i'm using matlab mobile to collect imu data in vehicle from my iphone i needed to know how to adjust the axis ?

i'm using matlab mobile to collect imu data in vehicle from my iphone i needed to know how to adjust the axis so that the front of the car is the x-axis and y-axis is the pointing to right door and z is down (given that the front of the mobile is pointing to front of the car and the screen is pointing to the celling ).and how to convert from collected orientation azimuth,roll,pitch to yaw,roll, pitch ?

Answer 1

[Vilém Frynta]

When you go into "Sensors" in Matlab Mobile, you can see variables measured by your mobile sensors in real-time. You can simply move your mobile phone in some of those directions: front of the car is the x-axis and y-axis is the pointing to right door and z is down. Moving your phone in any of the directions will detect the acceleration and reveals a relevant axis. Then, when you are familiar with your phones axis, you can adjust mobile phone in your car to match your requirements.

Most likely though, the axis on your phone will be as in this picture:

Source: Sensor Data Collection with MATLAB Mobile - MATLAB & Simulink (mathworks.com), that might be a useful link to check.

[ahmed mohammed]

ok thanks , how to convert from collected orientation azimuth,roll,pitch to yaw,roll, pitch ?

[Vilém Frynta]

roll = roll;

pitch = pitch;

azimuth is an angle of your direction in relation to northern pole (i think). so, i think that yaw is the difference in the azimuth. for example, if your azimuth is 150°, and then you turn and it's 50°, yaw will be 100°

see: