Humanoid robot leg structure based on planetary roller screw

Abstract

The invention discloses a humanoid robot leg structure based on a planetary roller screw, and aims to provide a mechanical structure scheme for converting rotational motion into linear motion, so that the adaptability and the motion stability of a robot in complex terrains can be improved. According to the structure, a planetary roller screw is adopted as a main transmission element, a screw nut is driven by a motor, high-precision push-pull motion is achieved, and leg joints of the robot are driven to move. Compared with a traditional gear, hydraulic or linear motor driving mode, the transmission mechanism has the advantages of being high in transmission efficiency, low in reverse clearance, low in energy consumption and excellent in torque transmission characteristic. By means of the structure, humanoid linear joint movement of the legs can be achieved, the robot can more stably complete complex actions such as walking, standing and jumping, meanwhile, the maintenance cost is reduced, and the system reliability is improved. The robot can be widely applied to the fields of humanoid robots, rescue robots, special operation robots and the like.

Description

Technical Field

[0001] The present invention relates to a robot leg structure of a biped humanoid robot, and specifically to a humanoid robot leg structure. Background Art

[0002] As an important part of a humanoid intelligent system, humanoid robots have broad application prospects in the fields of service, medical treatment, industry, rescue, etc. Among them, the structural design of the robot legs directly determines its motion ability, stability and energy consumption efficiency. The traditional driving methods for the legs of humanoid robots mainly include motor + gear transmission, hydraulic drive and linear motor drive, etc. These methods have their own advantages and disadvantages.

[0003] The motor + gear transmission method has a mature structure and high control precision, but there are problems such as large mechanical transmission clearance, low transmission efficiency and high noise. The hydraulic drive method has a large output force and fast dynamic response characteristics, but its system is complex, there is a risk of oil leakage, and the maintenance cost is high. The linear motor drive method has the characteristics of high response and high precision, but its cost is high, and the energy efficiency ratio in large load scenarios is not ideal.

[0004] In recent years, the planetary roller screw, as an efficient linear transmission device, has been applied in the global high-precision and high-tech fields such as aerospace, weaponry, and nuclear power due to its advantages of high load, impact resistance, small volume, high speed, etc., and has gradually attracted attention in the field of robot joint drive. The planetary roller screw generates line contact rolling friction through meshing rollers, greatly increasing the contact surface and force-bearing surface in the screw transmission process. Compared with the ball screw used for precision transmission in the past, on the premise of little loss of transmission efficiency, it also has the characteristics of high rotational speed, high load, high stiffness, high range lead, smaller volume, lower noise, and more convenient maintenance and disassembly. In addition, the planetary roller screw mechanism has a lower backlash compared with gear transmission, which helps to improve the control precision of the robot joints.

[0005] Based on the robot leg structure design of the planetary roller screw, combined with motor drive, high-precision position control and efficient power transmission can be achieved, while optimizing the energy efficiency ratio of the system and reducing the maintenance cost of the system. Therefore, exploring the application of the planetary roller screw in robot leg drive has important research value and application prospects. Based on this, the present invention proposes a humanoid robot leg structure based on the planetary roller screw, referring to Figure 1 、 2, when the biped robot walks, the hip joint power supply device rotates, driving the thigh link 2 to rotate; inside the sleeve 3, the power transmission device rotates, driving the lead screw roller nuts 13 and 18 to rotate, and then causing the lead screw 12 to perform a push-pull motion; during the lead screw push-pull motion, the bearings fixed by the sleeve bearing connection frame 7 and the push rod bearing frame 8 will rotate relative to the bracket; the lead screw 12's push-pull motion drives the calf link 11 to rotate; the calf part lead screw structure is the same. When the two lead screw structures move at the same speed, it drives the foot plate to pitch, and at the same time, the bearings fixed by the ankle joint longitudinal bearing frame 9 rotate relative to the bracket; when the two lead screw structures move in opposite directions, it drives the foot plate to roll, and the bearings fixed by the ankle joint transverse bearing frame 10 rotate relative to the bracket. The anti-radiation material shell 19 enables the humanoid robot to perform inspections in nuclear factories with strong radiation without damaging internal components. By changing the working mode of the motor, the transmission direction of the lead screw is changed, enabling the humanoid leg to achieve different motion purposes to adapt to complex terrains and task requirements. Summary of the Invention

[0006] The present invention proposes a humanoid robot leg structure based on planetary roller screws, a robot leg structure that can continuously and stably work in complex terrains and achieve multiple posture goals.

[0007] A humanoid robot leg structure based on planetary roller screws, which includes a hip joint motor frame 1, a thigh link 2, a lead screw sleeve 3, a joint bearing 4, a sleeve fixing part 5, a spherical bearing 6, a sleeve bearing connection frame 7, a push rod bearing frame 8, an ankle joint longitudinal bearing frame 9, an ankle joint transverse bearing frame 10, a calf link 11, a planetary roller screw 12, lead screw roller nuts 13, 18, a nut fixing sleeve 17, a motor housing 14, a thrust needle roller bearing 16, a motor base 15, and an anti-radiation material shell 19;

[0008] The thigh link 2 is connected to the output shaft of the power supply device through a bearing; the power transmission device is fixed to the motor frame 1; the lead screw sleeve 3 is connected to the thigh link 2 through the sleeve bearing connection frame 7 and a bearing; the thigh link 2 is connected to the calf link 11 through a joint bearing 4; the calf part lead screw structure is the same as that of the lead screw sleeve 3 and is fixed to the calf link 11 through the sleeve fixing part 5 and the spherical bearing 6. The bottom of the planetary roller screw 12 is connected to the foot plate through the spherical bearing 6; the lower end of the calf link 11 is fixed with the ankle joint longitudinal bearing frame 9 and a bearing; the ankle joint longitudinal bearing frame 9 is fixed to the ankle joint transverse bearing frame 10, and the lower end of the ankle joint transverse bearing frame 10 is connected to the foot plate;

[0009] The rollers of the planetary roller screw 12 roll in the thread grooves inside the screw roller nuts 13 and 18, and the push-pull movement of the screw is realized through the engagement of the threads; the planetary roller screw 12 is located inside the screw sleeve 3 and cooperates with the screw roller nuts 13 and 18. The nut fixing sleeve 17 is fixedly connected to the motor housing 14; a thrust needle roller bearing 16 is embedded between the motor base 15 and the motor housing 14; the motor base 15 is coaxially fixed with the screw roller nut 18, completing the main body assembly of the humanoid robot leg structure based on the planetary roller screw. The outside of the main body of the humanoid robot leg structure based on the planetary roller screw is covered by an anti-radiation material housing 19.

[0010] Furthermore, the power output device is composed of a motor, a gearbox, and an encoder. The motor, the gearbox, and the encoder are connected in sequence for power output; by changing the working mode of the motor, the transmission direction of the planetary roller screw 12 is changed, enabling the humanoid leg to achieve different movement purposes to adapt to complex terrains and mission requirements.

[0011] Further, when the humanoid robot walks, the hip joint power supply device rotates, driving the thigh link 2 to rotate; inside the sleeve 3, the power transmission device rotates, driving the lead screw roller nuts 13 and 18 to rotate, and then causing the planetary roller screw 12 to perform a push-pull motion; during the push-pull motion of the lead screw, the bearings fixed by the sleeve bearing connecting frame 7 and the push rod bearing frame 8 will rotate relative to the bracket; the push-pull motion of the planetary roller screw 12 drives the calf link 11 to rotate; in the calf part lead screw structure, when the two lead screw structures move at the same speed, it drives the foot plate to pitch, and at the same time the bearing fixed by the longitudinal bearing frame 9 of the ankle joint rotates relative to the bracket; when the two lead screw structures move in opposite directions, it drives the foot plate to roll, and the bearing fixed by the transverse bearing frame 10 of the ankle joint rotates relative to the bracket; when the power output device works, power is transmitted to the lead screw roller nuts 13 and 18 through the gearbox and encoder, and the rotation of the lead screw roller nuts 13 and 18 drives the planetary roller screw 12 to perform a push-pull motion; the push-pull motion of the planetary roller screw 12 is transmitted to the calf link 11 through the sleeve bearing connecting frame 7 and the push rod bearing frame 8, thus realizing the movement of the calf; when the two lead screw structures move at the same speed, the foot plate generates a pitching motion; when the two lead screw structures move in opposite directions, the foot plate generates a rolling motion; by changing the working mode of the power output device, the transmission direction of the lead screw is changed, enabling the legs of the humanoid robot to achieve different movement purposes to adapt to complex terrains and task requirements; through the control of the power output device, the planetary roller screw 12 can achieve different transmission directions and speed changes, making the legs of the humanoid robot highly flexible and adaptable in complex terrains such as walking, climbing slopes, and crossing obstacles; during walking, the legs adjust the push-pull motion of the lead screw to achieve different gaits and postures to adapt to different ground conditions; during the inspection task in a nuclear power plant, it is necessary to walk on narrow passages, stairs, and uneven ground; through the control of the power output device, the planetary roller screw 12 realizes the push-pull motion of the lead screw, enabling the legs to flexibly adjust the gait during walking; when the humanoid robot needs to cross a pipeline or an obstacle, the legs adjust the push-pull motion of the lead screw to achieve the pitching and rolling motions of the foot plate, thereby crossing the obstacle and ensuring the smooth progress of the inspection task; in the complex environment of a nuclear power plant, the humanoid robot needs to have the ability to avoid obstacles; through the efficient transmission of the planetary roller screw 12, the legs of the humanoid robot quickly adjust the posture when encountering an obstacle; when the humanoid robot detects an obstacle ahead, the legs cause the foot plate to generate a rolling motion through the push-pull motion of the lead screw, thereby changing the walking direction and avoiding the obstacle.

[0012] Furthermore, the anti-radiation material shell 19 enables the humanoid robot to conduct inspections in a nuclear power plant with strong radiation without damaging internal components.

[0013] The beneficial effects of the present invention are as follows:

[0014] By changing the working mode of the motor, the transmission direction of the lead screw is changed, enabling the humanoid leg to achieve different motion purposes to adapt to complex terrains and task requirements, and making full use of the control advantages of the planetary roller screw. Brief Description of the Drawings

[0015] Figure 1 It is a leg structure of a humanoid robot based on a planetary roller screw.

[0016] Figure 2 It is an external view of a leg structure of a humanoid robot based on a planetary roller screw.

[0017] Figure 3 It is the internal structure diagram of the lead screw sleeve. Detailed Implementation Manner

[0018] The present invention will be further described below in conjunction with the drawings and the detailed implementation manner.

[0019] As Figure 1 shown, a leg structure of a humanoid robot based on a planetary roller screw, characterized in that: the structure includes a hip joint motor bracket 1, a thigh connecting rod 2, a lead screw sleeve 3, a joint bearing 4, a sleeve fixing member 5, a spherical bearing 6, a sleeve bearing connecting bracket 7, a push rod bearing bracket 8, an ankle joint longitudinal bearing bracket 9, an ankle joint transverse bearing bracket 10, and a calf connecting rod 11.

[0020] As Figure 2 shown, the anti-radiation material shell 19 can enable the humanoid robot to perform inspections in nuclear factories with strong radiation without damaging internal components.

[0021] To understand the present invention more clearly and vividly, taking a hexapod robot as an example, the application of two modes to the robot will be described with reference to Figure 3 :

[0022] With reference to Figure 3 , the power transmission device rotates, driving the lead screw roller nuts 13 and 18 to rotate, and then causing the lead screw 12 to perform push-pull motions. By changing the working mode of the motor, the transmission direction of the lead screw is changed, enabling the humanoid leg to achieve different motion purposes to adapt to complex terrains and task requirements, and making full use of the control advantages of the planetary roller screw.

[0023] Embodiment

[0024] With reference to Figure 1 , 2, a humanoid robot leg structure based on a planetary roller screw, characterized in that: the structure includes a hip joint motor bracket 1, a thigh connecting rod 2, a screw sleeve 3, a joint bearing 4, a sleeve fixing part 5, a spherical bearing 6, a sleeve bearing connecting bracket 7, a push rod bearing bracket 8, an ankle joint longitudinal bearing bracket 9, an ankle joint transverse bearing bracket 10, a calf connecting rod 11, a screw 12, screw roller nuts 13, 18, a nut fixing sleeve 17, a motor housing 14, a thrust needle roller bearing 16, a motor base 15, and a radiation-resistant material housing 19; the thigh connecting rod 2 is connected to the output shaft of the power supply device through a bearing; the power transmission device is fixedly connected to the motor bracket 1; the screw sleeve 3 is connected to the thigh connecting rod 2 through the sleeve bearing connecting bracket 7 and a bearing; the thigh connecting rod 2 is connected to the calf connecting rod 11 through a bearing; the screw structure of the calf part is the same as that of the screw sleeve 3, and is fixed to the calf connecting rod 11 through the sleeve fixing part 5 and the spherical bearing, and the bottom of the screw is connected to the foot plate through the spherical bearing; the lower end of the calf connecting rod 11 is fixedly connected to the ankle joint longitudinal bearing bracket 9 and a bearing; the ankle joint longitudinal bearing bracket 9 is fixedly connected to the ankle joint transverse bearing bracket 10, and the lower end of the ankle joint transverse bearing bracket is connected to the foot plate.

[0025] The inner sides of the screw roller nuts 13, 18 are in threaded engagement with the outer side of the screw 12; the nut fixing sleeve 17 is fixedly connected to the motor housing 14; a thrust needle roller bearing 16 is embedded between the motor base 15 and the motor housing 14; the motor base 15 is coaxially fixed to the screw roller nut 18.

[0026] The power output device is composed of a motor, a gearbox, and an encoder, and the motor, the gearbox, and the encoder are connected in sequence for power output.

[0027] Finally, it should be noted that: the above embodiments are only used to illustrate the present invention and do not limit the technical solutions described in the present invention. Therefore, although this specification has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that the present invention can still be modified or equivalently replaced, and all technical solutions and their improvements that do not depart from the spirit and scope of the invention shall be covered by the scope of the claims of the present invention.

Claims

1. A humanoid robot leg structure based on a planetary roller screw, characterized in that: The structure comprises a hip joint motor frame (1), a thigh connecting rod (2), a lead screw sleeve (3), a joint bearing (4), a sleeve fixing part (5), a fisheye bearing (6), a sleeve bearing connecting frame (7), a push rod bearing frame (8), an ankle joint longitudinal bearing frame (9), an ankle joint transverse bearing frame (10), a calf connecting rod (11), a planetary roller screw (12), a lead screw roller nut (13, 18), a nut fixing sleeve (17), a motor housing (14), a thrust needle roller bearing (16), a motor base (15) and an anti-radiation material housing (19); The thigh connecting rod (2) is connected to the output shaft of the power supply device through a bearing; the power transmission device and the motor frame (1) are fixed to each other; the screw sleeve (3) is connected to the thigh connecting rod (2) through a sleeve bearing connecting frame (7) and a bearing; the thigh connecting rod (2) is connected to the shank connecting rod (11) through a joint bearing (4); the screw structure of the shank part is the same as the screw sleeve (3), and is fixed to the shank connecting rod (11) through a sleeve fixing member (5) and a fisheye bearing (6), and the bottom of the planetary roller screw (12) is connected to the foot plate through the fisheye bearing (6); the lower end of the shank connecting rod (11) is fixed to the ankle joint longitudinal bearing frame (9) and the bearing; the ankle joint longitudinal bearing frame (9) is fixed to the ankle joint transverse bearing frame (10), and the lower end of the ankle joint transverse bearing frame (10) is connected to the foot plate; The rollers of the planetary roller screw (12) roll in the thread grooves on the inner sides of the screw roller nuts (13, 18), and the push-pull movement of the screw is realized through the meshing of the threads; the planetary roller screw (12) is located inside the screw sleeve (3), cooperates with the screw roller nuts (13, 18), and is fixedly connected to the motor housing (14) through the nut fixing sleeve (17); a thrust needle bearing (16) is embedded between the motor base (15) and the motor housing (14); the motor base (15) and the screw roller nut (18) are coaxially fixed, and the main body assembly of the humanoid robot leg structure based on the planetary roller screw is completed, and the outer side of the main body of the humanoid robot leg structure based on the planetary roller screw is covered by an anti-radiation material shell (19).

2. The humanoid robot leg structure based on a planetary roller screw according to claim 1, characterized in that: The power output device is composed of a motor, a gear box, and an encoder, which are connected in sequence to output power; by changing the working mode of the motor, the transmission direction of the planetary roller screw (12) is changed, so that the humanoid leg can achieve different movement purposes to adapt to complex terrain and task requirements.

3. The humanoid robot leg structure based on a planetary roller screw according to claim 1, characterized in that: When the humanoid robot walks, the hip joint power supply device rotates, driving the thigh connecting rod (2) to rotate; inside the sleeve (3), the power transmission device rotates, driving the screw roller nut (13, 18) to rotate, thereby causing the planetary roller screw (12) to push and pull; during the push and pull movement of the screw, the bearings fixed by the sleeve bearing connecting frame (7) and the push rod bearing frame (8) will rotate relative to the bracket; the push and pull movement of the planetary roller screw (12) drives the calf connecting rod (11) to rotate; in the screw structure of the calf part, when the two screw structures move at the same speed, the foot plate is driven to pitch and at the same time, the bearing fixed by the ankle joint longitudinal bearing frame (9) rotates relative to the bracket; when the two screw structures When the two screw structures move at opposite speeds, the foot plate will roll, and the bearing fixed to the ankle joint transverse bearing frame (10) will rotate relative to the frame; when the power output device is working, the power is transmitted to the screw roller nut (13, 18) through the gear box and the encoder, and the rotation of the screw roller nut (13, 18) drives the planetary roller screw (12) to push and pull; the push and pull movement of the planetary roller screw (12) is transmitted to the calf connecting rod (11) through the sleeve bearing connecting frame (7) and the push rod bearing frame (8), thereby realizing the movement of the calf; when the two screw structures move at the same speed, the foot plate will produce a pitching movement; when the two screw structures move at opposite speeds, the foot plate will produce a rolling movement; by changing The working mode of the power output device is changed to realize the change of the transmission direction of the screw, so that the legs of the humanoid robot can achieve different movement purposes to adapt to complex terrain and task requirements; through the control of the power output device, the planetary roller screw (12) can realize different transmission directions and speed changes, so that the legs of the humanoid robot have high flexibility and adaptability in walking, climbing, and crossing obstacles in complex terrain; during walking, the legs can achieve different gaits and postures by adjusting the push-pull movement of the screw to adapt to different ground conditions; in the inspection task of the nuclear plant, it is necessary to walk on narrow passages, stairs and uneven ground; through the control of the power output device The planetary roller screw (12) realizes the push-pull movement of the screw, so that the legs can flexibly adjust their gait during walking; when the humanoid robot needs to cross a pipe or an obstacle, the legs adjust the push-pull movement of the screw to realize the pitch and roll movement of the foot, thereby crossing the obstacle and ensuring the smooth progress of the inspection task; in the complex environment of a nuclear plant, the humanoid robot needs to have the ability to avoid obstacles; through the efficient transmission of the planetary roller screw (12), the legs of the humanoid robot can quickly adjust their posture when encountering an obstacle; when the humanoid robot detects an obstacle in front of it, the legs cause the foot to produce a roll movement through the push-pull movement of the screw, thereby changing the walking direction and avoiding the obstacle.

4. The humanoid robot leg structure based on a planetary roller screw according to claim 1, characterized in that: The radiation-resistant material shell (19) enables the humanoid robot to conduct inspections in nuclear plants with strong radiation without damaging internal components.

Images