Method and circuit for detecting a short circuit of the sine or cosine receiver coil of a resolver

Abstract

A method for detecting a short circuit to ground or to the operating voltage of a signal line (11, 12) of a resolver (16) has the following steps: - measuring the potential of the signal lines (13a, 13b; 14a, 14b) of the receiver coil (18) with respect to ground at two sampling times (R and F) provided symmetrically at the middle of the excitation period; - calculating an offset value for a signalline pair (13a, 13b; 14a, 14b) by calculating the average value of the four measured values (UHR, ULR, UHF and ULF) for the associated receiver coil (17, 18); and - identifying a short circuit and the potential to which the short-circuited line is connected in that the offset value is compared to threshold values.

Description

technical field [0001] The invention relates to a method for detecting a short circuit of a resolver signal line of a sine receiver coil or a cosine receiver coil to ground or to an operating voltage, and to a circuit for implementing the method. Background technique [0002] A resolver is used to know the angular position of a rotating object, such as the drive shaft of a motor. Various resolver types exist in the prior art. In principle, a changing magnetic field is generated by means of at least one coil and detected by means of at least one other coil, wherein the strength of the coupling between the coils changes depending on the position or angular position to be measured. In a “variable reluctance resolver” (VR resolver), for example, only one excitation coil is used and there are two measuring coils which generate position-dependent signals. German patent application DE 10 2011 078 583 A1 discloses, for example, an evaluation of resolver sensor signals in a vehicle...

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