Biped robot and linear actuator applied to biped robot

Abstract

The utility model discloses a biped robot and an applied linear actuator thereof, the biped robot comprises a main body connecting part and leg parts arranged on the two sides of the main body connecting part, the leg parts comprise thigh parts, shank parts, sole components and connecting rod components used for connection which are connected in sequence, and the thigh parts, the shank parts, the sole components and the connecting rod components are arranged on the two sides of the main body connecting part; the thigh part comprises a thigh rotating joint, a thigh lifting linear joint, a shank bending linear joint and a thigh supporting plate, the thigh lifting linear joint and the shank bending linear joint are linear actuators and are oppositely arranged, and the two ends of the thigh lifting linear joint and the two ends of the shank bending linear joint are rotationally installed; the shank part comprises an ankle linear joint and a shank supporting plate, the upper end of the ankle linear joint is rotatably connected with the shank supporting plate, and the lower end of the ankle linear joint is connected with the sole assembly. The utility model has the beneficial effects that the loading capacity of the biped robot is improved, and the requirements of heavy load, high response speed and high precision of the biped robot can be met.

Description

TECHNICAL FIELD

[0001] The utility model relates to robot technical field, specifically relates to a biped robot and its application's linear actuator. BACKGROUND

[0002] Biped robot is a kind of bionic robot, can realize the biped walking and related action of robot, and biped robot is generally divided into thigh joint rotary motion, small leg joint rotary motion, ankle joint pitch motion and ankle joint's turnover motion, and traditional biped robot all adopts rotary joint to realize above-mentioned motion;For full-size biped robot or weight-bearing type biped robot using rotary joint, to ensure that enough torque is provided, the joint motor of thigh position is very big, influence the anthropomorphism and aesthetic property of whole machine, by contrast, adopt linear joint, can well utilize the space of thigh position, hide linear actuator in the thigh contour, and enough thrust can be provided, so that the biped robot has enough load capacity.

[0003] But adopting linear actuator also has the following disadvantages: linear actuator is the joint that rotary motion is converted into linear motion, and most are open-loop or semi-closed loop control, cannot eliminate the transmission error existing in linear motion end, or adopts closed loop control, needs to increase linear displacement sensor to measure the displacement of linear motion end, but the cost is higher and the volume is larger;And for the biped robot of application linear actuator, for real-time position posture, the data that control end can read only has motor end encoder's rotation angle data, then needs to convert the push distance of linear actuator, and the push distance of linear actuator is converted into the rotation angle of end joint through four-bar linkage structure, calculates the final rotation angle posture of joint, and the calculation amount is large in the process, and the calculation error is large. UTILITY MODEL CONTENTS

[0004] To solve the above technical problems, the utility model provides a kind of biped robot and its application's linear actuator, can realize the closed loop control of the speed of double encoder of biped robot, position, with load, high motion precision, long life, small volume etc.

[0005] Specifically, the utility model discloses a biped robot, include: main body connecting portion and set up in the leg of main body connecting portion both sides, the leg includes the thigh department, shank department, sole assembly and be used for connecting connecting rod assembly that connect gradually, the thigh department includes: thigh rotary joint, thigh straight line joint of lifting leg, shank bending straight line joint and thigh support plate, thigh straight line joint of lifting leg and shank bending straight line joint are all straight line actuators, and are set reversely, and both ends of thigh straight line joint of lifting leg are rotatably installed with both ends of shank bending straight line joint, the shank department includes ankle straight line joint, shank support plate, and ankle straight line joint upper end is rotatably connected with shank support plate, and lower end is connected with sole assembly.

[0006] The beneficial effects of the above technical scheme are that the load capacity of the biped robot is improved, and the requirements of large load, high response speed and high precision of the biped robot can be met.

[0007] Further, the connecting rod assembly includes a connecting rod one and a connecting rod two for connecting the thigh rotary joint, the thigh straight line joint of lifting leg and the thigh support plate, and further includes a connecting shaft for connecting the thigh support plate and the thigh rotary joint, and the connecting shaft is provided with a straight line joint encoder one.

[0008] The beneficial effects of the above technical scheme are that the straight line joint encoder one can accurately sense the rotation angle and speed data of the thigh support plate, reduce transmission error, form a closed-loop control with the encoder in the straight line actuator, and improve the operation control accuracy of the whole leg.

[0009] Further, the connecting rod assembly further includes a connecting rod three and a connecting rod four for connecting the thigh and the shank, the connecting rod three and the connecting rod four are connected through a pin shaft one, the thigh support plate and the shank support plate are further connected through a pin shaft two, and the pin shaft two is provided with a straight line joint encoder two.

[0010] Further, the connecting rod three includes a first connecting portion and a second connecting portion symmetrically arranged and extending to the side surface, the second connecting portion is provided with a connecting hole for the pin shaft one to pass through, the connecting rod four is provided with a lug connected with the pin shaft one, and the other end of the connecting rod four is connected with the shank support plate.

[0011] The beneficial effects of the above technical scheme are that the connecting rod three and the connecting rod four are connected with the thigh support plate and the shank support plate, the stress structure is optimized, and the transmission of the thigh and the shank is more accurate.

[0012] Further, the ankle revolute joint comprises an ankle revolute joint one and an ankle revolute joint two arranged side by side, one end of which is rotatably connected with the lower leg support plate, and the other end is rotatably connected with the foot sole assembly, a cross shaft is arranged at the lower end of the lower leg support plate and connected with the foot sole assembly, and an ankle linear encoder three and an ankle linear encoder four are arranged on the cross shaft.

[0013] The ankle revolute joint arranged side by side can realize the front and rear pitching action of the foot sole assembly when being pushed out or recovered, and can realize the left and right rolling action of the foot sole assembly when being differentially moved, so that the movement of the robot is more smooth.

[0014] Further, the thigh revolute joint comprises a thigh revolute joint one and a thigh revolute joint two, and the rotation axes of the thigh revolute joint one and the thigh revolute joint two are perpendicular.

[0015] The arrangement of the two revolute joints makes the leg have multiple degrees of freedom in multiple directions, meeting the use needs.

[0016] Further, the thigh support plates are symmetrically arranged, and the thigh lifting revolute joint and the lower leg bending revolute joint are located between the thigh support plates.

[0017] The symmetrically arranged thigh support plates play a supporting and protecting role, and the leg is more stable.

[0018] Further, the application further discloses a linear actuator applied to the biped robot.

[0019] The linear actuator has the characteristics of large load, high movement precision, long service life and small size, and can meet the requirements of the biped robot in large load, high response speed and high precision.

[0020] Further, the two sides of the shell are provided with a connecting seat one and a connecting seat two, the connecting seat one is connected with the shell through a sensor, and the connecting seat two is connected with the extending end of the output shaft.

[0021] The arrangement of the two connecting seats facilitates connection, force sensors are arranged outside the linear actuator to realize force / torque closed-loop control, the three loops (speed, position and force) of the system are realized as a whole, and the precision is improved.

[0022] Further, the screw nut is provided with bearings on both sides, the shell is provided with sealing covers at both ends, and the sealing covers are provided with sealing assemblies.

[0023] The beneficial effects of the above technical solution are that the sealing assemblies can make the linear actuator have good dustproof and waterproof performance, and can meet the needs of more application scenarios with higher protection requirements. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced.

[0025] Figure 1 is a schematic diagram of the overall structure of the biped robot of the present application

[0026] Figure 2 is an enlarged view of A of the present application

[0027] Figure 3 is a side view of the biped robot of the present application

[0028] Figure 4 is a rear view of the biped robot of the present application

[0029] Figure 5 is an exploded view of the leg of the present application

[0030] Figure 6 is a schematic diagram of the connecting rod of the present application

[0031] Figure 7 is a schematic diagram of the connecting rod of the present application

[0032] Figure 8 is a schematic diagram of the cross shaft structure of the present application

[0033] Figure 9 is a sectional view of the linear actuator of the present application

[0034] The reference signs involved in the drawings are as follows:

[0035] Body connecting part 1; thigh part 2; thigh rotation joint 21; thigh rotation joint one 211; thigh rotation joint two 212; thigh lifting linear joint 22; calf bending linear joint 23; thigh support plate 24; thigh adapter 25; calf part 3; ankle linear joint 31; ankle linear joint one 311; ankle linear joint two 312; calf support plate 32; cross shaft 33; foot sole assembly 4; connecting rod one 51; connecting rod two 52; connecting shaft 53; connecting rod three 54; pin shaft one 541; pin shaft two 542; first connecting part 543; second connecting part 544; connecting rod four 55; lug 551; linear joint encoder one 61; linear joint encoder two 62; ankle linear encoder three 63; ankle linear encoder four 64; shell 7; motor 71; stator 711; rotor 712; sealing cover 72; encoder 73; output shaft 74; screw nut 75; connecting seat one 76; connecting seat two 77; sensor 78. DETAILED DESCRIPTION

[0036] The utility model will be further explained in detail in connection with the drawings.

[0037] As Figures 1-5 The utility model discloses a biped robot, include: body connecting part 1 and the leg part of setting at the both sides of body connecting part 1, and the leg part is at the left side of body connecting part 1, and the right side is set up symmetrically, the leg part includes the thigh part 2, calf part 3, foot sole assembly 4 and the connecting rod assembly for connecting in proper order, the thigh part 2 includes: thigh rotation joint 21, thigh lifting linear joint 22, calf bending linear joint 23 and thigh support plate 24, the thigh lifting linear joint 22 and calf bending linear joint 23 are all linear actuators, and are set up reversely, both ends of thigh lifting linear joint 22 and both ends of calf bending linear joint 23 are rotatably installed, the calf part 3 includes ankle linear joint 31, calf support plate 32, and the upper end of ankle linear joint 31 is rotatably connected with calf support plate 32, and the lower end is connected with foot sole assembly 4. Ankle linear joint 31 is also linear actuator.

[0038] In some embodiments, the connecting rod assembly includes connecting rod 1 51, connecting rod 2 52, and connecting shaft 53, which are used to connect the thigh rotary joint 21, the thigh leg-lifting linear joint 22, and the thigh support plate 24. The connecting shaft 53 is provided with a linear joint encoder 1 61. The connecting shaft 53 connects the thigh adapter 25 and the thigh support plates 24 on both sides. The thigh rotary joint 21 is rotationally connected to connecting rod 1 51 through the thigh adapter 25. The thigh adapter 25 is fixedly connected to the thigh rotary joint 21 and rotates under the drive of the thigh rotary joint 21. The output end of the thigh leg-lifting linear joint 22 is rotationally connected to connecting rod 1 51, and the other end of connecting rod 1 51 is rotationally connected to the thigh adapter 25. Connecting rod 1 51 and connecting rod 2 52 are relatively rotationally connected, and one end of connecting rod 2 52 is rotationally connected to the thigh support plate 24. When the screw shaft of the thigh leg-lifting linear joint 22 is pushed out, the entire thigh can be lifted.

[0039] In some embodiments, the connecting rod assembly further includes a connecting rod 3 54 and a connecting rod 4 55 for connecting the thigh portion 2 and the calf portion 3. Figures 6-7 As shown), connecting rod three 54 and connecting rod four 55 are connected by pin shaft one 541, and the thigh support plate 24 and the calf support plate 32 are also connected by pin shaft two 542. Pin shaft two 542 is provided with linear joint encoder two 62. The upper end of connecting rod one 51 is rotatably connected to the thigh support plate 24, and the lower end of connecting rod four 55 is connected to the calf support plate 32. One end of the calf bending linear joint 23 is rotatably connected to the thigh support plate 24, and the output end of the calf bending linear joint 23 is rotatably connected to the pin shaft one 541. When the screw shaft of the calf bending linear joint 23 is pushed out, the entire calf can be bent backward; the thigh leg lifting linear joint 22 and the calf bending linear joint 23 coordinate with each other to realize the bending movement of the thigh and calf, and realize anthropomorphic walking through control.

[0040] The arrangement of the connecting rod assembly optimizes the motion trajectory of the thigh-lifting and calf-bending movements, reduces singular points, and simultaneously increases the lever arm of the push-out force of the linear joints during the thigh-lifting and calf-bending movements, making the output of the linear joints smoother throughout the entire process and reducing impact. Simplifying the bipedal robot of this application, the thigh-lifting linear joint 22 pushes the thigh support plate 24 to rotate around the thigh adapter 25 to achieve the thigh-lifting movement, and the calf-bending linear joint 23 pushes the calf support plate 32 to rotate around the thigh support plate 24 to achieve the calf-bending movement.

[0041] Furthermore, connecting rod three 54 includes a first connecting portion 543 and a symmetrically arranged second connecting portion 544 extending to the side, the second connecting portion 544 is provided with a connecting hole for the pin shaft 1 541 to pass through, connecting rod four 55 is provided with a lug 551 connected to the pin shaft 1 541, and the other end of connecting rod four 55 is connected to the calf support plate 32.

[0042] In some embodiments, the ankle linear joint 31 includes an ankle linear joint 1 311 and an ankle linear joint 2 312 arranged side by side, one end of which is rotatably connected to the calf support plate 32, and the other end of which is rotatably connected to the sole assembly 4. The lower end of the calf support plate 32 is provided with a cross shaft 33 ( Figure 8 The calf support plate 32 is connected to the sole assembly 4 (as shown in FIG. 1 ). Ankle linear encoder 3 63 and ankle linear encoder 4 64 are mounted on the cross shaft 33. The cross shaft 33 connects the calf support plate 32 to the sole assembly 4, ensuring that the sole assembly 4 can rotate relative to the calf support plate 32 in two directions. When the ankle linear joint 1 311 and the ankle linear joint 2 312 are jointly extended or retracted, the sole assembly 4 can achieve pitch motion. When the ankle linear joint 1 311 and the ankle linear joint 2 312 perform differential motion, the sole assembly 4 can achieve roll motion.

[0043] Furthermore, the thigh rotation joint 21 includes: thigh rotation joint 1 211 and thigh rotation joint 2 212. The rotation axes of thigh rotation joint 1 211 and thigh rotation joint 2 212 are perpendicular. Thigh rotation joint 1 211 and thigh rotation joint 2 212 are both installed on the main connecting part 1. Thigh rotation joint 2 212 is connected to thigh connection joint 1, and thigh connection joint 2 is driven to rotate by thigh connection joint 1. Thigh rotation joint 2 212 is connected to thigh adapter 25. The application of rotation joints in robots is existing technology and there are many options. Its specific structure will not be described here.

[0044] Furthermore, the thigh support plates 24 are symmetrically arranged, and the thigh leg lifting linear joint 22 and the calf bending linear joint 23 are located between the thigh support plates 24 .

[0045] In this application, there is also an encoder inside the thigh leg lifting linear joint 22. The two encoders work together to achieve closed-loop control, avoiding errors in the transmission process, reducing the amount of calculation required to solve the rotation angle of the thigh support plate 24, and avoiding calculation errors. Similarly, linear joint encoder 1 61 and linear joint encoder 2 62 are installed between the thigh support plate 24 and between the thigh support plate 24 and the calf support plate 32. They can directly and accurately read the rotation angle and speed data of the calf support plate 32, and cooperate with the calf bending linear joint 23 to achieve closed-loop control of the dual encoders. Similarly, linear joint encoder 3 and linear joint encoder 4 installed at the ankle position can directly read the data of the Pitch and Roll motion of the sole assembly 4, and form a closed-loop control with the ankle linear joint 31.

[0046] In some embodiments, the present application also discloses a linear actuator (such as Figure 9The biped robot comprises a shell 7, a motor 71, a planetary ball screw set, and an encoder 73. The motor 71 is arranged in the shell 7, and the motor 71 has a stator 711 and a rotor 712. The planetary ball screw set comprises an output shaft 74 and a screw nut 75. The rotor 712 is sleeved on the outer surface of the screw nut 75, so that the space occupied by the motor is reduced. The screw nut 75 is provided with a bearing seat at one end, and the bearing seat is provided with a bearing. The encoder 73 is arranged at one end of the screw nut 75 and is mounted on the bearing seat. The motor 71 drives the screw nut 75 to rotate, and the output shaft 74 is pushed out or retracted. At the same time, the encoder 73 senses the rotating speed and angle of the screw nut 75, so that the rotating angle and speed of the rotor 712 of the motor 71 can be directly obtained, the control of the motor 71 is realized, and a separate speed reducer is not needed, so that the total length of the actuator is greatly shortened.

[0047] Further, the shell 7 is provided with a connecting seat one 76 and a connecting seat two 77 on both sides, so that the linear actuator can be installed and fixed. The connecting seat one 76 is connected with the shell 7 through a sensor 78, and the connecting seat two 77 is connected with the extending end of the output shaft 74. The sensor 78 can be a force sensor, which can directly read the tension or pressure data of the linear actuator during the action process, and compare the torque data of the motor 71 to realize the closed-loop control of force / torque.

[0048] Further, the screw nut 75 is provided with bearings on both sides, and the shell 7 is provided with sealing covers 72 at both ends. The sealing cover 72 is provided with a sealing assembly, which comprises a sealing ring arranged outside the bearing and an oil seal arranged at the position of the output shaft 74, so as to ensure the waterproof effect of the linear actuator and make the application scene of the linear actuator more extensive.

[0049] The application has the following advantages:

[0050] 1. The biped robot of the application adopts a linear actuator for the actuator, which can provide large load capacity, and the system stress can be optimized through four-link design.

[0051] 2. By arranging the encoder at the joint rotation position, the closed-loop control of the speed and position of the double encoders of the biped robot can be realized. Compared with the scheme of directly adding a displacement sensor at the position of the output shaft 74 of the linear actuator or a single encoder, the error in the transmission process and the calculation conversion process is eliminated, the control accuracy is improved, and the control difficulty is reduced. By arranging the force sensor at the end of the actuator, the closed-loop control of the force / torque of the actuator is realized.

[0052] 3. The linear actuator adopts the transmission scheme of the planetary ball screw, which has the characteristics of large load, high motion precision, long service life, small size, etc., and can meet the requirements of large load, high response speed and high precision of the biped robot.

[0053] 4、 The linear actuator is a waterproof actuator, which can meet the needs of more application scenarios with higher protection requirements.

[0054] For those skilled in the art, without departing from the inventive concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application.

Claims

1. A bipedal robot, characterized in that: The application relates to a robot leg mechanism, which comprises a main body connecting part (1) and leg parts arranged on both sides of the main body connecting part (1), wherein the leg parts comprise a thigh part (2), a shank part (3), a foot sole assembly (4) and a connecting rod assembly for connection in sequence; the thigh part (2) comprises a thigh rotating joint (21), a thigh lifting linear joint (22), a shank bending linear joint (23) and a thigh support plate (24), the thigh lifting linear joint (22) and the shank bending linear joint (23) are both linear actuators and are reversely arranged, and both ends of the thigh lifting linear joint (22) and both ends of the shank bending linear joint (23) are rotatably arranged; the shank part (3) comprises an ankle linear joint (31) and a shank support plate (32), the upper end of the ankle linear joint (31) is rotatably connected with the shank support plate (32), and the lower end of the ankle linear joint (31) is connected with the foot sole assembly (4). The connecting rod assembly comprises a connecting rod one (51) and a connecting rod two (52) for connecting the thigh rotating joint (21), the thigh lifting linear joint (22) and the thigh support plate (24), and further comprises a connecting shaft (53) for connecting the thigh support plate (24) and the thigh rotating joint (21), wherein the connecting shaft (53) is provided with a linear joint encoder one (61).

2. The biped robot according to claim 1, characterized by, The connecting rod assembly further comprises a connecting rod three (54) and a connecting rod four (55) for connecting the thigh part (2) and the shank part (3), the connecting rod three (54) and the connecting rod four (55) are connected through a pin shaft one (541), the thigh support plate (24) and the shank support plate (32) are further connected through a pin shaft two (542), and the pin shaft two (542) is provided with a linear joint encoder two (62).

3. The biped robot according to claim 1, characterized by, The connecting rod three (54) comprises a first connecting part (543) and symmetrically arranged second connecting parts (544) extending to the side surfaces, the second connecting parts (544) are provided with connecting holes for the pin shaft one (541) to pass through, the connecting rod four (55) is provided with lugs (551) for being connected with the pin shaft one (541), and the other end of the connecting rod four (55) is connected with the shank support plate (32).

4. The biped robot according to claim 3, characterized by, The ankle linear joint (31) comprises an ankle linear joint one (311) and an ankle linear joint two (312) arranged side by side, one end of the ankle linear joint one (311) and the ankle linear joint two (312) is rotatably connected with the shank support plate (32), and the other end is rotatably connected with the foot sole assembly (4), the lower end of the shank support plate (32) is provided with a cross rotating shaft (33) connected with the foot sole assembly (4), and the cross rotating shaft (33) is provided with an ankle linear encoder three (63) and an ankle linear encoder four (64).

5. The biped robot according to claim 1, characterized by, The thigh rotating joint (21) comprises a thigh rotating joint one (211) and a thigh rotating joint two (212), and the rotating axes of the thigh rotating joint one (211) and the thigh rotating joint two (212) are perpendicular.

6. The biped robot according to claim 1, characterized by, The thigh support plate (24) is symmetrically arranged, and the thigh lifting linear joint (22) and the shank bending linear joint (23) are located between the thigh support plates (24).

7. The biped robot according to claim 1, characterized by, ​ 8. A linear actuator characterized by, The biped robot of any one of claims 1-7 comprises a housing (7), a motor (71), a planetary ball screw set, and an encoder (73), the motor (71) is arranged in the housing (7), the planetary ball screw set comprises an output shaft (74) and a screw nut (75), the screw nut (75) is connected with the motor (71), and the encoder (73) is arranged at one end of the screw nut (75).

9. The linear actuator of claim 8, wherein, Both sides of the housing (7) are provided with a connecting seat one (76) and a connecting seat two (77), the connecting seat one (76) is connected with the housing (7) through a sensor (78), and the connecting seat two (77) is connected with the extended end of the output shaft (74).

10. The linear actuator of claim 9, wherein, Both sides of the screw nut (75) are provided with bearings, both ends of the housing (7) are provided with sealing covers (72), and the sealing covers (72) are provided with sealing assemblies.

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