A collaborative robot arm and method of controlling the same

Abstract

The application relates to the technical field of robots, and provides a cooperative work mechanical arm and a control method thereof. The application comprises a first mechanical arm, a second mechanical arm, a third mechanical arm and a fourth mechanical arm, the first mechanical arm, the second mechanical arm and the third mechanical arm are located on a first track, the fourth mechanical arm is located on a second track, the first track and the second track are arranged in parallel, and the first track and the second track are straight tracks; a first safety distance is kept between the second mechanical arm and the first mechanical arm, a second safety distance is kept between the third mechanical arm and the first mechanical arm, and the second safety distance is greater than or equal to the first safety distance. The beneficial effect is that the multiple mechanical arms have different safety distances with the first mechanical arm, the interference between the mechanical arms during work is avoided, the work can be cooperatively completed, and the maximum cooperative work space is obtained.

Description

Technical Field

[0001] This invention relates to the field of robotics, specifically to a collaborative robotic arm and its control method. Background Technology

[0002] With the rapid development of industrial intelligence, advanced robots are gradually being introduced into traditional manufacturing industries to replace manual labor. Due to technological development and work requirements, multiple mobile robots work together in the same work area at the same time. How to ensure the safety of these mobile robots when working together is an issue that needs to be addressed.

[0003] Therefore, this invention is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a collaborative robotic arm and its control method to solve the technical problems existing in the prior art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a collaborative robotic arm, comprising: a first robotic arm, a second robotic arm, a third robotic arm, and a fourth robotic arm, wherein the first robotic arm, the second robotic arm, and the third robotic arm are located on a first track, and the fourth robotic arm is located on a second track, wherein the first track and the second track are arranged in parallel, and both the first track and the second track are straight tracks;

[0006] Among them, the first robotic arm is the main moving arm, the second robotic arm and the third robotic arm are the following arms, and the fourth robotic arm is the cooperating arm;

[0007] The second robotic arm and the third robotic arm move closer to the first robotic arm with the first robotic arm as a reference; the second robotic arm maintains a first safe distance from the first robotic arm, and the third robotic arm maintains a second safe distance from the first robotic arm, wherein the second safe distance is greater than or equal to the first safe distance;

[0008] When the first safety distance is equal to the second safety distance, the second robotic arm and the third robotic arm approach the first robotic arm at the same speed; when the first safety distance is less than the second safety distance, the speed at which the second robotic arm approaches the first robotic arm is greater than the speed at which the third robotic arm approaches the first robotic arm.

[0009] Before starting the operation, the first robotic arm moves to a designated position on the first track, the second robotic arm moves to maintain the first safe distance from the first robotic arm, and the third robotic arm moves to maintain the second safe distance from the first robotic arm; the fourth robotic arm determines its position on the second guide rail based on the positions of the first robotic arm, the second robotic arm, and the third robotic arm.

[0010] In an optional embodiment, the first, second, third, and fourth robotic arms are all multi-degree-of-freedom serial robotic arms with identical structures. The ends of the first, second, third, and fourth robotic arms are all equipped with rope-driven end effectors; the execution end of the end effector is a suction cup.

[0011] In an optional embodiment, the first robotic arm, the second robotic arm, the third robotic arm, and the fourth robotic arm each include at least two articulated motion arms.

[0012] When the second robotic arm maintains a first safe distance from the first robotic arm and the third robotic arm maintains a second safe distance from the first robotic arm, the first moving arms of the first, second, and third robotic arms are parallel to each other, and the second moving arms of the first, second, and third robotic arms are parallel to each other.

[0013] In an optional embodiment, before the operation begins, before the first robotic arm, the second robotic arm, and the third robotic arm move along the first guide rail, the first moving arm and the second moving arm of the first robotic arm, the third robotic arm, and the third robotic arm are first adjusted to be parallel to each other.

[0014] In an optional embodiment, at least two sets of reference points are provided on both the first and second moving arms of the first robotic arm, with each set of two reference points respectively located at both ends of the first and second moving arms.

[0015] The first and second moving arms of the second and third robotic arms are each provided with at least two sets of reference points, and the two reference points in each set are respectively located at the two ends of the first and second moving arms.

[0016] At least two sets of reference points on the first and second moving arms of the second and third robotic arms are respectively set to correspond to at least two sets of reference points on the first and second moving arms of the first robotic arm.

[0017] On the other hand, the present invention also provides a control method using the cooperative robotic arm described above, comprising:

[0018] S1: Before operation, determine the position of the first robotic arm on the first track, and determine the positions of the second and third robotic arms according to the first safety distance and the second safety distance;

[0019] S2: Start the operation. The first robotic arm starts to move and controls its end effector to the designated suction point a1. Then the second robotic arm moves and controls its end effector to the designated suction point a2. The third robotic arm moves and controls its end effector to the designated suction point a3.

[0020] S3: The first robotic arm, the second robotic arm, and the third robotic arm work together to keep the relative positions of the adsorption points a1, a2, and a3 unchanged.

[0021] In an optional embodiment, the adsorption points a1, a2, and a3 are respectively the contact center points between the adsorbed object and the suction cups on the rope-driven end effectors at the ends of the robotic arms. The center of gravity of the adsorbed object can be adjusted by adjusting the bending angle of each rope-driven end effector.

[0022] In an optional embodiment, after adjusting the bending angle of each of the rope-driven end effectors to adjust the center of gravity of the adsorbed object, if the first, second, and third robotic arms cannot meet the load requirements, the fourth robotic arm is activated to readjust the center of gravity of the adsorbed object to complete the operation.

[0023] The beneficial effects of this invention are as follows:

[0024] (1) The present invention sets four robotic arms on two guide rails, and each robotic arm has a rope-driven flexible end effector at the end, which can flexibly achieve the adsorption of the object being grasped. In particular, the bending degree of each end effector can be adjusted to change the center of gravity of the object being grasped and adsorbed, making the grasping and adsorption more stable.

[0025] (2) By setting multiple robotic arms with different safety distances from the first robotic arm, the present invention ensures that the robotic arms do not interfere with each other during operation, and can cooperate to complete the operation, and obtain the maximum collaborative work space. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1This is a schematic diagram of the overall structure of a collaborative robotic arm provided in an embodiment of the present invention.

[0028] Figure 2 for Figure 1 A magnified schematic diagram of the local structure at point A in the middle.

[0029] The attached figures are labeled as follows:

[0030] 1-First robotic arm, 2-First robotic arm, 3-Third robotic arm, 4-Fourth robotic arm; 11-First motion arm, 12-Second motion arm, 13-End effector, 131-Rope-driven multi-degree-of-freedom arm segment, 132-Suction cup. Detailed Implementation

[0031] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0032] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly or indirectly located on that other component. When a component is referred to as "connected to" another component, it can be directly or indirectly connected to that other component. The terms "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate orientations or positions based on the accompanying drawings, and are for ease of description only, and should not be construed as limiting the technical solution. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. "Multiple" means two or more, and "several" means any number including one, unless otherwise explicitly specified.

[0033] Please see the appendix Figure 1-2 The purpose of this embodiment is to provide a collaborative robotic arm, including: a first robotic arm 1, a second robotic arm 2, a third robotic arm 3 and a fourth robotic arm 4. The first robotic arm 1, the second robotic arm 2 and the third robotic arm 3 are located on a first track, and the fourth robotic arm 4 is located on a second track. The first track and the second track are arranged in parallel, and both the first track and the second track are straight tracks.

[0034] Among them, the first robotic arm 1 is the main moving arm, the second robotic arm 2 and the third robotic arm 3 are the following arms, and the fourth robotic arm 4 is the cooperating arm.

[0035] The second robotic arm 2 and the third robotic arm 3 approach the first robotic arm 1 with the first robotic arm 1 as a reference; the second robotic arm 2 maintains a first safe distance from the first robotic arm 1, and the third robotic arm 3 maintains a second safe distance from the first robotic arm 1, wherein the second safe distance is greater than or equal to the first safe distance;

[0036] When the first safety distance is equal to the second safety distance (the second and third robotic arms are located on both sides of the first robotic arm 1), the second robotic arm 2 and the third robotic arm 3 approach the first robotic arm 1 at the same speed; when the first safety distance is less than the second safety distance, the speed at which the second robotic arm 2 approaches the first robotic arm 1 is greater than the speed at which the third robotic arm 3 approaches the first robotic arm 1. In this case, the second and third robotic arms are located on the same side of the first robotic arm 1. When the third robotic arm 3 moves, the second robotic arm 2 has already moved to the first safety distance or is in the process of moving. For safety reasons, the moving speed of the third robotic arm 3 must be less than the moving speed of the second robotic arm 2. The second robotic arm 2 has completed its movement to maintain a first safe distance from the first robotic arm. The movement speed of the third robotic arm 3 should be less than that of the second robotic arm 2 to reduce the losses caused by an accident, especially to reduce the possibility of impact on the first robotic arm 1 (if the speed of the third robotic arm is low, it may only impact the second robotic arm 2). If the second robotic arm 2 is in the process of moving to maintain a first safe distance from the first robotic arm, the movement speed of the third robotic arm 3 should be less than that of the second robotic arm 2 to avoid collision interference between the third robotic arm 3 and the second robotic arm 2 as much as possible (the second robotic arm moves faster), especially when there is a failure in the relative parallel adjustment of the moving arms of each robotic arm.

[0037] Before starting the operation, the first robotic arm 1 moves to a designated position on the first track, the second robotic arm 2 moves to maintain the first safe distance from the first robotic arm 1, and the third robotic arm 3 moves to maintain the second safe distance from the first robotic arm 1. The fourth robotic arm 4 determines its position on the second guide rail based on the positions of the first robotic arm 1, the second robotic arm 2, and the third robotic arm 3. The first safe distance refers to the distance at which the first robotic arm 1 and the second robotic arm do not interfere with each other during operation, and the second safe distance refers to the distance at which the third robotic arm does not interfere with the first or second robotic arms during operation. These adjustments before operation ensure that the robotic arms do not interfere with each other during operation, while still coordinating to complete the task and maximizing the collaborative workspace.

[0038] Specifically, the first robotic arm 1, the second robotic arm 2, the third robotic arm 3, and the fourth robotic arm 4 are all multi-degree-of-freedom serial robotic arms with identical structures. Each of these robotic arms has a cable-driven end effector 13 at its end; the actuating end of the end effector 13 is a suction cup 14. Each of these robotic arms includes at least two hinged motion arms. When the second robotic arm 2 maintains a first safe distance from the first robotic arm 1, and the third robotic arm 3 maintains a second safe distance from the first robotic arm 1, the first motion arms 11 of each of the first, second, and third robotic arms 11 are parallel to each other, and the second motion arms 12 of each of the first, second, and third robotic arms 11 are parallel to each other. Before starting operation, before the first, second, and third robotic arms 1 and 3 move along the first guide rail, the first and second motion arms of each of the first, second, and third robotic arms 1 and 3 are adjusted to be approximately parallel to each other. With the above settings, for example, the first moving arm 11 of the first robotic arm is approximately parallel to the first moving arms of the second robotic arm 2 and the third robotic arm 3, and the second moving arm 12 of the first robotic arm is approximately parallel to the second moving arms of the second robotic arm and the third robotic arm, respectively, the safety of the second and third robotic arms during the movement to the above two safe distances is further guaranteed.

[0039] In an optional embodiment, at least two sets of reference points are provided on the first moving arm 11 and the second moving arm 12 of the first robotic arm 1, with each set of two reference points located at both ends of the first and second moving arms, respectively. At least two sets of reference points are also provided on the first and second moving arms of the second and third robotic arms, with each set of two reference points located at both ends of the first and second moving arms, respectively. The at least two sets of reference points on the first and second moving arms of the second and third robotic arms correspond to the at least two sets of reference points on the first moving arm of the first robotic arm 1 and the second moving arm 2, respectively. By setting each set of reference points, when the distance between the second robotic arm 2 and the first robotic arm 1 is a first safe distance and the distance between the third robotic arm 3 and the first robotic arm 1 is a second safe distance, the parallelism between the robotic arms can be finally confirmed. The corresponding first and second moving arms in each robotic arm can be adjusted from a roughly parallel state to a completely parallel state, and it can also be confirmed whether the first and second safe distances are preset distances.

[0040] Example 2

[0041] On the other hand, the present invention also provides a control method using the collaborative robotic arm as described in the above embodiments, comprising:

[0042] S1: Before operation, determine the position of the first robotic arm 1 on the first track, and determine the positions of the second robotic arm 2 and the third robotic arm 3 according to the first safety distance and the second safety distance;

[0043] S2: Start the operation. The first robotic arm 1 starts to move and controls its end effector 13 to the designated suction point a1. Then the second robotic arm 2 moves and controls its end effector to the designated suction point a2. Then the third robotic arm 3 moves and controls its end effector to the designated suction point a3.

[0044] S3: The first robotic arm 1, the second robotic arm 2, and the third robotic arm 3 work together to keep the relative positions of the adsorption points a1, a2, and a3 unchanged.

[0045] In an optional embodiment, adsorption points a1, a2, and a3 are the contact center points between the adsorbed object and the suction cups on the rope-driven end effectors of each robotic arm. The center of gravity of the adsorbed object can be adjusted by adjusting the bending angle of each rope-driven end effector. Especially after the positions of the first, second, and third robotic arms are determined, the center of gravity of the adsorbed object can be finely adjusted by changing the bending angle of the rope-driven end effectors, resulting in better gripping of the adsorbed object and preventing it from falling during movement.

[0046] In an optional embodiment, after adjusting the bending angle of each of the rope-driven end effectors to adjust the center of gravity of the adsorbed object, if the first, second, and third robotic arms cannot meet the load requirements, the fourth robotic arm is activated to readjust the center of gravity of the adsorbed object to complete the task. When using four robotic arms, after the positions of the four robotic arms are determined, the bending degree of each rope-driven end effector is adjusted in a coordinated manner so that the weight of the adsorbed object is reasonably distributed to each robotic arm, ensuring safety during the handling of the adsorbed object.

[0047] In an optional embodiment, when using three or four robotic arms to adjust the center of gravity of the adsorbed object, it is necessary to adjust the bending angle of the main body of the robotic arm of the rope-driven end effector of the first, second, third and fourth robotic arms in sequence. This can ensure the position of the center of gravity adjustment and prevent the adsorbed object from falling. For example, after the bending angle of the rope-driven end effector at the end of the first and second robotic arms is determined, it can be determined whether the adsorbed object can be reliably adsorbed after the bending angle of the rope-driven end effector of the third robotic arm is adjusted.

[0048] In another embodiment, after the adsorbed object is adsorbed by the suction cup of the rope-driven end effector of the first robotic arm 1, it is determined whether the first robotic arm 1 alone can meet the load requirements. If it can, the second robotic arm 2 does not need to be activated. If it does not meet the load requirements, the second robotic arm 2 is activated, and the suction cup of the rope-driven end effector of the second robotic arm 2 is used to simultaneously adsorb the adsorbed object. If it can meet the load requirements, the third robotic arm 3 does not need to be activated. If it does not meet the load requirements, the third robotic arm 3 is activated, and the suction cup of the rope-driven end effector of the third robotic arm 3 is used to simultaneously adsorb the adsorbed object. If it can meet the load requirements, the fourth robotic arm 4 does not need to be activated. If it does not meet the load requirements, the fourth robotic arm 4 is activated, and the suction cup of the rope-driven end effector of the third robotic arm 4 is used to simultaneously adsorb the adsorbed object. Each time a robotic arm is activated, the bending angle of the rope-driven end effector in the corresponding robotic arm needs to be adjusted.

[0049] In the above embodiments, the bending angle of the rope-driven end effector is the bending angle of the main body of the rope-driven end effector robotic arm. The rope-driven end effector can be a suction cup provided at the end of a rope-driven robotic arm in the prior art. The rope-driven robotic arm can be the robotic arm disclosed in CN118700210A, or other rope-driven robotic arms, as long as it can achieve multi-directional adjustment of the bending degree.

[0050] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A control method using a collaborative robotic arm, characterized in that, The robotic arm includes a first robotic arm, a second robotic arm, a third robotic arm, and a fourth robotic arm. The first robotic arm, the second robotic arm, and the third robotic arm are located on a first track, and the fourth robotic arm is located on a second track. The first track and the second track are arranged in parallel, and both the first track and the second track are straight tracks. Among them, the first robotic arm is the main moving arm, the second robotic arm and the third robotic arm are the following arms, and the fourth robotic arm is the cooperating arm; The second robotic arm and the third robotic arm move closer to the first robotic arm with the first robotic arm as a reference; the second robotic arm maintains a first safe distance from the first robotic arm, and the third robotic arm maintains a second safe distance from the first robotic arm, wherein the second safe distance is greater than or equal to the first safe distance; When the first safety distance is equal to the second safety distance, the second robotic arm and the third robotic arm approach the first robotic arm at the same speed; when the first safety distance is less than the second safety distance, the speed at which the second robotic arm approaches the first robotic arm is greater than the speed at which the third robotic arm approaches the first robotic arm. At this time, the second and third robotic arms are located on the same side of the first robotic arm. When the third robotic arm moves, the second robotic arm has already moved to the first safety distance or is in the process of moving. For safety reasons, the moving speed of the third robotic arm must be less than the moving speed of the second robotic arm. Before starting the operation, the first robotic arm moves to a designated position on the first track, the second robotic arm moves to maintain the first safe distance from the first robotic arm, and the third robotic arm moves to maintain the second safe distance from the first robotic arm; the fourth robotic arm determines its position on the second track based on the positions of the first, second, and third robotic arms. The first, second, third, and fourth robotic arms are all multi-degree-of-freedom serial robotic arms with identical structures. Each of the first, second, third, and fourth robotic arms is equipped with a rope-driven end effector at its end. The first robotic arm and the second robotic arm are each provided with at least two sets of reference points, and the two reference points in each set are respectively located at the two ends of the first robotic arm and the second robotic arm. The first and second moving arms of the second and third robotic arms are each provided with at least two sets of reference points, and the two reference points in each set are respectively located at the two ends of the first and second moving arms. At least two sets of reference points on the first and second moving arms of the second and third robotic arms are respectively set to correspond to at least two sets of reference points on the first and second moving arms of the first robotic arm; The operation begins. The first robotic arm starts to move and controls its end effector to the designated suction point a1. Then the second robotic arm moves and controls its end effector to the designated suction point a2. The third robotic arm moves and controls its end effector to the designated suction point a3. The first, second, and third robotic arms work together to maintain the relative positions of the adsorption points a1, a2, and a3. Adsorption points a1, a2, and a3 are the contact centers between the adsorbed object and the suction cups on the rope-driven end effectors of each robotic arm. The center of gravity of the adsorbed object can be adjusted by adjusting the bending angle of each rope-driven end effector. If, after adjusting the bending angle of the rope-driven end effectors to adjust the center of gravity of the adsorbed object, the first, second, and third robotic arms cannot meet the load requirements, the fourth robotic arm is activated to readjust the center of gravity of the adsorbed object to complete the operation.

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