A four-degree-of-freedom high-speed parallel pickup robot mechanism

Abstract

This invention belongs to the field of parallel robot technology. To address the limited workspace problem of existing four-degree-of-freedom parallel robots, a four-degree-of-freedom high-speed parallel pickup robot mechanism is provided. This mechanism includes a frame, drive components, an active arm, a driven arm, and a moving platform. The frame includes two support units that form a working space for external conveying devices to pass through. Each support unit is equipped with two drive components, and the four drive components are symmetrically distributed in a rectangle. The drive components drive the active arm to rotate in a direction perpendicular to the ground. Each group of driven arms includes two parallel connecting rods and four connecting pairs. The two ends of the two connecting rods are connected to the active arm and the moving platform respectively through the connecting pairs. The moving platform is located above the working space and can perform three-dimensional movement and rotation about an axis perpendicular to the ground. This four-degree-of-freedom high-speed parallel pickup robot mechanism enables a wide range of movement of the moving platform, realizing the adjustment of the material's arbitrary angle and posture.

Description

Technical Field

[0001] This invention belongs to the field of parallel robot technology, and particularly relates to a four-degree-of-freedom high-speed parallel picking robot mechanism. Background Technology

[0002] Parallel robots are mechanisms composed of multiple branches connected in parallel. Their moving platform achieves complex motion trajectories and attitude adjustments through the coordinated movement of these branches. Compared to traditional serial robots, parallel robots offer significant advantages such as higher overall rigidity, higher precision, stronger load capacity, and better dynamic performance. These characteristics have led to their widespread application in fields such as industrial automation, precision machining, aerospace, and medicine.

[0003] Four-degree-of-freedom (DOF) parallel robot mechanisms hold significant research and application value in the field of parallel robotics. They achieve three translational degrees of freedom and one rotational degree of freedom, making them suitable for various complex tasks such as material picking, packaging and sorting, parts processing, and assembly. However, existing four-DOF parallel robot mechanisms still have some limitations in design and application. For example, some mechanisms have limited workspace, making it difficult to meet the needs of large-scale operations; the motion chain designs of some mechanisms are complex, making manufacturing difficult and leading to increased costs and difficulty in guaranteeing accuracy. Furthermore, some existing four-DOF parallel robot mechanisms also lack flexibility. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a four-degree-of-freedom high-speed parallel picking robot mechanism with a large workspace and high applicability.

[0005] This invention provides a four-degree-of-freedom high-speed parallel pickup robot mechanism, comprising:

[0006] The frame includes two support units symmetrically arranged in the horizontal direction, and the two opposing support units form a working space for external conveying devices to pass through;

[0007] There are four driving components, with two driving components on each support unit, and the four driving components are distributed in a rectangular symmetrical manner;

[0008] There are four active arms, each of which is connected to a corresponding drive unit. The drive unit is used to drive the corresponding active arm to rotate, and the rotation axis of the active arm is perpendicular to the ground.

[0009] Four sets of driven arms, each set of driven arms is connected to a corresponding driving arm. Each set of driven arms includes two parallel connecting rods and four connecting pairs. Among the driving member, driving arm and driven arm connected in the same set, the ends of the two connecting rods closer to the driving arm are connected to the ends of the driving arm farther from the driving member through two connecting pairs.

[0010] The moving platform is located above the workspace. The moving platform includes a platform body and two connecting rods. The two connecting rods are symmetrically arranged on the top edge area of ​​the platform body, and each connecting rod is connected to two sets of driven arms connected to the same support unit. In the same set of connecting rods and two sets of driven arms, the end of the connecting rod away from the driving arm is rotatably connected to the connecting rod through a connecting pair. In one set of driven arms and the two connection points of the connecting rod, the lower connection point is closer to the platform body, and the upper connection point is located between the two connection points of the other set of driven arms and the connecting rod.

[0011] The driving component drives the corresponding active arm to rotate in coordination, thereby driving the corresponding driven arm to move in conjunction, enabling the moving platform to perform three-dimensional movement in space and rotation around an axis perpendicular to the ground.

[0012] Optionally, the connection between the driven boom and the driving boom is a ball joint or a Hooke joint, and the connection between the driven boom and the moving platform is a Hooke joint or a ball joint.

[0013] Optionally, the Hooke joint includes two orthogonally arranged first and second revolute joints. The rotation axis of the first revolute joint is perpendicular to the length direction of the connecting rod, and the rotation axis of the second revolute joint is parallel to the rotation axis of the output shaft of the drive member and the axis of the connecting rod.

[0014] Optionally, the ball joint has three rotational degrees of freedom.

[0015] Optionally, the two links in the same driven arm are of the same length, so that the driven arm always maintains the parallelogram motion characteristics during the movement.

[0016] Optionally, a gripping component is provided at the bottom of the platform body for picking up and placing goods.

[0017] The technical solution provided by the embodiments of the present invention has the following beneficial effects compared with the prior art:

[0018] This invention provides a four-degree-of-freedom high-speed parallel picking robot mechanism. By setting two separate and symmetrical support units, a working space is formed for external conveying devices to pass through. This layout not only makes full use of space but also enables the large-scale movement of the moving platform, meeting the needs of large-scale material picking and solving the problem of limited working space in existing parallel robots. Simultaneously, the four driving components in this mechanism are arranged in a rectangular symmetrical pattern, resulting in uniform force distribution. The motion trajectories of the active and driven arms are matched, effectively avoiding singular configurations. This allows the moving platform to perform three-dimensional movement within space and rotation around an axis perpendicular to the ground, enabling arbitrary angle and posture adjustment of materials. It is suitable for high-speed sorting scenarios in multiple industries such as food, electronics, and daily chemicals. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of a four-degree-of-freedom high-speed parallel pickup robot mechanism according to an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram showing the connection between a support unit and a drive member, an active arm, a driven arm, and a moving platform according to an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram showing the connection of the driving arm, driven arm, and moving platform when the connecting pair described in this embodiment of the invention uses a Hooke joint.

[0024] Figure 4 This is a schematic diagram of the connection between the connecting rod and the drive arm when the connecting pair described in this embodiment of the invention uses a Hooke joint;

[0025] Figure 5 This is a schematic diagram of the connection between the connecting rod and the connecting rod when the connecting pair described in this embodiment of the invention uses a Hooke joint;

[0026] Figure 6 This is a schematic diagram showing the connection of the driving member, the driving arm, the driven arm, and the moving platform when the connecting pair described in this embodiment of the invention uses a ball joint;

[0027] Figure 7 This is a schematic diagram illustrating the operation of a four-degree-of-freedom high-speed parallel picking robot mechanism for adjusting the posture of products on a production line, as described in an embodiment of the present invention.

[0028] Among them, 1. Support unit; 2. Drive component; 3. Active arm; 4. Driven arm; 41. Connecting rod; 42. Hooke joint; 421. First revolute joint; 422. Second revolute joint; 43. Ball joint; 5. Moving platform; 51. Platform body; 52. Connecting rod. Detailed Implementation

[0029] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0030] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0031] Reference Figure 1 As shown, this embodiment provides a four-degree-of-freedom high-speed parallel picking robot mechanism, including a frame, four drive components 2, four active arms 3, four sets of driven arms 4, and a moving platform 5.

[0032] The frame includes two support units 1 arranged symmetrically in the horizontal direction. The two support units 1 form a working space for the external conveying device to pass through. That is, the two support units 1 are arranged symmetrically in the left and right directions perpendicular to the movement direction of the external conveying device, and the bottom of the two support units 1 are connected to the ground.

[0033] The drive component 2 is a rotary motor. Each support unit 1 has two drive components 2 on its top. The four drive components 2 are distributed in a rectangular symmetrical pattern. The symmetrical layout makes it easier to coordinate the power output and motion trajectory of the four drive components 2. Without the need for complex algorithms to adjust the parameters of a single drive component 2, the linear movement and precise positioning of the moving platform 5 indirectly connected to it can be achieved. Each active arm 3 is connected to a corresponding drive component 2. The active arm 3 is connected to the output shaft of the drive component 2. Under the drive of the drive component 2, the active arm 3 rotates around an axis perpendicular to the ground.

[0034] Reference Figure 2 and Figure 3 As shown, each group of driven booms 4 is connected to a corresponding driving boom 3. Each group of driven booms 4 includes two parallel connecting rods 41 and four connecting pairs. Among the driving member 2, driving boom 3 and driven boom 4 connected in the same group, the ends of the two connecting rods 41 near the driving boom 3 are connected to the ends of the driving boom 3 away from the driving member 2 through two connecting pairs. The moving platform 5 is located above the working space. The moving platform 5 includes a platform body 51 and two connecting rods 52. The two connecting rods 52 are symmetrically arranged in the top edge area of ​​the platform body 51, and each connecting rod 52 is connected to the same support. The two sets of driven arms 4 on the support unit 1 are connected to each other. In the connecting rod 52 and the two sets of driven arms 4 connected in the same group, the end of the connecting rod 41 away from the active arm 3 is rotatably connected to the connecting rod 52 through the connecting pair. In addition, among the two connection points of one set of driven arms 4 and the connecting rod 52, the lower connection point is closer to the platform body 51, and the upper connection point is between the two connection points of the other set of driven arms 4 and the connecting rod 52. This improves the compactness between the four sets of driven arms 4 and the moving platform 5, thereby improving the rigidity of this four-degree-of-freedom high-speed parallel picking robot mechanism.

[0035] The connection between the driven arm 4 and the driving arm 3 is a ball joint 43 or a Hooke joint 42, and the connection between the driven arm 4 and the moving platform 5 is a Hooke joint 42 or a ball joint 43. The Hooke joint 42 includes two orthogonally arranged first revolute joints 421 and second revolute joints 422. The two orthogonally arranged revolute joints effectively distribute the stress during the motion process and ensure the stability of the mechanism during high-speed motion. The rotation axis of the first revolute joint 421 is perpendicular to the length direction of the connecting rod 41, and the rotation axis of the second revolute joint 422 is parallel to the rotation axis of the output shaft of the driving member 2 and the axis of the connecting rod 52. The ball joint 43 has three rotational degrees of freedom.

[0036] Reference Figure 4 and Figure 5 As shown, the connection between the driven boom 4 and the driving boom 3 is a Hooke hinge 42, and the connection between the driven boom 4 and the moving platform 5 is also a Hooke hinge 42. (Refer to...) Figure 6 As shown, the connection between the driven arm 4 and the driving arm 3 is a ball joint 43, and the connection between the driven arm 4 and the moving platform 5 is a ball joint 43. The two ends of the connecting rod 41 are connected to the driving arm 3 and the connecting rod 52 respectively through the ball joint 43, which further improves the motion freedom of the driven arm 4 and reduces the jamming and interference of the connecting rod 41 during the movement. This allows the driven arm 4 to adjust its posture more freely when it rotates with the driving arm 3, thereby enabling the moving platform 5 to achieve more complex posture adjustments in three-dimensional space and meet the picking needs of goods of different shapes and sizes. In actual production, the type of connecting pair can be flexibly selected according to task requirements, or a combination of Hooke joint 42 and ball joint 43 can be used. Specifically, the connecting pair between the driven arm 4 and the driving arm 3 is a ball joint 43, and the connecting pair between the driven arm 4 and the moving platform 5 is a Hooke joint 42, or the connecting pair between the driven arm 4 and the driving arm 3 is a Hooke joint 42, and the connecting pair between the driven arm 4 and the moving platform 5 is a ball joint 43. The above two types of connecting pairs are not shown in the attached figure. By flexibly adjusting the configuration of the connecting pairs, the four-degree-of-freedom high-speed parallel picking robot mechanism can adjust its motion characteristics according to different working environments and task requirements to achieve the best working effect.

[0037] Reference Figure 3 As shown, the two links 41 in the same driven arm 4 have the same length. This design enables the driven arm 4 to maintain the parallelogram motion characteristics during the movement, which effectively improves the motion accuracy and stability of the four-degree-of-freedom high-speed parallel picking robot mechanism.

[0038] When this four-degree-of-freedom high-speed parallel picking robot is working, the external conveying device transports the goods to the work space. The four drive components 2 work together according to the preset program to drive the corresponding active arm 3 to rotate. The active arm 3 drives the driven arm 4 connected to it to move in linkage. Due to the parallelogram motion characteristics of the driven arm 4 and the role of the connecting pair, the moving platform 5 can perform precise three-dimensional movement in space and rotate around the axis perpendicular to the ground.

[0039] The bottom of the platform body 51 is equipped with a gripping component, which is a suction cup or gripper that can pick up goods. The gripping component can accurately pick up, adjust the posture and place the goods according to the preset program or visual sensor feedback, thereby realizing the efficient and accurate operation of the four-degree-of-freedom high-speed parallel picking robot mechanism on the automated production line.

[0040] Specifically, the driving component 2 drives the corresponding active arm 3 to rotate in coordination, thereby driving the corresponding driven arm 4 to move in tandem, enabling the moving platform 5 to perform three-dimensional movement in space and rotation around an axis perpendicular to the ground. This includes three-dimensional movement along the X-axis (conveyor direction), Y-axis (horizontal direction), and Z-axis (vertical direction) in space, and one-dimensional rotation around the Z-axis (vertical direction, i.e., perpendicular to the ground). When the gripping component is a suction cup, the suction cup adsorbs the goods through vacuum suction. Suction cups are suitable for goods with flat surfaces and uniform texture. A vision sensor is fixed at the center of the bottom of the suction cup. A center reference mark is preset on the surface of the goods. The vision sensor collects images of the center reference mark, calculates the pixel coordinates of the center reference mark using an image algorithm, and then converts the pixel coordinates into actual physical coordinates. The vision sensor transmits this information to the control system. The control system precisely controls the coordinated movement of the four driving components 2 based on this information, comparing the coordinate deviation between the center of the suction cup and the center of the goods. If the deviations in the X-axis and Y-axis directions are both 0, then the vertical center axis of the suction cup coincides with that of the goods. At this time, the moving platform 5... The suction cup is accurately moved above the goods. The four drive components 2 continue to move in coordination. The drive components 2 drive the active arm 3 to rotate, which drives the driving platform 5 to descend along the Z-axis through the connecting pair on the driven arm 4 until the suction cup contacts the goods. The control system activates the vacuum device, which causes the suction cup to generate suction to adsorb the goods. During the adsorption process, the air inside the suction cup is extracted to form a negative pressure environment, thereby firmly fixing the goods to the suction cup. In order to ensure the stability of the suction cup, the material and number of suction cups need to be selected according to the characteristics of the goods. For goods with rough surfaces, rubber suction cups with good elasticity and sealing performance can be selected; for goods with irregular shapes, multiple small suction cups can be combined to adsorb the goods.

[0041] Reference Figure 7 As shown, the working process of this four-degree-of-freedom high-speed parallel picking robot mechanism includes four steps, as described above. Figure 7As shown in (a), during initial positioning, the external conveyor transports the goods to the preset pickup position. The control system sends a position signal for the goods, and the four drive components 2 move in tandem, driving the platform 5 to move along the X and Y axes to directly above the goods; (Refer to...) Figure 7 As shown in (b), to grasp the goods, the drive unit 2 drives the active arm 3 to rotate, which in turn drives the driven platform 5 to descend along the Z-axis through the connecting pair on the driven arm 4 until the grasping component contacts the goods, and the grasping component grasps the goods; see reference. Figure 7 As shown in (c), the posture adjustment is achieved by the control system driving two drive components 2 on the same side to rotate in opposite directions according to sorting requirements. These two drive components 2 then drive the corresponding active arms 3 to rotate in opposite directions, which in turn drive the driven arms 4, causing the moving platform 5 to rotate around the Z-axis. This adjusts the posture of the goods to meet the requirements of subsequent sorting or placement. (Refer to...) Figure 7 As shown in (d), after placement and reset, and posture adjustment, the drive unit 2 drives the moving platform 5 to descend along the Z-axis until the goods are placed at the required location. Finally, the four drive units 2 move in tandem to drive the moving platform 5 back to the initial position, completing one picking and sorting cycle.

[0042] The four-degree-of-freedom high-speed parallel picking robot mechanism provided in this embodiment of the invention forms a working space for external conveying devices to pass through by setting two separate and symmetrical support units 1. This layout not only makes full use of space, but also provides the possibility for the large-scale movement of the moving platform 5, which can meet the needs of large-scale material picking and solves the problem of limited working space of existing parallel robots.

[0043] In the prior art, some parallel robots are prone to singular configurations during movement due to the asymmetrical arrangement of the drive components 2, and the overall rigidity is insufficient, making them prone to deformation under load. However, in this four-degree-of-freedom high-speed parallel pickup robot mechanism, the four drive components 2 are arranged in a rectangular symmetrical manner, resulting in uniform force distribution. The motion trajectories of the active arm 3 and the driven arm 4 are matched with each other, which can effectively avoid singular configurations.

[0044] This four-degree-of-freedom high-speed parallel picking robot mechanism has four degrees of freedom: three-dimensional movement and rotation around the Z-axis. The rotation range around the Z-axis is ±180°, which can realize the adjustment of the material's angle and posture. It can be adapted to high-speed sorting scenarios in multiple industries such as food, electronics, and daily chemicals.

[0045] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0046] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A four-degree-of-freedom high-speed parallel picking robot mechanism, characterized in that, include: The frame includes two support units (1) arranged symmetrically in the horizontal direction, and the two opposing support units (1) form a working space for external conveying devices to pass through; Four driving components (2), two driving components (2) are provided on each support unit (1), and the four driving components (2) are distributed in a rectangular symmetrical manner; Four active arms (3), each active arm (3) is connected to a corresponding drive unit (2), the drive unit (2) is used to drive the corresponding active arm (3) to rotate, and the rotation axis of the active arm (3) is perpendicular to the ground; Four sets of driven arms (4), each set of driven arms (4) is connected to a corresponding driving arm (3), each set of driven arms (4) includes two parallel connecting rods (41) and four connecting pairs; among the driving member (2), driving arm (3) and driven arm (4) connected in the same set, the end of the two connecting rods (41) near the driving arm (3) is connected to the end of the driving arm (3) away from the driving member (2) through two connecting pairs; The moving platform (5) is located above the work space. The moving platform (5) includes a platform body (51) and two connecting rods (52). The two connecting rods (52) are symmetrically arranged on the top edge area of ​​the platform body (51), and each connecting rod (52) is connected to two sets of driven arms (4) connected to the same support unit (1). Among the connecting rods (52) and the two sets of driven arms (4) connected in the same group, the end of the connecting rod (41) away from the active arm (3) is rotatably connected to the connecting rod (52) through a connecting pair. Among the two connection points of one set of driven arms (4) and the connecting rod (52), the lower connection point is closer to the platform body (51), and the upper connection point is between the two connection points of the other set of driven arms (4) and the connecting rod (52). The connection between the driven boom (4) and the driving boom (3) is a ball joint (43) or a Hooke joint (42), and the connection between the driven boom (4) and the moving platform (5) is a Hooke joint (42) or a ball joint (43). The driving component (2) drives the corresponding active arm (3) to rotate in coordination, thereby driving the corresponding driven arm (4) to move in three dimensions in space and rotate around an axis perpendicular to the ground.

2. A four-degree-of-freedom high-speed parallel picking robot mechanism according to claim 1, characterized in that, The Hooke joint (42) includes two orthogonally arranged first revolute joints (421) and second revolute joints (422). The rotation axis of the first revolute joint (421) is perpendicular to the length direction of the connecting rod (41), and the rotation axis of the second revolute joint (422) is parallel to the rotation axis of the output shaft of the drive member (2) and the axis of the connecting rod (52).

3. A four-degree-of-freedom high-speed parallel picking robot mechanism according to claim 1, characterized in that, The ball joint (43) has three rotational degrees of freedom.

4. A four-degree-of-freedom high-speed parallel picking robot mechanism according to claim 1, characterized in that, The two connecting rods (41) in the same driven arm (4) have the same length, so that the driven arm (4) always maintains the parallelogram motion characteristics during the motion.

5. A four-degree-of-freedom high-speed parallel picking robot mechanism according to claim 1, characterized in that, The bottom of the platform body (51) is equipped with a gripping component, which is used to pick up and place goods.

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