Hi, I wonder if there is anyone who can help me with a problem i have. I have a device that includes a simple 3d accelerometer. The device is a handheld device and my challenge is to figure out the path that the device moves in space relative to its starting position. I would like to plot the path and velocity with time. The challenge is that the device can swivel over time which means that the gravity vector changes and so it complicates the requirement to remove the gravity vector so as to figure out the true acceleration. Additionally, the accelerometer is really not made for violent swings and as such it can clip the output based on excessive movement. The type of movement that takes place is a repetitive movement and so the general path is known and as such i believe that a model of the gravity vector can be created. Someone has experimented with my data and used Kalman filters and cubic splines to try and figure out the information. The path information and velocity does not have to be 100% accurate. I just need a good general trend of how the object moves and the timing. I am not a physicist and my job would be to find an algorithm and then write the software in he embedded hardware. Time is of the essence and if there is someone who could help me figure this out, I would appreciate it.