A Dynamic and Important Sector for Cables

Holger Dietz: Six-axis robots are extreme environments for cables: they must withstand bending, torsion, tensile loads as well as other conditions. Robots also operate in extreme temperatures and come into contact with dust, dirt, moisture and chemicals. This really is a particularly challenging environment.

Janik Ebner: Cables and connectors are critical components in robotics where there is a risk of failure after millions of movement cycles. It goes without saying that our robots are designed so that the cables never kink. But it’s torsion in particular that can’t be avoided in many applications.

Benedek: It is this aspect, above all, that makes robotics such a fascinating area for us as a cable manufacturer. In order to enable movement along their longitudinal axis, our robotic cables are constructed very differently to other cables. This begins with stranding and goes beyond the conductor insulation and twisting to special foils and fleeces which are fitted into the cable to make them torsion resistant.

Vincenzo Rio: When it comes to robots used for welding, the issue of welding spark resistance also needs to be taken into account. We’ve been getting more and more inquiries lately about this, including ones from the automotive industry.

Horst Messerer: Of course, we spend a lot of time thinking about the service life of our cables - but the cable is only one part of the robot. There are also electronic components that can break, or bearings and motors that can wear. Even data cables grow old over time and become more susceptible to faults. In applications with real time data transmission, packet or bit errors will eventually affect the performance of the overall system. For example, it could affect the timing of a machine. But where the boundaries lie very much depends on each individual case. This is why condition monitoring of data cables is also a concern of ours.

Ebner: For predictive maintenance, diverse data, such as the distance travelled by the motors, is collected and transmitted from the robot. Based on empirical data, for example, it’s possible to very accurately predict when an axis needs to be serviced or a tool needs to be replaced.

Dietz: Robots in the automotive sector – for example on welding lines – have a service life of up to 16 years. The right cables can cope with that without any problems. In addition, the topic of retrofitting robots is currently on the rise. Because the delivery times are sometimes very long for new models, there’s a lot to be said for retrofitting and repairing old robots. It might also be a good idea to replace the cables at the same time.

Wurll: When a robot stops working properly, it’s most likely due to a broken peripheral component such as a gripper or the welding technology. Their repair is the responsibility of the system integrator who fitted the robot with the components. Peripherals account for the bulk of the costs of most robotic systems. Therefore, this is where the focus should be when it comes to planning predictive maintenance.

Kraus: One of the most important points is to avoid accidents as much as possible. After all, the risk of being injured by a cobot without a safety fence around it is significantly higher than by an industrial robot in a completely enclosed space. People working with robots need to be appropriately trained, for instance by passing a sort of “robot driving test”. The fact that robots are also capable of executing unexpected movements at any time is often overlooked - This can quickly cause collisions. It’s for this reason that the travel speed of cobots is significantly slower.

Dietz: There have been attempts to monitor the behaviour of cobots using cameras in order to evaluate collisions and prevent them in future. Depending on the application, data protection rights need to be observed here as workers might feel that they’re under surveillance by such systems.

Ebner: It’s also worth mentioning that even though it’s possible to work collaboratively without spatial separation between the human and robot, there are plenty of operators who don’t want to do this. As a consequence, in practice, cobots are often not used as cobots, i.e., as collaborative robots, in the true sense of the word, but as compact variants of the more traditional industrial robot.

Benedek: I see a trend developing towards service robots. Robots will be deployed more and more in households, nursing homes and hospitals. For example, they’ll help people to lift heavy objects or do other things that they can’t do any more for health reasons. Robots already exist that autonomously go into hospital rooms, for instance, and disinfect them using UV light. I’m guessing there’ll be one or the other sensible or nonsensical idea for robots aimed at helping private individuals rather than industry.

Dietz: I see a lot of potential in the medical sector as well. Assisting robots are already being developed to perform endoscopic operations, for example. Such operations usually involve up to four doctors standing close to each other around the patient. By contrast, the robot has up to four arms and is controlled via a console, monitor and camera – this allows for a much better overview. Physiotherapeutic treatments or adjustable operating theatre tables are other major up-and-coming areas of application. Moreover, the use of robots is obviously preferable when it comes to working in areas that pose a danger to health or life, such as bomb detonation or nuclear reactors.