A flexible method for robot module insertion

Abstract

The present invention discloses a flexible method for robot module insertion, which is used to insert a module into a slot by a robot and includes an insertion process of inserting the module to a predetermined depth in the slot position. The insertion process includes an insertion teaching process and an insertion working process. The insertion teaching process is to first use the robot to drive the camera to take a photo of the slot position once, identify the position and angle of the slot in the camera coordinate system at this time, record it as, and record the position and posture of the robot in the base coordinate system at this time, record it as, and then use manual teaching to drive the end effector of the robot to hold the workpiece and insert it into the slot position, and record the position and posture of the robot as. The insertion working process is to first move the robot above the slot position so that the slot position enters the camera's field of view, identify the position and angle of the slot in the camera coordinate system at this time, record it as, and record the position and posture of the robot at this time, record it as, and calculate the deviation of the slot position at this time from the slot position during teaching in the camera coordinate system, and then move the robot to the position and posture to obtain Δ<subgt;slot< / subgt; and θ<subgt;slot< / subgt>. After that, if it is less than the predetermined range, repeat the insertion working process until Δ<subgt;slot< / subgt> and θ<subgt;slot< / subgt> are less than the predetermined range, record the position and posture of the robot at this time, record it as, and move the robot to the insertion position and posture to start the insertion.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of industrial robot applications, and particularly to a flexible method for robot module insertion and installation. Background Art

[0002] Robots have great advantages compared with human labor in large-scale industrial production. However, traditional industrial robots are mostly used in structured scenarios. Ideally, the workpieces should be fully positioned, and the assembly success rate is poor when the degrees of freedom of the workpieces are uncontrollable.

[0003] The flexible assembly method of robots emerged to solve this problem, enabling the assembly or processing of workpieces in different states, breaking through the structural limitations, expanding the application scope of robots, and greatly promoting the progress of intelligent manufacturing technology.

[0004] Therefore, there is an urgent need to propose a flexible method for robot module insertion and installation for high-degree-of-freedom workpieces to adapt to the states in the uncontrollable degrees of freedom directions of the workpieces and achieve insertion and installation assembly. Summary of the Invention

[0005] To achieve the above object, the present invention proposes a flexible method for robot module insertion and installation for high-degree-of-freedom workpieces, which can adapt to the states in the uncontrollable degrees of freedom directions of the workpieces and achieve insertion and installation assembly.

[0006] The present invention is realized through the following technical solutions:

[0007] A flexible method for robot module insertion and installation, used to insert a module into a slot by a robot, including an insertion process of inserting the module to a predetermined depth in the slot position. The insertion process includes an insertion teaching process and an insertion working process. The insertion teaching process is to first use the robot to drive a camera to take a photo of the slot position, identify the position and angle of the slot position in the camera coordinate system at this time, and record them as and , record the position and posture of the robot in the base coordinate system at this time, and record them as and ; then use manual teaching to drive the end effector of the robot to clamp the workpiece and insert it into the slot position, and record the position and posture of the robot as and ; the insertion working process is to first move the robot above the slot position to make the slot position enter the camera's field of view, identify the position and angle of the slot position in the camera coordinate system at this time, and record them as and , record the position and posture of the robot at this time, and record them as and , calculate the deviation of the slot position at this time from the slot position during teaching in the camera coordinate system , , and then move the robot to the position and pose to obtain and After that, if it is less than the predetermined range, repeat the insertion process until and are less than the predetermined range, record the position and pose of the robot at this time, and record them as and , move the robot to the insertion position and pose 、 and start inserting.

[0008] Further, the robot monitors the insertion pressure during the module insertion process. When the insertion pressure exceeds the limit, the end effector jitters a predetermined distance in each of the four directions of left, right, front, and back for three cycles to adapt to the free state of the slider, and then continues to try to insert downward. If the component is successfully inserted downward to the predetermined depth, the insertion ends. If the pressure value exceeds the limit again during the process, the robot drives the end effector to move upward to pull out the component, repeats the insertion process, and if the attempt fails 3 times, skips this slot, assembles the next slot, and records the failed slot.

[0009] Further, the method for positioning the slot during the insertion process is as follows: First, purify the photo information through morphological processing, then identify the rough positioning of the electrical connector through template matching, and then determine the positions of the two pin holes in the picture. Use the positions of the pin holes obtained by rough positioning to define the ROI area, accurately position the centers of the pin holes by identifying the circular contours of the pin hole boundaries, take the midpoint of the line connecting the centers of the two pin holes, and record it as The angle of the connection line is recorded as .

[0010] Further, the calculation method for the pixel accuracy under the change of the camera shooting height during the insertion process is that the number of pixel points identifying the diameter of the high-precision pin hole is d, and its actual processing size is pre-recorded as D, then the pixel accuracy .

[0011] Further, it also includes a pressing process of pressing the module until the upper surface of the module is flush with the upper surface of the side plate: When the pressing device presses the module and the side plate to be flush, the pressing metal block on the pressing device conducts with the side plate, and the flattening signal can be detected, otherwise it is not pressed tightly. ]>

[0012] Further, it also includes a locking process of locking the slider. The locking process includes a locking teaching process and a locking working process. The locking teaching process is to first use the robot to drive the camera to take a photo of the slider once, identify the position of the nut on the slider in the camera coordinate system at this time, and record it as , record the position and pose of the robot in the base coordinate system at this time, and record it as , then use manual teaching to drive the electric screwdriver through the robot to identify the nut and lock the slider, and record the robot position as ; In the locking process, the robot first moves to the position of the screw, places the screw within the camera's field of view, takes a photo, identifies the position of the nut in the camera coordinate system at this time, and records it as , records the robot position at this time, and records it as , calculates the deviation of the nut at this time from the nut during teaching in the camera coordinate system , and then moves the robot to the position ; After obtaining , if it is less than the predetermined range, record the robot position and posture at this time, and record them as and , move the robot to the screw locking position and start locking the slider.

[0013] Further, the method of positioning the screw during the locking process is as follows: first, purify the photo information through morphological processing, then identify the rough positioning of the nut through template matching, and then determine the position of the screw in the picture. Use the position of the roughly positioned screw to define the ROI area, and accurately position the center of the nut by identifying the circular contour of the nut, denoted as .

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The present invention provides a flexible method for robot module insertion, which solves the problem of how to use a robot to achieve high-degree-of-freedom workpiece insertion, and at the same time solves the problems of how to accurately position the workpiece insertion position and adapt to the variable height of camera shooting, and can adapt to the state of the workpiece in the uncontrollable degree-of-freedom direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is the front view of the module;

[0017] Figure 2 is the top view of the module;

[0018] Figure 3 is the front view of the groove;

[0019] Figure 4 is the top view of the groove;

[0020] Figure 5 is the schematic diagram of the pressing process;

[0021] Figure 6 is the schematic diagram of the whole process;

[0022] Wherein: 1. Module; 1-1. Pin; 1-2. First electrical connector; 1-3. Module guide groove; 2. Groove; 2-1. Base; 2-2. Slide block; 2-3. Side plate; 2-4. Pin hole; 2-5. Second electrical connector; 3. Pressing device; 3-1. Pressing metal block. Detailed implementation manners

[0023] The following further describes the preferred mechanisms and methods for realizing the movement of the present invention in conjunction with the accompanying drawings and detailed implementation manners.

[0024] A flexible method for inserting a robot module is targeted at inserting module 1 from top to bottom into the corresponding groove 2 by using a robot.

[0025] As Figure 1-2 shown, the module 1 is a rectangular module, with two pins 1-1 and a first electrical connector 1-2 provided at its bottom, and module guide grooves 1-3 provided on both sides thereof.

[0026] As Figure 3-4 shown, the groove 2 is composed of a base 2-1, a slide block 2-2 and a side plate 2-3 made of metal. There are two high-precision pin holes 2-3 and a second electrical connector 2-4 at the bottom of the groove, which are matched with the bottom of the module. The second electrical connector 2-4 is trapezoidal.

[0027] For the robot pressing module, the slide block 2-2 is inserted into the module guide groove 1-3. After the upper surface of the module is flush with the upper surface of the side plate, it can ensure reliable connection between the first electrical connector 1-2 of the module and the second electrical connector 2-4 of the groove, and between the pin 1-1 of the module 1 and the pin hole 2-3 of the groove.

[0028] After the module is inserted, tightening the screw on the slide block 2-2 can make the slide block slide towards the side plate to lock the module. The slide block is an active component before locking and can sway in six degrees of freedom directions.

[0029] The assembly process of this flexible method for inserting a robot module includes three steps:

[0030] Step 1. The insertion process of inserting the module into the groove to a predetermined depth;

[0031] Step 2. The pressing process of pressing the module until the upper surface of the module is flush with the upper surface of the side plate;

[0032] Step 3. The locking process of locking the slide block.

[0033] In this embodiment, a robot is required to insert the module into the corresponding groove. The robot is fixed, but the position of the groove is variable.

[0034] The end effector of the robot is equipped with a camera, a gripper device for clamping the module and capable of measuring the insertion pressure, a pressing device 3 for flattening the upper surface of the module and the upper surface of the side plate, and an electric screwdriver for locking the slider. The camera coordinate system is denoted as , and at the same time, the robot base coordinate system is denoted as .

[0035] The insertion process of Step 1 in this embodiment is realized in two steps: an insertion teaching process and an insertion working process.

[0036] In the insertion teaching process of the insertion process, first, the robot is used to drive the camera to take a photo of the slot once, identify the position and angle of the slot in the camera coordinate system at this time, and record them as and , record the position and pose of the robot in the base coordinate system at this time, and record them as and , then use manual teaching to drive the end effector of the robot to clamp the workpiece and insert it into the slot through the robot, and record the robot position and pose as and .

[0037] The method for positioning the slot in the photo is as follows: first, purify the photo information through morphological processing, then identify the rough positioning of the electrical connector through template matching, and then roughly determine the positions of the two pin holes in the picture. Use the positions of the roughly located pin holes to define the ROI area, accurately locate the center of the pin hole by identifying the circular contour of the pin hole boundary, take the midpoint of the line connecting the centers of the two pin holes, and denote it as , and denote the connection angle as .

[0038] In this embodiment, the camera calibration can use but is not limited to the nine-point method calibration. Calibrate the coordinate axis directions of the camera coordinate system and the base coordinate system to be consistent, but the pixel accuracy of the camera coordinate system in the insertion process does not have to be fixed, and the shooting height can vary.

[0039] The pixel accuracy of the camera shooting height change in the insertion process of this embodiment is calculated as follows: the number of pixel points of the diameter of the pin hole with high precision identified is d, and its actual processing size is pre-recorded as D, then the pixel accuracy .

[0040] In the insertion working process of the insertion process, the robot first moves to the approximate position of the slot, just place the slot within the camera's field of view, take a photo, identify the position and angle of the slot in the camera coordinate system at this time, and record them as and , record the robot position and pose at this time, and record them as and , calculate the deviation of the slot position at this time from the slot position during teaching in the camera coordinate system , , and then move the robot to the position , attitude .

[0041] Obtain and . After that, if it is less than the predetermined range, repeat the insertion working process in the insertion stage until and are less than the predetermined range. At this time, move the robot to the insertion position and attitude , and start inserting.

[0042] After the insertion process starts, since the position of the slider is free, the module may hit the slider or get stuck and cannot go deeper during the insertion process. The robot needs to monitor the insertion pressure during the module insertion process. When the insertion pressure exceeds the limit, the end effector shakes a predetermined distance in each of the four directions of left, right, front, and back for three cycles to adapt to the free state of the slider, and then continues to try to insert downward.

[0043] If the component is successfully inserted downward to the predetermined depth, the insertion ends. If the pressure value exceeds the limit again during the process, the robot drives the end effector to move upward to pull out the component and repeats the working process steps of the insertion stage. If the attempt fails three times, skip this slot, assemble the next slot, and record the failed slot.

[0044] In this embodiment, chamfers should be designed at the opening positions of the module guide grooves 1-3, the side plates in the grooves, and the guide grooves formed by the sliders on the module to facilitate the robot insertion and increase the allowable positioning error.

[0045] For the slots where the insertion process is successful, enter the pressing process in Step 2: The pressing device 3 of the robot end effector is a plane that can press the module and the base to be flush, and a pressing metal block 3-1 is used at the part contacting the base and connected with a signal, which can be used to detect whether it is pressed flat. When the pressing device 3 presses the module and the side plate to be flush, the pressing metal block 3-1 is conducted with the side plate 2-3, and the pressed-flat signal can be detected, otherwise it is not pressed tightly.

[0046] For the slots where the pressing process is successful, enter the locking process in Step 3. The locking process of the present invention is divided into two steps: the locking teaching process and the locking working process.

[0047] In the locking teaching process of the locking process, first use the robot to drive the camera to take a photo of the slider once, identify the position of the nut on the slider in the camera coordinate system at this time, record it as , record the position and attitude of the robot in the base coordinate system at this time, record it as , and then use manual teaching to drive the electric screwdriver through the robot to recognize the nut and lock the slider, and record the robot position as .

[0048] The method for locating the screw in the photo in this embodiment is as follows: First, purify the photo information through morphological processing, then identify the rough position of the nut through template matching, and then roughly determine the position of the screw in the picture. Use the position of the roughly located screw to define the ROI area, and accurately locate the center of the nut by identifying the circular contour of the nut, denoted as .

[0049] During the locking process of the locking operation, the robot first moves to the approximate position of the screw, places the screw within the camera's field of view, takes a photo, identifies the position of the nut in the camera coordinate system at this time, and records it as . Record the position of the robot at this time, and record it as , calculate the deviation of the nut at this time from the nut during teaching in the camera coordinate system , and then move the robot to the position .

[0050] After obtaining , if it is less than the predetermined range, repeat the working process of the locking process until is less than the predetermined range. At this time, move the robot to the screw locking position and start locking the slider, and the assembly process is completed.

[0051] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. However, any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A flexible method for inserting a module into a slot by a robot, characterized in that: The process includes inserting the module into the slot to a predetermined depth. The insertion process includes the insertion teaching process and the insertion working process. The insertion teaching process is to first use the robot to drive the camera to take a photo of the slot, identify the position and angle of the slot in the camera coordinate system at this time, and record it as and , record the position and posture of the robot in the base coordinate system at this time, and record it as and ; Then use manual teaching to drive the robot to drive the end effector to clamp the workpiece and insert it into the slot, and record the robot position and posture as and The insertion process is to first move the robot to the slot so that the slot enters the camera field of view, identify the position and angle of the slot in the camera coordinate system at this time, and record it as and , record the robot's position and posture at this time, and record it as and Calculate the deviation between the slot position at this time and the slot position during teaching in the camera coordinate system 、 , and then move the robot to the position ,attitude ,get and If the value is less than the preset range, the insertion process is repeated until and If the robot position and posture are smaller than the preset range, the robot position and posture are recorded as and , move the robot to the insertion position and posture 、 Start inserting; The robot monitors the insertion pressure during module insertion. When the insertion pressure exceeds the limit, it shakes the end effector in the four directions of left, right, front and back for three cycles to adjust to the free state of the slider, and then continues to try to insert the component downward. If the component is successfully inserted to the predetermined depth, the insertion is completed. If the pressure value exceeds the limit again during the process, the robot drives the end effector to move upward to pull out the component and repeat the insertion process. If the attempt fails after three times, the slot is skipped and the next slot is assembled, and the failed slot is recorded. The process also includes pressing the module until the upper surface of the module is flush with the upper surface of the side plate: when the pressing device presses the module and the side plate to be flush, the pressing metal block on the pressing device is connected to the side plate, and a flattening signal can be detected, otherwise it is not pressed; The locking process of the slider is also included. The locking process includes a locking teaching process and a locking working process. The locking teaching process is to first use the robot to drive the camera to take a picture of the slider, identify the position of the nut on the slider in the camera coordinate system at this time, and record it as , record the position and posture of the robot in the base coordinate system at this time, and record it as , and then use manual teaching to drive the robot to identify the nut and lock the slider, and record the robot position as The locking process is as follows: the robot first moves to the position of the screw, places the screw in the camera field of view, takes a photo, identifies the position of the nut in the camera coordinate system at this time, and records it as , record the robot position at this time, record as Calculate the deviation between the nut at this time and the nut during teaching in the camera coordinate system , and then move the robot to the position ;get If it is less than the preset range, record the robot’s position and posture at this time and record it as and , move the robot to the screw locking position Start tightening the slide.

2. The flexible method for inserting robot modules according to claim 1, characterized in that: The method for locating the slot during the insertion process is as follows: two pins are provided at the bottom of the module, and two pin holes are provided at the bottom of the slot that match the bottom of the module. The photo information is first purified by morphological processing, and then the rough positioning of the electrical connector is identified by template matching, thereby determining the positions of the two pin holes in the image. The roughly located pin hole positions are used to delineate the ROI area, and the center of the pin hole is precisely located by identifying the circular outline of the pin hole boundary. The midpoint of the line connecting the two pin hole centers is taken as , the connecting angle is recorded as .

3. The flexible method for inserting robot modules according to claim 2, characterized in that: The pixel accuracy of the camera under the change of height during the insertion process The calculation method is as follows: the number of pixels for identifying the pin hole diameter with high precision is d, and the actual processing size is pre-recorded as D, then the pixel accuracy .

4. The flexible method for inserting robot modules according to claim 1, characterized in that: The method for positioning the screw during the locking process is to first purify the photo information through morphological processing, then identify the rough location of the nut through template matching, and then determine the position of the screw in the image, use the rough location of the screw position to delineate the ROI area, and accurately locate the center of the nut by identifying the circular contour of the nut, which is recorded as .

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