a device including : a command - generator outputting a drive command signal to a drive unit ; a detector outputting a position - detection signal of the drive unit ; a drive - current detector outputting a drive - current detection value ; a controller receiving the drive command and position - detection signals to generate a drive - force command signal , and supplying the drive current according to the drive - force command signal and the drive - current detection value ; a friction - characteristics - estimator receiving a drive force signal and the position - detection signal to output a friction - characteristics estimate value ; a temperature - information acquirer outputting a temperature information value ; a friction modeling unit having a set reference friction model having temperature - dependent characteristics , and outputting reference friction characteristics based on the temperature information value ; and a friction - variation analyzer outputting a friction variation value based on variation of the friction - characteristics estimate value from the reference friction characteristics .