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CN-118164148-B - Variable-speed operation assembly line and manipulator grabbing system

CN118164148BCN 118164148 BCN118164148 BCN 118164148BCN-118164148-B

Abstract

The application provides a variable-speed running assembly line and a manipulator grabbing system, wherein the speed V of a running water conveying belt when a manipulator grabs a product N_k is represented by a conversion formula of V= (Vmax-Vmin)/(Ymax-Ymin) x YS+Vmin/p, and the speed of the running water conveying belt when the manipulator grabs the product N_k is obtained in real time according to the conversion formula. The manipulator can be under the condition that the flowing water conveyer belt is not suspended, the products with different shapes and different heights are positioned and grabbed in real time, the products are placed at the designated positions according to the designated angles, the situation that the products are repeatedly grabbed or the products are not grabbed is effectively avoided, the running speed of the flowing water conveyer belt can be automatically adjusted in real time, and the efficiency of grabbing the products by the manipulator is greatly improved.

Inventors

  • LIN XIAOYAN
  • JIANG JUN
  • FANG XUE
  • HUANG QINGMIAO

Assignees

  • 琦星智能科技股份有限公司

Dates

Publication Date
20260508
Application Date
20221208

Claims (9)

  1. 1. The variable speed operation assembly line is characterized in that when a manipulator grabs a product N_k, a speed V conversion formula of a running water conveyor belt is as follows: V=(Vmax-Vmin)/(Ymax-Ymin)×YS+ Vmin/p wherein, vmax is the maximum conveying speed (mm/s) of the running water conveying belt, and Vmin is the minimum conveying speed (mm/s) of the running water conveying belt; ymax is the distance between the 3D line scanning position and the rear boundary line, ymin is the distance between the 3D line scanning position and the front boundary line, YS is the difference value of the y values of the coordinates of the products n_k and the products n_k+1 in the detection queue; when 0< YS < YSmax, YS=Y_K+1-Y_K, namely the running water conveyor belt changes speed according to a speed change formula; the coordinate Y values are respectively marked as Y_K and Y_K+1, wherein p in the formula is the running distance of one pulse of the flow conveyor belt, namely the line spacing among pixels of the acquired image, and the calculated speed V is calculated in pulse/s; Obtaining the speed of the continuous water conveyor belt when the real-time manipulator grabs the product N_k according to a speed conversion formula; When YS > YSmax, YS= YSmax, namely when the distance between the product N_k and the product N_k+1 is far, the running water conveyor belt keeps the maximum speed running; when YS <0, namely Y_K >0, Y_K+1=0, namely only one object of the product N_K exists in the current detection queue, and the running water conveyor belt keeps the original speed to run without changing the speed; When y_k=0, y_k+1=0, let ys= YSmax, i.e. when the current inspection queue has no object, the running water conveyor belt keeps running at maximum speed.
  2. 2. A manipulator grabbing system is characterized in that the system operation comprises the following steps: Step one, establishing real-time static positions of the manipulator and the flow conveyor belt; Step two, a 3D line scanning camera acquires 3D images of products with different shapes passing through a flow conveyor belt, and the 3D line scanning camera is utilized to process the 3D images to obtain product matching templates with different shapes, wherein the step two can be completed in advance; Step three, the running of the running water conveyor belt is started, the running initial speed of the running water conveyor belt is set to be Vmax (unit: mm/s), and the running initial speed is recorded; step four, acquiring images of products on the flow conveyor belt by adopting a 3D line scanning camera; step five, performing shape matching on the product image and the product matching template by using a 3D line scanning camera, then obtaining position, height and rotation data of products in different shapes, recording the data in a detection queue, and transmitting the data to an industrial personal computer and a PLC in real time; step six, integrating the array in the detection queue by the industrial personal computer; Step seven, the industrial personal computer calculates a PLC count value Y1 of a boundary line before the product reaches and a PLC count value Y2 of a boundary line after the product reaches according to data in the product detection queue, and sends the Y1 and Y2 to the PLC in real time; Step eight, when grabbing the product N_K, the PLC compares the product N_K with Y1 and Y2 of the product N_K in a detection queue sent by the industrial personal computer according to the real-time count value of the PLC, and the method comprises the following steps: Step S1, a difference YS of the coordinate Y values of the products N_K and the products N_K+1 in a detection queue is calculated by the PLC between [ Y1, Y2] of the products N_K, namely the PLC real-time count value is between Y1 and Y2; Step S2, calculating the speed of the manipulator for grabbing the product N_k according to a speed transformation formula, wherein the speed transformation formula is as follows: V=(Vmax-Vmin)/(Ymax-Ymin)×YS+ Vmin/p wherein, vmax is the maximum conveying speed (mm/s) of the running water conveying belt, and Vmin is the minimum conveying speed (mm/s) of the running water conveying belt; ymax is the distance between the 3D line scanning position and the rear boundary line, ymin is the distance between the 3D line scanning position and the front boundary line, and YS is the difference value of the y values of the coordinates of the product n_k and the product n_k+1 in the detection queue: a) When YS > YSmax, YS= YSmax, namely product N_k, and product N_k+1 are far away, the running water conveyor belt keeps running at maximum speed; b) When 0< YS < YSmax, YS=Y_K+1-Y_K, namely the running water conveyer belt changes speed according to a speed change formula; c) When YS <0, namely Y_K >0, Y_K+1=0, namely only one object of the product N_K exists in the current detection queue, and the running water conveyor belt keeps the original running speed without changing the speed; d) When Y_K=0 and Y_K+1=0, YS= YSmax, namely when the current detection queue has no object, the running water conveyor belt keeps running at the maximum speed; p in the formula is the running distance of one pulse of the flow conveyor belt, and is also the line spacing between pixels of the acquired image, and the calculated speed V is calculated in the unit of pulse/s; Step S3, the PLC performs speed change according to the calculated speed V, calculates an offset value R, and sends the R value to the industrial personal computer, wherein a calculation formula is R=VT Wherein V is the current speed of the running water conveyor belt, T is the time which is manually set and is longer than the communication period, and R is the deviation of the set grabbing point from the standby position of the manipulator; step S4, the industrial personal computer calculates a pose transformation matrix of the standby position of the product to be grabbed and the manipulator according to the R value sent by the PLC, and position data, height data and rotation data obtained by image processing of the product, and sends the pose transformation matrix to the manipulator; step S5, when the real-time count value of the PLC reaches Y1+R of the product N_K, namely the product is sent to a designated grabbing point of the PLC, the PLC informs the manipulator to grab; Step S6, immediately informing the PLC to compare the next group of data after the manipulator grabs the product, judging whether the current count value is between Y1 and Y2 of the product N_K+1, calculating a difference YS of the product Y_K+1 and the product Y_K+2, and then changing the speed of the flow conveyor belt according to the YS; and step S7, simultaneously, the manipulator places the product at a designated position according to a designated angle according to the rotation data and the shape data obtained by the image processing of the product, and after the placement is successful, the manipulator returns to a standby position to wait or execute a new grabbing instruction of the PLC.
  3. 3. A robot hand grasping system according to claim 2, wherein the real-time static position is specifically a robot hand position and a distance between a 3D line scan camera and a robot hand grasping area in a static state is calculated and established, a robot hand standby position and a robot hand grasping area for grasping a product are established, a standby position of the robot hand is determined at the same time, a distance Ymin between the 3D line scan position and a front boundary line is calculated, a distance Ymax between the 3D line scan position and a rear boundary line is calculated, an encoder detects and collects running speed, distance and position of a running water conveyer belt and sends the running speed, distance and position to a PLC, a distance between the 3D line scan position and the front boundary line is calculated, and a distance between the 3D line scan position and the rear boundary line is calculated.
  4. 4. The manipulator grabbing system as claimed in claim 2, wherein the 3D line scan camera is configured to acquire a 3D image of the product at a standard photographing position, and the standard photographing position is that the running water conveyer belt is provided with a virtual 3D line scan camera line.
  5. 5. The manipulator grabbing system as claimed in claim 2, wherein the product image acquisition is performed by setting an image overlapping length, the overlapping length is larger than a maximum product length, and an actual length M of one image is a shooting length of the 3D line scanning camera minus the image overlapping length.
  6. 6. The manipulator grabbing system according to claim 2, wherein the data in the overlapping portion of the current detection queue is analyzed, if the coordinate x value is close and the coordinate Y value is different from the Y value of the previous image product by M, M is an actual length of an image, the product is repeatedly shot, the detection queue is removed, the integrated detection queue is ordered according to the coordinate Y value, and the integrated detection queue preferentially processes the product with small Y value, namely, the product at the front of the continuous belt is denoted as product N_1, product N_2, product N_3.
  7. 7. A manipulator gripping system according to claim 3, wherein Y1 and Y2 satisfy the following relationship: Y1=Y+Ymin/p+n×M;Y2=Y+Ymax/p+n×M; Wherein Y represents the Y coordinate of the product after image processing, ymin is the distance between the 3D line scanning position and the front boundary line, ymax is the distance between the 3D line scanning position and the rear boundary line, p is the line spacing between adjacent pixels in the image acquired by the 3D line scanning camera, n is the number of pictures shot by the camera, and M is the number of lines of the actual picture of the pictures shot by the camera.
  8. 8. A manipulator gripping system according to claim 2, characterised in that: if the real-time count value of the PLC is smaller than Y1, the PLC does not do any action, and waits for the actual count value to be equal to Y1; if the real-time count value of the PLC is larger than Y2, the PLC controls the running water conveyor belt to stop.
  9. 9. A manipulator grabbing system according to claim 2, wherein the manipulator grabbing system comprises a production line, a manipulator, a 3D line scanning camera, a running water conveyor belt, an encoder, a camera fixing frame and a control system, the manipulator, the running water conveyor belt and the camera fixing frame are mounted on the production line, the 3D line scanning camera is fixed on the upper portion of the camera fixing frame, a lens of the 3D line scanning camera is opposite to the running water conveyor belt and is used for photographing and imaging products on the running water conveyor belt running at a constant speed, the manipulator is located on the rear side of the camera fixing frame and can clamp the products conveyed by the running water conveyor belt, the direction of the products on the running water conveyor belt is defined as a y-axis direction of operation of the manipulator, the encoder is mounted on the side edge position of the running water conveyor belt and used for detecting and collecting running water conveyor belt data in real time, the control system comprises a PLC, an industrial control computer and a vision tool, the control system is electrically connected with the manipulator, the 3D line scanning camera, the running water conveyor belt and the encoder, and the industrial control computer are in charge of being communicated with the manipulator, and the manipulator is triggered by the PLC.

Description

Variable-speed operation assembly line and manipulator grabbing system Technical Field The application provides a variable-speed operation assembly line and a manipulator grabbing system, and particularly relates to the technical field of industrial robots. Background Industrial automation is an industrial production mode in which a production line automatically operates without direct intervention of workers, and grabbing by using industrial manipulators on the production line is a very important technology for industrial automation. At present, most industrial manipulators on a production line grab based on a vision system, and a camera shoots a product to obtain position information of the product so as to guide the industrial manipulators to grab according to the position information. There are currently robotic grasping systems based on 2D vision, which are used to grasp products of the same height. Products on a production line move continuously, and the shapes and heights of the products are possibly different, so that the real-time positioning and grabbing work by adopting a mechanical arm in the movement of the products is difficult to realize. If the 2D vision system is used for stopping grabbing the water flowing conveyor belt again, the grabbing efficiency of the manipulator is low. In addition, the visual system combined with the 2D visual system is adopted to continuously change the photographing time interval setting, so that image recognition is carried out. The time interval setting of shooing is constantly changed, the condition that the industrial manipulator comes not to snatch can appear when the product is more on the continuous water conveyer belt to take a lot of shooting or miss to take to same product easily, leads to the product to flow out of production line. Disclosure of Invention The invention aims to solve the problems, and provides a variable speed operation assembly line and a manipulator grabbing system, which can grab products with different shapes and different heights on a running water conveyer belt in variable speed operation, overcome or reduce the occurrence of missing grabbing or missing grabbing products on the running water conveyer belt, and the variable speed operation assembly line for grabbing the products by a manipulator is characterized in that a speed V conversion formula of the running water conveyer belt when the manipulator grabs the products N_k: V=(Vmax-Vmin)/(Ymax-Ymin)×YS+Vmin/p Wherein, vmax is the maximum conveying speed (mm/s) of the running water conveying belt, vmin is the minimum conveying speed (mm/s) of the running water conveying belt, ymax is the distance between the 3D line scanning position and the rear boundary line, ymin is the distance between the 3D line scanning position and the front boundary line, YS is the difference value of the coordinate y values of the products N_k and the products N_k+1 in the detection queue; When 0< YS < YSmax, YS=Y_K+1-Y_K, namely the running water conveyor belt changes speed according to a speed change formula; the coordinate Y values are respectively marked as Y_K and Y_K+1, wherein p in the formula is the running distance of one pulse of the flow conveyor belt, namely the line spacing among pixels of the acquired image, and the calculated speed V is calculated in pulse/s; And obtaining the speed of the continuous water conveyor belt when the real-time manipulator grabs the product N_k according to the speed conversion formula. Further, when YS > YSmax, let ys= YSmax, i.e. product n_k and product n_k+1 are far away, the running water conveyor keeps running at maximum speed, when YS <0, i.e. y_k >0, y_k+1=0, i.e. there is only one object of product n_k in the current detection queue, the running water conveyor keeps running at original speed, without changing speed, when y_k=0, y_k+1=0, let ys= YSmax, i.e. there is no object in the current detection queue, the running water conveyor keeps running at maximum speed. The manipulator grabbing system is characterized by comprising the following steps of: Step one, establishing real-time static positions of the manipulator and the flow conveyor belt; Step two, a 3D line scanning camera acquires 3D images of products with different shapes passing through a flow conveyor belt, and the 3D line scanning camera is utilized to process the 3D images to obtain product matching templates with different shapes, wherein the step two can be completed in advance; Step three, the running of the running water conveyor belt is started, the running initial speed of the running water conveyor belt is set to be Vmax (unit: mm/s), and the running initial speed is recorded; step four, acquiring images of products on the flow conveyor belt by adopting a 3D line scanning camera; step five, performing shape matching on the product image and the product matching template by using a 3D line scanning camera, then obtaining position, height and rotation data of products in different sha