An automatically positioned calibrated industrial robot gripping device

Abstract

The utility model discloses an industrial robot grabbing device of automatic positioning calibration, include: mechanical arm, grab mechanism, visual positioning component, displacement compensation mechanism and control box, and grab mechanism sets up in the mechanical arm end, and visual positioning component includes at least two industry cameras, and industry camera is symmetrically distributed in the outer periphery side of grab mechanism. Compared with prior art, through setting up multiple symmetric distribution industry camera and forming visual positioning component, utilize multi -purpose stereo vision principle accurate acquisition workpiece's three -dimensional position and attitude information, realize three -dimensional positioning, through setting up displacement compensation mechanism between the mechanical arm end and grab mechanism, can realize the quick accurate adjustment of grab mechanism in three -dimensional space, compared with prior art through adjusting the whole mechanical arm and correct the position mode, has the advantage that response speed is fast, and adjustment precision is high.

Description

Technical Field

[0001] This utility model relates to the field of industrial robot technology, and in particular to an industrial robot gripping device with automatic positioning and calibration. Background Technology

[0002] In modern industrial production, industrial robots are widely used in automated production lines for tasks such as material handling, transport, and assembly. Existing industrial robot gripping devices typically require pre-setting the workpiece's position parameters to accurately complete the gripping action. However, in actual production processes, due to factors such as workpiece placement deviations, conveyor belt vibrations, and tooling fixture positioning errors, the actual position of the workpiece often deviates from the preset position, leading to gripping failures or workpiece damage.

[0003] Meanwhile, existing robotic gripping devices lack effective displacement compensation mechanisms, and usually require adjusting the gripping position by controlling the movement of the entire robotic arm. This not only results in slow response speed but also low adjustment accuracy, making it difficult to meet the needs of high-precision production. Utility Model Content

[0004] The main purpose of this invention is to provide an industrial robot gripping device with automatic positioning and calibration, which can effectively solve the problems in the background technology.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is: an industrial robot gripping device for automatic positioning and calibration, comprising:

[0006] Robotic arm, and gripping mechanism located at the end of the robotic arm;

[0007] It also includes a visual positioning component, a displacement compensation mechanism, and a control box;

[0008] The visual positioning component includes at least two industrial cameras, which are symmetrically distributed on the outer periphery of the gripping mechanism.

[0009] The displacement compensation mechanism is located between the end of the robotic arm and the gripping mechanism, and is used to adjust the translation and rotation of the gripping mechanism in three-dimensional space.

[0010] The control box is fixedly mounted on the robotic arm. The control box contains a control system, which is electrically connected to the vision positioning component, the displacement compensation mechanism, and the robotic arm. The control system is used to control the displacement compensation mechanism to perform positioning calibration based on the workpiece position information obtained by the vision positioning component.

[0011] As a further description of the above technical solution, the displacement compensation mechanism includes an X-axis translation component, a Y-axis translation component, a Z-axis translation component, and a rotation adjustment component connected in sequence. The X-axis translation component, the Y-axis translation component, and the Z-axis translation component are each composed of a ball screw mechanism driven by a servo motor. The rotation adjustment component includes a drive motor and a harmonic reducer.

[0012] As a further description of the above technical solution, the X-axis translation component, the Y-axis translation component and the Z-axis translation component are all equipped with grating ruler displacement sensors, and the rotation adjustment component is equipped with an angle encoder. The grating ruler displacement sensors and the angle encoder are both electrically connected to the control system.

[0013] As a further description of the above technical solution, the gripping mechanism includes a base fixedly mounted on the output end of the rotary adjustment component. A gripping motor is installed at the center of the lower inner wall of the base. A guide groove is provided on the lower outer wall of the base. Two symmetrically distributed gripping fingers are slidably arranged in the guide groove. The output shaft of the gripping motor passes through the base and is fixedly connected to a strip-shaped rotating plate. Both ends of the strip-shaped rotating plate are rotatably connected to pull plates. The other end of the pull plates is rotatably connected to the gripping fingers.

[0014] As a further description of the above technical solution, pressure sensors are provided on the side walls of the two grasping fingers that are close to each other, and the pressure sensors are electrically connected to the control system.

[0015] As a further description of the above technical solution, flexible contact pads are provided on the sidewalls of the two grasping fingers that are close to each other, and the surface of the flexible contact pads is provided with anti-slip textures.

[0016] As a further description of the above technical solution, the control system includes an industrial controller and a binocular vision processing unit, wherein the industrial controller is electrically connected to the binocular vision processing unit.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. By setting up a vision positioning component consisting of multiple symmetrically distributed industrial cameras, the three-dimensional position and orientation information of the workpiece can be accurately obtained using the principle of multi-view stereo vision, thereby achieving three-dimensional positioning.

[0019] 2. By setting a displacement compensation mechanism between the end of the robotic arm and the gripping mechanism, the gripping mechanism can be quickly and accurately adjusted in three-dimensional space. Compared with the existing technology of correcting the position by adjusting the entire robotic arm, it has the advantages of fast response speed and high adjustment accuracy. Attached Figure Description

[0020] Figure 1This is a schematic diagram of the overall structure of an industrial robot gripping device for automatic positioning and calibration according to this utility model.

[0021] Figure 2 This is a schematic diagram of the displacement compensation mechanism of an industrial robot gripping device with automatic positioning and calibration according to the present invention.

[0022] Figure 3 This is a schematic diagram of the gripping mechanism of an industrial robot gripping device with automatic positioning and calibration according to the present invention.

[0023] Figure 4 This is a schematic diagram of the base structure of an industrial robot gripping device for automatic positioning and calibration according to this utility model.

[0024] In the diagram: 1. Robotic arm; 2. Gripping mechanism; 3. Vision positioning component; 4. Displacement compensation mechanism; 5. Control box; 31. Industrial camera; 41. X-axis translation component; 42. Y-axis translation component; 43. Z-axis translation component; 44. Rotation adjustment component; 6. Grating ruler displacement sensor; 21. Base; 22. Gripping motor; 23. Guide groove; 24. Gripping finger; 25. Strip plate; 26. Pull plate; 241. Pressure sensor; 242. Flexible contact pad. Detailed Implementation

[0025] To make the technical means, creative features, and objectives of this utility model easier to understand, the following describes this utility model in conjunction with specific embodiments.

[0026] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," and "connected," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0028] Please see Figure 1-4 This invention provides an industrial robot gripping device for automatic positioning and calibration, comprising a robotic arm 1, a gripping mechanism 2, a vision positioning component 3, a displacement compensation mechanism 4, and a control box 5. The robotic arm 1 is the basic supporting component, driving the gripping mechanism 2 and the vision positioning component 3 to achieve a wide range of movement, providing the initial position basis for the gripping action. The gripping mechanism 2 directly contacts the workpiece to complete the gripping and releasing actions. The vision positioning component 3 uses at least two symmetrically distributed industrial cameras 31 to acquire workpiece images from different angles, avoiding positioning errors caused by blind spots of a single camera's viewpoint, and providing accurate position data for subsequent calibration. The preferred model of the industrial camera 31 is the Basler ACA2500-14UC. The displacement compensation mechanism 4 connects the end of the robotic arm 1 to the gripping mechanism 2, compensating for the insufficient accuracy of the robotic arm 1 during wide-range movement, and achieving small-range, high-precision three-dimensional translation and rotation adjustment. The control system in the control box 5 acts as the central hub, integrating vision positioning data and driving the displacement compensation mechanism 4 to form a closed-loop control of perception, decision-making, and execution, ensuring real-time calibration of the gripping position.

[0029] To further explain, the visual positioning component 3 operates based on the principle of binocular stereo vision. Specifically, before use, two symmetrically distributed industrial cameras 31 need to be calibrated. The intrinsic and extrinsic parameters of the cameras are obtained by photographing a pre-set checkerboard calibration board, and the calibration parameters are pre-stored in the binocular vision processing unit for subsequent image distortion correction and 3D coordinate calculation. Before grasping, the two industrial cameras 31 simultaneously acquire images of the area to be grasped, and the image data is transmitted to the binocular vision processing unit via Ethernet. The processing unit first uses a Gaussian filtering algorithm to remove image noise, and then, based on the pre-stored camera intrinsic parameters, performs radial and tangential distortion correction on the image to eliminate the influence of lens optical errors on positioning. Key feature points such as workpiece edges and positioning holes are extracted using the Canny edge detection algorithm, and then the FLANN matcher is used to match feature points in the images from the two cameras, selecting highly similar corresponding feature point pairs to ensure the accuracy of subsequent disparity calculation. Based on the matched feature point pairs, a semi-global block matching algorithm is used to calculate the disparity of the feature points in the two images. By combining pre-stored camera baseline distance and focal length, and using the principle of triangulation, the three-dimensional coordinates of the workpiece are generated. Simultaneously, through attitude vector analysis of feature points, the tilt, rotation, and other attitude information of the workpiece are determined. Finally, the three-dimensional coordinates and attitude data are transmitted to the industrial controller.

[0030] To further explain, the displacement compensation mechanism includes an X-axis translation component 41, a Y-axis translation component 42, a Z-axis translation component 43, and a rotation adjustment component 44 connected in sequence. The X-axis translation component 41, the Y-axis translation component 42, and the Z-axis translation component 43 correspond to the X, Y, and Z directions in three-dimensional space, respectively. The position calibration of the gripping mechanism 2 in any translation direction is achieved through "independent control + combined adjustment". The rotation adjustment component 44 can realize the rotation adjustment of the gripping mechanism 2 from 20 to 360°. The X-axis translation component 41, the Y-axis translation component 42, and the Z-axis translation component 43 are each composed of ball screw mechanisms driven by servo motors. The rotation adjustment component 44 includes a drive motor and a harmonic reducer.

[0031] To further explain, the X-axis translation component 41, the Y-axis translation component 42, and the Z-axis translation component 43 are orthogonally arranged, and the motion guide rails of each component are independent and perpendicular to each other, so as to avoid mechanical interference to other axes when one axis moves.

[0032] To further explain, the X-axis translation assembly 41, the Y-axis translation assembly 42 and the Z-axis translation assembly 43 are all equipped with grating ruler displacement sensors 6, and the rotation adjustment assembly 44 is equipped with an angle encoder. The grating ruler displacement sensors 6 and the angle encoder are all electrically connected to the control system.

[0033] To further explain, the preferred model of the grating ruler displacement sensor 6 is LS486C. It uses optical principles to read the actual displacement of the translation component in real time and can feed the data back to the control system in real time. If there is a deviation between the actual displacement and the target displacement, the control system will immediately drive the servo motor to correct it, ensuring translation accuracy.

[0034] To further explain, the preferred angle encoder model is RVI58N, which can detect the rotation angle in real time. Combined with the high-precision transmission of the harmonic reducer, it can achieve real-time calibration of the rotation angle and avoid posture deviation caused by motor step loss.

[0035] To further explain, the gripping mechanism 2 includes a base 21 fixedly mounted at the output end of the rotary adjustment assembly 44. A gripping motor 22 is installed at the center of the lower inner wall of the base 21. A guide groove 23 is provided on the lower outer wall of the base 21. Two symmetrically distributed gripping fingers 24 are slidably arranged in the guide groove 23. The output shaft of the gripping motor 22 passes through the base 21 and is fixedly connected to a strip-shaped rotating plate 25. Both ends of the strip-shaped rotating plate 25 are rotatably connected to a pull plate 26. The other end of the pull plate 26 is rotatably connected to the gripping fingers 24.

[0036] To further explain, the base 21 serves as the fixed frame of the gripping mechanism 2, with one end connected to the output end of the rotation adjustment assembly 44, and the other end providing mounting support for the gripping motor 22 and the gripping fingers 24. The gripping motor 22 drives the strip-shaped rotating plate 25 to rotate via its output shaft. The pull plates 26 at both ends of the strip-shaped rotating plate 25 convert the rotational motion into the linear motion of the gripping fingers 24. When the strip-shaped rotating plate 25 rotates clockwise, the pull plates 26 pull the two gripping fingers 24 closer together along the guide groove 23, thus gripping the workpiece. When the strip-shaped rotating plate 25 rotates counterclockwise, the pull plates 26 push the gripping fingers 24 away from each other, thus releasing the workpiece. The guide groove 23 limits the direction of movement of the gripping fingers 24, preventing the gripping fingers 24 from deviating and causing misalignment with the workpiece.

[0037] To further explain, each of the two gripping fingers 24 is provided with a pressure sensor 241 on the side wall where they are close to each other. The pressure sensor 241 is electrically connected to the control system. Each of the two gripping fingers 24 is provided with a flexible contact pad 242 on the side wall where they are close to each other. The surface of the flexible contact pad 242 is provided with anti-slip texture.

[0038] To further explain, the pressure sensor 241 is preferably a Keyence AP-40S model, which directly contacts the workpiece surface during workpiece gripping, collecting contact pressure data in real time and transmitting it to the control system. The control system presets a pressure threshold. If the detected pressure exceeds the threshold, the control system immediately controls the gripping motor 22 to reverse, reducing the gripping force. If the pressure is below the threshold, the control system drives the gripping motor 22 to rotate forward, increasing the gripping force to ensure a stable and damage-free gripping process.

[0039] To further explain, the flexible contact pad 242 is made of food-grade silicone rubber, which has good elasticity and chemical stability, preventing chemical reactions or scratches with the workpiece. The anti-slip texture on the surface increases contact friction, preventing the workpiece from slipping during gripping or movement, even when gripping smooth workpieces. At the same time, the cushioning effect of the silicone material reduces the impact force at the moment of gripping, protecting the surface precision of the workpiece.

[0040] To further explain, the control system includes an industrial controller and a binocular vision processing unit. The binocular vision processing unit can perform stereo matching processing on the image information acquired by the industrial camera 31 to generate the three-dimensional coordinates and posture information of the workpiece.

[0041] To further explain, the preferred industrial controller is the Siemens S7-1200, which has multi-channel signal input / output capabilities. It can simultaneously receive image data from the vision positioning component 3, displacement data from the grating ruler displacement sensor 6, and pressure data from the pressure sensor 241, and output control commands according to a preset program to drive the robotic arm 1, displacement compensation mechanism 4, and gripping motor 22 to work together.

[0042] To further explain, the preferred model of the binocular vision processing unit is the Advantech UNO-2484G, which is equipped with a stereo matching algorithm to process the images acquired by the two industrial cameras 31. First, image distortion is corrected by camera calibration parameters, then the coordinates and orientation of the workpiece in three-dimensional space are calculated by feature point matching, and finally the processing results are transmitted to the industrial controller to provide accurate target position data for displacement compensation.

[0043] It should be noted that this utility model is an industrial robot gripping device for automatic positioning and calibration. During use, the device is powered on, and the industrial controller and binocular vision processing unit inside the control box 5 complete a self-test. Parameters are preset through the industrial controller's human-machine interface, including workpiece type parameters such as size, material, and pressure threshold for matching; visual positioning parameters such as the exposure time and gain of the industrial camera 31 to ensure image clarity; and the gripping target position, such as the coordinates of the target platform where the gripped workpiece should be placed. After the parameters are set, the industrial controller sends instructions to the vision positioning component 3, and two symmetrically distributed industrial cameras 31 simultaneously acquire images of the workpiece in the gripping area. The image data is transmitted in real-time to the binocular vision processing unit via Ethernet. The binocular vision processing unit processes the images, first using a Gaussian filtering algorithm to remove noise and correcting lens distortion according to the calibration parameters of the industrial camera 31. Then, it identifies key features of the workpiece, such as edges and positioning holes, to determine the pixel position of the workpiece in the image. The disparity of corresponding feature points in the images of the two industrial cameras 31 is calculated using the SGBM algorithm, and combined with the baseline distance between the cameras, the three-dimensional coordinates and posture information of the workpiece are generated. The binocular vision processing unit transmits the workpiece's three-dimensional coordinates and posture information to the industrial controller. The industrial controller calculates the deviation value and sends control commands to the displacement compensation mechanism 4 based on the deviation value. For translational deviations, the servo motors driving the X-axis translation components 41, Y-axis translation components 42, and Z-axis translation components 43 rotate forward, driving the gripping mechanism 2 to move via a ball screw mechanism. For posture deviations, the drive motor driving the rotation adjustment component 44 rotates in reverse, driving the gripping mechanism 2 to rotate via a harmonic reducer. During adjustment, the grating ruler displacement sensor 6 detects the actual displacement of the X, Y, and Z axes in real time, and the angle encoder detects the rotation angle in real time, feeding the data back to the industrial controller. Calibration is complete when the actual adjustment amount of the displacement compensation mechanism 4 matches the target deviation value. At this point, the center of the gripping mechanism 2 is aligned with the center of the workpiece, and its posture is adapted to the workpiece. The industrial controller sends a gripping command to the gripping motor 22 of the gripping mechanism 2. The output shaft of the gripping motor 22 rotates clockwise, driving the strip plate 25 to rotate. The pull plates 26 at both ends of the strip plate 25 pull the two gripping fingers 24 closer together along the guide groove 23. The flexible contact pads 242 on the inner side of the gripping fingers 24 gradually come into contact with the workpiece surface. The pressure sensor 241 detects the contact pressure in real time and feeds the data back to the industrial controller. When the pressure reaches a preset threshold, the industrial controller immediately sends a stop command, and the gripping motor 22 stops rotating to avoid excessive pressure damaging the workpiece. After gripping, the industrial controller drives the robotic arm 1 to move the gripping mechanism 2 and the workpiece above the target table. During the movement, the displacement compensation mechanism 4 maintains its current state to ensure the stability of the workpiece posture.The robotic arm 1 moves to the preset position on the target table, and the industrial controller sends a release command to the gripping motor 22. The output shaft of the gripping motor 22 rotates counterclockwise, the strip plate 25 rotates counterclockwise, and the pull plate 26 pushes the gripping fingers 24 away from each other along the guide groove 23 until the gripping fingers 24 are completely separated from the workpiece, and the workpiece is placed stably on the target table.

[0044] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. An industrial robot gripping device for automatic positioning and calibration, comprising a robotic arm (1) and a gripping mechanism (2) disposed at the end of the robotic arm (1), characterized in that: It also includes a visual positioning component (3), a displacement compensation mechanism (4), and a control box (5); The visual positioning component (3) includes at least two industrial cameras (31), which are symmetrically distributed on the outer periphery of the gripping mechanism (2); The displacement compensation mechanism (4) is located between the end of the robotic arm (1) and the gripping mechanism (2), and the gripping mechanism (2) can be adjusted by translation and rotation in three-dimensional space; The control box (5) is fixedly mounted on the robotic arm (1). The control box (5) contains a control system. The control system is electrically connected to the visual positioning component (3), the displacement compensation mechanism (4) and the robotic arm (1) respectively. It is used to control the displacement compensation mechanism (4) to perform positioning calibration based on the workpiece position information obtained by the visual positioning component (3).

2. The industrial robot gripping device for automatic positioning and calibration according to claim 1, characterized in that: The displacement compensation mechanism includes an X-axis translation component (41), a Y-axis translation component (42), a Z-axis translation component (43), and a rotation adjustment component (44) connected in sequence. The X-axis translation component (41), the Y-axis translation component (42), and the Z-axis translation component (43) are each composed of a ball screw mechanism driven by a servo motor. The rotation adjustment component (44) includes a drive motor and a harmonic reducer.

3. The industrial robot gripping device for automatic positioning and calibration according to claim 2, characterized in that: The X-axis translation component (41), Y-axis translation component (42) and Z-axis translation component (43) are each equipped with a grating ruler displacement sensor (6), and the rotation adjustment component (44) is equipped with an angle encoder. The grating ruler displacement sensor (6) and the angle encoder are both electrically connected to the control system.

4. The industrial robot gripping device for automatic positioning and calibration according to claim 2, characterized in that: The gripping mechanism (2) includes a base (21) fixedly installed at the output end of the rotary adjustment assembly (44). A gripping motor (22) is installed at the center of the lower inner wall of the base (21). A guide groove (23) is provided on the lower outer wall of the base (21). Two symmetrically distributed gripping fingers (24) are slidably arranged in the guide groove (23). The output shaft of the gripping motor (22) passes through the base (21) and is fixedly connected to a strip rotating plate (25). Both ends of the strip rotating plate (25) are rotatably connected to a pull plate (26). The other end of the pull plate (26) is rotatably connected to the gripping fingers (24).

5. The industrial robot gripping device for automatic positioning and calibration according to claim 4, characterized in that: Pressure sensors (241) are provided on the sidewalls of the two grasping fingers (24) that are close to each other, and the pressure sensors (241) are electrically connected to the control system.

6. The industrial robot gripping device for automatic positioning and calibration according to claim 4, characterized in that: Flexible contact pads (242) are provided on the sidewalls of the two grasping fingers (24) that are close to each other, and the surface of the flexible contact pads (242) is provided with anti-slip texture.

7. The industrial robot gripping device for automatic positioning and calibration according to claim 1, characterized in that: The control system includes an industrial controller and a binocular vision processing unit, which are electrically connected.

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