Patent Publication Number: US-2018039725-A1

Title: Aircraft assembly system

Description:
CROSS-REFERENCE TO PRIORITY APPLICATIONS 
     This application is a continuation of international patent application number PCT/EP2016/062364, having an international filing date of Jun. 1, 2016, which claims priority to European patent application number EP 15170092.9, having a filing date of Jun. 1, 2015. The content of the referenced applications is incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to the assembly of aircraft. More specifically, the present disclosure relates to an aircraft assembly system, a method for aircraft assembly, a program element and a computer-readable medium. 
     BACKGROUND 
     Configuration, design and assembly of an aircraft is a complex task. Computer-based tools, which are operated by a tool operator, are used to generate aircraft layouts, thereby observing customer-specific configuration data. The customer-specific configuration data allows a customer (user) to select, inter alia, interior equipment components, which are to be installed in the aircraft, as well as positions, in which the components are to be installed. 
     Such an interior equipment component may be a galley, a toilet module, a crew rest compartment, a cabin light, or a stowage compartment. The customer may also select the number of economy class passenger seats, the number of business class passenger seats and/or the number of first class passenger seats to be installed in the aircraft. 
     The customer may also select certain specific design parameters of the aircraft, such as interior equipment materials. 
     The aircraft manufacturing process, in the following also denoted as aircraft assembly, may have to meet certain process parameters, such as time of delivery, time frames for carrying out specific assembly tasks, the number of men available for working in the assembly line, manufacturing tasks to be performed, the selected elements for assembling the aircraft, availability of these elements, changes in the manufacturing chain or external events, such as non-available machines, non-available assembly halls, electric power available, material available, a reduced number of workers or the occurrence of unexpected emergencies, such as fire alarms, water damages, or storm losses. Therefore, aircraft assembly is complex. 
     BRIEF SUMMARY 
     It is an object of the present disclosure to provide for a more efficient aircraft assembly. 
     This object is achieved by the subject-matter of the independent claims. Developments of certain embodiments of the invention are stated in the dependent claims at the following description. 
     According to a first aspect of the present disclosure, an aircraft assembly system is provided, which comprises an input module, a database and a processing unit. The input module is adapted for inputting customer-specific design and/or configuration data relating to a configuration and/or a design of the aircraft and for inputting input parameters relating to at least one of expected time of delivery of the aircraft, the number of personnel working in the aircraft assembly system, an apparatus of the system which cannot be used, or resources available in the aircraft assembly system. The database comprises a set of rules for components available for installation in the aircraft, for the customer-specific design and/or configuration data, and for the input parameters. The processing unit is adapted for generating a manufacturing plan for assembling the aircraft in accordance with the set of rules. 
     The processing unit is, according to an exemplary embodiment of the present invention, also adapted for automatically varying the input parameters in order to change the manufacturing plan. 
     Such a change of the manufacturing plan may result in an improvement of the manufacturing plan, and in particular in a reduction of overall assembly costs or assembly time. 
     For example, the processing unit may be adapted for replacing an input parameter, which has been input into the system by a user, such as the expected time of delivery of the aircraft. Thus, the time of delivery may be changed to a future time or to an earlier time and, as a consequence, the expected time of delivery of another aircraft may also be changed, such that the resources available are used in the most efficient manner. 
     According to another exemplary embodiment of the present invention, the processing unit is further adapted for automatically varying the customer-specific design data and/or configuration data in order to change the design and/or the configuration of the aircraft and/or the manufacturing plan. 
     For example, the processing unit may be adapted for replacing components a user has selected for installation in the aircraft, by inputting respective customer-specific design and/or configuration data relating to that component, by other components, which differ from the selected components. Such a replacement may improve the overall design and/or configuration of the aircraft, or the manufacturing plan, or it may reduce the overall production/assembly costs and/or maintenance costs, or other properties of the aircraft, such as mechanical properties. 
     In other words, the system may be capable of generating aircraft manufacturing plans, which may include aircraft designs and configurations, which differ from what the user has initially selected, in particular if the changed design/configuration/manufacturing plan of the aircraft provides advantages over the prior design/configuration/manufacturing plan. Reasons for such an improvement may be that the new aircraft is less heavy, less costly, consumes less fuel, has an improved center of gravity position (which may help to save fuel), provides more passenger seats or storage space as compared to the prior aircraft, and/or is produced at reduced costs or by using a reduced amount of resources/time. 
     The system may use description logics for generating the manufacturing plan. More specifically, the system may use ontologies for generating the manufacturing plan. The ontologies may be defined by the description logics. The ontologies, and as a consequence also the description logics, define the types, properties and interrelationships of the components of the aircraft and of the input parameters. 
     The design data may comprise information about a specific design of a component of the aircraft to be installed in the aircraft, such as a shape or a material of the component. 
     Configuration data may comprise information about a type of the component to be installed in the aircraft or about a position, at which the component is to be installed in the aircraft. 
     It should be noted that the component may also be a “void space”, where no interior equipment is to be installed. 
     The set of rules may comprise description logics for each component to be installed in the aircraft. In other words, each component may be related to a specific set of logical statements and rules, which defines the interrelation of the components to other components of the aircraft, and possible positions of installation thereof in the aircraft. These possible positions of installation may be related to a specific set of logical statements and rules, which defines the interrelation of the positions of installation to the whole cabin, to a door zone or a further dedicated sub-zone in the aircraft, for example. 
     The set of rules may also comprise description logics for the input parameters. 
     According to another exemplary embodiment of the present invention, the database comprises rules for components which are not available for installation in the aircraft, wherein the processing unit is adapted for selecting the specific set of rules for the components which are available for installation in the aircraft in the database and other rules which relate to different components are not selected. This selection may save computational costs during generation of the manufacturing plan. 
     According to another exemplary embodiment of the present invention, the processing unit is adapted for controlling an assembling apparatus of the aircraft assembly system, which apparatus is configured to assemble a part of the aircraft, in accordance with the manufacturing plan. 
     According to another exemplary embodiment of the present invention, the processing unit is further adapted for prioritizing the input parameters, and for changing only an input parameter which is of low priority. 
     According to another exemplary embodiment of the present invention, the set of rules comprises a sub-set of deterministic rules, which do not allow varying a position information of a component or an input parameter relating to that sub-set. Further, the set of rules comprises a second sub-set of non-deterministic rules, which do allow varying an input parameter relating to that sub-set. 
     Thus, only the non-deterministic rules may allow variations by the processing unit. The deterministic rules may not allow for such variations. Both groups of rules have to be observed at all times, at least according to this exemplary embodiment. 
     The system may be adapted for allowing a customer to select both, deterministic and non-deterministic rules, which are to be observed during generation of the manufacturing plan. The system may also be capable of allowing a user to change a non-deterministic rule into a deterministic rule. There may also be deterministic rules, which the user is allowed to disregard, in which the system does not observe them at all. However, there are also deterministic rules, which have to be observed at all times and cannot be disregarded, even if the user would like to do so. 
     According to an exemplary embodiment of the present invention, at least some of the rules of the set of rules describe ontologies of the components and input parameters and are based on description logics. 
     According to another exemplary embodiment of the present invention, the processing unit is further adapted for prioritizing the rules to be observed, wherein a rule which is of low priority is disregarded, if observing one or more of the low priority rules would result in a manufacturing plan which contravenes a higher priority rule. For doing so, the processing unit may observe key performance indicators, such as overall costs, fuel consumption, weight, and the system may be adapted to decide which rules need a higher prioritization than other rules. It should be noted that the priority of a specific rule may change if a component of the aircraft is replaced by another component, or if an input parameter is changed. 
     According to another exemplary embodiment of the present invention, the processing unit is adapted for performing an error check of the manufacturing plan generated, and for automatically varying the input parameters in order to correct the error or in order to improve the plan. 
     According to another exemplary embodiment of the present invention, the manufacturing plan also comprises testing tasks, i.e. time intervals reserved for testing one or more components of the aircraft during assembly of the aircraft. 
     According to another aspect of the present disclosure, a method for aircraft assembly is provided, in which customer-specific design and/or configuration data relating to a configuration and/or a design of the aircraft is input. Further, input parameters relating to at least one of expected time of delivery, the number of personnel working in the aircraft assembly system, an apparatus of the system which cannot be used or resources available in the aircraft assembly system are input. Further, a set of rules for components available for installation in the aircraft, for the customer-specific design and/or configuration data, and for the input parameters is provided. Then, a manufacturing plan for assembling the aircraft is generated in accordance with the set of rules. 
     Another aspect of the disclosure relates to a program element which, when being executed by a processor of an aircraft assembly system, instructs the processor to carry out the following steps: receiving customer-specific design and/or configuration data relating to a configuration and/or design of the aircraft, receiving input parameters relating to at least one of expected time of the delivery, the number of personnel working in the aircraft assembly system, an apparatus of the system which cannot be used or resources available in the aircraft assembly system; receiving a set of rules for components available for installation in the aircraft, for the customer-specific design and/or configuration data, and for the input parameters; and generating a manufacturing plan or assembling the aircraft in accordance with the set of rules. 
     According to another aspect of the disclosure, a computer-readable medium is provided, which comprises the above described program element. 
     A computer-readable medium may be a floppy disk, a hard disk, a CD, a DVD, an USB (Universal Serial Bus) storage device, a RAM (Random Access Memory), a ROM (Read Only Memory) and an EPROM (Erasable Programmable Read Only Memory). A computer-readable medium may also be a data communication network, for example the Internet, which allows downloading a program code. 
     These and other aspects of the present disclosure will become apparent from and elucidated with reference to the embodiments described hereinafter. 
     This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the present invention will now be described in the following, with reference to the following drawings. The illustration in the drawings is schematic. In different drawings, similar or identical elements are provided with the same reference numerals. 
         FIG. 1  shows an aircraft assembly system according to an exemplary embodiment of the present invention. 
         FIG. 2  shows a final assembly line of an aircraft assembly system according to an exemplary embodiment of the present invention. 
         FIG. 3  shows a manufacturing plan generation according to an exemplary embodiment of the present invention. 
         FIG. 4  shows the manufacturing plan generation according to an exemplary embodiment of the present invention. 
         FIG. 5  shows a plurality of ontologies according to an exemplary embodiment of the present invention. 
         FIG. 6  shows a flow-chart of a method according to an exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is merely exemplary in nature and is not intended to limit application and uses. Furthermore, there is no intention to be bound by any theory presented in the preceding background or summary or the following detailed description. 
       FIG. 1  shows an aircraft assembly system  100 . The aircraft assembly system  100  comprises an input module  101 , for example a workstation or a notebook. The input module  101  is adapted for inputting customer-specific design and/or configuration data, and also input parameters, such as an expected time of delivery, the number of personnel working in the aircraft assembly system, time modules etc. Further, a database  102  is provided which comprises a set of deterministic and non-deterministic rules for components available for installation in the aircraft, for the customer-specific design or configuration data, and for the input parameters. 
     The database and the input module are connected to a processing unit  103  which generates a manufacturing plan for assembling the aircraft in accordance with the set of rules and in accordance with the parameters input by the user as well as the customer-specific design or configuration data. Also connected to the processing unit  103  is a final assembly line  104  and one or more preassembly lines  105 . The manufacturing plan is used for controlling the preassembly line and the final assembly lines and for assigning resources, such as workers, machinery and assembly stations for aircraft assembly. 
     The system is capable of automatically generating a plurality of valid assembly schedules (which are part of the assembly plans), thereby observing different requirements and standard time modules. 
     Generation of the assembly plan is done with the help of description logics, which finds an optimum solution, i.e., an optimum manufacturing plan out of a huge solution set. All feasible production scheduling relationships are identified, according to the set of rules and the requirements of the specific user/manufacturer. Also, the most important performance indicators may be considered when generating the manufacturing plan, for example, overall cost, time of delivery, etc. 
     The complexity of the manufacturing process may depend on the cabin characteristics, which may also lead to different time frames. 
       FIG. 2  shows a final assembly line of an aircraft assembly system. The final assembly line  104  comprises an assembling apparatus  205 , which assembles a part  201  of an aircraft  201 ,  202 ,  203 . 
     This assembly apparatus  205  is controlled by the processing unit  103  (see  FIG. 1 ). 
       FIG. 3  shows the generation of three different manufacturing plans  303 ,  304 ,  305 , in accordance with input parameters and events  301  and in accordance with a set of rules  302  described by description logics. 
     The three manufacturing plans differ from each other, for example by assigning different manufacturing time slots (t 1 , t 2 , . . . ) and/or locations for specific assembly tasks. 
     The first manufacturing plan  303  has been generated by using the customer-specific design or configuration data and also the parameters, which have been input by the user, without any variations performed by the system. 
     The two following manufacturing plans  304 ,  305  have been generated by varying one or more of the customer-specific design or configuration data or one or more of the input parameters. The third manufacturing plan  305  may be the final manufacturing plan because it provides the most efficient aircraft assembly, although it uses slightly different input parameters and/or customer-specific design or configuration data. 
     In other words, the system may be programmed to produce a (slightly) different aircraft and/or to use different resources or timeslots than the ones, which have been selected by the user, in order to improve the final result. These changes may also affect assemblies of other aircraft, i.e., aircraft which have been ordered by different customers/users. 
       FIG. 4  shows the generation of a manufacturing plan according to an exemplary embodiment of the present invention. Input parameters, such as a “To-do-list”  401 , which relate to requirements and constraints, such as an expected time frame, the number of workers available, tasks to be carried out, etc., are input by a user. Further, a database is provided, which comprises a set of rules  402  to be applied. By using description logics  403 , a manufacturing plan  404  is generated, which may comprise a station schedule. Also, stations in the final assembly line may be identified in module  405 , where the final assembly of the aircraft is going to take place. Still further, all final assembly lines  406  may be assigned or even re-assigned, wherein each final assembly line may be assigned to a particular, individual aircraft. 
     Each input parameter may comprise sub-categories, for example more detailed manufacturing tasks, such as electrical, mechanical or hydraulic tasks and testing, time groups, such as hours, days, weeks, seconds or even sub-seconds, testing tasks, or concrete changes in the manufacturing chain. These parameters are linked with each other in form of implicit and/or explicit rules and specific and logical sequences. 
     Furthermore, the input parameters that manage the manufacturing process may have an influence on the whole assembly process. Therefore, the definition of a manufacturing plan may require a general and precise overview of every issue involved and a concrete background of the consequences that may appear, if some parameters change, for example interdependencies within the assembly process. 
     Generation of the manufacturing plan may be performed in a flexible manner, so that a holistic manufacturing process may be mapped in sub-models and only a part of the whole process may be considered, for example only processes relating to electric installations within the manufacturing process. 
     In order to map the integral knowledge about the manufacturing process and to offer an optimized manufacturing process according to the defined input parameters, in-process parameters and output or evaluation parameters (KPI), rules, or different options, the aircraft assembly system may be capable of taking into account all these different parameters for generating the manufacturing plan. 
       FIG. 5  shows possible links between domain ontologies. If several ontologies are taken into account, there may be the possibility to have an overall or detailed report of performance indicators, for example cost. 
       FIG. 6  shows a flow-chart of a method according to an exemplary embodiment of the present invention. In step  601 , customer-specific design and/or configuration data, which relate to a configuration and/or design of the aircraft, are input into the system. In step  602 , input parameters which relate to the expected time of delivery, number of personnel working in the aircraft assembly system, an apparatus of the system which cannot be used or resources available in the aircraft assembly system are input into the system. 
     In step  603 , a set of rules is provided for components available for installation in the aircraft, for the customer-specific design and/or configuration data, and for the input parameters. In step  604 , these rules are applied to the customer-specific design and/or configuration data and the input parameters in order to generate a manufacturing plan for assembling the aircraft in accordance with the set of rules. In step  605 , the manufacturing plan is analyzed and one or more input parameters are altered, after which the manufacturing plan is generated once again. 
     In other words, by applying description logics, the processing unit generates a manufacturing plan in accordance with a set of rules and the input parameters. In order to improve the manufacturing plan, input parameters may be changed by the system in an iterative process. This may provide for an efficient use of resources available. 
     The new manufacturing plan is then compared to the older manufacturing plan in step  606 , after which it is decided, which manufacturing plan is referred, for example because it provides a more efficient aircraft assembly. After that, the method may continue with step  605 , in which one or more input parameters are changed again, resulting in a new manufacturing plan. If the system is satisfied the generated manufacturing plan, the method continues with step  607 , in which the aircraft is assembled. 
     It should be noted that the term “comprising” does not rule out a plurality. It should further be noted that features described with reference to one of the above exemplary embodiments can also be used in combination with other features of other exemplary embodiments described above. Moreover, while at least one exemplary embodiment has been presented in the foregoing summary and detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated, that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the functional arrangement of elements described in an exemplary embodiment without departing from the scope as set forth in the appended claims and their legal equivalence.