Friction identification method and friction identification device

2:

• The friction identification method according to claim 1, wherein at the step of measuring a relation between a driving force and a position of the driven object, and at the step of measuring a relation between a driving force and a displacement of the driven object from a position at which a motion direction is reversed, the driven object is moved by a predetermined movement width and stopped repeatedly within a driving range of the driven object, to synchronously measure positions of the driven object and driving forces during the repetition.

3:

• The friction identification method according to claim 1, wherein at the step of identifying a parameter of a position-dependent friction model based on a relation between a driving force and a position of the driven object, a period, during which a velocity of the driven object becomes equal to or lower than a predetermined threshold, is detected to output a friction force in the period as a position-dependent friction force at a position of the driven object.

4:

• The friction identification method according to claim 3, wherein at the step of identifying a parameter of the displacement-dependent friction model, a value that is obtained by excluding a friction force at a position of the driven object, which is calculated by using the position-dependent friction model, from the driving force is output as a displacement-dependent friction force at a displacement of the driven object.

5:

• The friction identification method according to claim 1, wherein the step of measuring a relation between a driving force and a velocity of the driven object, and the step of measuring a relation between a driving force and an acceleration of the driven object are performed simultaneously.

6:

• The friction identification method according to claim 1, wherein at the step of measuring a relation between a driving force and a velocity of the driven object and at the step of measuring a relation between a driving force and an acceleration of the driven object, the driven object is reciprocated by a predetermined movement width within a driving range of the driven object at a predetermined velocity and a predetermined acceleration, and the reciprocation is repeated while changing either a velocity or an acceleration, or changing both a velocity and an acceleration, to synchronously measure positions of the driven object and driving forces during the reciprocation.

7:

• The friction identification method according to claim 5, wherein when the step of measuring a relation between a driving force and a velocity of the driven object, and the step of measuring a relation between a driving force and an acceleration of the driven object are performed simultaneously, a sine-wave motion command is given to the driven object.

8:

• The friction identification method according to claim 1, wherein at the step of identifying a parameter of the velocity-dependent friction model, a period, during which an acceleration of the driven object becomes equal to or lower than a predetermined threshold, is detected and a value obtained by excluding both a friction force at a position of the driven object, calculated by using the position-dependent friction model, and a friction force at a displacement of the driven object, calculated by using the displacement-dependent friction model, from a friction force in the period is output as a velocity-dependent friction force at a velocity of the driven object.

9:

• The friction identification method according to claim 1, wherein at the step of identifying a parameter of the acceleration-dependent friction model, a period, during which an acceleration of the driven object is constant, is detected and a value obtained by excluding a friction force at a position of the driven object, calculated by using the position-dependent friction model, a friction force at a displacement of the driven object, calculated by using the displacement-dependent friction model, and a friction force at a velocity of the driven object, calculated by using the velocity-dependent friction model, from a friction force in the period is output as an acceleration-dependent friction force at an acceleration of the driven object.

10:

• The friction identification method according to claim 1, further comprising a step of outputting a parameter of the friction model.