How to obtain speeds in NED coordinate system from the speed and course obtained with matlabMobile from the position sensor of an Android smartphone?

Thanks in advance.

I need to know the NED speeds from the sensors of a smartphone to implement them in a Kalman Filter. GPS in addition to LLA, returns a single value for speed, heading, and horizontal accuracy.

Sincerely

Answer 1

[Tushar]

Hi Manuel,

I understand that you need the sensor data like GPS, speed, etc. in the North-East-Down (NED) coordinate system, using MATLAB mobile. Refer to the steps listed below:

• Check MATLAB Support Package for Android Sensors: This enables you to collect sensor data (acceleration, angular velocity, orientation, magnetic field, and GPS sensors) from your mobile Android device.
• Try the 'Position and Motion' functions-

Sensor Data Collection

• Processing the data received: The data received in 'geodic' coordinates can be transformed to 'NED' coordinates using lla2ned function.

% Data in geodic coordinates
lla0 = [46.017 7.750 1673]; lla = [45.976 7.658 4531];
% Transformed into NED coordinates
xyzNED = lla2ned(lla,lla0,"flat")

xyzNED = 1×3

1.0e+03 * -4.5572 -7.1244 -2.8580

I hope the above steps will help you collect the data in the required format. For more info, refer to the articles below:

1. Logging Accelerometer Data - An example showing how to manipulate and visualize 'Accelerometer Data'.
2. Process Logged Sensor Data - An example showing how to plot 'Orientation Data' acquired.
3. Fitness Trackers using MATLAB mobile - A blog showcasing the workflow of how a group of high school students created a Fitness Tracker app.

[Manuel Infante Francés]

Thank you Thusar