CN105945983B - A kind of energy-saving vibration-damping bionic knee joint for bipod walking robot - Google Patents

Abstract

The invention discloses an energy-saving shock-absorbing bionic knee joint for a bipedal walking robot, which includes a bionic femur, a bionic tibia and a bionic patella; a cylinder is fixedly connected to a femoral condyle connecting piece through a cylinder bracket, and the knee extension movement of the knee joint is performed by The cylinder actively does work to complete. The bionic femoral condyle is in contact with the third roller through the first slide rail to realize the support and guidance of the meniscus component to the bionic femoral condyle, and at the same time, the second roller rolls in the second slide rail to simulate the motion of the human knee joint transient center , the second sliding rail has two motion limit positions to realize the limitation of the range of motion of the knee joint. The patella assembly simulates the human patella through the movement of the first roller in the first slide rail, which can increase the force arm of the output force of the cylinder in the knee extension movement, thereby saving energy. The present invention achieves the beneficial effects of transient cardiac motion of the knee joint, low energy consumption and high cushioning performance by introducing bionic femoral condyle, bionic patella and meniscus components.

Description

An energy-saving shock-absorbing bionic knee joint for a biped walking robot

technical field

The invention belongs to the field of robots, and in particular relates to an energy-saving shock-absorbing bionic knee joint for a biped walking robot.

Background technique

Because of its shape and movement mode are very close to human beings, the biped walking robot is suitable for working in the living environment of human beings and completing tasks such as walking on complex road conditions and carrying heavy objects. Therefore, research work on biped walking robots has received extensive attention in recent years. However, the knee joints of the current biped walking robots are mostly designed in an articulated way, although the requirements for the rotational freedom of the robot knee joints in the sagittal plane are largely met, but the current mechanically articulated knee joints During flexion and extension, the position of the instantaneous center of rotation remains almost unchanged, so that the joint motion and its stability are completely maintained by external drive input, which to a large extent leads to an increase in energy consumption of the joint during walking , The movement is unnatural; at the same time, the completely rigid articulation method is not conducive to the shock absorption of the knee joint, which reduces the stability of the robot walking.

The human knee joint is the most complex joint of all joints in the human body. It is composed of femoral medial and lateral condyles, tibial medial and lateral condyles, and patella, and plays an important role in transmitting loads, absorbing vibrations and bearing pressure. Among them, the patella provides an important biomechanical function for the knee joint: it helps to straighten the knee joint by lengthening the moment arm of the quadriceps muscle throughout the movement process. The meniscus in the knee joint, in addition to its supporting function, also has a cushioning effect and can absorb certain load shocks. As mentioned above, the movement mode of the human knee joint is very different from the rotation mode of the existing mechanically articulated knee joint, and it is a kind of transient heart movement. Studies have shown that in the process of knee flexion and knee extension, the trajectory of the instantaneous center of rotation of the human knee joint is a "J"-shaped curve, which makes the knee joint that is mainly responsible for the knee extension movement during the movement process gradually flexed. The increasing moment arm of the quadriceps femoris may be an important reason for the efficient and labor-saving knee extension of the human body, but the knee joint design of the current biped walking robot has less consideration for this.

Looking at the research status of the knee joint of the biped walking robot and the excellent biological structure characteristics of the human knee joint, there is an urgent need for a bionic knee joint that can effectively improve the walking stability, naturalness and energy-saving characteristics of the biped walking robot.

Contents of the invention

The purpose of the present invention is to provide a bionic knee joint for a biped walking robot in order to solve the problems of high energy consumption, unnatural movement and unsatisfactory shock absorption performance of the existing biped walking robot knee joint. The joint improves the energy consumption and shock absorption performance of the biped walking robot while making its movement more natural.

The invention includes bionic femur, bionic tibia and bionic patella;

Described bionic femur comprises femoral condyle connector, cylinder, bionic femoral condyle, and bionic femoral condyle is connected with femoral condyle connector by the mode of screw connection, and cylinder bracket is fixedly connected on the femoral condyle connector by first nut; The cylinder barrel of the cylinder is fixedly connected on the cylinder support in a threaded manner.

The bionic tibia includes a tibial condyle component, a tibial condyle connector, and a meniscus assembly. The second roller forms a rotation pair with the second connecting shaft, and the second connecting shaft is fixedly connected to the tibial condyle component through a third nut. The tibial condyle component is fixed on the tibial condyle connector by four symmetrically distributed hexagon socket screws. The support plate is fixedly connected with the tibial condyle connector through the fourth nut. The four groups of meniscus components are symmetrically distributed, and the roller strut forms a sliding connection with the tibial condyle connector and the support plate, which guide and limit the roller strut; the pin shaft and the roller strut are fixed Connected, the third roller and the pin shaft form a rotating pair, and the compression spring converts the elastic potential energy into the kinetic energy of the axial movement of the roller rod through the retaining ring and the support plate.

The bionic patella includes a first extension spring, a patella assembly and a second extension spring. Wherein, the two ends of the first tension spring are respectively connected with the cylinder joint and the first patella component, and here, the cylinder joint is fixedly connected with the cylinder piston through threaded connection. The second tension spring is symmetrically distributed, and its two ends are respectively connected with the second patella member and the holed screws. Here, the same symmetrically distributed holed screws are fixedly connected with the tibial condyle connector through threaded connection. The first patella component and the second patella component are respectively hinged to the first connection shaft, and the symmetrically distributed first rollers form a rotation pair with the first connection shaft. At the same time, the patella assembly completes the determination of the relative assembly relationship of all parts of the patella assembly through the shaft sleeve and the second nut. Here, the second nut is fixedly connected with the first connecting shaft through threaded connection.

The bionic femoral condyle, tibial condyle component, first roller, second roller and third roller are made of POM engineering plastics.

Working process and principle of the present invention:

In the specific implementation process, the bionic femoral condyle is in contact with the third roller through the first slide rail to realize the support and guiding effect of the meniscus component on the bionic femoral condyle, and at the same time, the second roller rolls in the second slide rail to realize the approximation The J-shaped curve trajectory movement of the instantaneous center of the human knee joint completes the knee flexion and knee extension movements. The second slide rail has two movement limit positions to realize the limitation of the knee flexion and knee extension movement range. The patella assembly simulates the function of the human patella through the movement of the first roller in the first slide rail, which can increase the force arm of the cylinder output force in the knee extension movement, and then reduce the drive output of the cylinder under the same joint torque demand , play the role of energy saving. Here, the application of the first roller changes sliding friction into rolling friction, which can effectively improve joint flexibility and reduce energy consumption. During the knee extension process of the bionic knee joint, the cylinder actively performs work, and the knee extension action is completed through the contraction of the cylinder piston. When the biped robot maintains a standing posture, the bionic knee joint is in the extreme position of knee extension, and the cylinder needs to be in a pressure-holding state to maintain a stable posture of the knee joint. In the process of knee flexion, the air pressure input of the cylinder is closed, and the passive knee flexion is completed entirely by the gravity of the bionic tibia. Since the knee joint of the biped walking robot has a relatively small knee flexion angle in the sagittal plane during walking, the present invention designs the passive knee flexion range of the bionic knee joint to be 0-90°.

Beneficial effects of the present invention:

1. The femoral condyle adopts bionic design, which can make the instantaneous heart of the bionic knee joint realize a motion trajectory similar to that of the human knee joint during the process of knee flexion and extension, and improve the naturalness of joint movement.

2. The meniscus component adopts a roller support design, which greatly reduces friction and helps to reduce the energy consumption of the knee joint. At the same time, the introduction of the spring in the meniscus component improves the cushioning and shock absorption capacity of the bionic knee joint.

3. The bionic patella can reduce the drive output of the cylinder under the same joint torque demand by extending the force arm of the cylinder during the whole movement process, thereby saving energy.

4. In the present invention, the bionic femoral condyle, tibial condyle member, first roller, second roller, and third roller are all made of POM engineering plastics, which have excellent self-lubricating properties, thereby reducing friction and improving knee joint flexibility.

Description of drawings

Fig. 1 is a schematic structural view of the present invention in a fully extended knee state.

Fig. 2 is a right side view of Fig. 1 .

Fig. 3 is a bottom view of Fig. 1 .

Fig. 4 is the A-A view of Fig. 3 .

Fig. 5 is a schematic diagram of the structure of the present invention in a fully bent state.

Fig. 6 is a schematic perspective view of the present invention.

Among them: 1-femoral condyle connector; 2-cylinder; 21-cylinder barrel; 22-cylinder piston; 3-first nut; 4-cylinder bracket; 5-cylinder joint; 6-first tension spring; 7- Patella assembly; 71-first patella component; 72-shaft sleeve; 73-first roller; 74-first connecting shaft; 75-second nut; 76-second patella component; 8-bionic femoral condyle; 81-the first 1 slide rail; 82-second slide rail; 9-second tension spring; 10-second roller; 11-third nut; 12-second connecting shaft; 13-tibial condyle member; 14-tibial condyle connector ;15-meniscus assembly; 151-third roller; 152-pin shaft; 153-roller strut; 154-retaining ring; 155-compression spring; 16-support plate; ;19-hole screw.

detailed description

Please refer to Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5 and Fig. 6, the present embodiment includes bionic femur, bionic tibia and bionic patella;

Described bionic femur comprises femoral condyle connector 1, cylinder 2 and bionic femoral condyle 8, and bionic femoral condyle 8 is fixedly connected with femoral condyle connector 1 by the mode of threaded connection, and cylinder bracket 4 is fixedly connected in femoral condyle by first nut 3. On the condyle connector 1; the cylinder 2 is fixedly connected to the cylinder bracket 4 through the cylinder barrel 21 in a threaded manner;

Described bionic tibia comprises tibial condyle member 13, tibial condyle connector 14 and meniscus assembly 15; Second roller 10 forms rotation pair with second connecting shaft 12, and second connecting shaft 12 is connected with tibial condyle member through the 3rd nut 11 13 is fixedly connected, the tibial condyle component 13 is fixedly connected to the tibial condyle connector 14 through four symmetrically distributed hexagon socket head screws 18, and the support plate 16 is fixedly connected to the tibial condyle connector 14 through the fourth nut 17; four groups of meniscus components 15 is symmetrically distributed, the roller strut 153 forms a sliding connection with the tibial condyle connector 14 and the support plate 16, and the tibial condyle connector 14 and the support plate 16 play the role of guiding and limiting the roller strut 153; the pin shaft 152 and the roller The pole 153 is fixedly connected, the third roller 151 and the pin shaft 152 form a rotating pair, and the compression spring 155 converts the elastic potential energy into the kinetic energy of the axial movement of the roller pole 153 through the retaining ring 154 and the support plate 16;

The bionic patella includes a first extension spring 6, a patella assembly 7 and a second extension spring 9; the two ends of the first extension spring 6 are respectively connected to the cylinder joint 5 and the first patella member 71, and the cylinder joint 5 passes through The way of threaded connection is firmly connected with the cylinder piston 22, a pair of second tension springs 9 are symmetrically distributed, and the two ends are respectively connected with the second patella member 76 and the holed screws 19, and the symmetrically distributed pair of holed screws 19 are connected by threads The mode is fixedly connected with the tibial condyle connector 14, the first patella component 71 and the second patella component 76 are respectively hinged with the first connecting shaft 74, and the symmetrically distributed first rollers 73 form a rotation pair with the first connecting shaft 74; the patella assembly 7 The relative assembly relationship of the patella assembly 7 is determined through the symmetrically distributed shaft sleeves 72 and the second nut 75, and the second nut 75 is fixedly connected with the first connecting shaft 74 through threaded connection.

The bionic femoral condyle 8 is in contact with the third roller 151 through the first slide rail 81 to realize the supporting and guiding effect of the meniscus assembly 15 on the bionic femoral condyle 8, and at the same time, the second roller 10 rolls in the second slide rail 82 to realize approximation The J-shaped curve track movement of the instantaneous center of the human knee joint completes the knee flexion and knee extension motions. There are two movement limit positions in the second slide rail 82 to realize the limitation of the knee flexion and knee extension range of motion; the patella assembly 7 passes through the first roller 73 moves in the first slide rail 81 to simulate the function of the human patella, which can increase the force arm of the output force of the cylinder 2 in the knee extension movement, and then reduce the drive output of the cylinder under the same joint torque demand, thereby saving energy role. Here, the application of the first roller 73 changes sliding friction into rolling friction, which can effectively improve joint flexibility and reduce energy consumption. During the knee extension process of the bionic knee joint, the cylinder 2 actively performs work, and the knee extension action is completed through the contraction of the cylinder piston 22 . When the biped robot maintains a standing posture, the bionic knee joint is in the extreme position of knee extension, and the cylinder 2 needs to be in a pressure-holding state to maintain a stable posture of the knee joint. In the process of knee flexion, the air pressure input of cylinder 2 is closed, and the passive knee flexion is completed completely by the gravity of the bionic tibia.

The bionic femoral condyle 8, tibial condyle component 13, first roller 73, second roller 10 and third roller 151 are made of POM engineering plastics.

Claims (3)

1. An energy-saving shock-absorbing bionic knee joint for a biped walking robot, characterized in that: it includes a bionic femur, a bionic tibia and a bionic patella; The bionic femur comprises a femoral condyle connector (1), a cylinder (2) and a bionic femoral condyle (8), the bionic femoral condyle (8) is fixedly connected with the femoral condyle connector (1) by a threaded connection, and the cylinder bracket (4) be fixedly connected on the femoral condyle connector (1) by the first nut (3); the cylinder (2) is fixedly connected on the cylinder support (4) by the mode of threaded connection through the cylinder cylinder (21); Described bionic tibia comprises tibial condyle member (13), tibial condyle connector (14) and meniscus assembly (15); The second roller (10) and the second connecting shaft (12) form a rotation pair, and the second connecting shaft (12) The third nut (11) is fixedly connected to the tibial condyle component (13), and the tibial condyle component (13) is fixedly connected to the tibial condyle connector (14) by four symmetrically distributed hexagon socket screws (18), The support plate (16) is fixedly connected with the tibial condyle connector (14) through the fourth nut (17); the four groups of meniscus components (15) are symmetrically distributed, and the roller struts (153) are connected with the tibial condyle connector (14), support The plate (16) forms a sliding connection, and the tibial condyle connector (14) and the support plate (16) play the role of guiding and limiting the roller strut (153); the pin shaft (152) is fixed to the roller strut (153) Connected, the third roller (151) and the pin shaft (152) form a rotating pair, and the compression spring 155 converts the elastic potential energy into the kinetic energy of the axial movement of the roller pole (153) through the retaining ring 154 and the support plate 16; The described bionic patella comprises a first extension spring (6), a patella assembly (7) and a second extension spring (9); the two ends of the first extension spring (6) are connected with the cylinder joint (5) and the second extension spring respectively A patella component (71) is connected, the cylinder joint (5) is fixedly connected with the cylinder piston (22) through a threaded connection, a pair of second tension springs (9) are symmetrically distributed, and the two ends are connected to the second patella component (76) respectively. ) and holed screws (19), a pair of symmetrically distributed holed screws (19) are fixedly connected with the tibial condyle connector (14) through threaded connection, the first patella component (71), the second patella component ( 76) are respectively hinged with the first connecting shaft (74), and the symmetrically distributed first rollers (73) form a rotating pair with the first connecting shaft (74); the patella assembly (7) passes through the symmetrically distributed axle sleeves (72), The second nut (75) completes the determination of the relative assembly relationship of the patella component (7), and the second nut (75) is fixedly connected with the first connecting shaft (74) through threaded connection. 2. A kind of energy-saving and shock-absorbing bionic knee joint for a biped walking robot according to claim 1, characterized in that: the bionic femoral condyle (8) passes through the first slide rail (81) and the third roller (151) contact to realize the support and guidance of the meniscus assembly (15) to the bionic femoral condyle (8), and to realize the approximate human knee joint instantaneous center by rolling the second roller (10) in the second slide rail (82) The J-shaped curve trajectory movement of the knee is completed to bend and extend the knee, and there are two movement limit positions in the second slide rail (82) to realize the limitation of the range of motion of the knee to bend and extend the knee; the patella assembly (7) passes through the first roller ( 73) The movement in the first slide rail (81) simulates the action of the human patella. 3. A kind of energy-saving shock-absorbing bionic knee joint for biped walking robot according to claim 1, characterized in that: the bionic femoral condyle (8), tibial condyle component (13), first roller ( 73), the second roller (10) and the third roller (151) are made of POM engineering plastics.