Rapid prototyping: Robots with feeling
Digitalisation and industry 4.0 | innovation | Smart factory | Simple repetition of processes is a thing of the past; the future demands flexibility. At the Advanced Robotics Lab, a young team is working on the robot revolution – much to the excitement of potential users.
Very precisely, iiwa clasps the cable conduit and moves his fingers up to the plug at its end. As soon as he has reached it, he shakes the small plastic component until he has firmly taken hold of it. Now, the plug has to be inserted into the socket of a control unit. He makes a slight turning movement toward the target, carefully inserts the plug, and then gives it a gentle shake – until the plug slowly enters the socket and is finally in place. Then iiwa again grasps the conduit and carefully presses it into a fastening clip on the steering gear. Everything is in place – job done. Anybody who observes iiwa at work could almost think he was human, as his actions and movements so closely resemble those that production workers would make in performing this operation. However, iiwa is not a human but a one-armed lightweight robot.
Precise robot hands
The experts at the Advanced Robotics Lab in Liechtenstein are using iiwa to work on new applications for these intelligent machines. The word “advanced” has a very specific meaning here. “Today, we use robots mainly for handling parts in production work. This is about the precise repetition of processes,” explains Andreas Münster, who is in charge of the laboratory. “In the future, though, we also want to use them for value-adding activities – for example, for inserting plugs or in joining processes.”
Flexibility is the key
However, this will require new capabilities. In the future, it will no longer be enough to constantly repeat the same process tirelessly and with micrometer precision. Instead, robots will have to learn to deal with uncertainties and to respond flexibly to feedback from the process. “For example, iiwa does not know the location of the plug that he needs to insert into the socket,” Münster says. “That is why he first looks for the cable conduit with his two steel fingers and then runs them along it until he reaches the plug,” Münster explains. Pressure sensors signal to the robot when it has caught hold of something and whether the force used to insert it into the socket was great enough. Cameras are not used here, and this means iiwa’s actions are slightly reminiscent of those of a human who has to perform a task blindfold and who feels their way by using the feedback from their fingers.
Out of the cage
For production work, the use of sensitive robots promises lower costs, better quality, and more flexibility. Cooperation between humans and machines, too, will change fundamentally, because sensors now enable modern robots to take account of their surroundings. If a human comes too close to them, for example, they simply stop moving. This means they can now be let out of their cages to work with humans in production. Alongside these sensitive robots, therefore, the team’s second focus is on collaboration between humans and robots. “Collaboration is the final stage in a development that starts with robots working in isolation and then goes on to coexistence and cooperation with humans,” Münster says. “A human can intervene in the process at any time, while the robot simply carries on working – this is our top priority.”
Together with his team, Münster is working on turning the robot revolution into reality at thyssenkrupp. Interest within the Group is high. He regularly meets potential users for workshops to evaluate scenarios for the use of robots. In this process, Münster’s coworker Sebastian Schädler, who is driving the implementation of concepts and programming at the Advanced Robotics Lab, discusses requirements with production planners and colleagues from the Group’s plants and works out ideas for solutions. “At the beginning, we leave out many details of the assembly process, so that we do not get bogged down in technical details during our concept studies,” Schädler explains.
One idea has already been put into practice. In Florange in France, “Albert” is now an integral part of the workforce and very skillfully assembles sealing rings in sensor housing. The idea for this dual-arm YuMi robot naturally came from the Advanced Robotics Lab. Three more projects are currently being implemented.
A team of pragmatists
Speed and flexibility are the hallmarks of the Advanced Robotics Lab in Liechtenstein. The young team have two robots available to them for their experiments. In addition, developers at the neighboring thyssenkrupp training workshop can at short notice produce parts themselves or have them made by a 3D printer. If, despite this, there is still something missing, they can obtain standard items like aluminum profiles on the spur of the moment and adapt them with simple tools, or sometimes they use materials from model construction to enable them to make a gripper or clamping device as quickly as possible. The control software for the robots is likewise created through teamwork within a few days; the team have just noted on a board how iiwa’s seven axes need to move for the latest project.
From robot sketch to concept within 7 days
This work calls not for sophisticated engineering but for fast, pragmatic solutions – for example, when special modeling clay and screws have to be used on a robot’s gripper to enable it to handle sealing rings. “With rapid prototyping, we can present our partners with a first version within a week after the brainstorming session,” Münster says. “This is perfectly adequate for assessing its prospects of success. This approach also prevents great ideas being rejected too quickly.” After this, it takes a few months before a robot is actually in use in production – where it can then prove that humans and machines can work together very well as a team.