阅读说明：本技术 一种液压支架连杆的柔性化自动拼点方法 (Flexible automatic point splicing method for hydraulic support connecting rod ) 是由 朱红波 李福永 段青辰 凡乃峰 卢君 白海明 银升超 李臣阳 于 2021-06-30 设计创作，主要内容包括：本发明提供了一种液压支架连杆的柔性化自动拼点方法,包括以下步骤：将连杆划分为底板、主筋板、筋板、加强板和盖板五种零件,并选取各零件部分关键尺寸,进行参数化处理；对拼装、点焊程序进行参数化处理；采用视觉识别装置对各零件进行识别,计算得到底板的中心点、主筋板的中心点、筋板的中心点、盖板的中心点和加强板外圆弧段的圆心,并将这些点作为搬运机器人的抓取点；新产品上线前,向主控PLC输入上述各参数的值,启动连杆自动拼焊系统,对连杆进行自动化拼点。该液压支架连杆的柔性化自动拼点方法具有设计科学、生产效率高、易于换产、适用于多品种小批量连杆拼点的优点。(The invention provides a flexible automatic point splicing method for a hydraulic support connecting rod, which comprises the following steps: dividing the connecting rod into five parts, namely a bottom plate, a main rib plate, a reinforcing plate and a cover plate, selecting the key size of each part, and carrying out parameterization treatment; carrying out parameterization processing on the assembling and spot welding programs; identifying each part by adopting a visual identification device, calculating to obtain a central point of the bottom plate, a central point of the main rib plate, a central point of the cover plate and a circle center of an outer arc section of the reinforcing plate, and taking the points as grabbing points of the transfer robot; before a new product is on line, the values of the parameters are input into the master control PLC, and the automatic connecting rod splicing and welding system is started to automatically splice the connecting rods. The flexible automatic point splicing method for the hydraulic support connecting rods has the advantages of scientific design, high production efficiency, easiness in production change and suitability for splicing the points of the connecting rods of various types in small batches.)

1. The flexible automatic spot splicing method for the hydraulic support connecting rod is applied to an automatic spot splicing and welding system for the connecting rod, wherein the automatic spot splicing and welding system for the connecting rod comprises a master control PLC (programmable logic controller), a carrying robot, spot welding robots and an assembling platform, the assembling platform comprises a middle platform, a left side platform and a right side platform, the left side platform and the right side platform are positioned on two sides of the middle platform, and the flexible automatic spot splicing and welding method for the hydraulic support connecting rod comprises the following steps:

(1) dividing the connecting rod into five parts, namely a bottom plate, a main rib plate, a reinforcing plate and a cover plate, selecting the key size of each part, and carrying out parameterization treatment:

for the bottom plate and the cover plate, the length dimension of the notch is set to be L1, the width dimension of the middle section is set to be W1, the width dimension of the end part is set to be W2, and the thickness dimension of the plate is set to be H1;

setting the length dimension of the rib plate to be L3, the width dimension of the rib plate to be W3, the plate thickness dimension of the rib plate to be H2 and the hole center distance dimension of the rib plate and the main rib plate on the same side to be L2;

for a main rib plate, setting the hole center distance size of two holes as L4, the width size of the middle section as W4, the plate thickness size as H3 and the radius size of the outer arc as R1;

for the reinforcing plate, the width dimension of the straight line segment is set as W5, the plate thickness dimension is set as H4, and the radius dimension of the outer arc is set as R2;

(2) carrying out parameterization processing on the assembling and spot welding programs:

aiming at the bottom plate, the X-direction center line and the Y-direction center line of the bottom plate are associated with the X-direction center line and the Y-direction center line of the middle platform during assembly, the height direction takes the upper plane of the middle platform as a reference, the coordinates of the placement point of the transfer robot are (0, 0 and H1), the position coordinates of the bottom plate point fixation during spot welding are (-L4/2, W2/2 and H1), (-L1/4, W1/2, H1), (L1/4, W1/2, H1), (L4/2, W2/2, H1), (L4/2, -W2/2, H1), (L1/4, -W1/2 and H1), (-L1/4, -W1/2 and H1) (-L4/2, -W2/2 and H1);

aiming at the main rib plates, X-direction center lines of the two main rib plates are respectively associated with X-direction center lines of the left side platform or the right side platform during assembling, straight edges of the inner sides of one ends of the two main rib plates are respectively associated with two positioning blocks corresponding to the left side platform or the right side platform, the height direction takes the upper planes of the left side platform and the right side platform as a reference, and the position coordinates of the placement point of the transfer robot are the left side platform (0, -500-W4/2, H3) and the right side platform (0, 500+ W4/2 and H3);

aiming at the reinforcing plates, the circle centers of the outer circular arcs of the reinforcing plates are respectively associated with the circle centers of the outer circular arcs of the main rib plates during assembly, the height direction takes the upper surface of the main rib plates as a reference, the coordinates of the placement point of a carrying robot are left side platforms (-L4/2, -500-W4/2, H3+ H4), (L4/2, -500-W4/2, H3+ H4), right side platforms (-L4/2, 500+ W4/2, H3+ H4), (L4/2, 500+ W4/2, H3+ H4), 3 points are fixed by a single reinforcing plate during spot welding, and welding points are respectively (-L4/2, 500+ W4/2-R2, H3), (-L4/2, 500+ W4/2+ R2, H3), (-L4/2 + L5, 500+ W4/2, H3), (L4/2, 500+ W4/2-R2, H3), (L4/2, 500+ W4/2+ R2, H3), (L4/2-L5, 500+ W4/2, H3), (-L4/2, -500-W4/2+ R2, H3), (-L4/2, -500-W4/2-R2, H3), (-L4/2 + L5, -500-W4/2, H3), (L4/2, -500-W4/2+ R2, H3), (L3/2, -500-W3/2-R3, H3), (L3/2-L3, -500-W3/2, H3);

aiming at rib plates, one longer side edge of each rib plate is associated with the upper surface of the rib plate during assembly, the center line of the width direction of the rib plate is associated with the center line of the main rib plate in the X direction, the coordinates of the placement point of a carrying robot are (-L4/2 + L2+ H2, 500+ W4/2, H3+ H4), (L4/2-L2-H2, 500+ W4/2 and H3+ H4), 1 point is fixed by a single rib plate during spot welding, and the coordinates of the welding point are (-L4/2 + L2+ H2, 500+ W4/2, H3+ H4), (L4/2-L2-H2, 500+ W4/2 and H3+ H4);

aiming at the cover plate, the X-direction central line and the Y-direction central line of the cover plate are associated with the X-direction central line and the Y-direction central line of the middle platform during assembly, the height direction is associated with the upper edge of the rib plate, the coordinates of the placement point of the transfer robot are (0, H + W + H), the coordinates of the cover plate point fixation are 8 points during spot welding, and the coordinates of the positions are respectively (-L/2, W/2, H + W + H), (-L/4, W/2, H + W + H), (L/2, -W/2, H + W + H), (L/4, -W/2, H + W + H), (-L/4, -W/2, H + W + H), (-L4/2, -W2/2, H1+ W3+ H1);

(3) identifying each part by adopting a visual identification device, calculating to obtain a central point of the bottom plate, a central point of the main rib plate, a central point of the cover plate and a circle center of an outer arc section of the reinforcing plate, and taking the points as grabbing points of the transfer robot;

(4) and before the new product is on line, inputting the values of the parameters into the master control PLC, starting the automatic splicing and welding system of the connecting rod, and performing automatic splicing and welding on the connecting rod.

2. The flexible automatic point splicing method for the hydraulic support connecting rod according to claim 1, wherein in the step (3), the identification reference and algorithm of each part by the visual identification device are as follows:

aiming at the bottom plate and the cover plate, respectively taking two straight-edge crossed lines at four notches as visual identification references, photographing and identifying the four notches of the bottom plate or the cover plate, respectively determining 4 intersection points by the crossed lines at the four notches, determining a Y-direction central line by using a connection line of midpoints of two adjacent X-direction points, determining an X-direction central line by using a connection line of midpoints of two adjacent Y-direction points, wherein the intersection point of the X-direction central line and the Y-direction central line is a gripping point of the carrying robot for the bottom plate or the cover plate part;

aiming at the rib plate, taking the periphery of the rib plate as a visual identification reference, photographing and identifying the periphery outline of the rib plate, fitting an X-direction central line and a Y-direction central line by two parallel edges respectively, wherein the intersection point of the X-direction central line and the Y-direction central line is a carrying robot grabbing point of the rib plate part;

aiming at the main rib plate, respectively taking the semi-circular arcs at the two ends of the main rib plate as a visual identification reference, photographing to identify the circular arcs at the two ends of the main rib plate, respectively determining the centers of the two outer circular arcs of the part by the circular arcs at the two ends, wherein the midpoint of a connecting line of the two points is a grabbing point of the actual carrying robot for the part of the main rib plate;

and taking the outer arc and any straight line segment of the reinforcing plate as visual identification references, photographing and identifying the outer arc and the straight line segment of the reinforcing plate, fitting the center of a circle of the outer arc of the part by the outer arc, wherein the center of the circle is a gripping point of the transfer robot for the reinforcing plate part, and the straight line segment is used for calibrating the direction of the gripping point of the transfer robot.

Technical Field

The invention relates to the field of assembly and processing of large-scale structural parts, in particular to a flexible automatic point splicing method for a hydraulic support connecting rod.

Background

The hydraulic support is one of key supporting devices in the fully mechanized coal mining of a coal mine, is gradually developed towards the direction of large mining height, long service life and light weight at present, and provides higher requirements for the manufacturing quality of a main structural member of the hydraulic support. The connecting rod is used as one of key parts of the hydraulic support, and mainly has the function of keeping the stability of the support when stressed, so that the production quality of the connecting rod directly influences the safety production of the underground working face of the coal mine.

The connecting rod is a box-shaped structure formed by welding medium plates, the structure is relatively simple, the standardization degree of the shape is higher, but the size span is larger (the hole center distance range is 500-3500 mm), and the automatic assembly of the connecting rod is preliminarily realized at present. However, the existing automatic splicing method usually adopts a field teaching or off-line programming mode to program, the first piece needs to be re-taught, re-programmed or modified by using the original program during the process of changing production, the process is long in time consumption, and huge in manpower and material resources consumption, and the construction requirements of multiple varieties, small batch, frequent product change and easy product change of the automatic connecting rod splicing and welding production line cannot be met.

In order to solve the above problems, people are always seeking an ideal technical solution.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, and provides a flexible automatic point splicing method for hydraulic support connecting rods, which is scientific in design, high in production efficiency, easy to change production and suitable for splicing multiple varieties of connecting rods in small batches.

In order to achieve the purpose, the invention adopts the technical scheme that: the flexible automatic spot splicing method for the hydraulic support connecting rod is applied to an automatic spot splicing and welding system for the connecting rod, wherein the automatic spot splicing and welding system for the connecting rod comprises a master control PLC (programmable logic controller), a carrying robot, spot welding robots and an assembling platform, the assembling platform comprises a middle platform, a left side platform and a right side platform, the left side platform and the right side platform are positioned on two sides of the middle platform, and the flexible automatic spot splicing and welding method for the hydraulic support connecting rod comprises the following steps:

(1) dividing the connecting rod into five parts, namely a bottom plate, a main rib plate, a reinforcing plate and a cover plate, selecting the key size of each part, and carrying out parameterization treatment:

for the bottom plate and the cover plate, the length dimension of the notch is set to be L1, the width dimension of the middle section is set to be W1, the width dimension of the end part is set to be W2, and the thickness dimension of the plate is set to be H1;

setting the length dimension of the rib plate to be L3, the width dimension of the rib plate to be W3, the plate thickness dimension of the rib plate to be H2 and the hole center distance dimension of the rib plate and the main rib plate on the same side to be L2;

for a main rib plate, setting the hole center distance size of two holes as L4, the width size of the middle section as W4, the plate thickness size as H3 and the radius size of the outer arc as R1;

for the reinforcing plate, the width dimension of the straight line segment is set as W5, the plate thickness dimension is set as H4, and the radius dimension of the outer arc is set as R2;

(2) carrying out parameterization processing on the assembling and spot welding programs:

aiming at the bottom plate, the X-direction center line and the Y-direction center line of the bottom plate are associated with the X-direction center line and the Y-direction center line of the middle platform during assembly, the height direction takes the upper plane of the middle platform as a reference, the coordinates of the placement point of the transfer robot are (0, 0 and H1), the position coordinates of the bottom plate point fixation during spot welding are (-L4/2, W2/2 and H1), (-L1/4, W1/2, H1), (L1/4, W1/2, H1), (L4/2, W2/2, H1), (L4/2, -W2/2, H1), (L1/4, -W1/2 and H1), (-L1/4, -W1/2 and H1) (-L4/2, -W2/2 and H1);

aiming at the main rib plates, X-direction center lines of the two main rib plates are respectively associated with X-direction center lines of the left side platform or the right side platform during assembling, straight edges of the inner sides of one ends of the two main rib plates are respectively associated with two positioning blocks corresponding to the left side platform or the right side platform, the height direction takes the upper planes of the left side platform and the right side platform as a reference, and the position coordinates of the placement point of the transfer robot are the left side platform (0, -500-W4/2, H3) and the right side platform (0, 500+ W4/2 and H3);

aiming at the reinforcing plates, the circle centers of the outer circular arcs of the reinforcing plates are respectively associated with the circle centers of the outer circular arcs of the main rib plates during assembly, the height direction takes the upper surface of the main rib plates as a reference, the coordinates of the placement point of a carrying robot are left side platforms (-L4/2, -500-W4/2, H3+ H4), (L4/2, -500-W4/2, H3+ H4), right side platforms (-L4/2, 500+ W4/2, H3+ H4), (L4/2, 500+ W4/2, H3+ H4), 3 points are fixed by a single reinforcing plate during spot welding, and welding points are respectively (-L4/2, 500+ W4/2-R2, H3), (-L4/2, 500+ W4/2+ R2, H3), (-L4/2 + L5, 500+ W4/2, H3), (L4/2, 500+ W4/2-R2, H3), (L4/2, 500+ W4/2+ R2, H3), (L4/2-L5, 500+ W4/2, H3), (-L4/2, -500-W4/2+ R2, H3), (-L4/2, -500-W4/2-R2, H3), (-L4/2 + L5, -500-W4/2, H3), (L4/2, -500-W4/2+ R2, H3), (L3/2, -500-W3/2-R3, H3), (L3/2-L3, -500-W3/2, H3);

aiming at rib plates, one longer side edge of each rib plate is associated with the upper surface of the rib plate during assembly, the center line of the width direction of the rib plate is associated with the center line of the main rib plate in the X direction, the coordinates of the placement point of a carrying robot are (-L4/2 + L2+ H2, 500+ W4/2, H3+ H4), (L4/2-L2-H2, 500+ W4/2 and H3+ H4), 1 point is fixed by a single rib plate during spot welding, and the coordinates of the welding point are (-L4/2 + L2+ H2, 500+ W4/2, H3+ H4), (L4/2-L2-H2, 500+ W4/2 and H3+ H4);

aiming at the cover plate, the X-direction central line and the Y-direction central line of the cover plate are associated with the X-direction central line and the Y-direction central line of the middle platform during assembly, the height direction is associated with the upper edge of the rib plate, the coordinates of the placement point of the transfer robot are (0, H + W + H), the coordinates of the cover plate point fixation are 8 points during spot welding, and the coordinates of the positions are respectively (-L/2, W/2, H + W + H), (-L/4, W/2, H + W + H), (L/2, -W/2, H + W + H), (L/4, -W/2, H + W + H), (-L/4, -W/2, H + W + H), (-L4/2, -W2/2, H1+ W3+ H1);

(3) identifying each part by adopting a visual identification device, calculating to obtain a central point of the bottom plate, a central point of the main rib plate, a central point of the cover plate and a circle center of an outer arc section of the reinforcing plate, and taking the points as grabbing points of the transfer robot;

(4) and before the new product is on line, inputting the values of the parameters into the master control PLC, starting the automatic splicing and welding system of the connecting rod, and performing automatic splicing and welding on the connecting rod.

Based on the above, in step (3), the recognition criteria and algorithm of the visual recognition device for each part are as follows:

aiming at the bottom plate and the cover plate, respectively taking two straight-edge crossed lines at four notches as visual identification references, photographing and identifying the four notches of the bottom plate or the cover plate, respectively determining 4 intersection points by the crossed lines at the four notches, determining a Y-direction central line by using a connection line of midpoints of two adjacent X-direction points, determining an X-direction central line by using a connection line of midpoints of two adjacent Y-direction points, wherein the intersection point of the X-direction central line and the Y-direction central line is a gripping point of the carrying robot for the bottom plate or the cover plate part;

aiming at the rib plate, taking the periphery of the rib plate as a visual identification reference, photographing and identifying the periphery outline of the rib plate, fitting an X-direction central line and a Y-direction central line by two parallel edges respectively, wherein the intersection point of the X-direction central line and the Y-direction central line is a carrying robot grabbing point of the rib plate part;

aiming at the main rib plate, respectively taking the semi-circular arcs at the two ends of the main rib plate as a visual identification reference, photographing to identify the circular arcs at the two ends of the main rib plate, respectively determining the centers of the two outer circular arcs of the part by the circular arcs at the two ends, wherein the midpoint of a connecting line of the two points is a grabbing point of the actual carrying robot for the part of the main rib plate;

and taking the outer arc and any straight line segment of the reinforcing plate as visual identification references, photographing and identifying the outer arc and the straight line segment of the reinforcing plate, fitting the center of a circle of the outer arc of the part by the outer arc, wherein the center of the circle is a gripping point of the transfer robot for the reinforcing plate part, and the straight line segment is used for calibrating the direction of the gripping point of the transfer robot.

Compared with the prior art, the invention has outstanding substantive characteristics and remarkable progress, and particularly, the invention applies the parameterized program design scheme to the automatic connecting rod tailor-welding system, can realize that a set of programs are compatible with the production and processing of all connecting rods of the same type, only needs to input the drawing dimension parameters of each part of a new connecting rod again during the process of changing the production, does not need to re-teach manually or modify the programs (including a carrying program, a spot welding program, PLC logic, a motion control program and the like) manually, thereby greatly reducing the delay time of the product changing, effectively avoiding the program or data errors caused by manual modification, simultaneously realizing the data transmission and the real-time compensation of data among visual detection, a master control PLC, a carrying robot and a welding robot through the parameterized program design, and ensuring the flexibility, the stability and the reliability of a connecting rod production line, the connecting rod splicing machine has the advantages of scientific design, high production efficiency, easy production change and suitability for multiple varieties and small-batch connecting rod splicing.

Drawings

FIG. 1 is a side view of a connecting rod of the present invention.

Fig. 2 is a top view of the connecting rod of the present invention.

FIG. 3 is a schematic diagram of the visual identification reference and drawing size parameterization of the bottom plate or the cover plate in the invention.

FIG. 4 is a schematic diagram of rib plate visual identification datum and drawing dimension parameterization in the invention.

FIG. 5 is a schematic diagram of visual identification reference and drawing size parameterization of a main rib plate in the invention.

FIG. 6 is a schematic diagram of the visual recognition standard of the reinforcing plate and the parameterization of the drawing size in the invention.

FIG. 7 is a schematic diagram of the bottom plate, main rib plate, reinforcing plate, rib plate splicing points in the present invention.

Fig. 8 is a schematic view of a cover panel assembly according to the present invention.

In the figure: 1. a base plate; 2. a cover plate; 3. a rib plate; 4. a main rib plate; 5. a reinforcing plate.

Detailed Description

The technical solution of the present invention is further described in detail by the following embodiments.

As shown in fig. 1 to 8, a flexible automatic spot welding method for a hydraulic support connecting rod is applied to an automatic connecting rod tailor-welding system, which includes a master control PLC, a transfer robot, a spot welding robot, and a splicing platform, where the splicing platform includes a middle platform, and a left side platform and a right side platform located on both sides of the middle platform, and the device is an existing device in the market.

The flexible automatic point splicing method for the hydraulic support connecting rod comprises the following steps:

(1) dividing the connecting rod into five parts, namely a bottom plate 1, a main rib plate 4, a rib plate 3, a reinforcing plate 5 and a cover plate 2, selecting the key size of each part, and carrying out parameterization treatment:

for the bottom plate 1 and the lid plate 2, the notch length dimension was set to L1, the middle section width dimension was set to W1, the end width dimension was set to W2, and the plate thickness dimension was set to H1

Setting the length dimension of the rib plate 3 to be L3, the width dimension of the rib plate to be W3, the plate thickness dimension of the rib plate to be H2 and the hole center distance dimension of the rib plate 3 and the main rib plate 4 on the same side to be L2;

for the main rib plate 4, the hole center distance size of two holes is set to be L4, the width size of the middle section is set to be W4, the plate thickness size is set to be H3, and the radius size of the outer arc is set to be R1;

for the reinforcing plate 5, the straight-line segment width dimension was set to W5, the plate thickness dimension was set to H4, and the outer circular arc radius dimension was set to R2.

(2) Carrying out parameterization processing on the assembling and spot welding programs:

aiming at the bottom plates 1 of the connecting rods with different specifications, central positioning is adopted during assembly, namely an X-direction central line and a Y-direction central line of the bottom plate 1 are associated with an X-direction central line and a Y-direction central line of the middle platform, the height direction takes the upper plane of the middle platform as a reference, and the position coordinates of a placing point of a carrying robot are (0, 0 and H1); 8 points (welding spots 1-8) are fixedly arranged on the bottom plate 1 in a spot welding mode, the positions of the welding spots are automatically distributed according to five parameters of L1, L4, W1, W2 and H1, and the position coordinates of the welding spots are respectively (-L4/2, W2/2 and H1), (-L1/4, W1/2 and H1), (L1/4, W1/2 and H1), (L4/2, W2/2 and H1), (L4/2, -W2/2 and H1), (L1/4, -W1/2 and H1), (-L1/4, -W1/2 and H1), (-L4/2, -W2/2 and H1);

aiming at the main rib plates 4 of connecting rods with different specifications, X-direction central lines and inner side straight edges at one ends are used for positioning during assembly, namely the X-direction central lines of the two main rib plates 4 are respectively associated with the X-direction central lines of a left side platform or a right side platform, the inner side straight edges at one ends of the two main rib plates 4 are respectively associated with two positioning blocks corresponding to the left side platform or the right side platform, the height direction takes the upper planes of the left side platform and the right side platform as a reference, and the position coordinates of a carrying robot placing point are a left side platform (0, -500-W4/2, H3), a right side platform (0, 500+ W4/2 and H3);

aiming at the reinforcing plates 5 of connecting rods with different specifications, the centers of outer arcs are positioned during assembly, namely the centers of the outer arcs of the reinforcing plates are respectively associated with the centers of the outer arcs of the main rib plates 4, the height direction takes the upper surface of the main rib plates 4 as a reference, and the coordinates of the placement positions of the carrying robot are left side platforms (-L4/2, -500-W4/2, H3+ H4), (L4/2, -500-W4/2, H3+ H4), right side platforms (-L4/2, 500+ W4/2, H3+ H4), (L4/2, 500+ W4/2, H3+ H4); 3 points are fixed by a single reinforcing plate 5 during spot welding, the spot welding position is automatically distributed according to five parameters of L4, L5, R2, W4 and H3, the coordinates of a welding point 9-a welding point 20 are respectively (-L4/2, 500+ W4/2-R2 and H3), (-L4/2, 500+ W4/2+ R2 and H3), (-L4/2 + L5, 500+ W4/2, H3), (L4/2, 500+ W4/2-R2 and H3), (L4/2, 500+ W4/2+ R4, H4), (L4/2-L4, 500+ W4/2, H4), (-L4/2, -500-W4/2+ R4 and H4) (-L4/72), -500-W4/2, H3), (L4/2, -500-W4/2+ R2, H3), (L4/2, -500-W4/2-R2, H3), (L4/2-L5, -500-W4/2, H3);

aiming at rib plates 3 of connecting rods with different specifications, a longer side edge (L3) and a width direction center line (Y-direction center line in fig. 4) are adopted for positioning during assembly, namely, the longer side edge of the rib plate 3 is associated with the upper surface of a reinforcing plate 5, the width direction center line of the rib plate 3 is associated with an X-direction center line of a main rib plate 4, and the coordinates of the placement point of a carrying robot are (-L4/2 + L2+ H2, 500+ W4/2, H3+ H4), (L4/2-L2-H2, 500+ W4/2 and H3+ H4); 1 point is fixedly arranged on a single rib plate 3 during spot welding, the position of a welding point is automatically distributed according to six parameters of L2, L4, W4, H2, H3 and H4, and the position coordinates of the welding point 21-22 are respectively (-L4/2 + L2+ H2, 500+ W4/2, H3+ H4), (L4/2-L2-H2, 500+ W4/2 and H3+ H4);

aiming at cover plates 2 of connecting rods with different specifications, central positioning is adopted during assembly, namely an X-direction central line and a Y-direction central line of the cover plate 2 are associated with an X-direction central line and a Y-direction central line of a middle platform, the height direction is associated with the upper side (the upper side of a wide side) of a rib plate 3, and the position coordinates of a placing point of a carrying robot are (0, H1+ W3+ H1); 8 points are fixed by the cover plate 2 during spot welding, (welding spots 23-30), the positions of the welding spots are automatically distributed according to six parameters of L1, L4, W1, W2, W3 and H1, and the position coordinates of the welding spots are respectively (-L4/2, W2/2, H2 + W2 + H2), (-L2/4, W2/2, H2 + W2 + H2), (L2/4, W2/2, H2 + W2 + H2), (L2/2, W2/2, H2 + W2 + H2), (L2/4, -W2/2, H2 + W2 + H2), (-L2/4, -W2/2, H2 + W2 + H2) and (-W2 + H2).

(3) And identifying each part by adopting a visual identification device, wherein the identification reference and algorithm of each part by the visual identification device are as follows:

aiming at the bottom plate 1 and the cover plate 2, respectively taking two straight-edge intersecting lines at four notches as visual identification references, photographing and identifying the four notches of the bottom plate 1 or the cover plate 2, respectively determining 4 intersection points by the four intersecting lines at the notches, determining a Y-direction central line by using a connecting line of midpoints of two adjacent points in the X direction, determining an X-direction central line by using a connecting line of midpoints of two adjacent points in the Y direction, wherein the intersection point of the X-direction central line and the Y-direction central line is a gripping point of the transfer robot for the bottom plate 1 or the cover plate 2;

aiming at the rib plate 3, taking the periphery of the rib plate 3 as a visual identification reference, photographing and identifying the periphery outline of the rib plate 3, fitting an X-direction central line and a Y-direction central line by two parallel edges respectively, wherein the intersection point of the X-direction central line and the Y-direction central line is a carrying robot grabbing point of a rib plate 3 part;

aiming at the main rib plate 4, respectively taking the semi-circular arcs at the two ends of the main rib plate 4 as visual identification standards, photographing and identifying the circular arcs at the two ends of the main rib plate 4, respectively determining the centers of the two outer circular arcs of the part by the circular arcs at the two ends, wherein the midpoint of a connecting line of the two points is a grabbing point of the main rib plate 4 part actual carrying robot;

aiming at the reinforcing plate 5, taking the outer arc and any straight line segment of the reinforcing plate 5 as visual identification references, photographing and identifying the outer arc and the straight line segment of the reinforcing plate 5, fitting the center of the outer arc of the part by the outer arc, wherein the center of the circle is a gripping point of the transfer robot for the reinforcing plate 5, and the straight line segment is used for calibrating the direction of the gripping point of the transfer robot.

(4) Before a new product is on line, according to drawings of parts of the connecting rod, the parameters are input into a system through a parameter input interface of the master control PLC, and the correctness of input data is ensured for system calling and comparison and identification; the automatic connecting rod tailor-welding system is started, the vision recognition device shoots and calculates all parts to obtain detection results, the detection results are sent to the master control PLC through parameters, meanwhile, the master control PLC system sends the detection data to the carrying robot and the spot welding robot in real time, and the carrying robot and the spot welding robot correct the placing position and the welding position according to the received parameters, so that normal and stable production of the product is achieved.

Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention and not to limit the same; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art will understand that: modifications to the specific embodiments of the invention or equivalent substitutions for parts of the technical features may be made; without departing from the spirit of the present invention, it is intended to cover all aspects of the invention as defined by the appended claims.