A three-degree-of-freedom hip system for a new type of humanoid robot

Abstract

The present application relates to a kind of new humanoid robot three degrees of freedom hip system, belong to intelligent robot field.The system includes femoral skeleton, main base, lateral roll joint module, yaw joint module, pitch base assembly, planetary roller screw assembly, main connecting rod and vice connecting rod.Pitch movement is realized through planetary roller screw assembly, lateral roll joint module realizes lateral roll movement, and yaw joint module realizes yaw movement.The present application solves the problems of low load capacity, heavy weight, large size, inconvenient assembly, unstable walking and other problems in the prior art by optimizing the structure design, and is suitable for various application scenarios such as industrial handling, rehabilitation training and the like.

Description

Technical Field

[0001] This invention relates to a novel three-degree-of-freedom hip system for a humanoid robot, belonging to the field of intelligent robots. Background Technology

[0002] (1) Application background of the present invention:

[0003] The hip design of humanoid robots needs to meet the requirements of various application scenarios. For example, the Optimus humanoid robot uses a hybrid of rotary and linear actuators in its hip joint, enabling it to perform heavy-duty tasks such as material handling in industrial settings. Furthermore, some assistive exoskeleton robots also employ similar hip joint designs to assist stroke patients in rehabilitation training. The hip of a humanoid robot is a key component enabling walking, balance, and complex movements. Below is a detailed introduction to the hip of humanoid robots:

[0004] a. Structure and Degrees of Freedom:

[0005] Multi-degree-of-freedom design: To mimic the complex movements of the human hip, humanoid robots typically have multiple degrees of freedom in their hip joints. Generally, each hip has at least three degrees of freedom, corresponding to the three main directions of movement: flexion / extension (moving the leg forward and backward), abduction / adduction (moving the leg away from or towards the body's midline), and internal / external rotation (rotating the leg about its axis).

[0006] Spherical joint type: In some designs, the robot's hip and shoulder joints are treated as 3-DOF spherical joints, and motion redirection is achieved by copying the corresponding joint rotation angles from human motion data to the robot joints.

[0007] b. Driving method:

[0008] Motor drive: Electric motors are commonly used actuators to drive hip joint movements. Motor drives can provide precise control and high torque output, meeting the needs of the hip joint in different movement scenarios.

[0009] Hydraulic drive: Hydraulic actuators are also used to drive the hip joint, characterized by high force and fast response. For example, the hydraulic drive system designed by Wang Jicai et al. for human weight-bearing exoskeletons has proven through experiments to operate smoothly and with low impact.

[0010] Flexible actuation: To improve the walking performance and control efficiency of humanoid robots, some studies have proposed incorporating the alternating flexion and extension motion characteristics of the human hip joints, designing a flexible actuation device for the hip joint using a cam as the drive and a flexible cable as the elastic element. This flexible actuation method can make the robot's movement more natural and flexible.

[0011] (2) Disadvantages of the prior art related to this invention:

[0012] When designing the hip joint of a humanoid robot, multiple factors need to be considered, including balance, dynamic motion control, and high load capacity. Simultaneously, the size and weight of the joint limit the output torque of the motor and the reduction ratio of the planetary reducer, thus affecting the torque density at the joint end. Furthermore, improving the safety, compliance, stability, and adaptability of the joint in complex environments are also significant challenges. The main drawbacks include: limited load capacity, significant weight, large size, inconvenient assembly and disassembly, unstable walking, and a high risk of falls. Summary of the Invention

[0013] To overcome the shortcomings of the prior art, the present invention provides a novel three-degree-of-freedom hip system for a humanoid robot, specifically adopting the following technical solution:

[0014] A novel three-degree-of-freedom hip system for a humanoid robot, characterized in that it comprises:

[0015] The thigh skeleton (1) serves as the load-bearing structure of the hip system;

[0016] Main base assembly (2) for fixing the roll joint module (3);

[0017] The roll joint module (3) is locked onto the main base (2) by fastening screw A (14), and the quick-release connector (3-2) at the output end of the roll joint is connected to the yaw joint module (4) to realize the transmission of power and communication signals.

[0018] The yaw joint module (4) is fixed to the yaw joint base (4-1) by fastening screw C (16), and the quick-release connector (4-3) at the output end of the yaw joint is connected to the pitch base assembly to realize the transmission of power and communication signals.

[0019] The pitch base assembly includes a pitch base (19), which is locked to the thigh skeleton on both sides by pitch fastening shafts (24) and fastening screws F (23), and the pitch base is connected to the force sensor (7) by a main support shaft (35).

[0020] The planetary roller screw assembly includes a base end spherical bearing (12), an end cap force sensor (11), a planetary roller screw (9), a planetary roller screw (10), and an output end spherical bearing (22), wherein the base end spherical bearing is fixed to the thigh skeleton by a locking shaft (36) and a hexagonal lock nut (37);

[0021] The main link (5) and the secondary link (6) are connected. The other end of the main link is fixedly connected to the thigh skeleton, and the other end of the secondary link is connected to the pitch base through the force sensor (7).

[0022] Force sensor (7) is connected to main support shaft (35) via needle roller bearing (34), and the outer end face of force sensor is restricted from axial movement by polytetrafluoroethylene pad B (21); wherein, the planetary roller screw assembly drives the main connecting rod and the secondary connecting rod to move through reciprocating linear motion to realize the pitching motion of the hip; the roll joint module realizes the roll motion of the hip through motor drive; the yaw joint module realizes the yaw motion of the hip through motor drive.

[0023] This invention also discloses a method for realizing three-degree-of-freedom motion, characterized by comprising the following steps:

[0024] Pitch motion: The output end joint bearing (22) of the planetary roller screw (9) drives the main drive shaft (33) to move. The main drive shaft drives the main connecting rod (5) to rotate around the fixed point on the thigh skeleton. The main drive shaft simultaneously drives the auxiliary connecting rod (6) and the force sensor (7) to move. The force sensor transmits the force to the pitch base (19) through the needle roller bearing (34), so that the pitch base can perform pitch motion around the axis of the pitch fastening shaft (24).

[0025] Rolling motion: The roll joint module (3) is driven by a motor to drive the yaw joint module (4) and the pitch base assembly to rotate around the roll axis, thereby realizing the rolling motion of the hip.

[0026] Yaw motion: The yaw joint module (4) is driven by a motor to rotate the pitch base assembly around the yaw axis, thereby realizing the yaw motion of the hip.

[0027] The present invention also discloses a humanoid robot, characterized in that it includes the three-degree-of-freedom hip system as described above, which is suitable for applications such as industrial handling and rehabilitation training.

[0028] Beneficial effects

[0029] a. Improve the load-bearing capacity of the hips of humanoid robots;

[0030] b. Reduce the weight of humanoid robots;

[0031] c. Reduce the size of humanoid robots;

[0032] a) Improve the efficiency of assembling and disassembling humanoid robots;

[0033] b) Improve the load capacity / weight ratio;

[0034] c) Improve the stability of humanoid robot walking. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the hip assembly of the present invention;

[0036] Figure 2 This is a schematic diagram of the assembly of the main base and the roll joint module of the present invention;

[0037] Figure 3 This is a schematic diagram of the yaw power component of the present invention;

[0038] Figure 4 This is a schematic diagram of the pitch base assembly of the present invention;

[0039] Figure 5 This is a schematic diagram of the hip pitch linkage transmission of the present invention;

[0040] Figure 6 for Figure 5 EE sectional view;

[0041] Figure 7 for Figure 5 FF sectional view;

[0042] In the diagram: 1. Thigh frame, 2. Main base assembly, 3. Roll joint module, 4. Yaw joint module, 5. Main connecting rod, 6. Secondary connecting rod, 7. Force sensor, 8. PTFE pad A, 9. Planetary roller screw, 10. Planetary roller screw, 11. End cap force sensor, 12. Base end spherical bearing, 13. Wiring harness support rod, 14. Fastening screw A, 15. Fastening screw B, 16. Fastening screw C, 17. Fastening screw D, 18. Fastening screw E, 19. Pitch base, 20. Angular contact ball bearing A, 21. PTFE pad B, 22. Output end spherical bearing, 23. Fastening screw F, 24. Pitch fastening shaft, 2 5. Secondary support shaft; 26. Anti-loosening washer C; 27. Anti-loosening washer B; 28. Anti-loosening nut B; 29. ​​Anti-loosening nut A; 30. Anti-loosening washer A; 31. Secondary drive shaft; 32. Angular contact ball bearing B; 33. Main drive shaft; 34. Needle roller bearing; 35. Main support shaft; 36. Locking shaft; 37. Hexagonal anti-loosening nut; 38. Anti-loosening washer; 3-1. Quick-release connector at the input end of the roll joint; 3-2. Quick-release connector at the output end of the roll joint; 4-1. Yaw joint base; 4-2. Quick-release connector at the input end of the yaw joint; 4-3. Quick-release connector at the output end of the yaw joint; 33-1. First end face of the main drive shaft; 33-2. Second end face of the main drive shaft. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Please see Figure 1-7 This invention provides a technical solution: a novel three-degree-of-freedom hip system for a humanoid robot, such as... Figure 1 As shown, it includes a thigh skeleton 1, a main base assembly 2, a roll joint module 3, a yaw joint module 4, a pitch base assembly, a planetary roller screw assembly, a main connecting rod 5, and a secondary connecting rod 6.

[0045] The thigh skeleton is the load-bearing structure of the hip system. The base end joint bearing of the planetary roller screw assembly is connected to the thigh skeleton and is fixedly connected to the pitch base 19 by the pitch fastening shaft 24 and the fastening screw F23.

[0046] Main connecting rod 5 and secondary connecting rod 6: The other end of the main connecting rod 5 is fixedly connected to the thigh frame 1, and the other end of the secondary connecting rod 6 is connected to the pitch base 19 through the force sensor 7; the planetary roller screw assembly includes a base end spherical bearing 12, an end cap force sensor 11, a planetary roller screw 9, a planetary roller screw 10, and an output end spherical bearing 22. The base end spherical bearing 12 is fixed to the thigh frame 1 through a locking shaft 36 and a hexagonal anti-loosening nut 37; the output end spherical bearing of the planetary roller screw assembly is connected to the main connecting rod and the secondary connecting rod, and the other end of the main connecting rod is fixedly connected to the thigh frame 1; the other end of the secondary connecting rod is connected to the pitch base through the force sensor, and the pitch base is locked to the thigh frame through a pitch fastening shaft and a fastening screw F.

[0047] Reference Figure 2 The roll joint module is secured to the main base with fastening screw A. The quick-release connector at the roll joint output end connects to the yaw joint module, thereby transmitting the power and communication signals from the roll joint module to the yaw joint module. The quick-release connector design simplifies installation and facilitates future maintenance or rapid replacement of the joint modules.

[0048] like Figure 3 As shown, the yaw power assembly includes a yaw joint base (4-1) and a yaw joint module (4). The yaw joint module is fixed to the yaw joint base by fastening screws C (16), and the quick-release connector (4-3) at the output end of the yaw joint is connected to the pitch base assembly, thereby transmitting the power and communication signals of the yaw joint module to the pitch base assembly. The roll joint module (3) is locked to the main base (2) by fastening screws A (14), and the quick-release connector (3-1) at the input end of the roll joint receives the motor control signal; the roll joint module (3) is connected to the yaw joint module through the quick-release connector (3-2) at the output end of the roll joint to realize the transmission of power and communication signals.

[0049] Working principle of roll joint module and yaw joint module: Roll joint module (3) realizes the roll motion of hip through motor drive. The motor drives the quick-release connector (3-2) of roll joint output end to rotate through reducer and transmission mechanism, thereby driving yaw joint module (4) and pitch base assembly to rotate around roll axis. The motor control signal of roll joint module is received through quick-release connector (3-1) of roll joint input end, and the power and communication signals are transmitted to yaw joint module through quick-release connector (3-2) of roll joint output end.

[0050] Working principle of the yaw joint module: The yaw joint module (4) is fixed on the yaw joint base (4-1) by fastening screw C (16). The yaw joint module (4) realizes the yaw movement of the hip by the motor drive. The motor drives the quick-release connector (4-3) at the output end of the yaw joint to rotate through the reducer and transmission mechanism, thereby driving the pitch base assembly to rotate around the yaw axis and realize the yaw movement of the hip. The motor control signal of the yaw joint module is received through the quick-release connector (4-2) at the input end of the yaw joint, and the power and communication signals are transmitted to the pitch base assembly through the quick-release connector (4-3) at the output end of the yaw joint.

[0051] The roll and yaw joint modules utilize quick-release connectors for rapid power and communication signal transmission, facilitating assembly and maintenance. Their motor-driven design provides precise control and high torque output, meeting the hip joint's needs in various motion scenarios. The compact structure of the roll and yaw joint modules reduces weight and volume, improving the load capacity / weight ratio. The rationally designed transmission mechanism enhances motion control accuracy and effectiveness, reducing lag caused by insufficient rigidity in the transmission mechanism.

[0052] like Figure 4 As shown, the pitch base assembly includes a pitch base, on which two angular contact ball bearings A are placed. The outer rings of the two angular contact ball bearings A are fixedly mounted on the bearing mounting seats of the pitch base by an interference fit, and are positioned by a step at the bottom of the bearing mounting seats to restrict the axial movement of the outer rings of the angular contact ball bearings A. The pitch base is locked to the thigh frame on both sides by two pitch fastening shafts and several fastening screws F. Specifically, one end face of the pitch fastening shaft is in contact with the thigh frame, and the other end face is in contact with the inner ring end face of the angular contact ball bearing A. The large end face of the pitch fastening shaft is fixed to the thigh frame by several fastening screws F. The back-to-back placement of the two angular contact ball bearings A not only improves the axial and radial load capacity, but also prevents the thigh frame from being damaged under certain torsional loads, and improves the impact resistance of the main connecting rod, the auxiliary connecting rod, and the force sensor.

[0053] The pitch base is connected to the force sensor fixed to the other end of the auxiliary connecting rod via the main support shaft.

[0054] The pitch base is fixedly connected to the output end of the yaw joint module by fastening screw D.

[0055] The other end of the secondary link is connected to a force sensor. The force sensor can monitor the magnitude of the thrust acting directly on the pitch base in real time, thereby calculating the pitch torque of the hip joint in real time. This improves the accuracy and real-time performance of hip motion control in the humanoid robot. The specific connection method between the secondary link and the force sensor is as follows: the end face of the force sensor is in contact with the secondary link and locked by anti-loosening washer B and anti-loosening nut B. The end face of the force sensor not only serves as an axial limit but also as a stop, preventing the force sensor from rotating along the axial direction.

[0056] The other end of the force sensor is connected to the pitch base via the main support shaft. Specifically, a needle roller bearing is nested at the other end of the force sensor. The outer ring of this needle roller bearing is fixed by a retaining ring through the force sensor and the hole. The inner ring of this needle roller bearing 34 is held and fixed by the end faces of the main support shaft 35 and the auxiliary support shaft, and is locked by anti-loosening washers C and fastening screws E. The fastening screws E are directly locked onto the main support shaft, making installation simple and convenient. Both the main support shaft and the auxiliary support shaft are fixed to the pitch base. The outer end face of the force sensor 7 is restricted from axial movement by a PTFE pad B. The rotational resistance of the force sensor can be adjusted by adjusting the thickness of the PTFE pad B, allowing the robot to have a certain holding force. In addition, the PTFE pad B can reduce assembly clearance and improve motion control accuracy.

[0057] The other end of the main connecting rod is fixed to the thigh frame, and axial movement is restricted by two PTFE pads A. Its connection method is the same as that of the secondary connecting rod and the force sensor.

[0058] The planetary roller screw assembly includes a base end spherical bearing, an end cap force sensor, a planetary roller screw, and an output end spherical bearing. The base end spherical bearing is fixed to the thigh frame via a locking shaft, an anti-loosening washer, and a hexagonal anti-loosening nut. The locking method is as follows: the locking shaft passes sequentially through the anti-loosening washer, the shaft hole of the thigh frame, the base end spherical bearing, another shaft hole of the thigh frame, and the hexagonal anti-loosening nut. The hexagonal anti-loosening nut is fixed within the hexagonal hole for better locking and anti-loosening. The base end spherical bearing is locked by adjusting the engagement depth of the locking shaft and the hexagonal anti-loosening nut, eliminating clearances caused by machining and installation, and improving position control accuracy.

[0059] The output end spherical plain bearing, main connecting rod, and auxiliary connecting rod are fixedly connected via the main drive shaft, angular contact ball bearing B, and auxiliary drive shaft. Specifically, the main drive shaft passes sequentially through angular contact ball bearing B, one shaft hole of the main connecting rod, the output end spherical plain bearing, the other shaft hole of the main connecting rod, the auxiliary drive shaft, and another angular contact ball bearing B, and is locked in place by anti-loosening washer A and anti-loosening nut A. The outer rings of the two angular contact ball bearings B are fixedly mounted on the two bearing mounting seats of the auxiliary connecting rod via interference fit, and are positioned by the steps at the bottom of the bearing mounting seats to restrict axial movement. The inner rings of the two angular contact ball bearings B are fixed to the main drive shaft and auxiliary drive shaft via interference fit, and are positioned by the first end face of the main drive shaft and the end face of the auxiliary drive shaft to restrict axial movement of the inner rings. Furthermore, the main drive shaft is fitted inside the auxiliary drive shaft. This design not only reduces the installation difficulty of the main drive shaft but also avoids assembly difficulties caused by low coaxiality accuracy of the main drive shaft.

[0060] In the design of the main drive shaft (33) and the auxiliary drive shaft (31), the axial preload of a pair of angular contact ball bearings B (32) can be precisely adjusted by adjusting the distance between the first end face (33-1) and the second end face (33-2) of the main drive shaft, as well as the end face length of the auxiliary drive shaft. This adjustment method can effectively improve the axial stiffness of the main connecting rod (5) and improve the installation accuracy, thereby enhancing the accuracy and effect of motion control. The adjustment process of adjusting the distance between the first end face and the second end face of the main drive shaft:

[0061] The first end face (33-1) of the main drive shaft (33) is fixed in contact with the inner ring of the angular contact ball bearing B (32), and the second end face (33-2) is fixed in contact with the end face of the main connecting rod (5). By adjusting the distance between the first end face (33-1) and the second end face (33-2) of the main drive shaft, the axial clearance between the inner ring of the angular contact ball bearing B (32) and the main connecting rod (5) can be changed. Specific adjustment method:

[0062] Loosen the anti-loosening nut A (29) and anti-loosening washer A (30): Use a special tool (such as an adjusting shim or adjusting nut) to adjust the distance between the first end face (33-1) and the second end face (33-2) of the main drive shaft; accurately measure the adjusted distance with a measuring tool (such as a micrometer) to ensure that it meets the design requirements; re-tighten the anti-loosening nut A (29) and anti-loosening washer A (30) to ensure that the adjusted position is fixed.

[0063] The axial preload of the angular contact ball bearing B (32) is changed by adjusting the distance between the first end face (33-1) and the second end face (33-2) of the main drive shaft. When the distance decreases, the inner ring of the angular contact ball bearing B (32) is subjected to greater axial pressure, and the preload increases, thereby improving the axial stiffness and motion accuracy of the main connecting rod (5). When the distance increases, the axial pressure on the inner ring of the angular contact ball bearing B (32) decreases, and the preload decreases, which is suitable for scenarios that require greater flexibility.

[0064] The end face length of the auxiliary drive shaft (31) directly affects the axial clearance between the inner ring of the angular contact ball bearing B (32) and the main drive shaft (33). The adjustment process of the end face length of the auxiliary drive shaft is as follows:

[0065] Loosen the lock nut B (28) and lock washer B (27); use a special tool (such as an adjusting shim or adjusting nut) to adjust the end face length of the auxiliary drive shaft (31); measure the adjusted length precisely with a measuring tool (such as a micrometer) to ensure that it meets the design requirements; re-tighten the lock nut B (28) and lock washer B (27) to ensure that the adjusted position is fixed.

[0066] When the end face length of the secondary drive shaft (31) increases, the inner ring of the angular contact ball bearing B (32) is subjected to greater axial pressure, and the preload increases, thereby improving the axial stiffness and motion accuracy of the main connecting rod (5). When the end face length of the secondary drive shaft (31) decreases, the axial pressure on the inner ring of the angular contact ball bearing B (32) decreases, and the preload decreases, making it suitable for scenarios requiring greater flexibility.

[0067] In the actual adjustment process, the distance between the first end face (33-1) and the second end face (33-2) of the main drive shaft and the end face length of the auxiliary drive shaft (31) need to be adjusted in coordination to achieve the optimal axial preload. The adjustment process of the axial preload is as follows:

[0068] Loosen lock nut A (29), lock washer A (30), lock nut B (28), and lock washer B (27); Use a special tool to simultaneously adjust the distance between the first end face (33-1) and the second end face (33-2) of the main drive shaft, as well as the end face length of the auxiliary drive shaft (31); Use a measuring tool to accurately measure the adjusted distance and length to ensure that they meet the design requirements; Re-tighten lock nut A (29), lock washer A (30), lock nut B (28), and lock washer B (27) to ensure that the adjusted position is fixed.

[0069] Effects after adjustment: Improved axial stiffness: By increasing the axial preload of the angular contact ball bearing B (32), the axial stiffness of the main connecting rod (5) is significantly improved, enabling it to withstand greater axial loads; Improved installation accuracy: Precise adjustment of the end face distance and length of the main drive shaft and the auxiliary drive shaft can reduce assembly errors and improve installation accuracy; Improved motion control accuracy: By optimizing the axial preload, the lag caused by insufficient rigidity in the mechanism transmission is reduced, thereby improving the accuracy and effect of motion control; Extended service life: Reasonable axial preload can reduce the wear of the angular contact ball bearing B (32) and extend its service life.

[0070] By adjusting the distance between the first end face (33-1) and the second end face (33-2) of the main drive shaft, as well as the end face length of the auxiliary drive shaft (31), the axial preload of the angular contact ball bearing B (32) can be precisely adjusted, thereby improving the axial stiffness, installation accuracy, and motion control accuracy of the main connecting rod (5). This adjustment method is simple and reliable, and can effectively solve the problems of insufficient rigidity, large assembly error, and low motion control accuracy existing in the prior art.

[0071] The planetary roller screw and its shaft are connected at their base and output ends, respectively, using angular contact ball bearings. The advantage of using angular contact ball bearings at both ends is that it avoids misalignment issues caused by machining and assembly errors. Furthermore, angular contact ball bearings can self-adjust their rotation direction. Placing two angular contact ball bearings back-to-back not only improves axial and radial load capacity but also prevents the main and auxiliary connecting rods from failing under torsional loads, while simultaneously enhancing their impact resistance.

[0072] An end cap force sensor is fixedly connected to the end of the planetary roller screw, which can monitor the output force of the planetary roller screw in real time.

[0073] The thigh frame also contains a wire harness support rod. This support rod not only secures the wire harness, preventing it from colliding with the planetary roller screw during movement and thus avoiding poor contact or damage, but it also enhances the support stiffness of the thigh frame, reducing compression deformation caused by lateral forces and improving the overall rigidity and positional control accuracy of the thigh frame.

[0074] The hip system is a three-degree-of-freedom system. The pitch degree of freedom is achieved by the reciprocating linear motion of the planetary roller screw, which drives the main and auxiliary connecting rods. In addition to the pitch degree of freedom, it also includes roll and yaw degrees of freedom. The following are the implementation methods and working principles of these two degrees of freedom: Implementation of roll degree of freedom: The roll degree of freedom is achieved by the roll joint module (3). The roll joint module is driven by a motor, which drives the yaw joint module (4) and the pitch base assembly to rotate around the roll axis, thereby realizing the roll motion of the hip. Working process and principle:

[0075] Motor drive: The roll joint module (3) has a built-in motor, which transmits the rotational motion to the quick-release connector (3-2) at the output end of the roll joint through a reducer and transmission mechanism. The control signal of the motor is received through the quick-release connector (3-1) at the input end of the roll joint, and the power and communication signals are transmitted to the yaw joint module (4) through the quick-release connector (3-2) at the output end of the roll joint.

[0076] Roll motion transmission: The quick-release connector (3-2) at the output end of the roll joint is connected to the yaw joint module (4) to transmit rotational motion to the yaw joint module. The yaw joint module (4) drives the pitch base assembly to rotate around the roll axis, thereby realizing the roll motion of the hip.

[0077] Motion control: By controlling the motor speed and direction of the roll joint module (3), the roll angle and speed of the hip can be precisely controlled. The roll joint module (3) has a built-in encoder that provides real-time feedback of roll angle information, enabling closed-loop control and improving motion accuracy.

[0078] Implementation of yaw freedom: The yaw freedom is realized by the yaw joint module (4). The yaw joint module is driven by a motor to rotate the pitch base assembly around the yaw axis, thereby realizing the yaw motion of the hip; the working process and principle are as follows:

[0079] Motor Drive: The yaw joint module (4) has a built-in motor, which transmits rotational motion to the quick-release connector (4-3) at the output end of the yaw joint through a reducer and transmission mechanism. The motor's control signal is received through the quick-release connector (4-2) at the input end of the yaw joint, and the power and communication signals are transmitted to the pitch base assembly through the quick-release connector (4-3) at the output end of the yaw joint. Yaw Motion Transmission: The quick-release connector (4-3) at the output end of the yaw joint connects to the pitch base assembly, transmitting rotational motion to the pitch base assembly. The pitch base assembly rotates around the yaw axis, thereby realizing the yaw motion of the hip. Motion Control: By controlling the motor speed and direction of the yaw joint module (4), the yaw angle and speed of the hip can be precisely controlled. The yaw joint module (4) has a built-in encoder that provides real-time feedback of yaw angle information, realizing closed-loop control and improving motion accuracy.

[0080] Three-degree-of-freedom collaborative work:

[0081] Pitch freedom: The output end joint bearing (22) of the planetary roller screw (9) drives the main drive shaft (33) to move, and the main drive shaft drives the main connecting rod (5) to rotate around the fixed point on the thigh skeleton; the main drive shaft simultaneously drives the auxiliary connecting rod (6) and the force sensor (7) to move, and the force sensor transmits the force to the pitch base (19) through the needle roller bearing (34), so that the pitch base can perform pitch motion around the axis of the pitch fastening shaft (24).

[0082] Roll freedom: The roll joint module (3) is driven by a motor to drive the yaw joint module (4) and the pitch base assembly to rotate around the roll axis, thereby realizing the roll motion of the hip.

[0083] Yaw freedom: The yaw joint module (4) is driven by a motor to rotate the pitch base assembly around the yaw axis, thereby realizing the yaw motion of the hip.

[0084] Coordinated control: By coordinating the control of the three degrees of freedom of pitch, roll and yaw, complex hip movements in three-dimensional space can be achieved; the control system adjusts the motion parameters of each degree of freedom in real time according to the task requirements to ensure the stability, accuracy and adaptability of hip movements.

[0085] The working principle of this invention to achieve three degrees of freedom motion:

[0086] 1. Pitch motion: The output end joint bearing 22 of the planetary roller screw 9 drives the main drive shaft 33 to move. The main drive shaft 33 drives the main connecting rod 5 to rotate around a fixed point on the thigh skeleton 1. The main drive shaft 33 simultaneously drives the auxiliary connecting rod 6 and the force sensor 7 to move. The force sensor 7 transmits the force to the pitch base 19 through the needle roller bearing 34, so that the pitch base 19 can move in pitch around the axis of the pitch fastening shaft 24.

[0087] 2. Rolling motion: The rolling joint module 3 achieves the rolling motion of the hip through a motor drive. The motor drives the quick-release connector 3-2 at the output end of the rolling joint to rotate through a reducer and transmission mechanism, thereby driving the yaw joint module 4 and the pitch base assembly to rotate around the rolling axis.

[0088] 3. Yaw Movement: The yaw joint module 4 achieves yaw movement of the hip through a motor drive. The motor drives the quick-release connector 4-3 at the output end of the yaw joint to rotate through a reducer and transmission mechanism, thereby driving the pitch base assembly to rotate around the yaw axis.

[0089] In this design, the angular contact ball bearing can be replaced with a deep groove ball bearing, and the planetary roller screw can be replaced with a push rod that can achieve linear reciprocating motion.

[0090] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A novel three-degree-of-freedom hip system for a humanoid robot, characterized by: The thigh skeleton serves as the load-bearing structure of the hip system; Main base assembly, used to secure the roll joint module; The roll joint module is locked to the main base by fastening screw A. The quick-release connector at the output end of the roll joint is connected to the yaw joint module to realize the transmission of power and communication signals. The yaw joint module is fixed to the yaw joint base by fastening screw C. The quick-release connector at the output end of the yaw joint is connected to the pitch base assembly to realize the transmission of power and communication signals. The pitch base assembly includes a pitch base, on the side of which two angular contact ball bearings A are placed. The outer rings of the two angular contact ball bearings A are fixedly mounted on the bearing mounting seats of the pitch base by an interference fit, and are positioned by a step at the bottom of the bearing mounting seats to restrict the axial movement of the outer rings of the angular contact ball bearings A. The pitch base is locked to the thigh frame on both sides by two pitch fastening shafts and several fastening screws F. Specifically, one end face of the pitch fastening shaft is in contact with the thigh frame, and the other end face is in contact with the end face of the inner ring of the angular contact ball bearing A. The large end face of the pitch fastening shaft is fixed to the thigh frame by several fastening screws F. The pitch base is connected to a force sensor fixed to the other end of the auxiliary connecting rod via a main support shaft. The planetary roller screw assembly includes a base end spherical bearing, an end cap force sensor, a planetary roller screw, and an output end spherical bearing. The base end spherical bearing is fixed to the thigh frame by a locking shaft and a hexagonal lock nut. The main link and the secondary link are connected. The other end of the main link is fixedly connected to the thigh skeleton, and the other end of the secondary link is connected to the pitch base through a force sensor. The other end of the force sensor is connected to the pitch base via the main support shaft. Specifically, a needle roller bearing is nested at the other end of the force sensor. The outer ring of this needle roller bearing is fixed by a retaining ring through the force sensor and the hole. The inner ring of the needle roller bearing is secured by the end faces of the main and auxiliary support shafts and locked in place by anti-loosening washers C and fastening screws E. The fastening screws E are directly locked onto the main support shaft, making installation simple and convenient. Both the main and auxiliary support shafts are fixed to the pitch base. The outer end face of the force sensor is restricted from axial movement by a PTFE pad B, and the axial movement is controlled by adjusting the thickness of the PTFE pad B. The rotational resistance of the force sensor is adjusted; the planetary roller screw assembly drives the main connecting rod and the auxiliary connecting rod through reciprocating linear motion; the roll joint module realizes the roll motion of the hip through motor drive; the yaw joint module realizes the yaw motion of the hip through motor drive; the planetary roller screw assembly includes a base end joint bearing, an end cap force sensor, a planetary roller screw, and an output end joint bearing. The base end joint bearing is fixed to the thigh skeleton by a locking shaft and a hexagonal anti-loosening nut. The output end joint bearing is connected to the main connecting rod and the auxiliary connecting rod through the main drive shaft and the auxiliary drive shaft; the force sensor is connected to the main support shaft through a needle roller bearing.

2. The three-degree-of-freedom hip system according to claim 1, characterized in that, The roll joint module includes a quick-release connector for the roll joint input end and a quick-release connector for the roll joint output end, which enables the rapid transmission of power and communication signals.

3. The three-degree-of-freedom hip system according to claim 1, characterized in that, The yaw joint module includes a yaw joint base, a quick-release connector for the yaw joint input end, and a quick-release connector for the yaw joint output end. The quick-release connector enables rapid transmission of power and communication signals, facilitating assembly and maintenance.

4. A method for realizing three-degree-of-freedom motion, the method being based on the system described in claim 1, characterized in that, Includes the following steps: Pitch motion: The output end joint bearing of the planetary roller screw drives the main drive shaft to move. The main drive shaft drives the main connecting rod to rotate around a fixed point on the thigh skeleton. The main drive shaft also drives the auxiliary connecting rod and the force sensor to move. The force sensor transmits the force to the pitch base through the needle roller bearing, so that the pitch base can move in pitch around the axis of the pitch fastening shaft. Roll motion: The roll joint module is driven by a motor, which drives the yaw joint module and the pitch base assembly to rotate around the roll axis to achieve the roll motion of the hip. Yaw motion: The yaw joint module is driven by a motor to rotate the pitch base assembly around the yaw axis, thereby realizing the yaw motion of the hip.

5. The method according to claim 4, characterized in that, The rolling motion is driven by the motor of the rolling joint module, which in turn drives the yaw joint module and the pitch base assembly to rotate around the rolling axis, thereby realizing the rolling motion of the hip.

6. The method according to claim 5, characterized in that, The yaw motion is driven by the motor of the yaw joint module, which drives the pitch base assembly to rotate around the yaw axis, thereby realizing the yaw motion of the hip.

7. A humanoid robot, characterized in that, Including the three-degree-of-freedom hip system as described in claim 1, it is suitable for industrial handling and rehabilitation training applications.

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