A real-time virtual quantitative display method for spraying film thickness for spraying robots

Abstract

The present invention discloses a real-time virtual quantitative display method for spray film thickness of a spraying robot, comprising: step 1: establishing a three-dimensional virtual space consistent with the real environment where the spraying robot is located and a virtual spraying model corresponding to the spraying robot; step 2: collecting the operating parameters and environmental parameters of the spraying robot when the spraying robot is performing spraying work, and writing the collected data into a database in real time; step 3: based on the data in the database, the virtual spraying model simulates spraying in the three-dimensional virtual space to obtain the spray film thickness of each point on the workpiece to be sprayed; step 4: according to the spray film thickness of each point on the workpiece to be sprayed, controlling the spray robot to perform supplementary spraying on the workpiece to be sprayed.

Description

Technical Field

[0001] The invention belongs to the field of spraying technology, and in particular relates to a real-time virtual quantitative display method for spraying film thickness for a spraying robot. Background Art

[0002] To ensure the effect and quality of automated spraying, most automated spraying uses mathematical modeling or CFD-based methods to pre-simulate the planned spraying trajectory. However, many uncontrollable factors (temperature, humidity, paint type, etc.) in the actual spraying process often affect the uniformity of the spraying, which deviates greatly from the pre-simulation. At the same time, since the film thickness cannot be detected when the paint is not dry, it is impossible to measure the film thickness in real time during the spraying process to adjust the trajectory and re-spray. Summary of the invention

[0003] Purpose of the invention: In order to solve the problem that the film thickness cannot be measured in real time during the spraying process, the present invention proposes a real-time virtual quantitative display method of the spraying film thickness for a spraying robot.

[0004] Technical solution: A real-time virtual quantitative display method for spray film thickness for a spray robot, comprising the following steps:

[0005] Step 1: Establish a three-dimensional virtual space that is consistent with the real environment where the spraying robot is located and a virtual spraying model corresponding to the spraying robot;

[0006] Step 2: Collect the operating parameters and environmental parameters of the spray robot when the spray robot is spraying, and write the collected data into the database in real time;

[0007] Step 3: Based on the data in the database, the virtual spraying model simulates spraying in a three-dimensional virtual space to obtain the spraying film thickness at each point on the workpiece to be sprayed;

[0008] Step 4: According to the spray film thickness at each point on the workpiece to be sprayed, control the spraying robot to perform additional spraying on the workpiece to be sprayed.

[0009] Furthermore, the operating parameters of the spraying robot include position information of each joint, speed information of each joint and switch information of the spraying robot; and the environmental parameters include environmental temperature data and environmental humidity data.

[0010] Furthermore, in step 3, the spray film thickness at each point on the workpiece to be sprayed is obtained, and the specific operations include:

[0011] In the three-dimensional virtual space, define the workpiece to be sprayed;

[0012] Using a cube, constructing a new network of the workpiece to be sprayed according to the intersection relationship between each face of the cube and the workpiece to be sprayed;

[0013] The spray paint is rendered on this new network according to the spray coating growth rate model;

[0014] The thickness of the sprayed film at any point on the new grid is represented by a color gradient.

[0015] Furthermore, the spray coating growth rate model is expressed as:

[0016]

[0017] Where D(x) is the spray film thickness, a is the major axis radius of the ellipse in the spray area, b is the minor axis radius of the spray area, and H max is the thickest value of spraying, and v is the moving speed.

[0018] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0019] 1. By reading the spray robot parameters in real time and establishing a connection with the 3D engine through the database, the 3D engine can simulate the movement of the spray robot in real time;

[0020] 2. Use the particle system of Unity 3D development engine or other 3D development engine to simulate the spraying effect. Since the particles of the Particle System are different from Game Objects and are built-in particle systems of the system, the simulated spraying effect does not need to occupy too much CPU and GPU when running, allowing the system to run smoothly. If you use a real GameObject, when the particles reach 1000 or more, the system will be seriously stuck and the simulated spraying effect will be poor;

[0021] 3. Through the pre-given coating growth rate mathematical model, the 3D development engine system can virtually and quantitatively display the spray film thickness and uniformity;

[0022] 4. Solve the problem of not being able to directly render the mesh of the sprayed object by dynamically building the mesh;

[0023] 5. The film thickness is characterized by color gradient. The distribution of spray film thickness and spray uniformity can be intuitively seen according to different color gradients;

[0024] 6. Through script compilation, you can click the workpiece position with the mouse to quantitatively display the spray film thickness at that point;

[0025] 7. Through real-time spraying effect simulation and quantitative display of film thickness, the limitations of pre-simulation spraying based on CFD method are effectively avoided, and real-time trajectory adjustment and re-spraying are convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the virtual spraying process of the present invention;

[0027] Figure 2 It is a schematic diagram of the spraying film thickness process of the present invention. DETAILED DESCRIPTION

[0028] The present invention is further described below with reference to the accompanying drawings and embodiments.

[0029] like Figure 1 As shown, a real-time virtual quantitative display method of spray film thickness for a spray robot of the present invention mainly comprises the following steps:

[0030] Step 1: In the Unity 3D development engine or other 3D development engines, establish a virtual space that is consistent with the real environment where the spraying robot is located and a virtual spraying model corresponding to the spraying robot;

[0031] Step 2: When the spray robot is working, collect the operating parameters of the spray robot, that is, the angle of each joint of the spray robot, the switch signal of the spray robot, the current environmental parameters of the spray robot, etc., and write the collected operating parameters into the database in real time; the specific implementation steps are: read the temperature data from the temperature sensor, the humidity data from the humidity sensor, the PLC variables (the position information of each joint of the spray robot, the speed information of each joint of the spray robot, the switch information of the spray robot) and other parameters of the spray robot through OPC UA or other communication methods; write the read data into the database in real time;

[0032] Step 3: The Unity development engine or other development engines read the data in the database in real time, drive the movement of the virtual spray model through a script (C# or other), and realize the simulation display of the spray effect through the particle system (Particle System) of the Unity 3D development engine or other three-dimensional development engine. In the simulation display of the spray effect of the present invention, the spray film thickness is displayed in real time through the spray film thickness and uniformity characterization method, which is convenient for re-coating and visual display of spray uniformity. Specifically comprising the following steps:

[0033] In the 3D engine, define the workpiece to be sprayed, use a cube to intercept the workpiece to be sprayed, construct a new grid of the workpiece to be sprayed according to the intersection relationship between each face of the cube and the workpiece to be sprayed, and render the paint on the new grid according to the coating growth rate mathematical model. When rendering, the film thickness is represented by color gradient, and the color depth is divided into 1024 gradients. The spray film thickness and spray uniformity can be intuitively seen according to different color gradients. In the 3D engine, write a script, click the mouse on a certain point of the workpiece to be sprayed, read the color gradient of the point, and quantitatively display the spray film thickness at the point.

[0034] The coating growth rate mathematical model of the present invention is used to calculate the spray film thickness and reflect the film thickness when the real spray robot is spraying. The coating growth rate mathematical model is established according to the elliptical double β distribution of the finite range model in the spray coating growth rate model. The elliptical double β mathematical model satisfies the x-direction coating growth rate as the β distribution model, and the y-direction growth rate is also satisfied, and the value of β remains unchanged on any cross section in the same direction. Try to give β1=2, β2=4, and get the following mathematical model expression:

[0035]

[0036] Where a is the radius of the major axis of the ellipse, b is the radius of the minor axis, and H max is the thickest value of spraying on the x-direction section, and v is the moving speed.

[0037] Based on this mathematical model, when the spray gun pressure, flow rate, cone angle and nozzle distance remain unchanged, parameters a and b are constant, and the spraying speed is v, H max is a constant value and is inversely proportional to the moving speed. a, b, H max All are easy to measure. a, b, H max After the value of is determined, the distance x from the center can correspond to the unique spray film thickness. Tests are conducted using commonly used spray gun pressure, flow rate, cone angle and nozzle distance to measure a, b, H max , obtain the mathematical model and store it in the database to facilitate real-time calling by the 3D development engine.

Claims

1. A real-time virtual quantitative display method for spray film thickness for a spray robot, characterized in that: The following steps are involved: Step 1: Establish a three-dimensional virtual space that is consistent with the real environment where the spraying robot is located and a virtual spraying model corresponding to the spraying robot; Step 2: Collect the operating parameters and environmental parameters of the spray robot when the spray robot is spraying, and write the collected data into the database in real time; Step 3: Based on the data in the database, the virtual spraying model simulates spraying in a three-dimensional virtual space to obtain the spraying film thickness at each point on the workpiece to be sprayed; Step 4: According to the spray film thickness at each point on the workpiece to be sprayed, control the spraying robot to perform additional spraying on the workpiece to be sprayed; The spray robot operation parameters include the position information of each joint, the speed information of each joint and the switch information of the spray robot; the environmental parameters include the environmental temperature data and the environmental humidity data; In step 3, the spray film thickness at each point on the workpiece to be sprayed is obtained, and the specific operations include: In the three-dimensional virtual space, define the workpiece to be sprayed; Using a cube, constructing a new network of the workpiece to be sprayed according to the intersection relationship between each face of the cube and the workpiece to be sprayed; The spray paint is rendered on this new network according to the spray coating growth rate model; The thickness of the sprayed film at any point on the new network is characterized by a color gradient; The spray coating growth rate model is expressed as: （1） in, is the spray film thickness, a is the radius of the major axis of the ellipse in the spraying area, b is the minor axis radius of the ellipse in the spraying area, The thickest value for spraying. v It is the movement speed.

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