BY NAIRAH THAHA
There are two things required to make an indoor AR location app:
- Beacon Technology:
This method entails placing Bluetooth Low Energy beacons (BLE) around the areas you wish to have mapped out. These beacons are small in size and easy to hide. Whenever the user walks into the range of the beacon, it sends out a signal to the AR app via Bluetooth which alerts the software to the position of the user.
The advantage is that the accuracy of the navigation is high since the app is being fed direct information. The cost of creating such a service goes up when you want to cover larger spaces indoors as you will need a lot of sensors.
- AR Technology:
If you have used an Augmented Reality app that makes use of ARKit/ARCore frameworks, you would have noticed that once you place 3D content on to a surface, you are able to walk away from it and see that its location persists in the real world. This is done by making use of motion tracking technology using the sensors mentioned above so that it is able to establish how far you have walked and in which direction.
Harnessing this technology, we are able to make indoor navigation apps in Augmented Reality using only sensors. What must be considered, though, is that because of the high frame rate of the sensors small measurement errors can accumulate over time to cause a significant error referred to as “sensor drift.”
The other thing to keep in mind is that the phone needs to be aware of the initial starting point and orientation in order to establish its position. This can be done in many ways, but most commonly users will be asked to scan a predefined image target which lets the app know the initial position and rotation of the phone.
BY NAIRAH THAHA
What is Indoor AR Navigation?
Indoor AR Navigation is used in applications to allow users to easily select where they want to go to in an indoor space – such as in a mall and in an office – and be able to see the path clearly marked out from their current to their desired location. Augmented Reality includes the user’s surroundings and allows the navigation to be displayed in context with the environment.
How does Indoor AR Navigation work?
Up-to-date mobile phones are capable of running the latest Augmented Reality frameworks; ARCore and ARKit which are specifically for Android and iOS. These mobile phones are AR compatible because they have various sensors that allow for motion tracking. The accelerometer in the phone measures the change of velocity (acceleration) of the phone to help track the user’s movement. The gyroscope measures the orientation and angular velocity of the phone and its camera. The camera itself supplies live feed information to the AR software to be processed in order to produce spatial maps of the surroundings.
For accurate tracking of the user’s orientation, modern mobile phones have a magnetometer. This informs the application of the phone’s orientation in relation to the earth’s magnetic field. This helps determine which way the phone is facing so that the application can provide appropriate directions. Mobile phones also have built-in Global Positioning System (GPS) which provides geolocation services.
Why is Indoor Navigation not as straightforward as Outdoor Navigation?
GPS does not work indoors. This is because the satellite signals are too weak to penetrate walls and roofs. This means that indoor navigation needs to rely on the use of mobile sensors and other external sensors in order to receive accurate location services.