CN106826763B - Flexible exoskeleton robot for climbing knee joint power-assisted - Google Patents

Abstract

A flexible exoskeleton robot used for assisting knee joints in the climbing process, which relates to a lower limb assisting exoskeleton robot to solve the problem of large volume, heavy weight, and human body due to the rigid configuration of the existing lower limb assisting exoskeleton robot. Low fusion, poor flexibility, high energy consumption, and the inability to perform soft and adaptive auxiliary motion for the knee joint during the climbing process of the human body, including the variable torque drive device, left leg, right leg and transmission components; left leg and right leg Including the thigh and the lower leg respectively; the variable torque drive device includes a motor, a support frame and a drive turntable; the transmission assembly includes two ropes, two Bowden wire tubes and two Bowden wire tube fixed joints; the drive turntable It is mainly composed of a cam winch interface plate connected as one and two cam winches; the thigh and the lower leg are rotatably connected. The invention is used for assisting the knee joint in the climbing process of the human body.

Description

Flexible exoskeleton robot for knee assist during climbing

technical field

The invention relates to a lower limb assisting exoskeleton robot, in particular to a flexible exoskeleton robot used for knee joint assisting during climbing.

Background technique

At present, power-assisted exoskeleton robots basically use rigid connecting components, and use a drive system to directly drive these rigid connecting components, thereby driving the human body and the exoskeleton to move together. This rigid exoskeleton configuration design increases the volume and overall quality of the exoskeleton system, greatly affects the fusion of the exoskeleton configuration and the human body, limits the anthropomorphic degree of the exoskeleton robot, and affects the exoskeleton. The coordinated movement of the robot and the human body simultaneously limits the movement flexibility of the entire exoskeleton system and increases the energy consumption of the system. For exoskeleton robots using steel wire rope as the drive, the variable torque adaptive drive is performed according to the torque required for different stages of the human body's motion gait, which requires a relatively complicated control algorithm to realize. In addition, the current power-assisted exoskeleton robots are mainly aimed at assisting the human body to walk on flat ground, and there are few exoskeleton robots that assist the human body in climbing.

Contents of the invention

The present invention aims to solve the problem of large volume, heavy weight, low integration with the human body, poor flexibility, and high energy consumption caused by the rigid configuration of the existing lower limb power-assisted exoskeleton robot, and it cannot be aimed at the knee joint during the climbing process of the human body. To solve the problem of soft and adaptive auxiliary motion, and then provide a flexible exoskeleton robot for knee joint assist in climbing process.

The technical scheme that the present invention takes for solving the above problems is:

A flexible exoskeleton robot used for assisting knee joints in the climbing process, which includes a variable torque drive device, a left leg, a right leg, and a transmission assembly; the left leg and the right leg include a thigh and a calf, respectively;

The variable torque driving device includes a motor, a support frame and a driving turntable; the transmission assembly includes two ropes, two Bowden wire tubes and two Bowden wire tube fixed joints;

The drive turntable is mainly composed of a cam winch boundary plate and two cam winches connected as one; the cam winch boundary plate and the two cam winches are processed with a drive turntable shaft, and the two cam winches are arranged symmetrically; the cam winch boundary Between the disc and the two cam capstans, rope grooves for winding ropes are respectively processed, and the winding directions of the ropes in the two rope grooves are opposite;

The drive turntable shaft is rotatably mounted on the support frame, the output shaft of the motor is fixed in the shaft hole of the drive turntable shaft, and the motor is fixed on the support frame through a motor connecting flange; The thigh and the shank are rotationally connected, and the back side of the thigh is provided with a guide hole for a Bowden wire tube;

The support frame is fixed with two fixed joints of the Bowden wire pipe; one end of the Bowden wire pipe is fixed through the Bowden wire pipe fixed joint, and the Bowden wire pipe is installed in the guiding channel of the Bowden wire pipe. The other end of the boarding wire tube is fixed at the lower port of the Bowden wire tube guide tunnel, one end of the rope in the rope groove is wound and fixed on the rope groove, the rope 7 is passed through the Bowden wire tube, and the other end of the rope It is fixed on the back side of the lower leg.

The beneficial effects of the present invention are as follows: 1. The present invention adopts a flexible design of light materials, which is convenient to carry; 2. A motor and a driving turntable are used to alternately drive the left leg and the right leg, and the overall structure is compact and light in weight; 3. The overall structure The shape design is highly anthropomorphic and highly adaptable to the physiological parameters of the human body; 4. The legs are made of 3D printed lightweight elastic material, which greatly reduces the overall weight and is more compliant; Sexual driving effect; 6. The drive output combined with the human climbing movement gait cycle corresponds to the required torque, realizing functional anthropomorphism, saving energy and improving battery life; 7. Assisting the human knee joint to exert force during climbing to improve human motion ability , reduce the body's metabolism. The overall weight of the present invention including the electronic control system is no more than 3kg.

Description of drawings

Fig. 1 is the three-dimensional structure schematic diagram of the present invention;

Fig. 2 is a structural schematic diagram of a variable torque drive device;

Fig. 3 is the front view of Fig. 2 without end cap;

Figure 4 is an exploded view of the variable torque drive device;

Fig. 5 is a schematic structural view of the drive turntable in Fig. 4;

Fig. 6 is a structural schematic view of the drive turntable viewed from the motor side in Fig. 4;

Figure 7 is a side view of the drive turntable;

Fig. 8 is a side view of the connecting structure of the thigh, the shank and the Bowden wire pipe guide hole;

Fig. 9 is a schematic diagram of the interconnection structure of the thigh, the shank, the guiding channel of the Bowden wire pipe and the interconnection of the Bowden wire pipe;

Figure 10 is a schematic diagram of the structure of the lower leg;

Figure 11 is a schematic diagram of the thigh structure;

Fig. 12 is a working principle diagram of the present invention.

Detailed ways

The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and through specific implementation methods.

In conjunction with Fig. 1-Fig. 11, the flexible exoskeleton robot used for assisting the knee joint in the climbing process includes a variable torque drive device, a left leg, a right leg and a transmission assembly; the left leg and the right leg respectively include a thigh 9 and a calf 10;

The variable torque drive device includes a motor 1, a support frame 13 and a drive turntable 4; the transmission assembly includes two ropes 7, two Bowden wire tubes 12 and two Bowden wire tube fixed joints 8;

The drive turntable is mainly composed of a cam winch boundary plate 4-2 and two cam winches 4-1 connected as one; the cam winch boundary plate 4-2 and the two cam winches 4-1 are processed with a drive turntable shaft 4-3 , the two cam winches 4-1 are arranged symmetrically; a rope groove 4-1-1 for winding the rope 7 is respectively processed between the cam winch boundary disc 4-2 and the two cam winches 4-1, The winding directions of the ropes 7 in the two rope grooves 4-1-1 are opposite;

The drive turntable shaft 4-3 is rotatably mounted on the support frame 13, the output shaft of the motor 1 is fixed in the shaft hole of the drive turntable shaft 4-3, and the motor 1 is connected to the flange 2 through the motor. Fixedly installed on the support frame 13; the thigh 9 and the shank 10 are rotationally connected, and the back side of the thigh 9 is provided with a Bowden wire tube guide hole 9-1;

The support frame 13 is fixedly equipped with two fixed joints 8 of the Bowden wire pipe; one end of the Bowden wire pipe 12 is fixed by the Bowden wire pipe fixed joint 8, and the Bowden wire pipe 12 is installed on the Bowden wire pipe. In the guide hole 9-1, the other end of the Bowden wire tube 12 is fixed at the lower port of the Bowden wire tube guide hole 9-1, and one end of the rope 7 in the rope groove 4-1-1 is wound and fixed on the said Bowden wire tube guide hole 9-1. On the rope groove 4-1-1, the rope 7 is passed through the Bowden wire tube 12, and the other end of the rope 7 is fixedly connected to the back side of the lower leg 10.

The external dimensions of the two cam winches 4-1 of this embodiment are exactly the same, and they are symmetrically distributed on both sides of the cam winch boundary plate 4-2, so that when the drive turntable shaft 4-3 is oriented to rotate in one direction, the two cam winches 4 -1 are respectively in the working state of receiving and releasing the rope, and as the rotation direction of the drive turntable shaft 4-3 changes, the two cam capstans 4-1 alternately change the working state, thereby realizing that one group of ropes is in the driving joint state, and Another set of ropes is in a relaxed state to realize variable torque drive output. The change range of the effective moment arm of the rope outlet point on the outer edge of the two cam winches 4-1 is R ₁ ~R ₂ mm (R ₁ <R ₂ ). The thigh 9 and the lower leg 10 are made by 3D printing of light elastic material, which itself has strong elasticity. The thigh 9 and the calf 10 are connected through the mating connection between the thigh rotation hole 9-2 and the calf rotation shaft 10-1 to realize the relative rotation between the thigh 9 and the calf 10. There is a steel wire rope or Kevlar inside the Bowden wire tube 12 rope or carbon fiber rope and other ropes 7, the Bowden wire tube 12 passes through the Bowden wire tube guide hole 9-1, and ends at the port of the hole, and the inside of the Bowden wire tube 12 has a rope 7 directly across the thigh 9 and the calf 10, Be fixed on the shank wire rope fixed end 10-2 by the wire rope chuck. The thigh 9 and the calf 10 are respectively provided with two leg straps 11, and the thigh 9 and the calf 10 are respectively fixed on the legs of the human body through the leg straps 11, so that the light and flexible exoskeleton can drive the lower limbs of the human body to move. When the motor 1 rotates and pulls the ropes 7 on the corresponding thighs 9 and shanks 10, the thighs 9 and the shanks 10 are fixed with the human body by leg straps 11. Short, so that the thigh 9 rotates around the rotation axis relative to the calf 10, so as to realize the lifting of the overall center of gravity of the human body, so as to achieve the assisting of the knee joint in the climbing process and assist the human body to climb.

Referring to FIG. 1 , preferably, the rope 7 is a steel wire rope, a Kevlar rope or a carbon fiber rope. With such setting, the steel wire rope has good flexibility and high strength. Kevlar rope has high temperature resistance, fire and flame retardant, light weight, high strength, high modulus, stable size, low shrinkage, puncture resistance, wear resistance, heat resistance, chemical corrosion resistance, good mechanical properties, medium Good electrical properties and other advantages; carbon fiber rope has high strength, which is easy to ensure the accuracy of repeated deployment.

Referring to Fig. 1 and Fig. 8-Fig. 11, both the thigh 9 and the lower leg 10 are made of lightweight elastic material. Such arrangement greatly reduces the weight of the whole device.

2-4, the support frame 13 includes a support shell 3 and a support shell end cover 5; the support shell end cover 5 is installed on the support shell 3, and the drive turntable shaft 4-3 is arranged on the The support shell 3 is installed in the support shell 3 and the end cover 5 of the support shell rotatably, the motor 1 is fixed on the support shell 3 through the motor connection flange 2, and the two Bowden The wire pipe fixing joint 8 is fixedly installed on the support shell 3 . The motor connection flange 2 of this embodiment is fixed on the support shell 3 by bolts, the drive turntable shaft 4-3 is connected to the output shaft of the motor 1 through a key, and the drive turntable shaft 4-3 is fixed on the support shell 3 and the support by a bearing. On the supporting hole of the shell end cover 5, ensure that the axis of the motor 1, the center of rotation of the drive turntable 4 coincide with the central axis of the support shell 3 and the support hole of the support shell end cover 5, and the drive turntable 4 can rotate synchronously with the motor 1. The rope 7 is wound in the rope groove 4-1 of the drive turntable 4, and the Bowden wire tube fixing joint 8 is fixed on the supporting shell 3 for conducting steel wire rope or Kevlar rope or carbon fiber rope.

3 and 4, the variable torque drive device also includes two rope guide wheels 6, the two rope guide wheels 6 are installed on the support shell 3, and the two rope guide wheels 6 are connected to the two The Bowden wire pipe fixing joints 8 are arranged in one-to-one correspondence, and the rope 7 is supported on the rope guide wheel 6 . In this way, the rope guide wheel 6 is fixed on the supporting shell 3 by bolts, and when the driving turntable 4 rotates synchronously with the motor 1 to drive the rope 7, it guides the steel wire rope, Kevlar rope or carbon fiber rope.

Referring to FIG. 2 and FIG. 4 , preferably, the motor 1 is a servo motor. With such setting, the linearity is high, the starting torque is large, and the operation is stable and reliable.

working principle:

The knee joint of the present invention is set as an active power-assisted joint, adopts a flexible drive mode driven by a steel wire rope with variable torque, utilizes the motor 1, the cam winch 4-1, the steel wire rope or rope 7, the thigh 9 and the calf 10 to form a new type of joint Variable torque flexible drive system. The steel wire rope is wound on the cam winch 4-1 of the variable effective force arm. With the rotation of the motor 1, the variable torque power output can be realized. At the lower part of the joint, the motor 1 drives the cam winch 4-1 to wind the wire rope to reduce the length of the wire rope. The fixed end 10-2 of the wire rope on the calf is used as a fixed point to realize the tension provided by the wire rope, which drives the whole body to lift, assists the knee joint, and completes the auxiliary Human climbing exercise.

This driving method uses a motor to alternately drive the legs during the climbing process of the human body to achieve variable torque output, which ensures that the system has a compact structure, light weight, low requirements on the motor, and the exoskeleton of the legs is elastic and highly structurally It is anthropomorphic and fits perfectly with the configuration of the lower limbs of the human body, and has strong flexibility and synergy.

In the variable torque drive device, the motor 1 drives the drive turntable 4 to drive the wire rope, and the two symmetrically distributed cam capstans 4-1 on the drive turntable 4 wind and loosen the wire rope, respectively to the two different legs of the human body. Force driving and free relaxation, when the human body climbs, the cam winch 4-1 winds the wire rope on the side of the pedaling leg, and the cam winch 4-1 at the other end relaxes the driving wire rope of the swing leg, allowing the swing leg to move freely. As shown in FIG. 12 , a cam winch 4-1 winds a steel wire rope to drive the human body to climb the supporting legs and provide climbing assistance for the human body. In Figure 12:

R _i —effective moment arm at a point i;

S _i — length of rope turned by the cam winch;

T ₀ —the output torque of the motor;

T _i —moment acting on the knee joint at a point i;

R ₀ —the radius of rotation of the knee joint;

R ₁ —The effective moment arm when winding the wire rope after the initial rotation;

R ₂ —The effective moment arm when winding the wire rope after the rotation;

θ—the angle of the knee joint after the supporting leg starts pedaling.

Through the relationship between the effective moment arm of the cam winch 4-1 and the knee joint rotation radius R ₀ , it can be obtained that when the system moves to point i, the moment acting on the knee joint is:

Because support leg does not move when going upstairs, the fixed connection of wire rope fixed point 10-2 and shank 10 also remains motionless, and wire rope or rope 7 are fixed on the thigh 9 of human body by Bowden line pipe 12, and wire rope or rope 7 can be in The Bowden wire tube 12 slides freely, and the Bowden wire tube 12 is fixedly connected to the human thigh through the leg strap 11. With the cam winch 4-1 winding the wire rope or the rope 7, the length of the wire rope or the rope 7 becomes smaller, and the knee joint The relationship between the change of the angle of the steel wire rope or the length of the rope 7 is:

Since the fixed point of the steel wire rope does not move, the steel wire rope will drive the entire thigh to rotate clockwise to realize the knee joint extension movement, so that the whole body of the human body can be lifted to complete the climbing action, and the resulting rotational moment acts on the knee joint. moment T _i .

The effective rotation radius range of the cam winch 4-1 is R ₁ ~ R ₂ mm (R ₁ < R ₂ ). Since the human body climbs, when the pedal leg initially exerts force, a large joint torque is required. At this time, the initial The effective moment arm when rotating and winding the steel wire rope is set to R ₁ mm. When the pedaling leg ends to exert force, a small joint torque is required. At this time, the effective moment arm when the winding wire rope ends is set to R ₂ mm. The lower limbs assist the exoskeleton If the radius of rotation of the knee joint is R ₀ mm (R ₁ <R ₂ <R ₀ ), then the output torque variable torque output and secondary amplification can be realized, and the amplification factor is R ₀ /R ₂ ~R ₀ /R ₁ .

Without increasing the power of the motor, a larger torque output can be achieved, and it can adapt to the change of the torque required for pedaling the legs and knee joints during the climbing process of the human body. Energy is saved, and the battery life of the system is improved without increasing the weight of the system.

The present invention has been disclosed above with preferred implementation examples, but it is not intended to limit the present invention. Any skilled person who is familiar with this profession can use the structure and technical content disclosed above to make some The changes or modifications are equivalent implementation cases with equivalent changes, but any simple modifications, equivalent changes and modifications made to the above implementation cases according to the technical essence of the present invention without departing from the content of the technical solutions of the present invention are still The scope of the technical solutions of the present invention.

Claims (6)

1. the flexible exoskeleton robot that is used for the knee joint assisting of climbing process is characterized in that: it comprises torque-variable driving device, left leg, right leg and transmission assembly; Left leg and right leg comprise thigh (9) and shank (10 respectively) ); The variable torque driving device includes a motor (1), a support frame (13) and a drive turntable (4); the transmission assembly includes two ropes (7), two Bowden wire tubes (12) and two Bowden Line pipe fixing joint (8); The drive turntable is mainly composed of a cam winch boundary plate (4-2) and two cam winches (4-1) connected as one; the cam winch boundary plate (4-2) and two cam winches (4-1) The drive turntable shaft (4-3) is processed, and the two cam winches (4-1) are arranged symmetrically; The rope grooves (4-1-1) for winding ropes (7) are respectively processed, and the winding directions of the ropes (7) in the two rope grooves (4-1-1) are opposite; the drive turntable shaft (4- 3) Rotate and install on the support frame (13), the output shaft of the motor (1) is fixed in the shaft hole of the drive turntable shaft (4-3), and the motor (1) is connected to the flange through the motor The disc (2) is fixed on the support frame (13); the thigh (9) and the lower leg (10) are connected in rotation, and the back side of the thigh (9) is provided with a Bowden wire pipe guide hole ( 9-1); the support frame (13) is fixedly equipped with two fixed joints (8) of the Bowden wire pipe; one end of the Bowden wire pipe (12) is fixed by the Bowden wire pipe fixed joint (8) , the Bowden wire tube (12) is passed through the Bowden wire tube guide hole (9-1), and the other end of the Bowden wire tube (12) is fixed in the Bowden wire tube guide hole (9-1) At the lower port, one end of the rope (7) in the rope groove (4-1-1) is wound and fixed on the rope groove (4-1-1), and the rope (7) is passed through the Bowden wire tube (12) Inside, the other end of the rope (7) is fixedly connected to the back side of the shank (10). 2. The flexible exoskeleton robot for knee joint assisting in climbing process according to claim 1, characterized in that: the rope (7) is a steel wire rope or a Kevlar rope or a carbon fiber rope. 3. The flexible exoskeleton robot for knee joint assisting in climbing process according to claim 1 or 2, characterized in that: the thigh (9) and the lower leg (10) are made of light elastic material. 4. the flexible exoskeleton robot that is used for climbing process knee joint power-assisted according to claim 3, is characterized in that: described bracing frame (13) comprises support shell (3) and support shell end cover (5); The support shell end cover (5) is installed on the support shell (3), and the drive turntable shaft (4-3) is arranged in the support shell (3) and is rotatably mounted on the support shell (3) and On the end cover (5) of the support shell, the motor (1) is fixed on the support shell (3) through the motor connection flange (2), and the two fixed joints of the Bowden wire tube (8 ) is fixedly mounted on the support shell (3). 5. The flexible exoskeleton robot for knee joint assisting in climbing process according to claim 4, characterized in that: said torque-variable driving device also includes two rope guide wheels (6), two said rope guide wheels (6) installed on the supporting shell (3), and the two said rope guide wheels (6) are arranged in one-to-one correspondence with the two said Bowden wire tube fixing joints (8), and the ropes (7) are supported on on the rope guide wheel (6). 6. The flexible exoskeleton robot for knee joint assisting in climbing process according to claim 5, characterized in that: the motor (1) is a servo motor.