Hi there, i'm working on altitude hold algorith on a quadcopter, many quadcopter factories use accelerometer and barometer fusion to estimate a good altitude. but i d'ont understand how they fusion the z accelerometer with the barometer ??. i did some experience , i integrate twice the z acceleration but the accelerometer is verry verry noisy and it's very sensitive from vibration and even the quadcopter doesn't move the noise will drift the velocity over the time. My question if some geniouse can explaine me how does it work ? i would like to program the altitude hold on my quadcopter. also i know the kalman filter but i don't know how do i fusion the z acceleration with the baromter. here it is a video that shows someone fusion the z velocity with the baromoter.
if someone can explaine the secret of this technic.