Patent ID: 7124045
Filing Date: 2006-10-17
Classification: G05D

Abstract:
1. A displacement amount measuring device, which measures a displacement amount of a movable body by using a displacement sensor outputting a sensor signal having a value corresponding to the displacement amount of the movable body, the device comprising: a displacement amount computing component for computing the displacement amount of the movable body by using a predetermined computational method and on the basis of the value of the sensor signal outputted from the displacement sensor; a timing component for detecting sampling points, said sampling points being points in time at which the movable body is positioned at each of a plurality of predetermined reference positions; a sampling component for acquiring sample values corresponding to the respective reference positions, said sample values being values of the sensor signal, which are outputted from the displacement sensor at the respective sampling points detected by the timing component; and a correcting component for, on the basis of the plurality of sample values that are acquired by the sampling component and respectively correspond to the plurality of reference positions, computing a trend in changes over time of a characteristic of the displacement sensor, and for correcting the computational method of the displacement amount computing component in accordance with the computed trend in changes.