Rotation rate measurement

摘要

The method involves detecting signal sources (2-9) arranged on the circumference of a rotating system (1) with a sensor (10). The total number of signal sources is M. At the same time, a corresponding time reference value AN is recorded. Each signal source (2-9) detected by the sensor (10) is counted and is stored pair-wise with the corresponding time reference value as a signal sum N in a memory (11). The time reference value stored precisely one rotation earlier is read out from the memory (11). The difference between the time reference signals for the current source and the earlier source is calculated and from the difference the rotation time for one rotation of the system is calculated. The reciprocal value of the rotation time is formed. This value represents the rotation rate of the rotating system (1). The same calculation for the rotation rate for a full rotation of the system (1) is carried out for the next signal source in the direction of rotation.