rods 450, and the other end of the connecting rod 430 is rotatably connected to the yaw hydraulic cylinder 420, which is arranged transversely and the other end of which is rotatably connected to the waist truss 100. More specifically, the yaw hydraulic cylinder 420 is arranged transversely on the waist truss 100, and the other end of the yaw hydraulic cylinder 420 is connected to the yaw ear plate 410, which is arranged longitudinally and fixedly connected to the waist truss 100.

[0048] As a specific implementation method, both connection ends of the yaw hydraulic cylinder 420 are rotatably connected, which can increase the fault tolerance of the device, protect various components, and increase the protection life.

[0049] In the embodiment of the present invention, Figure 2 As shown, since there are two sets of yaw adjustment mechanisms 400, and both are installed in the inner space of the waist truss 100, in order to save space, the output ends of the two yaw hydraulic cylinders 420 face opposite to each other, and can be connected to the left and right legs respectively.

[0050] In one embodiment, Figure 6 As shown, the pitch adjustment mechanism 200 includes two rolling bearings 330 arranged at intervals on the rolling horizontal axis 320, and the two rolling bearings 330 are respectively connected to the left and right sides of the thigh structure through connecting plates. At the same time, the inner side of the thigh structure has a vertical groove, and a pitch hydraulic cylinder 210 is installed in the groove. The pitch hydraulic cylinder 210 is tilted in the front and rear direction of the thigh structure. The output end of the pitch hydraulic cylinder 210 is fixedly installed with a pitch ear plate 220, and the pitch ear plate 220 is connected to the rolling horizontal axis 320 through a pitch connecting rod 230. By installing the pitch hydraulic cylinder 210 in the vertical groove, it can be integrated into the thigh structure, which saves installation space on the one hand and protects the hydraulic cylinder on the other hand.

[0051] Based on the same principle, the pitch link 230 is rotatably connected to the pitch ear plate 220; the pitch link 230 is rotatably connected to the roll axis 320, so that the thigh structure moves more smoothly.

[0052] In one embodiment, the rolling transverse axis 320, the longitudinal fixed axis 350 and the support rod 450 are all equipped with rotation angle measuring devices, so that the rotation angles in the three degrees of freedom directions can be measured respectively, which is beneficial to the overall control.

[0053] In summary, the requirements of smaller volume and faster control response of the hip joint of the humanoid biped robot are realized. The designed series-parallel hybrid hip joint realizes the parallel control of the yaw degree of freedom and the pitch degree of freedom of the hip joint, as well as the parallel control of the yaw degree of freedom and the pitch degree of freedom.

[0054] The structure of the present invention is particularly suitable for the hip joint of a hydraulically driven humanoid biped robot. The core of the present invention is that the hip joint adopts a rolling hydraulic cylinder 310, which directly reduces the size of the space occupied by the joint compared with the traditional hydraulic cylinder; at the same time, parallel control of two degrees of freedom is realized in the structural design, thereby greatly saving the space occupied by the structure and greatly reducing the delay of the hip joint movement control.

[0055] That is to say, the integrated hydraulically driven humanoid bipedal robot hip joint disclosed in the present invention reduces the size of the space occupied by the joint, and at the same time realizes a series-parallel hybrid design of the three degrees of freedom of the hip joint in the structural design, thereby greatly saving the space occupied by the structure, greatly reducing the delay in the control of the hip joint motion, and realizing a compact and integrated design, which greatly reduces the cumbersomeness of the design of hydraulically driven robot joints in the past, as well as the problem of negative impact on the robot joint movement caused by the excessive mass of the hydraulic drive module during installation.

Claims

1. A hydraulic biped robot integrated hip joint, characterized in that: It comprises a waist truss (100), wherein the waist truss (100) is a frame structure, and two sets of yaw adjustment mechanisms (400) for respectively controlling the left leg and the right leg of the robot are installed in its internal space; Each set of the yaw adjustment mechanisms (400) is connected to the thigh structure of the robot via corresponding roll adjustment mechanisms (300) and pitch adjustment mechanisms (200) in sequence; The roll adjustment mechanism (300) comprises a vertically arranged roll hydraulic cylinder (310), a drive block (311) movable up and down is arranged in the roll hydraulic cylinder (310), and symmetrically arranged through holes are provided at positions on the side wall of the roll hydraulic cylinder (310) corresponding to the drive block (311); The driving block (311) is provided with a fixing hole, a rolling transverse axis (320) is installed in the fixing hole, the other end of the rolling transverse axis (320) extends out of the waist truss (100), and the other end of the rolling transverse axis (320) is rotatably connected to the pitch adjustment mechanism (200); The rolling hydraulic cylinder (310) is used to drive the driving block (311) to move up and down in its internal space; The rolling transverse axis (320) is arranged transversely and is provided with a longitudinal through hole, wherein a longitudinal fixing axis (350) is passed through the longitudinal through hole; Both ends of the longitudinal fixed shaft (350) are fixed on the rolling fixed frame (340); The two transverse side surfaces of the rolling fixing frame (340) are open, and the two openings are used for the rolling transverse axis (320) to pass through; The upper end and the lower end of the rolling fixing frame (340) are both provided with vertical supporting rods (450); The other ends of the two support rods (450) are rotatably connected to the top and bottom ends of the waist truss (100) respectively through yaw bearings (440); A longitudinally arranged connecting rod (430) is provided on one of the two supporting rods (450); the other end of the connecting rod (430) is rotatably connected to a yaw hydraulic cylinder (420); the yaw hydraulic cylinder (420) is transversely arranged and the other end is rotatably connected to the waist truss (100); The pitch adjustment mechanism (200) comprises two rolling bearings (330) arranged at intervals on the rolling transverse axis (320), and the two rolling bearings (330) are respectively connected to the left and right sides of the thigh structure through connecting plates; The inner side of the thigh structure is provided with a vertical groove, a pitch hydraulic cylinder (210) is installed in the groove, the pitch hydraulic cylinder (210) is tilted in the front-rear direction of the thigh structure, a pitch lug plate (220) is fixedly installed at the output end of the pitch hydraulic cylinder (210), and the pitch lug plate (220) is connected to the rolling horizontal axis (320) via a pitch connecting rod (230); The pitch link (230) is rotatably connected to the pitch ear plate (220); The pitch link (230) is rotationally connected to the roll transverse axis (320).

2. The hydraulic biped robot integrated hip joint according to claim 1, characterized in that: The rolling transverse axis (320), the longitudinal fixed axis (350) and the support rod (450) are all equipped with rotation angle measuring devices.

3. The hydraulic biped robot integrated hip joint according to claim 1, characterized in that: The output ends of the two yaw hydraulic cylinders (420) face oppositely.

4. The hydraulic biped robot integrated hip joint according to claim 1, characterized in that: A connecting block (321) is disposed around the outer periphery of the rolling transverse axis (320) and at a position corresponding to the longitudinal through hole.

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