A three-axis parallel manipulator

Abstract

The utility model is suitable for sorting instrument technical field provides a kind of three-axis parallel mechanical arm, including installation base and three motors of equal angle arrangement on installation base, the output end of each motor is all fixedly connected with main arm, each main arm is connected with corresponding group of auxiliary arm by first joint, three groups of auxiliary arm are connected with same execution piece mounting table by second joint, and the execution piece mounting table is used to install execution piece, the beneficial effects of the utility model embodiment are: the mechanical arm of three-axis structure is relative to six-axis parallel structure rigidity, inertia is small, can promote sorting speed to 5 / second (speed promotion 150%), and parallel structure has no cumulative error, and repeat positioning accuracy can reach ±0.2mm (precision promotion 650%), and through vision identification+mechanical arm cooperation realizes multistage sorting, can complete size / defect / shape three dimensions grading simultaneously.

Description

Technical Field

[0001] This utility model belongs to the field of sorting equipment technology, and in particular relates to a three-axis parallel robotic arm. Background Technology

[0002] In high-end potato sorting, potatoes are typically picked up by grippers and sent to other production lines to complete sorting work based on size, quality, etc.

[0003] The main existing technical solutions are as follows: (1) Separation system of conveyor belt + pneumatic push rod: After visually identifying the target position, the pneumatic push rod pushes the defective products away from the conveyor belt.

[0004] The disadvantages are that the sorting process is rough and can easily cause damage to the surface of fruits and vegetables (the rate of abrasion on potato skin is >15%). At the same time, it can only achieve binary sorting of "qualified / unqualified" and cannot be graded and stored according to size and quality. Furthermore, the positioning accuracy is low (error >5mm), and the rate of missed detection of small-sized potatoes is as high as 20%.

[0005] Serial six-axis robotic arm + gripper system: This system uses a multi-joint robotic arm in conjunction with a gripping end effector for grasping and sorting. Disadvantages include high motion inertia, limited sorting speed (≤2 pieces / second), making it difficult to meet the demands of high-speed production lines. Furthermore, the cumulative error of the multi-joint structure leads to decreased positioning accuracy (end-effector repeatability error ±1.5mm), high system cost (>$50,000), and high maintenance complexity.

[0006] Based on this, this application proposes a three-axis parallel robotic arm. Utility Model Content

[0007] The purpose of this utility model embodiment is to provide a three-axis parallel robotic arm, which aims to solve the technical problems existing in the prior art mentioned in the background art.

[0008] This utility model embodiment is implemented as follows: a three-axis parallel robotic arm includes a mounting base and three motors arranged at equal angles on the mounting base. Each motor has a main arm fixedly connected to its output end. Each main arm is connected to a corresponding set of auxiliary arms through a first joint. The three sets of auxiliary arms are connected to the same actuator mounting platform through a second joint. The actuator mounting platform is used to install actuators.

[0009] As a preferred embodiment of this utility model, each set of auxiliary arms includes two connecting rods.

[0010] As another preferred embodiment of this utility model: the first joint includes a shaft, which is fixedly connected to the end of the main arm, and the two ends of the shaft are provided with ball heads that cooperate with two connecting rods. The second joint has the same structure as the first joint.

[0011] As another preferred embodiment of this utility model, the two connecting rods are further fixedly connected by several crossbars.

[0012] As another preferred embodiment of this utility model: the end of the main arm is provided with a through hole, the shaft is installed in the through hole, and the end of the main arm is provided with a locking screw to fix the shaft.

[0013] The beneficial effects of this utility model embodiment are as follows: the three-axis robotic arm has higher rigidity and lower inertia compared to the six-axis parallel structure, which can increase the sorting speed to 5 pieces / second (speed increase of 150%). Moreover, the parallel structure has no cumulative error, and the repeatability positioning accuracy can reach ±0.2mm (accuracy increase of 650%). Furthermore, multi-level sorting can be achieved through visual recognition and robotic arm collaboration, and the three-dimensional classification of size, defects, and shape can be completed simultaneously. In addition, the technical solution of this utility model adopts simple standard pneumatic components and a simplified kinematic chain, which has a simple structure and can greatly reduce costs. Attached Figure Description

[0014] Figure 1 A schematic diagram of the structure of a three-axis parallel robotic arm provided in an embodiment of this utility model; Figure 2 This is a structural schematic diagram of a three-axis parallel robotic arm from another perspective, provided as an embodiment of the present invention.

[0015] In the diagram: 1-Installation base, 2-Motor, 3-Main boom, 4-First joint, 5-Second boom, 6-Second joint, 7-Actuator mounting platform. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model 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 merely illustrative of the present utility model and are not intended to limit the present utility model.

[0017] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various elements, but unless otherwise stated, these elements are not limited by these terms. These terms are used only to distinguish one element from another.

[0018] like Figures 1-2As shown, in one embodiment, a three-axis parallel robotic arm is proposed, including a mounting base 1 and three motors 2 arranged at equal angles on the mounting base 1. A main arm 3 is fixedly connected to the output end of each motor 2. Each main arm 3 is connected to a corresponding set of auxiliary arms 5 through a first joint 4. The three sets of auxiliary arms 5 are connected to the same actuator mounting platform 7 through a second joint 6. The actuator mounting platform 7 is used to install actuators.

[0019] In this embodiment of the utility model, the three motors 2 need to be started and stopped simultaneously. In actual application, the three motors 2 are powered on and started at the same time, driving the three main arms 3 to rotate synchronously. Under the action of the auxiliary arm 5, the first joint 4 and the second joint 6, the actuator mounting platform 7 will move in a straight line along the central axis of the triangle formed by the three motors 2. Similarly, when the three motors 2 rotate in opposite directions, the actuator mounting platform 7 will move in the opposite direction.

[0020] In a preferred embodiment of this utility model, the actuator mounting platform 7 is used to install the actuator, which can be a combination of a cylinder and a suction cup. The cylinder is connected to an external air source through an electromagnetic reversing valve, and a suction cup is installed at the output end of the cylinder. The suction cup is used to pick up and put down materials. The suction cup is connected to an external air source. Mainly, when the external visual recognition system outputs a sorting signal after visual recognition, the three motors 2 start simultaneously, causing the actuator to move to a set position to grab the potato. Then, the three motors 2 rotate synchronously in opposite directions to move the potato to the designated area for placement.

[0021] like Figure 1 As shown, in a preferred embodiment of the present invention, each set of auxiliary arms 5 includes two connecting rods, and the two connecting rods are fixedly connected by several crossbars.

[0022] In this embodiment of the utility model, the auxiliary arm 5 is composed of two connecting rods. In addition, the two connecting rods are fixedly connected by several crossbars to ensure connection rigidity and synchronous movement.

[0023] like Figure 1 As shown, in another preferred embodiment of this utility model, the first joint 4 includes a shaft, which is fixedly connected to the end of the main arm 3. Both ends of the shaft are provided with ball heads that mate with two connecting rods. The second joint 6 has the same structure as the first joint 4. A through hole is provided at the end of the main arm 3, and the shaft is installed in the through hole. A locking screw is provided at the end of the main arm 3 to fix the shaft. In this embodiment of the invention, the hinged connection between the main arm 3 and the auxiliary arm 5 is mainly achieved through ball joint engagement.

[0024] In this embodiment of the invention, the three-axis robotic arm has higher rigidity and lower inertia compared to the six-axis parallel structure, which can increase the sorting speed to 5 pieces / second (a 150% increase in speed). Moreover, the parallel structure has no cumulative error, and the repeatability positioning accuracy can reach ±0.2mm (a 650% increase in accuracy). Furthermore, it uses a vacuum suction cup to adaptively wrap and grasp the potatoes, reducing the damage rate to the potato skin. It also achieves multi-level sorting through visual recognition and robotic arm collaboration, and can simultaneously complete the grading of size, defects, and shape. In addition, the technical solution of this invention uses simple standard pneumatic components and a simplified kinematic chain, resulting in a simple structure and significantly reducing costs.

[0025] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0026] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

[0027] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A three-axis parallel robotic arm, characterized in that, It includes an installation base (1) and three motors (2) arranged at equal angles on the installation base (1). Each motor (2) has a main arm (3) fixedly connected to its output end. Each main arm (3) is connected to a corresponding set of auxiliary arms (5) through a first joint (4). The three sets of auxiliary arms (5) are connected to the same actuator mounting table (7) through a second joint (6). The actuator mounting table (7) is used to install actuators.

2. The three-axis parallel robotic arm according to claim 1, characterized in that, Each of the auxiliary arms (5) in each group contains two connecting rods.

3. The three-axis parallel robotic arm according to claim 2, characterized in that, The first joint (4) includes a shaft, which is fixedly connected to the end of the main arm (3). The two ends of the shaft are provided with ball heads that cooperate with the two connecting rods. The second joint (6) has the same structure as the first joint (4).

4. The three-axis parallel robotic arm according to claim 2, characterized in that, The two connecting rods are also fixedly connected by several crossbars.

5. The three-axis parallel robotic arm according to claim 3, characterized in that, The end of the main arm (3) is provided with a through hole, the shaft is installed in the through hole, and the end of the main arm (3) is provided with a locking screw to fix the shaft.

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