JPH04315533A - Fms process control device - Google Patents

Abstract

PURPOSE:To decide a highest priority part feeding station and to increase the efficiency of a production line by grasping the charge float of each station at a real time, in a flow shop type FMS line. CONSTITUTION:An assembly remaining time of each assembly station is calculated, based on a predetermined assembly time of each of assembly stations C2-Cn and a time between the starting of assembly of each assembly station and a present time. The charge float of each part feeding station is calculated, based on the calculating assembly remaining time and a present quantity of parts of each of part feeding stations S1-Sn. A highest priority part charge station is decided, based on the charge float and a maximum quantity of loaded parts of each part feeding station.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible manufacturing system (hereinafter abbreviated as FMS), and particularly to a process control method thereof.

0002

BACKGROUND OF THE INVENTION Under the circumstances of rising material prices and labor costs, and a shift from mass production to high-mix, low-volume production, there is a need for a production system that can achieve higher efficiency with limited equipment. In conventional FMS lines, parts are introduced into each station according to a predetermined plan, or
Alternatively, process control is performed using a station-individual management system in which an input request is made when an arbitrary station reduces the input amount to the required input amount.

0003

[Problems to be solved by the invention] In the conventional method, process changes due to line fluctuations cannot be made in real time, and control is performed focusing only on arbitrary stations, so it is difficult to determine the highest priority loading station. The problem is that it cannot be done. Therefore, the problem to be solved by the present invention is to calculate the input margin time of each component supply station in an FMS process control device, determine the highest priority component input station, and enable optimal process control.

0004

[Means for Solving the Problem] In order to solve this problem, the FMS process control device of the present invention provides a plurality of component supply stations S1 to S having a predetermined buffer capacity.
n, a plurality of assembly stations C2 to Cn that assemble those parts, and one or more transport devices M that transport parts from the previous process and input them to the parts supply stations S1 to Sn. In a process control device for a flow shop type FMS line, a predetermined assembly time t for each of the assembly stations C2 to Cn
calculation means for calculating the remaining assembly time tmrem for each assembly station based on m and the time trm from the start of assembly to the present for each assembly station; and the calculated remaining assembly time tmrem for each assembly station and the parts supply. a calculation means for calculating the input margin time Tm for each component supply station based on the current component quantity Nm for each station; The present invention is characterized by comprising calculation means for determining the highest priority parts input station in real time based on the transfer quantity max (Nm).

[0005]

[Operation] By the above means, the supply time margin of each station is grasped in real time, and the highest priority parts supply station is determined. This makes the production line more efficient.

[0006]

Embodiments Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an equipment configuration diagram of a flow shop type FMS. This equipment consists of a transport device M, a plurality of component supply stations S1 to Sn, and a plurality of assembly stations C2 to Cn. The transport device M transfers the parts from the previous process and supplies the parts to any part supply station from S1 to Sn. The component supply stations have a mechanically predetermined buffer capacity for each station. The parts at the parts supply station are assembled together with the intermediate products assembled from the upstream station at the assembly station, and flow to the downstream station. After flowing to the downstream station, assembly of intermediate products from the upstream station and parts within the own station is started repeatedly.

The method of determining the highest priority parts input station shown in FIG. 2 will be explained. First, the parameters required for processing are explained below. Sm: Name of parts supply station (m≧1) Cm:
Assembly station name (m≧2) tm: Assembly time for each assembly station trm: Time from the start of assembly to the present for each assembly station tmrem: Remaining assembly time for each assembly station Nm
: Current parts quantity Tm for each parts supply station : Maximum loading margin time for each parts supply station (Nm) : Maximum transferable quantity of parts for each parts supply station min (Tm) : Maximum loading margin time with the least loading margin (Tm): Maximum loading margin time for each parts supply station at max (Nm)

Next, the processing in each processing section will be explained. The calculation processing unit 13 calculates the remaining assembly time for each assembly station based on the assembly time tm storage unit 11 for each assembly station and the current assembly time trm storage unit 12 for each assembly station. The remaining assembly time tmrem for each time is tmrem=t
It is calculated by calculating m-trm and stored in the storage unit 14. Here, when tm<trm, that is, when the scheduled assembly time is exceeded, or when waiting for an intermediate product from an upstream station, a negative value is taken. The processing unit 16 determines the input margin time Tm for each component supply station based on the remaining assembly time tmrem for each assembly station stored in the storage unit 14 and the current parts quantity Nm for each component supply station stored in the storage 15. Tm=N
m ×tm +tmrem (however, Nm ≠0, tm
When rem≦0, tmrem=0). This value is stored in the storage section 17. Here Nm
When ≠0 and tmrem≦0, that is, there are parts at the parts supply station, and the assembly time is extended or an intermediate product is waiting from an upstream station, the remaining assembly time (negative value) is included in the input margin time. do not have. The processing unit 19 calculates the loading time Tm for each component supply station stored in the storage unit 17 and the maximum transferable number of parts max (Nm) for each component supply station stored in the storage unit 18. , determines the highest priority parts input station. Specifically, this is performed according to the flowchart shown in FIG.

Step 191: Check whether Tm≧max(Tm) for all stations. That is, it is checked whether all parts supply stations are full. Step 192: When at least one component supply station is not fully loaded, Tm
Extract parts supply stations that satisfy ≦0. That is, stations whose assembly has been completed while the component supply station is empty are sequentially searched and extracted from upstream stations. Step 193: Select the component supply station Sm closest to the upstream that satisfies Tm≦0. Step 194: If there is no component supply station that satisfies Tm≦0, Tm with the shortest input margin time
=min(Tm) is extracted from the upstream station and selected as the component supply station Sm. Step 195: Since all parts supply stations are full, parts cannot be supplied, and instructions to input them into the transport device are prohibited. Step 196: Step 193 or Step 194
The component supply station Sm selected in is set as the highest priority component input station, and an instruction is given to the component supply station Sm to be input to the transport device.

0010

[Effects of the Invention] As described above, in a flow shop type FMS line, by calculating and understanding the input margin time of each station, the input margin time at each component input station is T1 ≒T2 ≒T3 ≒...
・≒Tm, which has the remarkable effect of achieving stable and highly efficient productivity.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an example of equipment for a flow shop type FMS line.

FIG. 2 is a functional block diagram showing a specific embodiment of the present invention.

FIG. 3 is a flowchart illustrating processing for determining the highest priority parts input station.

[Explanation of symbols]

1 Transport device, 2 Parts supply station, 3
Assembly station 11 Assembly time storage section 12 for each assembly station
Current assembly time storage section 13 for each assembly station Calculation processing section 14 for calculating remaining assembly time for each assembly station Remaining assembly time storage section 15 for each assembly station
Current parts quantity storage section 16 for each parts supply station
Calculation processing unit 17 for calculation of margin loading time for each component supply station; margin loading time storage unit 18 for each component supply station; storage unit for the maximum transferable number of parts for each component supply station;

Claims (1)

[Claims] Claim 1: A plurality of component supply stations S1 to Sn having a predetermined buffer capacity and a plurality of assembly stations C2 to Cn for assembling those components.
and one or more transport devices M for transporting parts from the previous process and inputting them to the component supply stations S1 to Sn, in which the assembly stations C2 to Sn are configured.
Predetermined assembly time tm for each Cn and time trm from the start of assembly to the present for each of these assembly stations
Remaining assembly time tmr for each assembly station based on
a calculation means for calculating em, and a calculation means for calculating an input margin time Tm for each component supply station based on the calculated remaining assembly time tmrem for each assembly station and the current number of parts Nm for each component supply station. , calculation means for determining the highest priority component input station in real time based on the calculated input margin time Tm for each component supply station and the maximum number of parts transferred max (Nm) for each component supply station. An FMS process control device characterized by: