PSI Technics

PSI Technics Replaces Discontinued Trimble ICS5000L System

Volkswagen AG decided to retrofit their vehicle body warehouse in Wolfsburg, Germany, and chose PSI Technics’ Positioning Solution System as a replacement for their existing ICS5000 positioning systems. The Positioning Solution System is an efficient, reliable system that easily integrates into the existing warehouse infrastructure.

Warehouse logistics present a challenge for many German companies. Outdated positioning systems are still being used in many high-bay warehouses—a situation that is not limited to the automotive industry. At worst, malfunctions or failures lead to warehouse downtimes that can last for several days—a dreadful scenario in terms of “just-in- time” production processes.

Volkswagen AG was faced with this challenge. All stacker cranes in one of their high-bay warehouses in Wolfsburg were still controlled by Trimble’s ICS5000 system. The support for this system was discontinued at the end of 2009 and Volkswagen had been looking for a state-of-the-art system that could provide at least an equivalent if not better performance. High reliability, high throughput and long-term availability were vital criteria when it came to choosing a system. Volkswagen opted for the
Positioning Solution System manufactured by PSI Technics with headquarters near Koblenz, Germany.

Project Description

The Positioning Solution System is a stand-alone digital control system that automatically positions
stacker cranes in industrial facilities such as high-bay warehouses. The new positioning system was
installed at Volkswagen AG‘s high-bay storage facility in Wolfsburg. Approximately 990 vehicle bodies
for Volkswagen Golf, Golf Plus and Tiguan models are stored in an area of 131.2 x 229.6 ft (40 x 70
m). The warehouse serves as an interim storage prior to paint finishing. The system handles approximately 6000 runs per day on each axis and lifts the vehicle bodies to a height of 65.6 ft (20 m).
Since PSI Technics was involved in the modernization analysis and planning early on, the retrofitting
was completed very quickly. The process took on average one day per stacker crane. This way, costly downtimes could be kept to a minimum.

Jürgen Bastek, Manager of Maintenance, Volkswagen AG
„The retrofitting was well-organized and well-prepared. As a result, the new positioning systems were
commissioned even prior to the completion date.
PSI Technics’ positioning solution was most convincing as a replacement for the ICS5000L system.
The Positioning Solution System is technically sophisticated and can therefore readily be used in
production environments.“

So far, PSI Technics retrofitted the traveling and retractable axles of four stacker cranes and is going to modernize a total of ten warehouse stacker cranes.

The New Positioning System
The fast and easy integration into Volkswagen AG‘s existing logistics facilities was a major advantage of the new positioning system. The system permits the continued use of existing components such as PLCs, converters or motor drives. It interfaces with all major process control computers, controllers
and inventory management systems. At Volkswagen, the Positioning Solution System is controlled
by a PLC using the MODBUS TCP protocol. The system provides analog converter control within a range of -10V to +10V. A brake and a safety contact for each axis provide additional system control.

Advantages of Retrofitting: Easy Integration and Increased Efficiency

Another unique feature that supports a fast commissioning is the system‘s largely automated confi-guration. The Positioning Solution System automatically performs a characterization, eliminating
the need for a time-consuming manual control parameter configuration and adjustment. The characterization provides an optimized motion path based on the existing conditions. The system calculates motion profiles, placing particular emphasis on maximum speed and acceleration. During system operation, the Positioning Solution System uses feedback from optical distance meters to continuously monitor the stacker crane‘s movements. It optimizes the motion path in real time and completes storage and retrieval tasks within the shortest possible time. Acceleration and velocity profiles are based solely on linear ramps, irrespective of load, which completely eliminates creeping speed.

The shorter storage and retrieval times ensure the high throughput required by Volkswagen. PSI
Technics‘ web-based software interface provides access to all of the system‘s characterization, control
and diagnostic functionalities. The user-friendly software only requires a brief introduction—no
programming skills are needed. Failure detection is another innovative feature of the software. It recognizes minute travel changes or irregularities and triggers early warnings. If problems occur, the software detects them, so they can be addressed proactively at an early stage—an important feature that helps to prevent costly downtimes. The system is also equipped with a 1GB diagnostic memory. Service support is based on system error analyses, which can be performed remotely by PSI Technics‘ service technicians, if required.

Reduced downtimes lead to increased productivity

The new positioning solution completely fulfilled Volkswagen AG‘s expectations. The occasional downtimes that occurred with the previous positioning system are no longer an issue. According to Jürgen Bastek, the precision and the performance of the new positioning system were other convincing factors. The Positioning Solution System guarantees a reliable warehouse operation with retrofitted stacker cranes for years to come.