CN115178833B - Robot multilayer multi-channel welding manufacturing system and control method and system thereof - Google Patents

Abstract

The present invention provides a robot multi-layer and multi-pass welding manufacturing system and a control method and system thereof, comprising: a welding module, a robot and its control module, a welding parameter measurement module and a host computer control module; the welding module comprises a welding power source, a welding torch, an argon gas cylinder and a cooling water tank; the welding power source, the argon gas cylinder and the cooling water tank are respectively connected to the welding torch; the welding torch is fixed on the robot; the robot and its control module comprise a six-axis industrial robot body and a controller thereof, which receive instructions from a host computer to adjust the spatial position and posture of the welding torch, and send the spatial position information of the welding torch to the host computer in real time; the welding parameter measurement system comprises an arc voltage sensor and a current sensor, which respectively send the measured voltage and current information to the host computer in real time; the host computer control module receives the spatial position information and the voltage and current information of the welding torch.

Description

Robotic multi-layer multi-pass welding manufacturing system and control method and system thereof

Technical Field

The present invention relates to the field of mechanical processing and manufacturing technology, and in particular to a robot multi-layer multi-pass welding manufacturing system and a control method and system thereof.

Background Art

In actual engineering production, multi-layer and multi-pass welding processes are generally required for thicker components. For more complex workpieces with non-fixed weld widths and asymmetric dimensions on both sides of the groove, when using robots for welding, it is generally necessary to use manual teaching for repeated verification, or to use optical measuring instruments to measure the weld size. The former increases the workload and reduces work efficiency, while the latter greatly increases the system cost.

Patent document WO2021114692A1 (application number: PCT/CN2020/106399) discloses a welding control method and a welding control system, in which the welding control method obtains parameter information of the welding groove, and then calls the welding control parameters corresponding to the parameter information according to the acquired parameter information and generates a welding control program, and finally controls the welding robot to perform welding on the welding groove through the welding control parameters and the welding control program.

The present invention provides a robot multi-layer multi-pass welding manufacturing system and a control method, so as to improve the manufacturing efficiency and manufacturing accuracy of the multi-layer multi-pass welding process of thick components and reduce the equipment cost.

Summary of the invention

In view of the defects in the prior art, the object of the present invention is to provide a robot multi-layer and multi-pass welding manufacturing system and a control method and system thereof.

A robot multi-layer multi-pass welding manufacturing system provided according to the present invention comprises: a welding module, a robot and its control module, a welding parameter measurement module and a host computer control module;

The welding module includes a welding power source, a welding torch, an argon gas cylinder and a cooling water tank; the welding power source, the argon gas cylinder and the cooling water tank are respectively connected to the welding torch; the welding torch is fixed on the robot;

The robot and its control module include a six-axis industrial robot body and its controller, which receive instructions from a host computer to adjust the spatial position and posture of the welding torch, and send the spatial position information of the welding torch to the host computer in real time;

The welding parameter measurement system includes an arc voltage sensor and a current sensor, which respectively send the measured voltage and current information to the host computer in real time;

The host computer control module receives the spatial position information and voltage and current information of the welding torch.

Preferably, in the welding module, the welding power source, argon gas cylinder and cooling water tank are connected to the welding torch through electricity, water and gas pipelines respectively, and the welding torch is fixed on the sixth axis of the industrial robot.

According to a control method of a robot multi-layer multi-pass welding manufacturing system provided by the present invention, the robot multi-layer multi-pass welding manufacturing system described above is used to perform:

Step S1: Controlling the welding torch to move along a preset trajectory through the robot;

Step S2: The spatial position information of the welding torch is sent to the host computer in real time through the robot controller; at the same time, the arc voltage and current sensors transmit the welding parameter measurement data to the host computer in real time;

Step S3: Obtain a motion trajectory correction value according to the arc voltage obtained in real time by the host computer, and obtain the actual welding trajectory based on the motion trajectory correction value.

Preferably, the step S1 adopts: determining the welding starting point position, the robot moves the welding torch to the welding starting point and starts the arc using a current that meets preset requirements.

Preferably, the step S3 adopts: using the linear relationship between arc voltage and arc length to obtain the correction value.

Preferably, when the current measured by the current sensor exceeds a preset value, the robot multi-layer and multi-pass welding manufacturing system is shut down.

According to a control system of a robot multi-layer multi-pass welding manufacturing system provided by the present invention, the robot multi-layer multi-pass welding manufacturing system described above is used to perform:

Module M1: The robot controls the welding torch to move along a preset trajectory;

Module M2: The robot controller sends the spatial position information of the welding torch to the host computer in real time; at the same time, the arc voltage and current sensors transmit the welding parameter measurement data to the host computer in real time;

Module M3: Obtain the motion trajectory correction value according to the arc voltage obtained in real time by the host computer, and obtain the actual welding trajectory based on the motion trajectory correction value.

Preferably, the module M1 adopts: determining the welding starting point position, the robot moves the welding torch to the welding starting point and then uses a current that meets preset requirements to start the arc.

Preferably, the module M3 adopts: using the linear relationship between arc voltage and arc length to obtain the correction value.

Preferably, when the current measured by the current sensor exceeds a preset value, the robot multi-layer and multi-pass welding manufacturing system is shut down.

Compared with the prior art, the present invention has the following beneficial effects:

The present invention provides a robot multi-layer multi-pass welding manufacturing system and a control method, so as to improve the manufacturing efficiency and manufacturing accuracy of the multi-layer multi-pass welding process of thick components and reduce the equipment cost.

Without adding additional expensive optical measuring equipment, the existing equipment can be used to measure and correct the shape of the sample groove by taking advantage of the proportional relationship between arc voltage and distance, thus achieving high-precision welding of medium and thick plates/thick plates with multiple layers and multiple passes at almost no additional cost.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

Figure 1 is a schematic diagram of the welding system.

Figure 2 is a schematic diagram of the control system.

FIG. 3 is an example diagram of a substrate groove structure.

FIG4 is a schematic diagram of the substrate structure and trajectory.

Figure 5 is a trajectory example diagram.

DETAILED DESCRIPTION

The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

Example 1

The present invention provides a robot multi-layer and multi-pass welding manufacturing system, as shown in FIG1 , which mainly includes a welding system, a robot and its control system, a welding parameter measurement system and a host computer control system.

The welding system mainly includes a welding power supply, a welding torch, an argon gas cylinder and a cooling water tank. The power supply, argon gas cylinder and water tank are connected to the welding torch through electricity, water and gas pipelines respectively. The welding torch is fixed on the sixth axis of the industrial robot.

The robot and its control system mainly include a six-axis industrial robot body and its controller, which can receive instructions from a host computer to adjust the spatial position and posture of the welding torch and send the position information of the welding torch to the host computer in real time.

The welding parameter measurement system mainly includes arc voltage sensor and current sensor, which can send voltage and current information to the host computer system in real time.

As shown in FIG2 , the host control system can receive the spatial position information of the welding torch from the robot controller, and the arc voltage and circuit information from the measurement system.

The present invention also provides a robot multi-layer multi-pass welding manufacturing system method, comprising the following steps:

Determine the welding starting point in the middle of the weld by manual teaching;

After the robot moves the welding torch to the welding starting point, it starts an arc with a small electric arc. The current is set to about 15A and moves along a pre-set path. In this embodiment, the robot controls the welding torch to move along a straight reciprocating trajectory. The spacing between the trajectories is set to L. At the same time, the robot controller continuously transmits the spatial position information of the welding torch to the host computer, and the arc voltage and current sensors continuously transmit the welding parameter measurement data to the host computer.

The present invention is applied to thick plates that need to be grooved. The process is multi-layer and multi-pass. The shape and size of the groove are always changing due to machining errors, thermal deformation caused by the previous welds, and other factors. The size needs to be corrected to eliminate the error. At this time, a dedicated optical measuring instrument is generally required, or manual correction is required. The present invention uses existing welding equipment, uses the linear relationship between arc voltage and arc length, first uses a small current to start the arc and moves along a predetermined trajectory, records the spatial position information, and generates a final trajectory after correcting the predetermined trajectory based on the correction value obtained by the arc voltage.

As shown in Figure 3-5, the control method of this patent is explained by taking the starting point of the trajectory as an example:

When the welding torch moves from the starting point in the middle of the weld to the edge of the groove, the arc length and arc pressure continue to decrease. When the welding torch reaches point P0, the arc pressure decreases to the threshold value U. The robot controller records the spatial position of the welding torch at this time and sends it to the host computer, which is the coordinate of the trajectory edge point P0. The welding torch is then controlled to move in the welding direction. When the arc pressure continues to decrease, it shifts toward the center of the weld. When the arc pressure continues to increase, it shifts toward the edge of the weld. The arc pressure is kept stable during the movement so that the motion trajectory and the groove edge basically coincide. When the movement distance along the welding direction is L, it reaches point P1. Then the welding torch moves in the direction perpendicular to the welding direction. The arc pressure first increases and then decreases. When the welding torch reaches point P3, the arc pressure decreases to the threshold value U. The robot controller records the spatial position of the welding torch at this time and sends it to the host computer, which is the coordinate of the trajectory edge point P3. This process is repeated to obtain the spatial position coordinates of subsequent path points.

The actual welding trajectory is: welding starting point——P1——P4——P7 points.

Those skilled in the art know that, in addition to implementing the system, device and its various modules provided by the present invention in a purely computer-readable program code, it is entirely possible to implement the same program in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers and embedded microcontrollers by logically programming the method steps. Therefore, the system, device and its various modules provided by the present invention can be considered as a hardware component, and the modules included therein for implementing various programs can also be considered as structures within the hardware component; the modules for implementing various functions can also be considered as both software programs for implementing the method and structures within the hardware component.

The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims (2)

1. A control method for a robot multi-layer multi-pass welding manufacturing system, characterized in that the robot multi-layer multi-pass welding manufacturing system comprises: a welding module, a robot and its control module, a welding parameter measurement module and a host computer control module; The welding module includes a welding power source, a welding torch, an argon gas cylinder and a cooling water tank; the welding power source, the argon gas cylinder and the cooling water tank are respectively connected to the welding torch; the welding torch is fixed on the robot; The robot and its control module include a six-axis industrial robot body and its controller, which receive instructions from a host computer to adjust the spatial position and posture of the welding torch, and send the spatial position information of the welding torch to the host computer in real time; The welding parameter measurement module includes an arc voltage sensor and a current sensor, which respectively send the measured voltage and current information to the host computer in real time; The host computer control module receives the spatial position information and voltage and current information of the welding torch; In the welding module, the welding power source, argon gas cylinder and cooling water tank are connected to the welding torch through electricity, water and gas pipelines respectively, and the welding torch is fixed on the sixth axis of the industrial robot; Step S1: Controlling the welding torch to move along a preset trajectory through the robot; Step S2: The spatial position information of the welding torch is sent to the host computer in real time through the robot controller; at the same time, the arc voltage and current sensors transmit the welding parameter measurement data to the host computer in real time; Step S3: obtaining a motion trajectory correction value according to the arc voltage obtained in real time by the host computer, and obtaining an actual welding trajectory based on the motion trajectory correction value; Specifically: When the welding torch moves from the starting point in the middle of the weld to the edge of the groove, the arc length and arc pressure continue to decrease. When the welding torch reaches point P0, the arc pressure is reduced to the threshold value U. The robot controller records the spatial position of the welding torch at this time and sends it to the host computer. Here is the coordinate of the edge point P0 of the trajectory. Then the welding torch is controlled to move in the welding direction. When the arc pressure continues to decrease, it shifts to the center of the weld. When the arc pressure continues to increase, it shifts to the edge of the weld. The arc pressure is kept stable during the movement process so that the motion trajectory basically coincides with the edge of the groove. When the movement distance along the welding direction is L, it reaches point P1, and then the welding torch Moving in the vertical welding direction, the arc pressure increases first and then decreases. When the welding torch reaches point P3, the arc pressure decreases to the threshold value U. The robot controller records the spatial position of the welding torch at this time and sends it to the host computer, which is the coordinate of the track edge point P3. Then the welding torch is controlled to move in the welding direction. When the arc pressure continues to decrease, it shifts to the center of the weld. When the arc pressure continues to increase, it shifts to the edge of the weld. The arc pressure is kept stable during the movement process so that the motion trajectory and the groove edge basically coincide. When the moving distance along the welding direction is L, it reaches point P4. Thereafter, this process is repeated to obtain the spatial position coordinates of subsequent path points. The actual welding trajectory is: welding starting point - P1 - P4 point; The step S1 comprises: determining the welding starting point position, and the robot moves the welding torch to the welding starting point and uses a current that meets the preset requirements to start the arc; The step S3 adopts: using the linear relationship between arc voltage and arc length to obtain a correction value; When the current measured by the current sensor exceeds a preset value, the robot multi-layer and multi-pass welding manufacturing system is shut down. 2. A control system for a robot multi-layer multi-pass welding manufacturing system, characterized in that the robot multi-layer multi-pass welding manufacturing system comprises: a welding module, a robot and its control module, a welding parameter measurement module and a host computer control module; The welding module includes a welding power source, a welding torch, an argon gas cylinder and a cooling water tank; the welding power source, the argon gas cylinder and the cooling water tank are respectively connected to the welding torch; the welding torch is fixed on the robot; The robot and its control module include a six-axis industrial robot body and its controller, which receive instructions from a host computer to adjust the spatial position and posture of the welding torch, and send the spatial position information of the welding torch to the host computer in real time; The welding parameter measurement module includes an arc voltage sensor and a current sensor, which respectively send the measured voltage and current information to the host computer in real time; The host computer control module receives the spatial position information and voltage and current information of the welding torch; In the welding module, the welding power source, argon gas cylinder and cooling water tank are connected to the welding torch through electricity, water and gas pipelines respectively, and the welding torch is fixed on the sixth axis of the industrial robot; Module M1: The robot controls the welding torch to move along a preset trajectory; Module M2: The robot controller sends the spatial position information of the welding torch to the host computer in real time; at the same time, the arc voltage and current sensors transmit the welding parameter measurement data to the host computer in real time; Module M3: obtains the motion trajectory correction value according to the arc voltage obtained in real time by the host computer, and obtains the actual welding trajectory based on the motion trajectory correction value; The module M1 adopts: determining the welding starting point position, the robot moves the welding torch to the welding starting point and uses the current that meets the preset requirements to start the arc; The module M3 adopts: using the linear relationship between arc voltage and arc length to obtain a correction value; When the current measured by the current sensor exceeds a preset value, the robot multi-layer and multi-pass welding manufacturing system is shut down.