Friction identification method and friction identification device

A friction identification device that is connected to a control device which drives a motor to drive a driven object comprising:

• a position-dependent friction measurement sensor that receives a position of the driven object and a driving farce from the control device and measures a relation between a driving force and the position of driven object;
• a position-dependent friction identification module implemented by processing circuitry configured to identify a parameter of a position-dependent friction model based on a relation between a driving force and a position of the driven object;
• a displacement-dependent friction measurement sensor that receives a displacement of the driven object and the driving force from the control device, and measures a relation between a driving force and the displacement of the driven object from a position at which a motion direction is reversed;
• a displacement-dependent friction identification module implemented by the processing circuitry configured to identify a parameter of a displacement-dependent friction model by using a relation between a driving force and a displacement of the driven object, and by using the position-dependent friction model;
• a velocity-dependent friction measurement sensor that receiving a velocity of the driven object and the driving force from the control device, and measures a relation between a driving force and a velocity of the driven object;
• a velocity-dependent friction identification module implemented by the processing circuitry configured to identify a parameter of a velocity-dependent friction model by using a relation between a driving force and a velocity of the driven object, and by using the position-dependent friction model and the displacement-dependent friction model;
• an acceleration-dependent friction measurement sensor that receives an acceleration of the driven object and the driving force from the control device, and measures a relation between a driving force and an acceleration of the driven object;
• an acceleration-dependent friction identification module implemented by the processing circuitry configured to identify a parameter of an acceleration-dependent friction model by using a relation between a driving force and an acceleration of the driven object, and by using the position-dependent friction model, the displacement-dependent friction model, and the velocity-dependent friction model;
• and
• a model transmission module implemented by the processing circuitry configured to output parameters of the position-dependent friction model, the displacement-dependent friction model, the velocity-dependent friction model, and the acceleration-dependent friction model, respectively, to the control device so that the control device drives the driven object using the parameters of the friction models, each of the friction model being depending on a single state amount of the position, the displacement, the velocity, or the acceleration.

A model-based friction force correction method, comprising:

• measuring a relation between a driving force and a position of a driven object;
• identifying a first parameter of a position-dependent friction model based on a relation between a driving force and a position of the driven object;
• measuring a relation between a driving force and a displacement of the driven object from a position at which a motion direction is reversed;
• identifying a second parameter of a displacement-dependent friction model by using a relation between a driving force and a displacement of the driven object, and by using the position-dependent fiction model;
• measuring a relation between a driving force and a velocity of the driven object;
• identifying a third parameter of a velocity-dependent friction model by using a relation between a driving force and a velocity of the driven object, and by using the position-dependent friction model and the displacement-dependent friction model;
• measuring a relation between a driving force and an acceleration of the driven object;
• identifying a fourth parameter of an acceleration-dependent friction model by using a relation between a driving force and an acceleration of the driven object, and by using the position-dependent friction model, the displacement-dependent friction model, and the velocity-dependent friction model;
• and
• correcting, using processing circuitry, for an influence of the friction force on an accuracy of a contouring motion when performing feedback control for an electric motor based on the first, second, third and fourth parameters of respective friction models.