Getting tilt angle (axial tilt) from roll, pitch and yaw

Other Hardware Sensors
1

Hi, everyone.
I am using arduino UNO with MPU6050 sensor and ADNS-9800 sensor. Using the library, i managed to get the yaw, pitch and roll. Now I want to know how much higher my mobile robot is moving on a slope. I plan to do so by using the angle from plane tilt and with linear distance from ADNS-9800.

There are a lot of rotation matrix and also tilt-compensation algorithm but honestly, I am not sure how to calculate the tilt angle from the data I have. Any suggestion or links would be much appreciated. Thanks.

2

http://playground.arduino.cc/Main/MPU-6050

Maybe you should read this:

This diagram shows calculations of tilt angles from the measured acceleration vectors. Diagram comes from this site. ? and ? are defined as tilt with respect to the X- and Y-axes respectively, while ? is defined with as tilt of the Z-axis with respect to gravity. Please note that while ? and ? are the same as pitch and roll, ? is NOT the same as Yaw. Yaw cannot be computed from the accelerometer.