System, robot and method for measuring the color of an area of a sample or of a vehicle's part

A robot for measuring the color of an area of a sample, the robot comprising:

• a light source configured to emit light to illuminate a sample;
• an optical arrangement configured to receive said light, to output and direct a collimated beam of said light towards the sample located at a given distance, and to collect scattered light from said sample upon said illumination, the optical arrangement comprising an optical device configured to change and dynamically orient a direction of the light towards the sample thereby scanning an area of said sample, part-by-part;
• an optical spectrometer configured to receive the collected scattered light and to record an optical spectrum of the scattered light for each part;
• and
• a computing device operatively connected to the optical spectrometer;
• wherein the light emitted by the light source comprises a broad spectrum of wavelengths which are emitted simultaneously, and said broad spectrum covers, continuously, at least a band of wavelengths within the visible range, from a first wavelength to a second wavelength;
• the light emitted by the light source is spatially coherent, at least for all the wavelengths of the band from the first wavelength to the second wavelength;
• the optical arrangement, for outputting the collimated beam, is configured to preserve collimated said spatially coherent light if the latter is collimated, or said optical arrangement further comprises a collimator to perform a collimation of the spatially coherent light;
• the computing device is configured to determine color coordinates of the area of the sample in a given color space, by computing an overall optical spectrum from a statistical calculation over all or some of the optical spectra corresponding to all or some of the scanned parts of the area, and by analyzing the overall optical spectrum, said analyzing comprising calculating the XYZ Tristimulus values corresponding to said overall optical spectrum;
• and
• wherein the first wavelength is in a range between 370 nm-460 nm, and the second wavelength is in a range between 620 nm-780 nm.

A method for measuring the color of an area of a sample, comprising:

• emitting light with a light source for illuminating a sample located at a given distance by the light source, the light comprising a broad spectrum of wavelengths that are emitted simultaneously, wherein the spectrum covers continuously, at least, a band of wavelengths within the visible range, from a first wavelength to a second wavelength, the light being spatially coherent, at least at all wavelengths from the first wavelength to the second wavelength;
• receiving the spatially coherent light at an optical arrangement located at a distance from an end of the light source;
• at the optical arrangement, preserving collimated the spatially coherent light if the latter is collimated, or collimating with a collimator said spatially coherent light;
• outputting and directing, by the optical arrangement, a collimated beam of the spatially coherent light towards the sample that is located at a given distance from the optical arrangement, said distance preferably being 0.5 m or longer;
• scanning an area of the sample, part-by-part, by an optical device of the optical arrangement changing and dynamically orienting a direction of the directed collimated beam;
• recording, by an optical spectrometer, an optical spectrum of scattered light collected from the sample for each part;
• and
• measuring, by a computing device operatively connected to the optical spectrometer, color coordinates of the area of the sample in a given color space by computing an overall optical spectrum from a statistical calculation over all or some of the optical spectra corresponding to all or some of the scanned parts of the area and by analyzing the overall optical spectrum, said analyzing comprising calculating the XYZ Tristimulus values corresponding to said overall optical spectrum;
• wherein the first wavelength is in a range between 370 nm-460 nm, and the second wavelength is in a range between 620 nm-780 nm.