Although automatic guided vehicles (AGVs) are not new in factory operations, Panasonic Factory Automation Co. (Franklin Park, IL) personnel think that there is a revolution-in-becoming so far as this material handling equipment is concerned, especially in automotive-related applications, whether it is for electronics assembly or transmission production—or something in between.
Ray Katchmar is responsible for introducing new Panasonic automation equipment to the U.S. market. In many cases—such as is the case with AGVs—this is equipment that has been utilized in Matsushita operations prior to becoming commercial products. In other words, it has been proven in the real world (and you can't imagine that, say, the VCR manufacturing people within Panasonic would be any happier than you would be if you had several of the AGVs that weren't doing what they're supposed to).
|Compact AVG From Panasonic.|
Katchmar says he'd spent a good part of this past Spring visiting an assortment of prospective users for the AGVs. The units had their public debut at the 1999 International Robots & Vision Show in Detroit in May. And what Katchmar discovered by talking to a variety of people is that while they are familiar with AGVs, it's the applications for the equipment that tend to be less well understood.
So far as the Panasonic equipment lineup goes, the two main applications are (1) moving parts and materials and (2) moving subassemblies from workstation-to-workstation.
One objective of the AGVs—called "Panawagons"—is to reduce the need for people to go walking through a facility. For example, say there is a need for parts replenishment at a workstation. It may be that the station operator has to go after those components. As that person is out of position, there is output lost from that station. Chances are, that person, as s/he goes through the plant, will visit with people at other stations, which could degrade the output from those stations, too.
Or, take the subassembly approach. Katchmar cites the cases of manufacturers of instrument clusters and wiring harnesses as examples of instances where it is common for product customization, which means that the subassembly and/or people are moving from station to station—and not always the same stations. Once again, this can lead to inefficiency unless appropriately arranged.
In both cases, AGVs—programmed to retrieve and deliver parts or to transport subassemblies—can be the solution to greater operational efficiency.
Another issue that AGVs address is plant layout. Because the devices travel along paths that are defined either by tape affixed to the floor or through radio frequency (RF) guidance, there aren't the fixed conveyor structures separating sections of the plant. This is not only beneficial with regard to moving through a facility (no conveyors in the way), but AGVs can provide space efficiency (the amount of space they take up is their footprint).
What's more, when it is necessary to modify the process flow (due, say, to a process design change), the AGV path can be rapidly reconfigured (i.e., move the tape or reposition the RF units).
One benefit that Katchmar says company management (not to mention the workers) is appreciative of is that by having the motorized vehicles toting parts rather than people, there is a reduction in injuries from picking up too-heavy items or from accidents with carts or other vehicles (the AGVs have a contact safety bumper, a non-contact collision-prevention sensor that slows when an object is approached and then completely stops the unit when the distance is too small, a musical alarm that plays while traveling, and a flashing light, so the likelihood of getting hit by an AGV are slim for anyone paying attention, and with the light and the calliope-style music, paying attention isn't difficult).
Among the Panasonic AGVs (there are two main types within the lineup: towing and conveying) is the C55S. The unit is 885-mm long, 550-mm wide, and 260-mm high. It has a 400-mm turning radius. It has a rated load capacity of 227 lb. As many as 256 travel patterns can be stored in the Panawagon's memory. And this front-wheel-drive unit can really move: it is rated at 60 m/min.
One interesting unit is the Panawagon E Series. Fundamentally, there is a drive unit and a control unit. These are both compact, with the former measuring 310-mm wide, 385-mm long, and 210-mm high; and the latter: 271-mm wide, 400-mm long and 130-mm high. The front-wheel-drive unit is capable of traveling at a maximum 40 m/min; there are 16 possible speed settings within its range.
The interesting part is that the E Series features an open-platform architecture. The drive and control units can be set up to produce an AGV that meets application needs. For example, it would be possible to construct a series of these units with, say, part fixtures on the top of the platform.
As the demands for flexible production increase, AGVs may become more important in the material handling architecture.—GSV