CN201633803U - Hydraulically Driven Quadruped Robot Mobile Mechanism with Center of Mass Adjustment Device - Google Patents

Abstract

The utility model relates to a hydraulically driven quadruped robot moving mechanism with a center of mass adjusting device, which comprises a trunk, a moving frame, a center of mass adjusting device and four robot legs. connect. The utility model has the following characteristics: (1) hydraulic drive is adopted, so that the robot has greater load-bearing capacity; (2) each leg has four active joints, with redundant degrees of freedom, so that the robot has a stronger complex terrain environment Adaptability and obstacle-surmounting ability; (3) It has a center of mass adjustment device and does not require additional counterweights, which makes the robot more stable; (4) The 16 active joints of the robot are driven by exactly the same hydraulic servo cylinders, making the robot structure Simpler and easier to maintain. The utility model is suitable for the transportation of military and civilian materials, anti-terrorism equipment, field exploration and exploration, planetary detection, agricultural production and the like under complex terrain environments.

Description

Hydraulically Driven Quadruped Robot Mobile Mechanism with Center of Mass Adjustment Device

technical field

The utility model relates to a quadruped robot moving mechanism, in particular to a hydraulically driven quadruped robot moving mechanism with a centroid adjusting device.

Background technique

At present, the commonly used mobile modes of ground mobile robots are mainly wheeled, crawler, peristaltic, crawling and walking. The wheeled mobile mechanism has the advantages of small frictional resistance and fast speed, but it is only suitable for a relatively flat ground environment, and its ability to overcome obstacles is poor. The crawler-type mobile mechanism has strong adaptability to the terrain environment, and can climb over obstacles, climb stairs, and cross trenches, etc., but the transmission efficiency is low. Creeping, crawling and walking are all bionic movement methods that imitate animals. They have strong adaptability to the terrain environment and can walk on most ground environments, and the walking method has the fastest movement speed. Walking quadruped robots have broad application prospects in military material transportation in complex terrain environments, anti-terrorism equipment chassis, field exploration and exploration, planetary exploration, and agricultural production.

In 1968, the United States developed the world's first four-legged walking robot with control functions in the modern sense by Mosher of General Electric Company. In 1977, Robert McGhee of Ohio State University developed the world's first digital computer-controlled walking bionic robot. Since the 1980s, research institutions in the United States, Japan, Canada, Switzerland, Germany and other countries have all begun to study walking quadruped mobile robots that imitate mammals, and many other institutions have studied multi-legged mobile robots that imitate reptiles.

Chinese patent document ZL200820157956.2 discloses "a walking mechanism for a quadruped walking robot". The robot has a set of bipedal drive components and walking legs symmetrically arranged on the front, rear, left and right sides of the frame, and each leg has One degree of freedom for oscillation in the horizontal plane and one degree of freedom for oscillation in the vertical plane. The moving mechanism of the quadruped robot can only realize static walking, and the movement speed is slow; each leg has only two degrees of freedom, the movement space is small, and the ability to overcome obstacles is poor.

Chinese patent document CN101602382A discloses "a single-drive quadruped walking robot". The robot is equipped with two parallel rotating shafts at the front and rear, driven by a motor through a transmission element, and the left and right ends of each rotating shaft are fixedly connected to cranks. . The robot is equipped with four single legs, and each leg is hinged by a crank swing mechanism and a crossed parallelogram in series, and is driven by a connecting crank at each shaft end. The robot is driven by a single motor to walk, but the four legs are all mechanically connected by connecting rods, and the movement law between the legs is fixed. It can only walk on flat ground, does not have the ability to overcome obstacles, and can only go straight. Can't turn.

Chinese patent document ZL03153505.4 discloses "an adjustable quadruped bionic robot motion structure", which mainly includes a top reference plate, four legs, four feet, a driving device and a sensing device. Four adjustment slots are symmetrically opened on the top reference plate for the four legs to move back and forth, and a hoisting structure is adopted between the four legs and the top reference plate; the thigh and calf are driven by their respective driving devices to swing along their respective joint axes. The robot can realize typical gaits such as free walking, diagonal walking, side step, running, etc., can turn, and has the ability to climb slopes and overcome obstacles. Each leg of the robot has two joints, the dynamic range of the leg length is small, and the ability to adapt to complex terrain environments and overcome obstacles is limited; it is driven by a motor, and its dynamic response and load capacity are poor.

Contents of the invention

The purpose of this utility model is to overcome the shortcomings of the above-mentioned prior art, and provide a hydraulically driven quadruped with a center of mass adjustment device that is simple in structure, capable of overcoming obstacles, capable of steering, strong in load capacity, easy to maintain, and strong in dynamic response. Robot mobile mechanism.

In order to achieve the above object, the utility model adopts the following technical solutions:

A hydraulically driven quadruped robot moving mechanism with a center of mass adjustment device, which includes a torso, a mobile frame, a center of mass adjustment device and four robot legs, the lower part of the torso is provided with four robot legs, and the upper part of the torso is connected to the mobile frame through a center of mass adjustment device .

Each of the robot legs is composed of three successively connected leg sections and a lower leg. The lower leg is arranged at the lower part of the three-section leg sections, and the three-section leg sections and between the leg sections and the lower legs are all rotated along the transverse direction of the torso through the axis. The pair is connected with the servo cylinder, and the uppermost leg joint is connected with the torso through the rotating pair whose axis is along the longitudinal direction of the trunk. The aforementioned four rotating pairs are four active joints of each leg; the lower part of the lower leg is provided with a passive telescopic joint.

The shank includes a shank outer cylinder. A high-pressure air bag is installed at the upper end of the shank outer cylinder, and two linear bearings are installed at the lower end. A shank telescopic rod is installed in the inner hole of the linear bearing. A rubber sleeve is installed at the lower end of the shank telescopic rod. There are six-dimensional force sensors.

The servo cylinder includes a hydraulic cylinder, a servo valve, a displacement sensor and a force sensor, the force sensor is installed on the cylinder rod of the hydraulic cylinder, and the displacement sensor is installed on one side of the hydraulic cylinder.

The center-of-mass adjustment device includes a two-way nut bracket. The lower part of the two-way nut bracket is provided with a lateral movement device connected to the trunk, and the upper part is provided with a longitudinal movement device connected with the moving frame.

The lateral moving device includes a horizontal screw connected to the lower part of the two-way nut bracket through a screw pair. One end of the horizontal screw is provided with a connecting plate I, and the other end is connected to the DC motor I through a gear mechanism I. A connecting plate I is provided outside the gear mechanism I. Plate II.

The longitudinal moving device includes a longitudinal screw and an optical axis arranged in parallel, and the longitudinal screw and the optical axis are arranged on it through the helical pairs and the linear bearings on both sides of the upper part of the bidirectional nut bracket respectively; one end of the longitudinal screw is provided with a connecting plate III, The other end is connected with the DC motor II through the gear mechanism II, and the gear mechanism II is provided with a connection plate IV; the two ends of the optical axis are respectively provided with a connection plate III.

The torso is a rectangular frame.

The mobile frame is a frame with a trapezoidal cross section.

Each leg of the robot of the utility model has four active joints, so that the working space of the robot foot is larger, and it has stronger ability to adapt to complex terrain and overcome obstacles.

Four identical robot legs are installed symmetrically at the four corners of the lower torso. The front and rear legs can be installed in the same direction or reversely according to the knee joints. The upper torso is connected to the mobile frame through a center of mass adjustment device.

The mobile frame is a frame structure with a trapezoidal cross section, which is used to install and fix various sensors, control system modules, hydraulic system modules, etc., and can carry goods.

When the robot walks fast, the ground has a greater impact on the robot's feet, causing the calf telescopic rod to move upward relative to the outer cylinder of the calf, the high-pressure airbag is compressed, and at the same time absorbs the impact of the ground on the feet, which acts as a buffer and damping role. A six-dimensional force sensor is used to measure the force exerted by the ground on the foot. The rubber sleeve is used to increase the friction between the foot and the ground, protect the six-dimensional force sensor, and play a part of buffering and vibration reduction.

When the DC motor drives the horizontal lead screw through the gear mechanism, the bidirectional nut support drives the moving frame through the longitudinal lead screw to move laterally along the trunk. When the DC motor drives the longitudinal lead screw through the gear mechanism, the mobile frame can move longitudinally relative to the trunk.

Quadruped robots often use some kind of symmetrical gait when walking fast and dynamically. When the projection of the robot's center of mass on the ground is located at the centroid of the support area of the four legs, the kinematics and dynamics parameters of the two symmetrical legs are the same; At the same time, the dynamic parameters of the two symmetrical legs are different, which will increase the difficulty of robot stability control. The center of mass adjustment method is: on a flat ground, the four legs of the robot stand upright, and the adjustment direction is determined by the vertical component force measured by the six-dimensional force sensor on the feet of the four legs to the resultant moment of the centroid of the foot support area, and adjusted by the center of mass adjustment device Move the frame and all masses fixed to it until the resultant moment is zero.

The utility model has the following characteristics:

(1) Hydraulic drive is adopted to make the robot have greater load-bearing capacity;

(2) Each leg has four active joints, with redundant degrees of freedom, so that the robot has a stronger ability to adapt to complex terrain environments and overcome obstacles;

(3) It has a center of mass adjustment device and does not require additional counterweights, making the robot more stable;

(4) The 16 active joints of the robot are driven by the same hydraulic servo cylinder, which makes the structure of the robot simpler and easier to maintain.

The utility model is suitable for the transportation of military and civilian materials, anti-terrorism equipment, field exploration and exploration, planetary detection, agricultural production and the like in complex terrain environments.

Description of drawings

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

Figure 2 is a schematic diagram of the composition of a leg of the robot;

Fig. 3 is the front view that robot leg is connected with torso;

Fig. 4 is a schematic diagram of the composition of the hydraulic servo cylinder;

Fig. 5 is a schematic diagram of the structure of the robot's lower leg;

Figure 6 is an exploded view of the assembly of the robot torso, the center of mass adjustment device and the mobile frame;

Figure 7 is a schematic diagram of the composition of the center of mass adjustment device;

In the figure: 1. Mobile frame, 2. Center of mass adjustment device, 3. Trunk, 4. Robot leg, 5. Leg section Ⅰ, 6. Servo cylinder, 7. Rotary joint Ⅰ, 8. Leg joint Ⅱ, 9. Rotary joint Ⅱ, 10. Leg section Ⅲ, 11. Revolving pair Ⅲ, 12. Lower leg, 13. Moving pair, 14. Revolving pair Ⅳ, 15. Hydraulic cylinder, 16. Electro-hydraulic servo valve, 17. Displacement sensor, 18. Force sensor , 19. Calf outer cylinder, 20. Air bag, 21. Linear bearing, 22. Calf telescopic rod, 23. Six-dimensional force sensor, 24. Rubber sleeve, 25. Connecting plate Ⅳ, 26. Gear mechanism Ⅱ, 27. DC motor Ⅱ, 28. Longitudinal screw, 29. Two-way nut bracket, 30. Connecting plate Ⅲ, 31. Connecting plate Ⅱ, 32. Gear mechanism Ⅰ, 33. DC motor Ⅰ, 34. Optical axis, 35. Transverse screw, 36 . Connecting plate Ⅰ.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

As shown in FIG. 1 , the utility model includes a torso 3 , a mobile frame 1 , a center of mass adjustment device 2 and four robot legs 4 . The lower part of the torso 3 is provided with four robot legs 4 , and the upper part of the torso 3 is connected with the mobile frame 1 through the center of mass adjustment device 2 .

Each robot leg is composed of three leg segments (leg segment I5, leg segment II8, and leg segment III10) and a lower leg 12 (see Figure 2). The lower leg 12 is set at the lower part of the three leg segments. The longitudinal rotation joint IV14 of the torso is connected with the trunk 3 (see Fig. 3), and the joints between the leg segment I5 and the leg segment II8, the leg segment II8 and the leg segment III10, and the leg segment III10 and the lower leg 12 are all passed through the axis along the lateral rotation joint of the trunk ( Rotating pair I7, rotating pair II9 and rotating pair III11 (see Figure 2) are connected, the above four joints (namely the aforementioned four rotating pairs) are all driven by the servo cylinder 6, and the calf 12 has a passive telescopic joint. Each leg of the robot has four active joints (rotation joint Ⅰ7, rotation joint Ⅱ9, rotation joint Ⅲ11 and rotation joint Ⅳ14), which makes the working space of the robot foot larger, and has stronger ability to adapt to complex terrain and overcome obstacles.

As shown in FIG. 5 , the robot lower leg 12 is composed of a lower leg outer tube 19 , an air bag 20 , a linear bearing 21 , a lower leg telescopic rod 22 , a six-dimensional force sensor 23 and a rubber sleeve 24 . A high-pressure air bag 20 is installed on the upper end of the shank outer cylinder 19, and two linear bearings 21 are installed on the lower end. The inner hole of the linear bearing is equipped with a shank telescopic rod 22, and the lower end of the shank telescopic rod 22 is equipped with a rubber sleeve 24. Six-dimensional force sensor 23.

When the robot walks fast, the ground has a greater impact on the robot’s feet, causing the calf telescopic rod 22 to move upward relative to the calf outer cylinder 19, and the high-pressure airbag 20 is compressed, and at the same time absorbs the impact of the ground on the feet to play a buffer role. and damping effect. The six-dimensional force sensor 23 is used to measure the force exerted by the ground on the foot. The rubber sleeve 24 is used to increase the friction between the foot and the ground, protect the six-dimensional force sensor 23, and play a part of buffering and vibration reduction.

As shown in Figure 4, the servo cylinder 6 is made up of a hydraulic cylinder 15, an electro-hydraulic servo valve 16, a displacement sensor 17 and a force sensor 18. side.

The centroid adjustment device 2, as shown in Figure 7, includes a bidirectional nut support 29, the bottom of which is provided with a lateral movement device connected to the trunk 3, and the top is provided with a longitudinal movement device connected with the mobile frame 1.

The lateral moving device includes a horizontal screw 35 connected to the lower part of the two-way nut bracket 29 through a screw pair. One end of the horizontal screw 35 is provided with a connecting plate I36, and the other end is connected with a DC motor I33 through a gear mechanism I32. The outside of the gear mechanism I32 is provided with Connection plate II31.

The longitudinal moving device comprises a longitudinal screw 28 and an optical axis 34 arranged in parallel, and the longitudinal screw 28 and the optical axis 34 are arranged on it by screw pairs and linear bearings on both sides of the top of the two-way nut support 29 respectively; one end of the longitudinal screw 28 is provided with The other end of the connection plate III30 is connected with the DC motor II27 through the gear mechanism II26, and the outside of the gear mechanism II26 is provided with the connection plate IV25; the two ends of the optical axis are respectively provided with the connection plate III30.

The horizontal lead screw 35 is fixedly connected with the trunk 3 through the connecting plate II 31 and the connecting plate I 36 , and the horizontal lead screw 35 is connected with the lower part of the two-way nut bracket 29 through a screw pair. The upper part of the two-way nut bracket 29 is connected to the longitudinal lead screw 28 through a screw pair, and connected to the optical axis 34 through a linear bearing.

When the DC motor I33 drives the horizontal lead screw 35 through the gear mechanism I32, the bidirectional nut bracket 29 drives the moving frame 1 through the longitudinal lead screw 28 and the optical axis 34 to move laterally along the trunk 3. When the DC motor II 27 drives the longitudinal lead screw 28 through the gear mechanism II 26 , the moving frame 1 can move longitudinally relative to the trunk 3 .

Quadruped robots often use some kind of symmetrical gait when walking fast and dynamically. When the projection of the center of mass of the robot on the ground is located at the centroid of the support area of the four legs, the kinematics and dynamics parameters of the two symmetrical legs are the same; when the projection of the center of mass of the robot on the ground is not located at the centroid of the support area of the four legs , the dynamic parameters of the two symmetrical legs are different, which will increase the difficulty of robot stability control. The center of mass adjustment method is: on a flat ground, the four legs of the robot are upright, and the adjustment direction is determined according to the resultant moment of the vertical component force measured by the six-dimensional force sensor 23 of the feet of the four legs on the centroid of the foot support area, and adjusted by the center of mass adjustment device 2 Move frame 1 and all masses fixed on it until the resultant moment is zero.

The torso 3 is a rectangular frame (see Figure 6), and four identical robot legs 4 are installed symmetrically at the four corners of the lower part of the torso 3. The upper part of the torso 3 is connected with the mobile frame 1 through the center of mass adjustment device 2 .

The mobile frame 1 is a frame structure with a trapezoidal cross section (see Figure 6), which is used to install and fix various sensors, control system modules, hydraulic system modules, etc., and can carry goods.

Claims (9)

1. A hydraulically driven quadruped robot moving mechanism with a center of mass adjustment device is characterized in that: it comprises a trunk, a mobile frame, a center of mass adjustment device and four robot legs, the bottom of the trunk is provided with four robot legs, and the upper part of the torso passes through the center of mass The adjustment device is connected with the mobile frame. 2. The moving mechanism of a hydraulically driven quadruped robot with a center of mass adjustment device according to claim 1, wherein each robot leg is composed of leg joints and shanks connected in sequence in three sections, and the shanks are arranged in three sections The lower part of the leg section, the three leg sections and the leg section and the lower leg are all connected by a rotary joint whose axis is along the horizontal direction of the trunk and a servo cylinder. The uppermost leg section is connected with the trunk by a rotary joint whose axis is along the longitudinal direction of the trunk. The aforementioned The four rotating pairs are four active joints of each leg; the lower part of the lower leg is provided with a passive telescopic joint. 3. The moving mechanism of a hydraulically driven quadruped robot with a center of mass adjustment device according to claim 2, wherein the shank includes a shank outer cylinder, a high-pressure air bag is installed at the upper end of the lower leg outer cylinder, and two straight lines are installed at the lower end. Bearing, linear bearing inner hole is equipped with shank telescopic rod, and the lower end of shank telescopic rod is equipped with rubber sleeve, is provided with six-dimensional force sensor in the rubber sleeve. 4. The hydraulically driven quadruped robot moving mechanism with a center of mass adjustment device according to claim 2, characterized in that: the servo cylinder includes a hydraulic cylinder, a servo valve, a displacement sensor and a force sensor, and the force sensor is installed on the hydraulic cylinder On the cylinder rod, the displacement sensor is installed on one side of the hydraulic cylinder. 5. The hydraulically driven quadruped robot moving mechanism with a center of mass adjustment device according to claim 1, wherein the center of mass adjustment device comprises a two-way nut support, the lower part of the two-way nut support is provided with a lateral movement device connected to the trunk, The upper part is provided with a longitudinal moving device connected with the moving frame. 6. The moving mechanism of a hydraulically driven quadruped robot with a center of mass adjustment device according to claim 5, characterized in that: said lateral movement device comprises a horizontal lead screw connected to the bottom of the two-way nut bracket through a screw pair, one end of the horizontal lead screw A connecting plate I is provided, and the other end is connected with a DC motor I through a gear mechanism I, and a connecting plate II is arranged outside the gear mechanism I. 7. The hydraulically driven quadruped robot moving mechanism with a center of mass adjustment device according to claim 5, characterized in that: said longitudinal movement device includes a longitudinal lead screw and an optical axis arranged in parallel, and the longitudinal lead screw and the optical axis respectively pass through a two-way nut The screw pairs and linear bearings on both sides of the upper part of the bracket are arranged on it; one end of the longitudinal screw is provided with a connection plate III, and the other end is connected with the DC motor II through a gear mechanism II, and the outside of the gear mechanism II is provided with a connection plate IV; Both ends of the shaft are respectively provided with connecting plates III. 8. The moving mechanism of a hydraulically driven quadruped robot with a center of mass adjustment device according to claim 1, wherein said torso is a rectangular frame. 9 . The hydraulically driven quadruped robot moving mechanism with a center of mass adjustment device according to claim 1 , wherein the moving frame is a frame with a trapezoidal cross section. 10 .

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