A hydraulic drive humanoid robot hip

Abstract

This invention relates to a hydraulically driven humanoid robot pelvis, within the field of humanoid robots. It addresses the problems of complex structure and large size in existing hip joint pelvic structures. The pelvic support frame integrates printed hydraulic circuits. A lumbar joint base is mounted on one side of the pelvic support frame along its length. Two hip joint mounts are symmetrically mounted on either side of the pelvic support frame along its width, with the axis of the hip joint mounts aligned with the width of the pelvic support frame. The thickness of the pelvic support frame is less than the outer diameter of the hip joint mounts. A lumbar joint is mounted on the lumbar joint base and drives the pelvic skeleton to achieve posture adjustment. Each hip joint mount contains one hip joint, enabling roll and yaw movements. Each hip joint is connected to a thigh, and the pitch movement of the pelvic skeleton is achieved through the drive of a hydraulic cylinder on the thigh. This invention is applicable to robots that need to carry heavy objects or perform tasks requiring great strength.

Description

Technical Field

[0001] This invention relates to the field of humanoid robot technology, specifically to a hydraulically driven humanoid robot pelvis for use in tasks requiring the carrying of heavy objects or the execution of powerful forces, such as rescue and construction. Background Technology

[0002] Humanoid robots are biomimetic electromechanical automation systems that mimic human structure and behavior in form and function. Their joint movements are similar to humans, possessing excellent mobility and adaptability to complex environments. Currently, humanoid robots primarily use motor-driven systems, but this method suffers from drawbacks such as heavy weight and weak obstacle-crossing ability. The pelvis is a key component of the lower limb movement system in bipedal robots, containing two hip joints that enable four degrees of freedom in the lower limbs, and connecting to the lumbar joints of the upper body.

[0003] In the field of humanoid robots, high-performance actuators should possess characteristics such as a high output force / weight ratio, low output force cost, and high-speed force response, i.e., lightweight, high output force, low energy consumption, and fast response. Existing humanoid robots mostly use motor drives, which are simple in structure, efficient, low in cost, small in space, and have fast control response, making them suitable for long-distance and high-precision control. In this drive method, the motor directly drives the joint rotation through a reducer, or uses an electric cylinder to drive a linkage mechanism to achieve joint rotation. However, this method has high operating requirements, relatively low torque, is prone to stalling, and has low load capacity. For humanoid robots with multiple degrees of freedom, high loads, and high burst / high output, motor drives face the problem of insufficient driving torque.

[0004] In contrast, hydraulic drives typically use hydraulic fluid as the transmission medium, easily converting the rotational motion of a prime mover into linear motion and enabling stepless speed regulation over a wide range during operation. The characteristics of hydraulic systems give them high energy density, a high torque-to-volume ratio, and strong anti-stall capability, allowing them to deliver powerful torque in a lightweight manner. This enables bipedal robots to carry heavy objects or perform tasks requiring significant strength, such as rescue, construction, and military operations. Due to their low inertia, hydraulic systems offer rapid response times.

[0005] For the same size, hydraulic drives significantly outperform all-electric drives in terms of load-bearing capacity. However, hydraulic structures are typically more complex, with more external oil pipes, resulting in greater system weight, and they lack closed-loop servo feedback. Hydraulic components require high manufacturing precision, surface roughness, and stringent material and heat treatment requirements. Maintenance and repair necessitate specialized teams, and operation generates noise. Therefore, despite the many advantages of hydraulic drives, their complexity and high maintenance requirements limit their widespread application.

[0006] The patent application, CN115871019A, entitled "An Integrated Humanoid Parallel Hip and Pelvic Joint Structure," utilizes metal 3D printing technology to integrate and print components such as hydraulic system pipes, reducing the weight and size of existing hydraulically driven humanoid robots to a certain extent. It also enables pelvic pitch, roll, and yaw movements. Achieving these functions requires numerous structural components; for example, roll and yaw movements require multiple components working together, resulting in a complex and redundant structure. Furthermore, even without the hydraulic lines, the external shape of this pelvic structure remains large in both thickness and length, making it unsuitable for performing tasks requiring significant force in confined rescue spaces.

[0007] In summary, the existing hip joint pelvic bone structure suffers from problems of structural complexity and large size. Summary of the Invention

[0008] The purpose of this invention is to solve the problems of complex structure and large size of existing hip joint pelvic bone structures, and to provide a hydraulically driven humanoid robot pelvis.

[0009] The technical solution of this invention is:

[0010] A hydraulically driven humanoid robot pelvis includes a pelvic skeleton, a lumbar joint, and two hip joints. The pelvic skeleton includes a pelvic support frame, a lumbar joint base, and two hip joint mounting frames. Hydraulic circuits are integrated into the pelvic support frame. The lumbar joint base is mounted on one side of the pelvic support frame along its length. The two hip joint mounting frames are symmetrically mounted on both sides of the pelvic support frame along its width, with the axis of the hip joint mounting frames aligned with the width of the pelvic support frame. The thickness of the pelvic support frame is less than the outer diameter of the hip joint mounting frames. The lumbar joints are mounted on the lumbar joint base and drive the pelvic skeleton to achieve posture adjustment. Each hip joint mounting frame houses one hip joint, enabling roll and yaw movements. Each hip joint is connected to a thigh, and the pelvic skeleton's pitch movement is achieved through the drive of a hydraulic cylinder on the thigh.

[0011] Furthermore, the lumbar joint includes a central rotating connector and two side rotating connectors. The central rotating connector is rotatably installed in the middle of the lumbar joint base, and the two side rotating connectors are rotatably installed on the left and right sides of the lumbar joint base, respectively.

[0012] The central rotating connector includes a waist joint connecting shaft, a waist joint bearing, and a waist joint bushing. The waist joint connecting shaft is horizontally inserted into the middle of the waist joint base, and the waist joint bushing is fitted onto the waist joint connecting shaft. A waist joint bearing is installed at each end of the waist joint connecting shaft.

[0013] The rotating connectors on both sides include a waist joint shaft, a waist joint bearing end cap, and a waist joint bearing. The waist joint shaft is horizontally inserted into the inner hole on the left or right side of the waist joint base. A waist joint bearing is fitted at each end of the waist joint shaft, and the outer side of the waist joint bearing is fastened by the waist joint bearing end cap.

[0014] Furthermore, the lumbar joint also includes an IMU sensor, which is installed in the middle of the lumbar joint base.

[0015] Furthermore, each hip joint includes a roll drive assembly and a yaw drive assembly; the roll drive assembly and the yaw drive assembly are mounted on the pelvic support frame and the two hip joint mounts and respectively realize roll motion and yaw motion.

[0016] Furthermore, the roll drive assembly includes a hydraulic cylinder piston assembly, a linear guide, a servo valve, a slider, a slider connecting rod, a hip roll two-force bar, and a roll hydraulic actuator. The roll hydraulic actuator is mounted on the upper part of the pelvic support frame. The hydraulic cylinder piston assembly and the linear guide are horizontally mounted on the pelvic support frame. The roll hydraulic actuator is connected to the hydraulic cylinder piston assembly. The slider is slidably mounted on the linear guide. The piston rod of the hydraulic cylinder piston assembly is connected to the slider. One end of the slider is rotatably connected to the slider connecting rod. The other end of the slider connecting rod is rotatably connected to the hip roll two-force bar rotatably mounted in the hip joint bracket. When the piston rod extends, it drives the slider to move to one side. The slider drives the other end of the slider connecting rod to convert the horizontal linear motion into the rotational motion of the hip roll two-force bar. The servo valve is mounted on the hip joint bracket and controls the movement of the hydraulic cylinder piston assembly.

[0017] Furthermore, the roll drive assembly also includes a hip roll retainer, which is mounted on the outer end of the hip joint mount.

[0018] Furthermore, the yaw drive assembly includes a yaw hydraulic actuator, a hip lateral swing hydraulic cylinder assembly, a hip lateral swing guide rail assembly, and a hip lateral swing two-force bar. The yaw hydraulic actuator is mounted on the upper part of the pelvic support frame. The hip lateral swing hydraulic cylinder assembly is coaxially arranged with the hip joint mounting frame and mounted on the pelvic support frame. The yaw hydraulic actuator is connected to the hip lateral swing hydraulic cylinder assembly. The hip lateral swing guide rail assembly is embedded in and mounted on the inner side wall of the hip joint mounting frame. The piston rod of the hip lateral swing hydraulic cylinder assembly is connected to the slider on the hip lateral swing guide rail assembly. One end of the hip lateral swing two-force bar is connected to the slider, and the other end of the hip lateral swing two-force bar extends outward and protrudes from the hip joint mounting frame. The hip lateral swing two-force bar achieves yaw freedom under the extension and retraction of the hip lateral swing hydraulic cylinder assembly.

[0019] Furthermore, it also includes a hip yaw pin and a thigh connector, with the thigh connector connected to the other end of the hip yaw two-force bar via the hip yaw pin.

[0020] Furthermore, it also includes a hip joint bearing, which rotatably connects the thigh connector to the other end of the hip roll lever.

[0021] Preferably, all machined surfaces on the upper end of the pelvic frame are horizontal planes at the same height.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The pelvic structure of the present invention enables the robot's pelvis to have the characteristics of being compact, highly integrated, lightweight, easy to control, having a large load capacity, and rich sensing information.

[0024] (1) The compact and lightweight pelvic structure is mainly reflected in the fact that the two hip joint mounting brackets 26 of the present invention are in the same width direction as the pelvic protection bracket 24, which avoids the problem of large structural dimensions in the length direction caused by the hip joint mounting bracket 26 extending outward. Moreover, the thickness of the pelvic protection bracket 24 of the present invention is less than the thickness of the hip joint mounting bracket 26, making the pelvic skeleton 19 of the present invention thinner in the thickness direction, thereby making the overall pelvic size more compact.

[0025] (2) High integration: The hip joint and pelvic skeleton and its hydraulic circuits are manufactured using 3D printing technology, with titanium alloy as the high-performance metal. After the integrated printing is completed, the skeleton body is shot-blasted to improve its surface properties, and then precision-machined to complete the processing of various planes and holes, eliminating the need for external oil lines, minimizing space occupation and weight, and providing the possibility for higher motion performance. The hydraulic circuits of the pelvis are integrated with the pelvic skeleton design, integrating the relevant hydraulic circuits of key components such as hydraulic pressure sensors and servo valves, determining the installation positions of relevant parts, simplifying the hydraulic system design, avoiding a messy hydraulic circuit structure, improving the rigidity of the hip joint and pelvic structure, reducing weight, and reducing the size caused by installation space.

[0026] (3) Lightweight is mainly reflected in the fact that the pelvic skeleton design adopts topology optimization for weight reduction and curved surface modeling reconstruction. After topology optimization, the skeleton mass is reduced, the inertia of the hip joint and pelvis is reduced, making the upper and lower limbs easier to control, and making the robot walk, run and jump more flexibly and accurately.

[0027] (4) The simple control is mainly reflected in the fact that the hydraulic cylinder of the hip joint is equipped with an oil pressure sensor and the hydraulic cylinder tail is equipped with a displacement sensor, which can realize control feedback and increase control accuracy.

[0028] (5) Large load capacity is mainly reflected in the fact that it adopts hydraulic drive and is suitable for use in high load environments.

[0029] (6) The rich perception information is mainly reflected in the fact that four hydraulic cylinders drive two hip joints, and the joint angle is calculated by the feedback value of the displacement sensor of the hydraulic rod.

[0030] Therefore, as can be seen from the above analysis, by simulating the multiple degrees of freedom of the human hip joint, this invention ensures structural compactness, high rigidity, and large driving force. This pelvis overcomes the shortcomings of traditional humanoid robot pelvis, such as insufficient degrees of freedom, small motion driving force, and unstable motion. At the same time, it avoids the problems of low rigidity, complex structure, and bulkiness caused by the complex structure of multi-degree-of-freedom humanoid joints.

[0031] 2. This invention relates to an integrated humanoid pelvic structure for use in humanoid bipedal robots. Its structure is simpler: the hip joints are driven by a two-degree-of-freedom series drive, enabling roll and yaw rotation. The leg structure is located on the front of the pelvic skeleton, with two symmetrically distributed hip joints connecting the left and right thighs, totaling four degrees of freedom. The pitch and posterior degrees of freedom of the hip joints are located on the thighs. A lumbar joint base is installed on the upper part of the pelvic skeleton, enabling pelvic posture adjustment and connecting to the upper lumbar joint. During operation, hydraulic oil enters the hydraulic cylinder under the control of a servo valve, pushing the piston rod to move. The piston rod's front end is connected to a slider connector, a pelvic two-force rod, and the hip joints. The hydraulic cylinder piston rod pushes a slider on a linear guide rail, which is connected to the hip joint via a two-force rod. When the yaw hydraulic cylinder pushes the piston rod, the thigh rotates in the yaw direction; when the lateral hydraulic cylinder pushes the piston rod, the thigh rotates in the lateral roll direction. Oil pressure sensors and hydraulic rod displacement sensors at corresponding positions on the hydraulic circuit sense information such as hydraulic cylinder displacement and oil pressure.

[0032] 3. This invention employs an integrated hydraulic drive system, which features a high torque-to-volume ratio and strong anti-stall capability, enabling it to withstand large loads. Through a topology-optimized structural design, the hydraulic circuit and the diaphragm frame are integrated into one unit, effectively overcoming the shortcomings of traditional hydraulic systems such as complex structure, numerous external oil pipes, and heavy weight, thus significantly improving the system's overall integrity and structural airtightness.

[0033] 4. This invention employs a servo valve, an oil pressure sensor, and a displacement sensor, with servo closed-loop control. It can sense the hip joint status in real time and control and adjust the oil pressure and flow rate to achieve precise control, which is convenient and ensures position accuracy.

[0034] 5. This invention uses 3D printing technology for titanium alloy skeletons, which reduces weight while ensuring rigidity, resulting in a small overall structural size and low weight.

[0035] 6. This invention adopts a series mechanism to achieve two degrees of freedom of movement in the left and right hip joints, and the third degree of freedom actuator is set on the thigh, which simplifies the hip joint, makes the thigh movement flexible, stable, simple and reliable, neat in appearance, simple to control, and has the advantages of high rigidity and large load.

[0036] 7. The leg structure is located on the front side of the pelvis, with a simple structure, stable movement, and high control precision. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 yes Figure 1 A partial exploded view in the image; Figure 3 yes Figure 1 The main view; Figure 4 yes Figure 1 Top view; Figure 5 yes Figure 1 Side view; Figure 6 This is a three-dimensional structural diagram of the pelvic skeleton 19; Figure 7 yes Figure 6 The main view; Figure 8 yes Figure 6 Top view; Figure 9 yes Figure 6 Side view.

[0038] The components are: 1. Lumbar joint bearing end cap, 2. Lumbar joint connecting shaft, 3. Lumbar joint shaft, 4. Hydraulic cylinder piston assembly, 5. Linear guide rail, 6. Oil pressure sensor, 7. Servo valve, 8. Lumbar joint bearing, 9. IMU sensor, 10. Hip joint bearing, 12. Lumbar joint bushing, 13. Hip lateral swing guide rail assembly, 14. Hip lateral swing hydraulic cylinder assembly, 15. Hip roll two-force bar, 16. Hip yaw two-force bar, 17. Roll hydraulic actuator, 18. Hip roll retaining ring, 19. Pelvic skeleton, 20. Yaw hydraulic actuator, 21. Hip yaw pin, 23. Lumbar joint base, 24. Pelvic protection frame, 25. Hip joint, 26. Hip joint mounting bracket, 27. Slider, 28. Slider connecting rod. Detailed Implementation

[0039] Specific implementation method one: Combining Figures 1 to 9 This embodiment describes a pelvic frame 19, which also includes a lumbar joint and two hip joints 25. The pelvic frame 19 includes a pelvic support frame 24, a lumbar joint base 23, and two hip joint mounting frames 26. The pelvic support frame 24 has integrated hydraulic circuits. The lumbar joint base 23 is installed on one side of the pelvic support frame 24 along its length. The two hip joint mounting frames 26 are symmetrically installed on both sides of the pelvic support frame 24 along its width, with the axis of the hip joint mounting frames 26 being the same as the width of the pelvic support frame 24. The thickness of the pelvic support frame 24 is less than the outer diameter of the hip joint mounting frames 26. The lumbar joint is installed on the lumbar joint base 23 and drives the pelvic frame 19 to move and adjust its position. Each hip joint mounting frame 26 houses a hip joint 25 and enables rolling and yaw movements. Each hip joint 25 is connected to a thigh, and the pitching movement of the pelvic frame 19 is achieved by driving a hydraulic cylinder on the thigh.

[0040] In this embodiment, the oil circuit and pelvic support frame 24 are integrated into one design, with a total of four hydraulic cylinders driving the two hip joints. The joint angle is calculated from the feedback value of the displacement sensor of the hydraulic rod.

[0041] In this embodiment, the hip joint 25 has two degrees of freedom and is driven by two hydraulic cylinders respectively. The hydraulic cylinders are arranged horizontally back and forth, which can realize yaw and roll movements, and the range of motion angles is relatively large.

[0042] In this embodiment, the hip joint pitch, i.e. the forward and backward swinging degree of freedom of the thigh, is driven by a hydraulic cylinder on the thigh.

[0043] In this embodiment, all sensors and drive controllers in the pelvic structure are integrated on the outside of the pelvic skeleton and communicate via CAN bus, featuring simple power supply and communication interfaces and ease of use.

[0044] The integrated design of the hydraulic circuit and pelvic frame in this embodiment integrates the relevant hydraulic circuits of key components such as hydraulic pressure sensors and servo valves, determines the installation positions of relevant parts, simplifies the hydraulic system design, avoids a messy hydraulic circuit structure, improves the rigidity of the hip joint and pelvic structure, reduces weight, and reduces the size caused by the installation space.

[0045] The pelvic skeleton design employs topology optimization for weight reduction and surface modeling reconstruction. Topology optimization reduces the skeleton's mass, decreases the inertia of the hip joints and pelvis, making the upper and lower limbs easier to control and enabling the robot to walk, run, and jump more flexibly and accurately.

[0046] The pelvic skeleton underwent finite element analysis, which effectively improved its stiffness and stability. Through iterative analysis under stress and design space constraints, the structure of the skeleton's surface model was determined.

[0047] As a preferred option, the hip joint and pelvic skeleton and its hydraulic circuits are manufactured using 3D printing technology, with high-performance titanium alloy as the primary material. After printing, the skeleton body undergoes shot peening to improve surface properties, followed by precision machining to complete the processing of various planes and holes. This eliminates the need for external hydraulic circuits, minimizing space and weight, and enabling higher athletic performance.

[0048] Specific Implementation Method Two: Combining Figures 1 to 6This embodiment describes a lumbar joint comprising a central rotating connector and two side rotating connectors. The central rotating connector is rotatably mounted in the center of the lumbar joint base 23, and the two side rotating connectors are rotatably mounted on the left and right sides of the lumbar joint base 23, respectively. The central rotating connector includes a lumbar joint connecting shaft 2, a lumbar joint bearing 8, and a lumbar joint bushing 12. The lumbar joint connecting shaft 2 is horizontally inserted into the center of the lumbar joint base 23, and the lumbar joint bushing 12 is fitted onto the lumbar joint connecting shaft 2. A lumbar joint bearing 8 is installed at each end of the lumbar joint connecting shaft 2. The two side rotating connectors include a lumbar joint shaft 3, a lumbar joint bearing end cap 1, and a lumbar joint bearing 8. The lumbar joint shaft 3 is horizontally inserted into the inner hole on the left or right side of the lumbar joint base 23, and a lumbar joint bearing 8 is fitted at each end of the lumbar joint shaft 3. The outer surface of the lumbar joint bearing 8 is fastened to the lumbar joint bearing end cap 1.

[0049] This design facilitates connection with the upper body, allowing for flexible adjustments to different postures. Other components and connections are the same as in Specific Implementation Method One.

[0050] Specific implementation method three: Combining Figures 1 to 6 To illustrate this embodiment, the lumbar joint of this embodiment also includes an IMU sensor 9, which is installed in the middle of the lumbar joint base 23.

[0051] This setup facilitates the measurement of data parameters such as the rotational inertia of the lumbar joint. Other components and connections are the same as in specific implementation methods one or two.

[0052] Specific implementation method four: Combination Figures 1 to 6 In this embodiment, each hip joint 25 includes a roll drive assembly and a yaw drive assembly. Both the roll drive assembly and the yaw drive assembly are mounted on the pelvic support frame 24 and the two hip joint mounts 26, respectively realizing roll and yaw movements. This arrangement facilitates the realization of roll and tumble postures. Other components and connections are the same as in any of the first to third embodiments.

[0053] Specific Implementation Method Five: Combining Figures 1 to 6This embodiment describes a roll drive assembly comprising a hydraulic cylinder piston assembly 4, a linear guide rail 5, a servo valve 7, a slider 27, a slider connecting rod 28, a hip roll two-force bar 15, and a roll hydraulic actuator 17. The roll hydraulic actuator 17 is mounted on the upper part of the pelvic support frame 24. The hydraulic cylinder piston assembly 4 and the linear guide rail 5 are horizontally mounted on the pelvic support frame 24. The roll hydraulic actuator 17 is connected to the hydraulic cylinder piston assembly 4. The slider 27 is slidably mounted on the linear guide rail 5. The piston rod of the hydraulic cylinder piston assembly 4 is connected to the slider 27. One end of the slider 27 is rotatably connected to the slider connecting rod 28. The other end of the slider connecting rod 28 is connected to the hip roll two-force bar 15, which is rotatably mounted inside the hip joint mounting frame 26. When the piston rod extends, it drives the slider 27 to move to one side. The slider 27 drives the other end of the slider connecting rod 28 to convert the horizontal linear motion into the rotational motion of the hip roll two-force bar 15. The servo valve 7 is mounted on the hip joint mounting frame 26 and controls the movement of the hydraulic cylinder piston assembly 4.

[0054] This configuration, along with the use of displacement sensors in the roll drive assembly to measure the displacement of the hydraulic rods and calculate the joint rotation angle, eliminates the need for relatively large angle sensors, saving space, improving structural integration, and reducing overall weight. Other components and connections are identical to any one of the specific embodiments one through four.

[0055] This embodiment also includes an oil pressure sensor 6, which is mounted on the pelvic support frame 24 and connected to the hydraulic cylinder piston assembly 4 to facilitate the measurement of the driving oil pressure of the roll hydraulic drive 17.

[0056] In this embodiment, the hip roll lever 15 is a hollow cylindrical structure, which facilitates rotational engagement with the inner wall of the hip joint mounting bracket 26, and also reduces the overall weight of the pelvis.

[0057] In this embodiment, the slider connecting rod 28 is preferably an outwardly protruding arc-shaped connecting rod in actual use. This arc-shaped connecting rod can reduce the space occupied and can also drive the rotational motion of the hip roll two-force bar 15 under the action of the slider. The structure is simpler and the use is more reliable.

[0058] Specific Implementation Method Six: Combination Figures 1 to 6 To illustrate this embodiment, the roll drive assembly of this embodiment also includes a hip roll retainer 18, which is mounted on the outer end of the hip joint mount 26.

[0059] This configuration ensures the safety and stability of the robot during rescue operations. Other components and connections are the same as in any of the five specific implementation methods.

[0060] Specific implementation method seven: Combination Figures 1 to 6 This embodiment describes a yaw drive assembly that includes a yaw hydraulic actuator 20, a hip swing hydraulic cylinder assembly 14, a hip swing guide rail assembly 13, and a hip swing two-force bar 16.

[0061] The yaw hydraulic actuator 20 is installed on the upper part of the pelvic support frame 24. The hip lateral swing hydraulic cylinder assembly 14 is coaxially arranged with the hip joint mounting frame 26 and installed on the pelvic support frame 24. The yaw hydraulic actuator 20 is connected to the hip lateral swing hydraulic cylinder assembly 14. The hip lateral swing guide rail assembly 13 is embedded in and installed on the inner side wall of the hip joint mounting frame 26. The piston rod of the hip lateral swing hydraulic cylinder assembly 14 is connected to the slider on the hip lateral swing guide rail assembly 13. One end of the hip lateral swing two-force rod 16 is connected to the slider. The other end of the hip lateral swing two-force rod 16 extends outward and protrudes from the hip joint mounting frame 26. The hip lateral swing two-force rod 16 realizes the yaw degree of freedom under the extension and retraction of the hip lateral swing hydraulic cylinder assembly 14.

[0062] With this configuration, the hip lateral swing guide rail assembly 13 mainly includes a long strip guide rail and a slider. To save components, the slider can be omitted, and one end of the hip lateral swing two-force rod 16 can be directly slidably connected to the guide rail. The hip lateral swing two-force rod 16 is a long strip rod, and the part extending out of the hip joint mounting bracket 26 is recessed towards the center of the pelvic protection bracket 24. This not only saves space but also avoids interference with the thigh connector. Other components and connections are the same as in any of the specific embodiments one to six.

[0063] Specific implementation method eight: Combination Figures 1 to 6 This embodiment further includes a hip yaw pin 21 and a thigh connector, with the thigh connector and the other end of the hip yaw two-force bar 16 connected by the hip yaw pin 21.

[0064] This configuration connects the roll drive assembly and the yaw drive assembly in series, saving space and preventing interference between them. Other components and connections are the same as in any of the specific embodiments one through seven.

[0065] Specific Implementation Method Nine: Combining Figures 1 to 6 This embodiment further includes a hip joint bearing 10, and the thigh connector and the other end of the hip roll lever 15 are rotatably connected via the hip joint bearing 10. This configuration allows for more flexible movement. Other components and connections are the same as in any of the specific embodiments one to eight.

[0066] Specific Implementation Method Ten: Combining Figures 7 to 9 In this embodiment, all machined surfaces on the upper end of the pelvic frame 19 are horizontal planes at the same height.

[0067] With this configuration, all machined surfaces of the pelvic frame 19 are horizontal and vertical, and all are at the same height, making the structure simple and convenient to manufacture and reducing costs. Other components and connections are the same as in any of the specific embodiments one through nine.

[0068] In this invention, hydraulic pressure sensors are installed on the hydraulic cylinder circuits of the hip joint, and displacement sensors are installed at the tail of the hydraulic cylinder, which can realize control feedback and increase control accuracy.

[0069] Combination Figures 1 to 9 Explanation of the working principle of this invention:

[0070] The integrated humanoid hip joint and pelvic structure of this invention has two symmetrically distributed hip joints and a mounting base for the lumbar joint on the upper part of the pelvis. Each hip joint is driven by two hydraulic cylinders in series. The pelvis is connected to the hip joint, and the hip joint is connected to the thigh. A pitch degree of freedom is set on the thigh, driven by a single hydraulic cylinder. An integrated printed oil circuit is installed on the pelvis, and hydraulic cylinders are installed. The two hydraulic cylinders push the slider on the guide rail through the piston rod, and then push the hip joint through the two-force bar to achieve roll and yaw motion. An oil pressure sensor is installed on the oil circuit, a displacement sensor is installed on the hydraulic rod, and an IMU sensor is installed on the pelvis. The integration of multiple sensors realizes the system's perception and feedback.

[0071] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hydraulically driven humanoid robot pelvis, comprising a pelvic skeleton (19), characterized in that: It also includes a lumbar joint, two hip joints (25), a hip pivot pin (21), a thigh connector, and a hip joint bearing (10). The pelvic frame (19) includes a pelvic support frame (24), a lumbar joint base (23), and two hip joint mounting frames (26). The pelvic support frame (24) is integrated with hydraulic oil circuits. The lumbar joint base (23) is installed on one side of the length direction of the pelvic support frame (24). The two hip joint mounting frames (26) are symmetrically installed on both sides of the width direction of the pelvic support frame (24), and the axis of the hip joint mounting frames (26) is the same as the width direction of the pelvic support frame (24). The thickness of the pelvic support frame (24) is less than the outer diameter of the hip joint mounting frames (26). The lumbar joint is installed on the lumbar joint base (23) and drives the pelvic skeleton (19) to move to achieve posture adjustment; each hip joint mounting bracket (26) has a hip joint (25) installed in it and achieves rolling and yaw movements. Each hip joint (25) is connected to a thigh and the pelvic skeleton (19) is pitched by the hydraulic cylinder on the thigh. Each hip joint (25) includes a roll drive assembly and a yaw drive assembly; the roll drive assembly and the yaw drive assembly are mounted on the pelvic support frame (24) and two hip joint mounts (26) and respectively realize roll motion and yaw motion; The roll drive assembly includes a hydraulic cylinder piston assembly (4), a linear guide (5), a servo valve (7), a slider (27), a slider connecting rod (28), a hip roll two-force bar (15), and a roll hydraulic actuator (17). The hip roll two-force bar (15) is a hollow cylindrical structure that rotates with the inner wall of the hip joint mounting bracket (26). A horizontal rolling hydraulic actuator (17) is installed on the upper part of the pelvic support frame (24). The hydraulic cylinder piston assembly (4) and the linear guide rail (5) are horizontally installed on the pelvic support frame (24). The horizontal rolling hydraulic actuator (17) is connected to the hydraulic cylinder piston assembly (4). The slider (27) is slidably installed on the linear guide rail (5). The piston rod of the hydraulic cylinder piston assembly (4) is connected to the slider (27). The slider (27) is rotatably connected to one end of the slider connecting rod (28). The other end of the slider connecting rod (28) is connected to the hip horizontal rolling two-force bar (15) rotatably installed in the hip joint mounting frame (26). When the piston rod extends, it drives the slider (27) to move to one side. The slider (27) drives the other end of the slider connecting rod (28) to convert the horizontal linear motion into the rotational motion of the hip horizontal rolling two-force bar (15). The servo valve (7) is installed on the hip joint mounting frame (26) and controls the action of the hydraulic cylinder piston assembly (4). The yaw drive assembly includes a yaw hydraulic actuator (20), a hip swing hydraulic cylinder assembly (14), a hip swing guide assembly (13), and a hip swing two-force bar (16). The yaw hydraulic actuator (20) is installed on the upper part of the pelvic support frame (24). The hip lateral swing hydraulic cylinder assembly (14) is coaxially arranged with the hip joint mounting frame (26) and installed on the pelvic support frame (24). The yaw hydraulic actuator (20) is connected to the hip lateral swing hydraulic cylinder assembly (14). The hip lateral swing guide rail assembly (13) is embedded in and installed on the inner side wall of the hip joint mounting frame (26). The piston rod of the hip lateral swing hydraulic cylinder assembly (14) is connected to the slider on the hip lateral swing guide rail assembly (13). One end of the hip lateral swing two-force rod (16) is connected to the slider. The other end of the hip lateral swing two-force rod (16) extends outward and protrudes from the hip joint mounting frame (26). The hip lateral swing two-force rod (16) realizes the yaw degree of freedom under the extension and retraction of the hip lateral swing hydraulic cylinder assembly (14). The thigh connector is connected to the other end of the hip lateral swing two-force bar (16) via a hip lateral swing pin (21); the thigh connector is rotatably connected to the other end of the hip lateral roll two-force bar (15) via a hip joint bearing (10).

2. The hydraulically driven humanoid robot pelvis according to claim 1, characterized in that: The lumbar joint includes a central rotating connector and two side rotating connectors. The central rotating connector is rotatably installed in the middle of the waist joint base (23), and the two rotating connectors are rotatably installed on the left and right sides of the waist joint base (23) respectively. The central rotating connector includes a waist joint connecting shaft (2), a waist joint bearing (8), and a waist joint bushing (12). The waist joint connecting shaft (2) is horizontally inserted into the middle of the waist joint base (23), and the waist joint bushing (12) is fitted on the waist joint connecting shaft (2). A waist joint bearing (8) is installed at each end of the waist joint connecting shaft (2). The rotating connectors on both sides include a waist joint shaft (3), a waist joint bearing end cap (1), and a waist joint bearing (8). The waist joint shaft (3) is horizontally inserted into the inner hole on the left or right side of the waist joint base (23). A waist joint bearing (8) is fitted at each end of the waist joint shaft (3). The outer side of the waist joint bearing (8) is fastened by the waist joint bearing end cap (1).

3. The hydraulically driven humanoid robot pelvis according to claim 2, characterized in that: The lumbar joint also includes an IMU sensor (9), which is installed in the middle of the lumbar joint base (23).

4. The hydraulically driven humanoid robot pelvis according to claim 3, characterized in that: The roll drive assembly also includes a hip roll retainer (18), which is mounted on the outer end of the hip joint mount (26).

5. The hydraulically driven humanoid robot pelvis according to claim 4, characterized in that: The machined surfaces of the upper end of the pelvic skeleton (19) are all horizontal planes at the same height.

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