Patent ID: 7320253

Claim:
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=α x (Ax ×cos θ+Az×sin θ), and an output Apz of the axis direction of the second sensor is found as Apz=α z (Ax×sin θ+Az×cos θ), and, when α x and α z are detection sensitivity coefficients of the first and second sensors respectively, the detection sensitivitycoefficient α z of the second sensor is set as α z =α x 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)/α x (cos θ−tan θ×sin θ).