7 fresh ways to think about AGVs
Using automatic guided carts (AGCs) as continuously moving assembly lines at an automotive assembly plant offers flexibility in operations.
September 01, 2012 - MMH Editorial
2. For lineside delivery of parts
Many operations are creating kits and pre-assembling components in another part of the plant and delivering these kits and components directly to the assembly line, also known as lineside delivery. “Now we are delivering on demand,” says RMT Robotics’ Torrens. “An AMR goes to the kitting area, retrieves only what it wants, when it wants, in the quantities that it wants and delivers it to the line.“
A similar system involves a customer-designed kitting cart towed by a tape-guided AGV system, showing up at the correct time, at the correct spot on the assembly line with the correct inventory sequenced for production. “It’s all positioned conveniently for the production associate to access,” says Keith A. Soderlund, vice president of sales for Creform. “This leads to gains in production efficiency as well as ergonomic enhancements with a properly designed cart.”
3. As a personal assistant and a runner
Torrens takes the concept of lineside delivery a step further with a mobile robot that acts as a personal assistant to the assembler. As the worker is assembling Part A at Location 1, the robot is already moving Part 2 to Location 2. “The total assembly time in the work cell was previously 14 minutes,” says Torrens. “By using a mobile robot, the cycle time decreased to 10 minutes—a more than 20% reduction.” He dubs this the “repositioning of the value of labor,” letting robots be in an assistive role so that humans can do the more sophisticated tasks of assembly.
He cites another example at a steel plant where sample billets of steel need to be collected by lab technicians from various production lines and brought for testing to a QA laboratory 650 feet away. “Lab technicians cost a lot of money and collecting samples is not what they are paid to do. A robot does the grunt work of collecting and delivering samples, so that the technicians can concentrate on what they were hired to do.”
4. To connect islands of automation
Many operations are still pushing carts or driving lift trucks to and from sophisticated machine cells. However, in one application, carts and lift trucks have been replaced with a system that uses inertial guidance—a tape-free, target-free AGC (Savant Automation) that transports unstable loads of tall, narrow, cartons of paper from a robotic palletizer to a stretch wrapper. “We use a variable drive on the AGC’s deck to slowly accelerate and decelerate the transfer so that the load doesn’t tip over,” says Garry Koff, Savant’s president. “Once it’s on the vehicle, we take it to the stretch wrapper, where it gets wrapped.”
According to Koff, tape-free, target-free AGCs are especially suited for automatically moving material through high-traffic main aisles notorious for wearing down magnetic tape. “These vehicles are slightly more expensive but money is saved with installation and with no tape to maintain.”