Patent ID: 11901781
Assignee: ROBERT BOSCH GMBH
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A brushless electrical machine, comprising:
a housing;
at least one rotor, which is positioned on a shaft for being rotationally moved in the housing by a motor;
a stator attached to the housing; and
a rotor position detection device, the rotor being assigned the rotor position detection device, the rotor position detection device being configured to operate contactlessly and includes a multipole magnetic ring positioned on the shaft in a rotatably fixed manner, and at least one sensor, which is sensitive to magnetic fields and is attached to the housing radially with respect to an outer circumference of the magnetic ring; and
a control unit
wherein:
a number (x) of pole pairs of the rotor and a number (y) of pole pairs of the magnetic ring are coprime; and
the control unit is configured to, upon the motor being switched on, determining in which of a plurality of predefined angular segments an angular position of the rotor is located;
each of the plurality of predefined angular segments includes a respective range of degrees, with a combination of the respective ranges totaling 360°;
the determining is performed by executing a program that predefines:
an algorithmic sequence of steps of (a) respective outputs of current corresponding to respective target movements of the rotor in respective predefined directions by a respective number of degrees and (b) respective subsequent determinations of whether the rotor moved in the respective predefined directions to which the respective outputs correspond; and
different combinations of, during the sequence of steps, determinations of the rotor, in response to the respective outputs of current, (a) moving in the respective predefined directions, (b) moving opposite to the respective predefined directions, and (c) not moving in response to the respective outputs of current as indicating the rotor to be positioned in a respective one of the plurality of predefined angular segments, the predefined different combinations including, for each of the predefined angular segments, at least one respective combination that, when determined by the control unit to occur, results in a respective determination by the control unit of the rotor being positioned in the respective predefined angular segment.