阅读说明：本技术 用于为给电路板装配电子构件的装配线确定装备族的方法 (Method for determining equipment family for assembly line of electronic components for circuit board ) 是由 A·普法芬格 C·罗瓦耶 于 2019-03-25 设计创作，主要内容包括：本发明要求保护一种用于为给电路板(120)装配一种或多种构件类型的电子构件(155)的装配线(110)确定装备族(250、255)的方法,其中所述方法包括如下步骤：检测预先给定或可预先给定数目的装备族(250、255)；其中装备族被确定为电路板的集合,所述电路板能够在装配线上被装配,而不改变在所述装配线处准备好装配的构件类型的集合；其特征在于,借助于整数线性规划来优化所要分发的电路板到所检测到数目的装备族上的分配,使得每个装备族的构件类型的数目之和被最小化；而且以被分配给所述电路板的装备族来执行对所述电路板的装配。(The invention claims a method for determining a family of equipment (250, 255) for an assembly line (110) for assembling electronic components (155) of one or more component types to a circuit board (120), wherein the method comprises the steps of: detecting a predetermined or a predetermined number of equipment groups (250, 255); wherein an equipment family is determined as a set of circuit boards that can be assembled on an assembly line without changing a set of component types ready for assembly at the assembly line; characterized in that the allocation of the circuit boards to be distributed to the detected number of equipment families is optimized by means of an integer linear program such that the sum of the number of component types of each equipment family is minimized; and the assembly of the circuit board is performed in the equipment family assigned to the circuit board.)

1. A method for determining a family of equipment (250, 255) for an assembly line (110) for assembling electronic components (155) of one or more component types to a circuit board (120), wherein the method comprises the steps of:

-detecting a predefined or predefined number of equipment families (250, 255),

-wherein an equipment family is determined as a set of circuit boards that can be assembled on an assembly line without changing the set of component types ready for assembly at the assembly line,

it is characterized in that the preparation method is characterized in that,

optimizing the allocation of the circuit boards to be distributed to the detected number of equipment families by means of integer linear programming such that the sum of the number of component types per equipment family is minimized, and

-performing the assembly of the circuit board in a family of equipments assigned to the circuit board.

2. Method according to the previous claim, characterized in that the detected number of families of equipment represents the minimum number of families of equipment.

3. Method according to one of the preceding claims, characterized in that a maximum threshold value in the form of a maximum degree of filling is predefined for the set of component types that are ready for assembly at the assembly line.

4. The method of any preceding claim, wherein the circuit boards to be distributed are also distributed over the detected number of equipment families such that the circuit boards are distributed to a first subset of circuit boards to be distributed of the same equipment family.

5. The method according to claim 4, characterized in that the circuit boards to be distributed are also distributed over the detected number of equipment families such that the circuit boards are distributed to a second subset of the circuit boards to be distributed of the respectively other equipment family.

6. A control device for determining a family of equipment (250, 255) for an assembly line (110) for assembling electronic components (155) of one or more component types to a circuit board (120), the control device having:

-means for detecting a predefined or predefined number of equipment families (250, 255),

-wherein an equipment family is determined as a set of circuit boards that can be assembled on an assembly line without changing the set of component types ready for assembly at the assembly line,

it is characterized in that

-means for allocating the circuit boards to be distributed onto the detected number of equipment families designed to optimize the allocation by means of an integer linear programming such that the sum of the number of component types of each equipment family is minimized, and

-means for performing the assembly of the circuit board with the family of equipment assigned to the circuit board.

7. A computer program product having program code means for performing the method according to any one of the preceding method claims when the computer program product is run on a control device according to any one of the preceding control device claims or stored on a computer readable medium.

Technical Field

The invention relates to a method for determining a family of equipment for an assembly line for assembling electronic components or devices to a circuit board. The invention also relates to a control device for a production or assembly line for assembling components to circuit boards. The invention also relates to a computer program product and a computer readable medium.

Background

In the field of electronics production, in particular, circuit boards or components to be produced are produced by Surface Mounted Technology (SMT) in an SMT assembly line.

An equipment family is defined as a collection of circuit boards or components that can be assembled on an assembly line without changing the type of components or the collection of device types that are ready for assembly on the assembly line. Existing tools for determining equipment families often either require manual expense or provide results that are not always convincing. Other known tools are tied to a particular assembly system for use.

Disclosure of Invention

The invention aims to provide the following steps: an improved technique for distributing or distributing circuit boards over a predefined or predefinable number of equipment families having a minimum number of component types to be equipped is provided.

The minimum number of component types to be equipped on the exchange stations that provide the means for manufacturing the circuit boards on the production line saves time and economic costs. The collection of device types prepared at the assembly line is also referred to as equipment. It is generally assumed that: a sufficient number of components are always ready at the assembly line.

This object is achieved by the independent claims. Advantageous embodiments are the subject matter of the dependent claims.

The invention claims a method for determining a family of equipment for an assembly line for assembling electronic components of one or more component types to a circuit board, wherein the method comprises the following steps:

detecting a predetermined or a predetermined number of equipment families,

-wherein an equipment family is determined as a set of circuit boards that can be assembled on an assembly line without changing the set of component types ready for assembly at the assembly line,

it is characterized in that the preparation method is characterized in that,

-optimizing the distribution of the circuit boards to be distributed onto the detected number of equipment families by means of integer linear programming such that the sum of the number of component types per equipment family is minimized.

In the case of the obtained assignment, the assembly of the circuit boards can be performed with the family of equipment assigned to these circuit boards.

Less installation space is therefore required, since redundant installation of components of the same component type is generally avoided.

The detected number of equipment families may represent a minimum number of equipment families.

One embodiment of the invention provides for: a maximum threshold value in the form of a maximum degree of filling is predefined for the set of component types that are ready for assembly at the assembly line.

One embodiment of the invention provides for: the circuit boards to be distributed are also distributed over the detected number of equipment families such that they are distributed to a subset of the circuit boards to be distributed of the same equipment family.

One embodiment of the invention provides for: the circuit boards to be distributed are also allocated to the detected number of equipment families, so that these circuit boards are allocated to a subset of the circuit boards to be distributed of the respectively other equipment family.

With this method, good results can be achieved in a relatively short time for small scale problems, such as for a fixture wire. The method is also very flexible, that is to say additional constraints and other low-weight objective function components can be easily embedded. With reduced capital equipment, time and economic savings are achieved. This method can be used in all the usual assembly line cases.

A further aspect of the invention provides a control device which is designed in particular for carrying out a method of the type mentioned above and the embodiments thereof. The control device can be a computer which is attached to the installation system and can be arranged separately or a control module which is integrated into the installation system.

A control device for determining a family of equipment for an assembly line for assembling electronic components of one or more component types to a circuit board has:

-means for detecting a predetermined or a predetermined number of equipment families,

-wherein an equipment family is determined as a set of circuit boards that can be assembled on an assembly line without changing the set of component types ready for assembly at the assembly line,

it is characterized in that

-means for allocating the circuit boards to be distributed onto a detected number of equipment families designed to optimize the allocation by means of an integer linear programming such that the sum of the number of component types of each equipment family is minimized, and

-means for performing assembly of the circuit boards with the family of equipment assigned to them.

Another aspect of the invention is a computer program (product) with program code means for performing the method according to any one of the preceding method claims, when said computer program (product) is run on a control device of the above-mentioned type or stored on a computer readable medium.

The computer program or the computer program product may be stored on a computer readable medium. The computer program or the computer program product may be created in a common programming language (e.g. C + +, Java). The processing means may comprise a commercially available computer or server having corresponding input means, output means and storage means. The processing means may be integrated in the control device or in a device of the control device.

The control device and the computer program (product) may be extended or constructed similarly to the above-mentioned method.

Further advantages, details and embodiments of the invention result from the following description of an embodiment with reference to the drawings.

Drawings

FIG. 1 shows an assembly system;

fig. 2 shows a diagram relating to the formation of an equipment family at the assembly system of fig. 1 according to the invention.

Detailed Description

One possible optimization method for optimizing the assignment to the circuit boards to be distributed is linear optimization. The linear optimization aims at optimizing a linear objective function over a set limited by linear equations and inequalities. This linear optimization is the basis of the solution method of (mixed) integer linear optimization. The so-called solvers are a collective term for special mathematical computer programs that can numerically solve mathematical problems. In connection with MILP (mixed integer linear programming or mixed integer linear programming), standard solvers such as CPLEX, Scip, Gurobi, Xpress can be used for IP programs (integer optimization models).

Fig. 1 shows an assembly system 100. The mounting system 100 includes: a plurality of assembly lines 110; and a control device 115 for distributing the circuit boards 120 to the assembly line 110. Each assembly line 110 typically includes a transport system 125 and one or more assembly robots 130. Each assembly robot 130 comprises one or more assembly heads 135, which are each set up to pick up components from the constant table 140 or the variable table 145 and to place these components at predetermined positions on the circuit board 120, which is located on the transport system 125.

During the assembly process, the circuit board 120 is generally stationary relative to the assembly robot 130. The work stations 140, 145 each comprise a plurality of transport devices 150, of which only one is shown by way of example. Each conveyor 150 is prepared with an inventory of devices 155 of a predetermined type. Although each transport device 150 can be configured for preparing different components or devices 155 and different transport devices 150 can be installed at the work stations 140, 145, the work stations 140, 145 are usually completely exchanged for speed reasons if the assembly robot 130 has to be supplied with components 155 which are not provided on one of the installed work stations 140, 145.

Since such replacement usually brings about production stoppages, it is sought to keep the number of tables 140, 145 to be replaced low. The table is referred to as a constant table 140 if it is not replaced during the retrofitting process, and a variable table 145 otherwise. In other cases, there is no functional distinction between the constant stage 140 and the variable stage 145.

The circuit board 120 is to be equipped with a number of different components 155. In order to minimize frequent replacement of the variable tables 145 and ideally maximize the number of constant tables 140, the control device 115 is set up to: the assignment of the circuit board 120 to one of the assembly lines 110 is optimized. In this case, the specific properties of each assembly line 110 or each assembly robot 130 must generally be taken into account as well as the properties of the circuit board 120 or the component 155 to be mounted thereon.

FIG. 2 shows a diagram 200 of a family of equipment, also referred to as a "Cluster". A first circuit board 205, a second circuit board 210 and a third circuit board 215 are observed, which correspond to one of the circuit boards 120 in the mounting system 100 in fig. 1, respectively. A first set 220 of components 155 is to be mounted on the first circuit board 205, a second set 225 of components 155 is to be mounted on the second circuit board 210 and a third set 230 of components 155 is to be mounted on the third circuit board 215. Illustratively, sets 220, 225, and 230 each include different component or device types that are characterized in different forms and use different numbers of components 155 of the different component or device types, respectively. Thus, the sets 220-230 of components 155 are assigned sets 235-245 of component types. In the sets 235 to 245, each of the different components 155 of the corresponding sets 220 to 230 is only discovered once again.

The family of equipment includes those circuit boards 120 that are assigned for assembly on the assembly line 100. In the example of fig. 2, the circuit boards 210 and 215 are assigned to the same assembly line 110 and form a first equipment family 250. Thus, the first equipment family 250 requires a first equipment 265 having the component type assigned to the circuit boards 210 and 215. In the example shown, the first equipment 265 includes five component types. In the case of providing component types of the first equipment 265, the circuit boards 210 and 215 of the first equipment family 250 can be assembled on the assembly line 110 without retrofitting, assuming that a maximum of five different component types are accommodated in one set of equipment.

The third circuit board 205 alone forms a second equipment family 255. The second equipment 260 assigned to the second equipment family 255 includes one component type.

The sum of the component types in both installations is minimal.

The method according to the invention makes full use of the freedom in the case of individual distribution of the circuit boards to a detected predetermined/predeterminable or previously calculated or determined number of equipment families. The objective function is calculated by means of integer linear programming. The sum of the number of component types for each equipment family is minimized using the objective function. If the example in fig. 2 is considered, the second circuit board 210 is thus not assigned to the same family of equipment as the circuit board 205, but to the same family of equipment as the circuit board 215. Thus, set 235 has one device type, and set 240 has five device types in conjunction with set 245. In this case, the sum of the number of component types (one plus five) for each equipment family is six instead of ten (acanthopanax five) when the second circuit board 210 would be assigned to the same equipment family as the circuit board 205. Less installation space is therefore required, since redundant installation of components of the same component type is generally avoided.

With the method according to the invention, additional constraints can be taken into account:

there are device-table constraints on the assembly line, that is to say that devices are not allowed to be equipped on all tables, but only on a subset of the tables 140, 145.

The maximum filling degree of the conveying device can be observed.

The circuit boards of the first subset of circuit boards to be given must be distributed into the same cluster (e.g. the upper and lower side of the circuit board).

The circuit boards of the second subset of these circuit boards are not allowed to be assigned to the same cluster but have to be assigned to another cluster, respectively.

Mathematics background

By using accurate mathematical methods, a significantly better solution can be achieved than with the heuristics used so far in practice.

The following nomenclature applies in the subsequently described MILP expression:

Index

set of R circuit boards 120

Set of C device types 155

F a set of a predetermined number of equipment groups 250, 255

R_CA collection of circuit boards having device type c.

A method for forming a family of equipment on an assembly line is known from EP 2829166B 1. Therein, a method is described with which, given an assembly line and a set of circuit boards, a set with the smallest number of equipment families can be determined and thus predefined for F above. However, other methods or manual inputs are also conceivable, which can be specified for this minimum number. In addition, any other number may also be specified.

Parameter(s)

CapUsage _c Tracking usage of device c

Cap _f Number of available trajectories in equipment of equipment family f

Binary variable

x _r.f Allocation of circuit boards r to equipment families f

y _c,f Use of devices c in equipment family f

IP expression

Minimization。

With the additional conditions:

(1) each circuit board type must be assigned to exactly one equipment family:

(2) if a circuit board is assigned to a family of equipment, all device types of that circuit board must also be equipped in the equipment of the family of equipment:

(3) all device types of circuit boards of the equipment family must be matched to their tracking usage into the equipment:

(4) variable limiting conditions:

。

although the invention has been further illustrated and described in detail by means of preferred embodiments, the invention is not limited to the examples disclosed, but other variants can be derived therefrom by those skilled in the art without departing from the scope of protection of the invention.

Implementations of the processes or method flows described above may be implemented in terms of commands residing on a computer readable storage medium or in volatile computer memory (hereinafter generally referred to as computer readable memory). The computer-readable memory is, for example: volatile memory, such as cache, buffer, or RAM; and non-volatile memory such as removable disks, hard disks, and the like.

Here, the functions or steps described above may exist on/in the computer readable memory in the form of at least one command statement. Here, these functions or steps are not bound to a certain command statement or to a certain form of command statement or to a certain storage medium or to a certain memory or to a certain embodiment, and may be implemented by software, firmware, microcode, hardware, processors, integrated circuits, etc., operating alone or in any combination. Various processing strategies may be used, such as serial processing by a single processor, or multiprocessing or multitasking or parallel processing, and the like.

The commands may be stored in local memory, but it is also possible to store the commands on a remote system and access the remote system via a network.

In connection with the present invention, "computer-assisted" may be understood, for example, to mean the implementation of the method, wherein, in particular, a processor carries out at least one method step of the method. The control device may have such a processor.

The terms "processor", "central signal processing device", "control unit" or "data analysis device" as used herein include processing devices in a broad sense, i.e., for example, servers, general purpose processors, graphics processors, digital signal processors, Application Specific Integrated Circuits (ASICs), programmable logic circuits (e.g., FPGAs), discrete analog or digital circuits, and any combinations thereof, including all other processing devices known to those skilled in the art or developed in the future. Here, the processor may be composed of one or more devices or means or units. If a processor is made up of multiple devices, the devices may be designed or configured to process or implement commands in parallel or in series. In connection with the present invention, a "Memory unit" may be understood as, for example, a Memory in the form of a working Memory (RAM) or a hard disk.