Patent ID: 7890272
Filing Date: 2011-02-15
Classification: G01L

Abstract:
1. A torque measurement device provided with: a laser light output device outputting laser light; a light transmitting/receiving device irradiating a surface of a rotating body with the laser light from the laser light output device and also receiving reflected light thereof; a pair of reflectors which is provided on the surface of the rotating body, having a spacing in an axial direction thereof and reflects the irradiating laser light from the light transmitting/receiving device in a predetermined reflection pattern; and a signal processing device obtaining a torque of the rotating body from the reflected light received by the light transmitting/receiving device, the signal processing device, comprising: an input data storage section storing reflected light data of the laser light irradiating the surface of the rotating body, the reflected light data being input according to rotation of the rotating body; a reflector existence-region detection unit detecting existence regions of the pair of reflectors by determining a point which minimizes AIC (Akaike's information criterion) of a model for the reflected light data of the rotating body, the reflected light data being stored in the input data storage section; a twist amount calculation unit calculating a twist amount of the rotating body from reflector positions which are specified by the existence regions of the pair of reflectors, the existence regions being detected by the reflector existence-region detection unit; and a torque calculation unit calculating a torque from the twist amount of the rotating body, the twist amount being calculated by the twist amount calculation unit.