Sensor with interface for functional safety

Patent metadata

Field	Value
Publication number	US-9863786-B2
Application number	US-201414316208-A
Country	US
Kind code	B2
Filing date	Jun 26, 2014
Priority date	Jul 17, 2013
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

A sensor interface operates to communicate a sensed quantity along one or more processing pathways and in different data representations. The signal representations can be swapped along one or more locations of the signal processing branches. These branches are independent from one another and combined at an interface component for transmission along a single path or node for a control unit.

First claim

What is claimed is:

1. A sensor system comprising:
a sensor stage comprising at least one sensor element of a sensor configured to provide a first signal component in a first data representation and a second signal component in a second data representation to generate a sensor signal of a sensed quantity in different representations;
a signal processing stage, coupled to the sensor stage, comprising a first signal processing branch configured to operate upon the first signal component of the first sensor element and the second signal component of the second sensor element;
an interface configured to provide the sensor signal as a function of the first signal component and the second signal component to a node; and
a control unit component configured to detect an error of the sensor stage, the signal processing stage or the interface based on a detection of the first data representation or the second data representation not corresponding to a separation in a range or a separation in a time domain.

2. The sensor system of claim 1 , wherein the first signal component and the second signal component comprise a proportional relationship to one another and differ according to different representations of the sensed quantity that comprise different trigonometric representations or different inverse representations of the sensed quantity.

3. The sensor system of claim 1 , further comprising:
a switching component configured to alternate the first signal component received for processing at a first sensing branch with the second signal component received for processing at a second sensing branch, or alternate a polarity of the first signal component at the first sensing branch.

4. The sensor system of claim 3 , further comprising:
a sequence controller configured to control the switching component based on a set of monitoring signals configured to determine an operational status of a pull up transistor and a pull down transistor.

5. The sensor system of claim 1 , further comprising:
a synchronizing component configured to determine timeframes associated with the first signal component and the second signal component, wherein the first data representation and the second data representation differ with respect to one another based on different time multiplexing.

6. The sensor system of claim 5 , wherein the synchronizing component is further configured to generate a comparison of a modulated signal period with an independent oscillator and synchronize the at least one sensor element based on the comparison.

7. The sensor system of claim 1 , further comprising:
a high state component configured to receive a first output from the first signal processing path of a first sensor element and control a pull up transistor; and
a low state component configured to receive a second output from a second signal processing path coupled to a second sensor element and control a pull down transistor, wherein a duration of an operational status of the pull up transistor and of the pull down transistor is based on a range of separation along a signal range of the first signal component and the second signal component, or a time of separation in a time domain of the first signal component and the second signal component.

8. The sensor system of claim 7 , further comprising:
a low side controller configured to lock the low state component based on a determination of whether the high state component is actively operating the pull up transistor; and
a high side controller configured to lock the high state component based on a determination of whether the low state component is actively operating the pull down transistor.

9. The sensor system of claim 1 , further comprising:
a switching component configured to alternate the first signal component in the first data representation of the sensed quantity from the first sensor element with the second signal component in the second data representation of a same sensed quantity within the first signal processing branch and a second signal processing branch, wherein the first data representation and the second data representation differ based on a separation of a range of a duty cycle.

10. A sensor interface module for interfacing one or more sensor signals between at least one sensor and an engine control unit comprising:
a first sensor element configured to communicate a measured quantity in a first data representation;
a second sensor element configured to communicate the measured quantity in a second data representation;
a switching component configured to swap between communicating the first data representation of the measured quantity and the second data representation of the measured quantity; and
an interface component configured to generate an output signal to a node as a function of the first data representation and the second data representation;
wherein the engine control unit is configured to receive the output signal at the node and interpret the output signal based on the first data representation and the second data representation differing from one another as a function of a separation in at least one of a duty cycle range, a time domain range, or a time multiplexing.

11. The sensor interface module of claim 10 , wherein the first data representation comprises at least one of a first addend of a sum and the second data representation comprises a second addend of the sum, a cosine representation and a sine representation, or a first inverse representation and a second inverse representation, respectively.

12. The sensor interface module of claim 10 , further comprising:
a synchronizing component configured to generate a comparison of a modulated signal period of the output signal with an independent oscillator, wherein the first data representation and the second data representation differ based on a time of separation in a time domain.

13. The sensor interface module of claim 10 , wherein the first sensor element comprises a first sensor bridge configured to generate the first data representation of the measured quantity, and the second sensor element comprises a second sensor bridge configured to generate the second data representation to comprise a proportional relationship to one another and differ according to different representations of the measured quantity that comprise different trigonometric representations or different inverse representations of the measured quantity.

14. The sensor interface module of claim 10 , wherein the switching component is further configured to swap a first signal component in the first data representation and a second signal component in the second data representation between and before a first signal processing path and a second signal processing path, after the first signal processing path and the second signal processing path, or within the interface component.

15. The sensor interface module of claim 10 , wherein the switching component is further configured to swap different polarities of the first sensor element and the second sensor element to communicate the first data representation and the second data representation of the measured quantity based on an asymmetrical sequence for identification of at least two time periods corresponding to the polarities, based on different durations, or based on a marker inserted into a point in a swapping sequence for swapping the polarities.

16. A method for a sensor system comprising:
providing, via a first output of a first sensing element of a sensor, a first data representation of a sensed quantity by generating the first data representation as a sine signal, a first inver

Assignees

• Infineon Technologies Ag

Inventors

• Reidl Christian
• Granig Wolfgang
• Witschnig Harald
• Hammerschmidt Dirk

Classifications

• G01D1/16 Primary

  giving a value which is a function of two or more values, e.g. product or ratio · CPC title

• G01D3/024

  for range change; Arrangements for substituting one sensing member by another · CPC title

• G01D21/00

  Measuring or testing not otherwise provided for · CPC title