Top 6 Trials of Using AGVs for Better Industrial Automation

We hear this as a top concern when we talk to industrial manufacturers worldwide. And since these demands will only continue to increase, industrial automation efforts become even more important for finding new efficiencies while increasing quality.

One way we’re seeing companies address these demands is through driverless transport systems, called automated guided vehicles (AGVs), specifically wireless AGVs.

AGVs are essentially mobile robots that are used in many industrial manufacturing applications, such as food and beverage or automotive, given the ease and efficiency with which they can transport parts. In automotive manufacturing plants, for instance, they can transfer doors or engines from one work station to another.

The Move to AGVs and the Impact on Industrial Automation

The shift from human workers manually controlling lift trucks in production chains to motorized AGVs started more than a decade ago. Now, instead of AGVs being operated with a fixed route through the plant, we’re starting to see even more autonomy as these mobile robots begin to rely on wireless technology to improve productivity further. So what does this mean for industrial manufacturing, especially for complex applications? Big benefits.

Using the automotive manufacturing industry as an example, AGVs can help with:

• Extreme customization. As car and truck manufacturers look to meet the very specific and varying demands of their customers, AGVs make this possible on a large scale. Oftentimes, parts need to be supplied very quickly, and in a precise sequence, to as many as 1,000+ locations within the plant. AGVs make this complex chain of events possible.

• Uninterrupted production. In the highly complex and automated production lines found in many industries, particularly automotive, the smallest hiccup can bring the entire operation to a complete halt – and this downtime is costly. To manage so many different vehicle variants requires extreme precision and quality. AGVs are essential to achieving this uninterrupted production.

• Coverage of a large production area. By adding wireless capabilities to your AGVs, you can reap even more benefits. Wireless AGVS can connect many WLAN clients and access points over a very large area to build a single WLAN network – an increasing necessity in automotive plants.
  
  

The Six Challenges Wireless Brings to Industrial Automation

While wireless enables many benefits for AGVs, there are several challenges that need to be considered when building a WLAN infrastructure. These include:

1. Wireless Network Speed

The speed and performance of the overall wireless network can be impacted by a larger number of access points and clients deployed at the site. For instance, often there are up to 200 AGVs in a production plant, coordinated via one network, each one extracting resources from the system.

Many WLAN devices hold the connection until it becomes slow or unstable or even breaks. This results in a slow data rate and can lead to considerable delays of the entire WLAN network.

What you can do:

• Select devices that meet IEEE’s 802.11n/ac wireless standard to enhance the speed of your network. Depending on the configuration, you can achieve an aggregate speed of up to 867 Mbit/s.
  
  
• Integrate Multiple-Input-Multiple-Output (MIMO) antenna technology. With multiple antennas, you can achieve interference-free transmission of multiple signals on the same frequency for higher signal availability and higher data rates.

As manufacturers look to meet the very specific and varying demands of the auto industry, AGVs make this
possible on large scale.

2. Wireless Roaming

Poor roaming performance of a wireless network controlling an AGV fleet often affects operational productivity. These applications require very low (usually milliseconds) handover times. With standard WLAN devices, the connection between clients and access points needs to reestablished every time an access point change occurs. This can cause delays and possibly leave an AGV at a standstill for too long.

What you can do:

• Find products that utilize a fast roaming feature, Opportunistic Key Caching (OKC), to provide fast authentication between several access points in a network and keep AGVs moving on the planned schedule.
  
  

3. High Noise Environments

Wireless devices installed in AGV systems can come in contact with electrostatic discharges (ESDs) from the environment or inrush current from other equipment sharing the same power source. ESDs result in disruption of the wireless connections or, in extreme cases, can even damage the devices.

What you can do:

• Look for state-of-the-art WLAN devices that have built-in radio frequency and power isolators for cost-efficient and safe operation in any environment with electrical interference.
  
  

4. Environmental Conditions

Mobile vehicles, including AGVs, can be constantly exposed to condensation, dust and water/liquids, or to low temperatures, such as in cold-storage warehouses. WLAN clients’ location inside the vehicles causes potential exposure to these extreme environmental conditions and could affect the wireless connection.

What you can do:

• Find WLAN devices with conformal coating to avoid contact with dust, condensation or extended temperature ranges (from -40 ºC up to 70 ºC).
  
  

5. Extreme Shocks and Vibration

WLAN clients are mounted inside the vehicles and, therefore, are exposed to vibrations from all directions. AGVs facing the stress of constant vibrations could become damaged or experience complete failure.

What you can do:

• Choose industrial grade WLAN devices that provide protection against extreme and/or constant vibration.
  
  
• Find devices that comply with the IEC 60068-2-6 standard and have m12 connectivity, which gives the ability to withstand severe onboard vibration and avoid signal loss.
  
  

6. Limited Space

Space is very limited on board the AVGs. In addition, as AGVs are downsizing, more sensors need to be built in. Therefore, the ability to save space is important to integrating WLAN clients onto your AGVs.

What you can do:

• Choose industrial graded WLAN clients with a small form factor to increase your flexibility to locate the device where space is constrained. Many industrial suited client devices are smaller than most cell phones today.
  
  

Where are Industrial Automation and AGVs Headed Next?

While the current state of AGVs is an evolution from being operated on fixed routes to wirelessly controlled mobile robots for more flexibility, smart factories are taking it a step further. Soon, AGVs will no longer be controlled by a central control system as they are now – but will operate completely independent of each other.

This means that smart factories will be able to install an autonomous production line without AGVs needing to follow the fixed, defined time sequence invented by Ford.

In response to this evolution, Belden has joined a consortium, Karis Pro, with several industry leaders, including Audi and Bosch. The project has demonstrated the first instance of a completely enabled fleet of AGVs operating independent from a central control system. The fleet utilizes Belden access points and clients with integrated Parallel Redundancy Protocol (PRP) technology. You can learn more in this video.

In fact, Belden has already developed WLAN devices that are designed specifically to meet the requirements of AGVs. These devices offer many benefits including:

• High wireless speed and roaming performance through prioritized channel scan
• Support of PRP for decreasing network latency and transit time differences to zero
• Firmware with OKC for fast authentication between several access points in a network

If you would like to learn more about wireless technology and how to use PRP with wireless devices, please download our white paper, "Parallel Redundancy Protocol Notably Improves Industrial Wireless Reliability."