Patent Application
20230067801
The present invention relates to a method of operating a cell-based mobility production system.
Conventionally, an integrated mass production method of selected models centered on a conveyor has been maintained. In a conventional case, vehicles are fed in a predetermined sequence, and production is carried out by the repetitive operations in each process designated to respective vehicle models by a single work assignment until a finished vehicle is produced.
When vehicles are produced by a single work assignment designated to the respective vehicle models, a work delay occurs due to a difference in working times between vehicle models if several vehicle models are simultaneously produced (mixed production).
Accordingly, innovation in the manufacturing methods is necessary to move away from the traditional vehicle production toward quick and efficient production of a variety of vehicle models.
An example of such a manufacturing method is a cell-based smart factory. In the cell-based smart factory, a unique work may be performed in each cell, the cells may be arranged in various ways in the factory, and the schedule regarding what cells vehicle bodies to be fed will go through may be readily changed.
However, even in such a cell-based process, a well-prepared overall production plan is called for to minimize bottlenecks caused by vehicle model changes and increase production efficiency. Accordingly, a method of quick and accurate simulation and establishing of production plans in advance is needed.
The matters described above as the technical background are intended only for a better understanding of the background of the present disclosure and should not be taken as an acknowledgment that they pertain to the conventional art already known to those skilled in the art.
The present invention relates to a method of operating a cell-based mobility production system. Particular embodiments relate to a method of operating a cell-based mobility production system for promoting improvement in the operating rate and productivity of a smart factory by reassigning works required in each cell that respective vehicle bodies need to go through in consideration of determined feeding order to prevent work delays occurring at each point where vehicle models change due to different working times required to perform a process for the respective vehicle models in the operation of a smart factory system for producing various types of mobilities through a plurality of cells connected in series or parallel.
An embodiment of the present invention provides a method of operating a smart factor system for producing various types of mobilities through a plurality of cells connected in series or parallel to improve an operating rate and productivity of a smart factory by reassigning works required in each cell that respective vehicle bodies to be fed need to go through in consideration of a determined feeding order to prevent a work delay occurring at every point where vehicle models change due to different working times in performing each process for the respective vehicle models.
According to an embodiment of the present invention, there is provided a method of operating a cell-based mobility production system for producing various types of mobilities through a plurality of cells connected in series or parallel in a processor, and the method includes assigning works required in each cell that the vehicle bodies matched by respective mobility need to go through, determining a feeding order of the vehicle bodies in consideration of the assigned works, and reassigning the works required in each cell that respective vehicle bodies to be fed need to go through in consideration of the determined feeding order.
In the reassigning of the works, the works required in each cell for the vehicle bodies to be fed may be reassigned such that the total production time of the vehicle bodies to be fed according to the determined feeding order satisfies the minimum production time.
After the reassigning of the works, detecting a work delay in a specific cell when the vehicle bodies are fed according to the determined feeding order may be further included, and the reassigning of the works onward may be performed again when a work delay occurs.
In the reassigning of the works, a plurality of expected reassignments in which the works required in each cell for the respective vehicle bodies to be fed according to the determined feeding order are reassigned may be prepared, and an expected reassignment in which the total production time of the vehicle bodies to be fed satisfies the minimum production time may be selected as an optimal reassignment among the plurality of expected reassignments.
In the determining of the feeding order of the vehicle bodies, a plurality of expected production plans different from each other in the feeding order of the vehicle bodies may be prepared, and an expected production plan having the shortest working time may be selected as an optimal expected production plan among the expected production plans.
In the determining of the feeding order of the vehicle bodies, a plurality of expected production plans different from each other in the feeding order of the vehicle bodies may be prepared, and an expected production plan having the shortest standby time between the vehicle bodies to be fed may be selected as an optimal expected production plan among the expected production plans.
In the reassigning of the works, the works required in each cell for the vehicle bodies to be fed may be reassigned in consideration of the determined feeding order and workload difference between the preceding and following vehicle bodies.
In the reassigning of the works, the works required in each cell for the vehicle bodies to be fed may be reassigned in consideration of the determined feeding order and possible and impossible works in the respective cells.
According to another embodiment of the present invention, there is provided a method of operating the cell-based mobility production system for producing various types of mobilities through a plurality of cells connected in series or parallel, and the method includes assigning works required in each cell that the vehicle bodies matched by respective mobility need to go through, determining a feeding order of vehicle bodies in consideration of the assigned works, reassigning the works required in each cell that the respective vehicle bodies to be fed in consideration of the determined feeding order need to go through, and planning a logistics flow of parts required in each cell in consideration of the determined feeding order and reassigned works.
After the planning of the logistics flow, detecting an occurrence of a logistic issue including a collision or congestion in the logistics flow when the vehicle bodies are fed according to the feeding order may be further included, and the planning of the logistics flow onward may be performed again when a logistics flow issue arises.
After the planning of the logistics flow, detecting a work delay in a specific cell when the vehicle bodies are fed according to the feeding order may be further included, and the reassigning of the work onward may be performed again when a work delay occurs.
After the planning of the logistics flow, detecting the possibility or impossibility of achieving a target production amount of the mobility when the vehicle bodies are fed according to the feeding order may be further included, and the reassigning of the work onward may be performed again when achieving the target production amount is determined to be impossible.
According to the method of operating the cell-based mobility production system, in the operation of a smart factory system for producing various types of mobilities through a plurality of cells connected in series or parallel, embodiments of the present invention may promote improvement in the operating rate and productivity in a smart factory by reassigning the works required in each cell that the respective vehicle bodies to be fed need to go through in consideration of the determined feeding order to prevent a work delay occurring at every point where vehicle models change due to different working times in performing each process for the respective vehicle models.
Specific structural or functional descriptions of the embodiments of the present invention disclosed in the present specification or application are presented by way of examples only for the purpose of describing the embodiments according to the present invention, and the embodiments according to the present invention may be implemented in various forms and should not be construed as being limited to the embodiments described in the present specification or application. In the following, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
Here, a sequence SEQ refers to an order in which vehicles are fed and will be denoted by Seq hereinafter. The embodiment method of operating the present invention may be performed by a controller (processor) but is not limited thereto.
An example of the works performed in each cell shown in
As shown in TABLE 1, TE1 to TE5 may be connected in series and may form a trim line. And, PM to AM may be connected in series as a chassis line.
On the other hand, as shown in TABLE 1 and
And, FE1 to FE6 represent a final line, and final installation works may be performed in cells connected in series. As described above, the cell-based mobility production system to which embodiments of the present invention are applied has a basic assembly sequence and a cell arrangement.
The manual cell shown in
As shown in the upper part of
However, as shown in the upper part of
Specifically, as shown in the upper and lower parts of
And, as shown in the upper part of
By the way, the total working time of the processes performed in Cells 1, 2, and 3 of model B of Seq 2 is different from the total working time of the processes performed in Cells 1, 2, and 3 of model A of Seq 1 due to the difference in working process performed in each cell for the respective models (the working time for model B is assumed to be shorter than that for model A in the present embodiment).
Accordingly, if the method of operating the production system based on a single work assignment optimized for model A is applied to the mixed production system and model A of Seq 1 is processed in Cell 2 after work in Cell 1 is completed, model B of Seq 2 fed following model A may not be fed to Cell 2 and stand by immediately after work in Cell 1 is completed due to the shorter working time for model B than model A, and idle time is generated and accumulated.
That is, the difference in working times between different models is not duly considered. This phenomenon is repeated every time models change and a different model is fed. Accordingly, the production efficiency of the mobility production system may decline and the daily target production amount of mobilities may not be achieved. After all, the application of the convention production system to the mixed production system adversely affects the overall vehicle production plan.
On the other hand, as shown in the lower part of
For example, considering that the total working time and working time in Cell 1 are shorter for Seq 2 (model B), the working time of Seq1 (model A) in Cell 1 may be extended and the working time of the same in Cell 2 may be shortened. That is, the working time in each cell may be adjusted by reassigning the working process performed in each cell for the same total working time of Seq1 (model A). Accordingly, the idle time between the work completion time in Cell 1 and the work start time in Cell 2 of Seq2 (model B) is reduced.
Sequentially, work reassignment may be implemented such that the working time in Cell 2 of Seq 2 (model B) is extended and the working time in Cell 3 is shortened in consideration of Cell 1 of Seq 3 (model A) and Cell 3 of Seq 1 (model A), which have a relatively long total working time. Accordingly, the idle time between the work completion time in Cell 1 and the work start time in Cell 2 of the Seq 3 (model A) is reduced. Eventually, the total production time of mobilities is minimized when the production system of embodiments of the present invention is applied to mixed production.
In this way, the method of operating the cell-based mobility production system according to an embodiment of the present invention reassigns the works for the respective vehicles based on the vehicle feeding order to solve the basic problem of the work delay that may occur in a multi-model mixed production line. Through this, the method of operating the cell-based mobility production system according to an embodiment of the present invention prepares a flexible production plan having a high degree of freedom and promotes productivity improvement.
The lower part of
Specifically, the works may be reassigned such that the difference between the work completion time of Seq 1 (model A) in Cell 2 and the work start time of Seq 2 (model B) in Cell 2 is minimized. To this end, the works in each cell may be reassigned such that the working time of Seq 1 (model A) in Cell 2 is reduced and the working time of Seq 1 (model A) in Cells 1 and 3 is extended.
Similarly, the works may be reassigned such that the difference between the work completion time of Seq 2 (model B) in Cell 2 and the work start time of Seq 3 (model A) in Cell 2 is minimized. To this end, the works in each cell may be reassigned such that the working time of Seq 2 (model B) in Cell 2 is extended and the working time of Seq 2 (model B) in Cells 1 and 3 is reduced.
In this way, the works required in each cell for the respective vehicle bodies to be fed may be reassigned such that the total working time for vehicle bodies to be fed satisfies the minimum working time.
TABLE 2 below illustrates the works that may be reassigned to other cells among the works performed in the process of TE 1 and the other cells to which the reassignment is possible.
On the other hand, some parts in the automated process also may be reassigned to the manual process. Also, a link may be arranged such that work information and logistics information are automatically revised when the assignment is changed through this process.
As shown in TABLE 1, various types of works that may be performed in each cell may be defined. In particular, movements between cells connected in parallel entail differences in production time depending on various moving paths. In addition, the working time in a cell also differs depending on what cells the vehicle body has gone through to the present cell. Accordingly, the method of operating the cell-based mobility production system according to an embodiment of the present invention sets the optimal moving path depending on the work assignment for the respective vehicles to minimize the total production time of the vehicle bodies.
In addition,
And, in the reassigning of the works (S104), the works required in each cell for the vehicle bodies to be fed may be reassigned in consideration of the determined feeding order and sequential relationships between the respective works. And, in the reassigning of the works (S104), the works required in each cell for the vehicle bodies to be fed may be reassigned in consideration of the determined feeding order and possible and impossible works in the respective cells. That is, the works may be reassigned towards finding critical variables that minimize the object functions in consideration of various sets of constraints (sequential relationships between the respective works and impossible works in the respective cells) in the mathematical optimization model.
In addition,
On the other hand,
Here, in the assigning of the works (S102), the works may be assigned in consideration of the target production amount of each mobility. In addition, in the determining of the feeding order (S102), the feeding order may be determined in consideration of the total production time of the vehicle bodies to be fed according to the feeding order.
On the other hand,
TABLES 3 and 4 below show an example of production information, including the daily target production quantity for each process and production model, and processes that can be performed and reassigned for the respective vehicle models. TABLE 5 below shows a simulation result listing reduction rates of the overall total production time and the lead time for the respective vehicle models on the basis of a mixed production according to the determined feeding order as compared with the conventional invention (As-Is) that mathematically optimizes the work assignment based on a single vehicle model production under the constraints of TABLES 3 and 4.
In this way, the cell-based mobility production system according to the embodiment of the present invention achieves a reduction in the total production time while eliminating errors in the work assignment and the logistics flow through a digital twin simulation.
As described above, specific embodiments of the present invention are illustrated and described, but it will be self-evident to those skilled in the art that the present invention may be improved upon and modified in various ways within the scope not departing from the technical spirit of the present invention provided by the patent claims below.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0113871 | Aug 2021 | KR | national |
This application claims the benefit of Korean Patent Application No. 10-2021-0113871, filed on Aug. 27, 2021, which application is hereby incorporated herein by reference.
