A compact hydraulic drive hip-knee integrated pelvis structure

Abstract

The application relates to a compact hydraulic driving waist-hip integrated pelvis structure, and relates to a pelvis structure. The application is used to solve the problems of complex system structure, large quantity of parts, large weight and numerous oil pipes of the existing hydraulic driving humanoid robot. The waist joint of the application comprises two waist transmission chains, two waist pitching transmission assemblies and a waist rotation driving member, the two waist transmission chains are vertically installed on a pelvis framework, the waist rotation driving member is installed between the two waist pitching transmission assemblies and is in gear engagement with the two waist pitching transmission assemblies; two hip joints are installed on the left and right sides of the pelvis framework; each hip joint comprises a hip yaw transmission chain and a hip roll transmission chain, the hip yaw transmission chain is horizontally installed in the pelvis framework, the hip roll transmission chain is vertically installed in the pelvis framework, and one end of the hip yaw transmission chain and the hip roll transmission chain is connected with a thigh connecting piece. The application is used in a biped robot.

Description

TECHNICAL FIELD

[0001] The present application relates to a pelvis structure, in particular to a compact hydraulic drive hip-waist integrated pelvis structure, especially a multi-degree-of-freedom hydraulic drive integrated human-like pelvis structure for biped robots. BACKGROUND

[0002] The development of humanoid robots is a major challenge in robotics. Humanoid robots generally mimic the structure and function of humans, adopt bipedal motion, and have the ability to move in complex environments. They are widely used in rescue, education, assistance, entertainment and other fields. Biped robots mimic the movement characteristics of humans, and the joints of their lower limbs give them flexible movement functions, including stride, step frequency changes and large maneuvering range. Compared with traditional wheeled or tracked robots, biped robots can better adapt to complex terrain without the need for extensive adaptive modifications to the environment. Biped robots need to achieve breakthroughs in speed, balance coordination, environmental perception, and other aspects, which puts strict requirements on materials, structural design, drivers, control systems, and other aspects. The pelvis is an important part of the lower limb movement system of a biped robot and is one of the key structures of a biped humanoid robot, which connects the upper and lower body structures while achieving a certain degree of freedom.

[0003] Most existing biped robots use motor drives, which have the advantages of simple structure, easy control, and rapid response, but also have certain limitations, especially in complex environments, where it is difficult to provide enough power to cross obstacles. Hydraulic drive has become a promising solution in this context.

[0004] In the field of humanoid robots, it is generally believed that an excellent actuator should have a high output force / weight ratio, a low output force cost, and a high speed of force response. Motor drive, i.e., connecting a motor to a reducer to drive the joint to rotate, or using an electric cylinder to drive a linkage mechanism. Although this driving method occupies a small space, has high precision, and fast control response, its torque output is small, and the load capacity is limited, especially when facing multi-degree-of-freedom large loads, it is easy to appear insufficient driving force. In contrast, hydraulic drive has the advantages of high energy density and high output torque, which can provide powerful driving force in a small size. This makes hydraulic drive very suitable for high-load application scenarios, such as rescue, construction, and other tasks, which match the needs of humanoid robot design. In addition, the high adjustability, precise motion control, and stepless speed regulation characteristics of the hydraulic system allow the biped robot to perform complex actions and maintain balance, especially suitable for irregular terrain and diverse gait requirements.

[0005] However, hydraulic drive also has significant drawbacks, such as complex system structure, large number of parts, heavy weight, and numerous oil pipes, which limit its practical application.

[0006] In summary, the existing hydraulic drive humanoid robot has the problems of complex system structure, large number of parts, heavy weight and numerous oil pipes. SUMMARY

[0007] The present application aims to solve the problems of the existing hydraulic drive humanoid robot, such as complex system structure, large number of parts, heavy weight and numerous oil pipes.

[0008] The technical scheme of the present application is: a compact hydraulic drive waist-hip integrated pelvis structure, comprising a waist joint, a pelvis skeleton and two hip joints, the waist joint comprising two waist transmission chains, two waist pitch transmission assemblies and a waist rotation driving member, the two waist transmission chains being vertically installed on the pelvis skeleton, and the power output sides of the two waist transmission chains extending upward and being connected with one waist pitch transmission assembly respectively, the waist rotation driving member being installed between the two waist pitch transmission assemblies and being in gear engagement with the two waist pitch transmission assemblies; the two hip joints being installed on the left and right sides of the pelvis skeleton, and the output sides of the two hip joints being connected with one thigh connecting member respectively; wherein each hip joint comprises a hip yaw transmission chain and a hip roll transmission chain, the hip yaw transmission chain being horizontally installed in the pelvis skeleton, and the hip roll transmission chain being vertically installed in the pelvis skeleton, and the hip yaw transmission chain and the hip roll transmission chain being connected with one end of the thigh connecting member.

[0009] Further, the waist transmission chain comprises a waist joint two-force rod, a waist hydraulic cylinder, a waist piston assembly, a waist guide rail and a waist sliding block, the waist hydraulic cylinder being integrated on the pelvis skeleton, the waist piston assembly being vertically arranged and connected with the waist hydraulic cylinder, the piston rod of the waist piston assembly being connected with the waist sliding block, the waist guide rail being vertically installed on the pelvis skeleton, and the waist sliding block being slidingly installed on the waist guide rail; one end of the waist joint two-force rod being rotatably installed on the waist joint force receiving end two-force rod connecting shaft of the waist pitch transmission assembly, the other end of the waist joint two-force rod being rotatably connected with the waist sliding block, and the waist sliding block and the waist joint two-force rod moving up and down along the waist guide rail under the action of the waist piston assembly, thereby driving the waist pitch transmission assembly to make pitch movement.

[0010] Further, the waist pitch transmission assembly comprises a gear end cover, a bevel gear, a waist joint force receiving end two-force rod connecting shaft, a gear connecting shaft and an upper journal, the waist joint force receiving end two-force rod connecting shaft and the upper journal being sleeved on the gear connecting shaft, the bevel gear being sleeved on the gear connecting shaft extending out of the upper journal, and the gear end cover being covered on the large end face of the bevel gear.

[0011] Further, the waist rotation driving member comprises a top bevel gear connecting member upper part, a top bevel gear connecting member lower part and an upper rotation bevel gear, the upper rotation bevel gear is rotatably installed in the middle part of the top bevel gear connecting member upper part, the lower part of the top bevel gear connecting member upper part is a left connecting part and a right connecting part, the left connecting part and the right connecting part are respectively installed on the waist joint force end two-force rod connecting shaft of the waist pitch transmission assembly on the corresponding side, and the top bevel gear connecting member lower part is buckled and installed on the waist joint force end two-force rod connecting shaft with the top bevel gear connecting member upper part.

[0012] Preferably, the pelvis framework is made of titanium alloy 3D printing.

[0013] Preferably, one end of the thigh connecting member is provided with a groove D-1.

[0014] Further, the hip yaw transmission chain comprises a yaw hydraulic cylinder, a yaw piston rod, a yaw two-force rod, a yaw linear guide rail and a yaw sliding block, the yaw hydraulic cylinder is installed on the pelvis framework, one end of the yaw piston rod is connected with the yaw hydraulic cylinder, the other end of the yaw piston rod is connected with the yaw sliding block, the yaw sliding block is slidably connected with the yaw linear guide rail installed horizontally on the pelvis framework, one end of the yaw two-force rod is rotatably connected with one end of the thigh connecting member, the other end of the yaw two-force rod is rotatably connected with the yaw sliding block, and the one end of the yaw two-force rod drives the thigh connecting member to perform yaw movement along with the extension and contraction of the yaw piston rod.

[0015] Further, the hip yaw transmission chain comprises an upper bearing seat, a lower bearing seat, a rotating shaft, a hip yaw two-force rod, a hip yaw hydraulic valve, a hip yaw linear guide rail and a hip yaw piston assembly, the rotating shaft is vertically inserted into one end of the thigh connecting member, the upper bearing seat and the lower bearing seat are respectively installed on the upper end and the lower end of the rotating shaft, the upper part of the hip yaw two-force rod is rotatably connected with the upper bearing seat and the lower bearing seat, the lower part of the hip yaw two-force rod is rotatably connected with a yaw sliding block, the yaw sliding block is slidably installed on the hip yaw linear guide rail, the hip yaw piston assembly is connected with the yaw sliding block, and the hip yaw piston assembly drives the hip yaw two-force rod to move up and down through the sliding of the yaw sliding block in the vertical direction in the extension and contraction process, thereby driving the thigh connecting member to realize yaw.

[0016] Preferably, one side of the waist sliding block, the yaw sliding block and the yaw sliding block is a "⊥" shaped sliding block in longitudinal section.

[0017] Preferably, the thigh connecting member is a hollow columnar body structure.

[0018] Compared with the prior art, the present application has the following effects:

[0019] 1、The application introduces the metal 3D printing technology into the hydraulic drive structure. Through the 3D printing technology, the hydraulic oil circuit and the robot skeleton are designed integrally, the complex pipeline and the weight in the traditional hydraulic system are greatly reduced, the compactness and the performance of the system are improved, and the number of parts is reduced. This provides more possibilities for the design of the hydraulic driven biped robot, especially in the application scene of the humanoid robot which needs to realize high output torque in a small volume, the metal 3D printing technology shows significant potential.

[0020] 2、The pelvis of the application comprises two hip joints and one waist joint, providing six degrees of freedom of movement, having the characteristics of compact structure, high integration, light weight, strong load capacity, easy control and rich sensory information. The application reduces the weight of the pelvis structure while improving the torque output capacity of the joint. By reasonably arranging the gravity center and optimizing the joint transmission scheme, the defects of the traditional motor-driven humanoid robot pelvis, such as insufficient degrees of freedom, small driving force and unstable movement, are overcome, and the problems of low stiffness and bulk caused by the complex structure of the multi-degree-of-freedom humanoid joint are avoided. The pelvis has high energy density and strong torque output of the hydraulic drive, and the weight and structural complexity problems in the traditional hydraulic system are solved through the 3D printing technology, providing a new scheme for the design of the pelvis of the humanoid robot.

[0021] 3、The application adopts an integrated hydraulic drive system, mainly referring to the centralized 3D printing and integrated manufacturing of the components of the hydraulic drive, so it has high torque-to-volume ratio and excellent anti-stall capacity, and can withstand large loads. By integrating the oil circuit, hydraulic cylinder and skeleton, the problems of complex structure, redundant oil circuit and excessive weight in the traditional hydraulic system are effectively solved. Not only the additional weight and size caused by the pipeline and other components are reduced, but also the sealing performance and overall reliability of the system are improved. At the same time, the installation space reserved for the pipeline and hydraulic cylinder is saved, making the whole structure more compact and efficient.

[0022] 4、The application also adopts a servo valve, an oil pressure sensor and a displacement sensor, and a higher precision angle encoder is used in the key joint of movement to directly obtain the rotation angle, so that the control is more reliable. The state of each joint is sensed in real time, and the oil pressure and flow are controlled and adjusted to realize precise control, convenient control, ensure position accuracy and realize stepless speed regulation.

[0023] 5、The application adopts titanium alloy 3D printing processing technology based on topology optimization to process the skeleton, and uses the characteristics of 3D printing technology to reduce the weight of non-critical structural parts, so that the overall structure is simple, easy to install and disassemble, and the weight and size are reduced.

[0024] 6、The serial mechanism is adopted, and each two-degree-of-freedom movement of the left and right hip joints (referring to two hip joints C, actually left and right hip joints) is realized, a third-degree-of-freedom driver is arranged on the thigh, the hip joint is simplified, the thigh movement is flexible, the structure is stable, and the advantages of high rigidity and large load are achieved.

[0025] 7、The thigh connecting piece D is arranged, so that the leg structure of the robot can be quickly connected with the pelvic structure of the application, the structure of the connecting position is more stable and simple, installation is convenient, and movement is stable.

[0026] 8、The waist joint A is integrated in the pelvic structure, two degrees of freedom of the waist are realized in the pelvic bone, the overall structure is greatly simplified, and space is saved. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is the overall structure diagram of the application; Figure 2 is the front view of Figure 1 ; Figure 3 is the top view of Figure 1 ; Figure 4 is the side view of Figure 1 ; Figure 5 is the explosion view of the hip joint C; Figure 6 is the explosion view of the waist joint A; Figure 7 is the three-dimensional structure schematic view of the pelvic skeleton B; Figure 8 is the front view of Figure 7 ; Figure 9 is the top view of Figure 7 ; Figure 10 is the side view of Figure 7 .

[0028] In the figure: A, waist joint, A-1, waist joint two-force rod, A-2, waist hydraulic cylinder, A-3, waist piston assembly, A-4, waist guide rail, A-5, waist slider, A-6, gear end cover, A-7, bevel gear, A-8, waist joint force end two-force rod connecting shaft, A-9, gear connecting shaft, A-10, upper shaft, A-11, top bevel gear connecting piece upper part, A-12, top bevel gear connecting piece lower part, A-13, upper rotary bevel gear, B, pelvis framework, C, hip joint, C-1, yaw hydraulic cylinder, C-2, yaw piston rod, C-3, yaw two-force rod, C-4, yaw linear guide rail, C-5, yaw slider, C-6, upper bearing seat, C-7, lower bearing seat, C-8, rotating shaft, C-9, hip lateral swing two-force rod, C-10, hip lateral swing hydraulic valve, C-11, hip lateral swing linear guide rail, C-12, hip lateral swing piston assembly, C-13 oil pressure sensor, D, thigh connecting piece. DETAILED DESCRIPTION

[0029] DETAILED DESCRIPTION Figures 1 to 10 In this embodiment, a compact hydraulic drive waist-hip integrated pelvis structure includes a waist joint A, a pelvis framework B, and two hip joints C. The waist joint A includes two waist transmission chains, two waist pitch transmission assemblies, and a waist rotation driving member. The two waist transmission chains are vertically installed on the pelvis framework B, and the power output sides of the two waist transmission chains extend upward and are connected with one waist pitch transmission assembly respectively. The waist rotation driving member is installed between the two waist pitch transmission assemblies and is in gear meshing with the two waist pitch transmission assemblies. The two hip joints C are installed on the left and right sides of the pelvis framework B, and the output sides of the two hip joints C are connected with one thigh connecting piece D respectively. Each hip joint C includes a hip yaw transmission chain and a hip lateral swing transmission chain. The hip yaw transmission chain is horizontally installed in the pelvis framework B, and the hip lateral swing transmission chain is vertically installed in the pelvis framework B. The hip yaw transmission chain and the hip lateral swing transmission chain are connected with one end of the thigh connecting piece D.

[0030] This embodiment is an integrated human-like pelvis structure applied to a humanoid biped robot, which has six degrees of freedom. The hip joint is a double-degree-of-freedom series drive, which can realize roll (lateral swing) and yaw motion, and the pitch freedom is arranged in the thigh part. Two symmetrical hip joints are connected with left and right thighs respectively, and there are four degrees of freedom in total. In the working process, hydraulic oil flows into the hydraulic cylinder under the control of the servo valve, and the piston rod moves. The piston rod front end is connected with the slider, the two-force rod, and the hip joint, etc., to form a transmission chain of hydraulic cylinder-slider-two-force rod-joint rotation. When the hip yaw hydraulic cylinder acts, the hydraulic cylinder piston rod pushes the slider to move along the linear guide rail, drives the hip joint through the two-force rod, and the thigh realizes the motion in the yaw direction. When the hip lateral swing hydraulic cylinder acts, the thigh swings in the roll direction.

[0031] The two hip joints in the pelvis are each driven by two hydraulic cylinders in series, the two hydraulic cylinders drive the waist joint in parallel, and the hydraulic oil circuit is designed in one with the pelvis framework. The hip lateral swing joint angle is directly measured by an angle encoder, and the rest of the joint angles are calculated from the displacement sensor feedback value of the hydraulic rod.

[0032] The six degrees of freedom of the pelvis in this embodiment are driven by six hydraulic cylinders, which can realize the posture adjustment of hip yaw, hip lateral swing, waist rotation, and waist pitch. It can realize the posture adjustment of the key motion joints of the humanoid robot.

[0033] The hip joint mechanism has two degrees of freedom of lateral swing and yaw, and the hip joint pitch degree of freedom is driven by the hydraulic cylinder on the thigh. Bearings and electrical interfaces are provided on the pelvis hip joint to realize the modular quick connection of the leg structure.

[0034] Specific implementation method two: combined Figures 1 to 4 This embodiment is described, the waist transmission chain of this embodiment includes waist joint two-force rod A-1, waist hydraulic cylinder A-2, waist piston assembly A-3, waist guide rail A-4 and waist sliding block A-5, the waist hydraulic cylinder A-2 is integrated on the pelvis framework B, the waist piston assembly A-3 is vertically arranged and connected with the waist hydraulic cylinder A-2, the piston rod of the waist piston assembly A-3 is connected with the waist sliding block A-5, the waist guide rail A-4 is vertically installed on the pelvis framework B, and the waist sliding block A-5 is slidingly installed on the waist guide rail A-4; One end of the waist joint two-force rod A-1 is rotatably installed on the waist joint force receiving end two-force rod connecting shaft A-8 of the waist pitch transmission assembly, the other end of the waist joint two-force rod A-1 is rotatably connected with the waist sliding block A-5, and the waist sliding block A-5 and the waist joint two-force rod A-1 move up and down along the waist guide rail A-4 under the action of the waist piston assembly A-3, thereby driving the waist pitch transmission assembly to pitch.

[0035] In this way, the waist joint mechanism has two degrees of freedom of rotation and pitch, adopts parallel driving, integrates the spine on the pelvis, simplifies the overall structure and volume, and at the same time outputs larger torque. The other components and connection relationships are the same as those of the specific implementation method one.

[0036] Specific implementation method three: combined Figures 1 to 4In this embodiment, the waist pitch transmission assembly includes a gear end cover A-6, a bevel gear A-7, a waist joint force end two-force rod connecting shaft A-8, a gear connecting shaft A-9, and an upper journal A-10. The waist joint force end two-force rod connecting shaft A-8 and the upper journal A-10 are sleeved on the gear connecting shaft A-9. The bevel gear A-7 is sleeved on the gear connecting shaft A-9 extending out of the upper journal A-10. The gear end cover A-6 is covered on the large end surface of the bevel gear A-7. In this way, the waist joint is also integrated in the pelvis structure, providing two degrees of freedom of waist rotation and waist pitch. The parallel driving mode is adopted, and the waist joint is driven by two parallel hydraulic cylinders. When the two hydraulic cylinders act in the same direction, the upper body of the robot realizes the pitch motion. When the two hydraulic cylinders act in opposite directions, the upper body of the robot realizes the rotation motion. In the driving process, the waist joint force end two-force rod connecting shaft A-8 drives the bevel gear A-7 to rotate. In addition, displacement and oil pressure information are detected and fed back through an oil pressure sensor and a hydraulic rod displacement sensor. The other components and connection relationships are the same as those in the first or second embodiment.

[0037] Specific embodiment four: combination Figures 1 to 4 In this embodiment, the waist pitch transmission assembly includes a gear end cover A-6, a bevel gear A-7, a waist joint force end two-force rod connecting shaft A-8, a gear connecting shaft A-9, and an upper journal A-10. The waist joint force end two-force rod connecting shaft A-8 and the upper journal A-10 are sleeved on the gear connecting shaft A-9. The bevel gear A-7 is sleeved on the gear connecting shaft A-9 extending out of the upper journal A-10. The gear end cover A-6 is covered on the large end surface of the bevel gear A-7. In this way, the waist joint is also integrated in the pelvis structure, providing two degrees of freedom of waist rotation and waist pitch. The parallel driving mode is adopted, and the waist joint is driven by two parallel hydraulic cylinders. When the two hydraulic cylinders act in the same direction, the upper body of the robot realizes the pitch motion. When the two hydraulic cylinders act in opposite directions, the upper body of the robot realizes the rotation motion. In the driving process, the waist joint force end two-force rod connecting shaft A-8 drives the bevel gear A-7 to rotate. In addition, displacement and oil pressure information are detected and fed back through an oil pressure sensor and a hydraulic rod displacement sensor. The other components and connection relationships are the same as those in the first or second embodiment.

[0038] Specific embodiment five: combination Figures 7 to 10 In this embodiment, the pelvis framework B is made of titanium alloy 3D printing. In this way, the joints, the pelvis framework, and the hydraulic oil circuit are manufactured using 3D printing technology, and titanium alloy high-performance metal is selected to reduce weight while improving stiffness. After printing, the surface performance of the framework is improved through the shot peening process, and various planes and holes are processed. The other components and connection relationships are the same as those in the first, second, third, or fourth embodiment.

[0039] The pelvis skeleton framework of the embodiment is subjected to finite element analysis, effectively improving the rigidity and stability of the framework. During the entire optimization design process, the finite element analysis plays a role of constraint feedback, and through continuous iteration under the constraint conditions of stress and design space, the structure of the framework surface model is finally determined.

[0040] The pelvis skeleton framework is designed to reduce weight and connection by topology optimization. Topology optimization design can obtain the minimum mass on the basis of ensuring the structural strength, so that the topology optimization design reduces the inertia of the hip joint and the pelvis, making it easier to control the upper and lower limbs, and the biped robot is more flexible, accurate and fast in walking, running and jumping.

[0041] The pelvis skeleton framework adopts an angle encoder with relatively high precision at the hip side swing joint which is a key motion joint with high required precision and large error accumulation, further improving the motion precision and simplifying the control.

[0042] The pelvis skeleton framework adopts a displacement sensor to measure the displacement of the hydraulic rod, so as to calculate the rotation angle of the joint, save space, improve the integration of the structure, and reduce the overall weight.

[0043] The processing surfaces of the pelvis skeleton framework of the embodiment are all horizontal and vertical processing surfaces with consistent height, and the structure is simple and convenient to process, reducing the cost.

[0044] The pelvis sensor, driver and controller are all arranged on the outside of the pelvis skeleton framework, which is convenient to install. The electrical elements communicate through CAN bus, which has the characteristics of simple power supply and communication interface and convenient use.

[0045] Specific implementation method six: combination Figures 1 to 4 In this embodiment, one end of the thigh connecting piece D is provided with a groove D-1.

[0046] In this way, the weight is reduced, and the installation space for fixing the yaw second force rod C-3 of the hip yaw transmission chain is provided, and the yaw is smooth. The other components and connection relationships are the same as those of the first, second, third, fourth or fifth specific embodiments.

[0047] Specific implementation method seven: combination Figure 1 、 Figure 2 、 Figure 3 and Figure 5The hip yaw transmission chain of the embodiment comprises a yaw hydraulic cylinder C-1, a yaw piston rod C-2, a yaw two-force lever C-3, a yaw linear guide C-4 and a yaw slider C-5. The yaw hydraulic cylinder C-1 is installed on the pelvis framework B. One end of the yaw piston rod C-2 is connected with the yaw hydraulic cylinder C-1, and the other end of the yaw piston rod C-2 is connected with the yaw slider C-5. The yaw slider C-5 is slidingly connected with the yaw linear guide C-4 which is horizontally installed on the pelvis framework B. One end of the yaw two-force lever C-3 is rotatably connected with one end of the thigh connecting piece D, and the other end of the yaw two-force lever C-3 is rotatably connected with the yaw slider C-5. The one end of the yaw two-force lever C-3 drives the thigh connecting piece D to yaw with the extension and retraction of the yaw piston rod C-2.

[0048] Thus, the yaw piston rod C-2 extends and retracts under the drive of the yaw hydraulic cylinder C-1. When the yaw piston rod C-2 extends, the yaw slider C-5 slides on the yaw linear guide C-4, and the yaw two-force lever C-3 on the yaw slider C-5 drives the thigh connecting piece D to yaw.

[0049] Specific embodiment eight: Figure 1 , Figure 2 , Figure 3 and Figure 5 The hip yaw transmission chain of the embodiment comprises an upper bearing seat C-6, a lower bearing seat C-7, a rotating shaft C-8, a hip yaw two-force lever C-9, a hip yaw hydraulic valve C-10, a hip yaw linear guide C-11 and a hip yaw piston assembly C-12.

[0050] The rotating shaft C-8 is vertically inserted into one end of the thigh connecting piece D. The upper bearing seat C-6 and the lower bearing seat C-7 are respectively installed on the upper end and the lower end of the rotating shaft C-8. The upper part of the hip yaw two-force lever C-9 is rotatably connected with the upper bearing seat C-6 and the lower bearing seat C-7. The lower part of the hip yaw two-force lever C-9 is rotatably connected with a yaw slider. The yaw slider is slidingly installed on the hip yaw linear guide C-11. The hip yaw piston assembly C-12 is connected with the yaw slider. During the extension and retraction of the hip yaw piston assembly C-12, the yaw slider slides in the vertical direction to drive the hip yaw two-force lever C-9 to move up and down, thereby driving the thigh connecting piece D to yaw.

[0051] In this way, the side swing and yaw movement of the thigh connecting piece D are both applied to one end of the thigh connecting piece D, and the two movements do not interfere with each other, the hip side swing transmission chain mainly acts on the thigh connecting piece D in the vertical direction, and the hip yaw transmission chain acts on the thigh connecting piece D in the horizontal direction, so that the switching of the two degrees of freedom of the hip joint is smooth and stable. The other components and connection relationships are the same as any one of embodiments 1 to 7.

[0052] Embodiment nine: Figure 5 In this embodiment, the waist slider A-5, the yaw slider C-5 and the side swing slider of the embodiment are in the shape of a "⊥" shaped slider. In this way, when connected with the hip side swing two-force rod C-9, a pin shaft can be inserted in the middle, and the other side of the slider is a long strip-shaped block, which is convenient for connecting with the end of the piston rod. The other components and connection relationships are the same as any one of embodiments 1 to 8.

[0053] Embodiment ten: Figures 1 to 4 In this embodiment, the thigh connecting piece D is in a hollow columnar body structure. In this way, the weight is reduced, and the connection and positioning with the thigh are facilitated. The other components and connection relationships are the same as any one of embodiments 1 to 8.

[0054] Embodiment eleven: Figures 1 to 10 The working principle of the present application is explained as follows:

[0055] The integrated human-like parallel hip joint pelvic structure of the present application comprises two hip joints symmetrically distributed on the left and right and a waist joint located in the middle of the pelvis. Each hip joint is operated by two series-connected hydraulic cylinders, the pelvis connects the hip joints, and the hip joints connect the thighs. A hip joint pitch degree of freedom is provided on the thigh and is driven by a single hydraulic cylinder. The two degrees of freedom of the waist joint are controlled by two parallel hydraulic cylinders. The entire structure adopts integrated 3D printing technology, and the oil circuit and hydraulic cylinders are integrated inside the pelvis, and precise components such as hydraulic valves and oil pressure sensors are independently installed. The hydraulic cylinders drive the sliders to move along the guide rails through the piston rods, and then drive the joints through the two-force rods to realize rotary motion. An oil pressure sensor is installed on the oil circuit, a displacement sensor is installed on the hydraulic rod, an IMU sensor is installed at the center of the pelvis for attitude measurement, and an angle encoder is installed at the hip side swing joint. The integration of multiple sensors realizes precise measurement and feedback of the system, and improves the overall control accuracy.

[0056] Although the present application has been disclosed with reference to the preferred embodiments above, it is not intended to limit the present application, and those skilled in the art can make other changes within the spirit of the present application and apply the present application to fields not mentioned in the present application. Of course, these changes made in the spirit of the present application should be included in the scope of protection claimed by the present application.

Claims

1. A compact hydraulically driven integrated lumbar and hip pelvic structure, characterized in that: It includes the lumbar joint (A), the pelvic skeleton (B), and two hip joints (C). The lumbar joint (A) includes two lumbar drive chains, two lumbar pitch drive components and a lumbar rotation drive component. The two lumbar drive chains are vertically mounted on the pelvic frame (B), and the power output side of the two lumbar drive chains extends upward and is connected to a lumbar pitch drive component respectively. The lumbar rotation drive component is mounted between the two lumbar pitch drive components and meshes with the gear between the two lumbar pitch drive components. Two hip joints (C) are installed on the left and right sides of the pelvic frame (B), and the output side of each hip joint (C) is connected to a thigh connector (D); wherein, each hip joint (C) includes a hip yaw drive chain and a hip lateral swing drive chain, the hip yaw drive chain is installed horizontally in the pelvic frame (B), the hip lateral swing drive chain is installed vertically in the pelvic frame (B), and both the hip yaw drive chain and the hip lateral swing drive chain are connected to one end of the thigh connector (D); The waist pitch transmission assembly includes a gear end cap (A-6), a bevel gear (A-7), a two-force member connecting shaft at the waist joint bearing end (A-8), a gear connecting shaft (A-9), and an upper spindle (A-10). The two-force member connecting shaft (A-8) and the upper spindle (A-10) at the waist joint bearing end are mounted on the gear connecting shaft (A-9). The bevel gear (A-7) is mounted on the gear connecting shaft (A-9) which extends outward from the upper spindle (A-10). The gear end cap (A-6) is mounted on the large end face of the bevel gear (A-7). The waist rotation drive includes an upper part (A-11) of the top bevel gear connector, a lower part (A-12) of the top bevel gear connector, and an upper rotating bevel gear (A-13). The upper rotating bevel gear (A-13) is rotatably mounted in the middle of the upper part (A-11) of the top bevel gear connector. The lower part of the upper part (A-11) of the top bevel gear connector is divided into a left connecting part and a right connecting part. The left connecting part and the right connecting part are respectively mounted on the waist joint force-bearing end two-force rod connecting shaft (A-8) on the waist pitch transmission assembly on the corresponding side. The lower part (A-12) of the top bevel gear connector is fastened to the upper part (A-11) of the top bevel gear connector and mounted on the waist joint force-bearing end two-force rod connecting shaft (A-8).

2. The compact hydraulically driven integrated lumbar and hip pelvic structure according to claim 1, characterized in that: The lumbar drivetrain includes a lumbar joint two-force bar (A-1), a lumbar hydraulic cylinder (A-2), a lumbar piston assembly (A-3), a lumbar guide rail (A-4), and a lumbar slider (A-5). The lumbar hydraulic cylinder (A-2) is integrated on the pelvic frame (B). The lumbar piston assembly (A-3) is vertically arranged and connected to the lumbar hydraulic cylinder (A-2). The piston rod of the lumbar piston assembly (A-3) is connected to the lumbar slider (A-5). The lumbar guide rail (A-4) is vertically mounted on the pelvic frame (B). The lumbar slider... (A-5) is slidably mounted on the waist guide rail (A-4); one end of the waist joint two-force bar (A-1) is rotatably mounted on the waist joint force-bearing end two-force bar connecting shaft (A-8) of the waist pitch transmission assembly, and the other end of the waist joint two-force bar (A-1) is rotatably connected to the waist slider (A-5). Under the action of the waist piston assembly (A-3), the waist slider (A-5) and the waist joint two-force bar (A-1) move up and down along the waist guide rail (A-4), thereby driving the waist pitch transmission assembly to perform pitch motion.

3. The compact hydraulically driven integrated lumbar and hip pelvic structure according to claim 2, characterized in that: The pelvic skeleton (B) is made of titanium alloy by 3D printing.

4. A compact hydraulically driven integrated lumbar and hip pelvic structure according to claim 3, characterized in that: A groove (D-1) is provided at one end of the thigh connector (D).

5. A compact hydraulically driven integrated lumbar and hip pelvic structure according to claim 4, characterized in that: The hip yaw drivetrain includes a yaw hydraulic cylinder (C-1), a yaw piston rod (C-2), a yaw two-force bar (C-3), a yaw linear guide (C-4), and a yaw slider (C-5). The yaw hydraulic cylinder (C-1) is mounted on the pelvic frame (B). One end of the yaw piston rod (C-2) is connected to the yaw hydraulic cylinder (C-1), and the other end of the yaw piston rod (C-2) is connected to the yaw slider (C-5). The yaw slider (C-5) is slidably connected to the yaw linear guide rail (C-4) horizontally mounted on the pelvic frame (B). One end of the yaw two-force rod (C-3) is rotatably connected to one end of the thigh connector (D), and the other end of the yaw two-force rod (C-3) is rotatably connected to the yaw slider (C-5). The yaw two-force rod (C-3) drives the thigh connector (D) to yaw as the yaw piston rod (C-2) extends and retracts.

6. A compact hydraulically driven integrated lumbar and hip pelvic structure according to claim 5, characterized in that: The hip lateral swing transmission chain includes an upper bearing housing (C-6), a lower bearing housing (C-7), a rotating shaft (C-8), a hip lateral swing two-force bar (C-9), a hip lateral swing hydraulic valve (C-10), a hip lateral swing linear guide (C-11), and a hip lateral swing piston assembly (C-12). The pivot (C-8) is vertically inserted into one end of the thigh connector (D). The upper bearing seat (C-6) and the lower bearing seat (C-7) are respectively installed on the upper and lower ends of the pivot (C-8). The upper part of the hip lateral swing two-force bar (C-9) is rotatably connected to the upper bearing seat (C-6) and the lower bearing seat (C-7). The lower part of the hip lateral swing two-force bar (C-9) is rotatably connected to the lateral swing slider. The lateral swing slider is slidably installed on the hip lateral swing linear guide rail (C-11). The hip lateral swing piston assembly (C-12) is connected to the lateral swing slider. During the extension and retraction of the hip lateral swing piston assembly (C-12), the lateral swing two-force bar (C-9) is driven to move up and down through the vertical sliding of the lateral swing slider, thereby driving the thigh connector (D) to achieve lateral swing.

7. A compact hydraulically driven integrated lumbar and hip pelvic structure according to claim 6, characterized in that: The waist slider (A-5), yaw slider (C-5), and side-swing slider have a longitudinal cross-section shape of "⊥" on one side.

8. A compact hydraulically driven integrated lumbar and hip pelvic structure according to claim 7, characterized in that: The thigh connector (D) is a hollow cylindrical structure.

Images