The marvelmind robotics indoor position system provides a very affordable and highly accurate (2cm at up to 45hz) method for indoor localisation where GPS is not an option (such as indoors).  This system consists of fixed beacons and mobile beacons (on the moving object you want to track) , and each system communicate via a mesh network on the ISM band.  The team at marvelmind robotics have developed this kit to be approximately 10x cheaper than its competition while being about 5x more precise.  This is an ideal solution for indoor drone labs, indoor assistant robots, tracking people in your facility, or even virtual reality applications.  The only limitation of this system is that one beacon needs to have an unobstructed view of another for it to calculate its position, however, given that you can mount the beacons on ceilings/walls this can be easily overcome.

This starter kit includes everything you need to have a fully functional indoor tracking system.  This kit includes 1x mobile beacon, 4x stationary beacons, 1x router.  It should also be noted that a beacon can be set to be a stationary or mobile beacon via software.

You can add extra beacons to increase the coverage area (Using static beacons) or track more objects (using mobile IMU beacons)

Key features

• High-precision (+-2cm) indoor navigation system for autonomous robots and systems (“indoor GPS”)
• Supports arducopter firmware to send simulated GPS information to your drone for indoor flight
• Indoor tracking and positioning of objects and humans equipped with beacons
• Coverage radius of a single beacon is up to 50 meters
• Supports USB, UART, SPI and I2C interfaces on mobile beacon
• Radio interface: 433MHz & 10mW – up to 100m in office environment
• Up to 1300h (>100 days with 12h/day & 1Hz location update rate) in active mode when powered from battery. Up 2y in deep sleep mode

Beacons

Beacons are interchangeable between stationary, or mobile beacons (via the software).  Stationary beacons function similar to how GPS works, allowing a mobile beacon to triangulate its position using ultrasonic time of flight signals.  Each beacon is powered via a built in battery, but can accept an external power source.  Each beacon includes a bunch of IO (UART, SPI, i2C, USB) to allow for easy communication with your robot platform.

Router

The router is a central controller for the positioning system and is able to calculate the position of each mobile beacon at up to 45 times per second depending on the data rate you have set.  The range of this device is between 100-400m depending on what data rate you set.  The marvelmind router communicates with the beacons via ISM band using a proprietary protocol.