Verfahren zur sensorlosen Schritterkennung bei Schrittmotoren

摘要

A process is disclosed for recognising the step of stepping motors by analysing the current that flows through the motor, without using any sensors. In order to overcome the problems caused by the use of a shunt resistance, the resulting current measurement errors and toggling, and to ensure a as disturbance-free and reliable operation as possible in all operation states of both unipolar and bipolar stepping motors, the disclosed process has the following steps: a defined current (T2) is transmitted to a motor winding (B) after a reversal (T1) of the current flow direction in a first motor winding (A); a motor winding connection (B) is switched with a high ohmic value (T3); the response signal (S) at the motor winding connection (B) switched with a high ohmic value is sensed; the length (T3-T4) of the response signal is evaluated. Alternatively, triggering is provoked by an external triggering signal, independently of the reversal of the current flow direction.