CN113609759B - Reconfigurable flexible assembly line layout method and device - Google Patents
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Abstract
The invention discloses a reconfigurable flexible assembly line layout method and a device, wherein the method comprises the following steps: s1, designing a reconfigurable flexible assembly line which takes a reconfigurable flexible assembly unit as a core component and can be quickly reconfigured; s2, a corresponding problem assumption and a mathematical model with multiple optimization targets are proposed according to the reconfigurable flexible assembly line; and S3, solving the mathematical model by utilizing a prepositive optimization operator and a double population genetic algorithm to obtain the reconfigurable flexible assembly line layout. The invention can reconstruct the assembly tool, the assembly fixture and the like of each assembly unit according to different assembly processes of products so as to realize the rapid reconstruction of the assembly environment.
Description
Technical Field
The invention relates to the field of automatic assembly, in particular to a reconfigurable flexible assembly line layout method and device.
Background
The existing rigid or most automatic production equipment is generally a special assembly line, and is suitable for products with large yield and stable requirements. Under the market environment that the products are increasingly personalized and the iteration speed is increased, the production mode is gradually changed into various types-small batches, and the special assembly line has the defects of high transformation difficulty, high cost, long time and the like in face of the assembly requirements of different types of products. In order to adapt to various-small batch production modes, the assembly line can be automatically and quickly reconfigured according to different product assembly processes, and the flexibility of the assembly line is improved.
The reconfigurable flexible assembly line is based on the characteristics of a flexible manufacturing system FMS and a reconfigurable manufacturing system RMS, and aims to obtain a special assembly line suitable for the product through quick reconfiguration according to different assembly processes of the assembled product, and has the advantages of flexibility and low cost. The patent CN211672695U proposes a modularized reconfigurable flexible shoemaking production line, each station can automatically complete the operation without the participation of people, and meanwhile, independent production units can be formed into a unified production line, so that the reusability of production equipment is greatly improved, and the working efficiency is improved. Patent CN109894929a provides a modular reconfigurable flexible production method and system, mainly comprising: order scheduling, route planning, reconstruction and processing, and the whole production system can be reconstructed in real time according to order information to obtain a new configuration so as to realize the production requirement of flexible customization. Patent CN105252180a discloses a reconfigurable automatic flexible welding production platform and an operation method thereof, which can redesign the production capacity according to the high flexibility requirement of automatic welding production of various small assembly parts, and realize coordination of the production task and the production capacity.
It follows that reconfigurable flexible manufacturing techniques have gained widespread attention and application in the manufacturing field, but have been less studied and patented in the product assembly field. The team has designed a kind of reconfigurable flexible assembly unit (patent CN 110238621B), its most obvious characteristic is that each unit is completely identical from the aspect of physical carrier or function implementation, so the reconfiguration of assembly tool and assembly fixture of each assembly unit can be completed quickly according to different assembly processes of the product. To realize the reconstruction of the rapid assembly environment, the important technical problems of how to calculate the number of assembly units, reasonably distribute assembly procedures and layout assembly units according to the assembly process of the given product and achieve the maximum equipment balance rate are also needed to be solved.
Disclosure of Invention
The invention aims to provide a reconfigurable flexible assembly line layout method and device, which can reconstruct an assembly tool, an assembly fixture and the like of each assembly unit according to different assembly processes of products so as to realize the quick completion of the reconstruction of an assembly environment.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
a method of reconfigurable flexible assembly line layout, comprising the steps of:
s1, designing a reconfigurable flexible assembly line taking a reconfigurable flexible assembly unit as a core component part;
s2, a corresponding problem assumption and a mathematical model with multiple optimization targets are proposed according to the reconfigurable flexible assembly line;
and S3, solving the mathematical model by utilizing a prepositive optimization operator and a double population genetic algorithm to obtain the reconfigurable flexible assembly line layout.
Further:
in step S1, the reconfigurable flexible assembly unit includes a robot, an assembly tool and a tool rack, an assembly jig and a jig base, and a tray; the robot is located in the center of the workbench, and the assembling tool, the tool rack, the assembling clamp, the clamp base and the tray are in annular layout on the workbench.
Further:
the robot is used for completing the assembly action on the reconfigurable flexible assembly unit;
in the assembling tool and the tool rack, the assembling tool is stored on the tool rack and can be arranged at the tail end of the robot for assembling parts;
the assembly fixture is arranged on the fixture base and is used for fixing and positioning the parts;
the assembly tool and the assembly fixture are matched with an assembly task to be completed on the reconfigurable flexible assembly unit; the tray is used for containing parts required in assembly and conveyed by a peripheral material conveying system.
Further:
the working process of the reconfigurable flexible assembly line comprises the following steps: before assembly begins, the number of the reconfigurable flexible assembly units is determined, the required assembly tools and the required assembly jigs are determined according to the assembly process of products, then an AGV trolley conveys the required assembly tools and the required assembly jigs to the reconfigurable flexible assembly units from an assembly tool library and an assembly jig library respectively and is configured on a tool rack and a jig base respectively, and parts are placed in a tray on a workbench by a material conveying system; when assembling is started, the robot takes out the part from the inlet tray, places the part in a clamp to clamp and assemble, and then carries out the next assembling process; after all the assembly procedures on the reconfigurable flexible assembly unit are completed, the semi-finished product is moved to an outlet tray, and the semi-finished product is moved to an inlet tray of the next reconfigurable flexible assembly unit by a transfer robot, so that the whole assembly process is sequentially completed.
Further:
the problem assumption in step S2 includes:
s2-1, all working procedures are minimum operation elements and are not subdivided;
s2-2, each assembly process can be distributed to any work station, but the same assembly process cannot be distributed to a plurality of different work stations;
s2-3, the priority relation among the working procedures is known and fixed and is determined by a priority relation diagram, so that the assembly working procedures distributed to the working stations also strictly accord with the priority constraint relation;
s2-4, the working procedure time is fixed and is determined according to actual conditions;
s2-5, neglecting loading and unloading time and starting time of a robot;
s2-6, the clamp replacement time and the transfer time of the transfer robot are ignored.
Further:
the optimization targets of the mathematical model in the step S3 comprise the production takt CT, tool replacement time RT and workbench cost ST;
min w 1 *CT+w 2 *RT+w 3 *ST
wherein w is 1 、w 2 、w 3 Respectively the weights of the corresponding considerations.
Further:
the mathematical model of the tact CT in step S2 is:
the constraint conditions are:
wherein, CT is the production beat; i, j is the number of the assembly process, i, j=1, 2, …, n; k is the workstation number, k=1, 2, …, m; n is the total number of assembly procedures; m is the total number of workstations, namely the total number of robots; t is t i The time of the step i; pre (i) is a set of direct pre-processes for task i; decision variable x ik Is that
The mathematical model of the tool change time RT is:
the constraint conditions are:
wherein RT is the assembly tool change time; RTI is the time required to replace a tool once; the decision variable Tool (i, j) is
Decision variable P (i, j) is
The mathematical model of the table cost ST is:
ST＝STI·(n+S)
wherein ST is the total cost of the reconfigurable flexible assembly unit; STI is the cost of one of the reconfigurable flexible assembly units; s is the increased number of said reconfigurable flexible assembly units.
Further:
the pre-optimization operator in step S3 performs "splitting" on the assembly procedure with a relatively long assembly time, so that the assembly time of the procedure is reduced, and thus the number of reconfigurable flexible assembly units that can be additionally increased in one workstation is calculated.
Further:
the main implementation process of the double population genetic algorithm in the step S3 comprises the following steps:
s3-1, coding: the method comprises the steps of encoding a chromosome by adopting an operation element sequence encoding mode, and photographing operation elements into a row according to a priority relation, wherein each operation element corresponds to a gene position to form an individual;
s3-2, decoding: on the premise of meeting the process priority relation, sequentially distributing the processes to the workstations;
s3-3, initializing a population: initializing a population by adopting a random method;
s3-4, fitness function: namely a multi-objective optimization function;
s3-5, selecting, crossing and mutating operators: and selecting excellent individuals through comparison of fitness functions, and realizing the superior and inferior elimination.
The invention also provides a reconfigurable flexible assembly line layout device, and the reconfigurable flexible assembly line layout is obtained by using the method.
The invention has the following beneficial effects:
1. the reconfigurable flexible assembly line layout device provided by the invention can be applied to actual production and is suitable for assembly of small-batch multi-variety production modes;
2. the layout method of the reconfigurable flexible assembly line provided by the invention can make reasonable assumptions according to the characteristics of the assembly line and provide a mathematical model, thereby laying a foundation for continuing to deeply study after the field;
3. the reconfigurable flexible assembly line layout method provided by the invention adopts a prepositive optimization operator and an improved double-population genetic algorithm to solve the mathematical model, so that a more optimized feasible solution is further obtained.
Drawings
FIG. 1 is a schematic view of a reconfigurable flexible assembly unit of an embodiment of the invention;
FIG. 2 is a diagram showing a priority relationship obtained according to an actual assembly process in an embodiment of the present invention;
FIG. 3 is a diagram showing a priority relationship after splitting a critical process in an embodiment of the present invention;
FIG. 4 is a process distribution diagram of an embodiment of the present invention;
FIG. 5 is a logical layout of a workstation according to an embodiment of the present invention;
fig. 6 is a physical layout diagram of a workstation according to an embodiment of the present invention.
Detailed Description
The invention is further described by means of specific embodiments in connection with the accompanying drawings. The following examples are only for the purpose of more clearly illustrating the technical aspects of the present invention and are not to be construed as limiting the scope of the present invention.
It should be noted that, the directions or positional relationships indicated by the left, right, upper, lower, top, bottom, etc. in the present embodiment are those based on the directions or positional relationships shown in the drawings, and are merely for convenience in describing the embodiments of the present invention and simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific direction, be configured and operated in a specific direction, and thus should not be construed as limiting the present invention.
The embodiment of the invention provides a layout method of a reconfigurable flexible assembly line, which mainly comprises the following three parts:
1. design a reconfigurable flexible assembly line with quick reconfiguration capability
The main content of the section is to design a reconfigurable flexible assembly line with rapid reconfiguration capability, and the core component of the reconfigurable flexible assembly line is a reconfigurable flexible assembly unit, and a physical carrier is also called a workbench. The physical diagram of the reconfigurable flexible assembly unit is shown in figure 1 and is mainly divided into the following four parts:
(1) Robot 101: is mainly responsible for the completion of the assembly action on the reconfigurable flexible assembly unit.
(2) Replaceable assembly tool and tool holder 102: an assembly tool is disposed at the end of the robot 101 for assembling the parts. When the assembled parts are different, this can be achieved by changing different assembly tools. The assembly tools on the unit are temporarily stored on the tool rack.
(3) Replaceable assembly jig and jig base 103: the assembly fixture is arranged on the fixture base and is used for fixing and positioning the parts. When assembling different kinds of parts, different assembly jigs can be replaced.
(4) Tray 104: for containing the parts required for assembly, which are transferred by a peripheral material handling system into the tray 104.
Based on the quick change device, different types of assembly tools can be installed at the tail end of the robot 101, and different types of assembly jigs can be configured on the jig base, so that various assembly actions can be completed. The assembly tool and the assembly fixture are matched with the assembly task to be completed on the assembly unit, and the tray 104 is responsible for loading the parts.
In addition to the assembly units, the assembly line includes an assembly tool library, an assembly jig library, a transfer robot, and an AGV trolley. The assembly tool library is used for storing all kinds of assembly tools, the assembly fixture library is used for storing all kinds of assembly fixtures, and the transfer robot is used for transferring semi-finished products among all assembly units. AGV (Automatic Guided Vehicle) is an automated guided vehicle, also called an automated guided vehicle, which is used to remove and replace assembly tools and assembly fixtures from and to a tool magazine and fixture magazine, respectively.
The procedure for the reconfigurable flexible assembly line is described as follows:
the main working process of the reconfigurable flexible assembly line comprises the following steps: the reconfigurable assembling unit is centered on a 6-degree-of-freedom assembling robot, and the workbench is in an annular layout. Before assembly begins, determining the number of assembly units, and determining required assembly tools and assembly fixtures according to the assembly process of the product; and then the AGV trolley conveys the required assembly tools and assembly clamps to each assembly unit from the assembly tool library and the assembly clamp library respectively, the assembly tools and the assembly clamps are arranged on the tool rack and the clamp base respectively, and the parts are placed in the trays on the workbench by the material conveying system, so that the assembly preparation work is completed. When assembling is started, the assembling robot takes out the parts from the inlet tray, places the parts in the clamp to clamp and assemble the parts, and then carries out the next assembling process. After all the assembly procedures on the assembly units are completed, the semi-finished products are moved into an outlet tray, and the semi-finished products are moved into an inlet tray of the next assembly unit by a transfer robot, so that the whole assembly process is completed sequentially.
2. According to the characteristics of the assembly line, a mathematical model of corresponding assembly line problem assumption and multiple optimization targets is provided
The main content of the section is to propose a mathematical model conforming to the characteristics of the assembly line on the basis of a balance model of a second robot assembly line according to the reconfigurable flexible assembly line. The optimization targets of the mathematical model comprise three parts, namely a production takt CT, a tool replacement time RT and a workbench cost ST. Considering that factors affecting the actual production efficiency of the assembly line are not only the production tact, but also other factors, such as that a plurality of assembly processes can be distributed in the same workstation, tool replacement time caused by different assembly tools required during assembly is not negligible, and cost of an assembly unit (workbench) caused by more than one assembly unit exists in one workstation.
The problem assumptions and mathematical models for the reconfigurable flexible assembly line are specifically described as follows:
the balance problem of the assembly line is to solve the distribution problem of each operation element on an assembly workstation, and the assembly line needs to realize better balance requirements, meets certain constraint conditions and realizes high-efficiency and low-cost operation of assembly operation. According to the previously mentioned assembly cell characteristics, in order to more appropriately describe the research problem, the following assumptions are made:
(1) All procedures are the smallest working element and are not subdivided;
(2) Each assembly process can be assigned to any workstation, but the same assembly process cannot be assigned to a plurality of different workstations;
(3) The priority relation among the working procedures is known and fixed, and is determined by the priority relation diagram, so that the assembly working procedures distributed to the working stations also strictly accord with the priority constraint relation;
(4) The working procedure time is fixed and is determined according to the actual situation;
(5) The feeding and discharging time and the starting time of the robot are ignored;
(6) The clamp replacement time and the transfer time of the transfer robot are ignored.
The typical second type of robot assembly line balancing problem is to give the number of work stations, minimize the tact, that is, minimize the maximum assembly time of all work stations, make the assembly time between each work station not much different, improve the assembly line balance. The improvement is based on the second type of robot balancing problem, and the multi-objective optimization problem comprising the production takt CT, the tool replacement time RT and the workbench cost ST is considered.
min w 1 *CT+w 2 *RT+w 3 *ST
Wherein w is 1 、w 2 、w 3 Respectively the weights of the corresponding considerations.
Mathematical model of CT:
the constraint conditions are:
wherein, CT is the production beat; i, j is the number of the assembly process, i, j=1, 2, …, n; k is the workstation number, k=1, 2, …, m; n is the total number of assembly procedures; m is the total number of workstations, namely the total number of robots; t is t i The time of the step i; pre (i) is a set of direct pre-processes for task i; decision variable x ik Is that
Mathematical model of RT:
the constraint conditions are:
wherein RT is the assembly tool change time; RTI is the time required to replace a tool once; the decision variable Tool (i, j) is
Decision variable P (i, j) is
The mathematical model of ST is:
ST＝STI·(n+S)
wherein ST is the total cost of the assembled unit; STI is the cost of one assembly unit; s is the increased number of assembled units.
3. Solving the model by utilizing a pre-optimization operator and a double population genetic algorithm to obtain an assembly line layout
And solving a mathematical model by using a pre-optimization operator and a double population genetic algorithm. The priority relation diagram of the assembly process of the product determines the priority order among the product processes, and for the process i with larger assembly time, the process i can be divided into two identical processes i 'and i', so that the assembly time is halved, and the assembly efficiency is improved. The population genetic algorithm is used as a classical heuristic method and is a random optimized search algorithm which is performed by simulating and comparing the evolutionary process of organisms.
The following is specific description of the solution using the pre-optimization operator and the double population genetic algorithm:
because of the particularity of the reconfigurable flexible assembly line, a plurality of assembly units can be arranged in one workstation, the additionally increased number of assembly units is calculated by a pre-optimization operator instead of being generated randomly, the operator can help us to split the assembly process with larger assembly time, and the assembly units with the same number of the split processes are added in the workstation, so that the assembly time of the process is reduced.
An example test of mathematical modeling and solving is performed by selecting a typical hydraulic valve product of a certain company, and a priority relation diagram obtained according to an actual assembly process is shown in fig. 2. The whole assembly process includes 12 processes in total, the numbers beside the process number indicate the process time, and the dashed boxes indicate the processes with larger process time.
Then, pre-optimization is carried out, namely, the key process with larger process time is split, namely, the process 2 and the process 9 in the previous figure have the process time of 24 and 20 respectively, and the preferential relation graph after the splitting is shown in the figure 3. As shown in the graph of the priority relationship after the disassembly, the numbers beside the dashed boxes represent the new assembly time, and the key steps 2 and 9 become steps 2', 2 "and 9', 9", respectively, and the step time becomes half of the original step time, that is, the step time of steps 2', 2 "is 12, and the step time of steps 9', 9" is 10.
Then solving by using a double population genetic algorithm. The common population algorithm is simple and easy to operate, the searching speed is high, but the searching space is limited, the dilemma of local optimization is very easy to be trapped, and the double population genetic algorithm can better solve the problem.
The main implementation process of the algorithm comprises the following steps:
(1) Encoding: the method adopts a working element sequence coding mode to code chromosomes, and the working elements are beaten into a row according to the priority relation, and each corresponds to a gene position to form an individual.
(2) Decoding: and on the premise of meeting the process priority relation, sequentially distributing the processes to the work stations.
(3) Initializing a population: a random method is used to initialize the population.
(4) Fitness function: i.e. a multi-objective optimization function.
(5) Selection, crossover and mutation operators: and selecting excellent individuals through comparison of fitness functions, and realizing the superior and inferior elimination.
Compared with the prior art, the embodiment has the following advantages:
1. the existing assembly line is generally a non-fully automated or less flexible assembly line, and the present embodiment provides a reconfigurable flexible assembly line.
2. The existing mathematical model does not conform to the characteristics of the assembly line and has limited practical application, and the embodiment provides a problem assumption and mathematical model which conform to the characteristics of the reconfigurable flexible assembly line.
3. The feasible solution obtained by the existing model solving method is not optimal enough and can still be optimized continuously, and the mathematical model is solved by the prepositive optimizing operator and the improved double-population genetic algorithm.
Finally, we tested the above method by way of example, the test results are shown below.
A double population genetic algorithm was written using matlab language, a precedence relationship graph was input, the number of assembly workstations was set to 5, and the types of tools required for each process were set, and the assembly tool table required for each process was shown in table 1.
TABLE 1
| Kinds of assembling tools | Sequence number |
| 1 | 1、4、8 |
| 2 | 3、5、9、10、11 |
| 3 | 2、6、7 |
| 4 | 12 |
The process distribution diagram obtained by solving the double population genetic algorithm is shown in figure 4. The abscissa represents the serial number of the assembly station, the ordinate represents the total time of the station, each small rectangle in the figure represents a procedure, of the two numbers in the small rectangle, the left number is the serial number of the procedure, and the right number is the assembly time of the procedure. Taking the first workstation as an example, the process 8 and the process 10 are assigned to the workstation 1, whereby the total time of the workstations 1-5 can be calculated as: 20. 15, 27, 29, 27, the tact ct=29 is calculated; similarly, the number of tool changes is 4, so rt=rti×4; the number of work stations is 5, the number of required main work stations is 5, the number of splitting processes is two, the number of required auxiliary work stations is 2, and thus the total number of required assembly units is 7, so st=sti×7.
Two indexes for measuring the balance degree of the assembly line are given: smoothing coefficient SI, balance rate P. Assembly line balance rate P: is an important index of the balance of the assembly line and the time utilization efficiency in the whole assembly process, and the larger the balance rate is, the higher the time utilization efficiency is.
The smoothing coefficient SI is a distribution condition of each workstation time relative to the production beat on the assembly line, and reflects the discrete condition of each workstation time. The smaller the smoothing factor, the smaller the deviation of all workstation times from the beat, the better the assembly line balance.
CT is a beat, and ct=max (T i )；T i The workstation time is the sum of all times of the process allocated to the workstation; m is the number of work stations
For the above test results, the obtained smoothing coefficient si= 3.376 has a balance rate of 81.4%, and the assembly line balance effect is good.
The split process (process 2 and process 9) resulting from the process map plus the pre-optimization can result in a workstation logic map, also called an assembly line logic map, as shown in fig. 5. The numbers outside the frame in fig. 5 represent the serial numbers of the work stations, the numbers in the frame represent the serial numbers of the working procedures, five work stations are shared, the solid frame is the main work station, the dotted frame represents the auxiliary work station, and the main work station and the auxiliary work station complete the same assembly working procedure, so that the working procedures in the same work station are allocated with the split working procedure, the benefit of halving the assembly time can be obtained, the assembly time of the work station is reduced, the production takt CT in the optimization target can be reduced, and better results are obtained. It is also noted that this is simply a logical layout diagram representing the logical order of assembly of each workstation and not a true physical layout diagram.
To obtain the physical layout required in actual production, the direct post-process of the process in each workstation on the priority relation diagram needs to be considered, and meanwhile, factors such as occupied area, semi-finished product transfer efficiency and the like are considered, and here, the physical layout is deduced by taking the above logic layout as an example, as shown in fig. 6.
By way of example with respect to workstation 1, the semifinished product of workstation 1 is sent to both workstation 2 and workstation 5, since in workstation 1, processes 8 and 10 are assembled, whereas the direct subsequent process to process 8 is process 9, which is carried out in workstation 2, and the direct subsequent process to process 10 is process 11, which is carried out in workstation 5.
The background section of the present invention may contain background information about the problems or environments of the present invention and is not necessarily descriptive of the prior art. Accordingly, inclusion in the background section is not an admission of prior art by the applicant.
The foregoing is a further detailed description of the invention in connection with the preferred embodiments, and it is not intended that the invention be limited to the specific embodiments described. It will be apparent to those skilled in the art that several equivalent substitutions and obvious modifications can be made without departing from the spirit of the invention, and the same should be considered to be within the scope of the invention.
Claims (7)
1. A method of reconfigurable flexible assembly line layout, comprising the steps of:
s1, designing a reconfigurable flexible assembly line taking a reconfigurable flexible assembly unit as a core component part;
s2, a corresponding problem assumption and a mathematical model with multiple optimization targets are proposed according to the reconfigurable flexible assembly line;
s3, solving the mathematical model by utilizing a prepositive optimization operator and a double population genetic algorithm to obtain a reconfigurable flexible assembly line layout;
wherein the problem assumption includes:
s2-1, all working procedures are minimum operation elements and are not subdivided;
s2-2, each assembly process can be distributed to any work station, but the same assembly process cannot be distributed to a plurality of different work stations;
s2-3, the priority relation among the working procedures is known and fixed and is determined by a priority relation diagram, so that the assembly working procedures distributed to the working stations also strictly accord with the priority constraint relation;
s2-4, the working procedure time is fixed and is determined according to actual conditions;
s2-5, neglecting loading and unloading time and starting time of a robot;
s2-6, the clamp replacement time and the transfer time of the transfer robot are ignored;
the optimization targets of the mathematical model comprise production takt CT, tool replacement time RT and workbench cost ST;
min w 1 *CT+w 2 *RT+w 3 *ST
wherein w is 1 、w 2 、w 3 Weights of corresponding consideration factors respectively;
the mathematical model of the takt time CT is as follows:
the constraint conditions are:
wherein, CT is the production beat; i, j is the number of the assembly process, i, j=1, 2, n; k is the serial number of the workstation and, k=1, 2,. -%, m; n is the total number of assembly procedures; m is the total number of workstations, namely the total number of robots; t is t i The time of the step i; pre (i) is a set of direct pre-processes for task i; decision variable x ik Is that
The mathematical model of the tool change time RT is:
the constraint conditions are:
wherein RT is the assembly tool change time; RTI is the time required to replace a tool once; the decision variable Tool (i, j) is
Decision variable P (i, j) is
The mathematical model of the table cost ST is:
ST＝STI·(n+S)
wherein ST is the total cost of the reconfigurable flexible assembly unit; STI is the cost of one of the reconfigurable flexible assembly units; s is the increased number of said reconfigurable flexible assembly units.
2. The method according to claim 1, wherein in step S1, the reconfigurable flexible assembly unit comprises a robot (101), an assembly tool and tool holder (102), an assembly jig and jig base (103), a tray (104); the robot (101) is located in the center of the workbench, and the assembling tool and tool rack (102), the assembling clamp and clamp base (103) and the tray (104) are in annular layout on the workbench.
3. A reconfigurable flexible assembly line layout method according to claim 2, wherein the robot (101) is adapted to perform assembly actions on the reconfigurable flexible assembly unit;
in the assembling tool and tool rack (102), the assembling tool is stored on the tool rack, and the assembling tool can be arranged at the tail end of the robot (101) and is used for assembling parts;
in the assembly fixture and the fixture base (103), the assembly fixture is arranged on the fixture base and is used for fixing and positioning parts;
the assembly tool and the assembly fixture are matched with an assembly task to be completed on the reconfigurable flexible assembly unit;
the tray (104) is used for containing parts required for assembly and conveyed by a peripheral material conveying system.
4. A method of reconfigurable flexible assembly line layout according to claim 3, wherein the operation of the reconfigurable flexible assembly line includes: before assembly begins, the number of the reconfigurable flexible assembly units is determined, the required assembly tools and the required assembly jigs are determined according to the assembly process of products, then an AGV trolley conveys the required assembly tools and the required assembly jigs to the reconfigurable flexible assembly units from an assembly tool library and an assembly jig library respectively and are arranged on the tool rack and the jig base respectively, and parts are placed in the tray (104) on a workbench by a material conveying system; when assembling is started, the robot (101) takes out the parts from the inlet tray, places the parts in a clamp to clamp and assemble, and then carries out the next assembling process; after all the assembly procedures on the reconfigurable flexible assembly unit are completed, the semi-finished product is moved to an outlet tray, and the semi-finished product is moved to an inlet tray of the next reconfigurable flexible assembly unit by a transfer robot, so that the whole assembly process is sequentially completed.
5. The method according to claim 1, wherein the pre-optimization operator in step S3 "splits" the assembly process with a larger assembly time, and adds the same number of assembly units as the split process in the workstation, so as to reduce the assembly time of the process, thereby calculating the number of the reconfigurable flexible assembly units that can be additionally added in one workstation.
6. The method of claim 1, wherein the step S3 is mainly implemented by a double population genetic algorithm, and the method comprises:
s3-1, coding: the method comprises the steps of encoding a chromosome by adopting an operation element sequence encoding mode, and photographing operation elements into a row according to a priority relation, wherein each operation element corresponds to a gene position to form an individual;
s3-2, decoding: on the premise of meeting the process priority relation, sequentially distributing the processes to the workstations;
s3-3, initializing a population: initializing a population by adopting a random method;
s3-4, fitness function: namely a multi-objective optimization function;
s3-5, selecting, crossing and mutating operators: and selecting excellent individuals through comparison of fitness functions, and realizing the superior and inferior elimination.
7. A reconfigurable flexible assembly line layout device characterized in that a reconfigurable flexible assembly line layout is obtained using the method of any of claims 1-6.
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