They are extremely hard-working, fast and reliable, and they move through production and manufacturing as if by magic. Not only is everyone talking about driverless transport systems, but such solutions are becoming ever more customary in major production plants everywhere. The technology has become far more user-friendly, and programming a service robot is relatively easy for the user.
Ease of use combined with the need for automation in general is what makes driverless transport systems increasingly popular. Electric linear actuators from LINAK® are used for multiple functions in mobile robots, typically for raising and lowering items. With the proANT transport robots, the Berlin-based company InSystems Automation GmbH offers an entire platform that can be specifically customised to meet the customer's requirements. The proANT transport systems are designed for loads of between 30 and 1,200 kilograms.
Kristof Parz, leading designer at InSystems, is constantly facing the challenge of developing customised vehicles able to meet customer requirements. The new proANT 654, built to transport floor rollers with containers, needed a design that included height adjustment. The robot has a fork arm that is positioned under the floor roller, which it lifts until the rollers no longer touch the floor.
"We used a LINAK actuator for the lifting mechanism," Parz explains. He never considered using a hydraulic solution because in vehicles of this size, it is extremely difficult to accommodate a hydraulic pump and the other necessary parts of a hydraulic system. Even a compact system offers limited advantages over the electric solution. On the contrary: control, positioning and the environmental balance clearly support an electric system. The necessary lifting force of 3,000 N and the maximum lift range of 65 mm are well within the performance span of modern electric actuators.
Safety is of major importance
Safety can be a complicated issue to implement. Driverless transport systems operate in the same environment as people, hence why very specific regulations must be followed. The lift limitation, for example, is highly relevant in this context. If the uptake goes too high, there is a risk that the system will be damaged and people could even be hurt or injured.
LINAK actuators provide various signals and position feedback. For the LA33, used in the proANT 654, analogue and digital position feedback is available for precise positioning. The internal end position is used as the lower reference point. Once the actuator reaches that point, it emits an end-stop signal. For the top-end position, InSystems uses an external sensor:
"For safety reasons, the top-end position is monitored by an additional sensor that is placed outside the actuator. Our transport systems move in places where people also work. That's why we need two independent redundant safety systems," says Kristof Parz.
In another project, the young designer had to use two electric actuators, running in parallel in order to lift a roller conveyor. This was where the IC (Integrated Controller) variants from LINAK proved their worth. The control electronics for this parallel operation were already integrated into the actuators, while a compact PCB for rail mounting organised the communication between the two actuators.
In addition to safety, reliability also plays a major role. To take full advantage of the cost benefits of automating workflows, the technology needs to work flawlessly in the long term.
"During daily use, our transport systems go over bumps and are therefore constantly exposed to shocks and vibrations. This means the integrated components need to be of really good quality. In all the components we use for our systems, including the electric actuators, we set high standards for quality," says Kristof Parz.
