Method and apparatus for painting objects

An Apparatus for painting an object, in particular a car body part, said apparatus comprising:

• a painting head equipped with at least one spraying nozzle arranged to deliver a flow of paint of a predetermined colour on a surface of said object;
• a moving means for moving said painting head in a workspace, said moving means having at least two degrees of freedom;
• an identification device for identifying the three-dimensional shape of said surface of said object, said identification device being integral to said painting head and comprising:
• an infrared projection means arranged to project a grid, or matrix, of points on said surface of said object obtaining a projected image comprising a plurality of points;
• an optical sensor means arranged to detect said projected image on said object obtaining a detected projected image, said detected projected image comprising a plurality of points, or pixels, having determined spatial coordinates;
• a processing means arranged to receive said detected projected image from said optical sensor means and to determine said spatial coordinates of each of said points of said projected image in such a way to determine the three-dimensional shape of said surface;
• wherein said moving means is arranged to move said painting head in said workspace on the basis of said determined spatial coordinates of said points in such a way that during said painting step of said object, said spraying nozzle is arranged at a substantially fixed distance from said surface to be painted and is able to follow its curvature;
• wherein said processing means is arranged to process said three-dimensional shape to obtain a corresponding two-dimensional geometric shape, said processing means arranged to process said grey-level values of said points, or pixels, of said three-dimensional shape, and therefore the distance of said points, or pixels, from said sensor means to obtain said corresponding two-dimensional geometric shape.

A method for painting an object, said method comprising the steps of:

• arranging a painting head in a predetermined working area, said painting head equipped with at least one spraying nozzle arranged to deliver a flow of paint on a surface of an object;
• moving said painting head in said working area, said moving being carried out by moving means having at least two degrees of freedom;
• identifying the three-dimensional shape of said surface of said object, said identifying step comprising the steps of:
• projecting a grid, or matrix, of infrared points on said surface of said object, obtaining a projected image comprising a plurality of points;
• detecting said projected image obtaining a detected projected image comprising a plurality of points, or pixels, having determined spatial coordinates, said detecting step carried out by optical sensor means integral to said painting head;
• processing said detected projected image, said processing step arranged to determine said spatial coordinates of each of said points of said detected projected image in order to determine the three-dimensional shape of said object, said spatial coordinates x, y being determined on the basis of the position of each point, or pixel, in the detected projected image, said processing step comprising a step of converting said three-dimensional shape in a two-dimensional geometric shape of said surface of said object, said converting step being carried out computing the grey-level values of said points, or pixels, of said detected projected image;
• moving said painting head in said working area on the basis of said spatial coordinates of said points in such a way that during said painting step, said spraying nozzle is arranged at a substantially fixed distance from said surface of said object and can follow its curvature.