Flexible capturing robot based on rope driving

Abstract

The invention discloses a flexible capturing robot based on rope driving, which comprises a base, first joints are mounted at the triangular positions of the base, first rods are mounted on the first joints, second joints are mounted at the ends, away from the first joints, of the first rods, second rods are mounted on the second joints, and the second rods are mounted on the second joints. One end of the second rod extends to one side of the first joint and is provided with a third joint, and the third joint is provided with a third rod. The mechanical arm structure is formed by connecting the first rod, the second rod, the third rod and the connecting joint which can rotate, the occupied space is small in the folded state, the capturing space is large in the unfolded and enveloped state, and the capturing effect is good. The folding states of the three mechanical arms are completely consistent, the three mechanical arms are distributed on the base in an equilateral triangle structure, the three ropes are folded together on the base and driven by the same motor, and therefore controllability and sensitivity are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of space capture, and in particular relates to a dexterous capture robot driven by a rope. Background Art

[0002] In recent years, due to the increasing frequency of human space activities, the amount of space debris has increased rapidly, posing a serious threat to space activities, spacecraft and astronauts. In order to cope with the increasingly serious problem of space debris, we should take active measures to reduce the generation of space debris and actively explore new technologies and methods to clean up space debris to ensure the sustainability of the space environment.

[0003] At present, common space debris cleaning technologies include laser irradiation technology, push-off technology, adsorption technology and mechanical capture technology. Among them, mechanical capture technology is divided into rigid capture (robotic arm grasping) and flexible capture (such as flying net capture). Rigid capture technology has been deeply studied, is flexible and convenient, and has strong control capabilities, but the robotic arm control accuracy is high, the interaction is complex, and it is prone to collision; while the flexible capture system is light in weight, does not require precise capture position, has large error redundancy, and can capture rotating targets, but most of them are difficult to capture repeatedly, difficult to control, and have low reliability. Therefore, it is of great significance to study a capture method that can combine the advantages of rigid capture and flexible capture.

[0004] The space flexible rope net has good capture capability and can capture multiple rotating space debris and achieve stable wrapping and winding. The rope-driven flexible robotic arm can be deployed to capture large space debris within the small space limit of the carrier. However, since most of the large space debris is in a high-speed rotating state, the capture process is easy to damage the robotic arm structure, and the current flexible robotic arm mechanism is relatively complex to deploy and is too heavy. The development of a dexterous capture robot that combines a space rope net with a rope-driven deployable flexible robotic arm can better solve these problems. Summary of the invention

[0005] The object of the present invention is to provide a rope-driven dexterous capture robot to solve the above-mentioned problems.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a dexterous capture robot based on rope drive, comprising a base, wherein a No. 1 joint is installed at each triangular part of the base, a No. 1 rod is installed on the No. 1 joint, a No. 2 joint is installed at one end of the No. 1 rod away from the No. 1 joint, a No. 2 rod is installed on the No. 2 joint, one end of the No. 2 rod extends to one side of the No. 1 joint and is installed with a No. 3 joint, a No. 3 rod is installed on the No. 3 joint, and the No. 1 rod, the No. 2 rod and the No. 3 rod are connected by the No. 1 joint, the No. 2 joint and the No. 3 joint. The turning connection shape of the No. 1 joint and the No. 3 joint is arranged in a Z shape, a motor is installed in the middle of the base and the output shaft of the motor is connected to the rope collecting disk, three ropes are wound around the rope collecting disk, and each rope passes through the No. 1 rod, the No. 2 joint, the No. 2 rod, the No. 3 joint and the No. 3 rod at an angle on the base in sequence and finally comes out, a net is fixed on the outer edges of the three No. 1 rods, the No. 2 rods and the No. 3 rods on the triangle on the base, and the net is followed by the No. 1 rod, the No. 2 rod and the No. 3 rods to open and capture them under the pulling of the ropes.

[0007] Preferably, the joint No. 1 specifically includes two mutually meshing connectors 1 and 2, and connector 1 is installed on the base, connector 2 is connected to joint No. 1, both sides of connector 1 and connector 2 are provided with mounting holes and compression springs are arranged inside the mounting holes, and both sides of connector 1 and connector 2 that are meshed and connected are provided with limiting cover 1, the rod No. 1 also includes two limiting rods and the limiting rods pass through the bearings and sliders installed on the limiting cover 1 and pass through connector 2 or connector 1 and extend from a limiting cover on the other side.

[0008] Preferably, the specific structure of joint No. 2 is supplemented with joint No. 3 compared with joint No. 1. Joint No. 3 is arranged on the inner side of limit cover No. 2 which corresponds to joint No. 1, and a hole is opened inside joint No. 3 to place an iron rod to enhance the structural strength. Joint No. 3 is coaxial with limit cover No. 2, and together with the two places, they form a mechanism for fixing the tension spring.

[0009] Preferably, the specific structure of the No. 3 joint is compared with the structure of the No. 1 joint in that the limiting angle on the No. 3 joint is greater than the limiting angle on the No. 1 joint.

[0010] The technical effects and advantages of the present invention are as follows: the mechanical arm structure of the present invention is composed of three rotatable rods, rods 1, 2 and 3, connected by connecting joints. The occupied space in the folded state is small, and the capture space in the unfolded and enveloped states is large. The folded states of the three mechanical arms are completely consistent and distributed in an equilateral triangle structure on the base. The three ropes are gathered together on the base and driven by the same motor, thereby improving controllability and sensitivity.

[0011] 2. The use of rope drive can keep the driver with larger mass (which can be a motor) away from the end actuator. The flexible robot arm driven by the rope has the characteristics of light mass and large deformation, and can realize bending, winding and other movements to complete the task of capturing space debris;

[0012] 3. Adopt a foldable / expandable structure to solve the problem that the flexible robotic arm cannot capture large space debris due to space limitations of the launch vehicle;

[0013] 4. The structure combining the rope net and the mechanical arm can increase the capture range, eliminate the need to accurately aim at the capture position, and increase the error redundancy. At the same time, it increases the control ability to achieve efficient, accurate and safe capture of small to large space debris;

[0014] 5. Adding a brush structure can slow down the rotation speed of space debris, reduce resistance during the capture process, and reduce the risk of robot structure being destroyed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the folded state structure of the space debris capture robot in an embodiment of the present invention;

[0016] Figure 2 It is a schematic diagram of the structure of the space debris capture robot in the folded state according to an embodiment of the present invention;

[0017] Figure 3 It is a schematic diagram of the structure of the space debris capture robot in the unfolded state according to an embodiment of the present invention;

[0018] Figure 4 This is a schematic diagram of the joint structure between the No. 1 rod and the base of the space debris capture robot in an embodiment of the present invention;

[0019] Figure 5 This is a schematic diagram of the structure of the second joint of the space debris capture robot in an embodiment of the present invention;

[0020] Figure 6 This is a schematic diagram of the structure of the third joint of the space debris capture robot in an embodiment of the present invention;

[0021] Figure 7 This is a schematic diagram of the structure of a limit cover in the first joint of the space debris capture robot in an embodiment of the present invention;

[0022] Figure 8 It is a schematic diagram of the structure of the second joint of the space debris capture robot in an embodiment of the present invention;

[0023] Fig. 9 Schematic diagram of the limit cover structure in the No. 3 joint of the space debris capture robot in an embodiment of the present invention.

[0024] Fig.10 This is a schematic diagram of the unfolding motion structure of the limit cover and the hook in the second joint of the space debris capture robot in an embodiment of the present invention.

[0025] Fig.11 It is a schematic diagram of the envelope motion structure of the limit cover and the hook in the second joint of the space debris capture robot in an embodiment of the present invention.

[0026] Fig.12 Schematic diagram of the rope installation structure in an embodiment of the present invention.

[0027] In the figure: 1. base; 2. rope collecting disc; 3. pole No. 1; 4. pole No. 2; 5. pole No. 3; 6. joint No. 1; 7. joint No. 2; 8. joint No. 3; 9. net; 10. connector No. 1; 11. connector No. 2; 12. compression spring; 13. slider; 14. limit cover No. 1; 15. bearing; 16. limit pole; 17. tension spring; 18. hook; 19. limit cover No. 2; 20. limit cover No. 3; 21. connecting hole; 22. arc groove No. 1; 23. arc groove No. 2; 24. arc groove No. 3; 25. slider groove; 26. compression spring hole; 27. iron rod; 28. hook column DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The present invention provides a dexterous capture robot based on rope drive as shown in the figure, comprising a base 1, a first joint 6 is installed at each triangular part of the base 1, a first rod 3 is installed on the first joint 6, a second joint 7 is installed at one end of the first rod 3 away from the first joint 6, a second rod 4 is installed on the second joint 7, one end of the second rod 4 extends to one side of the first joint 6 and is installed with a third joint 8, a third rod 5 is installed on the third joint 8, and the first rod 3, the second rod 4 and the third rod 5 are connected by the first joint 6, the second joint 7 and the third joint 7. The turning connection shape of the joint 8 is set in a Z shape, a motor is installed in the middle of the base 1 and the output shaft of the motor is connected to the rope collecting disk 2, three ropes are wound around the rope collecting disk 2, and each rope passes through the No. 1 rod 3, the No. 2 joint 7, the No. 2 rod 4, the No. 3 joint 8 and the No. 3 rod 5 on a corner of the base 1 in sequence and finally passes out. A net 9 is fixed on the outer edges of the three No. 1 rods 3, No. 2 rods 4 and No. 3 rods 5 on the triangle on the base 1, and follows the No. 1 rod 3, No. 2 rod 4 and No. 3 rod 5 to open and capture under the pulling of the ropes.

[0030] Specifically, joint No. 1 6 specifically includes two mutually meshing connectors 10 and 11, and connector 10 is installed on the base 1, connector 2 11 is connected to joint No. 1 6, both sides of connector 10 and connector 2 11 are provided with mounting holes, and compression springs 12 are arranged inside the mounting holes, and limiting covers 14 are arranged on both sides of the meshing connection between connector 10 and connector 2 11, and rod No. 1 3 also includes two limiting rods 16, and the limiting rods 16 pass through the bearings 15 and the slider 13 installed on the limiting cover 14 and pass through connector 2 11 or connector 10 to extend from the limiting cover 14 on the other side.

[0031] Specifically, the specific structure of joint No. 2 7 is supplemented with joint No. 3 8 compared with joint No. 1 6. Joint No. 3 8 is arranged on the inner side of limit cover No. 2 7 which corresponds to joint No. 1 6, and a hole is opened inside joint No. 3 8 for placing iron rod 27 to enhance structural strength. Joint No. 3 8 is coaxial with limit cover No. 2 19, and together with the two places form a mechanism for fixing the tension spring 17.

[0032] Specifically, the specific structure of joint No. 3 8 is different from that of joint No. 1 6 in that the limiting angle on joint No. 3 8 is greater than the limiting angle on joint No. 1 6 .

[0033] Working principle: The present invention is specifically composed of three mechanical arms symmetrically distributed on the base, each of which is composed of a first rod 3, a second rod 4 and a third rod 5, and is respectively connected to each other by a first joint 6, a second joint 7 and a third joint 8 in the middle. The first rod 3, the second rod 4 and the third rod 5 are all hollow structures and can be used to place ropes. The ropes run through the entire mechanical arm from the top of the mechanical arm. Fig.12 As shown, the rope collecting disk gathered on the base is driven by the motor to rotate, thereby generating tension on the rope. Due to the eccentricity between the rope and the center of the joint, the tension of the rope on the joint generates a rotational torque, which causes relative rotation between the two adjacent rods, thereby achieving the task of folding, unfolding and then enveloping. The three robotic arms are connected by a flexible net, which follows the movement of the robotic arms. A brush structure is arranged on the flexible net to reduce the rotation speed of the rotating object and prevent the robotic arms from being collided.

[0034] like Figure 1 , 2 and Figure 3 The calculation formulas for the total space size in the three states shown are:

[0035] When folded:

[0036] After expansion:

[0037] When enveloping:

[0038] Among them, is the base area; L is the length of a single rod of the robotic arm; is the angle between rod 1 and the base in the folded state; is the angle between rod 1 and the base in the unfolded state; is the radius of the circumscribed circle formed by the base; is the radius of the circumscribed circle formed by the tops of the three robotic arms in the unfolded state;

[0039] The space debris capture robot arm is in the folded state. All ropes gather at the rope collection disc 2. The rope passes from the base 1 through the outside of the joint 2 and enters the rod 3. It passes through the rod and goes around the outside of the joint 7 and enters the rod 4. It passes through the rod and goes around the outside of the joint 8 and enters the rod 5. Finally, it passes out of the rod. The motor installed on the chassis 1 drives the rope collection disc 2 to rotate, so that tension is generated on the rope, which drives the gear parts on the connectors 10 and 11 on the joints 6, 7, and 8 to rotate, and then the rods connected to the connectors start to rotate. When the rope is pulled, the rods start to unfold from the "Z" shape. In the folded state shown in the figure, the rod 3 is 45 degrees to the base, and the angle between the two adjacent rods is 0 degrees. The three robot arms are folded and gathered together to form a regular triangular pyramid structure with the base 1.

[0040] like Figure 2 As shown, the space debris capture robot arm is in the expanded state. When the robot is in the expanded state, the No. 1 rod 3 and the base 1 form an angle of 120 degrees, the No. 1 rod 3 and the No. 2 rod 4 form an angle of 180 degrees, the No. 2 rod 4 and the No. 3 rod 5 form an angle of 150 degrees, and the net 9 is placed on the inner side of the robot arm.

[0041] like Figure 3 As shown, the space debris capture arm is in the envelope state. When the arm is fully enveloped, the No. 1 rod 3 and the No. 2 rod 4 form an angle of 120 degrees, and the No. 2 rod 4 and the No. 3 rod 5 form an angle of 150 degrees.

[0042] like Figure 4 As shown, the outer sides of the connector 10 and the connector 11 are designed with four symmetrical compression spring holes 26. The compression spring 12 is inserted into the hole from the radial direction, with the lower end against the bottom end of the compression spring hole, and the upper end is limited by the limit rod 16 from the radial outer end to press the compression spring 12. The symmetrical compression springs 12 on both sides ensure that the movement of the limit rod 16 on both sides is symmetrical and stable. The limit rod 16 passes through the No. 1 arc groove 22 on the limit cover 14, the upper end of the compression spring 12 (the compression spring 12 is in a compressed state at this time), and the slider 11 (the slider 11 is located in the slider groove 25 inside the gear, which is used to glue the limit rod to prevent it from falling off), and passes through the limit cover symmetrical to it on the other side; the surface pattern of the limit cover 14 is as shown Figure 7As shown, the two connecting holes 21 on the limit cover 14 are used to fix with the gears on the connector 10 and the connector 11; the connector 10 is fixed on the base, and the rope passes through the connecting hole 21 on the connector 10, bypasses the two meshing gears, and then passes through the small hole on the connector 11 into the No. 2 rod, and the pulling force of the rope drives the gears on the connector 11 and the connector 10 to rotate relative to each other; at this time, the connector 11 and the limit rod 16 on the connector 10 are also relatively rotated, and slide relatively in the No. 1 arc groove 22 of the limit cover 14, until the part of the track protrudes radially outward, the compression springs 12 at both ends release the elastic force to push the limit rod 16 to the protrusion of the track, and at this time, continuing to pull the rope cannot make the joint continue to rotate, thereby realizing the limiting function; the limiting angle of the No. 1 arc groove 22 of the limit cover 14 is (120-45) / 2=37.5 degrees, and the total limiting angle of the relative movement of the connector 10 and the connector 11 is 37.5*2=70 degrees.

[0043] like Figure 5 As shown, compared with joint 1 6, joint 7 No. 2 is additionally provided with hook 18, and limit cover 1 No. 2 is additionally provided with hook column 27 compared with limit cover 1 14, and holes are punched at both ends of hook 18 for placing iron rod 27 to enhance structural strength, and the circular hole of hook 18 is coaxial with the connecting hole 21 on limit cover 1 No. 2, and is located between limit cover 1 No. 2 and connector 10, and together constitutes a mechanism for fixing tension spring 17 as shown in FIG. Fig.11 The angle between the first and second rods needs to be limited twice, and the surface pattern of the limit cover 19 is as shown Figure 8 As shown, when the rope is pulled, the limit rod 16 is as shown in Fig.10 The movement direction is shown, and the limit angle when unfolded is 180-0=180 degrees. After unfolding, the second arc groove 23 is as shown in FIG. Fig.11 The movement in the direction shown ensures that the joint cannot return to the folded state after being unfolded. Then the pulling rope will cause the joint to continue to rotate in the same direction. The movement of the limiting rod 16 will push the hook 18 and drive it to rotate together. At this time, the tension spring 17 is stretched to the end of the second arc groove 23 of the limiting cover 19. This is the limit angle when enveloping. The first rod 3 and the second rod 4 are 120 degrees, and the limiting angle of the second arc groove 23 of the limiting cover 19 is (180-120) / 2=30 degrees. If the enveloping state is to be transitioned to the unfolding state, the pulling rope can be changed to releasing the rope, and the tension spring 17 plays a role, releasing the elastic force, so that the connector 11 is driven to rotate in the opposite direction.

[0044] like Figure 6 As shown, the principle of the third joint 8 is the same as that of the first joint 6, only the limit angle is changed, and the angle between the second rod and the third rod needs to be limited once. The surface pattern of the limit cover 3 20 is as shown in Fig. 9 As shown, the limiting angle is 150-0=150 degrees. The limiting angle of the third arc groove 24 of the limiting cover 20 is (150-0) / 2=75 degrees, and the total limiting angle of the relative movement of the connector 11 is 75*2=150 degrees.

[0045] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A rope-driven dexterous capture robot, characterized in that: The invention comprises a base (1), wherein a first joint (6) is installed at each triangular part of the base (1), a first rod (3) is installed on the first joint (6), a second joint (7) is installed on one end of the first rod (3) away from the first joint (6), a second rod (4) is installed on the second joint (7), one end of the second rod (4) extends to one side of the first joint (6) and is installed with a third joint (8), a third rod (5) is installed on the third joint (8), and the first rod (3), the second rod (4) and the third rod (5) are connected by the turning points of the first joint (6), the second joint (7) and the third joint (8). The connection is arranged in a Z-shape, a motor is installed in the middle of the base (1), and the output shaft of the motor is connected to a rope collecting disk (2) in a transmission manner, three ropes are wound and connected to the rope collecting disk (2), and each rope passes through a No. 1 rod (3), a No. 2 joint (7), a No. 2 rod (4), a No. 3 joint (8) and a No. 3 rod (5) on a corner of the base (1) in sequence and finally passes out, and a net (9) is fixedly sleeved on the outer edges of the three No. 1 rods (3), No. 2 rods (4) and No. 3 rods (5) on the triangle of the base (1), and follows the No. 1 rod (3), No. 2 rods (4) and No. 3 rods (5) to be pulled by the ropes to realize opening and capturing.

2. The rope-driven dexterous capture robot according to claim 1, characterized in that: The joint No. 1 (6) specifically comprises two mutually meshing connectors 1 (10) and 2 (11), and the connector 1 (10) is mounted on the base (1), and the connector 2 (11) is connected to the joint No. 1 (6). Both sides of the connector 1 (10) and the connector 2 (11) are provided with mounting holes, and compression springs (12) are arranged inside the mounting holes. Limiting covers 1 (14) are arranged on both sides of the meshing connection between the connector 1 (10) and the connector 2 (11), and the rod No. 1 (3) further comprises two limiting rods (16), and the limiting rods (16) penetrate the bearings (15) and the slider (13) mounted on the limiting cover 1 (14), penetrate the connector 2 (11) or the connector 1 (10), and extend from the limiting cover 1 (14) on the other side.

3. The rope-driven dexterous capture robot according to claim 1, characterized in that: The specific structure of the No. 2 joint (7) is that a No. 3 joint (8) is added to the No. 1 joint (6). The No. 3 joint (8) is arranged on the inner side of the No. 2 joint (7) and the limit cover No. 1 (6), and a hole is opened inside the No. 3 joint (8) for placing an iron rod to enhance the structural strength. The No. 3 joint (8) is coaxial with the limit cover No. 2 (19), and together with the two places, they form a mechanism for fixing the tension spring (17).

4. The rope-driven dexterous capture robot according to claim 1, characterized in that: Compared with the structure of the No. 1 joint (6), the specific structure of the No. 3 joint (8) is that the limiting angle on the No. 3 joint (8) is greater than the limiting angle of the No. 1 joint (6).

Images