SEW drive their own project management
SEW Eurodrive’s highbay warehouse extension in Graben, Germany
SEW Eurodrive’s motors and drives enjoy an excellent reputation in the field of logistics, and their energy-efficient, high-performance systems are incorporated by MLOG Logistics into its range of automated storage and conveying equipment. This winning combination was demonstrated in SEW’s high-bay warehouse extension project in Graben, Germany in which MLOG employed the customer's latest drive technology during the integration of three new storage and retrieval machines.
During the course of the past 80 years SEW has evolved from Southern Germany’s electric motor plants in the Baden district of Bruschal to become one of the world’s market leaders in drive engineering. With over 13,000 employees and a turnover of almost 2 billion Euros, the company develops and manufactures international products for the industrial and leisure sectors, ranging from escalators and luggage conveyors to roller coasters and fun rides. Many system components are produced at the Graben-based plant which was recently extended by three storage aisles and an additional 7,560 pallet locations due to a lack of capacity. The customer took charge of the extension project management whilst MLOG supplied the new storage and retrieval machines.
MLOG’s services also included the supply and assembly of aisle equipment and the complete racking steelwork, including conveyor platforms and fencing. The project took six months to complete and any work which could have interfered with plant operations was carried out at weekends. The racking steelwork was assembled during the first six-week phase and the aisle equipment was installed three weeks later. Subsequently the storage and retrieval machines were assembled and integrated with the existing control system.
A major aspect of any upgrade and extension project is to maintain and optimise the system operation and related processes. MLOG therefore adapted the design and functionality of the new components to the customer’s standards to ensure that the operation of the new storage and retrieval machines was precisely matched with that of the existing machines.
Flexible load-handling capacity
Three “MSINGLE B” storage and retrieval machines reaching a height of over 22 metres were integrated into the system. Each one is fitted with two load-handling devices featuring automatic load detection, enabling pallets or steel crates with a working load of 1,000 kg to be transferred to and from stock. Maximum performance is 48 pallets per hour (double cycles) or 70 pallets per hour (single cycles).
SEW’s latest three-phase motors and Movidrive inverters were used to drive the running gear, lifting units and load-handling devices. Thanks to an integrated energy recovery system they are particularly efficient and promote high-performance and low power consumption whilst enabling maximum running speeds of 180 m/min and lifting speeds of up to 60 m/min.
Each storage and retrieval machine is fitted with a Siemens S7 PLC mounted in an end-of-aisle control cabinet which communicates via Profibus (and infra-red photoelectric devices) with the (ET200) devices mounted on the storage and retrieval machine. Wireless connectivity is also provided to enable on-site or remote maintenance. MLOG also updated the Profibus DP modules on the existing s/r machines to optimise communications with the conveyor system controls. This control technology is located in the s/r machine on-board control cabinets together with the inverters.
Positioning and monitoring
The s/r machines and their load-handling devices are positioned within an accuracy of +/- 1.5 mm by use of absolute encoders and laser distance sensors. The positioning modules integrated within the SEW Movidrive controls guarantee optimised positional routing. Two barcode scanners located on each lifting carriage monitor the containers to ensure that unit loads and unit load data is always matched.
MLOG also installed camera systems on the s/r machine lifting carriages to provide invaluable information in the event of malfunction. The camera images are stored continuously in a 40 second “ring-buffer” and encrypted images are transmitted via wireless network access points to enable the recording of the last 40 seconds of operation prior to any malfunction, thus enabling rapid trouble-shooting.
Even during the productive phase prior to final acceptance, the availability of the s/r machines was clearly above 95 percent.
The variable load-handling devices can simultaneously handle 2 pallets or containers.
The latest equipment features energy efficiency, low power consumption and high performance.
During the extension project, each aisle was equipped with one MSINGLE storage and retrieval machine with running gear and lifting units featuring the latest SEW MOVIDRIVE equipment.
