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Methods and apparatus for detecting a sensor angle error in a system in which a measured quantity is determined on the basis of a phase of a signal. A signal derived from the measurement of multiple sensors is ascribed to a vector in a two-dimensional space, and a norm is calculated characterizing t

Methods and apparatus for detecting a sensor angle error in a system in which a measured quantity is determined on the basis of a phase of a signal. A signal derived from the measurement of multiple sensors is ascribed to a vector in a two-dimensional space, and a norm is calculated characterizing that vector. A value is calculated characterizing variation of that norm over a specified period of time and that value is compared with a threshold in order to identify a sensor fault.

대표청구항 ▼

What is claimed is: 1. A method for detecting a sensor angle error in a system employing a rectangular-to-polar coordinate conversion, the method comprising: a. ascribing multiple sensor measurements to a vector in a two-dimensional space; b. calculating a norm characterizing the vector; c. determi

What is claimed is: 1. A method for detecting a sensor angle error in a system employing a rectangular-to-polar coordinate conversion, the method comprising: a. ascribing multiple sensor measurements to a vector in a two-dimensional space; b. calculating a norm characterizing the vector; c. determining a single scalar value characterizing variation of the norm over a specified period of time, the single scalar value amenable to scalar comparison; and d. comparing the single scalar value characterizing variation of the norm to a specified threshold value; and e. enabling fault-handling procedures in case of variation of the norm exceeding the specified threshold. 2. A method in accordance with claim 1, wherein the step of determining a single scalar value characterizing variations of the norm includes: i. determining a first value characterizing a time-averaged minimum of the norm; ii. determining a second value characterizing a time-averaged maximum of the norm; and iii. calculating the single scalar value characterizing variation of the norm as a function of the maximum and minimum of the norm. 3. A method in accordance with claim 2, wherein the function of the maximum and the minimum of the norm is a ratio of the maximum to the minimum. 4. In a sensor system of the type employing a rectangular-to-polar coordinate conversion, an improvement comprising; a. a plurality of sensors for generating analog sensor signals together defining a vector in a two-dimensional space; b circuitry for combining the analog sensor signals to create a plurality of demodulated signals of known phase relationship; c. a norm processor for combining the plurality of demodulated signals to derive a single scalar norm characterizing the vector; and d. a comparator for comparing a function of the single, scalar norm to a specified threshold, wherein the function characterizes behavior of the norm over a specified period of time. 5. The improvement of claim 4, wherein the function is a ratio of a maximum to a minimum of the norm over the course of a cycle.