Robots run the warehouse
They’re not for every distribution warehouse, but robots are demonstrating efficiency in large operations
By Dick Friedman
In a previous article (“The People-Less Warehouse,” May/June 2012) we looked at automated equipment for storing and moving items in a warehouse, but nothing like the robots that AmazonSupply will be getting from Kiva Systems, a company it purchased in early 2012. (This article does not specifically describe Kiva robots; there are other manufacturers, and the list of them keeps growing). Yet a few high-cube, high-volume warehouses use robots to put away and pick items, and aggregate items for shipping. Developed and nurtured for repetitive-task, high-volume manufacturers, the use of robots and automated equipment in warehouses is in the very early embryonic stage of utilization. But it is the wave of the future; another step toward the almost people-less warehouse. Before looking at the details of warehouse robots, let’s take a brief refresher look at the automation described in the previous article.
While contemplating the use of automation of one degree or another, remember that proper warehouse organization, and procedures and controls that are followed, are the foundation for effective operations. The less automation that is involved, the more the need for organization and discipline.
AUTOMATED NON-ROBOTIC EQUIPMENT - is equipment for storing, retrieving and moving items, but equipment that cannot be programmed.
Conveyor. Examples are powered belt and powered roller conveyors that move items or cartons or reusable containers, horizontally or downward or upward. Manual roller conveyors are un-powered; if horizontal, people push things along; if it slopes downward, things move under the force of gravity. A conveyor can be loaded manually or by some other equipment or a robot.
Sorter. This machine either directs something to one of several conveyors, or drops something into the proper carton. A sorter can be loaded manually or by a conveyor or by a robot.
Automated Storage and Retrieval System (ASRS). Think of a row of shelves and a driver-less lift truck that runs parallel to the shelving, controlled by signals coming from wires buried in the floor. Software controls the lift truck, directing it to the system selected (by other software, based on the item’s bar code or RFID chip) bay and slot; then directing it to the designated level, where the pallet is eased by the forks into the storage slot. For picking, the process is reversed. There are other kinds of ASRS devices, such as a carrousel.
Automatic Guided Vehicle (AGV) – typically a battery-powered low-height motorized platform that follows wires buried in the warehouse floor. The wires can be located in one or more aisles, so an AGV can travel throughout a warehouse. A pallet, carton or piece is literally taken for a ride. Special software determines the exact path taken when putting away or retrieving something.
ROBOTIC EQUIPMENT. A robot does not look like a person. Some warehouse robots look like a box on four wheels, with recessed metal “arms” that can extend out and grab around or under a carton, and pull out the carton. Other robots look like a pole with articulated arms that can grab, lift and maneuver boxes. Unlike the automated equipment described above, a robot can contain vision technology that enables it to “see” the shape of something to be handled (even in low light), and if needed, adjust its speed, direction, etc. And a robot can contain “touch” technology that can sense irregularities or problems with an item, and cause the robot to adjust its “behavior.” Each robot communicates wirelessly with a central computer, that provides basic direction to it (at times, based on feedback from “seeing” and/or “touching” something), and that also controls automated equipment, and integrates and coordinates the actions of the robots and automated equipment.
A robot that picks can retrieve a box or piece, and place it on a conveyor or sorter, as commanded by the central software. The latest picker robots can pick and place 100 lb. boxes in a few seconds, and do so almost 24x7 – time is usually scheduled daily for preventive maintenance. A robot that loads can use its arms, vision and central-software-directions to aggregate boxes to a pallet, orienting each box so as to obtain a profile that will not cause problems down stream, such as at an automatic shrink wrapping machine. One box per few seconds, almost 24x7. The pallets may be placed on a conveyor that takes them to a truck, or on a forklift that is driven by a human – one of the few left in the warehouse.
Robots can be individually programmed, so that if more are needed to perform a peak-load task (such as unloading trucks), only a few minutes are needed to re-program the ones needed. When another kind of peak load task arises, such as picking, a quick reprogramming of needed robots results in different skills. As product sizes and weights change permanently, robots can be re-programmed to handle the new requirements.
Multiple robots can work very close to each other, without slowing down. In one warehouse, a multiple-mezzanine arrangement enables several robots to simultaneously work on each level; picked items are placed on a dumb-waiter-like elevator for movement to automated equipment or another robot.
Hypothetical system. Let’s look at how robots and automated equipment could work together in a warehouse. At receiving, manned forklifts are used to move pallets from inside trucks to a powered belt conveyor; at the end of the belt, a sorter determines which secondary conveyor belt to use. At the end of a secondary belt, a robot grabs a box, reads its bar coded or RFID information, transmits that information to a computer, and follows directions from that computer as to where to put away the item. Think of a line of closely spaced robots, each grabbing a box from a secondary belt, and putting it away. Similarly, a line of several robots would pick items from one or more locations in the warehouse, and place them on a conveyor or sorter that feeds other conveyors.
Software. The previous article described three kinds of software that can be used in a warehouse utilizing automated equipment. Here is a summary of two of them, updated to reflect the involvement of robots.
Warehouse Management System (WMS) is software that plans and manages the arrangement and activities of a warehouse. For example, determining where to store items to be received the next business day, based on purchase orders and customer orders data; after items are received, determining where to store an item; tracking how much of each item is stored in each slot. A WMS also does higher-level labor planning (e.g., how many people to bring in for a particular day and shift). Most WMS functions do not work in real time, however, as soon as data about a picked item is captured, the WMS updates slot-specific and item-level data. The WMS also interfaces to systems of vendors (e.g., receives advanced shipping notices).
Warehouse Control System (WCS) is software that controls the physical activities of automated equipment and robots; such as starting and stopping conveyors and sorters, directing a robot to perform a specific task at a specific location. A WCS works in real time, using both data it acquires (e.g., status of a piece of equipment, and from reading a bar code on an item/carton) and data transmitted by the WMS.
A WCS also can control the speed of a particular unit and robot, in order to balance loads on specific equipment/robots and through the warehouse. And it also makes real-time adjustments. For example, when a jam at a sorter is detected, the WCS would stop those upstream activities that would result in other jams.
A WCS also assigns and manages labor (when a packer logs out, the WCS will determine which other suitable people are available, and assign the function to one of them).
Pros. Obviously, robots, like automated equipment, reduce warehouse headcount and related costs. Less obvious, robots eliminate back injuries caused by constant lifting of heavy items, or even lightweight items. No need for rest breaks, and no worry about turnover amongst warehouse workers. Not obvious is that the use of robots can dramatically decrease the amount of warehouse cube needed to store a given set of items/cartons/pallets; think of the mezzanine arrangement described previously.
Although not as flexible as humans, modern programmable robots are much more flexible than automated equipment, which is designed for a particular mix of product sizes and weights. This limited flexibility is one reason that automated equipment has not exactly set the world on fire. Speaking of humans, robots do create high-paying warehouse jobs – people are needed to program robots, as well as maintain them and watch them in case something goes wrong (like a case is dropped).
Cons. Of course, the cost of the robots and the warehouse environment needed for them to function effectively is very large. It’s all custom-designed and constructed. Yet, as the cost-effectiveness of technology advances, the costs for the robots is decreasing at a rapid rate.
The future of robots is perhaps best indicated by a California-based robot research firm that devises strategies and plans for companies that build robots, or want to use robots.
How to Get Ready for Robots
It’s going to be a long wait for 99.99% of distributors, so act now to reduce warehouse costs and prevent costly mistakes. Some improvements can be done quickly and at little or no cost. Look at the warehouse organization, procedures and controls.
Dick Friedman is a recognized expert on warehouse operations, management and technologies for fastener, tool, industrial and MRO distributors. He is a Certified Management Consultant and is objective and unbiased, so he does NOT SELL warehouse management systems or technologies. Dick applies more than 30 years of experience to help distributors reduce warehouse mistakes and costs, often through quick, inexpensive changes to operations, management or technology. Call (847) 256-1410 for a FREE consultation, or visit www.GenBusCon.com for more information or to send an e-mail.
This article originally appeared in the May/June 2013 issue of Industrial Supply magazine. Copyright 2013, Direct Business Media.
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