Sensor output correcting device

• US 8,306,767 B2
• Filed: 06/16/2008
• Issued: 11/06/2012
• Est. Priority Date: 09/03/2007
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Yamashita, Toshiyuki
• Primary Examiner(s): SUGLO, JANET L
• Application Number:
  US12/666,201
• Publication Number:
  US 20100191494A1
• Time in Patent Office: 1,604 Days
• Field of Search: 702/87, 702/88, 702/104, 702/106
• US Class Current: 702/87
• CPC Class Codes: B60R 2021/01129 Problems or faults
• CPC Class Codes: B60R 21/0132 responsive to vehicle motion parameters , e.g. to vehicle longitudinal or transversal deceleration or speed value
• CPC Class Codes: G01D 3/02 with provision for altering or correcting the law of variation
• CPC Class Codes: G01P 15/08 with conversion into electric or magnetic values
• CPC Class Codes: G01P 21/00 Testing or calibrating of apparatus or devices covered by the preceding groups

Abstract

A sensor output correcting device includes: a sensor element for detecting a variation in an object to be measured, and for outputting this variation as a signal; an A/D converter for converting the analog signal outputted from the sensor element into a digital signal; a zero reference value calculating unit for calculating a zero reference value which is a drift amount of the sensor element from the signal outputted from the sensor element; a zero point correcting unit for correcting a zero point of the signal outputted from the A/D converter on the basis of the zero reference value calculated by the zero criterion calculating unit; an output limiting unit for limiting a value of an output signal inputted from the zero point correcting unit on the basis of a correction amount provided by the zero point correcting unit, and a high frequency removing unit for removing a high frequency component.

Claims

1. A sensor output correcting device comprising:

a sensor element for detecting a variation in an object to be measured, and for outputting this variation as an analog signal;

an A/D converter for converting the analog signal outputted from said sensor element into a digital signal;

a zero point correcting unit for correcting a zero point of the signal outputted from said A/D converter based on a correction amount; and

an output limiting unit for limiting a value of an output signal inputted thereto from said zero point correcting unit on a basis of the correction amount, wherein said output limiting unit comprising;

a first clip processing unit for, when the signal outputted from said zero point correcting unit has a value equal to or larger than a value which said first clip processing unit has acquired by subtracting a minimum value of an output range of said A/D converter from said correction amount, outputting the value which is the subtraction of said minimum value from said correction amount; and

a second clip processing unit for, when a value outputted from said first clip processing unit is equal to or smaller than a value which said second clip processing unit has acquired by subtracting a maximum value of the output range of said A/D converter from said correction amount, outputting the value which is the subtraction of said maximum value from said correction amount.

2. The sensor output correcting device according to claim 1, wherein when said correction amount is smaller than a predetermined value, said output limiting unit does not perform the output limitation.

3. A protection system used for a moving object, comprising:

a sensor output correcting device including a sensor element for detecting a state variation in the moving object, and for outputting this variation as an analog signal, an A/D converter for converting the analog signal outputted from said sensor element into a digital signal, a zero point correcting unit for correcting a zero point of the signal outputted from said A/D converter based on a correction amount, and an output limiting unit for limiting a value of an output signal inputted thereto from said zero point correcting unit on a basis of the correction amount; and

a determining device for determining whether or not to activate a protection member for protecting an object to be protected on a basis of a signal outputted from said sensor output correcting device,

wherein said output limiting unit comprising;

a first clip processing unit for, when the signal outputted from said zero point correcting unit has a value equal to or larger than a value which said first clip processing unit has acquired by subtracting a minimum value of an output range of said A/D converter from said correction amount, outputting the value which is the subtraction of said minimum value from said correction amount; and

a second clip processing unit for, when a value outputted from said first clip processing unit is equal to or smaller than a value which said second clip processing unit has acquired by subtracting a maximum value of the output range of said A/D converter from said correction amount, outputting the value which is the subtraction of said maximum value from said correction amount.