Accelerometer & gyro accuracy in different mobile device
I want to implement an indoor localisation system using the sensors of a mobile device (accelerometer, compass, gyro) . This problem was already discussed here on several places such as - here and here
The first step is to decide which platform is the best one to implement such a system. The main possibilities are Samsung's Galaxy/ Galaxy tab, or the iphone/ ipad. The most important criteria is the accuracy of the sensors data. However, This comparison is very complicated, as the accuracy is dependent not only on the device itself but also on the software layers above it.
Is there any research available on the subject? Is there a difference between the sensors of smartphones and those of tablets?
Any links to websites or articles would be most helpful
Thanks in advance!
Ariel
Answer
I've developped the very same thing for Android tablets. When it comes to accuracy of the sensors, there are some huge differences between one and another. Recently released tablets tend to have better equipment.
Better in their accuracy, but also as there is an effort to provide sensors from the same constructor for given devices.
Let me explain. I've worked with Galaxy Tabs 7.0 and 10.1. GT7's sensors are provided by various constructors, which ends up in disparities related to polling frequencies. If you have an accelerometer from X and a gyroscope from Y, both being used at their largest frequency (which you do want for better precision), those frequencies won't match. One might be around 10 ms, the other around 15. And that's pretty annoying for calculations. For the GT10, all of the sensors are build by InvenSense on the tablet I used. InvenSense creates sensors and software solutions for inertial navigation (I recommend you to check their website and some of their papers). Not only their accuracy is great, but all of the sensors will work together, and especially when it comes to frequencies.
TL;DR - Prefer using the latest equipment (and probably the most expensive) for better accuracy and luckily adequation between sensors.
Developing an INS with such bad sensors is a tricky thing I can tell, but you can make it work.