John Deere: Automatic guided vehicles move tractor cabs through the production line

John Deere Waterloo, Iowa
Size: 5.9 million square feet; more than 2,734 acres
Facilities: Deere operates six manufacturing facilities on the Waterloo campus
Products handled by AGV: CommandView II cabs for 7R, 8R and 9R series tractors
Employees: 5,000
Shifts/Days: 2 shifts/5 days

The CommandView II cab production line is a good example of how a leading manufacturer has applied automation to an existing manufacturing line. Cart-style automatic guided vehicles (AGVs) are the primary materials handling technology that moves the carts from one assembly station to the next before delivering them to an electrical verification station for quality control and finally to a queue where the completed cabs will be delivered to the next step in the tractor assembly process.

The system is simple and efficient. Here are the steps.

The process begins when a welded and painted cab frame enters the cab production area and is staged in an area known as the Mouse Trap (1). From here, the cab will enter the assembly line where large modular subassemblies will be installed. While every cab will go to certain stations along the line, a cab may also be diverted off the main line to workstations where optional features and equipment will be installed to customize the cab for a customer.

At the Mouse Trap (1), the cab is on a specially designed skid. When the AGV moves under the skid, a pin connects the skid to the cart. That marries the cab frame to the AGV. During that process, an operator scans a serial number on the cart that will be transmitted to the manufacturing system and stored on the mouse to identify that cab during production.

From the Mouse Trap, the cab enters the assembly line (2). During its trip down the line, the cab can visit 12 assembly stations (3), such as the back panel, roof, seat, front control support, glass and fender stations. When an AGV pulls into one of the assembly stations, it communicates the serial number to a programmable logic controller (PLC) in the department. With that information, the system communicates the work to be done at that station to the operator. As the operator completes the steps associated with the process at that station, data is automatically collected and updated in the production system.

Overhead tooling has been outfitted with homing sensors. Before the AGV can move forward to the next station, the tooling has to be returned to a “home” location.

Once the work is complete and tools are safely out of the way, the AGV moves to its next stop. Once the final subassembly or option has been installed, the cab is delivered to an electrical verification station (4) for a quality control check. From there, it will be delivered to a staging queue (5) where it will be picked up and delivered to one of two assembly lines.

The final assembly system notifies the cab line when it is ready for a specific cab. At that point, the operator releases the cab and its skid from the AGV. The cab moves on to the assembly line and the AGV travels along an AGV return path (6) back to the Mouse Trap (1) where it will pick up the next cab skid.

John Deere: Nothing runs like an AGV
On its Iowa manufacturing campus, John Deere is using AGVs to move tractor cabs down the assembly line. The result has been savings in labor, a safer work environment and improved quality.