I am trying to find a position estimate of my Arduino Nano 33 BLE Rev 2. I have done some research before this, but I haven't found a concrete answer on which algorithm is the best and some people just say it is not possible. I am not able to have it be tethered or transfer data to it over Bluetooth / Wifi. It is working in a 3m by 10m area, and, optimally, it would be accurate within < 5 cm for 10 - 20 seconds. Is there any easy way to do this and if not what is a better way to do it?
If you are asking about using consumer grade IMUs to make useful position estimates, that is not possible.
This question has been asked hundreds, if not thousands of times on the Arduino forum. The best answer is that if it were possible, cheap modules would already be available for that purpose.
So if IMUs are not able to be used what would be another way to do this?
Ultra Wide Band (UWB) positioning is possible over an area that size, with an accuracy of about +/- 10 cm. You need 3-4 anchors on the corners, and a roving tag.
Outdoors, RTK GPS can give you mm accuracy. Sparkfun sells setups for around USD 1000.
Overhead cameras combined with image processing is the cheapest option.
If you take a few moments to describe the actual project in a bit more detail, you will probably get better answers.
For my project I am trying to have a car drive itself from a start point, through two cans, and get as close to an end point as possible. I am not able to have anything outside the car.
Wheel encoders are popular, but wheels slip, so most people combine them with cameras or distance sensors to detect obstacles and/or maintain spacing from walls.
Check out the Micromouse contest.
If I had to use accelerometers which one would you recommend?
You can buy commercial IMUs that do what you want, with price depending on position/orientation accuracy and stability, in the general range of USD 10K to 100K. They are used primarily in aircraft.
This is not a simple problem, so consider it to be a learning opportunity.
have you considered triangulating on IR beacons or is that too constrained?
Hi, @foundtracker24
You might be using the wrong hardware.
Ultra-Wideband is an incredible technology capable of providing* precision distance measurements,* and it is now at the point where you can start using it in your maker projects! In this video, we will be taking a look at how it works, what you can do with it, and how to use the AI Thinker BU03 boards to your next project (with some demo code examples of course).
Tom.... 
