METHOD OF MEASURING COORDINATES OF CENTRE AND RADIUS OF CYLINDRICAL SECTIONS OF PARTS Russian patent published in 2016 - IPC G01B5/04 

FIELD: measuring equipment.

SUBSTANCE: invention relates to means of measuring coordinates of centre and radius of cylindrical sections of parts. This method includes determining coordinates of centre of spherical tip with radius R_h of the measuring head during each touch with article surface. Measurements are performed at least at three points of circular section, for which the spherical tip center coordinates X_i and Y_i. Calculating coordinates of center B (x_b; y_b) and radius R_b of circular section in the measuring system of coordinates X_izm, Y_izm. After that, surfaces of design bases not coinciding with measuring bases are measured and characteristic points of design bases C (x_c; y_c) and D (x_d; y_d) are defined. According to characteristic points a structural system of coordinates X_kon., X_kon. is created which is displaced relative to the beginning of the measuring system of coordinates by values of x_c and y_c, and its axis are turned at the angle α. In design coordinate system the position of centre B of radius section relative to the characteristic points of design bases C and D is calculated using the following relationships: L_x=|(x_a-x_c)cosα+(y_a-y_c)sinα|; L_y=|-(x_a-x_c)sinα+(y_a-y_c)cosα|; K_x=|((x_a-x_c)cosα+(y_a-y_c)sinα)-((x_b-x_c)cosα+(y_b-y_c)sinα)|; K_y=|(-(x_a-x_c)sinα+(y_a-y_c)cosα)-(-(x_b-x_c)sinα+(y_b-y_c)cosα)|; where L_X, L_Y, K_X, K_Y are linear dimensions of the center of radius section with respect to the characteristic points of design bases. Angle α is determined by solving the optimization task F→min, which target function F is a sum of deviations of t_x, t_y, p_x, p_y of said distances from their magnitudes L_Xcep, L_Ycep, K_Xcep, K_Ycep, corresponding to middles of tolerance zones: F=t_x+t_y+p_x+p_y, t_x=|L_Xcep-L_X|; t_y=|L_Ycep-L_y|; p_x=|K_Xcep-K_X|; p_y=|K_Ycep-K_Y|, where L_Xcep, L_Ycep, K_Xcep, K_Ycep are middle parts of tolerance zones of corresponding linear dimensions in the design coordinate system: L_Xcep - the middle part of tolerance zone of the linear size CB on the abscisse axis; L_Ycep - the middle part of tolerance zone of the linear size CB at coordinate axis; K_Xcep - the middle part of tolerance zone of the linear size BD on the abscisse axis; K_Ycep - the middle part of tolerance zone of the linear size BD at ordinate axis. Task of determining relative position of centres of cylindrical sections and radii of said sections with random or partial locating at design bases was solved.

EFFECT: invention enables to determine coordinates of center and radius of cylindrical sections of parts with random locating at design bases.

1 cl, 5 dwg