In the previous post in this series on designing the perfect human-machine interface (HMI), we looked at the nitty-gritty of machine design: its electronics. Today, in our final post of this series, we’re going to assess the operating environment and its implications for HMI design. Some questions that you might need to evaluate include the following.
Does it need to be able to weather outdoor conditions?
If the machine is going to be exposed to the elements, including rain, sunlight, and temperature fluctuations, it can have profound obligations for how the machine is housed and how its delicate components, like its HMI, are protected. This kind of setting will necessitate that the machine be fully sealed, likely IP-rated, and will require an enclosure that can withstand the conditions.
Will it be exposed to extreme conditions?
Whether outside or indoors, if the machine is expected to perform under particularly difficult or unusual conditions – like exposure to temperature extremes, radiation, cleanroom environments, and so on – it needs to be built with that scenario in mind. Ultimately, the machine is only going to be able to endure the conditions that its weakest component can handle.
Will sanitation or hygiene be a consideration?
For some industries, it’s critical to ensure the ability to clean and sanitize the machines, particularly where the human operators might touch it. This includes both food production and medical environments. Different options can profoundly affect this aspect of the machine. For example, porous materials like rubber are difficult to disinfect and make good homes for microbes. By contrast, a machine that’s easy to disinfect even with strong cleaning agents at a wipe will be preferable in this kind of environment.
Does the operating environment affect how the user will interact with the machine?
For example, if the machine is going to be placed in environments where human users are wearing personal protective gear, like heavy work gloves, that will make some interface options less helpful. For example, some types of touchscreens won’t be able to detect inputs from gloves. In those cases, a physical switch, like a membrane switch, would work better. It’s not just touch, either; if users have to wear goggles or other protective gear around their face, such protective gear can limit visibility, which may mean the HMI needs to be even brighter, larger, or somehow more visible than it would otherwise be.
Does the operating environment introduce risk to the human user or the machine?
This question has two dimensions – safety to both operator and to the machine itself. Machine design should help to protect both users and the machine itself from breakdown or other harm. If operating in a high-risk environment, designers need to consider what build options will protect both the machine and its users. They may need plastic enclosures rather than metal, for example, to prevent static charge buildup. Or they may need to use materials that are fire resistant or retardant. IP-rated enclosures may be necessary to seal the machine from its external environment. And so on.
How do you understand the design implications of your intended application environment? For help understanding your options, please download our “Design Guide To Your Perfect User-Interface.” To start this series of articles from the beginning, read the first entry, “What’s Needed to Design a Successful Human-Machine Interface.”
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