Optical interference range sensor

An optical interference range sensor comprising:

• a light source configured to project a light beam while continuously varying its wavelength;
• a plurality of interferometers to which the light beam projected from the light source is supplied, each of the plurality of interferometers being configured to generate an interference beam by interference between a measurement beam that is a light beam radiated toward a measurement target and reflected from the measurement target and a reference beam passing through an optical path that is at least partially different from an optical path of the measurement beam;
• a light-receiving unit comprising one or more photdetectors and a circuit configured to receive interference beams generated by the plurality of interferometers and convert the received interference beams into a plurality of electrical signals corresponding to the respective interferometers;
• and
• a processing unit comprising a processor or a processing circuit configured to perform operations comprising:
• calculating a distance from the optical interference range sensor to the measurement target based on at least one first electrical signal whose intensity is not smaller than a first threshold, of the plurality of electrical signals, and output the calculated distance;
• converting the at least one first electrical signal to a first distance value indicating a distance to the measurement target from the interferometer corresponding to that first electrical signal;
• calculating, based on the first distance value, an inclination value indicating inclination of the plurality of interferometers relative to the measurement target;
• referencing a storage unit that sequentially stores a number of times that the first electrical signal is detected, the first distance value, and the inclination value in association with each other, and correcting the first distance value based on the inclination value;
• and
• calculating a second distance value indicating the distance from the optical interference range sensor to the measurement target based on the corrected first distance value, wherein
• if the number of times that the first electrical signal is detected among the plurality of electrical signals is smaller than a second threshold, the first distance value is corrected based on an inclination value that precedes the inclination value associated with the first distance value in the storage unit.