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Why Use Rugged Computers for IoT Applications at the Edge

By ·Categories: Industrial IoT·Published On: July 15th, 2020·10 min read·

The IoT at the Edge 

The “Internet of Things” (IoT) and the possibilities for connected devices is exploding. Have you heard about the refrigerator that can send Tweets when you run out of eggs? While it is amazing that we can get real-time inventory updates from the icebox, the fact that IoT has permeated nearly every industry, as it makes data more accessible and actionable, is even more incredible.

MarketWatch reports the global edge computing market will double to $21 billion (€18.7 billion) in 2023, meaning the growth of IoT will push the edge farther than ever before. As businesses realize what they can do and efficiencies gained using the cloud, the need for connected technology in more remote and challenging locations is also increasing.

But first things first…

What is an Edge Computer?

True to its name, an Edge Computer is a computer that is located at the “edge” of an application network, where it usually functions as a server to collect, compute and processes data right where that data is being produced. This could be an IoT application at a food factory for example, where temperature measurement sensors are connected to an Edge Computer so that it can constantly collect the temperature measurements and either act on that data or transfer required information to the Cloud for additional computation or remote monitoring. Edge Computers are available in all sorts of shapes and sizes and they serve an increasingly vital function of putting compute capabilities on-site so that decisions can be made faster and the amount of data being sent back and forth to the Cloud can be minimized.

The Future Location of the Edge

The next frontier of edge computing is often anything but friendly to a computer’s sensitive internal components, which in many instances, will require considerable ruggedization to thrive in these harsh environments.

Take autonomous vehicles for instance, which need to be able to manage, monitor, and respond to thousands of constantly changing variables and conditions in real-time. This requires tremendous amounts of computation locally and we’ve already seen projects where dual Xeon with GPU systems were an absolute must.

But raw performance metrics aren’t enough for these type of edge computing use cases for in-vehicle applications, the amount of shock, vibration, and extreme temperatures the computer will be subjected to must also be considered. And we haven’t even gotten into the intricacies of automotive power, which only specifically-designed systems can handle.

A graphic of edge architecture for autonomous vehicles
This diagram shows how some applications require more compute power at the edge.

This is one of many examples, but it shows the growing need and complexity of putting more compute at the edge where a typical computer doesn’t belong. When pushing farther out to the edge, one thing that’s all too easy to overlook is the environment your hardware will be operating in and what protection it needs to operate reliably.

Enter Rugged Edge Computers

There’s only so much a computer can do when faced with the calculable reality of physics. Extreme temperatures, dust, debris, shock, and vibration – all have been the untimely end of many a PC (may their silicon rest in peace).

Rugged edge computers were developed to survive these threats, and these specialized systems can operate in environments ranging from -40C up to 70C and withstand up to 50Gs of shock force (with some extremely specialized systems rated even beyond that!).

rugged edge computers in NASA rover
The rugged edge VERY far out, in space! Click for more details.

This level of durability is achieved through a combination of mechanical engineering, motherboard design, thermal engineering, and component selection. Simply mashing all that together isn’t enough, though. Everything needs to be tested thoroughly to ensure the overall reliability and performance as a whole, and this testing is not easy on technology, as you’ll soon see.

Mechanical Engineering and Board Design

The board and everything on it is the core piece of any computer, and consequently requires the most protection. Motherboards for rugged edge computers are electrically designed to handle wider power inputs and fluctuations. The board also needs to be able to handle electrostatic discharge, extreme temperatures, and vibration. These protections are achieved through a combination of material selection, vibration damping, and soldered components.

It’s also at the board level where feature sets are established. Because rugged edge computers are often deployed in industrial environments, having I/O that can interface with legacy equipment, receive power from different sources (such as automotive power or power from a UPS backup) also need to be accounted for. It’s not uncommon for these systems to be populated with CAN bus, DIO, and serial connectors for this reason.

As you can see, rugged edge computer motherboards have significant built-in protections, but they’re still a sensitive piece of technology.

The mechanical design of the chassis is the main defense for the motherboard, and its design is primarily driven by the board size, I/O population, and various thermal solutions responsible for dissipating the heat generated by internal components (see below). Not to mention, the chassis itself must also be designed in a way that can transfer or tolerate kinetic energy including impacts (drops or falling objects) and vibration (in a vehicle).

Thermal Engineering for Edge Computers

One of the main failure points for computers is the fan. Removing this failure point and protecting the system from dust and debris extends system longevity, but the heat it generates must then be ejected in other ways.

A photo of a dirty PC)
Fans that are used to cool a typical computer can introduce dust into the inside of a computer and are one of the most common causes of PC failure.

Cooling for fanless systems must be done passively through the heatsink and chassis of the system, which you can learn more about in more detail in this blog post about fanless pc cooling. But generally speaking, the more heat a system generates, the larger the heatsink required to keep the system operating normally. Because there is a limit on the size of the heatsink that sits directly on the processor, the chassis must be able to dissipate the additional heat in one way or another.

fanless heat transfer process for rugged edge computers

While a surprising amount of heat can be ejected from the CPU this way, processors will still throttle down their performance at higher temperatures (especially in environments that are hot to begin with). This built-in protection keeps the processor from overheating but can cause significant performance and reliability degradation.

We’ll talk more about this later, but it’s worth noting that if a system is pushed to its max constantly and is throttling as a result (as we’ve seen happen in some projects), it generally means that the hardware, as configured, isn’t up to the task. For systems under constant load, it’s far more preferable to be operating at 75-85% capacity, allowing for room to boost only when necessary. It can be easy to over or under spec (both can be costly), which is why testing and working with a hardware specialist are so important.

Components of an Edge Computer

Adding to this growing list of sensitive technology in need of protection (while creating more heat to deal with) are the various components that populate the board; SSD and HD drives, RAM, co-processors (like Movidius VPUs), wireless and cellular cards, and even GPUs. While many of these components have robust rugged versions, they still have their own individual performance traits and temperature ranges that must be considered to ensure proper performance as a whole. In the case of GPUs, which can generate large amounts of heat, OnLogic has created a fanless hybrid solution in our Karbon line. In this fanless hybrid solution, only the GPU is fan cooled which protects the rest of the computer from any dust or debris which may be introduced by the fan.

The Importance of Testing and Verification

While the combination of ruggedized components, design, and thermal engineering help create incredibly tough computers, it’s the testing of these features during the design process that helps inform how they’ll perform out in the real world.

Every manufacturer is responsible for its own testing, which can be done in-house (if testing equipment is available), at a lab (which has specialized testing equipment), or a combination of the two.

rugged edge computers in extreme cold testing

Karbon 300 going through OnLogic’s in-house temperature test chamber, withstanding sub-zero temperatures.

For our own rugged edge computer designs, we run a battery of tests that push the system to its limits, keep it there, and monitor its performance over time. During this testing process, we also populate the system with as much I/O and internal connectors as possible to simulate real-world usage and subject it to conditions that are extreme – usually worse than what the system would typically be exposed to.

Recalling our earlier comment before about throttling, there’s also a nuance between reliability testing (which refers to whether or not the system can remain operational in the conditions it’s being subjected to) and performance testing (which describes how well the system can perform in those conditions). Unfortunately, there’s a bit of disparity that currently exists around this.

As we began testing our Karbon 300 rugged edge computer, for example, we had specific performance benchmarks we wanted to reach. At the design level, we wanted the system to perform to its full potential throughout the extreme temperature ranges without significant throttling, which is not an uncommon occurrence at these end ranges.

During this process, we tested several other systems currently on the market to get an understanding of how they perform comparatively. What we noticed is that there is a significant performance trade-off that occurs as a system reaches the far end of its temperature range.

What’s important to note here is that while these systems can technically operate at these extremes, how well they perform at these ranges is largely left undocumented. But this level of insight is important when you’re counting on a specific level of performance for your application, especially when speccing out systems to deploy.

Finding the Right Fit

With so many factors and data points to consider, it can be tough to find the right solution when speccing out hardware. Especially when the performance you’re expecting doesn’t align with the specifications that are attributed to the system.

Since 2003 we’ve been working with innovators all over the world who integrate reliable computer hardware into their application. We’ve seen what works well and we’ve seen the challenges that hardware integrators have faced when deploying computers in places that are not a good fit to their sensitive technology.

Armed with this information, we also encourage you to talk to your hardware supplier about the testing that’s been done on the systems you’re looking to spec. Has it been tested at all extremes, fully populated, and what are the trade-offs? Ensuring that what is on paper actually matches your application requirements sometimes requires more information than what’s generally provided.

rugged edge computers
We offer a range of rugged edge computers suitable for challenging environments.

By building more flexible options with rugged features, we’ve been able to develop a portfolio of rugged edge computers that fit a wide range of applications and functionality.

Are you looking for a rugged edge computer for your application? Click here to browse our full line of rugged edge PCs or click here to get in touch with a system expert who can help you find the solution that’s right for you.

*This post was originally published on May 14, 2019. It was updated on July 15, 2020.

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