Arithmetic processing apparatus, distance measuring apparatus, and arithmetic processing method

A distance measuring apparatus comprising:

• a light emitting part configured for light emission of first irradiation light of which intensity is modulated by a first modulation signal of a first frequency, and light emission of second irradiation light of which intensity is modulated by a second modulation signal of a second frequency different from the first frequency;
• a light receiving part that receives reflected light that is light emitted from the light emitting part and reflected by a measurement object;
• and
• an operation processing part that performs processing of calculating a first distance to a measurement object by emitting and receiving first irradiation light, calculating a second distance to the measurement object by emitting and receiving the second irradiation light, calculating a corrected first distance using first correction data that has been acquired, determining whether the corrected first distance is within an error range of the second distance as a third distance using the second distance, determining that the third distance is considered to include an error due to noise, acquiring second correction data for correcting an error of the second distance caused by an error in an intensity change of the second irradiation light with respect to a sine wave of the second frequency, defining a corrected second distance obtained by correcting the second distance using the second correction data, defining a difference between the corrected first distance and the third distance as a first difference, defining a difference between the corrected second distance and the third distance as a second difference, and calculating an error due to the noise so that the first difference and the second difference become smaller.

An arithmetic processing method performed by an arithmetic processing apparatus, the method comprising:

• calculating a first distance to a measurement object by emitting and receiving first irradiation light of which intensity is modulated by a first modulation signal of a first frequency;
• calculating a second distance to the measurement object by emitting and receiving second irradiation light of which intensity is modulated by a second modulation signal of a second frequency different from the first frequency;
• calculating a corrected first distance using first correction data that has been acquired;
• and
• determining whether the corrected first distance is within an error range of the second distance as a third distance using the second distance;
• determining that the third distance is considered to include an error due to noise;
• acquiring second correction data for correcting an error of the second distance caused by an error in an intensity change of the second irradiation light with respect to a sine wave of the second frequency;
• defining a corrected second distance obtained by correcting the second distance using the second correction data;
• defining a difference between the corrected first distance and the third distance as a first difference;
• defining a difference between the corrected second distance and the third distance as a second difference;
• and
• calculating an error due to the noise so that the first difference and the second difference become smaller.