Intelligent automatic welding robots can be classified according to their functions, such as cutting, welding, handling, spraying back, palletizing, etc., and also, in answer to the question, their arm span, load, etc.

What is a welding robot?
Robotic welding is the use of mechanised programmable tools (robots) to fully automate the welding process by performing the welding and handling of parts.

Processes such as gas shielded metal arc welding, although often automated, are not equivalent to robotic welding as the operator sometimes prepares the material to be welded. Robotic welding is often used for resistance spot welding and arc welding in high production applications (e.g. in the automotive industry).

With the development of electronics, computer technology, numerical control and robotics, automatic welding robots, which have been used in production since the 1960s, have become increasingly sophisticated and have the following main advantages:

(1) Stabilisation and improvement of the quality of welding, which can be reflected in the form of numerical values.
(2) Increased labour productivity.
(3) Improved labour intensity for workers working in hazardous environments.
(4) Reduced requirements for workers' operating skills.
(5) shorten the preparation cycle of product changeover and reduce the corresponding equipment investment.

As a result, it has been widely used in various industries.

Features:
Spot welding is not very demanding for welding robots. This is because spot welding only requires spot control, and there are no strict requirements as far as the trajectory of the welding tongs moving between spots, which is why robots could only be used for spot welding early on. A robot for spot welding must not only have sufficient load capacity, but also be fast, smooth and accurate in its positioning when moving from point to point, in order to reduce the time spent on shifting and improve efficiency. How much load capacity a spot welding robot needs to have depends on the type of welding clamp used. For the use of a welding clamp separate from the transformer, a robot with a load of 30 to 45 kg is sufficient. However, on the one hand, this type of welding clamp has a long secondary cable, which results in high power losses and is not conducive to the robot reaching inside the workpiece to weld; on the other hand, the cable keeps swinging with the robot's movement and the cable is damaged more quickly. Therefore, there is a gradual increase in the use of one-piece welding tongs. This type of welding clamp, together with the transformer, has a mass of around 70 kg. Considering that the robot should have sufficient load capacity to deliver the welding pliers to the space position with a large acceleration, the heavy robot with a load of 100-150kg is generally used. In order to adapt to the requirements of continuous spot welding, the weld clamp can be moved quickly over short distances. The new heavy-duty robots have added the ability to complete a 50mm displacement in 0.3s. This places higher demands on the performance of the motor, the speed of the microcomputer and the algorithm.

Structural design:
As the designed welding robot works in a quasi-flat, narrow space environment, in order to ensure that the robot can follow the weld seam and weld automatically based on the deviation information from the arc sensor, it is required that the designed robot should be compact, flexible in movement and stable in operation. In this paper, a small mobile welding robot is developed for narrow spaces. The robot mechanism is divided into three parts: the wheeled mobile platform, the torch adjustment mechanism and the arc sensor, based on the movement characteristics of the robot structures and using modular design methods. The wheeled mobile platform, due to its large inertia and slow response, is mainly responsible for coarse tracking of the weld seam, the torch adjustment mechanism for seam tracking and the arc sensor for real-time identification of the weld seam deviation. In addition, the robot controller and motor drive are integrated into the robot mobile platform, making it smaller in size. A fully enclosed structure is also used to reduce the impact of dust on moving parts in harsh welding environments, increasing the reliability of the system.