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5 ways to take advantage of robotic simulation

Simulation software can be used to validate a robot, especially when the positions are difficult to reach, there are obstacles, robots come almost within contact of each other, there are positioners involved, and the workspace is tight. KUKA Robotics

Industrial robots are flooding the world’s manufacturing facilities with more than 4 million robots set to be in operation in 2022, according to the International Federation of Robotics. As an increasing number of industrial sectors look to upgrade processes to include smart factory automation, it is important to ensure that the project itself is successful.

For shops looking to invest in a robot or for those with existing automation, robotic simulation can provide information and insights that can make shop floor automation more effective and user-friendly.

Here are five ways fabricators can take advantage of robotic simulation software.

1. Ensure the Robot Is Right for the Job

When looking to invest in a new robot, in most cases the smaller the robot, the better. For the most part, small robots have higher acceleration and deceleration rates and can move faster between any given points than their larger counterparts. The downside with a small robot is that it tends to have a lower maximum payload.

Lots of variables go into choosing the right robot for a given task.

“For cell developers, simulation helps in designing the cell, selecting the right robot (and positioners and/or linear slides) for the application, and ensuring that the [welding] robot can reach all the joints without any collisions,” said Yarek Niedbala, vice-president of sales, KUKA Robotics Canada Ltd., Mississauga, Ont.

One of the big advantages of the software is that it can be used before any capital investment is made. Purchasing a robot that is not up to task or that doesn’t fit in the space allotted can be an expensive mistake and can set shops back significantly.

“Fabricators don’t need to have the robot on hand, the tooling manufactured, or the dedicated floor space to see exactly how it will all function,” said Stephen Kelly, product specialist, ABB Robotics, Brampton, Ont. “The software can validate the application in advance, provided you have some basic information about the robot cell. With limited information it can determine if one or more robots are needed, in how many seconds it can perform the task, and if the payload is appropriate.”

Most robotic simulation software allows a fabricator to access the industrial robotic manufacturer’s catalogue of offerings. The user can look through a list of options, find the right payload, and see all the robots that are available in that range.

“Arguably the most important way to use simulation software is before you buy a robot,” said Dale Arndt, director, engineering and integration, FANUC Robotics, Mississauga, Ont. “You need to make sure that the robot you invest in is able to reach everything you want to reach and move everything that needs to be moved.”

Simulation software, if it’s used properly, can sort through various risks quickly and make sure that you’re reducing it as much as possible. It’s not only reduces risk, but can optimize the operation of machinery. FANUC Canada

The software also can determine if an existing robot is suitable for a new application and alert you to maintenance needs. If a robot requires replacing, it can tell you if a bigger or smaller option is available.

“All you would have to do is create a virtual backup of the robot,” said Arndt. “You can swap it out for a new robot of a different type and you can evaluate the impacts of making such a change. Or if the robot gets damaged or something creates a stoppage, you can load the backup into the simulation and figure out how to get it up and running again.”

Having accurate manufacturing specifications and information can make all the difference in ensuring that the robot selected works in a shop’s physical environment.

“Fabricators can import CAD models of the environment and additional information needed,” said Kelly. “From there they can drop in a robot, power it up, and do a simple study. It’s very much like virtual shopping and allows for trial and error in a virtual environment.”

2. Ensure the Cell Functions Effectively

One of the more traditional ways to use robotic simulation software is to create a workcell and see how the robot functions within the environment. The robot can move around within the cell, the software records the location, and the user can program the robot and run the program.

“Everything that can be done on the physical robot can and should be done in the simulation first,” said Arndt. “And what you see in the simulation should be exactly how it runs in the real world. Simulation is quite often used to teach new operators and users how to program properly before they touch a real robot, which, if done incorrectly, can have serious repercussions.”

For this to work effectively, shops must have accurate information about the shop floor, manufacturing processes, and other metrics that might affect the outcome of the simulation.

Ideally a shop should have CAD models for all parts, tooling, fence line, and existing cell components. That way when the operator runs the simulation or visualization, he can see the robot moving in a space that mimics the real world with all the necessary parts and equipment there.

The software can evaluate cycle time, add more robots that can then be tested in the confined space, and determine motion limits. If the robot is responsible for handling and stacking boxes, the software will determine how high they can be stacked before the robot cannot reach.

“You don’t want to perform a simulation in a perfect world and then get to the plant floor and realize there is a column in the middle of the cell or some steel in the way,” said Arndt.

The software allows the virtual program to provide a frame of reference in the virtual environment that can be replicated in the real world. The robot is then taught where those frames are and the program lines it up so there is no time cycle lag or point offset.

“Generating a robot program for a new part in simulation means that production on the actual cell doesn’t have to be interrupted,” said Niedbala. “This can represent many hours of saved production time per part. After the new program is loaded in the controller it can require some testing since there could be slight differences between the virtual program and the actual cell. Some of these differences can be addressed by adaptive technologies developed specifically for this purpose.”

3. Avoid Accidents and Collisions

As long as the software is provided with good information in the simulation environment, it should react accordingly in the real world.

“With accurate information inputted into the software, there’s no guessing whether you have to have a safety buffer, whether adding a second robot will be needed, and how it will interact with the first,” said Kelly.

Running a simulation test in an empty environment is possible but not helpful when it comes to safety and productivity.

“With the proper CAD models, the user can go into the simulation and do the whole program, making sure there are no collisions or interferences,” said Kelly. “It’s certainly a good safety tool and we can program safe mode, which restricts the robot’s motion and can determine stopping distances.”

Setting up a cell oftentimes involves a lot of people performing a lot of different functions. The simulation software allows all aspects of the process to come together in one place to determine if it all works together and capture any possible errors up front.

“Robot crashes in the simulation environment have no consequences,” said Niedbala. “In the real world, a crash could mean expensive and time-consuming repairs to the [end effector] or robot arm.”

4. Maximize Productivity

Robotic simulation software can be used, first and foremost, as an offline programming tool.

For example, if a shop needs the robot to dispense adhesive around the peripheral of a door panel, the simulation software can use tools that would trace out and create an automatic path for the robot to follow within seconds. Without the software an operator would have to jog the robot, teach a position, jog it again, and teach it again to create hundreds of positions to complete the task. That could take several hours.

“I could do that in the software within two or three seconds,” said Kelly. “It’s a significant advancement to working with a pendant on the shop floor.”

It also can be used to program new parts offline. For example, if a shop is welding a part and a new model is available, rather than shutting down the cell to program the new part, the software can load new CAD models into the virtual cell and program them offline.

Kelly explained that he worked with a shop to develop an offline program that took approximately three days to complete, saving a day and a half.

“Initially I was disappointed, but the operator explained that this was great,” said Kelly. “Three days on a computer versus four-and-a-half days on the real robot, where it would be shut down at a cost of $60,000 per day. That’s a huge savings when you look at it that way.”

Programs taught in simulation can be optimized quicker because more test scenarios can be evaluated without fear of damaging the equipment, according to Niedbala. It also can determine how much time and money a shop can save by moving from a manual to automated process.

“Simulations can help estimate the total cycle time that the welding process will take, and thus help calculate how much money the shop will save by switching from manual to robotic welding,” said Niedbala. “Of course there are other benefits to consider in ROI calculations, such as improved weld quality, consistency, and reduced scrapped parts. Since the robot performs the job consistently and without breaks, the cycle time analysis helps the shop quote new parts more accurately.”

He added that simulation offers the programmers the ability to program new parts anywhere, anytime. Operators are no longer required to be in front of the robot for hours holding the teach pendant.

“It also eliminates the need to experiment in production,” said Arndt. “You can load a robot into simulation and make any change you want, move fixtures, add conveyors, and see how it will work offline without impacting the day-to-day operations. You can also do very sophisticated optimization related to reducing power consumption of the robot, reducing slow downs and production stops of the robot, or recording all the vision images and looking at them to see what is causing downtime. Some software can analyze production information over time and identify if a robot, process, or cycle time is changing. And then it will alert to ways to improve or correct it.”

5. Demonstrate How the Cell Will Look and Function

The No. 1 misconception about robot simulation software is people think it just makes pretty videos to sell their management on.

“That may have been true a long time ago, but now a simulation software is used to reduce risk for everybody,” said Arndt. “If it’s used properly, it can sort through various risks quickly and make sure that you’re reducing it as much as possible. It’s not only to reduce risk, it can optimize the operation of machinery. It can provide all stakeholders with a vision and example of just how the cell will look and work. It is a very valuable tool for so many reasons.”

The virtual environment allows manipulation, changes, adjustments, movements, and whatever else a shop wants to try and explore before actually doing it. Does it make a difference? Does it make production better? What will it look like on the shop floor?

Some simulation software can support 3D visualization or immersive technology. For example, operators can use Oculus Rift, HTC VIVE headsets, and other 3D technology to immerse themselves in the virtual world and step into the simulation.

“It’s an excellent visualization tool. It’s not fully mature in terms of doing high-level programming, but it certainly can be used as a secondary check to see if what you think you’re doing is the right thing,” said Kelly. “One example where this might work is in a body-in-white line, where spot welding or adhesive is being added inside that structure. Programming virtually on a computer with a 2D screen can be somewhat cumbersome. A 3D visualization through the headset allows the programmer to stand inside the car and allow for the robot to be pulled from the outside into the car, and the user can then see exactly what operations are being performed and how. It’s just one new way that the software can be used.”

Reposted from Canadian Metalworking https://www.canadianmetalworking.com/canadianfabricatingandwelding/article/automationsoftware/5-ways-to-take-advantage-of-robotic-simulation