Automatic control method for grabbing counterweight, mechanical arm and robot

Abstract

The present application belongs to the technical field of weight conveying, and particularly relates to a control method for automatically grabbing a knob weight, a machine arm and a robot. The present application takes the knob body of the knob as a grabbing area, obtains the three-dimensional contour of the weight under the robot coordinates, finds the characteristic mark points of the weight based on the three-dimensional geometric size features of the surface contour of the weight from top to bottom, identifies the knob cap and the weight body of the knob, positions the spatial pose and position of the knob body of the knob weight, then judges the weight grade of the weight by identifying the weight mark pattern of the weight body, and finally grabs the grabbing area by the tentacle on the machine arm. The present application improves the intelligent level, safety and conveying efficiency of grabbing the knob weight.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of weight conveying, and particularly relates to a control method for automatically grabbing a knob weight, a robot arm and a robot. BACKGROUND

[0002] A knob weight is a widely used weight. The knob weight comprises a weight body, a knob connected to the top of the weight body, a knob body and a knob cap. The knob body is connected to the weight body, the knob cap is connected to the top of the knob body, and the diameter of the knob body is smaller than that of the knob cap, so that the knob body forms a concave area relative to the knob cap and the weight body. At present, in different working environments, the knob weight is usually carried by taking the weight body or the knob cap as a gripping area, and most of the carrying is realized by manual or semi-automatic machine, which has low intelligent level and high labor cost. In addition, in the carrying process, friction and collision may occur, which may cause irreparable loss to the high-precision weight. SUMMARY

[0003] The present application provides a control method for automatically grabbing a knob weight, which improves the intelligent level of grabbing the knob weight.

[0004] The present application is realized by the following technical scheme: a control method for automatically grabbing a knob weight, comprising the following steps: taking the knob body of the knob as a grabbing area, identifying the knob cap and the weight body first, then identifying the grabbing area according to the geometric size relationship between the knob cap, the knob body and the weight body, and controlling the tentacle on the robot arm to grab the grabbing area.

[0005] Further, a laser scanner on the robot arm is controlled to perform laser scanning on the knob weight from top to bottom to identify the knob cap and the weight body.

[0006] Further, a three-axis vertical coordinate system is established with the lower end of the robot arm as the origin, and the Y-axis direction is the extension direction of the robot arm; the laser scanning mode is that the laser scanner is controlled to rotate downward from a horizontal line above the knob weight to perform scanning, and the coordinates of a feature point a on the knob cap and a feature point b on the weight body are obtained in sequence. The feature point a is a laser point with the minimum value in the Y-axis direction among the laser points with the maximum value in the Z-axis direction. The feature point b is a laser point with the maximum value in the Z-axis direction among the laser points with the minimum value in the Y-axis direction.

[0007] Further, the coordinates of a feature point c on the knob body are calculated according to the coordinates of the feature point a and the feature point b, according to the following formula:

[0008]

[0009] In the formula, xa This represents the coordinates of feature point a on the X-axis; z a This represents the coordinates of feature point a on the Z-axis; z b R represents the coordinate value of feature point b on the Z-axis; R represents the radius of the button; k1 represents the distance coefficient from feature point a to feature point c in the Y-axis direction, k1>1; k2 represents the distance coefficient from feature point b to feature point c, k2>1.

[0010] Furthermore, k1 = 2, k2 = 2.

[0011] Furthermore, the radius R and distance coefficient k1 of the button are automatically obtained as follows:

[0012] A laser image is generated based on the point cloud data composed of laser dots obtained from scanning the weight. Then, the text information in the laser image is analyzed by an image recognition algorithm to obtain the weight model or weight. Based on the weight model or weight, the weight model-weight size mapping table or the weight-weight size mapping table is consulted to obtain the radius R and distance coefficient k1 of the button.

[0013] Furthermore, a laser image is generated based on the point cloud data composed of laser dots obtained from scanning the weight. Then, the text information in the laser image is analyzed by an image recognition algorithm to obtain the weight of the weight. When it is determined that the tentacle on the robotic arm cannot bear the weight of the weight, a prompt is made to replace the tentacle.

[0014] Furthermore, the tentacle is a two-finger parallel tentacle that opens and closes along the X-axis. The root of the two-finger parallel tentacle in the open state is moved to a position maintaining a safe distance l from the feature point c in the Y-axis direction. At this time, the coordinates of the tentacle root are (x... c ,y c -l,z c ).

[0015] The present invention also provides a robotic arm, including a controller, the controller being configured with a weight-grabbing program for executing the control method for automatically grasping lifting weights as described in the present invention.

[0016] The present invention also provides a robot including a transport chassis, wherein the transport chassis is provided with the robotic arm described in the present invention.

[0017] Compared with the prior art, the beneficial effects of the present invention include:

[0018] 1. This invention addresses the external characteristics of knob-lift weights by first identifying the easily identifiable protruding parts: the knob cap and the weight body; then, based on the geometric dimensional relationship between the knob cap, knob body, and the weight body, identifying the less easily identifiable recessed part: the knob body. This invention uses the knob body as the gripping area. The knob body is relatively small compared to the weight body and knob cap, requiring a smaller reach arm. This allows the robotic arm to flexibly, easily, and accurately grip the weight. Furthermore, because the knob cap is larger than the knob body, it prevents the knob-lift weight from falling from the reach arm, improving the safety of the weight during transport.

[0019] 2. This invention uses laser scanning to identify the button and the main body of the weight, which has the advantages of wide recognition range and high recognition efficiency.

[0020] 3. This invention identifies the button and the weight body by laser scanning to identify feature point a on the button and feature point b on the weight body. It can obtain the spatial coordinates of feature point a and feature point b. Based on the spatial coordinates of feature point a and feature point b and the geometric dimensional relationship between the button, the button body and the weight body, the coordinates of feature point c on the button body are calculated. The algorithm is simple and efficient, improves the button body recognition efficiency, and thus improves the transportation efficiency.

[0021] 4. This invention automatically identifies key parameters of the lifting knob weight using laser images acquired through laser scanning. It is applicable to weights of different specifications, exhibiting adaptability and further improving the level of intelligence. Simultaneously, it eliminates the need for an additional visual recognition module, saving hardware costs.

[0022] 5. This invention uses two parallel fingers as tentacles to easily grip the button body, while also setting a safety distance l to prevent the tentacles from hitting the button body. Attached Figure Description

[0023] Figure 1 A schematic diagram of the principle for automatically grasping weights using lifting knobs;

[0024] Figure 2 This is a schematic diagram of the robot used in this specific embodiment;

[0025] Figure 3 This is a diagram showing the initial pose relationship between the laser scanner and the robotic arm in robot coordinates.

[0026] Figure 4 This is a flowchart illustrating the robot's grasping and transporting of weights in this specific embodiment. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings:

[0028] refer to Figure 1As shown, an automatic gripping control method for lifting weights includes the following steps: using the body of the lifting button as the gripping area, first identifying the button cap and the main body of the weight, then identifying the gripping area based on the geometric dimensional relationship between the button cap, the body of the lifting button and the main body of the weight, and controlling the tentacles on the robotic arm to grip the gripping area.

[0029] Based on the external characteristics of the lever-lift weight, the easily identifiable protruding parts are first identified: the knob cap and the weight body. Then, based on the geometric dimensional relationship between the knob cap, knob body, and weight body, the less easily identifiable recessed parts are identified: the knob body. This invention uses the knob body as the gripping area. The knob body is relatively small compared to the weight body and knob cap, requiring a smaller reach arm. This allows the robotic arm to flexibly, easily, and accurately move the reach arm to grip the weight. Furthermore, because the knob cap is larger than the knob body, it prevents the lever-lift weight from falling off the reach arm, improving the safety of the weight during transportation.

[0030] In this specific embodiment, a laser scanner on the robotic arm, controlled by a controller, scans the lifting weight from top to bottom to identify the knob and the weight body. An infrared scanner or a camera can also be used instead of a laser scanner, but a laser scanner is preferred due to its advantages of a wide recognition range and high recognition efficiency.

[0031] In this specific embodiment, a robotic arm is mounted on a transport chassis and assembled into a robot for transporting and grasping the invention, as described in the reference. Figure 2 As shown, the device includes a transport chassis 1, on which a three-axis robotic arm with X, Y and Z axis movement directions is provided. The X-axis arm 2 of the three-axis robotic arm is fixedly mounted on the transport chassis 1 as a base, and the Z-axis arm 3 serves as a column connecting the X-axis arm 2 and the Y-axis arm 4. Tentacles 9 are installed on the Y-axis arm 4, and the tentacles 9 are two parallel tentacles that open and close along the X-axis direction.

[0032] The three-axis robotic arm is mounted on one side of the transport chassis 1, with the X-axis arm 2 flush with the edge of the transport chassis 1, allowing the tentacle 9 to have the farthest working distance on the Y-axis. A counterweight device 6 is provided on the side of the transport chassis 1 opposite to the three-axis robotic arm, and the device includes, but is not limited to, counterweight blocks.

[0033] The transport chassis 1 is also equipped with a control module 7 and a power module 8. The power module 8 supplies power to various electrical modules on the transport robot. The control module 7 is mainly used to control the movement of the three-axis robotic arm.

[0034] The X-axis arm 2 is equipped with an X-direction slide rail, and the Z-axis arm 3 is slidably connected to the X-direction slide rail via a first slider; the Z-axis arm 3 is equipped with a Z-direction slide rail, and the Y-axis arm 4 is slidably connected to the Z-direction slide rail via a second slider; the Y-axis arm 4 is equipped with a Y-direction slide rail, and the tentacle 9 is connected to the Y-axis arm 4 via a mounting base, and the mounting base is slidably connected to the Y-direction slide rail via a third slider; the first slider, the second slider, and the third slider are each driven by their respective motors.

[0035] A servo motor can be used for driving, with the servo motor connected to the slider via a lead screw and nut. The lead screw and nut convert the rotary motion of the servo motor into linear motion. Alternatively, a linear motor can be used directly for driving.

[0036] The three-axis robotic arm can drive the tentacles to move along the X, Y and Z axes respectively, thereby moving the open tentacles to the lifting button position of the weight 10, so that the button body 1001 is located in the tentacle 9. After the two fingers are parallel to the tentacle and close along the X axis, the lifting button can be clamped and transported.

[0037] A laser scanner 5 is mounted on the upper end of the Z-axis arm 3, and the laser scanner 5 is oriented in the same direction as the tentacle 9. By scanning the weights with the laser scanner, the shape and position information of the weights can be obtained, providing data support for the intelligent control of the movement of the tentacle 9 during the control period.

[0038] refer to Figure 3 As shown in this specific embodiment, a three-axis vertical coordinate system is established with the lower end of the robotic arm as the origin, and the Y-axis direction is the extension and retraction direction of the robotic arm. The initial pose of the laser scanner is a horizontal pose at a height of P1 from the origin. In the initial pose, the laser scanner emits laser light in a horizontal direction. The laser scanner rotates downward by a set angle to scan and confirm the starting position of the tentacle: the distance to the laser scanner should be P2.

[0039] Before each operation, the spatial error is calibrated by the initial pose of the laser scanner: First, the origin of the robot is confirmed by the laser scanner, and then the laser scanner is moved or rotated to judge the error of the laser scanner's posture and physical state. For example, if the rotation is 30 degrees, the actual position is 29.99 degrees, and the error is 0.01 degrees. The tentacles start at an ideal spatial position in the robot coordinate system. The error between the actual position and the ideal position is the correction error. The obtained correction error is used for position compensation.

[0040] refer to Figure 1As shown, the laser scanning method is as follows: the laser scanner is controlled to rotate downwards from the horizontal line above the lifting button weight in the hand position to scan, and the coordinates of feature point a on the button and feature point b on the weight body are obtained in sequence. Feature point a is the laser point with the minimum value in the Y-axis direction identified from the laser points with the maximum value in the Z-axis direction; feature point b is the laser point with the maximum value in the Z-axis direction identified from the laser points with the minimum value in the Y-axis direction.

[0041] In this specific embodiment, the coordinates of feature point c on the button are calculated based on the coordinates of feature point a and feature point b, according to the following formula:

[0042]

[0043] In the formula, x a This represents the coordinates of feature point a on the X-axis; z a This represents the coordinates of feature point a on the Z-axis; z b R represents the coordinate value of feature point b on the Z-axis; R represents the radius of the button; k1 represents the distance coefficient from feature point a to feature point c in the Y-axis direction, k1>1; k2 represents the distance coefficient from feature point b to feature point c, k2>1.

[0044] The distance coefficient k1 represents the distance from feature point a to feature point c. Different specifications or weights of lifting weights have different distance coefficients k1. The lifting weights are configured in advance into the weight model-weight size mapping table or weight-weight size mapping table according to the size design data of the lifting weights.

[0045] The distance coefficient k2 represents the distance from feature point b to feature point c, and determines whether the tentacle grasps the lifting weight closer to the knob or closer to the weight body.

[0046] In this specific embodiment, k1 = 2, k2 = 2. Taking the distance coefficient k1 = 2 indicates that feature point c is located at the midpoint of the button's radius, and feature point a is neither too far nor too close to feature point c. Taking the distance coefficient k2 = 2 indicates that feature point c is located at the midpoint of the line connecting feature point b and feature point a.

[0047] In this specific embodiment, the radius R and distance coefficient k1 of the button are automatically obtained in the following manner:

[0048] A laser image is generated based on the point cloud data composed of laser dots obtained from scanning the weight. Then, the text information in the laser image is analyzed by an image recognition algorithm to obtain the weight model or weight. Based on the weight model or weight, the weight model-weight size mapping table or the weight-weight size mapping table is consulted to obtain the radius R and distance coefficient k1 of the button.

[0049] In this specific embodiment, a laser image is generated based on the point cloud data composed of laser dots obtained by scanning the weight. Then, the text information in the laser image is analyzed by an image recognition algorithm to obtain the weight of the weight. When it is determined that the tentacle on the robotic arm cannot bear the weight of the weight, a prompt is made to replace the tentacle.

[0050] In this specific embodiment, the tentacle is a two-finger parallel tentacle that opens and closes along the X-axis. The root of the two-finger parallel tentacle in the open state is moved to a position that maintains a safe distance l from the feature point c in the Y-axis direction. At this time, the coordinate value of the tentacle root is (x... c ,y c -l,z c ),refer to Figure 1 The position of point d in the middle.

[0051] The present invention also provides a robotic arm, including a controller, the controller being configured with a weight-grabbing program for executing the control method for automatically grasping lifting weights as described in the present invention.

[0052] The present invention also provides a robot including a transport chassis, wherein the transport chassis is provided with the robotic arm described in the present invention.

[0053] refer to Figure 4 As shown, the process of the robot transporting weights includes the following steps:

[0054] First, the robot scans the outline of the weight in its initial pose. Based on the principle of laser ranging, the distance between the laser scanner and the lifting weight can be obtained, which is used as the distance from the robotic arm to the lifting weight. If this distance is greater than the maximum extension distance of the robotic arm ( Figure 1 If L), then control the robot to move along the Y-axis toward the lifting weight until the distance from the robotic arm to the lifting weight is less than the maximum extension distance of the robotic arm.

[0055] Then, the weights are scanned, and the weights are identified and grasped using the automatic grasping and lifting button control method of this specific embodiment.

[0056] Finally, after successful grabbing, control the carrier chassis to move to the designated position to unload the weight.

[0057] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0058] In the description of this invention, unless otherwise stated, the terms "upper," "lower," "left," "right," "inner," "outer," 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 invention 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 invention.

[0059] The above technical solutions are merely specific embodiments of the present invention. For those skilled in the art, based on the principles disclosed in the present invention, it is easy to make various types of improvements or modifications, and not limited to the technical solutions described in the above specific embodiments of the present invention. Therefore, the foregoing descriptions are only preferred and not restrictive.

Claims

1. A control method for automatically grasping lifting knob weights, characterized in that, The process includes the following steps: using the body of the lifting knob as the gripping area, first identify the knob cap and the main body of the weight, then identify the gripping area based on the geometric dimensional relationship between the knob cap, the knob body and the main body of the weight, and control the tentacles on the robotic arm to grip the gripping area. The laser scanner on the robotic arm is controlled to perform laser scanning on the lifting weight from top to bottom to identify the knob and the main body of the weight; A three-axis vertical coordinate system is established with the lower end of the robotic arm as the origin, and the Y-axis direction is the extension and retraction direction of the robotic arm; the laser scanning method is as follows: control the laser scanner to rotate downwards from the horizontal line above the lifting weight to scan and sequentially acquire the feature points on the button. Feature points on the main body of the weight The coordinates of the feature point That is, the laser point with the minimum value in the Y-axis direction identified from the laser points with the maximum value in the Z-axis direction; the feature point That is, the laser point with the maximum value in the Z-axis direction identified from the laser points with the minimum value in the Y-axis direction; Based on feature points With feature points The coordinates of feature point c on the button are calculated using the following formula: In the formula, Representing feature points The coordinates on the X-axis; Representing feature points Coordinate values ​​on the Z-axis; Representing feature points Coordinate values ​​on the Z-axis; Indicates the radius of the button; Indicates the direction from the feature point along the Y-axis. The distance coefficient to feature point c, ; Indicates from feature point The distance coefficient to feature point c, .

2. The control method for automatically grasping and lifting weights according to claim 1, characterized in that, ， 。 3. The control method for automatically grasping and lifting weights according to claim 1, characterized in that, The radius of the button can be automatically obtained using the following method. With distance coefficient : A laser image is generated from the point cloud data composed of laser dots obtained by scanning the weight. Then, an image recognition algorithm is used to parse the text information in the laser image to obtain the weight model or weight. Based on the weight model or weight, a weight model-weight size mapping table or a weight-weight size mapping table is consulted to obtain the radius of the button. With distance coefficient .

4. The control method for automatically grasping and lifting weights according to claim 1, characterized in that, A laser image is generated based on the point cloud data composed of laser dots obtained from scanning the weight. Then, the text information in the laser image is analyzed by an image recognition algorithm to obtain the weight of the weight. When it is determined that the tentacle on the robotic arm cannot bear the weight of the weight, the tentacle is prompted to be replaced.

5. The control method for automatically grasping and lifting weights according to claim 1, characterized in that, The tentacles are two parallel fingers that open and close along the X-axis. The roots of the two parallel fingers, when in the open state, are moved to maintain a safe distance from the feature point c along the Y-axis. The position of the tentacle root is as follows: .

6. A robotic arm, characterized in that: The system includes a controller configured with a weight-grabbing program for performing the control method for automatically grabbing lifting weights as described in any one of claims 1 to 5.

7. A robot, characterized in that: It includes a transport chassis, on which a robotic arm as described in claim 6 is mounted.

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