Some jobs in auto plants are better off automated. And that's especially true when it comes to day after day repetitive lifting of heavy engine parts that can cause back and shoulder injuries.

That's where a fleet of 12 automatic guided vehicles (AGVs) came into the picture at a DaimlerChrysler engine factory. They replaced lift trucks that previously transported parts and required workers to manually handle heavy engine parts.

The laser-guided vehicles transport engine parts to workers at 82 workstations. Each vehicle is outfitted with a single-load conveyor top and has a 4,000-pound capacity.

Workers order parts as needed using a centralized material delivery system. The AGVs pick up the parts and bring them to chain-driven roller tables that convey the parts to assembly work cells. Transfer of the heavy parts is completed without any manual involvement by workers, significantly improving the ergonomics of the operation. The vehicles' quad-steer dual drive ensures that the AGV is precisely lined up to make

the transfer. In addition, the AGVs move the work-in-process parts promptly between assembly stations, eliminating clutter.

Beyond improving ergonomics and materials handling efficiency, the AGVs have also added to the plant's overall productivity.