Intelligent laser cladding system and method for stainless steel plate of bridge support

Abstract

The invention discloses an intelligent laser cladding system and method for a stainless steel plate of a bridge support, and aims to realize accurate and efficient cladding processing and improve the surface performance of a material. The system comprises a six-axis multi-joint robot, a laser tracker, a laser cladding head, a wire feeding mechanism and an electrical control system. The robot controls the laser cladding head to move, the laser tracker monitors and adjusts the cladding process, the laser cladding head provides laser energy, the wire feeding mechanism supplies cladding wires, and the electric control system coordinates all the components to work. The method comprises the steps of matrix pretreatment, cladding system parameter setting, intelligent laser cladding and cladding layer finish machining and polishing treatment. By accurately controlling conveying of laser beams and metal wires and motion parameters of all parts, intelligent high-quality cladding machining of workpieces made of different materials and in different shapes is achieved, and the device is suitable for cladding of stainless steel plates with planes, convex surfaces and concave surfaces. According to the system and the method, the cladding precision and efficiency are improved, the cost is reduced, and the system and the method have wide industrial application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of bridge bearing processing, and more specifically, relates to an intelligent laser cladding system and method for bridge bearing stainless steel plates. Background Art

[0002] Stainless steel plates for bridge bearings are generally divided into flat stainless steel plates and spherical stainless steel plates, with a thickness of about 1.5 to 3 mm. They are usually combined with polymer wear-resistant materials to form sliding or rotating pairs of bridge bearings. The degree of fit between them and the substrate directly affects the performance of the friction pair of the bridge bearing, and thus affects the seismic isolation function and structural safety of the bearing. At present, stainless steel plates for bridge bearings are generally coated on the steel substrate by welding methods such as argon arc welding. The technical requirements are that the stainless steel plates and the steel substrate are tightly fitted without hollows to ensure the stability of the bridge bearing during sliding. However, the existing welding process can only achieve full welding of the outer periphery of the stainless steel, and cannot effectively ensure that the entire contact surface of the inner side and the center is tightly fitted with the steel substrate, which is prone to quality defects such as hollows. Especially for large-sized stainless steel plates, only the peripheral welding can be guaranteed to fit, and there is a risk of hollows in the central area. The sliding of the bridge bearing is mainly concentrated in the central area, which has a certain impact on the function of the bearing friction pair and is prone to quality risks.

[0003] With the development of laser cladding technology, bridge bearings have begun to use laser cladding technology to clad a stainless steel layer on the surface of the steel substrate. As disclosed in the patent document with the publication number CN202211583532.3, the present invention provides a laser cladding stainless steel bearing plate and its manufacturing process. The surface of the bearing plate of the present invention adopts laser cladding technology, and stainless steel powder is clad to the surface of the substrate of the bearing plate cladding area by a powder feeding laser cladding method, so as to avoid the problem that the stainless steel plate is pressed on the surface of low-carbon steel or cast steel and the structure is "non-integrated component" and easy to bulge; avoid the use of welding, the welding material at the weld will produce chemical and electrochemical corrosion, and the situation of desoldering; it is not easy to desolder, and the surface contour can be guaranteed, so as to solve the problem of desoldering that always exists for stainless steel cladding on concave and convex surfaces, but the process adopts a powder cladding scheme, the cladding efficiency is low, and the utilization rate of powder materials is not high; and the cladding equipment adopts CNC rotary equipment, which is easily limited by the product structure size, the cladding path cannot be automatically adjusted, and the intelligence level is low, which affects the cladding quality. Summary of the invention

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides an intelligent laser cladding system and cladding method for bridge bearing stainless steel plates. The intelligent cladding system aims to achieve complete metallurgical bonding of the stainless steel plate and the steel substrate, improve material utilization, and introduce an intelligent system to adapt to the complex shapes and material changes of different bridge bearing surfaces.

[0005] According to a first aspect of the present invention, there is provided an intelligent laser cladding system for bridge bearing stainless steel plates, comprising:

[0006] Laser cladding head, used to provide laser energy to melt the cladding material and substrate,

[0007] A six-axis multi-joint robot is used to control and move the laser cladding head in multiple directions.

[0008] The laser tracker uses high-precision sensors and algorithms to automatically identify the cladding range, calculate the optimal cladding path, monitor the position of the laser cladding head and the cladding path in real time, and provide real-time feedback. The algorithm includes an automatic identification algorithm for the cladding range and path:

[0009] The Canny edge detection algorithm is used to identify the boundary of the cladding area. The Canny edge detection algorithm mainly includes the following steps:

[0010] ① Use a high-resolution camera to capture images of the area to be clad, ② Gaussian filtering to reduce noise, ③ calculate the gradient amplitude and direction, ④ non-maximum suppression, ⑤ dual threshold detection and edge connection, where the gradient amplitude G and direction θ can be calculated by the following formula:

[0011]

[0012] Among them, G x and G y are the gradients of the image in the x and y directions respectively;

[0013] After determining the boundary of the cladding area, the Otsu's method can be used to automatically determine the optimal threshold T to segment the image into the cladding area and the background area. The goal of Otsu's method is to minimize the intra-class variance, that is, to maximize the inter-class variance. The threshold T can be calculated by the following formula:

[0014]

[0015] Among them, ω0(T) and ω1(T) are the probabilities of the background and target areas, respectively, and μ0(T) and μ1(T) are the means of the background and target areas, respectively;

[0016] A wire feeding mechanism is used to provide cladding material; the cladding material is cladding wire, the melting process is gentle and splash-free, and a high utilization rate of the material is achieved;

[0017] As well as the electrical control system, the core part of the entire laser cladding system, it is used to coordinate and control the work of other components to achieve intelligent cladding.

[0018] Furthermore, the algorithm also includes calculating the optimal cladding path: based on the identified cladding area, a path planning algorithm A* algorithm is used to find the optimal path from the starting point to the end point. The A* algorithm is specifically as follows:

[0019] Define the heuristic function h(n) and the cost function g(n), the cost function f(n) is:

[0020] f(n)=g(n)+h(n)

[0021] Among them, g(n) is the actual cost from the starting node to the current node n, and h(n) is the estimated cost from the current node n to the target node;

[0022] The heuristic function h(n) is used to estimate the cost from the current node to the target node, which uses the Euclidean distance:

[0023]

[0024] Among them, x n , x g are the x-axis coordinates of the current node n and the target node g, n ,y g are the coordinates of the current node n and the target node g on the y-axis,

[0025] When the target node is found, the path from the start node to the target node is reconstructed by tracing the parent nodes. This process provides the actual route taken by the algorithm to reach the target node, showing the sequence of nodes in the optimal path, and efficiently finding the optimal path.

[0026] Furthermore, the algorithm also includes a real-time monitoring algorithm for the position of the laser cladding head and the cladding path: the laser tracker obtains the position of the laser cladding head in real time through a high-precision sensor, and the actual position of the laser cladding head is (x t ,y t ), the theoretical position on the predetermined path is (x d ,y d ), then the position error (e x , e y ) can be expressed as:

[0027] e x =x d -x t

[0028] e y =y d -y t

[0029] According to the position error, the PID controller is used to correct the position error and adjust the path of the laser cladding head to ensure the accuracy of the cladding path. The output u(t) of the PID controller is:

[0030]

[0031] Where, e(t) is the position error, K p , K i , K d are the parameters of the PID controller;

[0032] Furthermore, the laser cladding head is internally provided with a high-power laser, which can generate a laser beam with a high energy density for melting the cladding material and the substrate to form a cladding layer.

[0033] Furthermore, the six-axis multi-joint robot has six-degree-of-freedom movement and rotation functions, and drives the laser cladding head to provide precise spatial positioning and motion control during the cladding process.

[0034] Furthermore, the wire feeding mechanism ensures that the delivery speed and amount of the cladding material match the moving speed of the laser cladding head and the cladding requirements through precise motor control and sensor feedback.

[0035] Furthermore, the electrical control system is used to coordinate the motion control of various components, reasonably adjust the parameters such as cladding power, cladding path, wire feeding speed according to the cladding requirements, and monitor the state and quality of the cladding process in real time.

[0036] According to another aspect of the present invention, a cladding method using the above-mentioned bridge bearing stainless steel plate intelligent laser cladding system is provided, comprising the following specific steps:

[0037] S100: Preparation of substrate and cladding materials: pre-treat the substrate and select cladding wire that meets the requirements;

[0038] S200: Cladding system parameter setting: Start the intelligent laser cladding system, import product drawings, specify the cladding range and thickness, adjust the laser power parameters and wire feeding speed, and automatically plan the cladding path;

[0039] S300: Intelligent laser cladding: The six-axis multi-joint robot drives the laser cladding head to move to the starting point of the path, the wire feeding mechanism delivers the wire, the laser cladding head outputs the laser beam, and the laser tracker monitors the cladding path and cladding layer thickness in real time and transmits them to the electrical control system, making real-time adjustments to the cladding quality and path, and finally completing the predetermined cladding requirements;

[0040] S400: Finishing and polishing of cladding layer: Finish the cladding layer to the required thickness, and then polish it to the required roughness to meet the use requirements.

[0041] Furthermore, the cladding wire is a stainless steel wire, the wire diameter is between φ0.2 mm and φ3 mm, the wire feeding speed of the wire feeding mechanism is between 1 and 25 m / min, and the laser power of the laser cladding head can be adjusted to 3 to 12 kW.

[0042] Furthermore, the thickness of the cladding layer is controlled by adjusting the wire feeding speed of the wire feeding mechanism and the moving speed of the laser beam, and the thickness of the stainless steel cladding layer is between 0.5 mm and 5 mm.

[0043] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0044] 1. The present invention introduces an intelligent laser cladding system, which realizes free movement and rotation through a six-axis multi-joint robot. The system has a high degree of freedom and can accurately adjust and control the laser beam power, the wire feeding speed of the metal wire, the motion parameters of each component and the cladding path according to the imported drawing product to adapt to the complex shapes and material changes of different bridge bearing surfaces. It has a wide range of applications, a high degree of intelligence, and improves the cladding quality.

[0045] 2. The intelligent cladding system of the present invention uses wire for laser cladding. Through precise cladding head design and metal wire selection, the metal wire will be completely melted. The melting process is gentle and splash-free, which is more environmentally friendly and safe. The wire utilization rate can reach 99%, the material utilization rate is high, and the cost is reduced.

[0046] 3. The intelligent laser cladding system of the present invention, through the cooperation of the wire feeding mechanism and the laser cladding head, melts the wire and the surface of the substrate at the same time and mixes them together to form a cladding layer. The cladding layer and the substrate achieve a dense metallurgical bond, ensuring that the stainless steel cladding layer and the substrate are completely close to each other, reliably solving the internal hollowing problem of the clad stainless steel plate, and improving the stability and safety of the support structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a diagram showing the structure of an intelligent laser cladding system for stainless steel plates for bridge supports according to an embodiment of the present invention;

[0048] Figure 2 This is a schematic diagram of a cladding method of an intelligent laser cladding system for bridge bearing stainless steel plates according to an embodiment of the present invention;

[0049] Figure 3 This is a schematic diagram of intelligent laser cladding processing of a flat stainless steel plate for a bridge support according to an embodiment of the present invention;

[0050] Figure 4 This is a schematic diagram of intelligent laser cladding processing of a convex stainless steel plate of a bridge support according to an embodiment of the present invention;

[0051] Figure 5 This is a schematic diagram of intelligent laser cladding processing of a concave stainless steel plate of a bridge support according to an embodiment of the present invention;

[0052] Figure 6This is a schematic diagram of the overall structure of a stainless steel plate seismic isolation support produced by the intelligent laser cladding system according to an embodiment of the present invention;

[0053] In all the drawings, the same figure marks represent the same technical features, specifically: 1-steel substrate, 2-stainless steel laser cladding layer, 3-intelligent laser cladding system, 4-upper seat plate, 5-ball crown, 6-middle seat plate, 7-lower seat plate, 8-wear-resistant slide plate. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0055] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0056] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0057] In this patent, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the sentence "includes..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0058] like Figure 1As shown, an embodiment of the present invention provides an intelligent laser cladding system for stainless steel plates for bridge bearings, including a laser cladding head, a six-axis multi-joint robot, a laser tracker, a wire feeding mechanism, and an electrical control system. The laser cladding head provides laser energy for cladding, the six-axis multi-joint robot controls the movement of the laser cladding head, the laser tracker is responsible for monitoring the cladding process and adjusting it in real time, the wire feeding mechanism provides cladding materials, and the electrical control system is the brain of the entire system, responsible for coordinating and controlling the work of other components to achieve precise cladding effects. Among them,

[0059] The laser cladding head mainly provides laser energy output for melting the wire and substrate to form cladding. It is equipped with a high-power laser that can generate a high-energy-density laser beam. The high-energy laser beam is used as a heat source to quickly melt the substrate surface and the cladding material to form a molten pool, and then forms a cladding layer through rapid solidification.

[0060] The six-axis multi-joint robot has six-degree-of-freedom movement and rotation functions, provides precise spatial positioning and motion control during the cladding process, and can drive the laser cladding head to operate according to a predetermined path through the electrical control system to meet the cladding requirements of stainless steel plates of different sizes and shapes;

[0061] The laser tracker uses high-precision sensors and algorithms to automatically identify the cladding range, calculate the optimal cladding path, guide the laser cladding head to run along a predetermined trajectory, and monitor the position and cladding path of the laser cladding head in real time, and transmit the information to the electrical control system to achieve real-time adjustment of the cladding thickness and path, thereby ensuring the accuracy and stability of the cladding process;

[0062] The laser tracker algorithm includes:

[0063] (1) Automatic identification algorithm of cladding range and path

[0064] The Canny edge detection algorithm is used to identify the boundary of the cladding area. The Canny edge detection algorithm mainly includes the following steps:

[0065] ① Use a high-resolution camera to capture images of the area to be clad.

[0066] ②Gaussian filtering for noise reduction,

[0067] ③Calculate the gradient magnitude and direction,

[0068] ④ Non-maximum suppression,

[0069] ⑤Dual threshold detection and edge connection,

[0070] Among them, the gradient amplitude G and direction θ can be calculated by the following formula:

[0071]

[0072] Among them, G x and G y are the gradients of the image in the x and y directions respectively;

[0073] After determining the boundary of the cladding area, the Otsu's method can be used to automatically determine the optimal threshold T to segment the image into the cladding area and the background area. The goal of Otsu's method is to minimize the intra-class variance, that is, to maximize the inter-class variance. The threshold T can be calculated by the following formula:

[0074]

[0075] Among them, ω0(T) and ω1(T) are the probabilities of the background and target areas, respectively, and μ0(T) and μ1(T) are the means of the background and target areas, respectively;

[0076] (2) Calculate the optimal cladding path

[0077] Based on the identified cladding area, the path planning algorithm A* algorithm is used to find the optimal path from the starting point to the end point. The A* algorithm is specifically as follows:

[0078] Define the heuristic function h(n) and the cost function g(n), the cost function f(n) is:

[0079] f(n)=g(n)+h(n)

[0080] Among them, g(n) is the actual cost from the starting node to the current node n, and h(n) is the estimated cost from the current node n to the target node.

[0081] The heuristic function h(n) is used to estimate the cost from the current node to the target node, which uses the Euclidean distance:

[0082]

[0083] Among them, x n , x g are the x-axis coordinates of the current node n and the target node g, n ,y g are the coordinates of the current node n and the target node g on the y-axis,

[0084] When the target node is found, the path from the start node to the target node is reconstructed by tracing the parent nodes. This process provides the actual route taken by the algorithm to reach the target node, showing the sequence of nodes in the optimal path, and efficiently finding the optimal path.

[0085] (3) Real-time monitoring algorithm for laser cladding head position and cladding path

[0086] The laser tracker obtains the position of the laser cladding head in real time through high-precision sensors (such as laser rangefinders, encoders, etc.). Suppose the actual position of the laser cladding head is (x t ,y t ), the theoretical position on the predetermined path is (x d ,y d ), then the position error (e x , e y ) can be expressed as:

[0087] e x =x d -x t

[0088] e y =y d -y t

[0089] According to the position error, the PID controller is used to correct the position error and adjust the path of the laser cladding head to ensure the accuracy of the cladding path. The output u(t) of the PID controller is:

[0090]

[0091] Where, e(t) is the position error, K p , K i , K d are the parameters of the PID controller;

[0092] The wire feeding mechanism mainly provides cladding wire for laser cladding. During the cladding process, it delivers the cladding material (such as stainless steel wire) to the bottom of the laser cladding head at a predetermined speed and amount, and melts together with the base material under the action of the laser beam to achieve cladding and form a cladding layer. Through precise motor control and sensor feedback, it can ensure that the delivery speed and amount of the cladding material match the moving speed of the laser cladding head and the cladding requirements;

[0093] As the core part of the entire laser cladding system, the electrical control system is used to coordinate the motion control of various components and reasonably adjust the parameters such as cladding power, cladding path, wire feeding speed, etc. according to the cladding requirements. By receiving information from sensors and human-computer interaction interfaces, the electrical control system can monitor the status and quality of the cladding process in real time, and make corresponding adjustments and optimizations to ultimately meet the predetermined cladding requirements.

[0094] In summary, the laser cladding system is a highly integrated and automated processing system, and its components work together to achieve efficient cladding processing. By precisely controlling the laser beam, the delivery of metal wires, and the motion parameters of each component, high-quality cladding processing can be performed on workpieces of different materials and shapes, and automated and precise cladding of the surface of the base material can be achieved, thereby improving the wear resistance, corrosion resistance, heat resistance and other properties of the material surface. The cladding layer and the base achieve a dense metallurgical bond, which reliably solves the internal hollowing problem of the clad stainless steel plate and improves the stability and safety of the support structure.

[0095] like Figure 2 As shown, an embodiment of the present invention provides a cladding method of a bridge bearing stainless steel plate intelligent laser cladding system, which specifically includes the following steps:

[0096] S100: Preparation of substrate and cladding materials: Pre-treat the substrate, including cleaning, degreasing, and rust removal, etc., to ensure that the workpiece surface is clean and free of impurities, and select cladding materials that meet the requirements.

[0097] The cladding material is 321 or 316L stainless steel wire, and the wire diameter is φ0.2mm to φ3mm.

[0098] S200: Cladding system parameter setting: Start the intelligent laser cladding system, check whether all components are operating normally, import the product drawings to be clad in the electrical control system, and specify the cladding range and thickness. According to the cladding requirements, adjust the laser power parameters of the laser cladding head and the wire feeding speed of the wire feeding mechanism. The system automatically plans the cladding path according to the imported drawings and cladding requirements.

[0099] The laser power of the laser cladding head can be adjusted to 3-12 kW, and the wire feeding speed of the wire feeding mechanism is between 1-25 m / min.

[0100] S300: Intelligent laser cladding: The six-axis multi-joint robot drives the laser cladding head to move to the starting point of the path, and the wire feeding mechanism starts to feed the wire. At the same time, the laser in the laser cladding head starts to output the laser beam, which irradiates the substrate surface and the cladding material, causing them to melt and mix quickly. The laser tracker monitors the cladding path and the thickness of the cladding layer in real time and transmits it to the electrical control system. The real-time monitored information is compared with the predetermined cladding path and the cladding layer thickness requirements. According to the comparison results, the cladding layer thickness and the cladding path are adjusted in real time to ensure that the cladding process is carried out according to the predetermined requirements and finally meet the predetermined cladding requirements.

[0101] The thickness of the cladding layer is controlled by adjusting the wire feeding speed of the wire feeding mechanism and the moving speed of the laser beam. The thickness of the stainless steel cladding layer is 0.5 mm to 5 mm.

[0102] S400: Finishing and polishing of the cladding layer: After the cladding is completed, the cladding layer is finished to the required thickness by processing equipment (such as CNC milling machines, grinders, etc.), and then polished to the required roughness to meet the use requirements.

[0103] Embodiment 1:

[0104] like Figure 3 The figure shows a schematic diagram of intelligent laser cladding processing of a flat stainless steel plate for a bridge support. The structure includes a steel substrate 1, a stainless steel laser cladding layer 2, and an intelligent laser cladding system 3. The specific steps are as follows:

[0105] S100: placing the cleaned and pre-treated steel substrate 1 flat on a workbench, and using a 321 stainless steel wire with a diameter of φ1 mm as a cladding material;

[0106] S200: Start the intelligent laser cladding system, check whether the six-axis multi-joint robot, laser tracker, laser cladding head, wire feeding mechanism and electrical control system are operating normally, import the product drawings of the bridge support flat stainless steel plate into the electrical control system, specify the cladding range and thickness requirements, adjust the laser power of the laser cladding head to 8kW, the wire feeding speed to 5m / min, and the system automatically plans the cladding path.

[0107] S300: The six-axis multi-joint robot drives the cladding head to the starting point of the path, and the wire feeding mechanism feeds the wire to start reciprocating cladding. The laser tracker monitors the cladding path in real time and transmits it to the control system, making real-time adjustments to the cladding quality and path, and finally completing the plane cladding with a cladding thickness of 2.9 mm.

[0108] S400: After cladding, the cladding surface is finely processed and polished by a CNC milling machine to ensure that the surface roughness of the cladding layer after polishing is Ra≤0.8μm and the thickness of the cladding layer is 2mm, which meets the use requirements.

[0109] Embodiment 2:

[0110] like Figure 4 As shown, this embodiment provides a schematic diagram of intelligent laser cladding processing of convex stainless steel plates of bridge bearings. The structure includes a steel substrate 1, a stainless steel laser cladding layer 2, and an intelligent laser cladding system 3. The specific steps are as follows:

[0111] S100: placing the cleaned and pre-treated steel substrate 1 flat on a workbench, and using a 316L stainless steel wire with a diameter of φ2 mm as a cladding material;

[0112] S200: Start the intelligent laser cladding system, check whether the six-axis multi-joint robot, laser tracker, laser cladding head, wire feeding mechanism and electrical control system are operating normally, import the product drawings and spherical parameters of the bridge bearing spherical stainless steel plate into the electrical control system, specify the cladding range and thickness requirements, and the intelligent laser cladding system 3 automatically plans the optimal spherical cladding path. At the same time, finely adjust the laser power parameters of the laser cladding head to 10kW and the wire feeding speed of the wire feeding mechanism to 6m / min according to the cladding requirements;

[0113] S300: The six-axis multi-joint robot drives the cladding head to the starting point of the path. The wire feeding mechanism feeds the wire and starts cladding from the outside of the spherical surface and clads inward layer by layer. The laser tracker monitors the cladding path in real time and transmits it to the control system. The cladding quality and path are adjusted in real time, and finally the spherical cladding is completed with a cladding thickness of 2.2mm.

[0114] S400: After cladding, the cladding surface is finely processed and polished by a CNC lathe to ensure that the surface roughness of the cladding layer after polishing is Ra≤0.8μm and the thickness of the cladding layer is 1.5mm, which meets the use requirements.

[0115] Embodiment 3:

[0116] like Figure 5 As shown, this embodiment provides a schematic diagram of intelligent laser cladding processing of concave stainless steel plates of bridge bearings, and its processing method is similar to that of convex stainless steel plates of bridge bearings.

[0117] like Figure 6 As shown, the stainless steel plate seismic isolation bearing is manufactured by the above-mentioned bridge bearing stainless steel plate intelligent laser cladding system, including an upper seat plate 4, a spherical crown 5, a middle seat plate 6, a lower seat plate 7, a stainless steel laser cladding layer 2 and a wear-resistant slide plate 8. The upper seat plate 4, the spherical crown 5, the middle seat plate 6, and the lower seat plate 7 are all machined from steel plates or cast steel parts; the stainless steel laser cladding layer 2 is machined from stainless steel wire on the surface of the substrate using an intelligent laser cladding system; the wear-resistant slide plate is made of modified high molecular weight Dacron (HSM) or other polymer slide plate materials. The stainless steel laser cladding structure provided by the present invention ensures that the stainless steel plate of the bridge bearing is completely metallurgically bonded to the substrate, has no risk of hollowing, and has a long service life.

[0118] It is easy for those skilled in the art to understand that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. For example, the bearing structure is not limited to the seismic isolation bearing structure described herein. Any processing of stainless steel sliding pairs using wire laser cladding on the substrate plane, convex spherical surface, and concave spherical surface should be included in the protection scope of the present invention. The present invention uses 321 wire or 316L wire for laser cladding. The protection scope of the present invention is not limited to stainless steel wire. Other iron-based, nickel-based, cobalt-based, copper-based, titanium-based, aluminum-based, and chromium-based wires should be included in the protection scope of the present invention when they are used for the processing of bridge bearing sliding pairs using laser cladding methods. In short, any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An intelligent laser cladding system for bridge bearing stainless steel plates, characterized in that: include: A laser cladding head, used to provide laser energy to melt the cladding material and the substrate; A six-axis multi-joint robot, used for controlling and moving the laser cladding head in multiple directions; The laser tracker uses high-precision sensors and algorithms to automatically identify the cladding range, calculate the optimal cladding path, monitor the position of the laser cladding head and the cladding path in real time, and provide real-time feedback. The algorithm includes an automatic cladding range identification algorithm: using the Canny edge detection algorithm to identify the boundary of the cladding area. The Canny edge detection algorithm mainly includes the following steps: ① Use a high-resolution camera to capture images of the area to be clad, ② Gaussian filtering to reduce noise, ③ calculate gradient amplitude and direction, ④ non-maximum suppression, ⑤ dual threshold detection and edge connection; Among them, the gradient amplitude G and direction θ can be calculated by the following formula: Among them, G x and G y are the gradients of the image in the x and y directions respectively; After determining the boundary of the cladding area, the Otsu's method can be used to automatically determine the optimal threshold T to segment the image into the cladding area and the background area. The goal of Otsu's method is to minimize the intra-class variance, that is, to maximize the inter-class variance. The threshold T can be calculated by the following formula: Among them, ω0(T) and ω1(T) are the probabilities of the background and cladding areas, respectively, and μ0(T) and μ1(T) are the means of the background and cladding areas, respectively; A wire feeding mechanism is used to provide cladding material. The cladding material is cladding wire, and the melting process is gentle and splash-free, thereby achieving high material utilization; As well as the electrical control system, the core part of the entire laser cladding system, it is used to coordinate and control the work of other components to achieve intelligent cladding.

2. According to claim 1, a bridge support stainless steel plate intelligent laser cladding system is characterized in that: The algorithm also includes an algorithm for calculating the optimal cladding path: based on the identified cladding area, a path planning algorithm A* algorithm is used to find the optimal path from the starting point to the end point. The A* algorithm is specifically as follows: Define the heuristic function h(n) and the cost function g(n), the cost function f(n) is: f(n)=g(n)+h(n) Among them, g(n) is the actual cost from the starting node to the current node n, and h(n) is the estimated cost from the current node n to the target node; The heuristic function h(n) is used to estimate the cost from the current node to the target node, which uses the Euclidean distance: Among them, x n , x g are the x-axis coordinates of the current node n and the target node g, n ,y g are the coordinates of the current node n and the target node g on the y-axis, When the target node is found, the path from the start node to the target node is reconstructed by tracing the parent nodes. This process provides the actual route taken by the algorithm to reach the target node, showing the sequence of nodes in the optimal path, and efficiently finding the optimal path.

3. According to claim 2, a bridge support stainless steel plate intelligent laser cladding system is characterized in that: The algorithm also includes a real-time monitoring algorithm for the position of the laser cladding head and the cladding path: the laser tracker obtains the position of the laser cladding head in real time through a high-precision sensor, and the actual position of the laser cladding head is assumed to be (x t ,y t ), the theoretical position on the predetermined path is (x d ,y d ), then the position error (e x , e y ) can be expressed as: e x =x d -x t and y =and d -and t According to the position error, the PID controller is used to correct the position error and adjust the path of the laser cladding head to ensure the accuracy of the cladding path. The output u(t) of the PID controller is: Where, e(t) is the position error, K p , K i , K d are the parameters of the PID controller.

4. According to claim 1, a bridge support stainless steel plate intelligent laser cladding system is characterized in that: The laser cladding head is internally provided with a high-power laser, which can generate a high-energy-density laser beam for melting the cladding material and the substrate to form a cladding layer.

5. According to claim 1, the intelligent laser cladding system for bridge bearing stainless steel plates is characterized in that: The six-axis multi-joint robot has six-degree-of-freedom movement and rotation functions, and drives the laser cladding head to provide precise spatial positioning and motion control during the cladding process.

6. According to claim 1, the intelligent laser cladding system for bridge bearing stainless steel plates is characterized in that: The wire feeding mechanism ensures that the delivery speed and amount of the cladding material match the moving speed of the laser cladding head and the cladding requirements through precise motor control and sensor feedback.

7. According to claim 1, the intelligent laser cladding system for bridge bearing stainless steel plates is characterized in that: The electrical control system is used to coordinate the motion control of various components, reasonably adjust the parameters such as cladding power, cladding path, wire feeding speed according to the cladding requirements, and monitor the state and quality of the cladding process in real time.

8. A cladding method using the intelligent laser cladding system for bridge bearing stainless steel plates according to any one of claims 1 to 7, characterized in that: The specific steps include: S100: Preparation of substrate and cladding materials: pre-treat the substrate and select cladding wire that meets the requirements; S200: Cladding system parameter setting: Start the intelligent laser cladding system, import product drawings, specify the cladding range and thickness, adjust the laser power parameters and wire feeding speed, and automatically plan the cladding path; S300: Intelligent laser cladding: The six-axis multi-joint robot drives the laser cladding head to move to the starting point of the path, the wire feeding mechanism delivers the wire, the laser cladding head outputs the laser beam, and the laser tracker monitors the cladding path and cladding layer thickness in real time and transmits them to the electrical control system, making real-time adjustments to the cladding quality and path, and finally completing the predetermined cladding requirements; S400: Finishing and polishing of cladding layer: Finish the cladding layer to the required thickness, and then polish it to the required roughness to meet the use requirements.

9. The intelligent laser cladding method for bridge bearing stainless steel plate according to claim 8, characterized in that: The cladding wire is a stainless steel wire with a wire diameter between φ0.2 mm and φ3 mm. The wire feeding speed of the wire feeding mechanism is between 1 and 25 m / min. The laser power of the laser cladding head can be adjusted to 3 to 12 kW.

10. The intelligent laser cladding method for bridge bearing stainless steel plate according to claim 8, characterized in that: The thickness of the cladding layer is controlled by adjusting the wire feeding speed of the wire feeding mechanism and the moving speed of the laser beam. The thickness of the stainless steel cladding layer is between 0.5 mm and 5 mm.

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