Method and device for digitally determining a number proportional to the rotational speed of a body

摘要

The subject-matter of the invention is a method for determining a number which is proportional to the rotational speed of a body. An angulometer (angle transmitter) is used to carry out a time measurement by counting periods of a reference oscillation. In the event of changes in the angular position of the body, the value of the angular position is updated and stored. The time value present at the instant of the change is stored. The stored angular position value is read out. The stored time value is subtracted in time intervals given by a constant interrupt interval from the angular position value read out in the respective preceding interrupt interval. This is also performed with the time values. The difference in the angular position values is divided by the difference in the time values and multiplied by a constant. The number of the periods of the local reference oscillation which occur within a global time interval generated by a central time base is recorded. A correction factor for the rotational speed measurement is determined from the ratio of this recorded number to a predetermined number. <IMAGE>