What is Robot Welding ? | Robotic Welding
Robot Welding utilizes mechanized programmable tools (robots) that facilitate complete automation of a welding process through both conduction of the weld and handling the component. Robot welding finds its extensive application in resistance spot welding and arc welding, pertaining to high production units such as the automotive industry. Not every automated welding process necessarily conforms to Robot Welding because often they have human intervention involved. Many automated welding processes require a human to prepare the materials that are to be welded, for example- the gas arc welding process.
Robotic Welding Machine | Welding Robot in Automotive Industry
Robot Welding is one of the very recent applications of robotics as it didn’t start until the 1980s. It took off with its use in spot welding and has already established its command over almost twenty percent of industrial robotic applications. The two important components of a robotic system that are utilized in robot welding are the manipulator, which is the mechanical unit, and the controller, which is also called the brain of the robot. We will learn about different types of robot welding and the way they utilize the automated mechanized tools in the further sections.
The process of Robot Welding uses either pre-programmed position coordinates or machine vision in its guidance system. The utilization of these mechanized tools through Robot Welding introduces better accuracy, repeatability, and throughput as compared to the traditional pieces of equipment.
How does Robot Welding work?
Robots are used in any process with the aim of making amendments to accommodate automation. Similarly, Robot Welding utilizes many tools that are absent in its manual equivalent. It is important to know that programming used by people is different than how machines are programmed for Robot Welding.
There are two major versions of Robot Welding based on configuration and design. For rectilinear types, the robot’s arm can move in three dimensions, while articulating versions can move through more planes. The filler wire is delivered to the robot by a wire feeder as needed for a welding job. Metal is melted by a high-heat torch, and the molten metal is placed at the end of the arm, followed by the welding process. Robot Welding is advantageous over traditional manual welding because the welding process takes place in an enclosed area. Thus, it substitutes human laborers at temperatures of thousands of degrees and keeps them safe.
Experts with certification from the American Welding Society or AWS are still required to stay in close proximity of the machines in order to avoid any errors occurring during the course of action because machines are easily subject to malfunctioning. The American Welding Society certifies both manual welders as well as Robot Welding arm operators.
Robotic Welding Process | Robotic welding Systems
A teach pendant is used by the operators to configure the controller. This software creates new programs, pushes the arm, and modifies the operation parameters. The operator presses the buttons on the service box to begin welding. The robotic arm’s tool heats up to melt metal and tie the parts together. A wire feeder supplies more metal wire to the arm and torch as required. When it’s time to solder the next part, the arm pushes the torch to the cleaner to clear any metal splatters from the arm that would otherwise solidify in place.
Arc welding-specific robots are smaller and less costly. They have recently been produced by a number of robot manufacturers. The selling of robotic welding systems has improved as a result of the lower necessary capital expenditure. Another recent advancement in welding robotics is the advent of seven-axis robots, which have an extra axis in the lower arm to provide more flexibility with the consumption of low space areas.
Gantry welding Robot
The typical configurations of an arc welding robot are summarized below:
|Velocity||Up to 5 m/s|
|Acceleration||Up to 25 m/s2|
|Repeatability||Up to 0.05mm|
|Communications||Profibus, DeviceNet, CANopen, Ethernet/IP, and serial channels|
|I/O Capabilities||Digital/analog IOs|
Sensors for robotic arc welding applications come in a variety of shapes and sizes. The sensors are categorized in two groups based on their functions: mechanism and geometrical. The mechanism is about determining the process stability by measuring the process parameters of the process such as arc voltage, current, wire feed-speed, and torch spin etc. The geometrical one is catagorized for weld-searching, seam-tracking, and real-time adaptive welding process and measureent of weld joint-geometrical parameters (e.g., distance sizes, weld size changes, divergence from the nominal direction, and orientation changes).
Industrial Welding Robots | Welding Robots in Automotive Industry | Car Welding Robot
Typical sensors for robot arc welding
Robotic Welding Cell
Robotic Welding Turntable
Types of Welding Robot
Robot Welding is a means of automating the procedure, resulting in increased accuracy, reduced waste, and faster production. There are mainly seven types of welding processes that have been briefly discussed below:
Robotic Arc Welding
- Intense heat is produced between an electrode and a metal base.
- A temperature of 6500 degrees Fahrenheit approximately is produced to meet and intermix the above two parts.
- After cooling, the metal joint solidifies into a stable connection.
- Ideal for a high volume of conjoined metals with increased accuracy.
Robotic Spot Welding
- Ideal for joining metals that resist current.
- Usually required for joining sheet metal frames in an automobile body.
- It is a variation of resistance welding.
Robotic Resistance Welding
- Current is passed between the metal pieces to be joined to create a pool of heat.
- Ideal for economic robot welding requirement.
- Best for heat-treating projects.
Robotic TIG Welding
- Ideal for scenarios requiring a high level of precision.
- This also recognized as “GTAW – Gas tungsten arc welding ”.
- An electric arc is formed inbetween tungsten electrode and the metal.
Robotic MIG Welding
- High deposition rate process that is fast and straightforward.
- Involves continuous feeding of a wire toward the heated weld tip that melts the wire allowing a larger surface area for molten metal dripping.
- Ideal where simplicity and speed are desirable.
Robotic Laser Welding | Robot Laser Welding machine system
- Laser light is delivered via a fiber optic cable thru a robotic cutting-head to joint the pieces.
- Ideal for hard-to-reach weld locations.
- Often used in high volume utilization that requires accuracy.
- Majorly found in the automotive parts, jewelry industries, biomedical applications, and their precise applications.
Robotic Plasma Welding
- Extremely high temperatures are produced by passing ionized gases through a copper nozzle.
- Provides flexibility through better adjustment of velocity and temperature.
Automatic Pneumatic Welding Robot
- This is good for sheet-metal applications.
- Less time is required in this process.
Welding Robot Arm | Equipment Design
Whether the system is for welding or other applications, the robot is just one component of a robot-based automation system. Several components and functions are common to all systems, irrespective of what the application is. Some of the common components found in all systems are-
- Controls, Communication, and Operator Interface
- Pneumatics, Sensors, and Electrical Components
- Safety Systems
- Peripheral Equipment
- Cable and Its Management
- The Robot
How to program a Robotic Welder?
Robot Welding programming
Robot Welding programming is very different than how a normal scientist programs a code on a computer. Because of the time it takes to configure a shift in product lines; robotic welding has been limited to high-volume applications until now. Also, for programmers, setting up a robot welder needs extensive programming experience, and procedures are not intuitive. The top five robotic welding programming challenges are listed below:
- Robot computer control systems differ from one manufacturer to the next and from one model to another, and hence it is not an intuitive way of teaching the robot. The control systems are so versatile that while a teach pendant can be used with a joystick, arrows are used to shift the robot welder around.
- Programming a welding robot requires indigenous aligning to each joint and piece of the arm while considering changes in arc and joint-angle.
- The speed for each coordinated movement needs specification of an appropriate acceleration and deceleration of each joint.
- Further program design must be learned, therefore robots may capable to use sensor as I/P and O/P as a binary signal to choose robotic programming and able to perform specific tasks.
- By trial and error, one can gain experience and finally master the programming of a robot welder in some years.
Why is Robotic Welding Important ?
Robot Welding Advantages
- Robots do not require time-offs or rejuvenation breaks as human beings do. They do not require to shut down often in order to generate energy for work. Thus robot welding can operate for longer hours at greater speeds and, therefore, surpasses the kind of output that human labor produces.
- Robot welding occurs in an enclosed area that keeps human labor at bay. Thus, human beings do not require to stay in contact with the high temperatures and the dramatic arc glare of the welding process, which increases their safety in the work environment to a greater deal. Injuries and damaged equipment, on the other hand, can put a company into a huge loss.
- Robot welding works ina programmed manner, and thus, it exhibits a high amount of repeatability and also increased accuracy in the output. It diminishes every possible chance of human error throughout the course of action.
- High-level precision allows the robot to generate less kerf, and the number of pieces getting damaged during the process also reduces to a large extent. This also allows minimum human intervention, and companies can save money by hiring lesser employees.
Robotic Welding Issues and Challenges
Robot Welding Disadvantages
Although robotic welding is beneficial, it does have certain disadvantages that could overshadow the benefits in some circumstances.
- If you use a firm that uses robotic welders, the shipping costs are expected to be smaller. Although if you wanted to invest in the equipment and skilled operators yourself though, you would almost certainly lose money. Individual businesses that may not have specialized welding facilities could not be able to justify the high sales price of robotic welders.
- The advantage of robots behaving more reliably than humans has a drawback. Humans have the ability to respond to unusual circumstances in a way that robots do not. When a robotic welder requires a modification, the operator must halt the operation and reprogram the machine. This lengthens the time taken for more ambitious projects.
- The time it takes to configure the robotic arm could be longer than the welding process for smaller projects. A human welder could complete the process quicker on smaller tasks, but this depends on the project size and the operator’s programming speed.
- Regardless of the adaptive design of human actions, robotics cannot make autonomous disciplinary decisions on their own and must be augmented by the use of sensors and a functional control scheme.
- Owing to space limitations, robotic welding is difficult to do in certain places such as pressure vessels, internal tanks, and ship bodies.
Frequently Asked Questions (FAQs)
What is polarity in welding?
Welding current is a topic that is most commonly heard in a welding class. The electrodes in welding machines are usually labeled AC or DC, which determines the polarity of the welding current. Just like voltage induction due to magnetic flux in a transformer has two poles, the electrical circuit that is created upon turning on the welding machine also has two poles- the positive pole and the negative pole.
The choice of polarity determines the quality and strength of the weld. If the chosen polarity is feasible, it can cause a lot of spatter and damage the metal through wrong penetration. The electrode-negative polarity is termed as straight polarity, whereas the electrode-positive is termed as reverse polarity.
Deeper penetration can be achieved by reverse polarity. On the other hand, a faster deposition rate and fast melt-off can be achieved by straight polarity.
Do you need to be a welder to run an automated welder?
Manual welding vs Robot welding
Welding, although being a manual job, requires a high level of education and skill. This is where Robot Welding comes to the rescue and diminishes human errors to quite an extent. Lesser mistakes cause lesser damage and thus lesser financial loss to the company.
Automated welding has come a long way, and it’s a lot easier to practice now than it used to be. Since the robot handles a large portion of the ability needed for manual welding, workers with no welding experience will easily learn to operate robotic welding cells.
What is welding robot seam tracker system ?
Let us first understand what seam tracking is. Seam tracking, also known as joint tracking, entails tracking in real-time right before the weld is deposited. This enables not only robot or system trajectory changes but also adaptive regulation such as voltage, wire feed, or travel speed modifications to alter weld bead shape.
Welding torch control methods in traditional semi-automated welding processes require manual adjustment of the welding torch, fixed at a distance on the workpiece. This process works well for short durations and provides higher geometric similarity. However, there are also situations where manually tuning the welding torch is either impossible or becomes a boring chore for the operator.
This is why many manufacturers are turning the producers to Weld Seam Tracking devices to specifically monitor the torch to workpiece relationship during welding, reducing operator feedback and increasing weld efficiency and output volume.