A knee joint structure with dynamically adjustable speed ratio for high explosive jumping motion

Abstract

The present invention provides a knee joint structure with a high-explosive jumping motion speed ratio that is dynamically adjustable, comprising a rotatably connected thigh and calf, and a push rod, wherein the push rod head end is connected to the thigh, and the push rod tail end is connected to the calf; the push rod comprises a driving mechanism, a connecting rod, a force sensor, and an axis system assembly, wherein the driving mechanism is connected to one end of the connecting rod, and a force sensor is installed at the other end of the connecting rod, and the force sensor is connected to the axis system assembly, the driving mechanism is connected to a connecting block of the thigh, and the connecting block can move along a guide rail under the drive of a servo motor, and the axis system assembly is connected to a slider of the calf, and the slider can move along a track under the drive of a servo motor. In the present invention, the head and tail ends of the push rod can slide as needed, effectively adjusting the joint output torque, and then adjusting the joint output speed, while effectively resisting the large impact during take-off and landing during jumping.

Description

Technical Field

[0001] The invention relates to the field of humanoid robots, and in particular to a knee joint structure with a high-explosive jumping motion speed ratio that is dynamically adjustable. Background Art

[0002] In recent years, due to the rapid development of science and technology, many countries have increased their investment in robot research. Humanoid robots are the commanding heights of intelligent robot technology. At the same time, with their strong adaptability and flexibility, they have practical application significance in future national defense science and technology, deep-sea exploration, fire prevention and disaster relief and other harsh environments.

[0003] In view of the increasingly higher requirements for the environmental adaptability of robots, the ability to jump is a necessary condition for humanoid robots to adapt to non-structured environments. Jumping movement itself requires the joints to have strong explosive power. When the joint driving torque is constant, changing the transmission speed ratio of the joint is an effective means to improve the robot's jumping ability.

[0004] Although the existing technology can change the reduction ratio of the joint and adjust the speed and output torque to a certain extent, because the joint position is fixed, the speed ratio adjustment ability is limited, which restricts the explosive power of the robot when jumping. Summary of the invention

[0005] In view of the shortcomings in the prior art, the present invention provides a knee joint structure with dynamically adjustable speed ratio for high-explosive jumping motion, which dynamically adjusts the joint output torque during the jumping motion to meet the requirements of large torque in the initial stage of take-off and high speed in the later stage of take-off; at the same time, the knee joint can effectively resist the impact force during take-off and landing during the joint jumping motion.

[0006] The present invention achieves the above technical objectives through the following technical means.

[0007] A high-explosive jumping motion speed ratio dynamically adjustable knee joint structure, comprising a rotatably connected thigh and calf, and a push rod connected to the thigh at the head end, and the rear end of the push rod connected to the calf;

[0008] The push rod includes a driving mechanism, a connecting rod, a force sensor and a shaft system assembly, wherein the driving mechanism is connected to one end of the connecting rod, a force sensor is installed at the other end of the connecting rod, and the force sensor is connected to the shaft system assembly;

[0009] The shaft system assembly is connected to a slider of the calf, and the slider can move along the track;

[0010] The driving mechanism is connected to a connection block of the thigh, and the connection block can move along a guide rail.

[0011] According to a further technical solution, the thigh and the calf are connected via a connecting shaft.

[0012] According to a further technical solution, the driving mechanism includes a motor and a lead screw three connected to the motor, and a nut of the lead screw three is connected to a connecting rod.

[0013] A further technical solution is that the connecting rod includes a connecting rod one and a connecting rod two which are connected in sequence, and a limiting rubber pad is provided at the connection between the connecting rod one and the connecting rod two, the end of the connecting rod one away from the connecting rod two is connected to the nut of the lead screw three, and the end of the connecting rod two away from the connecting rod one is installed with a force sensor.

[0014] A further technical solution is that a sleeve is installed on the motor, the sleeve is located outside the screw three, and the nut connecting end of the connecting rod one and the screw three is also located in the sleeve, and a rubber pad is provided between the connecting rod one and the sleeve.

[0015] According to a further technical solution, the shaft system assembly includes a support member, a shaft and a bearing, the support member is fixed to the shaft, both ends of the shaft are fixed to L-shaped supports through bearings, and the L-shaped support is connected to the slider.

[0016] A further technical solution is that the track is installed on both sides of the bottom of the motor support plate 2, and the servo motor 2 is installed on the upper part of the motor support plate 2. The servo motor 2 is connected to one end of the lead screw 2, and the other end of the lead screw 2 is supported on a connecting seat, and the connecting seat is fixed on the upper part of the slider; a grating ruler 2 is provided on the track.

[0017] According to a further technical solution, two limit blocks are provided at both ends of the track.

[0018] A further technical solution is that the motor is installed in the hole opened in the push rod support seat through the flange, and the push rod support seat is installed at the bottom of the connecting block; the guide rail is installed on both sides of the bottom of the motor support plate, and a servo motor is installed on the upper part of the motor support plate, the servo motor is connected to one end of the lead screw, and the other end of the lead screw is supported on the upper part of the connecting block; a grating ruler is provided at the lower part of the guide rail.

[0019] According to a further technical solution, both ends of the guide rail are connected to limit blocks 1.

[0020] The beneficial effects of the present invention are as follows: the knee joint structure of the present invention is respectively installed with servo motors on the thigh and thigh, the servo motor is connected to the lead screw through a coupling, the lead screw on the thigh is supported on a connecting block, the connecting block can move along the guide rail, the lead screw on the calf is supported on a connecting seat, the connecting seat is fixed on a slider, and the slider can translate on the track; a push rod support seat is installed at the bottom of the connecting block, the push rod support seat is connected to the motor at the head end of the push rod through a flange, the tail end of the push rod is installed at the lower part of the slider, and the support member is connected through an L-shaped support, and the support member and the shaft form a shaft system assembly; the motor of the push rod is connected to a lead screw, a connecting rod 1 is connected to the lead screw, the tail end of the connecting rod 1 is connected to a connecting rod 2, a force sensor is installed on the connecting rod 2, and a support member is connected to the force sensor; in the present invention, since the slider can move along the track and the connecting block can move along the guide rail, the output torque of the knee joint is dynamically adjustable, and the structure can change the speed ratio and speed of the knee joint; on the other hand, the lead screw itself has the function of resisting reverse impact, and can effectively resist the large impact during take-off and landing during jumping. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of the knee joint with dynamically adjustable speed ratio for high explosive jumping motion according to the present invention;

[0022] Figure 2 This is a schematic diagram of the thigh structure of the present invention;

[0023] Figure 3 This is a schematic diagram of the calf structure of the present invention;

[0024] Figure 4 This is a schematic diagram of the push rod structure of the present invention;

[0025] Figure 5 This is a schematic diagram of the structure of the push rod head end of the present invention;

[0026] Figure 6 This is a schematic diagram of the end structure of the push rod member of the present invention;

[0027] Figure 7 It is a model principle diagram of the physical quantities of the knee joint structure of the present invention;

[0028] In the figure: 1-thigh, 2-push rod, 3-connecting shaft, 4-calf, 5-grating ruler one, 6-screw one, 7-connecting block, 8-coupling one, 9-motor support plate one, 10-servo motor one, 11-limit block one, 12-guide rail, 13-push rod support seat, 14-connecting seat, 15-slider, 16-track, 17-grating ruler two, 18-screw two, 19-coupling two, 20-servo motor two, 21-limit block two, 22-motor support plate two, 23-motor, 24-coupling three, 25-screw three, 26-sleeve, 27-connecting rod one, 28-rubber pad, 29-limit rubber pad, 30-connecting rod two, 31-force sensor, 32-support, 33-flange, 34-shaft, 35-bearing, 36-L-type support. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

[0030] like Figure 1 As shown, the present invention provides a knee joint structure with a dynamically adjustable speed ratio for high explosive jumping motion, comprising a thigh 1, a connecting shaft 3 and a calf 4. The thigh 1 and the calf 4 are connected by the connecting shaft 3 to achieve relative rotation between the thigh 1 and the calf 4. A push rod 2 is provided between the thigh 1 and the calf 4.

[0031] like Figure 2 As shown, the thigh 1 is composed of a grating ruler 5, a lead screw 6, a connecting block 7, a coupling 8, a motor support plate 9, a servo motor 10, a limit block 11, a guide rail 12 and a push rod support seat 13; a servo motor 10 is installed on the upper part of the motor support plate 9, and the output shaft of the servo motor 10 is connected to one end of the lead screw 6 through a coupling 8, and the other end of the lead screw 6 is supported on the upper part of the connecting block 7; guide rails 12 are respectively installed on both sides of the bottom of the motor support plate 9, and both ends of the guide rails 12 are connected to the limit blocks 11; the lower end of the connecting block 7 can move along the guide rail 12, and a push rod support seat 13 is installed at the bottom of the connecting block 7, and the head end of the push rod 2 is installed on the push rod support seat 13; the grating ruler 5 is arranged at the lower part of the guide rail 12, which is used to measure the translation distance of the head end of the push rod 2.

[0032] like Figure 3As shown, the shank 4 is composed of a grating ruler 17, a lead screw 18, a connecting seat 14, a coupling 19, a servo motor 20, a limit block 21, a slider 15, a track 16 and a motor support plate 22. The servo motor 20 is installed on the upper part of the motor support plate 22. The output shaft of the servo motor 20 is connected to one end of the lead screw 18 through the coupling 19. The other end of the lead screw 18 is supported on the connecting seat 14, and the connecting seat 14 is fixed on the upper part of the slider 15; the tracks 16 are installed on both sides of the bottom of the motor support plate 22, and the slider 15 can translate on the track 16, and limit blocks 21 are provided at both ends of the track 16; the grating ruler 17 is set on the track 16; the tail end of the push rod 2 is installed at the lower part of the slider 15 for measuring the translation distance of the tail end of the push rod 2.

[0033] like Figure 4 As shown, the push rod 2 is composed of a motor 23, a coupling 24, a screw 25, a sleeve 26, a connecting rod 1 27, a rubber pad 28, a limit rubber pad 29, a connecting rod 2 30, a force sensor 31, and a support 32; the motor 23 is connected to one end of the screw 3 25 through the coupling 3 24, and the rotational motion of the motor 23 is converted into a translational motion, providing power for the thigh 1 and the calf 4 to jump; the nut of the screw 3 25 is connected to one end of the connecting rod 1 27 through a screw, and the connecting rod 1 27 and the screw 3 25 are screwed together. One end of the female connection and the lead screw 3 25 are located inside the sleeve 26, which is mounted on the motor 23. The sleeve 26 provides guidance and support for the translational movement of the connecting rod 1 27; a rubber pad 28 is provided between the connecting rod 1 27 and the sleeve 26; the other end of the connecting rod 1 27 is connected to one end of the connecting rod 2 30 by screws, and the other end of the connecting rod 2 30 is installed with a force sensor 31, which is used to detect the output force of the push rod 2, and a support member 32 is connected to the force sensor 31 by screws. A limit rubber pad 29 is provided at the connection between the connecting rod 1 27 and the connecting rod 2 30.

[0034] like Figure 5 As shown, the motor 23 is connected to one end of the flange 33 by screws, and the other end of the flange 33 is inserted into the hole opened in the push rod support seat 13, so that the motor 23, the flange 33, and the push rod support seat 13 are connected, so that the head end of the push rod 2 can be translated along the guide rail 12 under the drive of the connecting block 7.

[0035] like Figure 6 As shown, the slider 15 is connected to the L-shaped support 36 by screws. Since the slider 15 can move on the track 16, the end of the push rod 2 can also move on the track 16. The support member 32 is fixed to the shaft 34, and the two ends of the shaft 34 are respectively fixed to the L-shaped support 36 through bearings 35. The support member 32, the shaft 34, and the bearing 35 constitute a shaft system assembly, so that the end of the push rod 2 can rotate around the center hole of the L-shaped support 36.

[0036] Figure 7To simulate the relationship between the joint torque and the position of the two ends of the push rod 2 during jumping, point P is the center of the knee joint (the center point of the connecting shaft 3), point M is the center of the support at the head end of the push rod 2, and point N is the center of the slider 15 at the end of the push rod 2. Points P, M, and N are connected to form a triangle, and the relationship between the torque of the knee joint and the position of the two ends of the push rod 2 can be deduced; according to formula (1) and combined with Figure 7 , find that the moment T of the knee joint is related to h po (i.e. the vertical distance from the connecting axis 3 to the push rod 2). During the leg take-off process, the calf 4 rotates around the center point D of the ankle joint, and the point P moves to the point P'; the thigh 1 rotates around the point P, and the head end of the push rod 2 moves along the guide rail 12, and the center of support of the head end of the push rod 2 moves from the point M to the point M'; the position of the end of the push rod 2 moves from the point N to the point N' due to the translation and rotation; the angle θ between the thigh 1 and the calf 4 increases, resulting in h po It gradually decreases, causing the output torque T of the knee joint to gradually decrease.

[0037]

[0038] Among them: A is the distance from the center point P of the knee joint to the support center of the front end of the push rod 2, which is the independent variable. When the front end of the push rod 2 moves, the independent variable A is calculated according to the measurement result of the grating ruler 15; B is the distance from the center point P of the knee joint to the center of the slider 15 at the end of the push rod, which is the independent variable. When the end of the push rod 2 moves, the independent variable B is calculated according to the measurement result of the grating ruler 17; C is the length of the push rod 2; F is the output force of the push rod 2, which can be measured by the force sensor 31 and is a known quantity; T is the output torque of the knee joint, which is a variable; G is the total weight of the thigh 1, which is a known quantity; iA is the distance from the center of mass of the thigh to the center point P of the knee joint, which is a known quantity; β is the angle between the thigh 1 and the push rod 2, and γ is the angle between the calf 4 and the push rod 2.

[0039] The working principle of the knee joint structure with high explosive jumping motion speed ratio dynamically adjustable is as follows: the motor 23 rotates to generate instantaneous output of large torque, which drives the lead screw 3 25 to rotate through the coupling 24. Under the action of the nut pair of the lead screw 3 25, the connecting rod 1 27 moves along the sleeve 26, thereby making the connecting rod 2 30, the force sensor 31, and the support 32 move together. When the servo motor 10 starts to work, through the connection of the coupling 1 8, the lead screw 1 6, the connecting block 7, the push rod support seat 13, and the flange 33, the head end of the push rod 2 can move horizontally on the guide rail 12, that is, Figure 7 The displacement A value can be changed continuously; when the servo motor 20 starts to work, through the connection of the coupling 2 19, the screw 2 18, the connecting seat 14, the slider 15, the shaft 34, the bearing 35, and the L-shaped support 36, the end of the push rod 2 can be arbitrarily translated and positioned on the track 16, that is, Figure 7 The displacement B value can change continuously. According to formula (1), the change of displacement A and B values ​​causes the angle θ to change, thereby changing the output torque T value and speed ratio of the knee joint.

[0040] The embodiments are preferred implementations of the present invention, but the present invention is not limited to the above-mentioned implementations. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essential content of the present invention belong to the protection scope of the present invention.

Claims

1. A knee joint structure with dynamically adjustable speed ratio for high-explosive jumping motion, characterized in that: It comprises a thigh (1) and a calf (4) which are rotatably connected, and a push rod (2) whose head end is connected to the thigh (1), and whose tail end is connected to the calf (4); The thigh (1) comprises a lead screw (6), a connecting block (7), a motor support plate (9), a servo motor (10), a guide rail (12) and a push rod support seat (13); a servo motor (10) is installed on the upper part of the motor support plate (9), the output shaft of the servo motor (10) is connected to one end of the lead screw (6), and the other end of the lead screw (6) is supported on the upper part of the connecting block (7); guide rails (12) are installed on both sides of the motor support plate (9), the lower end of the connecting block (7) can move along the guide rails (12), and a push rod support seat (13) is installed at the bottom of the connecting block (7), and the head end of the push rod (2) is installed on the push rod support seat (13); a grating ruler (5) is provided at the lower part of the guide rail (12); The lower leg (4) comprises a second lead screw (18), a connecting seat (14), a second servo motor (20), a slider (15), a track (16) and a second motor support plate (22); the second servo motor (20) is installed on the upper part of the second motor support plate (22), the output shaft of the second servo motor (20) is connected to one end of the second lead screw (18), the other end of the second lead screw (18) is supported on the connecting seat (14), and the connecting seat (14) is fixed on the upper part of the slider (15); the tracks (16) are installed on both sides of the second motor support plate (22), and the slider (15) can translate on the tracks (16); the tail end of the push rod (2) is installed on the lower part of the slider (15); and the track (16) is provided with a second grating ruler (17); The push rod (2) comprises a driving mechanism, a connecting rod, a force sensor (31) and a shaft system assembly, wherein the driving mechanism is connected to one end of the connecting rod, the force sensor (31) is installed at the other end of the connecting rod, and the force sensor (31) is connected to the shaft system assembly; The shaft system assembly is connected to a slider (15) of the lower leg (4), and the slider (15) can move along a track (16); The driving mechanism is connected to a connecting block (7) of the thigh (1), and the connecting block (7) can move along a guide rail (12); The driving mechanism comprises a motor (23) and a lead screw three (25) connected to the motor (23), and a nut of the lead screw three (25) is connected to a connecting rod; the connecting rod comprises a connecting rod one (27) and a connecting rod two (30) which are connected in sequence, and a limiting rubber pad (29) is provided at the connection between the connecting rod one (27) and the connecting rod two (30), an end of the connecting rod one (27) away from the connecting rod two (30) is connected to the nut of the lead screw three (25), and an end of the connecting rod two (30) away from the connecting rod one (27) is installed with a force sensor (31); The shaft system assembly comprises a support member (32), a shaft (34) and a bearing (35); the support member (32) is fixed to the shaft (34); both ends of the shaft (34) are respectively fixed to L-shaped supports (36) through bearings (35); and the L-shaped supports (36) are connected to the slider (15); The output torque T of the knee joint structure is: Wherein, F is the explosive output force of the push rod (2), A is the distance from the center point P of the knee joint to the support center of the front end of the push rod (2), B is the distance from the center point P of the knee joint to the center of the slider (15) at the end of the push rod, C is the length of the push rod (2), G is the total weight of the thigh (1), iA is the distance from the center of mass of the thigh to the center point P of the knee joint, β is the angle between the thigh (1) and the push rod (2), γ is the angle between the calf (4) and the push rod (2), and h is the angle between the lower leg (4) and the push rod (2). po is the vertical distance from the connecting shaft to the push rod (2).

2. The knee joint structure with dynamically adjustable speed ratio for high explosive jumping motion according to claim 1, characterized in that: The thigh (1) and the calf (4) are connected via a connecting shaft (3).

3. The knee joint structure with dynamically adjustable speed ratio for high explosive jumping motion according to claim 1, characterized in that: A sleeve (26) is installed on the motor (23), and the sleeve (26) is located outside the lead screw three (25), and the nut connecting end of the connecting rod one (27) and the lead screw three (25) is also located in the sleeve (26), and a rubber pad (28) is provided between the connecting rod one (27) and the sleeve (26).

4. The knee joint structure with dynamically adjustable speed ratio for high explosive jumping motion according to claim 1, characterized in that: Limit blocks 2 (21) are provided at both ends of the track (16).

5. The knee joint structure with dynamically adjustable speed ratio for high explosive jumping motion according to claim 1, characterized in that: Both ends of the guide rail (12) are connected to a limiting block (11).

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