How Toyota automated the delivery of parts and subassemblies

Automatic tuggers and carts are moving materials once handled by conventional industrial trucks.

By ·

Toyota Motor Manufacturing, Kentucky; Georgetown, Ky.
7.5 million square feet, including 1 million square feet using AGVs
Products: Camry, Avalon and Venza models; AGVs handle raw materials, subassembly components and in-process subassemblies
Throughput: 500,000 vehicles and engines per year; AGV system transports more than 1.8 million parts per year
Employees: 6,600 total
Shifts per day/days per week: 2 shifts per day, 5 days per week plus overtime as required

The system at Toyota Motor Manufacturing, Kentucky’s, or TMMK, manufacturing plant brings together automatic guided tuggers (AGT) and automatic guided carts (AGC) to create a lean and efficient subassembly production system.  (Read about how and why TMMK improved production processes.)

The tuggers are used to deliver raw metal components and stamping parts to robot processes. The resulting subassemblies are then delivered by the carts to the production line.

In all, there are 22 automatic tuggers and 79 automatic guided carts to handle a variety of subassemblies. The plant also has four conveyor-top AGVs to move shell body parts in a separate process.
Regardless of type, the automatic vehicles are directed by a sophisticated traffic control system that monitors the location of all of the vehicles in real time. Automatic tuggers and carts navigate by following a magnetic tape path that is embedded in the floor. This prevents the tape from being damaged by lift trucks pushing pallets at floor level.

RFID tags programmed with location coordinates are also embedded in the floor. Meanwhile, each vehicle is equipped with an RFID reader. This allows the traffic control system to monitor the location of every vehicle in the facility in real time: When one of the vehicles passes over an RFID tag, the signal is read by the reader and the location of that vehicle is broadcast to the traffic control system.
That allows the system to prevent accidents. For instance, if two vehicles come to an intersection at the same time, both will come to a stop. The system will then give one of the vehicles the right of way to proceed through the intersection.

To initiate a production process involving the automatic tuggers, a team member pushes a start button at a workstation. That signals the traffic control system to deploy an AGT to either the Circle G AGV Pick-Up location (1) where raw components are stored or to an In-House AGV Pick-Up location (2) where stamping parts produced in the plant are stored. The tugger pulls a string of empty carts that will carry the payload.

Once the AGT arrives at one of the two pick-up locations, totes are loaded onto dollies and the dollies are loaded onto the empty cart. When that process is complete, a team member releases the AGT.

The automatic tugger then delivers the cart to an Automatic Tugger Drop-Off location in an area referred to as Spaghetti Junction (3). This area is located just less than 600 meters from the Circle G area. In fact, two automatic tuggers and dolly sets will arrive at a staging point just behind a drop-off location.

The parts feed robot processes in workstations (4) located on either side of Spaghetti Junction. Once the team member is ready for parts, one of the tuggers will advance into position for the team member to unload the totes from the dolly and begin the production process using those parts. When all of the parts on the dolly have been unloaded, the tugger returns to the Circle G picking area (1) or the In-House Pick-Up location (2) to pick up its next payload.

Once a subassembly is completed at a workstation (4), the automatic guided cart comes into play. Completed assemblies are loaded by hand or by a robot into a flow rack. The rack, in turn, is picked up by an AGC. The automatic guided cart will deliver it to the next workstation (5) in the process, where it will be installed into the body of a vehicle.

Other assembly processes take place in work areas located in that part of the plant (6).

System suppliers
System integrator: Industrial Concepts
Automatic tuggers: Toyota Material Handling U.S.A.
Conversion kit for tuggers: AutoGuide Systems
Automatic guided carts: Creform
Automatic guided vehicles: Shintec Hozumi
Industrial carts: Developed in-house by Toyota Motor Manufacturing, Kentucky


About the Author

Bob Trebilcock
Bob Trebilcock, editorial director, has covered materials handling, technology, logistics and supply chain topics for nearly 30 years. In addition to Supply Chain Management Review, he is also Executive Editor of Modern Materials Handling. A graduate of Bowling Green State University, Trebilcock lives in Keene, NH. He can be reached at 603-357-0484.

Subscribe to Modern Materials Handling Magazine!

Subscribe today. It's FREE!
Find out what the world’s most innovative companies are doing to improve productivity in their plants and distribution centers.
Start your FREE subscription today!

Latest Whitepaper
Hydrogen, the Future of Materials Handling
Large, successful organizations are integrating hydrogen fuel cell technology into their lift truck fleets and benefiting from lower operational costs, reduced emissions and improved reliability.
Download Today!
From the October 2016 Issue
Brownells’ new Iowa distribution center has taken touches—and miles—out of the order fulfillment process and increased throughput with near 100% accuracy.
System Report: Brownells new DC is flexible and responsive
Pallet Usage Report: Pallets Remain Critical in the Modern-Day Warehouse
View More From this Issue
Subscribe to Our Email Newsletter
Sign up today to receive our FREE, weekly email newsletter!
Latest Webcast
Pallets: Supporting Product, Processes and the Enterprise
The smallest leak in performance or cost can bring a lean, nimble and speedy supply chain to a halt. During this 30-minute webcast we'll examine how Modern's readers use pallets to keep the wheels turning as they maneuver a road filled with sharp edges and potholes.
Register Today!
Brownells: Designing for Efficiency and Growth
Brownells’ new Iowa distribution center has taken touches—and miles—out of the order...
Industry celebrates National Manufacturing Day
Fourth annual Manufacturing Day is a grassroots effort by U.S. manufacturers to improve the public...

American Eagle Outfitters’ omni-channel journey
The fashion retailer has used warehouse execution software and automation to create a true...
The data-driven lift truck
Now that manufacturers and distributors are using the data from their automated systems to drive...