Integrating AGV Systems
We have a big batch of acronyms for everyone today while we discuss Automated Guided Vehicles (AGVs), Automated Storage and Retrieval Systems (ASRS), Warehouse Management Systems (WMS), Supervisory Control and Data Acquisition (SCADA), Manufacturing Execution Systems (MES), and probably a few others.
By the end of this post, you’ll understand what each of these technologies are, how or why you would want to use them, and how to integrate them with your plant automation and business systems.
What is an AGV?
An Automated Guided Vehicle (AGV) is simply a motorized vehicle, usually reminiscent of a forklift or electric pallet jack that can move items from point A to point B. Generally, AGVs move along a pre-defined route.
While there are many AGV types and navigation methods on the market, they all use some form of sensors and signals to tell the AGV where it is in the space, where it needs to go, and how to get there. It might be as fancy as a computer vision system which builds a real-time view of the plant with obstacle detection and collision avoidance algorithms, or it may be simply a wire or coded tape on the floor defining a more static route.
Typically, the AGV will have a mechanism to load and unload material. It may be similar to a fork truck with a few inches of lift, a set of rollers that can accept trays from an existing conveyor system, or as complex as a robotic arm with a sophisticated pick and place operation.
Once AGVs are in place, the next step is to tell them which material they need to get, where it is now, where it needs to go, when it needs to get there, and how it gets there.
What About WMS?
The first integration most companies will do with an AGV system is to connect it with their Warehouse Management System (WMS). This integration will give visibility into the materials on hand, where they are in the facility, and how much of any given material is in a location.
Your WMS will likely already have an interface built in, so as a bare minimum integration you would create an SOP (Standard Operating Procedure) to deduct material from the warhouse when it is removed from a location and placed on an AGV. Then it will be added to location when and where it is unloaded from an AGV.
Think of the AGV as a forklift driver, and you are giving them pick lists. You will either manage storage in such a way that the AGV can pick up known quantities on pallets, or have someone who picks material and places it on the AGV. Then, when the AGV is full, or is ready to move that material to the next location, it finds its way there, gets unloaded or unloads itself and moves onto the next location.
The AGV API
Even if you are doing just a basic WMS integration, you will need to tie into the AGV system's API (Application Programming Interface). The API is required for sending the AGVs information on where they need to go, what they need to grab, and when they need to do each task. Depending on your AGV supplier, this will either be a stand-alone interface to manage these tasks, or API endpoints you can use with other software packages to send information back and forth to the AGVs.
Your AGV system will have documentation on how this system works. While the specifics will be different, the general concept is that you will send information to the API (including work order numbers, pick and place locations, type of AGV required for the operation, desired routes, and a schedule). Then, the API will interface with the AGVs themselves telling them what to do and when.
The system may be simply an operator entering tasks one at a time throughout the day, or complex including a production schedule—enabling just-in-time manufacturing concepts like KanBan to manage resources when and where they are needed anywhere in your facility—or any level of complexity in between.
What is SCADA?
Supervisory Control and Data Acquisition (SCADA) systems are the brains behind most manufacturing operations. They connect PLCs and field devices with each other, giving the operator a Human Machine Interface (HMI) they use to control and monitor the process. SCADA systems generate alarms, store data for historical trending and reporting, and give you full visibility into your operation in real-time.
SCADA systems can be a very powerful tool when integrated with an AGV system. Operators can manage AGV task assignments, or AGV tasks can be completely automated when operators are already selecting work orders or parts on the SCADA system as they are running the process. The SCADA system can also connect to the AGV alarming backend, displaying any AGV alarms to the operator in real-time.
Operator notification features are generally built into SCADA systems. So, you could get data from the AGV system and send alerts to your operators based on AGV conditions. For example, if parts are running low at a particular workcenter, alert the operator that an AGV has already been notified and is on its way. If an AGV is stuck for some reason, you could get an alert immediately to resolve the issue. Or, if the AGV needs to be charged or needs maintenance, this can easily be brought to the operator's attention.
Integrating AGVs with SCADA systems is a great first step, and will give you the ability to manage the AGV system in real-time. But, what if you want to monitor the overall efficiency of the AGV system?
Enter MES + AGV
To track the efficiency of your AGV system, you can easily integrate it with a Manufacturing Execution System (MES). This will let you track Overall Equipment Effectiveness (OEE), overall performance, throughput, downtime, integrate with track and traceability systems, use more robust detailed work order integrations, work order instructions, and even schedule or optimize routes using SPC algorithms.
If you are familiar with MES systems, you will understand some of the capability possible with an AGV integration. If you aren't, please check out our thorough MES guide that goes into a lot more detail with MES system features and functionality.
Basically, MES helps you answer these questions:
How well is my AGV system running?
How can I make it run better?
MES also helps you streamline your overall business system technology by integrating scheduling tools, read/write data access with your ERP system letting you handle AGV tasks based on customer orders and shipping/receiving requirements, and even integrating with Work Order Instructions to give operators real-time information on how to load an AGV when they are working with unfamiliar materials.
What is an ASRS?
In large facilities with many warehouse areas or a large geographic footprint you might see (ASRS) Automated Storage and Retrieval Systems. These act as "mini" warehouses inside your facility. Commonly used consumables might be stored in an ASRS to limit the amount of time an AGV spends going from the plant floor to the warehouse to get material. They can be used for in-progress parts as a staging area for production lines with multiple operations and differing cycle times. An ASRS also gives you the ability to store items more densely than in typical warehouse situations.
The entire benefit of an ASRS is that it is automated. You don't need to worry about how items get into and out of it, there’s a mechanism to load/unload material which is easily facilitated by AGV systems. Once items are in the ASRS, information about their location and lifespan is stored in a database. Both the information and the items can be easily retrieved from the system using the automation controlling the ASRS.
You might not need ASRS—but if you do, it can have a huge impact on your overall productivity.
Packaging Integrations
AGVs can also work well with packing systems such as palletizers—loading them and unloading them once wrapping has been applied. Depending on your process and workflow, AGVs might save labor hours for a forklift driver who would otherwise have to manage the palletizing machines.
Unless it’s not something you do very often at your facility, it may warrant the cost of adding an AGV route to a palletizing machine.
Breaking the 4th Wall: AGV Systems Outside the Facility
So far we have only discussed AGV systems inside a facility. If you are using trucks or shipping containers to ship finished product from your facility, or even unloading containers of raw materials, you can likely use AGVs to automate this process.
While the form factor of the AGVs themselves may need to adapt to your particular environment, many companies offer AGVs for Automatic Truck Loading/Unloading (ATL). This approach can greatly benefit the just-in-time manufacturing concept. By managing raw material as it arrives at the building, or depending on your throughput, even taking material directly off the truck to where it needs to be used next on the line can save valuable time.
Depending on your process, you will likely see more gains by utilizing AGVs inside your facility first. But using them outside the facility is also something to keep in mind as your AGV system—and your enterprise—grows.
Assembling the Building Blocks of Industrial Automation
Corso Systems excels at integrating the various systems mentioned in this post. We have used Ignition by Inductive Automation for all of these integrations in various combinations from just SCADA and AGV, all the way up to a full business system integration. That particular system automatically schedules customer orders on the production line, and manages them through shipping out the door—all while automatically creating all of the required documents along the way.
Updated - 12/27/2022
