Automation solution for a handling and transfer unit
Intelligent handling of standpipes
The custom machine manufacturer RTT required a customized automated standpipe handling solution for an end customer in the roof drainage sector. SEW‑EURODRIVE provided the complete drive and automation solution for the system consisting of four SCARA robots, including the kinematic models for component removal.
Success through close collaboration in development
RTT, the custom machine manufacturer from Zittau, was tasked with creating a customized automated handling solution for an end customer, a well-known manufacturer of roof drainage systems and drainpipes. The objective was to remove standpipes with lengths from 25 centimeters to 4 meters and weights of up to 30 kilograms from the laser cutting machine after the cutting process, transport them, and finally to place them on pallets for packing. The handling and transfer unit needed to weigh as little as possible and fit in the limited space available on site.
SEW‑EURODRIVE provided the entire drive and automation solution for this system, which consists of four SCARA robots and is guided along the ceiling. It was clear from the beginning that the application specialists from SEW‑EURODRIVE would closely and actively involve RTT in the planning and development of the tailor-made system and the associated robot kinematic model based on the MOVI-C® modular automation system and would share their expert knowledge.
For us, there was no question of turning to anyone but SEW‑EURODRIVE for their expertise and products in this project, too. We know how high the product quality is, and have already worked with them successfully to create several other specialist machines.
We were particularly impressed by the precision and stiffness of the ZN.. servo drives.
Mr. Richter assured us from the start that we would be able to find a solution for this complex task together, and we have achieved that.
Quote Andreas Richter, head of SEW‑EURODRIVE's Dresden Technical Office
It's not possible to use a conventional robotics solution for this specific system. The task requires a special design with specific kinematic models. We know how to do the calculations, and have suitable automation modules. It is impressive to see the speed and elegant dynamics of the robot arms as they handle and move the standpipes at the end customer's facility.
SCARA robot arms handle standpipes in a small space
Everyone knows them: Standpipes are used, for example, to conduct water from rainwater downspouts from roofs into the sewer system. They are also installed in hydrants as part of the water-conducting equipment.
Handling these metal pipes was the objective of the system project carried out by the custom machine company RTT for one of its customers. The standpipes can weigh up to 30 kilograms and be up to four meters long and after they have been cut to length, they have to be removed from the production line and transported over a distance of 12 meters to then be bundled and packed on pallets. The solution: a handling and transfer unit with four SCARA robots which hangs from the ceiling and is guided along a linear axis.
SCARA stands for "selective compliance assembly robot arm". This is an articulated robotic arm made to imitate a human arm. In the handling and transfer unit from RTT, the gripping range of the complete SCARA arm (extended "upper arm and forearm") measures 2,200 millimeters.
The four SCARA robots can be operated independently of each other. Depending on its length, one pipe may also require two arms. In this case, the two arms operate together on one side of the linear axis. In a perfectly synchronized duet, this pair can handle heavy standpipes up to four meters long. Each of the four lightweight SCARA gripping arms also has a vacuum gripper with correspondingly strong suction plates.
Zero-backlash servo drives for challenging kinematic models
Each of the SCARA robot arms is equipped with three servo drives. One of these, a BS.F..CMPZ.. helical-bevel servo gearmotor, serves as the X-axis drive and moves the robotic gripping arm along the linear axis. The CMPZ.. motor offers additional rotor inertia especially for such applications with high load moments of inertia.
The other two drives are precision servo gearmotors equipped with two-stage cycloid planetary gearmotors from the ZN.. series. They move the gripping arm itself – one moves the "forearm" and the other moves the "upper arm" of the gripper.
These precision servo gearmotors are characterized by their high resistance to torsion and tilting and their exceptional mechanical backlash properties and overload capacity. This allows for reliable solutions to demanding applications in which exact positioning and fast, repeatable movements are required even with large loads. Thanks to their remarkably compact design, these ZN.. gearmotors fit in even the smallest of spaces.
Central control of the four robot arms
The use of our MOVI-C® modular automation system means that all the components – from the engineering software for the control and inverter technology to the motors – work together perfectly. The benefit for RTT and its end customer: The entire automation solution for the robotics system comes from a single source.
The MOVIDRIVE® modular application inverter used for the handling and transfer unit is a flexibly configurable multi-axis system. Another key component of the system is the custom implementation of the complex kinematic models using our MOVIKIT® Robotics software module.
The kinematic models for component removal were completely simulated as early as the project planning phase. Based on the results of this simulation, our application engineers were able to design and optimize the drives specifically for this application. This also allowed the system to be put into operation for the end customer particularly quickly.
Thanks to the preconfigured MOVIKIT® Robotics software module, the kinematic models for the SCARA gripping arms could be parameterized quickly and easily. Only a few commands in the SEW robot language were necessary to precisely define the motion sequences.
Another benefit of our automation solution: The "robot monitor" user interface provided the perfect overview for operation during startup. Even complex functions can be easily mastered with this clear and intuitive user interface. It shows a three-dimensional representation of the kinematic models of the robots and provides accurate insight into the traveled paths.
The project managers from both RTT and the end customer were highly satisfied with the time savings achieved with this method. And especially because it provides the opportunity to adapt the system quickly and easily to future changes.