Fully automated production supply thanks to AMR fleet and special robot

DEHN SE is taking another step towards the future - in order to counteract the shortage of skilled workers and achieve its growth targets, the Bavarian company decided to expand its production facilities. A modern, 30 percent larger production facility with a fully automated production supply system was built in neighboring Mühlhausen. At the heart of the production logistics implemented by Unitechnik Systems are a driverless transport system and a specially developed gantry robot with a multifunctional gripper unit.

Founded in 1910, DEHN SE is now one of the world's leading electrical engineering companies. With over 1,100 patents, the family-owned company from Neumarkt i. d. Oberpfalz is an innovation leader in the fields of lightning, surge and industrial safety. DEHN products protect people and buildings, plant and telecommunications technology, the process industry as well as photovoltaic and wind power plants. The portfolio comprises over 4,000 devices and components. The company employs more than 2,400 people worldwide.

Relocation and modernization of production
Mühlhausen, around 10 km away from Neumarkt, has been home to the logistics center for production supply and shipping since 2014, as well as a small part of the family company's production. A new two-storey production hall in Mühlhausen, built at a cost of around €50 million, now houses the majority of production, consisting of existing machines as well as new acquisitions. Overall, production has increased by 30 percent over an area of 20,000 m2.
Another argument in favor of the production expansion in Mühlhausen was that previously all the components required for production had to be transported by truck from Mühlhausen to Neumarkt and the finished products back again. This effort can be significantly reduced by the move. In order to be able to meet the increasing demand efficiently in the long term, those responsible opted for ultra-modern production logistics. The goal: a high degree of automation and unmanned material transport both in the warehouse and in the production area. DEHN was looking for an expert who could implement a scalable system that is both flexible and decouples the production and warehouse areas from each other.

Unitechnik supports the planning of production logistics
In order to determine the requirements for the automated production warehouse and the capacities, DEHN commissioned an external planner with the rough planning. After determining the material flow figures, the storage space requirements and the rough concept, those responsible decided on a fully automated production supply system using an automated guided vehicle system. DEHN commissioned Unitechnik Systems GmbH with the detailed development of the optimum logistics concept. The planning included the comparison of alternative storage systems, the material flow layout, the design of the picking workstations and the definition of processes and interfaces as well as the robot concept for stacking the containers on the floor rollers. Floor rollers are used at DEHN as load carriers to supply the production lines.

Among other things, particular attention was paid to the ergonomics of the workstations. For the planned picking stations, DEHN built and tested the workstation in cardboard on a scale of 1:1 based on the 3D data from Unitechnik. This approach is also known as cardboard engineering. This allowed the employees to try out their future workstation and provide valuable feedback in advance.

After the planning phase, the contract for the implementation of the logistics system was awarded. "We have already worked successfully with Unitechnik on the implementation of our logistics center in Mühlhausen," says Christian Müller, Director Logistics at DEHN, explaining the choice. "We therefore have great confidence that the implementation of the production logistics is also in good hands with our long-standing partner."

43,000 storage locations for the production material
In addition to the expansion of the existing UniWare warehouse management system, Unitechnik's scope of delivery included a new shuttle warehouse, the container conveyor technology, four picking workstations, a multifunctional gantry robot, the connection of the AMR system and the entire control and safety technology.

The new shuttle warehouse has two aisles with 42 rack levels. The approx. 43,000 storage locations are served by 14 shuttles per aisle. Each aisle also has two container lifters and one shuttle lifter. In addition to storage containers with unfinished and semi-finished parts, pre-picked goods are also stored there. The container conveyor technology connects the warehouse with four picking stations, the robot transfer stations and various storage and retrieval points. The special feature: six different container sizes have to be transported and stored, each with and without a lid.

At the picking station, the employee responsible takes the required quantity of components from the source container provided and fills an order container of the appropriate size with them. A precise scale helps him with the "counting".

Special gantry robot as the linchpin of production logistics
The heart of the automated system is located between the warehouse and the production zone in an area separated by protective fencing - a specially developed gantry robot with a multifunctional gripper unit. This is responsible for distributing and stacking the pre-picked containers on the floor rollers. The challenge: the different load carriers require a multifunctional special robot. Unitechnik implemented this requirement in cooperation with the gantry robot specialist RO-BER. The in-house development can grip up to six different container types as well as Euro pallets and floor rollers. The robot automatically stacks the different containers of an order on a floor roller according to a layout calculated by UniWare. A driverless transport system then picks up the fully loaded floor roller and moves it to a buffer area, the so-called supermarket.

The robot is also responsible for automatically receiving goods from other plants. A driverless transport system moves the pallets with stacked containers directly into the robot cell. The robot recognizes the type and position of the individual containers, picks them up and places them on the conveyor system. They are then stored in the shuttle warehouse.

AMR fleet serves the workstations
When it comes to driverless transport systems, a distinction is made between classic track-bound AGVs and autonomous mobile robots (AMR), which can navigate freely on the surface. DEHN has opted for AMR from Agilox. These are equipped with swarm intelligence. This means that the system dynamically decides which vehicle takes on which task based on the current situation. A total of nine ODM AMRs were modified in close cooperation with DEHN. The main task of this AMR fleet is to transport the floor rollers with the material for the production orders. First, the goods are picked up in the robot cell and placed in the supermarket. This decouples production from the storage area. When an order is called up, the next free AMR transports the corresponding floor roller from the supermarket to the production line.

The AMR fleet is supplemented by four ONE devices, which carry out pallet transports and transport goods between the production area and the adjacent logistics center.

UniWare controls distribution and production logistics
The brain of the logistics systems at the entire Mühlhausen site is the UniWare warehouse management system with integrated material flow control and system visualization. A particular challenge in this project was the stack formation on the floor rollers. The optimum structure of the container stacks had to be calculated from a large number of parameters and dependencies.

As the hub of the logistics center, UniWare has interfaces to the SAP ERP system, the Hydra MES system, the RO-BER portal robot, the Agilox AMR system and, of course, the Unitechnik PLCs for warehousing and conveyor technology.

Combating the shortage of skilled workers with automated transportation
Despite the pandemic and the war in Ukraine, the new production warehouse in Mühlhausen i. d. Oberpfalz was completed on schedule in June 2023. Robert Berger, Project Manager at Unitechnik, draws a positive conclusion: "The cooperation with DEHN was very constructive at all levels and focused on the common goal," says Berger. "Despite the external influences, we were able to complete the project to the satisfaction of everyone involved."

The project was also a complete success for Christian Müller: "In addition to the integration of the AMR fleet, the planning and development of the gantry robot was a challenge that our partners from Wiehl mastered with flying colors," he sums up. "Thanks to the automated production supply, we are ideally positioned for future growth on the one hand, and on the other hand we are avoiding the shortage of skilled workers in our region."


At the heart of the automated system is a gantry robot with a multifunctional gripper unit

Shuttle warehouse with 43,000 storage spaces in two aisles with 42 shelving levels

The bin conveyor system connects the warehouse with the picking area and the robot handover stations

Picking materials for production orders

The gantry robot can grip up to six different bin types as well as Euro pallets and floor rollers

Bins of different sizes are stacked on a floor roller

A buffer area, also known as a supermarket, decouples production from the storage area

AMRs transport the floor rollers from the supermarket to the production line