Automated guided vehicles (AGVs) have helped manufacturers optimize facility logistics for over 50 years. Yet, despite its long history in industrial manufacturing, AGV technology remains a mystery for many of today’s industry leaders. This article will cover the basics of AGVs, their applications, comparisons to other mobile robot technologies, and help you determine if they could be suitable for your application. 

What are AGVs?

AGVs, as their names suggest, are unmanned, self-propelled, mobile transporters. Most AGVs resemble small-to-medium-sized carts, dollies, or forklifts. Common types of AGVs follow magnetic or colored strips along the facility's floor to navigate. However,  as we will discover later, other types of AGVs offer different navigation methods. AGVs are often deployed in various logistics applications to help manufacturers transport material efficiently.

How do AGVs Work?

AGVs often have simple tasks that can be generalized as point-to-point motion. They usually have a starting point where they wait for a signal or instruction. Once that signal is received, they move to another location. AGVs are fitted with various sensors and hardware to navigate complex facilities. We’ll discuss different sensing methods in the Types of AGVs section.

AGVs feature software packages that allow for machine control, and status updates and fleet management systems are available for even more complex systems. Examples include fleets consisting of multiple AGVs. These control systems determine AGV behavior, such as load balancing and charging. In addition, they often handle how AGVs communicate with other systems in the facility such as other machines and warehouse logistic software, for example.

Types of AGVs

The types of AGVs are defined by their sensing mechanism to navigate their environment. This is a crucial consideration when researching AGVs because they offer their own benefits and shortcomings.

Magnetic Guide Tape

Magnetic guide tape types are the most common AGV. There are a few reasons why this option is so popular. First, mag-guided AGV technology is a cost-effective option due to the simplicity of the hardware required. Simple induction sensors and magnetic tape are essential navigation tools, which can be low-cost compared to more expensive navigation technologies. 

Additionally, routes can easily be reconfigured by removing the old tape and applying new tape on a different path. This is a cost-effective method for rerouting compared to other methods. Magnetic tape is also useful for dirty environments. However, these types can struggle in environments where ferromagnetic particles or shavings can be present. These materials include iron, nickel, cobalt, and associated alloys common to the metals industries. Tile manufacturing facilities provide a challenging environment due to dirt and dust. Magnetic tape-guided AGVs can still perform due to their resistance to non-ferromagnetic contaminants.

Colored Guide Tape

The simple colored tape-guided type is another standard navigation method. This type shares many similarities with the magnetic tape-guided types. Routes can be easily reconfigured by reapplying the navigation tape. Sensing hardware includes simple vision systems that identify the specially-colored tape. 

These AGVs can struggle in dirty environments where the colored tape can be obscured, and the sensor lens can become dirty. Particularly dusty facilities might opt for a different type of AGV to overcome the shortcomings of vision-based navigation. Sterile facilities like medical and electronic manufacturing plants can leverage their clean environment by using colored tape-guided AGVs. These models can perform without risk of track obstruction due to contaminants.

Wired Navigation

Wired navigation refers to AGVs that follow thin wires embedded in the facility's floor. These wires transmit radio signals via onboard antennae.  AGVs of this type maintain their performance in dusty or dirty environments. They are another low-cost option for those looking for cost-efficient AGV solutions. Example environments include wood mills, tile facilities, and brick plants.

However, these AGVs are not as easy to reroute, as new floor slots must be carved out for new paths. Additionally, due to their radio-based navigation, areas of high electromagnetic resonance can affect transmissions. 

Laser Navigation

Laser navigation is achieved using laser transmitters, receivers, and reflectors mounted on the AGV and its path. Time-to-target calculations are used to determine position within the facility. In addition, the system can modulate the speed and direction of the AGV based on the information it receives from the transmitter-receiver. 

These systems operate well in dynamic environments as the reflectors and receivers can easily be rearranged to suit the facility's needs. They offer quick installation and high accuracy but can be more expensive than tape or wire-guided options. Furthermore, they could suffer in dusty environments or scenarios where their line of sight might be obstructed. Beverage plants, logistics facilities, and pharmaceutical manufacturers can make use of laser-guided AGVs thanks to their cleanliness. 

AGV Applications

As previously mentioned, AGVs are applied in logistics tasks. Manufacturers use AGVs to transport parts and products from one location to another. Let’s discuss some more common applications in more detail.

Material Transport

AGVs assist between processes by moving parts from one location to another. This can include:

• Machine to Machine Transport
• Machine to Operator Transport
• Operator to Machine Transport
• Machine to Warehouse Transport

AGVs operate as a middleman in this application by transferring material between processes. Take a food and beverage application as an example. After being palletized, packaged water bottles need to be moved out into warehousing for storage. AGVs can handle this automated process and keep human workers in positions where they can make more complex decisions around arranging the pallets once the AGV delivers them to the warehouse.

Order Picking

AGVs are highly impactful for order picking. Over the long term, order picking can stress human bodies and result in errors. Order picking tasks can be either partly or fully automated with AGVs. Partial automation results in a hybrid task with human technicians picking while the AGVs transport the products. Fully automated operations allow the AGV to perform the picking and the transportation.

The decision to fully automate revolves around how you could most optimally deploy human capital, how ready you are to invest in a fully automated solution, and the complexity of the picking task. For example, complex 3D picking tasks like pulling an exact number of small, numerous parts from a bin can be a challenge for fully automated solutions. Fully automated solutions can include mounted robot arms and special bin systems to enable part dispensing. Understanding how your operators will interact with the AGVs is critical in deciding your level of automation.

Are AGVs Right for You?

Think about various tasks your operators perform around the facility. You might be surprised to find out how much time is spent transporting goods from one place to another. AGVs offer to do the transporting for you. This enables your operators to remain on-task in more complex job duties. Let’s look at some signs that an AGV might be a need for your facility. 

You Need to Reduce Logistics Accidents

The injury rate for warehouse workers is double the national average in the United States. Logistics tasks are dangerous. Manufacturers often decide to automate some logistics tasks solely based on safety. While no solution is 100% safe, AGVs come equipped with an array of safety equipment. Safety laser sensors, auditory and visual signals, safety bumpers, and speed controls are standard risk mitigation equipment for AGVs. Human operators are prone to dangerous actions due to stress and fatigue. AGVs are designed to operate by constantly monitoring their environment with their sensor arrays. They are a safer option for modern manufacturing. 

You Need to Increase Throughput

Looking for ways to increase throughput should include reviewing your logistics operations. Transportation requirements often create bottlenecks in manufacturing facilities. It’s often apparent how time wasted traveling takes operators off-task for significant amounts of time. This time off-task adds up throughout the day and compounds when subsequent processes are delayed. AGVs can handle transportation while operators keep the line production at an optimal rate. 

Important Considerations

There are some final considerations for manufacturers considering AGVs for their facilities. 

• Standard AGVs are battery-powered. Do you have suitable locations for charging stations?
• For Wi-Fi-enabled AGVs: do you have a suitable Wi-Fi signal throughout the AGV’s proposed work zone?
• What challenges in your facility could create problems for AGVs (dirty environment, metal shavings present, high resonance or electromagnetic interference, etc.)?

Considerations like these help determine which AGVs are the best for your facility. Automating your internal logistics operations can have an impact that unlocks optimizations around the facility, but it can be hard to take the leap. That’s why it’s essential to compare possible solutions before buying.

The HowToRobot digital platform makes it easy to explore the market and receive multiple offers from suppliers. We can help you articulate your needs risk-free and anonymously, leading to streamlined interaction with suppliers ready to provide you with solutions to help your specific situation. Contact us today to get started.