In a guide apparatus having an ultrasonic motor as a driving source of a stage,
it is intended to accurately comprehend a degree of abrasion between a friction
member of a frictionally driven ultrasonic motor and a drive transmitting member
of the stage. A guide apparatus is constructed by an ultrasonic motor, a stage
capable of moving on the basis of a friction driving with the ultrasonic motor,
a position detecting means for detecting a position of the stage, a driving control
portion for outputting a driving command signal to the ultrasonic motor, a non-contact
type measuring means for measuring a position information of a friction member
in the ultrasonic motor, a slip distance measuring portion for calculating a slip
distance of the friction member in the ultrasonic motor, and a monitoring portion
1 equipped with tangential force measuring portion for calculating a tangential
force applied to a driving surface of the drive transmitting member in the stage
on the basis of the friction driving with the ultrasonic motor.
