Where production keeps moving: SEW-EURODRIVE
SEW-EURODRIVE is a global specialist in drive technology and automation, serving applications from baggage handling and parcel sorting to networked production. At its new smart factory for shafts and gear parts in Graben-Neudorf, near Bruchsal, the company has created a fully automated production buffer warehouse. The North Hall logistics module was delivered by SIVAplan and relies throughout on Leuze sensor technology.
Figure 1: For its fully automated production buffer warehouse (logistics module) in the North Hall in Graben-Neudorf, SEW-EURODRIVE relied on the experience and expertise of the sensor specialists from Leuze and the intralogistics experts from SIVAplan.
Systematic buffer
The single-aisle high-bay warehouse buffers production between gear and shaft manufacturing and the hardening shop. It decouples soft machining, hardening and hard machining, keeping processes flexible and reliably supplied. Built from 70 tons of steel, the warehouse has two nine-metre-high racks, each five metres wide and more than 76 metres long. Double-deep storage provides 2,300 locations. Two automated stacker cranes travel on one traversing axis, moving hardening racks between production, the furnaces and storage. Each loaded rack can weigh up to 510 kilograms.
Figure 2: The production buffer storage (logistics module) offers a total of 2,300 storage locations. Two fully automated stacker cranes work hard between the two racks. They load products from production onto the hardening racks and transfer them to the furnace system.
A clear run for mobile robots
SIVAplan implemented the logistics module as general contractor, including the higher-level control system. Together with PROCAM Steuerungstechnik, the company connected machines, systems and vehicles and linked processes to SAP ERP. Mobile robots from SEW-EURODRIVE bring finished components to the warehouse under master-controller guidance. At every material transfer station, two Leuze RSL 400 safety laser scanners safeguard access with a vertical protective field. The field opens only after the mobile robot has registered and closes again once it passes through. The integrated PROFIsafe/PROFINET interface simplifies connection to the safety control system.
Figure 3: Mobile robots at four material transfer stations deliver the gears and shafts produced on the production line. These are temporarily stored in the logistics module and then hardened in special furnaces.
In-process contour check
After an AGV transfers a loaded rack, conveyors move it to a contour checking station. Leuze HT25C diffuse sensors detect racks and control the conveyor system, while CML 720i measuring light curtains record rack contours during transit and send results via PROFINET. Further sensors monitor rack presence and control the light curtains. The diffuse sensors also ignore high-vis vests, preventing false detections near the transfer area, while Leuze industrial IP cameras provide additional rack images.
Safe loading and unloading
Each transfer station also includes a manual workstation for unloading and inspection. MLC 530-SPG safety light curtains protect operators, while Smart Process Gating enables sensorless muting and a compact layout. The PLC signal and the goods interrupting the protective field trigger gating, removing the need for additional muting sensors. Because hardening racks face extreme furnace temperatures and can deform over time, they are automatically routed for remeasurement after a defined number of cycles.
Figure 4: RSL 400 safety laser scanners from Leuze reliably safeguard access at the material transfer stations. They generate a vertical protective field and open up an access area once the mobile robot has registered. The mobile robot then delivers the goods through this area. Access remains secure on either side of the vehicle.
Reliable routing via barcode
After measurement, a stacker crane collects the rack for storage. Precise positioning is essential because both cranes share one rail. Leuze FBPS 600i safety barcode positioning systems, used with SEW-EURODRIVE MOVI-C® inverters, continuously monitor position and speed. This also safeguards two pedestrian walkways by holding cranes in defined segments when people need to cross.
Only one FBPS 600i sensor is required for safe position detection, simplifying integration. Two units are installed on each crane: one for the lifting axis and one for travel. Reading multiple barcode tape codes per scan, the system delivers millimetre-precise data via dual SSI. With Performance Level e / SIL 3 and a 10-millisecond error response time, it enables short braking distances and high warehouse performance.
Figure 5: During the contour check, the outer contours of the racks, together with the goods, are detected by measuring CML light curtains from Leuze. Additional Leuze sensors are installed to monitor the presence of the racks and control the light curtains. Practical: Sensors that detect objects ahead in the direction of the delivery area are designed to ignore high-vis vests to prevent incorrect detections.
Camera-based precision compartment placement
Leuze sensors also support the stacker cranes and storage compartments. Diffuse sensors detect rack presence. Once a stacker crane reaches its storage location using barcode positioning, it performs compartment fine positioning so the loaded rack is placed precisely. A camera-based Leuze IPS 200i sensor with integrated PROFINET interface is mounted on each crane. The compact sensor works at distances from 100 to 600 millimeters and focuses on a reflector attached to the shelf support. If the marker is within range, it sends absolute values to the SEW controller, enabling precise rack transfer without multiple diffuse sensors.
Figure 6: At the workstations where goods are inspected manually, MLC 500 safety light curtains ensure that goods can be safely removed and reloaded at all times.
Figure 7: One of the stacker cranes in the maintenance area. The stacker cranes load the warehouse with racks weighing around 500 kilograms, reaching heights of up to nine meters.
Figure 8: The stacker cranes are controlled via FBPS 600i safety barcode positioning systems from Leuze. Two devices are installed on each stacker crane: One is used to position the lifting axis – it reads the codes printed on a bar code tape attached vertically to the stacker crane. The other determines the horizontal position along the travel axis
Figure 9: Leuze sensors also support compartment fine positioning: An IPS 200i camera-based sensor mounted on the stacker crane focuses on a reflector attached to the shelf, suitable for positioning tasks at distances ranging from 100 to 600 millimeters. Retro-reflective photoelectric sensors (top right) also detect the presence of racks on the stacker crane.
Figure 10: A seamless solution from start to finish Using innovative sensor technology from Leuze, SIVAplan has developed an innovative, automated production buffer storage (logistics module) that makes SEW-EURODRIVE a pioneer in the field of smart factories.
