US 7,320,253 B2 | ||
Stress detection method for sensor device with multiple axis sensor and sensor device employing this method | ||
Toshio Hanazawa, Kanagawa (Japan); Masaaki Ono, Kanagawa (Japan); Tsutomu Miyashita, Kanagawa (Japan); Hiroshi Tokunaga, Kanagawa (Japan); and Hiroshi Ishikawa, Kawasaki (Japan) | ||
Assigned to Fujitsu Media Devices Limited, Yokohama (Japan); and Fujitsu Limited, Kawasaki (Japan) | ||
Filed on Mar. 08, 2005, as Appl. No. 11/73,944. | ||
Claims priority of application No. 2004-109344 (JP), filed on Apr. 01, 2004; and application No. 2004-206434 (JP), filed on Jul. 13, 2004. | ||
Prior Publication US 2005/0229720 A1, Oct. 20, 2005 | ||
Int. Cl. G01P 15/125 (2006.01) |
U.S. Cl. 73—862.042 [73/1.37; 73/1.38; 73/1.77; 73/1.78; 73/493; 73/504.02; 73/862.043] | 11 Claims |
1. A stress detection method for a sensor device with a multiple axis sensor comprising, as the multiple axis sensor, first
and second sensors having detection axes of which are orthogonal to one other,
wherein, when the detection axis of the first sensor forms an angle θ with the axis direction in which detected stress Ax
is delivered, and the stress component of an axis direction that is perpendicular to the axis in which the detected stress
Ax is delivered as Az,
an output Apx of the axis direction of the first sensor is found as Apx=αx (Ax ×cos θ+Az×sin θ), and
an output Apz of the axis direction of the second sensor is found as Apz=αz (Ax×sin θ+Az×cos θ), and, when αx and αz are detection sensitivity coefficients of the first and second sensors respectively, the detection sensitivitycoefficient
αz of the second sensor is set as αz=αx tan θ,the difference Apx−Apz between the output Apx and output Apz is found, and the detected stress Ax is found from the
difference as Ax=(Apx−Apz)/αx(cos θ−tan θ×sin θ).
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