Human Presence Detection and You

Mobile phones and tablets are getting more powerful, but if you’re serious about doing work (remotely), the dedicated work laptop still reigns supreme. In this new paradigm of working anywhere, privacy and productivity have become increasingly important. To help with both, human presence detection technologies have come to the forefront recently. In a prior post, I discussed a number of different sensors used to detect human presence for a variety of different applications. However, now I want to focus our presence discussion on the more specific use case of mobile computing: what it can be used for and the more prominent technologies used.

Instant Productivity and Security

Imagine you find a nice nook in the corner of the coffee shop where the aroma of the beans hits just right and it’s cozier than the rest. As you approach your nook of the modern day oasis, the positive feelings inspire you with a wonderfully creative thought. You sit down to type it up, but while logging onto the computer, your brain gets distracted by the login screen and your brilliant thought fades away. This unfortunate situation can be avoided with human presence detection recognizing you and logging you into your computer immediately so you can open up your text editor and jot down your idea. And that’s exactly what human presence detection can do.

Now, I’m aware I’m being a bit facetious with my example here, but the point stands. Logging you in the moment you open up your laptop helps you get to what you need to get to faster. In the same way that an individual hotkey isn’t a huge deal, but over time, you notice you can work more efficiently. This is like having a hotkey for logging in.

Security is arguably more important than productivity, because how could you do work if your property or data was compromised? To continue with the coffee house example, when you hear your name called and step away from your laptop to pick up your coffee, human presence detection determines you’re not there and can lock your PC so keep your data secure and unlock the moment your return. Like nothing ever happened.

Say you’re working on a novel (or I don’t know… a blog article about human presence detection) and someone walks up behind your laptop to read over your shoulder. Human presence detection sensors can detect that someone else is around and alert you or even blur the screen to avoid unwanted eyes from stealing your ideas.

These sensors can also be used to keep track of where your face is looking, keeping tabs on your eye health (by letting you know when you’ve looked at the computer for too long). Or they can be used for gesture control to give you some basic slide control from afar. These are just some of the capabilities that are possible with some creative thinking and software.

Sensing Presence

Three prominent technologies for human presence detection are listed and described below. One commonality between these sensors is that they all get their information by something hitting their respective receivers.

Time of Flight (ToF) Sensors:

These sensors emit a signal that reflects off a surface and measures the time it takes to return to the sensor. This can be done with different types of signals including lasers (LIDAR), infrared (IR), and ultrasound. Time-of-flight sensors use an array of sensing pixels to determine relative distances from the object, creating a range map. Time of flight sensors are the most prevalent due to their low cost and smaller size.

Low power camera:

Instead of emitting their own signal, low power cameras capture photons (from light) on a grid of sensors that determine color and brightness. The source of photons is whatever source of light already present in the space, whether its an LED, fluorescent, or natural sunlight. With a camera you get the advantage of more readily appreciable information to a human, but are dependent on lighting conditions.

Ultra-wideband (UWB) or mmWave:

Ultra-wideband operates similarly to radar, where radar pulses are sent and their reflections measured. The main difference here is that UWB signals are very low energy, designed specifically for short range. Unlike the camera, it can operate in any light condition. UWB sensors have high sensitivity as well, even being able to detect heart rate. But these features come at a higher price (literally) than the other sensors.

Each of the prominent technologies has distinct benefits and drawbacks, and determining which is best for your human presence detection application requires a strong understanding of sensors. Regardless of which technology you chose, CEVA’s strong background in sensors (especially with a dedicated sensor hub) can simplify your productivity and security requirements, letting you focus instead on (your creative vision/delicious coffee or) the best user experience. Contact us to learn more about our HPD capabilities.

Published on EEWorldOnline and SensoreTips.

#HPD #human presence detection #Low power camera #mmWave #Sensing Presence #time of flight sensors #ToF #uwb