CN106585761A - Horse-imitating gait planar connection rod type quadruped walking robot - Google Patents

Abstract

The invention provides a planar link-type four-legged walking robot imitating a horse gait, which is composed of a frame, a turning mechanism, a lower body and a leg mechanism. The turning mechanism and the leg mechanism are arranged at the four corners of the frame and are left-right symmetrical; The turning mechanism is mainly composed of a servo motor, a coupling and a straight-toothed bevel gear, which is fixed on the frame and connected to the lower body through a flange structure; the leg mechanism is composed of a thigh mechanism and a lower leg mechanism, and adopts a planar six-bar linkage mechanism , where the thigh mechanism adopts a crank-rocker mechanism, and the calf mechanism adopts a double-rocker mechanism; the leg mechanism is equipped with a shock absorber; by imitating a horse's gait, the legs are linked on a diagonal, and the robot can move smoothly in all directions. The invention has simple structure, easy control, good dynamic walking ability and low cost.

Description

A quadruped walking robot with planar linkage and horse-like gait

technical field

The invention relates to a plane link type quadruped walking robot imitating horse gait, which belongs to the technical field of robots.

Background technique

Robot technology is currently a high-tech recognized by researchers from all over the world. It integrates the latest research results of many disciplines such as mechanical design, computer and information processing technology, automation, sensor application technology and artificial intelligence technology. It can be said that robot technology is well-deserved A complex of mechatronic technologies.

At present, the mobile robots researched by various countries mainly include wheeled robots, legged robots and crawler robots. No matter what kind of robot is, it can smoothly pass through the ground with relatively small ripples, but when the ground ripples are relatively large, the energy loss of the wheeled robot will be aggravated. Doesn't work well at all on big and soft pavement. In contrast, crawler-type robots can move on softer roads with large ripples, but the maneuverability will be reduced and the body of this robot will also vibrate significantly, making the movement unstable. The footed robot developed now just makes up for the defects of the two moving mechanisms, and has become a research hotspot. Researchers have designed many bionic legged robots inspired by animals. This type of robot has relatively low requirements on road conditions, and only needs enough discrete footholds to achieve stable walking. However, this type of robot generally involves more complex control systems and some complex emerging technologies, so related technologies need to be supplemented and perfection; at the same time, the structure of this type of robot is relatively complex and the cost is high.

Contents of the invention

The object of the present invention is to provide a planar linkage quadruped walking robot with simplified mechanical structure, easy control, and horse-like gait that can realize straight walking, turning walking and smooth movement on complex road surfaces.

The object of the present invention is achieved like this: comprise double-layer frame, be arranged on four groups of turning mechanisms in the frame, the lower body that is connected with each turning mechanism lower end and the leg mechanism that is arranged on each lower body, Each set of turning mechanisms includes a DC hollow cup servo motor installed on the frame, a reducer connected to the output end of the DC hollow cup servo motor, a small bevel gear shaft connected to the output end of the reducer, and a small bevel gear shaft installed on the small bevel gear shaft. The small bevel gear, the large bevel gear shaft vertically arranged on the frame, the large bevel gear installed on the large bevel gear shaft, the small bevel gear meshes with the large bevel gear; each lower body and the corresponding large bevel gear shaft The lower end is fixed, and each leg mechanism includes a servo motor installed on the body, a crank connected to the end of the output shaft of the servo motor, a thigh link hinged to the end of the crank, and a thigh rod hinged to the end of the thigh link 1. The lower leg member hinged with the middle position of the thigh link, the thigh link is hinged with the middle position of the thigh member, the upper end of the thigh member is hinged on the lower body, the lower end of the thigh member is hinged with feet, and the lower end of the lower leg member Also hinged to the upper end of the foot.

The present invention also includes such structural features:

1. The two left and right leg mechanisms in the four groups of leg mechanisms are arranged oppositely.

2. Each foot is also provided with a shock-absorbing spring device.

Compared with the prior art, the invention has the advantages of simple structure, easy control, good dynamic walking ability and low cost. The invention mainly adopts a planar six-bar linkage mechanism and a gear transmission, realizes the straight-line walking and turning walking functions of the robot, greatly simplifies the mechanical structure of the robot and is convenient to control. The legged robot has the advantages of good maneuverability and high stability. At the same time, the quadruped walking robot is equipped with a shock absorbing device, which can realize smooth movement on complex road surfaces. The invention imitates the horse's diagonal trotting posture, that is, when the two legs on the diagonal line of the robot are used as the support phase, the other two legs are used as the swing phase, and the four legs complete the step action in pairs to form a gait cycle.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the present invention;

Fig. 2 is the schematic diagram of the top view direction of the present invention;

Fig. 3 is a schematic diagram of the main viewing direction of the present invention;

Fig. 4 is a schematic structural view of the side view direction of the present invention;

Fig. 5a is a schematic diagram of the front view direction of the leg mechanism of the present invention, and Fig. 5b is a schematic structural diagram of the side view direction of the leg mechanism of the present invention;

Fig. 6 is a schematic structural view of the motor assembly of the leg mechanism of the present invention;

Fig. 7 is a schematic structural view of the turning mechanism of the present invention;

Fig. 8 is the trotting motion analysis diagram of the robot of the present invention;

Fig. 9 is a schematic diagram of turning of the robot of the present invention.

In the figure: 1 frame, 2 turning mechanism, 3 lower body, 4 leg mechanism, 201 is a flange, 202 is a cylindrical pin, 203 is a rolling bearing, 204 is a shaft sleeve 1, 205 is a large bevel gear shaft, 206 is Bottom cover, 207 is the shaft sleeve 2, 208 is the angular contact ball bearing, 209 is the small bevel gear shaft, 210 is the flange coupling, 211 is the motor mounting seat, 212 is the reducer, 213 is the DC coreless servo motor, 214 is an encoder; 401 is a foot, 402 is a shock absorber, 403 is a thigh rod, 404 is a calf rod, 405 is a thigh connecting rod, 406 is a crank, 407 is a servo motor, and 408 is a flange coupling device, 409 is a motor mount.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Figure 1, Figure 2, Figure 3, and Figure 4 show a planar linkage quadruped walking robot imitating the gait of a horse. The robot consists of a frame 1, a turning mechanism 2, a lower body 3 and four legs with the same structure. Mechanism legs A-D are composed. The turning mechanism 2 and the leg mechanism 4 are arranged at the four corners of the frame 1, which are left-right symmetrical. The turning mechanism 2 is mainly composed of a servo motor 213, a shaft coupling 210 and straight bevel gears 205, 209, which are fixed on the frame 1, and The lower body 3 is connected through flange structures 201 and 202; the leg mechanism 4 is composed of a thigh mechanism and a lower leg mechanism, and adopts a planar six-bar linkage mechanism, wherein the thigh mechanism adopts a crank rocker mechanism 403-406, and the lower leg mechanism adopts double rockers Mechanisms 402-405; the leg mechanism 4 is provided with a shock-absorbing device 402; by imitating the gait of a horse, the legs are linked on the diagonal, so that the robot can move smoothly in all directions.

Figure 5a and Figure 5b show the leg mechanism 4 of the robot. The leg mechanism 4 is composed of a thigh mechanism and a lower leg mechanism, and adopts a planar six-bar linkage mechanism, wherein the thigh mechanism adopts crank rocker mechanisms 403-406, and the lower leg mechanism adopts double The rocker mechanism 402-405; the leg mechanism 4 is provided with a shock-absorbing device 402, through imitating a horse's gait, the legs are linked on the diagonal, so that the robot can move smoothly in all directions. The motor 407 drives the crank 406 to realize full rotation, and drives the thigh rod 403 and the thigh connecting rod 405 to swing; That is, the connecting rod driven by the crank 406 acts as a rocker to drive the swing of the calf; when the crank 406 is passively rotated for a full circle, the calf will realize the cyclic action of stepping forward and kicking the ground backward.

According to the needs of the structure, the lower body 3 is determined to be a fixed link with a length of L ₁ , the length of the thigh rod 403 is L ₂ , the length of the crank 406 is L ₃ , and the length of the thigh link 405 is L ₄ . The relationship between L ₃ and L ₄ can be obtained by applying two limit positions, and then the size of each connecting rod can be obtained. At the same time, the phase difference between the two cranks 406 of the left and right legs of the robot is always 15°. Due to the linkage of the legs, that is, when one leg reaches the front position, the other leg has reached the last position, so as long as the cranks of the left and right legs The mechanism forms an included angle of 150°-15°=135°.

Fig. 6 shows the structural details of the motor unit. Each leg of the robot is independently driven by a servo motor 407, and the servo motor 407 is installed on the motor mounting base 409, through the rotation of the flange coupling 408 and the crank 406. The shafts are connected, and then the servo motor 407 can drive the crank 406 to move around. The connecting rod driven by the crank 406 is used as a rocker to drive the swing of the lower leg, thereby realizing continuous actions of stepping forward and kicking the ground backward.

The robot should not only realize the function of walking in a straight line, but also realize the function of turning and walking. The turning mechanism 2 of the robot is shown in FIG. 6 . The turning mechanism 2 is driven by a straight-toothed bevel gear. The turning mechanism 2 can not only directly use the motor 213 to drive the straight-toothed bevel gear and then drive the transmission shaft to rotate to realize the turning motion of the robot, but also is a connecting mechanism between the robot leg and the lower body.

The turning and walking function of the present invention is mainly realized by the turning mechanism 2 . Each turning mechanism 2 is independently driven by a DC hollow cup servo motor 213, which is driven by a straight bevel gear. The input end is a small bevel gear shaft 209, and the output end is a large bevel gear shaft 205. The servo motor 213 is installed on the motor mounting base. 211, the motor mount 211 is fixed on the frame 1 through bolt connection, the output shaft of the servo motor 213 is connected with the pinion bevel gear shaft 205 through the flange type coupling 210, and the pinion bevel gear shaft 205 is through the angular contact ball bearing 208 Fixed, the small bevel gear shaft 205 and the large bevel gear shaft 209 are vertically installed alternately, the large bevel gear shaft 209 is fixed by the rolling bearing 203, and the rolling bearing 203 is positioned by the sleeve 1204, the top of the large bevel gear shaft 209 is sealed by the stuffy cover 206, and the bottom is passed through The flange 201 and the cylindrical pin 202 are connected with the lower body 3 , and the rotation thereof can drive the robot leg mechanism 4 to rotate as a whole, and the rotation angle is controlled by the encoder 214 .

Each leg of the robot is designed with a shock-absorbing device 402 to realize the smooth movement of the robot in complex environments. The shock absorber 402 adopts a spring shock absorber, and the two ends are respectively connected with the foot 401 and the thigh bar 403 through bolts. Modular design, can adopt hydraulic shock absorber or hybrid shock absorber, not limited to spring shock absorber, easy to repair and replace as needed.

The quadruped walking robot of the present invention imitates the diagonal trotting posture of a horse, that is, when the two legs on the diagonal of the robot are used as the support phase, the other two legs are used as the swing phase, and the four legs complete the stepping action in pairs to form a gait cycle.

When the robot walks on a relatively smooth road, only the leg motor 407 drives the crank 406 to move, so as to realize the walking of the robot. The straight-line walking gait of the robot is the diagonal trotting posture of the pony, and the specific process is as follows:

(1) The initial pose is shown in the first picture of Figure 8, and the four legs stand on the ground as the supporting phase at the same time;

(2) When starting to take a step, the right front leg C and the left rear leg A step forward, and at the same time the left front leg B and the right rear leg D push back to achieve the first step;

(3) When the right front leg C and the left rear leg A touch the ground again, the left front leg B and the right rear leg D start to move forward, and the right front leg C and the left rear leg A push the ground backward;

(4) The four legs complete the stepping action in pairs, forming a gait cycle.

When the robot encounters a larger obstacle and cannot cross it, the leg swivel motor 213 of the corresponding swing phase drives the bevel gear 209 to rotate during the leg lifting process, so that the legs of the robot are driven by the drive shaft to turn. Rotate the corresponding angles in sequence. When avoiding obstacles, the motor 213 reverses the corresponding angles in turn to reset the robot, and then continues to walk forward in a straight line. The specific process is shown in Figure 9, which can be described as:

(1) The left front leg C and the right rear leg A turn at a certain angle when they step forward;

(2) When the right front leg D and the left rear leg B step forward, they also turn the same angle;

(3) After avoiding the obstacle, the motor reverses the same angle when the right front leg D and the left rear leg B step forward, and the left front leg C and the right rear leg A also reverse the same angle when stepping forward.

(4) Turning can be realized in one gait cycle like this, which is fast and convenient.

Claims (3)

1. the planar linkage formula four feet walking robot of a kind of imitative equine gait, it is characterised in that：Including double-deck frame, it is arranged on The lower body of four groups of turning mechanisms and each turning mechanism lower end connection in frame and the lower limb being arranged on each lower body Portion mechanism, every group of turning mechanism includes rack-mounted DC hollow cup servomotor and DC hollow cup servomotor The decelerator of outfan connection and small coning gear shaft, the small bevel gear on small coning gear shaft of the connection of decelerator outfan Wheel, the large bevel gear shaft being vertically arranged in frame, the bevel gear wheel on large bevel gear shaft, bevel pinion and auger tooth Wheel engagement；Each lower body is connected with the lower end of corresponding large bevel gear shaft, and each leg mechanism includes being arranged on body Thick link and thick link end that servomotor and the crank and crank end of the connection of servo motor output shaft end are hinged The interposition of the shank rod member that the thigh rod member and thick link centre position that portion is hinged is hinged, thick link and thigh rod member Put and be hinged, the upper end of thigh rod member is hinged on lower body, the lower end of thigh rod member is hinged with foot, the lower end of shank rod member It is hinged with the upper end of foot.

2. the planar linkage formula four feet walking robot of a kind of imitative equine gait according to claim 1, it is characterised in that：Institute Two leg mechanisms for stating the left side in four groups of leg mechanisms and the right are oppositely arranged.

3. a kind of planar linkage formula four feet walking robot of imitative equine gait according to claim 1 and 2, its feature exists In：Damping spring device is additionally provided with each foot.