Double-arm ball throwing and receiving robot

Abstract

The double-arm ball throwing and receiving robot comprises a supporting framework, a ball throwing and receiving mechanism, a visual sensor, a ball falling mechanism and a central processing unit, the ball throwing and receiving mechanism comprises a left mechanical arm and a right mechanical arm which are symmetrically arranged, the mechanical arms are arm-like mechanical arms, and the execution tail ends of the mechanical arms are provided with tail end executors; the mounting position of the ball falling mechanism is higher than that of the mechanical arm, and the visual sensor is located at the top end or the bottom end of the supporting framework; in the overlook direction, the ball throwing and receiving mechanism and the visual sensor are both located between the two sets of mechanical arms. According to the double-arm ball throwing and receiving robot, the layout of the double mechanical arms, the visual sensor and the ball falling mechanism is reasonable, complex three-dimensional throwing and receiving actions can be completed, ball throwing and receiving tasks in various task modes can be carried out, various use and display requirements are met, and the action diversity and the environmental adaptability are enhanced.

Description

Technical Field

[0001] This utility model relates to the field of robotics technology, and in particular to a dual-arm ball-throwing and catching robot. Background Technology

[0002] In the field of robotics, ball-throwing and catching robots have become a research hotspot due to their potential applications in entertainment, education, and other scenarios. Existing technologies have various ball-throwing and catching robot designs, but they still suffer from insufficient flexibility and limited dynamic response capabilities. Patent CN 110111623 A proposes a ball-throwing unit that uses a two-axis translation unit to drive the ball bowl to move in a vertical plane, combined with a ball-dropping mechanism to achieve self-throwing and self-catching of a single ball. While its technical solution supports basic throwing and catching tasks, it has significant drawbacks: (1) The two-axis translation mechanism can only achieve simple throwing and catching actions in a plane, lacking three-dimensional spatial motion capabilities and unable to simulate the complex movements of the human arm; (2) The end effector has a single function, and the fixed ball bowl is only suitable for balls of specific shapes, unable to be extended to grasping scenarios involving irregular objects or different materials; (3) It has poor adaptability to dynamic tasks, the control logic relies on pre-programmed paths, lacks a real-time feedback adjustment mechanism, and is difficult to cope with sudden changes in ball trajectory or parallel tasks involving multiple balls. Patent CN206154324 U discloses a three-axis ball-throwing and catching robot that sorts balls using a three-axis linkage frame and an industrial camera. While this technical solution improves the applicability to industrial scenarios, it also suffers from drawbacks such as insufficient degrees of freedom in the robotic arm, limitations in the vision system, and rigid control algorithms. The applicant's earlier application CN221736194U provides a multi-degree-of-freedom humanoid arm ball-throwing and catching robot, which, although possessing high degrees of freedom, can only perform relatively simple tasks.

[0003] It is evident that while existing ball-throwing and catching robots address basic task requirements to some extent, limitations in their mechanical structure, sensing systems, and control logic result in insufficient flexibility, scalability, and dynamic task processing capabilities. Significant technological gaps exist, particularly in biomimetic motion, multi-target cooperative operation, and high-precision real-time control. Utility Model Content

[0004] Purpose of the utility model: In order to overcome the shortcomings of the existing technology, this utility model provides a dual-arm ball-throwing and catching robot with a biomimetic dual-arm structure that can perform a variety of tasks to meet the application scenarios and task requirements.

[0005] Technical solution: To achieve the above objectives, the present invention provides a dual-arm ball-throwing and catching robot, comprising a support frame, a ball-throwing and catching mechanism, a vision sensor, a ball-dropping mechanism, and a central processing unit.

[0006] The ball-throwing and catching mechanism includes two robotic arms symmetrically arranged on the left and right. The robotic arms are arm-like robotic arms, and the end effector of each robotic arm has an end effector. The ball-dropping mechanism is installed above the robotic arms, and the vision sensor is located at the top or bottom of the support frame. In a top view, both the ball-throwing and catching mechanism and the vision sensor are located between the two sets of robotic arms.

[0007] Furthermore, the robotic arm has a 6-degree-of-freedom joint structure, which includes a shoulder rotation joint, a shoulder joint, an elbow rotation joint, an elbow joint, a wrist rotation joint, and a wrist joint in sequence. The robotic arm also includes an upper arm and a forearm. The two ends of the upper arm are respectively connected to the elbow rotation joint and the elbow joint, and the two ends of the forearm are respectively connected to the wrist rotation joint and the wrist joint. The end effector is connected to the wrist joint.

[0008] Furthermore, the end effector is a replaceable modular component configured to connect to the wrist joint via a quick interface; the end effector is in the form of a bowl-shaped container, a gripper, or a suction cup, used to grasp, hold, and release a sphere.

[0009] Furthermore, the ball-dropping mechanism includes a mounting base, on which a ball cylinder and a release mechanism are mounted. The release mechanism includes a first baffle and a second baffle that can open and close relative to each other. The first baffle and the second baffle each have a gear portion, and the gear portions on the two baffles mesh with each other. The first baffle can be driven to rotate by a motor or a cylinder.

[0010] Furthermore, the support frame has an I-shaped main body, with the two robotic arms positioned at both ends of the upper crossbeam of the main body; the support frame also includes a ball-dropping mechanism bracket extending upward from the upper side of the main body, and a support leg extending downward from the lower side of the main body.

[0011] Beneficial effects: The dual-arm ball-throwing and catching robot of this utility model has the following beneficial effects:

[0012] (1) The layout of the dual robotic arms, vision sensors and ball-dropping mechanism in the dual-arm ball-throwing and catching robot is reasonable. The 6-DOF robotic arms are used to simulate the movement of human arms. The high degree of freedom of movement breaks through the limitation of translation axis in the existing technology. It can complete complex three-dimensional throwing and catching actions (such as arc throwing and dynamic catching) and can perform ball-throwing and catching tasks in various task modes, meeting the needs of various uses and demonstrations, and enhancing the diversity of actions and environmental adaptability.

[0013] (2) By adapting different types of end effectors to the quick interface as needed, various types of ball throwing and catching operations can be realized, making the robot's functions more diverse and solving the problem of the single function of fixed end effectors.

[0014] (3) In the ball throwing and catching control method, the starting posture and motion path of the robotic arm are dynamically adjusted based on the task type, and closed-loop control is achieved by combining visual feedback. It supports intelligent switching of multiple task modes, improves throwing and catching efficiency and success rate, and meets diverse application needs.

[0015] (4) By using trajectory prediction and joint coordinated control, the position of the end effector is adjusted in real time to buffer kinetic energy, stabilize ball reception and prevent the ball from falling out, thus solving the problem of ball reception failure caused by mechanical delay in the prior art.

[0016] (5) The dual-arm alternating ball throwing and catching task and the multi-ball cyclic throwing and catching task break through the existing single-ball handling mode. In the multi-ball cyclic throwing and catching, the intermittent ball drop and the coordinated control of the dual arms balance the throwing and catching frequency and the task load, and efficiently handle multi-ball parallel tasks. Attached Figure Description

[0017] Figure 1 This is a structural diagram of a two-armed ball-throwing and catching robot;

[0018] Figure 2 This is a structural diagram of the ball-dropping mechanism;

[0019] Figure 3 This is a structural diagram of the robotic arm and its end effector;

[0020] Figure 4(a) and Figure 4(b) show the intermediate and completed states of the robotic arm stabilizing the ball after receiving it.

[0021] Figures 5(a), 5(b), and 5(c) are state diagrams of the robotic arm throwing the ball.

[0022] Figure 6 This is a flowchart illustrating the ball-throwing and catching control method.

[0023] In the diagram: 1-Supporting frame; 11-Main body; 12-Ball dropping mechanism bracket; 13-Outrigger; 2-Ball throwing and catching mechanism; 21-Robotic arm; 21a-Shoulder rotation joint; 21b-Shoulder joint; 21c-Elbow rotation joint; 21d-Upper arm; 21e-Elbow joint; 21f-Wrist rotation joint; 21g-Forearm; 21h-Wrist joint; 22-End effector; 3-Vision sensor; 4-Ball dropping mechanism; 41-Mounting base; 42-Ball cylinder; 43-First baffle; 44-Second baffle; 45-Motor. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings.

[0025] like Figure 1 The dual-arm ball-throwing and catching robot shown includes a support frame 1, a ball-throwing and catching mechanism 2, a vision sensor 3, a ball-dropping mechanism 4, and a central processing unit.

[0026] The ball-throwing and catching mechanism 2 includes two symmetrically arranged robotic arms 21, each robotic arm 21 being a type of arm-like robotic arm. Each robotic arm 22 has an end effector 22 at its end. The ball-throwing and catching mechanism 2 is mounted higher than the robotic arms 21. The vision sensor 3 is located at the top or bottom of the support frame 1; in this embodiment, the vision sensor 3 is located at the bottom of the support frame 1. In a top-down view, both the ball-throwing and catching mechanism 2 and the vision sensor 3 are located between the two sets of robotic arms 21. The vision sensor 3 is a binocular vision sensor, covering the entire field of view of the robot's operating area, used to identify and track the position and trajectory of multiple balls in real time. The optimal placement of the vision sensor 3 depends on the application scenario; for example, mounting it above provides full coverage, facilitating the capture of ball trajectories; mounting it below helps with close-range detail recognition.

[0027] The central processing unit is an industrial control PC host, which can perform the following functions:

[0028] Based on data from binocular vision sensors, the collaborative throwing and catching path of the two arms is dynamically planned;

[0029] By synchronously driving the joint movements of two robotic arms through a multi-joint collaborative control algorithm, the system can achieve actions such as single ball self-throwing and catching, alternating ball throwing by both arms, cyclic ball throwing and catching, human-machine collaborative interactive ball throwing and catching, and ball throwing in a specified direction.

[0030] Preferably, such as Figure 3 As shown, the robotic arm includes a shoulder rotation joint, a shoulder joint, an elbow rotation joint, an elbow joint, a wrist rotation joint, and a wrist joint. The robotic arm also includes an upper arm and a forearm. The two ends of the upper arm are respectively connected to the elbow rotation joint and the elbow joint, and the two ends of the forearm are respectively connected to the wrist rotation joint and the wrist joint. The end effector 22 is connected to the wrist joint 21h.

[0031] Among them, shoulder rotation joint 21a is responsible for the up-and-down swinging motion of the entire robotic arm, similar to the up-and-down movement of a human shoulder; shoulder joint 21b is used to control the left-and-right swinging motion of the robotic arm to simulate the left-and-right movement of a human arm; elbow rotation joint 21c allows the robotic arm below the shoulder joint to rotate around an axis, providing additional flexibility; elbow joint 21e allows the forearm 21g to swing up and down, achieving movements similar to a human forearm; wrist rotation joint 21f allows the part below the forearm 21g to rotate as a whole, further increasing the reach and angle of the end effector 22; wrist joint 21h allows the end effector to move up and down, ensuring that it can accurately adjust its position to throw or catch a ball.

[0032] The dual-arm ball-throwing and catching robot described above has a reasonable layout of dual robotic arms 21, vision sensors 3, and ball-dropping mechanism 4. The 6-DOF robotic arms 21 are used to simulate the movement of human arms, with a high degree of freedom of movement. This breaks through the limitations of translation axes in existing technologies and can complete complex three-dimensional throwing and catching actions (such as arc throwing and dynamic catching). It can also perform ball-throwing and catching tasks in various task modes, meeting various needs for use and demonstration, and enhancing the diversity of actions and environmental adaptability.

[0033] Preferably, the end effector 22 is a replaceable modular component configured to connect to the wrist joint 21h via a quick-connect interface. The end effector 22 is in the form of a bowl-shaped container, a gripper, or a suction cup, used for grasping, holding, and releasing spheres. The bowl-shaped container is suitable for the stable catching and throwing of standard spheres (such as ping-pong balls, tennis balls, rubber balls, etc., which are elastic, or hollow steel balls, etc., which are non-elastic). The gripper is suitable for grasping various regular and irregular objects, and the suction cup can be used for grasping spheres with smooth surfaces. By adapting different shapes of end effectors 22 as needed through the quick-connect interface, various sphere throwing and catching operations can be achieved, enriching the robot's functionality and solving the problem of the single function of fixed end effectors.

[0034] Preferably, such as Figure 2 As shown, the ball-dropping mechanism 4 includes a mounting base 41, on which a ball cylinder 42 and a release mechanism are mounted. The release mechanism includes a first baffle 43 and a second baffle 44 that can open and close relative to each other. Both the first baffle 43 and the second baffle 44 have gear portions that mesh with each other. The first baffle 43 can be driven to rotate by a motor 45 or a cylinder. The motor 45 or cylinder causing the first baffle 43 to rotate allows the two to open and close relative to each other, releasing the ball from the ball cylinder 42. The aforementioned gear-meshing baffles and motor drive achieve precise ball release, ensuring a controllable ball drop path, improving ball supply stability and task continuity, and avoiding the lag or jamming problems of ball supply mechanisms in the prior art.

[0035] Preferably, the support frame 1 has an I-shaped main body 11, and the two robotic arms 21 are respectively placed at both ends of the upper crossbeam of the main body 11; the support frame 1 also includes a ball dropping mechanism bracket 12 extending upward from the upper side of the main body 11, and a support leg 13 extending downward from the lower side of the main body 11.

[0036] Based on the above-mentioned ball-throwing and catching robot control method, such as Figure 6 As shown, the method includes the following steps S101-S104:

[0037] Step S101: Obtain task information. The target tasks corresponding to the task information include single ball self-throwing and catching, double arm alternating ball throwing, multi-ball cyclic throwing and catching, human-computer collaborative interactive ball throwing and catching, and ball throwing in a specified direction.

[0038] Step S102: Move the left and right robotic arms 21 to the preset starting position to ensure that the end effector 22 is in the optimal position for quick response to the arrival of the ball;

[0039] In this step, the initial pose is set based on the type of task to determine the initial pose of the robotic arm 21;

[0040] Step S103: The visual sensor 3 captures images of the operating area in real time and identifies motion parameters such as the position, speed and direction of motion of the sphere.

[0041] Step S104: Based on the task information and the motion parameters, determine the motion path of the target robotic arm and control the target robotic arm to perform throwing and catching actions to achieve the target task. The target robotic arm can be one of the robotic arms 21 or two robotic arms 21. When executing the target task, the central processing unit can dynamically determine which robotic arm 21 is the target robotic arm, or determine that both robotic arms 21 are the target robotic arms.

[0042] The ball in step S104 can be launched by the ball-dropping mechanism 4, caught by the robotic arm 21 itself, or launched by an external person or the serving mechanism. When the ball is launched by the ball-dropping mechanism 4, steps S102 and S103 further include the following step: controlling the ball-dropping mechanism 4 to launch the ball. In step S104, the robotic arm 21 that can catch the ball the fastest can be selected as the target robotic arm, and the robotic arm 21 is controlled to adjust its posture based on the trajectory of the falling ball to prepare to catch the falling ball. After the end effector 22 catches the ball, the robotic arm 21 is controlled to perform fine-tuning and buffering to achieve balance and stability of the ball in the end effector 22.

[0043] Among them, the single ball self-throwing and self-catching task is completed by a single robotic arm 21, the multi-ball cyclic throwing and catching task is completed by two robotic arms 21, and the ball throwing action in a specified direction is completed by a single robotic arm.

[0044] The above method dynamically adjusts the starting pose and motion path of the robotic arm based on the task type, and combines visual feedback to achieve closed-loop control, supports intelligent switching of multiple task modes, improves throwing and catching efficiency and success rate, and meets diverse application needs.

[0045] Preferably, the step S103 above, which involves controlling the target robotic arm to perform the ball-catching action, includes the following steps S201-S202:

[0046] Step S201: Based on the motion parameters, predict the trajectory of the ball and plan the catching point and the catching path of the target robotic arm; the planning of the catching path includes the planning of motion parameters for each joint in the robotic arm 21; the ball is thrown by a human hand (corresponding to a human-machine collaborative ball throwing and catching task), or released by the ball dropping mechanism 4, or thrown by another ball throwing and catching mechanism 2 (corresponding to a dual-arm alternating ball throwing and catching task and a multi-ball cyclic throwing and catching task), or thrown by the current ball throwing and catching mechanism 2 itself (corresponding to a self-throwing and self-catching task);

[0047] Step S202: Based on the ball-receiving path, control the coordinated movement of each joint of the target robotic arm to bring the end effector 22 to the ball-receiving point to receive the ball and stabilize the ball so that it remains within the end effector 22. Specifically, when the end effector 22 is a ball-and-socket type, in order to stabilize the ball, the joints of the robotic arm 21 operate in coordination, such as... Figure 3 As shown in Figures 4(a) and 4(b), the position of the end effector 22 is finely adjusted in the direction of the incoming ball to buffer the kinetic energy of the ball and prevent the ball from bouncing out of the bowl due to collision with the bowl.

[0048] In the above ball-catching step, the position of the end effector is adjusted in real time to buffer kinetic energy through trajectory prediction and joint coordinated control, so as to stabilize the ball-catching and prevent the ball from falling out, thus solving the problem of ball-catching failure caused by mechanical delay in the prior art.

[0049] Preferably, the step S103 above, which involves controlling the target robotic arm to throw the ball, includes the following steps S301-S302:

[0050] Step S301: Determine the target location based on the target task and plan the ball throwing point and ball throwing trajectory; wherein, the target location may be the ball throwing and catching mechanism 2 on the other side or the current ball throwing and catching mechanism 2 (corresponding to the task of throwing the ball in turn by both arms, multi-ball cyclic throwing and catching, or self-throwing and self-catching), a specific area (such as a table tennis table or target field, corresponding to the task of throwing the ball in a specified direction), or a specific target (such as a human hand when performing human-machine collaborative interactive ball throwing and catching).

[0051] Step S302: Based on the ball-throwing point and trajectory, plan the motion parameters of each joint in the target robotic arm, and control the operation of each joint accordingly to adjust the ball-throwing angle and force of the end effector 22; when the end effector 22 is in the form of a gripper, suction cup, etc., it releases the ball after reaching the ball-throwing point. The ball-throwing process is as follows: Figures 5(a)-5(c) As shown.

[0052] After the ball is released, the vision sensor 3 continuously tracks the trajectory of the ball. If the robotic arm 21 needs to catch the ball again, the system will update and adjust the position of the robotic arm 21 in real time if the actual movement trajectory does not match the expectation, so as to ensure the successful ball catching action.

[0053] Preferably, the step S301 above, which involves planning the ball trajectory according to the target task, includes: calculating the initial velocity and angle of the ball based on the target position;

[0054] The motion parameters of each joint are determined based on the inverse kinematics model. The inverse kinematics model quickly calculates joint parameters, reduces path planning time, improves dynamic task response speed, and ensures the continuity and efficiency of throwing and catching actions, outperforming the computational efficiency of existing interpolation algorithms.

[0055] Preferably, when performing the task of alternately throwing and catching the ball with both arms, the specific steps include the following: S401-S405:

[0056] Step S401: Set the robotic arm 21 with a ball in the corresponding end effector 22 as the ball throwing robotic arm and the other robotic arm 21 as the ball catching robotic arm, and restore both robotic arms 21 to their initial state; when there is no ball in the end effector 22 corresponding to both robotic arms 21 and the ball dropping mechanism 4 needs to release the ball, first designate one robotic arm 21 to catch the ball released by the ball dropping mechanism 4, and then designate that robotic arm 21 as the ball throwing robotic arm;

[0057] Step S402: Control the end effector 22 corresponding to the ball-throwing robot arm to tilt downwards and enter the ball-throwing state; then, control the ball-throwing robot arm to move the end effector 22 diagonally upwards and throw the ball at the preset ball-throwing point;

[0058] Step S403: Based on the image collected by the vision sensor 3, track the real-time trajectory of the ball and determine the ball-catching point and the ball-catching trajectory of the ball-catching robotic arm.

[0059] Step S404: Control the movement of the ball-receiving robotic arm so that its corresponding end effector 22 contacts the ball, and control the ball-receiving robotic arm to stabilize the ball after the ball enters the end effector 22;

[0060] Step S405: Exchange the roles of the two robotic arms 21 and repeat the above steps.

[0061] The above-mentioned task of alternating throwing and catching of the ball with both arms can achieve coordinated movement of both arms, breaking through the existing single-ball handling mode.

[0062] Preferably, when performing a multi-ball cyclic throwing and catching task, the specific steps include the following: S501-S504:

[0063] Step S501: Control the ball dropping mechanism 4 to drop balls intermittently;

[0064] In step S502, control the two robotic arms 21 to perform the actions of catching and throwing the ball in a cycle. After the ball-dropping mechanism 4 releases a new ball, control one of the robotic arms 21 to catch the newly released ball and throw the newly released ball to the catching point of the other robotic arm 21. Adjust the catching and throwing frequency of the two robotic arms 21.

[0065] The aforementioned tasks involving alternating ball tossing and catching with both arms, as well as multi-ball cyclic tossing and catching, break through the existing single-ball handling mode. In multi-ball cyclic tossing and catching, the intermittent ball drop and coordinated control of both arms balance the tossing and catching frequency and the task load, efficiently handling multiple parallel tasks.

[0066] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A dual-arm ball-throwing and catching robot, comprising a support frame (1), a ball-throwing and catching mechanism (2), a vision sensor (3), a ball-dropping mechanism (4), and a central processing unit, characterized in that: The ball-throwing and catching mechanism (2) includes two robotic arms (21) arranged symmetrically on the left and right. The robotic arms (21) are arm-like robotic arms, and the execution end of the robotic arms (21) has an end effector (22). The ball-dropping mechanism (4) is installed higher than the robotic arms (21), and the vision sensor (3) is located at the top or bottom of the support frame (1). In the top view direction, the ball-throwing and catching mechanism (2) and the vision sensor (3) are both located between the two sets of robotic arms (21).

2. The dual-arm ball-throwing and catching robot according to claim 1, characterized in that, The robotic arm (21) has a 6-degree-of-freedom joint structure, which includes, in sequence, a shoulder rotation joint (21a), a shoulder joint (21b), an elbow rotation joint (21c), an elbow joint (21e), a wrist rotation joint (21f), and a wrist joint (21h). The robotic arm (21) also includes an upper arm (21d) and a forearm (21g). The two ends of the upper arm (21d) are respectively connected to the elbow rotation joint (21c) and the elbow joint (21e), and the two ends of the forearm (21g) are respectively connected to the wrist rotation joint (21f) and the wrist joint (21h). The end effector (22) is connected to the wrist joint (21h).

3. The dual-arm ball-throwing and catching robot according to claim 2, characterized in that, The end effector (22) is a replaceable modular component configured to connect to the wrist joint (21h) via a quick interface; the end effector (22) is in the form of a bowl-shaped container, a gripper or a suction cup, used to grasp, hold and release a sphere.

4. The dual-arm ball-throwing and catching robot according to claim 1, characterized in that, The ball dropping mechanism (4) includes a mounting base (41), on which a ball cylinder (42) and a release mechanism are mounted. The release mechanism includes a first baffle (43) and a second baffle (44) that can open and close relative to each other. The first baffle (43) and the second baffle (44) each have a gear portion, and the gear portions on both are meshed with each other. The first baffle (43) can be driven to rotate by a motor (45) or a cylinder.

5. The dual-arm ball-throwing and catching robot according to claim 1, characterized in that, The support frame (1) has an I-shaped main body (11), and two robotic arms (21) are placed at both ends of the upper crossbeam of the main body (11); the support frame (1) also includes a ball-dropping mechanism bracket (12) extending upward from the upper side of the main body (11), and a support leg (13) extending downward from the lower side of the main body (11).

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