Continuous material flow instead of manual transports: Adient automates plant in Torslanda, Sweden, with mobile robots

Together with Safelog, a mobile robot system was developed that fully automates material transport between the warehouse and the line, ensuring a stable and continuous material flow today.

Manual logistics as a limiting factor

Before the project started, material carts and trolleys were moved using forklifts and industrial trucks. This approach was not only labor and cost-intensive but also highly prone to fluctuations. During peak loads, there were regular waiting times, interruptions, and a lack of synchronization between the warehouse and the line. Under these conditions, a continuous material flow could not be reliably ensured, which proved to be an increasingly critical factor given the increasing variety of variants and cycle requirements.

Mobile Robot Fleet as the Backbone of Line Supply

The solution currently in use is based on mobile robots that fully take over the transportation of trolleys. Transport orders are triggered via a user interface, vehicles pick up empty carts from the line, transfer them to designated handover positions in the warehouse, and bring full trolleys back to the production areas. The system is designed for a cycle time that allows transport every 50 seconds, ensuring a consistent, demand-driven supply to the production lines. If no order is available, the robots automatically use charging stations and secure their availability through "Opportunity Charging."

A special feature is the communication between the mobile robots and cobots, which are used in the assembly of seat backs. If a cobot reports its material needs to the transport robot fleet, a mobile robot brings a full material cart from the warehouse to the production line. There, it positions the cart at the cobot's workstation, and the seat backs are transferred to a material depot using Karakuri technology through gravity, from which the cobot draws. The empty cart is immediately returned to the warehouse.   

Layout Optimization Instead of Mere Automation

A key success factor of the project was not solely in automation, but in the consistent redesign of layout and traffic management. Handover and parking positions were relocated, travel directions adjusted, and stations rotated to reduce shunting times. Additional bypass routes alleviate crossing points and prevent deadlocks. Potentially critical traffic areas were analyzed early and directly incorporated into the system design, which was secured through static calculations and simulations.