Customer's Requirements
Hexcel Manufacturing, a manufacturer of honeycomb panels, needed conveyor systems and pressing equipment to convert raw material to a finished product. This system had to have the ability to move raw material to 15 presses for consolidation, and move the finished product to packaging.
The customer wanted a system using modern technology that would be its showcase into the future. System requirements included versatility, reconfigurability, reliability, low noise levels, space savings, increased speed, low maintenance, and cost savings.
Solution
For this customer Ward Systems introduced the PowerPallet, which could meet all their requirements and more. Ward Systems built the presses and the conveyor systems to optimize movement from raw material to the presses and then on to packaging.
PowerPallet Concept
Basically, we reversed the formula used in typical conveyor systems and motorized the transport pallets, leaving the conveyor inert. This means that the conveyor is just track that the pallets drive on between locations, with no active device installed on it. The PowerPallet provides all of the functionality necessary to move products from point to point. Like miniature AGVs, these self-contained, radio dispatched vehicles provide rapid quiet movement of products and materials in a smoother, more energy efficient way than conventional conveyors.
How It Works
The PowerPallet is a low rectangular box that has axles with wheels bordering each of its four sides. Two axles at a time are in the down position, with wheels contacting the riding surface, while the other two axles are retracted. This allows travel in the X or Y direction. To change direction, the PowerPallet switches axles and simply goes forward or reverse in the next direction. A Power Pallet can travel through many intersections before stopping at the one needed to change direction: an onboard RFID reader reads tags on the system to locate the correct intersection at which to stop. The PowerPallet's built-in stop is used to stop precisely at intersections, or to lock in place at workstations to provide a stable work surface for the operators. The PowerPallet uses batteries to drive its motors and power its systems. The batteries are opportunity charged at workstations or accumulation lanes, providing uninterrupted service throughout the production day.
The entire system is controlled by a main controller, which performs two major functions. First, it interfaces with automated equipment and operators on the line to dispatch pallets to or from these locations. Second, using Omron's Wireless Device Net, it communicates with the PowerPallets to act as a dispatcher and traffic supervisor, optimizing traffic flow and preventing collisions.
Application Advantages
The PowerPallet can take different paths to the same destination, depending on traffic flow. Coupled with its inherent ability to go forward or reverse, this capability affords greater application flexibility, greatly improving the end user's functional layout. In conventional conveyor systems the layout has to be carefully thought out to determine where to place reversing sections verses one-way sections. This can greatly affect initial system cost, and changes after the fact can become extremely expensive to implement. The PowerPallet, on the other hand, can automatically go forward or reverse anywhere in the system, anytime it is needed, with no cost impact.
System installation is easy: just cut and assemble. When production needs change, future reconfiguring of the line is just as simple. Because all the power and controls are in the PowerPallet, we skip the cost of labor and materials required to connect the myriad of motors, valves, cylinders, and sensors used in traditional conveyor systems back to large control cabinets.
We're not just talking distributed I/O -- we also have distributed intelligence. Software for a PowerPallet system is easier to implement because the PowerPallets have all of the intelligence necessary to provide meticulous timing and control for complete movement throughout the system. A simple destination command is all that is necessary for even the most complex move.
Finally, the PowerPallet dramatically reduces downtime and support requirements. Each PowerPallet has the same components typically found on a normal conveyor system, such as motors, sensors, and bearings. Any of these components can and do fail on all conveyor systems. Because it's easy to physically remove a PowerPallet from the production line, single-point failures that can bring traditional systems to a grinding halt are avoided. Typical conveyor systems run their drive motors continuously, wearing components and consuming power. The PowerPallet is an intermittent device, so the motor runs or bearing turns only when the pallet is actually doing its job.
