Method for measuring vibrations of a vibration machine

A method for measuring vibrations of a vibrating machine, in particular a vibrating screen or a vibrating conveyor, during operation, in which the vibrating machine vibrates at an excitation frequency predetermined by a vibrating drive, wherein a vibration sensor detects a plurality of vibration components of vibrations of the vibrating machine in three spatial directions of a Cartesian sensor coordinate system, and wherein the plurality of vibration components form a vibration vector, the method comprising the steps of:

• determining a gravitational vector which describes a gravitational direction, the gravitational vector being determined as a time average of the vibrations of the vibrating machine detected by the vibration sensor, signals of the vibrations being rounded to an integer number of periods of the excitation frequency;
• determining a machine vector which describes a preferred direction of an imposed vibration of the vibrating machine, the vibrations being converted into Fourier space by a Fast Fourier transform in order to determine the machine vector, and wherein amplitudes of the vibrations of an excitation frequency specified by the vibrating machine determined forming an amplitude vector which points in the preferred direction;
• forming a three-dimensional Cartesian measurement coordinate system which is aligned on a basis of the gravitational direction and the preferred direction, wherein a first axis of the measurement coordinate system extends parallel or antiparallel to the gravitational vector and a second axis of the measurement coordinate system extends along a portion of the machine vector which is orthogonal to the first axis, or a first axis of the measurement coordinate system extends parallel or antiparallel to the machine vector and the second axis of the measurement coordinate system extends along the portion of the gravitational vector which is orthogonal to the first axis;
• and
• mapping the vibration vector from the Cartesian sensor coordinate system into the measurement coordinate system.