Patent ID: 11959547
Assignee: ZF CV SYSTEMS GLOBAL GMBH
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F | IPC F

Claim 8:
9. A method for ascertaining an external magnetic interference field by a sensor arrangement (46) for an automated transmission having a shifting device (2) including multiple shift rails (4, 14, 24, 34) arranged axially parallel to one another and being axially displaceable by associated shift actuators (8, 18, 28, 38), wherein the sensor arrangement (46) has multiple displacement sensors (48, 56, 64, 72), each of which comprises a signal transmitter (50, 58, 66, 74) attached to one of the shift rails (4, 14, 24, 34) and a signal receiver (52, 60, 68, 76) fixedly arranged on a housing, wherein the signal transmitters (50, 58, 66, 74) are each in the form of a permanent magnet having magnetic poles, wherein the signal receivers (52, 60, 68, 76) are each in the form of a 3D Hall sensor, and wherein the signal receivers (52, 60, 68, 76) are connected to an electronic transmission control unit (44) via electrical sensor lines (54, 62, 70, 78),
wherein the signal transmitters (50, 58, 66, 74) are arranged having an identical axial alignment of their magnetic poles (N, S), and wherein the signal receivers (52, 60, 68, 76) are arranged in a common plane (80) that is horizontal in an installation position of the signal receivers,
the method comprising the steps of:
detecting sensor signals of each of the signal receivers (52, 60, 68, 76) at a fixed interval (ΔtS);
storing current signal values (xS) of the sensor signals, and
determining a presence of an external magnetic interference field in response to detecting that the signal values (xS) of at least two signal receivers (52, 60, 68, 76) simultaneously have a signal value change at a time when a gear change operation of the transmission has not been triggered.