Computer-implemented method of estimating a mass distribution of a physical product

1 . A computer-implemented method of estimating a mass distribution of a physical product comprising a plurality of product parts represented using physical product design data stored across a plurality of data sources, in multiple data formats, the method comprising:

(i) by one or more mass estimation computers:

a) from the plurality of data sources, gathering and reorganizing the physical product design data in the multiple data formats and incrementally building, during a designing user using a design user interface operatively connected to the one or more mass estimation computers for a computer-implemented design process of said physical product, a data structure comprising, for each product part, data representing a position and orientation of the part within the product, data representing a mass of the part and, for at least some product parts, data representing part geometry in voxel format, wherein building the data structure comprises recursively converting data representing product part geometries for the at least some product parts into the voxel format;

(ii) responsive to a mass estimation user requesting the estimate of the mass distribution of the physical product in a user interface operatively connected to the one or more mass estimation computers:

b) decomposing a digital model of the physical product into a plurality of slices perpendicular to a same axis, each slice being identified by its position along the axis;

c) for each slice, using the data structure for identifying a set of product parts of the data structure wholly or partially overlapping with the slice and, for each product part of the set, determining an overlap rate of the part and the slice using the position and geometry data stored in the data structure, wherein, for the at least some product parts, the geometry data is stored in the voxel format in the data structure;

d) attributing to each slice a mass value corresponding to a sum of the masses of all product parts overlapping with the slice, weighted by the respective overlap rates; and

e) outputting, on the user interface of the one or more mass estimation computers, a mass distribution (λ) of the product along said axis having the mass value attributed to each slice of the physical product.

2 . The computer-implemented method of claim 1 wherein, in step c), at least one product part for which the data structure contains no geometry data is considered to fully overlap with a single slice, determined by the position and orientation data of the product part in the data structure.

3 . The computer-implemented method as claimed in claim 1 wherein the data structure contains, for at least one product part for which it does not contain geometry data:

data identifying a subset of the product to which said product part belongs, and

data representing the geometry of said subset of the product in n-tree voxel format;

and wherein step c) comprises identifying slices wholly or partially overlapping with the product part and the respective overlap rates based on the geometry of the subset of the product to which said product part belongs.

4 . The computer-implemented method as claimed in claim 1 , wherein said voxel format is a n-tree voxel format.

5 . The computer-implemented method as claimed in claim 1 further comprising a step of:

e2) estimating the mass distribution (λ) of the product along said axis by interpolating and smoothing the mass values attributed to the positions along the axis identifying each of said slices.

6 . The computer-implemented method as claimed in claim 1 wherein the data structure also comprises, for at least one product part, data representing a mass tolerance and wherein step d) further comprises computing a tolerance for the mass values attributed to the positions along the axis identifying each slice overlapping with said product part.

7 . A computer program product comprising:

a non-transitory computer-readable data-storage medium; and

computer-executable instructions stored on the data storage medium which when executed cause a computer system to estimate a mass distribution of a physical product having a plurality of product parts represented using physical product design data stored across a plurality of data sources, in multiple data formats, the computer system estimating the mass distribution by:

(i) by one or more mass estimation computers:

a) from the plurality of data sources, gathering and reorganizing the physical product design data in the multiple data formats and creating, during a designing user using a design user interface operatively connected to the one or more mass estimation computers for a computer-implemented design process of the physical product, a data structure comprising, for each product part, data representing a position and orientation of the part within the physical product, data representing a mass of the part and, for at least some product parts, data representing part geometry in voxel format, wherein creating the data structure comprises recursively converting data representing product part geometries for the at least some product parts into the voxel format;

(ii) responsive to a mass estimation user requesting the estimate of the mass distribution of the physical product in a user interface operatively connected to the one or more mass estimation computers:

b) decomposing a digital model of the physical product into a plurality of slices perpendicular to a same axis, each slice being identified by its position along the axis;

c) for each slice, using the data structure for identifying a set of product parts of the data structure wholly or partially overlapping with the slice and, for each product part of the set, determining an overlap rate of the part and the slice using the position and geometry data stored in the data structure, wherein, for the at least some product parts, the geometry data is stored in the voxel format in the data structure;

d) attributing to each slice a mass value corresponding to a sum of the masses of all product parts overlapping with the slice, weighted by the respective overlap rates; and

e) outputting, on the user interface of the one or more mass estimation computers, a mass distribution (λ) of the product along said axis having the mass value attributed to each slice of the physical product.

8 . A non-transitory computer-readable data-storage medium comprising:

a memory area; and

computer-executable instructions coupled to the memory area that configure a computer system to estimate a mass distribution of a physical product having a plurality of product parts represented using physical product design data stored across a plurality of data sources, in multiple data formats, the computer system estimating the mass distribution by:

(i) by one or more mass estimation computers:

a) from the plurality of data sources, gathering and reorganizing the physical product design data in the multiple data formats and creating, during a designing user using a design user interface operatively connected to the one or more mass estimation computers for a computer-implemented design process of the physical product, a data structure comprising, for each product part, data representing a position and orientation of the part within the product, data representing a mass of the part and, for at least some product parts, data representing part geometry in voxel format, wherein creating the data structure comprises recursively converting data representing product part geometries for the at least some product parts into the voxel format;

(ii) responsive to a mass estimation user requesting the estimate of the mass distribution of the physical product in a user interface operatively connected to the one or more mass estimation computers:

b) decomposing a digital model of the physical product into a plurality of slices perpendicular to a same axis, each slice being identified by its position along the axis;

c) for each slice, using the data structure for identifying a set of product parts of the data structure wholly or partially overlapping with the slice and, for each product part of the set, determining an overlap rate of the part and the slice using the position and geometry data stored in the data structure, wherein, for the at least some product parts, the geometry data is stored in the voxel format in the data structure;

d) attributing to each slice a mass value corresponding to a sum of the masses of all product parts overlapping with the slice, weighted by the respective overlap rates; and

e) outputting, on the user interface of the one or more mass estimation computers, a mass distribution (λ) of the product along said axis having the mass value attributed to each slice of the physical product.

9 . A Computer Aided Design system comprising:

a processor coupled to a non-transitory memory and a graphical user interface;

the non-transitory memory storing computer-executable instructions to cause the Computer Aided Design system to estimate a mass distribution of a physical product having a plurality of product parts represented using physical product design data stored across a plurality of data sources, in multiple data formats, the estimating being by:

(i) by one or more mass estimation computers:

a) from the plurality of data sources, gathering and reorganizing the physical product design data in the multiple data formats and creating during a designing user using a design user interface operatively connected to the one or more mass estimation computers for a computer-implemented design process of said physical product, a data structure comprising a data structure comprising, for each product part, data representing a position and orientation of the part within the product, data representing a mass of the part and, for at least some product parts, data representing part geometry in voxel format, wherein building the data structure comprises recursively converting data representing product part geometries for the at least some product parts into the voxel format;

(ii) responsive to a mass estimation user requesting the estimate of the mass distribution of the physical product in a user interface operatively connected to the one or more mass estimation computers:

b) decomposing a digital model of the physical product into a plurality of slices perpendicular to a same axis, each slice being identified by its position along the axis;

c) for each slice, using the data structure for identifying a set of product parts of the data structure wholly or partially overlapping with the slice and, for each product part of the set, determining an overlap rate of the part and the slice using the position and geometry data stored in the data structure, wherein, for the at least some product parts, the geometry data is stored in the voxel format in the data structure;

d) attributing to each slice a mass value corresponding to a sum of the masses of all product parts overlapping with the slice, weighted by the respective overlap rates; and

e) outputting, on the user interface of the one or more mass estimation computers, a mass distribution (λ) of the product along said axis having the mass value attributed to each slice of the physical product.

10 . The computer system of claim 9 , the computer system further comprising:

a server;

an end user computer; and

a plurality of computers connected over a network, the server being programmed for carrying out steps a) to d) of the estimating and the plurality of computers storing said physical product design data.

11 . The computer-implemented method of claim 1 , wherein said converting includes converting tessellated-format geometry data from said plurality of data sources to said voxel format.

12 . A non-transitory computer-readable data-storage medium storing a data structure, said data structure comprising, for each one of a plurality of product parts of a physical product, data representing a position and orientation of the part within the physical product, data representing a mass of the part and, for at least some product parts, data representing part geometry in voxel format;

wherein the data structure is incrementally built using physical product design data stored across a plurality of data sources, in multiple data formats, by one or more mass estimation computers during a designing user using a design user interface operatively connected to the one or more mass estimation computers, where building the data structure comprises recursively converting data representing product part geometries for the least some product parts into the voxel format;

wherein, responsive to a mass estimation user requesting the estimate of the mass distribution of the physical product in a user interface operatively connected to the one or more mass estimation computers, the user interface outputs a mass distribution (λ) of the product along said axis having a mass value attributed to each slide of the physical product, the mass distribution calculated by:

decomposing a digital model of the physical product into a plurality of slices perpendicular to a same axis, each slice being identified by its position along the axis;

for each slice, using the data structure for identifying a set of product parts of the data structure wholly or partially overlapping with the slice and, for each product part of the set, determining an overlap rate of the part and the slice using the position and geometry data stored in the data structure, wherein, for the at least some product parts, the geometry data is stored in the voxel format in the data structure; and

attributing to each slice a mass value corresponding to a sum of the masses of all product parts overlapping with the slice, weighted by the respective overlap rates.

13 . The computer-implemented method as claimed in claim 1 , wherein said voxel format is an octree voxel format.