Robot leg structure based on planetary roller screw linear joints and connecting rods
By using a robot leg structure based on planetary roller screw linear joints and linkages, the problems of insufficient rigidity and high power consumption in existing technologies are solved, achieving high load-bearing capacity, low power consumption and self-locking characteristics, and stable working ability to adapt to various environments.
Patent Information
- Application Number
- CN202511373343.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-24
- Publication Date
- 2025-12-19
AI Technical Summary
Existing humanoid robot leg structures suffer from insufficient rigidity, high power consumption, and limited range of motion during dynamic movement, making it difficult to operate stably in various environments.
The robot leg structure adopts a planetary roller screw linear joint and linkage. Two actuators drive two linkage mechanisms to realize the rotation of the thigh and lower leg, and the lower leg actuator completes the foot movement. The structure is simple and ingenious, with high load-bearing capacity, high power and self-locking characteristics.
It achieves the ability to work continuously and stably in a variety of environments, supports high-dynamic movements such as running and jumping, has flexible feet and is not prone to loss of balance, and adapts to various terrains.
Smart Images
Figure CN121158079A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of robots, and more particularly relates to a robot leg structure based on a planetary roller screw linear joint and a connecting rod. BACKGROUND
[0002] Common humanoid robot leg structures are mainly divided into two types of configurations, namely, a series structure and a parallel structure. The series structure simulates the arrangement of human limbs, has a large workspace and the ability to realize flexible gait, but the joint error is cumulatively accumulated, the rigidity is insufficient during dynamic motion, and the total power consumption is relatively high. The parallel structure adopts a closed-loop branch chain, and the rigidity and positioning accuracy are significantly improved through the cooperation of multiple drivers. The design of moving the driver upward significantly reduces the leg inertia, and the energy efficiency is improved by 30% compared with the series structure. However, the motion range is limited by the interference of the connecting rod, and the control algorithm needs to solve the problem of decoupling of multiple branch chains. In order to enhance the adaptability of robots to various environments, many new types of robot leg structures have been proposed. The most typical example is the leg design of Tesla Optimus, which first introduces planetary roller screws on a large scale in a humanoid robot. This structure combines bionic structure optimization and high energy control, significantly reduces the peak torque demand of high-load actions such as deep squatting, and makes joint motion more smooth and energy-saving. The linear actuators arranged longitudinally are closely integrated into the thigh, calf and ankle joints, and cooperate with the planetary roller screws to realize mechanical self-locking function, while providing a load support capacity of up to half a ton. The bionic foot adopts a curved foot bottom and a flexible toe structure, which cooperates with a multi-dimensional torque sensor to adjust the gait in real time, effectively improving the adaptability to complex terrains such as slopes.
[0003] The reason why the robot using the planetary roller screw has strong applicability can be attributed to the special structure of the planetary roller screw and the connecting rod knee joint structure. In order to further expand the application range of the robot using the planetary roller screw, the present application proposes a robot leg structure based on a planetary roller screw linear joint and a connecting rod. SUMMARY
[0004] The technical problem to be solved by the present application is to provide a robot leg structure based on a planetary roller screw linear joint and a connecting rod, which has multiple advantages such as high load capacity, high power, miniaturization and self-locking characteristics, and can realize continuous and stable work in various environments.
[0005] To solve the above technical problems, the technical solution adopted by the present application is: a robot leg structure based on a planetary roller screw linear joint and a connecting rod, comprising a first connecting piece, a second connecting piece, a thigh shell, a first driver, a second driver, a calf shell, a calf driver, a third connecting piece, a first support, a second support and a foot plate.
[0006] The first connector is rotatably connected to the second connector via a pivot. The second connector is rotatably connected to both ends of the first linkage mechanism via the first pivot and the second pivot, respectively. One end of the second driver is rotatably connected to the first linkage mechanism via a third pivot, and the other end is rotatably connected to the thigh shell via a pivot. The second connector is rotatably connected to the thigh shell via the first pivot, and the first pivot is fixedly connected to the thigh shell. The second driver drives the first linkage mechanism to rotate around the first pivot and the second pivot, thereby changing the angle between the thigh shell and the second connector.
[0007] One end of the first actuator is rotatably connected to the thigh shell via a rotating shaft, and the other end is rotatably connected to the second linkage mechanism via a sixth rotating shaft. The thigh shell is rotatably connected to the calf shell via a fourth rotating shaft, and the calf shell is rotatably connected to both ends of the second linkage mechanism via a fifth rotating shaft and an eighth rotating shaft, respectively. The first actuator drives the second linkage mechanism, and the second linkage mechanism causes the calf shell to rotate relative to the thigh shell around the fourth rotating shaft, thereby changing the angle between the thigh shell and the calf shell.
[0008] The lower leg shell is rotatably connected to one end of the lower leg actuator via a pivot. The other end of the lower leg actuator is rotatably connected to the first support via a pivot. The first support is fixedly connected to the top of the foot plate. The bottom of the lower leg shell is rotatably connected to the third connector via a pivot. The third connector is rotatably connected to the second support via a pivot. The second support is fixedly connected to the top of the foot plate. The lower leg actuator drives the lower leg shell to rotate around the third connector, thereby changing the angle between the foot plate and the lower leg shell.
[0009] Preferably, the first linkage mechanism includes a second link, a third link, and a sixth link. One end of the second link is rotatably connected to a second connecting member via a second rotating shaft, and the other end is rotatably connected to one end of the third link via a third rotating shaft. The other end of the third link is rotatably connected to one end of the sixth link via a seventh rotating shaft. The other end of the sixth link is rotatably connected to the second connecting member via a first rotating shaft. The sixth link is fixedly connected to the first rotating shaft, and the first rotating shaft is fixedly connected to the thigh shell. The second driver is rotatably connected to the second link and the third link via the third rotating shaft. The second link, the third link, the sixth link, and the second connecting member form a four-bar linkage mechanism.
[0010] Preferably, the second linkage mechanism includes a first link, a fourth link, and a fifth link. One end of the first link is rotatably connected to the lower leg shell via a fifth pivot, and the other end is rotatably connected to one end of the fourth link via a sixth pivot. The other end of the fourth link is rotatably connected to one end of the fifth link via a fourth pivot. The other end of the fifth link is rotatably connected to the lower leg shell via an eighth pivot. The lower leg shell is rotatably connected to the thigh shell via a fourth pivot. The first driver is rotatably connected to the first link and the fourth link via a sixth pivot. The first link, the fourth link, the fifth link, and the lower leg shell form a four-bar linkage mechanism.
[0011] Preferably, the first actuator, the second actuator, and the lower leg actuator are all retractable devices.
[0012] Preferably, the telescopic device includes a housing, a planetary roller screw, a push rod, and a motor. The planetary roller screw consists of a screw and a sleeve. Both the planetary roller screw and the motor are installed inside the housing. The output shaft of the motor is fixedly connected to the screw, and the sleeve is fixedly connected to the push rod. The motor drives the screw to rotate, and the screw drives the sleeve and the push rod to move.
[0013] Preferably, the first actuator, the second actuator, and the lower leg actuator are all electric actuators.
[0014] The beneficial effects of adopting the above technical solution are as follows: The present invention has a simple and ingenious structure. It uses two actuators to drive two linkage mechanisms to complete the mutual rotation of the robot's thigh and calf, and thigh and waist. It also uses the calf actuator to complete the movement of the calf and foot. It has multiple advantages such as high load-bearing capacity, high power, miniaturization and self-locking characteristics. Compared with existing products, it can support high dynamic movements such as running and jumping. Moreover, the feet are flexible, wide and not easy to lose balance. It can adapt to various terrains and achieve continuous and stable work in various environments. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the leg structure in an upright position;
[0016] Figure 2 This is a schematic diagram of the connection between two linkage mechanisms;
[0017] Figure 3 This is a diagram illustrating the leg structure during walking.
[0018] In the diagram: 1. First connector, 2. Second connector, 3. First pivot, 4. Thigh shell, 5. First actuator, 6. First link, 7. Lower leg shell, 8. Lower leg actuator, 9. Third connector, 10. First support, 11. Second support, 12. Second pivot, 13. Second link, 14. Third pivot, 15. Third link, 16. Second actuator, 17. Fourth link, 18. Fourth pivot, 19. Fifth link, 20. Fifth pivot, 21. Sixth pivot, 22. Seventh pivot, 23. Sixth link, 24. Foot plate, 25. Eighth pivot. Detailed Implementation
[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0020] like Figure 1 As shown, the robot's leg structure includes a first connector 1, a second connector 2, a thigh shell 4, a first actuator 5, a second actuator 16, a lower leg shell 7, a lower leg actuator 8, a third connector 9, a first support 10, a second support 11, and a foot plate 24. The upper part of the first connector 1 is connected to the robot's waist structure, and the lower part is connected to two second connectors 2. One leg structure is installed under each second connector 2.
[0021] like Figure 2 As shown, one end of the second actuator 16 is rotatably connected to the thigh shell 4 via a pivot, and the telescopic end is rotatably connected to the second link 13 and the third link 15 via a third pivot 14. One end of the second link 13 is rotatably connected to the second connector 2 via a second pivot 12, and the other end is rotatably connected to one end of the third link 15 via a third pivot 14. The other end of the third link 15 is rotatably connected to one end of the sixth link 23 via a seventh pivot 22. The sixth link 23 is fixedly connected to the first pivot 3 and is rotatably connected to the second connector 2 via the first pivot 3. The second link 13, the third link 15, the sixth link 23, and the second connector 2 form a four-bar linkage. The first pivot 3 is also fixedly connected to the thigh shell 4. When the second actuator 16 extends or retracts, it drives the four-bar linkage to rotate around the first pivot 3. The sixth link 23 drives the first pivot 3 to rotate, and the first pivot 3 drives the thigh shell 4 to rotate, thereby changing the angle between the thigh shell 4 and the second connector 2.
[0022] like Figure 2 As shown, one end of the first link 6 is rotatably connected to the lower leg shell 7 via the fifth pivot 20, and the other end is rotatably connected to one end of the fourth link 17 via the sixth pivot 21. The other end of the fourth link 17 is rotatably connected to one end of the fifth link 19 via the fourth pivot 18, and the other end of the fifth link 19 is rotatably connected to the lower leg shell 7 via the eighth pivot 25. The thigh shell 4 is rotatably connected to the lower leg shell 7 via the fourth pivot 18. The first link 6, the fourth link 17, the fifth link 19, and the lower leg shell 7 form a four-bar linkage. The first actuator 5 extends and retracts, causing the four-bar linkage to rotate around the fourth pivot 18, thereby causing the lower leg shell 7 to rotate and changing the angle between the thigh shell 4 and the lower leg shell 7.
[0023] like Figure 3As shown, the lower leg shell 7 is rotatably connected to one end of the lower leg actuator 8 via a pivot, and the other end of the lower leg actuator 8 is rotatably connected to the first support 10 via a pivot. The first support 10 is fixedly connected to the top of the foot plate 24. The bottom of the lower leg shell 7 is rotatably connected to the third connector 9 via a pivot, and the third connector 9 is rotatably connected to the second support 11 via a pivot. The second support 11 is fixedly connected to the top of the foot plate 24. The lower leg actuator 8 drives the lower leg shell 7 to rotate around the third connector 9, thereby changing the angle between the foot plate 24 and the lower leg shell 7. In this embodiment, the lower leg actuator 8 is provided with two...
[0024] like Figure 1 As shown, the first actuator 5, the second actuator 16, and the lower leg actuator 8 are all telescopic devices. Each telescopic device includes a housing, a planetary roller screw, a push rod, and a motor. The planetary roller screw consists of a screw and a sleeve. Both the planetary roller screw and the motor are installed inside the housing (the planetary roller screw and motor are not shown in the drawing). The motor's output shaft is fixedly connected to the screw, and the sleeve is fixedly connected to the push rod. The motor drives the screw to rotate, and the screw drives the sleeve and the push rod to move.
[0025] The first actuator 5, the second actuator 16, and the lower leg actuator 8 can also be electric actuators.
[0026] When the lower leg and thigh are parallel, it is a standing posture, such as... Figure 1 As shown. When the heel and forefoot are not on the same plane, it is a walking posture, as shown... Figure 3 As shown, the robot's legs move back and forth continuously, propelling the robot forward.
[0027] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A robot leg structure based on a planetary roller screw linear joint and connecting rod, characterized in that, It includes a first connector (1), a second connector (2), a thigh shell (4), a first driver (5), a second driver (16), a lower leg shell (7), a lower leg driver (8), a third connector (9), a first support (10), a second support (11), and a foot plate (24); The first connecting member (1) is rotatably connected to the second connecting member (2) via a rotating shaft. The second connecting member (2) is rotatably connected to both ends of the first linkage mechanism via the first rotating shaft (3) and the second rotating shaft (12), respectively. One end of the second driver (16) is rotatably connected to the first linkage mechanism via the third rotating shaft (14), and the other end is rotatably connected to the thigh shell (4) via a rotating shaft. The second connecting member (2) is rotatably connected to the thigh shell (4) via the first rotating shaft (3), and the first rotating shaft (3) is fixedly connected to the thigh shell (4). The second driver (16) drives the first linkage mechanism to rotate around the first rotating shaft (3) and the second rotating shaft (12), thereby changing the angle between the thigh shell (4) and the second connecting member (2). One end of the first driver (5) is rotatably connected to the thigh shell (4) via a pivot, and the other end is rotatably connected to the second linkage mechanism via a sixth pivot (21). The thigh shell (4) is rotatably connected to the calf shell (7) via a fourth pivot (18). The calf shell (7) is rotatably connected to both ends of the second linkage mechanism via a fifth pivot (20) and an eighth pivot (25), respectively. The first driver (5) drives the second linkage mechanism, which in turn causes the calf shell (7) to rotate relative to the thigh shell (4) around the fourth pivot (18), thereby changing the angle between the thigh shell (4) and the calf shell (7). The lower leg shell (7) is rotatably connected to one end of the lower leg actuator (8) via a pivot. The other end of the lower leg actuator (8) is rotatably connected to the first support (10) via a pivot. The first support (10) is fixedly connected to the top of the foot plate (24). The bottom of the lower leg shell (7) is rotatably connected to the third connector (9) via a pivot. The third connector (9) is rotatably connected to the second support (11) via a pivot. The second support (11) is fixedly connected to the top of the foot plate (24). The lower leg actuator (8) drives the lower leg shell (7) to rotate around the third connector (9), thereby changing the angle between the foot plate (24) and the lower leg shell (7).
2. The robot leg structure based on a planetary roller screw linear joint and connecting rod according to claim 1, characterized in that, The first linkage mechanism includes a second link (13), a third link (15), and a sixth link (23). One end of the second link (13) is rotatably connected to the second connector (2) via a second pivot (12), and the other end is rotatably connected to one end of the third link (15) via a third pivot (14). The other end of the third link (15) is rotatably connected to one end of the sixth link (23) via a seventh pivot (22). The other end of the sixth link (23) is rotatably connected to the second connector (2) via a first pivot (3). The sixth link (23) is fixedly connected to the first pivot (3), and the first pivot (3) is fixedly connected to the thigh shell (4). The second driver (16) is rotatably connected to the second link (13) and the third link (15) via the third pivot (14). The second link (13), the third link (15), the sixth link (23), and the second connector (2) form a four-bar linkage mechanism.
3. The robot leg structure based on a planetary roller screw linear joint and connecting rod according to claim 1, characterized in that, The second linkage mechanism includes a first link (6), a fourth link (17), and a fifth link (19). One end of the first link (6) is rotatably connected to the lower leg shell (7) via a fifth pivot (20), and the other end is rotatably connected to one end of the fourth link (17) via a sixth pivot (21). The other end of the fourth link (17) is rotatably connected to one end of the fifth link (19) via a fourth pivot (18). The other end of the fifth link (19) is rotatably connected to the lower leg shell (7) via an eighth pivot (25). The lower leg shell (7) is rotatably connected to the thigh shell (4) via a fourth pivot (18). The first driver (5) is rotatably connected to the first link (6) and the fourth link (17) via a sixth pivot (21). The first link (6), the fourth link (17), the fifth link (19), and the lower leg shell (7) form a four-bar linkage mechanism.
4. The robot leg structure based on a planetary roller screw linear joint and connecting rod according to claim 1, characterized in that, The first actuator (5), the second actuator (16), and the lower leg actuator (8) are all retractable devices.
5. A robot leg structure based on a planetary roller screw linear joint and connecting rod according to claim 4, characterized in that, The telescopic device includes a housing, a planetary roller screw, a push rod, and a motor. The planetary roller screw consists of a screw and a sleeve. Both the planetary roller screw and the motor are installed inside the housing. The output shaft of the motor is fixedly connected to the screw, and the sleeve is fixedly connected to the push rod. The motor drives the screw to rotate, and the screw drives the sleeve and the push rod to move.
6. A robot leg structure based on a planetary roller screw linear joint and connecting rod according to claim 4, characterized in that, The first actuator (5), the second actuator (16), and the lower leg actuator (8) are all electric actuators.