Positioning device and positioning method with non-contact measurement

A positioning device comprising:

• moving means for relatively moving a positioning object;
• length measuring means for measuring a distance from a constant coordinate to the positioning object in a non-contact manner and for outputting a detection signal indicating a detection position of the positioning object in which the positioning object is detected only if the positioning object is positioned in a length measuring area within a predetermined range from any detection position;
• shaft control means for stopping the moving means by detecting the detection signal from the length measuring means and automatically correcting for an overshoot amount between a stop position of the positioning object via the moving means and said detection position of the positioning object, when the moving means relatively moves the positioning object and the length measuring means;
• and
• positioning control means for storing a coordinate value after the automatic correction by the shaft control means and performing the positioning of the positioning object based on the stored coordinate value,
• wherein the overshoot amount is a distance from the detection position of the positioning object after issuing an approach stop command by detecting the detection signal from the length measuring means to the stop position of the positioning object in which the movement means is stopped, and
• wherein a numerical controller coordinate value of a main shaft from the positioning control means is read at every fixed time unit, and a correction factor with a mechanical thermal displacement as a prime cause is added using a variation amount of acquired data in moving the main shaft.

A positioning method comprising:

• measuring a distance from a constant coordinate to a positioning object in a non-contact manner using length measuring means and outputting a detection signal indicating a detection position of the positioning object in which the positioning object is detected only in a length measuring area within a predetermined range from any detection position;
• stopping relative movement of the length measuring means and the positioning object by detecting the detection signal in a stop position;
• correcting for an overshoot amount measured from the detection position of the positioning object to the stop position of the positioning object;
• and
• positioning the positioning object based on a corrected reference coordinate value obtained based on said correcting,
• wherein the overshoot amount correcting comprises:
• performing a low speed movement from a first position to the detection position of the length measuring means and acquiring a second coordinate value of a second position where the movement stops by detecting that the positioning object is out of the length measuring area, and
• moving the positioning object in a reverse direction at a predetermined speed higher than the low speed to enter the length measuring area, and moving the positioning object to the second position at the low speed from the length measuring area if a stop position at the first position is out of the length measuring area.

A positioning device comprising:

• a sensor which measures a distance from the sensor to a positioning object in a non-contact manner and which outputs a detection signal at a detection position of the positing object where the detection signal indicates that the positioning object is detected when the positioning object is in a measuring range;
• a driver which moves at least one of a positioning object and the sensor;
• a shaft controller which stops the movement of the at least one of the positioning object and the sensor in a stop position if the detection signal from the sensor is detected and which automatically corrects an overshoot amount between the stop position of the positioning object and the detection position of the positioning object in which the detection signal is output;
• a storage unit which stores a coordinate value after the automatic correction by the shaft controller;
• and
• a controller which performs positioning based on the stored coordinate value,
• wherein the shaft controller corrects the overshoot amount by performing a low speed movement from a first position to the detection position of the length measuring means and acquiring a second coordinate value of a second position where the movement stops by detecting that the positioning object is out of the length measuring area, and by moving the positioning object in a reverse direction at a predetermined speed higher than the low speed to enter the length measuring area, and moving the positioning object to the second position at the low speed from the length measuring area if a stop position at the first position is out of the length measuring area.