Photogrammetric computer aided method for plant construction

Claim 1

A method for deriving and storing information about industrial plant structures constructed of a plurality of interrelated, three-dimensional, basic unit shapes, the method comprising: (a) taking stereo-pair photographs of the structure, (b) mounting the photographs in a photogrammetry stereo comparator having co-ordinate readout and processing means with associated data base, (c) effecting orientation procedures to correlate comparator co-ordinates to the orientation of the structure, (d) providing the processing means with a mathematical template for each kind of basic unit shape for which the information is required, each template having variable parameters sufficient fully to define the dimensions and orientation of the shape, but initially having nominal values for those parameters, (e) selecting a first template corresponding to a first unit shape and entering this first template into the data base, (f) selecting a further template corresponding to a further basic unit shape and entering this further template into the data base, (g) repeating step (f) until templates are entered into the data base for each basic unit shape about which information is required, (h) specifying in the data base the manner in which the basic unit shapes for which templates are provided, are inter-connected, (i) viewing through the stereo comparator a first basic unit shape depicted in the stereo-pain photographs and selecting the corresponding template, (j) aligning the comparator with a plurality of points on the viewed basic unit shape in turn and operating the comparator readout means to obtain the co-ordinates of those points, (k) calculating from the readout co-ordinates the true values for the variable parameters of the corresponding template, and replacing the nominal values with these calculated true values, and (1) repeating steps (i) (j) and (k) for each template selected thereby to obtain the values of the parameters for each basic unit shape and their three-dimensional interrelation in the structure.

Claim 2

A method for deriving and storing information about industrial plant structures constructed of a plurality of interrelated, three-dimensional, basic unit shapes, the method comprising: (a) taking stereo-pair photographs of the structure, (b) mounting the photographs in a photogrammetry stereo comparator having co-ordinate readout and processing means with associated data base, (c) effecting orientation procedures to correlate comparator co-ordinates to the orientation of the structure, (d) providing the processing means with a mathematical template for each kind of basic unit shape for which the information is required, each template having variable parameters sufficient fully to define the dimensions and orientation of the shape, but initially having nominal values for those parameters, (e) selecting a first template corresponding to a first unit shape and entering this first template into the data base, (f) selecting a further template corresponding to a further basic unit shape and entering this further template into the data base, (g) repeating step (f) until templates are entered into the data base for each basic unit shape about which information is required, (h) specifying in the data base the manner in which the basic unit shapes for which templates are provided, are inter-connected, (i) viewing through the stereo comparator a first basic unit shape depicted in the stereo-pain photographs and selecting the corresponding template, (j) aligning the comparator with a plurality of points on the viewed basic unit shape in turn and operating the comparator readout means to obtain the co-ordinates of those points, (k) calculating from the readout co-ordinates the true values for the variable parameters of the corresponding template, and replacing the nominal values with these calculated true values, and (1) repeating steps (i) (j) and (k) for each template selected thereby to obtain the values of the parameters for each basic unit shape and their three-dimensional interrelation in the structure.

Claim 6

A method as claimed in any one of the preceding claims in which the data base is interfaced with a graphics apparatus, to enable the interrelated basic unit shapes to be displayed graphically.

Claim 8

A method of using the information obtained about a first structure by the method as claimed in any one of the preceding claims, comprising the step of: (m) changing the values of the variable parameters in the template corresponding to an existing basic unit shape, thereby to obtain corresponding information about a second structure which differs from the first in having the said existing basic unit shape modified, moved or removed.

Claim 9

A method of using the information obtained about a first structure by the method as claimed in any one of the preceding claims, to obtain corresponding information about a modified structure which differs from the first structure by the addition of one or more basic unit shapes, the method comprising the steps of: (n) selecting a new template corresponding to a new basic unit shape to be added and entering it into the data base with nominal values for the variable parameters, (o) repeating step (n) if necessary until a new template has been entered into the data base for each new basic unit shape to be added, (p) specifying in the data base the manner in which the new basic unit shapes for which templates are provided, are to be interconnected to the existing unit shapes, and (q) entering, for each new template, true parameter values which define in each case a new basic unit shape which occupies a space not occupied or overlapped by any of the other basic unit shapes in the data base.