I posted a while back on the unpleasant ride I had in the back of a 777. Held as still as I could, my coffee was spilling from an inch below the rim as it slopped side to side. The slightest chop set it going again. Practically the whole flight was like this.
I had come to the conclusion that the flexing seemed to be out of phase with the correction. The statement above describing remote sensors seems to belie this however.
I don't know, but as a paying guest, it was bad enough, but as someone with a lifetime in aviation, it made me wonder just how far we haven't come in all these years of design 'improvement'.
The 'man made' stresses on that fuselage seemed completely unacceptable.