I am using MEMS 3 axis accelerometer to measure the acceleration along all the 3 axis when the accelerometer is mounted inside the vehicle tyre. The testing was carried out for different speeds.
When the accelerometer mounted wheel is in operation(runned assuming the wheel is balanced),the graphs plotted extracting the data from the accelerometer at different speed are as shown below. ]2]
Here the issue is with acceleration along the z axis. As the speed is increased the z graph is lifted upwards and when it reaches 2g the graph is clipped off. As per prediction the acceleration along both x and z axis has to remain same with some phase shift (this is because when wheel is rotating there will be variations only along 2 axis, in this case it is x and z. the variation along y axis shows the vibration along lateral axis or y axis only). Can anyone help me understand why is this happening? Kindly suggest if my prediction is wrong too.