Sensor device and electric power steering apparatus using same

Patent metadata

Field	Value
Publication number	US-2016339945-A1
Application number	US-201615158283-A
Country	US
Kind code	A1
Filing date	May 18, 2016
Priority date	May 20, 2015
Publication date	Nov 24, 2016
Grant date	—

Abstract

A sensor device including a first output circuit generating and outputting a first output signal that is generated as a signal sequence from a first main signal based on a detection value of a first main sensor element to a first sub signal based on a detection value of a first sub sensor element, a second output circuit generating and outputting a second output signal that is generated as a signal sequence from a second main signal based on a detection value of a second main sensor element to a second sub signal based on a detection value of a second sub sensor element, and an abnormality determiner determining abnormality of the device based on the first output signal and the second output signal.

First claim

What is claimed is:

1 . A sensor device comprising:
a first sensor part including:
a first main sensor element and a first sub sensor element respectively detecting a physical quantity of a detection object; and
a first output circuit that generates and transmits a first output signal including an ordered sequence of signals in part from a first main signal to a first sub signal, the first main signal generated based on a detection value of the first main sensor element, and the first sub signal generated on a detection value of the first sub sensor element;
a second sensor part including:
a second main sensor element and a second sub sensor element respectively detecting the physical quantity of the detection object; and
a second output circuit that generates and transmits a second output signal including an ordered sequence of signals in part from a second main signal to a second sub signal, the second main signal generated based on a detection value of the second main sensor element, and the second sub signal generated based on a detection value of the second sub sensor element; and
a controller including:
a signal obtainer obtaining the first output signal and the second output signal; and
an abnormality determiner determining an abnormality based on the first output signal and the second output signal, wherein
one of two sets of signals, including the first main signal and the second sub signal, or the first sub signal and the second main signal, are direct signals that are configured to increase as the detection value increases, and remainder of the two sets of signals are inverse signals that are configured to decrease as the detection value increases.

2 . The sensor device of claim 1 further comprising:
a first communication line connecting the first sensor part and the controller for transmission of the first output signal; and
a second communication line connecting the second sensor part and the controller for transmission of the second output signal, wherein
the abnormality determiner detects a short-circuit between the first communication line and the second communication line based on (i) a comparison between the first main signal and the second main signal and (ii) a comparison between the first sub signal and the second sub signal.

3 . The sensor device of claim 1 , wherein the abnormality determiner determines abnormality of data in the first output signal based on a comparison between the first main signal and the first sub signal, and
the abnormality determiner determines abnormality of data in the second output signal based on a comparison between the second main signal and the second sub signal.

4 . The sensor device of claim 1 , wherein
the abnormality determiner identifies an abnormal sensor element having abnormality based on a comparison of at least three signals among the first main signal, the first sub signal, the second main signal and the second sub signal.

5 . The sensor device of claim 1 , wherein
the abnormality determiner determines abnormality based on a difference between data values respectively corresponding to the respective first main signal and second sub signal, or the respective first sub signal and second main signal, when the abnormality determiner (i) compares the first main signal with the second sub signal or (ii) compares the first sub signal with the second main signal, and the abnormality determiner determines abnormality based on a sum of data values corresponding to the respective first main signal with the first sub signal, or the respective first sub signal with the second sub signal, when the abnormality determiner (iii) comparing the first main signal with the first sub signal or the second main signal or (iv) comparing the first sub signal with the second sub signal.

6 . The sensor device of claim 1 , wherein
the abnormality determiner uses a heavier weight for (i) a comparison between the first main signal and the first sub signal or (ii) a comparison between the second main signal and the second sub signal than a weight for (iii) a comparison between (a) the first main signal or the first sub signal and (b) the second main signal or the second sub signal.

7 . The sensor device of claim 1 , wherein
the first output signal and the second output signal include a communication error detection signal.

8 . The sensor device of claim 1 , wherein
the first output signal and the second output signal include information regarding an update counter indicative of an update of data.

9 . The sensor device of claim 1 , wherein
the first main signal, the first sub signal, the second main signal, and the second sub signal are represented by a nibble.

10 . The sensor device of claim 1 , wherein
the first main sensor element, the first sub sensor element, the second main sensor element, and the second sub sensor element are respectively provided as a magnetic flux detection element that detects a change of a magnetic flux of the detection object.

11 . The sensor device of claim 10 , wherein
the first main sensor element, the first sub sensor element, the second main sensor element, and the second sub sensor element respectively detect a change of the magnetic flux according to a torque.

12 . An electric power steering device comprising:
the sensor device of claim 11 ; a motor outputting an assist torque for assisting a steering operation of a steering member by a vehicle driver; a power transmission unit transmitting the assist torque of the motor to a drive object, wherein the controller of the sensor device controls a drive of the motor based on a steering torque that is calculated based on at least one of the first main signal, the first sub signal, the second main signal, and the second sub signal.

Assignees

• Denso Corp

Inventors

• Kozawa Takaharu
• Kuramitsu Shuji
• Nakamura Koichi
• Hayashi Katsuhiko
• Taki Masaya
• Sakai Toshimitsu

Classifications

• G01R31/50

  Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections (testing of sparking plugs H01T13/58) · CPC title

• G01L25/003 Primary

  for measuring torque · CPC title

• B62D5/30

  Safety devices, e.g. alternate emergency power supply or transmission means to ensure steering upon failure of the primary steering means · CPC title

• B62D5/0463

  calculating assisting torque from the motor based on driver input · CPC title

• G01L3/101 Primary

  involving magnetic or electromagnetic means · CPC title