CN103009401B - Mechanical arm, control method of mechanical arm and robot - Google Patents

Abstract

A mechanical arm, a control method of the mechanical arm and a robot. The present invention relates to the field of automatic control, and provides a mechanical arm, which includes at least one servo motor, a closed air bag, and at least one rope. The air bag includes at least one joint. A servo motor is connected, and the attitude of the joint is controlled by adjusting the length of the rope through the servo motor. In a preferred embodiment, the mechanical arm includes at least two ropes, one end of each rope is connected to the end of one of the joints, the other end is connected to one of the servo motors, and each joint is controlled by at least two ropes, each joint The length control of each rope is coupled with each other to control the posture of the joint. The invention provides a mechanical arm with high safety. The mechanical arm is supported by an air bag and driven by a cable, thereby greatly reducing the inertia of the mechanical arm and increasing the compliance of the mechanical arm, making the use of the mechanical arm easier. Safer and more beautiful.

Description

A kind of mechanical arm, the control method of mechanical arm and robot

technical field

The invention relates to the field of automatic control, and more specifically, relates to a mechanical arm, a control method of the mechanical arm and a robot.

Background technique

A robotic arm is an automatic control device that mimics the functions of a human arm and can perform various tasks. The robot system composed of such a robotic arm is connected by multiple joints and allows movement in two-dimensional or three-dimensional space or using linear displacement.

In the conventional prior art, the mechanical arm is generally made of some very rigid materials such as metal, and the driving motors are directly installed on the mechanical arm, so the inertia of the mechanical arm will be large and lack in the case of open-loop control. Compliance makes it more difficult to control the robotic arm during the design process. In addition, when the mechanical arm made of metal is in contact with people or other objects or when it is working, it is easy to cause greater injuries due to collisions. The collision problem of manipulators is more important in the field of service robots, because there are many uncertainties in the working environment and the need to interact with people frequently, which increases the risk of unexpected collisions. In response to this problem, the publication date is August 7, 2012, and the U.S. authorized invention patent with the publication number US8234949 proposes to drive the joints of the mechanical arm by means of steel wire transmission, and its servo motor can be installed on the base of the mechanical arm to reduce the mechanical arm The moment of inertia in motion. However, the structural parts of this type of robotic arm are still made of rigid materials, so there is still a certain degree of collision damage.

Contents of the invention

The purpose of the present invention is to solve the problem of insufficient safety of the mechanical arm in the prior art in the process of serving robots, and provide a mechanical arm with high safety, which is supported by an airbag and driven by a cable, thereby The inertia of the mechanical arm is greatly reduced and the compliance of the mechanical arm is increased, making the use of the mechanical arm safer and more beautiful.

In order to achieve the above object, the present invention provides a mechanical arm on the one hand, the mechanical arm includes at least one servo motor, a closed air bag, at least one rope, the air bag includes at least one joint, and the cross-sectional area of the joint position is smaller than that of other positions of the air bag Cross-sectional area, one end of each rope is connected to the end of one of the joints, and the other end is connected to one of the servo motors, and the attitude of the joint is controlled by adjusting the length of the rope through the servo motor.

According to one embodiment of the present invention, the mechanical arm includes at least two ropes, one end of each rope is connected to the end of one of the joints, the other end is connected to one of the servo motors, and each joint is controlled by at least two ropes, each The length control of each rope of each joint is coupled with each other to control the posture of the joint.

According to an embodiment of the present invention, the mechanical arm comprises at least two servo motors, each servo motor independently controlling a rope.

According to one embodiment of the present invention, the mechanical arm also includes sleeves for nesting ropes, the sleeves are all arranged inside the airbag, the inlet of each sleeve is fixed at the top of one of the joints, and its outlet is fixed at the top of the mechanical arm. the roots.

According to an embodiment of the present invention, the airbag includes at least two joints connected together, and the connection mode of the joints is a tree connection mode or a series connection mode.

According to an embodiment of the present invention, the joint includes a single-degree-of-freedom joint, the single-degree-of-freedom joint is controlled by two cables, and the positions of the two cables are equally divided by 180 degrees in the cross section of the joint.

According to one embodiment of the present invention, the joint comprises a two-degree-of-freedom joint controlled by at least three cables, and the positions of the cables in the two-degree-of-freedom joint are combined at an angle of less than 180 degrees in the cross-section of the joint divided.

According to an embodiment of the present invention, the position of each rope in the two-degree-of-freedom joint is equally divided by the number of ropes in the cross section of the joint.

According to one embodiment of the present invention, the mechanical arm includes an air pump for inflating the air bag, an air pressure sensor for detecting air pressure, and an air pressure controller for receiving air pressure instructions, and the air pressure controller receives the air pressure instructions and the air pressure signals sent by the air pressure sensor. After the pressure signal, the air pump controls the air pressure in the air bag to make the air pressure consistent with the air pressure command; the robotic arm also includes an attitude controller, which is used to control the servo motor to adjust the length of the rope to control the attitude of the joint.

According to another aspect of the present invention, a method for controlling a mechanical arm is provided, comprising the following steps:

Send air pressure commands to the air pressure controller, and the air pressure sensor detects the air pressure and sends out a pressure signal;

After the air pressure controller receives the air pressure command and pressure signal, the air pump inflates the air bag, and the air pressure in the air bag is controlled by the air pump or the air valve on the air bag so that the air pressure is consistent with the air pressure command;

After adjusting the air pressure in the airbag, issue an attitude command;

The attitude controller receives the attitude instruction, and controls each servo motor to adjust the length of each rope according to the attitude instruction, so that the attitude of the joint controlled by the rope is consistent with the attitude instruction.

According to still another aspect of the present invention, a robot is provided, including the mechanical arm described in the above technical solution.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The mechanical arm of the present invention adopts a closed non-stretchable air bag to support the mechanical arm, which greatly reduces the harm caused by the collision of the mechanical arm with other contact objects during the working process, and ensures that the mechanical arm Work safety, in addition, this kind of mechanical arm can shrink the airbag when it is not working, which reduces the occupied space of the mechanical arm and is easy to carry and transport;

(2) The mechanical arm of the present invention adopts a multi-joint mechanical arm design, wherein the joints are controlled independently of each other, and do not need to be adjusted accordingly by the activities of other joints. When the multi-section joints are properly combined, they have a height Mimics the mobility of the human arm;

(3) The joints adopted by the mechanical arm of the present invention can have multiple degrees of freedom, that is, a single joint can be controlled by multiple ropes, and the joints formed in this way are more flexible than single-degree-of-freedom joints in the prior art. More complex activities, and ultimately realize more functions of the robot;

(4) The robot arm of the present invention arranges all the ropes inside the airbag, which makes the control process of the robot arm more concise, and avoids the appearance of the robot arm being affected by the exposure of a large number of ropes to the robot arm, making the robot using this kind of robot arm more beautiful .

(5) The wiring of the sleeve of the present invention passes through the inside of the joint, especially through the center, which can greatly reduce the length of the sleeve that needs to be reserved due to joint movement.

Description of drawings

FIG. 1 is a schematic structural view of a mechanical arm according to a first embodiment of the present invention;

2 is a schematic structural view of a mechanical arm according to a second embodiment of the present invention;

Fig. 3 is a schematic diagram of the tree connection mode of multi-segment joints of the present invention;

Fig. 4 is a schematic diagram of the ring-shaped connection mode of the multi-segment joint of the present invention;

Fig. 5 is a schematic diagram of the serial connection mode of multi-segment joints of the present invention;

Fig. 6A is a top view of the rope distribution of the two-degree-of-freedom joint of the present invention;

Fig. 6B is a front view of the rope distribution of the two-degree-of-freedom joint of the present invention;

Fig. 6C is a side view of the rope distribution of the two-degree-of-freedom joint of the present invention;

Fig. 7A is a top view of the rope distribution of the single-degree-of-freedom joint of the present invention;

Fig. 7B is a front view of the rope distribution of the single-degree-of-freedom joint of the present invention;

Fig. 7C is a side view of the rope distribution of the single-degree-of-freedom joint of the present invention;

Fig. 8 is a schematic diagram of the movement of the mechanical arm joint of the present invention;

Fig. 9 is a schematic structural view of the air pressure control system of the present invention;

Fig. 10 is a structural schematic diagram of the attitude control system of the present invention;

Fig. 11 is a schematic flowchart of the control method of the manipulator of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

As shown in Figure 1, in the first embodiment of the present invention, the mechanical arm includes at least one servo motor 10, an air pump 21 for inflating the airbag, an air valve 22 for releasing the airbag in a non-working state, The air pressure sensor 23 that detects air pressure, the closed air bag 30 and at least one rope 40, wherein the air pump 21, the air valve 22 and the air pressure sensor 23 form an inflation pipeline for adjusting the air pressure inside the air bag 30, and the inflation pipeline is arranged near the root of the mechanical arm. The airbag 30 includes at least one joint connected together, such as the first joint GJ1 in FIG. 1 , the second joint and the third joint that are not shown in FIG. One end of each rope 40 is connected to the end 401 of one of the joints, and the other end is connected to one of the servo motors 10. The length of the rope 40 is adjusted by the servo motor 10 to control the posture of the joint. When the servo motor 10 tightens the rope At 40, the joint moved to one side, and when the servo motor 10 loosened the rope 40, the joint returned to its original position. All the ropes are all arranged in the inside of the airbag 30, and the mechanical arm of the present invention also includes a plurality of sleeves 50 for nesting the ropes 40, wherein only one rope 40 is nested in each sleeve 50, and the sleeves 50 can Bending, but its cross-sectional area does not change during the working process, mainly to ensure the smooth stretching of the rope 40 . In the present invention, by arranging the servo motor 10 at the root of the mechanical arm, the inertia of the mechanical arm is reduced, making the mechanical arm easier to control and operate.

As shown in Figure 2, in the second embodiment of the present invention, the mechanical arm includes at least two servo motors 10, an air pump 21 for inflating the airbag, an air valve 22 for releasing the airbag in a non-working state, The air pressure sensor 23 for detecting the air pressure, the closed air bag 30 and at least two ropes 40, wherein the air pump 21, the air valve 22 and the air pressure sensor 23 constitute an inflation pipeline for adjusting the internal air pressure of the air bag 30, and the inflation pipeline is arranged at the root of the mechanical arm Nearby, the airbag 30 includes at least two joints that are connected together, for example, the first joint GJ1 and the second joint GJ2 in FIG. 2 , and the third joint and the fourth joint that are not shown in FIG. Each joint is controlled by at least two ropes, wherein one end of each rope 40 is connected to the end 401 of one of the joints, and the other end is connected to one of the servo motors 10, and each joint is controlled by at least two ropes, each The length control of each rope of each joint is coupled with each other to control the posture of the joint. All the ropes are all arranged in the inside of the airbag 30, and the mechanical arm of the present invention also includes a plurality of sleeves 50 for nesting the ropes 40, wherein only one rope 40 is nested in each sleeve 50, and the sleeves 50 can Bending, but its cross-sectional area does not change during the working process, mainly to ensure the smooth stretching of the rope 40 . In the present invention, by arranging the servo motor 10 at the root of the mechanical arm, the inertia of the mechanical arm is reduced, making the mechanical arm easier to control and operate.

In the above two embodiments, the airbag 30 is made of non-stretchable or low-stretch material, the airbag 30 is inflated by the air pump 21, and the air pressure sensor 23 is installed in the inflation pipeline to detect the air pressure. As shown in Figure 2, the cross-section of the joint position will be made smaller than other positions, so that the position at the joint can be bent more easily. All the ropes among the present invention are made of inextensible materials, wherein the rope 40 passes through the sleeve 50, the inlet 502 of the sleeve 50 is fixed on the top of the joint, and the outlet 501 of the sleeve 50 is fixed on one side of the entire mechanical arm, as root position. The sleeve 50 is made of a material that can only bend, not change its cross-sectional shape. The position of the outlet 501 of the casing 50 is fixed at a distance from the servo motor 10, so that the length of the rope pulled out by the servo motor 10 is consistent with the contracted length of the rope in the joint position. The combination of joints in the present invention can be composed of series connection, tree-like connection, ring-shaped connection or any combination of the above three connection methods, wherein the air paths between the joints are all connected, and the sleeve The tube 50 will pass through the center of the other joints and finally reach the root of the mechanical arm. Compared with running from the outside of the mechanical arm, the routing of the sleeve 50 through the center of the joint can greatly reduce the length of the sleeve 50 that needs to be reserved due to joint movement.

The principle and working method of the present invention are specifically described below by taking the second embodiment as an example:

The types of mechanical arm joints include universal (two-degree-of-freedom) joints and single-degree-of-freedom joints. Figures 6A to 6C show the structure of a two-degree-of-freedom joint, and Figures 7A to 7C show the structure of a single-degree-of-freedom joint. The two-degree-of-freedom joint is controlled by at least three ropes. In the case of using three ropes, one of the distributions is bisected by 120 degrees as shown in the cross-section in Figure 6A. Of course, there are other distributions, and the angles can be freely combined. Less than 180 degrees. The rope position of the single-degree-of-freedom joint can be bisected by 180 degrees as shown in the cross-section in Figure 7A, and it is set on the concave side of the joint, as shown in the side view in Figure 7C, otherwise the joint cannot be effectively controlled. Wherein each side rope installation quantity can be more than one. The joint combination in the mechanical arm in the present invention can be formed by a combination of multiple single-degree-of-freedom joints, or a combination of multiple two-degree-of-freedom joints, or a mixed combination of single-degree-of-freedom and two-degree-of-freedom joints , these can be set according to the actual situation.

The mechanical arm of the present invention is mainly composed of an air pressure control system and an attitude control system. As shown in Figures 9 and 10, the air pressure control system includes a closed air bag 30, an air pump 21 for inflating the air bag 30, an air pressure sensor 23 for detecting air pressure, and an air pressure controller 60 for receiving air pressure instructions After the air pressure controller 60 receives the air pressure instruction and the pressure signal sent by the air pressure sensor 23, the air pressure in the air bag is controlled by the air pump 21 or the air valve 22 to make the air pressure consistent with the air pressure instruction. The air bag 30 includes a plurality of interconnected joint; the attitude control system includes at least two servo motors 10, at least two ropes 40, and an attitude controller 70, each joint has at least two ropes to control, and the length control of each joint's ropes is coupled to each other; each The servo motor 10 controls each rope 40 independently, and the attitude controller 70 controls each servo motor 10 to adjust the length of the rope 40 it controls, so that the attitude of the joint controlled by at least two ropes 40 is consistent with the attitude command .

As shown in Figure 11, the manipulation process of the robotic arm includes the following steps:

S101: Send an air pressure command to the air pressure controller, and the air pressure sensor 23 detects the air pressure and sends out a pressure signal;

S102: After the air pressure controller receives the air pressure command and pressure signal, the air pump 21 inflates the air bag 30, and the air pressure in the air bag is controlled by the air pump 21 or the air valve 22 on the air bag 30 so that the air pressure is consistent with the air pressure command ;Adjustment of the air pressure can change the rigidity of the entire mechanical arm, thereby changing the compliance of the mechanical arm. The air pressure control system can be activated all the time when the mechanical arm is in use, or it can be activated before the mechanical arm is used. Use robotic arms to save power;

S103: After adjusting the air pressure in the airbag 30, issue an attitude command;

S104: The attitude controller 70 receives the attitude instruction, controls each servo motor 10 to adjust the length of each rope according to the attitude instruction, so that the attitude of the joint controlled by the rope is consistent with the attitude instruction.

The length control of the rope 40 of each joint is coupled. When a joint needs to change its posture, each rope on its joint needs to make a corresponding change. For example, two ropes in a single-degree-of-freedom joint, If one of the ropes executes a loosening command, the other rope executes a tightening command to ensure the smooth movement of the joints here. If the other joints do not need to change their posture, the length of the rope remains unchanged.

The mechanical arm of the present invention can be applied to a robot, which can make the robot move freely and have high safety.

The airbag of the present invention may comprise at least two joints connected together. The connection mode of the joints is tree connection mode, ring shape connection mode, or series connection mode, and several examples are described below:

Example 1

As shown in Figure 3, multiple joints of the robotic arm in this embodiment are combined into a tree-like connection mode, and the robotic arm includes the root DB of the robotic arm, the first joint GJ1, the second joint GJ2, the third joint GJ3, the The air pump 21, air valve 22, air pressure sensor 23, air pressure controller 60, closed air bag 30, a plurality of servo motors 10 and a plurality of ropes 40 not shown in four joints GJ4 and Fig. 3, the joint in the present embodiment not only There are only four joints, and there can be more joints. The root DB of the robotic arm, the first joint GJ1, the second joint GJ2, the third joint GJ3 and the fourth joint GJ4 are connected in sequence, and each joint is connected by at least two ropes. control, wherein one end of each rope 40 is connected to the end 401 of one of the joints, the other end is connected to one of the servo motors 10, and all ropes are arranged inside or in the center of the airbag 30, the mechanical arm of the present invention also includes a A plurality of sleeves 50 nesting the rope 40, wherein only one rope 40 is nested in each sleeve 50, the sleeve 50 can be bent, but its cross-sectional area does not change during the working process.

In this embodiment, there may be multiple joints, not just four joints, some of the joints are arranged horizontally, and some joints are arranged vertically. For example, as shown in FIG. 3 , the first joint GJ1 and the third joint GJ3 are arranged horizontally, and the second joint GJ2 and the fourth joint GJ4 are arranged vertically.

In this embodiment, the types of all joints may be single-degree-of-freedom joints or two-degree-of-freedom joints. The specific circumstances are determined according to actual conditions, and are not specifically limited in this embodiment. The mechanical arm in this embodiment is mainly composed of an air pressure control system and an attitude control system. The air pressure control system can be activated all the time when the robotic arm is in use, or it can be activated before the robotic arm is used to ensure that the air pressure is correct and then shut down, and then the robotic arm is used to save power. The air pressure controller 60 receives the air pressure command and the pressure signal detected by the air pressure sensor 23, and then controls the air pump 21 and the air valve 22 to control the air pressure in the airbag 30 to make it consistent with the air pressure command. Adjusting the air pressure can change the stiffness of the entire robotic arm, thereby changing the compliance of the robotic arm.

The attitude controller 70 adjusts the length of the rope 40 on the joint by controlling the servo motor 10 so as to match the attitude of the mechanical arm with the instruction. The length control of the ropes of each joint is coupled. When a joint needs to change its posture, each rope on its joint needs to make corresponding changes. If other joints do not need to change posture, the length of the rope remains unchanged.

Example 2

As shown in Figure 4, multiple joints of the robotic arm in this embodiment are combined into a ring-shaped connection, and the robotic arm includes a root DB of the robotic arm, a first joint GJ1, a second joint GJ2, a third joint GJ3, and a second joint GJ3. The four joints GJ4, the fifth joint GJ5, the sixth joint GJ6, and the air pump 21, air valve 22, air pressure sensor 23, air pressure controller 60, closed air bag 30, multiple servo motors 10, and multiple air pressure sensors that are not shown in Fig. 4 Rope 40, the joints in this embodiment are not only six, but more joints, wherein the first joint GJ1, the second joint GJ2, the third joint GJ3, the fourth joint GJ4, the fifth joint GJ5 and the sixth joint The joints GJ6 together form a ring-shaped joint combination. It can also be a joint combination that uses three or more joints to form a ring-shaped joint combination, or it can be combined into multiple ring-shaped joint combinations connected together, depending on the actual situation. depends. Likewise, in this embodiment, the types of all joints may be single-degree-of-freedom joints or two-degree-of-freedom joints. The specific situation depends on the actual situation, and is not specifically limited in this embodiment. Other technical solutions in this embodiment are the same as those in Embodiment 1, and will not be repeated here.

Example 3

As shown in Figure 5, the multiple joints of the robotic arm in this embodiment are combined into a series connection, and the robotic arm includes the root DB of the robotic arm, the first joint GJ1, the second joint GJ2, and the third joint GJ3 connected in sequence. , the joints in this embodiment are not only three, but more, and all the joints are either arranged horizontally or vertically. Other technical solutions in this embodiment are the same as those in Embodiment 1, and will not be repeated here.

To sum up, the mechanical arm provided by the present invention uses a closed airbag as a support, which reduces the harm caused by the collision of the mechanical arm with other contact objects during work and transportation, and also uses multi-segment joints with multiple degrees of freedom. The combination controls the movement of the robotic arm and the rope is hidden in the airbag, making the robotic arm more flexible and more beautified. The mechanical arm of the present invention can also be applied to sports robots or stand-in robots.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (11)

1. a mechanical arm, it is characterized in that, described mechanical arm comprises at least one servomotor, enclosed air bag, at least one rope, described air bag comprises at least one joint, the cross-sectional area of described joint position is less than the cross-sectional area of other position of described air bag, one end of each rope connects the wherein end in a joint, and the other end is connected with a servomotor wherein, controls the attitude in described joint by the length of described servomotor adjusting rope.

2. mechanical arm according to claim 1, it is characterized in that, described mechanical arm comprises at least two ropes, one end of each rope connects the wherein end in a joint, the other end is connected with a servomotor wherein, and each joint is controlled by least two ropes, the length of each each rope of joint is controlled and is intercoupled, to control the attitude in described joint.

3. mechanical arm according to claim 2, is characterized in that, described mechanical arm comprises that at least two servomotors, each servomotor control a rope independently.

4. mechanical arm according to claim 1 and 2, it is characterized in that, described mechanical arm also comprises the sleeve pipe for nested described rope, described sleeve pipe is all arranged on the inside of described air bag, described in each, the entrance of sleeve pipe is fixed therein the top in a joint, and its outlet is fixed on the root of described mechanical arm.

5. mechanical arm according to claim 1 and 2, is characterized in that, described air bag comprises at least two joints that link together, and the connected mode in joint is tree-shaped connected mode or is connected in series mode.

6. mechanical arm according to claim 2, is characterized in that, described joint comprises single-DOF-joint, and described single-DOF-joint is controlled by two ropes, and two rope positions are divided equally with 180 degree in the cross section in described joint.

7. mechanical arm according to claim 2, it is characterized in that, described joint comprises two-freedom degree joint, described two-freedom degree joint is controlled by least three ropes, and the position of each rope in described two-freedom degree joint is divided to be less than the angle combination of 180 degree in the cross section in described joint.

8. mechanical arm according to claim 7, is characterized in that, the position of each rope in described two-freedom degree joint number with described rope in the cross section in described joint is divided equally.

9. mechanical arm according to claim 1 and 2, it is characterized in that, described mechanical arm comprises for the air pump to described airbag aeration, for detection of the baroceptor of air pressure and for receiving the gas pressure regulator of air pressure instruction, described gas pressure regulator receive air pressure instruction and the pressure signal that sent by baroceptor after, by described air pump, the air pressure in described air bag is controlled and is made its air pressure consistent with air pressure instruction; Described mechanical arm also comprises attitude controller, controls the attitude in described joint for controlling the length of described servomotor adjusting rope.

10. a control method for mechanical arm, is characterized in that, comprises the following steps:

Gas pressure regulator is sent to air pressure instruction, and detect air pressure and send pressure signal by baroceptor;

Gas pressure regulator receives after described air pressure instruction and pressure signal, and by air pump, to airbag aeration, and the air valve on air pump or described air bag controls the air pressure in air bag, makes its air pressure consistent with described air pressure instruction;

Adjust after the air pressure in air bag, send attitude command;

Attitude controller receives attitude command, controls each servomotor and according to described attitude command, adjusts the length of each rope, makes the attitude in the joint controlled by rope consistent with described attitude command.

11.Yi Zhong robot, is characterized in that, comprises mechanical arm as claimed in any one of claims 1-9 wherein.