Process for the automatic machine production of engineering data

A process, in which the original master diagram, which is used as the generic representation of the variation spectrum of the product and in which at least one symbol corresponds to every possible component of the product, is stored in the coded form in the memory of the information processing unit, is disclosed for the computerized generation of engineering data for products that are assembled according to individual specifications of the components. The conditions for the presence of components or of operating materials of components in an expression of the product that meets the specification are stored in the memory such that they are associated with the symbols of the original master diagram that correspond to the component or to an operating material of the component. A target engineering diagram is generated according to this process by performing a check for all symbols of the original master diagram based on the values of the specification to determine whether the corresponding conditions are met, and a decision is made based on the result of the checking (or depending on this and other factors) on whether the symbol will be taken over into the target engineering diagram (and if and when it will be taken over, how). The target engineering diagram is used as the engineering data.

FIELD OF THE INVENTION

In the industrial manufacture of products that are assembled from components according to individual specifications, the generation of the specific engineering data for each of the individually specified products is an essential process step. The information processing involved in this process step has been hitherto performed almost exclusively by humans, as a result of which this process step is time-consuming, expensive and error-prone.

BACKGROUND OF THE INVENTION

A theoretical possibility of converting graphs (graph grammars), in which a predetermined set of transformation rules is applied once or repeatedly to a root node of the graph and a complex graph is generated therefrom, has been known from the literature (e.g., Ehrig et al.: Graph Grammars and Their Application to Computer Sciences, Springer Lecture Notes CS 291, 1986). In an analogous extrapolation of this process to the area of engineering diagrams, the original master diagram could be converted into a target engineering diagram by the application of a set of rules, which act in the same way for all similar symbols and for identical symbol constellations. A conversion in which two identical symbols or symbol constellations are treated individually differently depending on external data during the transfer into the target engineering diagram is thus not possible.

Furthermore, programs and processes for putting together macrosymbols into engineering diagrams by means of rules on the basis of specification data have been known from the literature (e.g., M. Heinrich: Expert System for the Preparation of Circuit Diagrams, Automatisierungstechnische Praxis atp, Vol. 31 (1989), No. 4, pp. 190-195). However, the processes have the serious drawback that the macrosymbols must be drafted in advance and the formal and factual correctness of the engineering diagrams possibly generated during the fitting together of the macrosymbols must be ensured in advance, because the information in the macrosymbol and their connection network structure and their external connectability are not known to the rule evaluation engine and cannot be deducted. This makes decisively more difficult and increases signficantly the cost for creating and maintaining the knwoledge base and for generating the target engineering diagram.

Furthermore, various processes for determining values for variables by means of rules on the basis of data have been known from the literature (e.g., C. L. Forgy: Rete: A fast algorithm for the many pattern/many object pattern match problem, Artificial Intelligence, Vol. 19 (1982), No. 1, pp. 17-37) and from patents (e.g., DE P 30 43 563.3-53). One theoretically possible process for generating engineering data now consists of determining the components of the product on the basis of the specification by evaluating a set of rules and of subsequently determining the symbols of the components and/or their operational units from this parts list and of generating the engineering data by spatial arrangement processes known from the literature (e.g., M. May: ber das Layout netzartiger Systeme Layout of Network-like Systems , Postdoctoral Thesis, Akad. d. Wiss. der DDR,. Berlin, 1990). The process requires the setting up of general rules for designing graphs on the basis of the components. Such processes rarely attain an attractive appearance, because the effect of the placement rules is difficult to predict, and the human expert who specifies the basic knowledge has no possibility of expressing his graphic design wishes.

SUMMARY AND OBJECTS OF THE INVENTION

The primary object of the present invention is to accomplish the task of automatically generating by computer such engineering diagrams, which control the manufacturing process of the individualized product, on the basis of specification data and on the basis of the basic knowledge about the individual products that can be theoretically manufactured within a product class, in a process that can be carried out by computer, and to show how the basic knowledge is expediently represented in the memory of the information processing unit carrying out the process. The human expert formulating the basic knowledge shall now be able to determine the graphic design of the engineering data, and the problems of knowledge representation and knowledge management, which occur in the prior-art processes, shall be avoided.

This object is accomplished according to the present invention

by an original master diagram being stored in a coded form in a memory of the information processing unit, which is used as the generic representation of the variation spectrum of the product, wherein at least one symbol S i in the original master diagram corresponds to every possible component K i ,

by a coding of the condition B i , which specifies the presence of the component or of the indicated operational units of the component K i in an instantization/instance of the product that satisfies the specification, being stored in a memory of the information processing unit for each symbol S ir which corresponds to the component or to the indicated operational units of the component K i ,

by the memories being provided such that values or the attributes of the specification of the product, which attributes are included in the condition, are able to be determined from the coding of a condition B i directly or indirectly, and

by a target engineering diagram Z x being generated as specific manufacturing data for the product P x to be manufactured according to the specification X from the original master diagram by performing a check for all symbols S j of the original master diagram, for which a condition is contained in the memory, by the computerized evaluation of the associated condition B j , using the values of the attributes of the specification, to determine whether the condition B j is met, and the symbol S j is taken over into the target engineering diagram Z x only if the condition B j is met.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The invention comprises a process for the automatic, computerized generation of specific engineering data for a product to be assembled from components on the basis of attributes of the specification of the product. The attributes are stored in a memory of an information processing unit. A generic representation of the variation spectrum of the product is stored in the memory of the information processing unit. An original master diagram is used as a generic representation of the variation spectrum of the product. This key plan is stored in a coded form in a memory of the information processing unit. At least one symbol S i in the original master diagram corresponds to every possible component K i of the product. A condition B i , which specifies the presence of the component or of the indicated operational unit of the component K i in an instantiation/instance of the product that satisfies the specification, is coded and is stored in a memory of the information processing unit for each symbol S i that corresponds to the component or to the indicated operational unit of the component K i . The memories are provided such that the values of the attributes of the specification of the product, which values are included in the condition, are determined from the coding of each condition B i directly or indirectly. A target engineering diagram Z x is subsequently generated as specific engineering data for the product P x to be manufactured. This target engineering diagram Z x is generated according to the specification from the original master diagram by performing a check for all symbols S j of the original master diagram, for which a condition is contained in the memory. This is done by the computerized evaluation of the associated condition B j , using the values of the attributes of the specification, to determine whether the condition B j , is met, and the symbol S j is taken up in the target engineering diagram Z x only if the condition B j is met.

Due to the use of the master diagrams and the connections between components, which are already represented in the master diagrams graphically, it is not necessary to explicitly describe by rules the connections between components, which are necessary depending on the specification. Such a rule description was necessary in the prior art and led to a considerable conceptual and manual effort. Instead, the connections arise, in contrast, automatically in the process according to the present invention from the connection structure of the symbols in the generic (master) diagram during the computerized evaluation corresponding to the embodiments of the present invention as described below.

In one embodiment, a graphic chart, which can be interpreted as a flow chart, e.g., a circuit diagram, a signal flow chart or a process flow chart, is used as the original master diagram. The connection points the symbol has are stored in the memory of the information processing unit for each symbol individually or in the type of the symbol. The information on whether the symbol is connected to other symbols is stored in the coding of the original master diagram, which coding is contained in the memory. Before a symbol S j is taken over into the target engineering diagram, a check is performed by a computer (the information processing unit) to determine whether a target engineering diagram in which the symbol S j would be unconnected at least at one connection point would be generated by not taking over one or more other symbols directly or indirectly connected to the symbol S j in the original master diagram, and the symbol S j is not taken over into the target engineering diagram in this case.

In the evaluation based on the data of the specification, the condition B i associated with a symbol S i in the original master diagram determines whether the symbol S i will be taken over into the target engineering diagram or whether it will be omitted in the target engineering diagram, or, this depends on the type of the symbol S i whether it will be replaced with another symbol, e.g., a neutral connection symbol.

Symbols in the original master diagram, for which the computerized evaluation of the conditions of these and/or other symbols in the original master diagram reveals that they would be connected in parallel to the target engineering diagram individually or as a serially connected group to an individual neutral connection symbol or to a serially connected group of neutral connection symbols, are not taken over into the target engineering diagram.

Symbols in the original master diagram, for which the computerized evaluation of the conditions of these and/or other symbols in the original master diagram reveals that they would be bridged in the target engineering diagram with neutral connection symbols and would form a serially connected group, are replaced with an individual neutral connection symbol.

The generation of the target engineering diagram may be accompanied with computerized process steps, by which the original master diagram is converted, once or if needed, into a machine-readable form, in which each group of symbols that is coherent due to connections is translated into a system of Boolean expressions. The terms of the Boolean expressions contain the conditions associated with the symbols, and serially connected symbols or symbol groups are translated by AND'ing or translated into an AND operation on, corresponding terms, and parallel-connected symbols or symbol groups are translated by OR'ing translated into an OR operation on the, corresponding terms. These Boolean expressions are partially evaluated by computer by inserting the values for the variables in the conditions and by a systematic simplification of the Boolean expressions. The remaining nontrivial Boolean expressions are retranslated into a corresponding target engineering diagram.

The generation of the target engineering diagram may be accomplished with computerized process steps, by which the original master diagram is translated by computer, once or whenever needed, into a graph, whose links correspond to a symbol each. If necessary, repeated determinations are made by computer according to the data of the specification and the condition associated with the symbol of each link to determine whether a link is eliminated or not, and whether the two nodes connected by the link are identified with one another or not or whether nodes with exactly one afferent link and one efferent link are omitted, the two links being integrated into a single link. The remaining nontrivial partial graphs are retranslated into corresponding symbol arrangements for the target engineering diagram.