Device for controlling the parameters of a manufacturing process

• US 5,631,839 A
• Filed: 06/19/1995
• Issued: 05/20/1997
• Est. Priority Date: 07/18/1994
• Status: Expired due to Fees

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Lemoine, Michel
• Primary Examiner(s): RUGGIERO, JOSEPH F
• Application Number:
  US08/492,360
• Time in Patent Office: 701 Days
• Field of Search: 364/468, 364/138, 364/139, 364/550, 364/551.01, 364/468.01, 364/968.02, 364/468.15, 364/468.16, 364/468.17, 364/131-136, 340/825.06, 340/825.07
• US Class Current: 700/108
• CPC Class Codes: G05B 19/41875 characterised by quality surveillance of production
• CPC Class Codes: G05B 2219/31151 Lan local area network
• CPC Class Codes: G05B 2219/32182 If state of tool, product deviates from standard, adjust system, feedback
• CPC Class Codes: G05B 2219/32407 Real time processing of data
• CPC Class Codes: G05B 2219/33268 D-A, A-D
• CPC Class Codes: G05B 2219/34048 Fourier transformation, analysis, fft
• CPC Class Codes: G05B 2219/37494 Intelligent sensor, data handling incorporated in sensor
• CPC Class Codes: G05B 2219/37597 Spectrum analyser
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

The invention concerns a device for controlling a complex manufacturing process. The device comprises at least one remote monitor designed to receive in real time signals through a local area network making it possible to analyse the state of the manufacturing process. There are a plurality of sensors, each of the sensors transforming the value of an associated parameter of the manufacturing process so as to produce an analogue signal. There is an analogue to digital converter associated with each of the sensors for producing a succession of numerical values representing the instantaneous state over time of the corresponding parameter. Each of the converters is interfaced with the local area network. A processor for processing the numerical values and comparing them with given reference values is also connected to the local area network such that the local area network conveys the result of the comparison to the remote monitor or monitors and also conveys the information coming from the analogue to digital converter to the processing means.

Claims

1. Device for continuously controlling a manufacturing process, in order to perceive continuously any transient or perturbational phenomena occurring during this process, a device comprising:

a) a local area network;

b) at least one remote monitor connected to said local area network through a first interface for receiving, in real time, signals in order to control the manufacturing process;

c) a plurality of sensors, each of said sensors measuring a value of one of a plurality of parameters of the manufacturing process and transforming said value so as to produce an analogue signal;

d) a plurality of analogue to digital converters, each of said analogue to digital converters connected to one of said sensors and located proximate thereto, each of said analogue to digital converters receiving one of said analogue signals in order to convert said one of said analogue signals into a sequence of numerical values representing an instantaneous state over time of the corresponding parameter, each of said analogue to digital converters being connected to said local area network through a second interface;

e) processing means connected through a third interface to said local area network for storing and processing said sequences of numerical values and comparing said sequences of numerical values with predetermined reference values in order to generate a plurality of comparison signals, said local area network conveying said comparison signals to said remote monitor and from said analogue to digital converters to said processing means.

2. Device according to claim 1, characterised in that said processing means are arranged so as to receive, process and store the values coming from a plurality of sensors via their respective analogue to digital converters.

3. Device according to claim 1, further comprising a plurality of second processing means, each of said second processing means being associated with one of said sensors.

4. Device according to claim 1, characterised in that said processing means comprise:

i) means for transforming said sequences of numerical values into frequency variation signals representing frequency variations of said analogue signals and then, after generating said frequency variation signals, storing said frequency variation signals;

ii) an analyser receiving said frequency variation signals in order to convert said frequency variation signals into a limited number of objective characteristics; and

iii) storage means for storing the said limited number of objective characteristics.

5. Device according to claim 4, characterised in that the means for transforming said sequences of numerical values into frequency variation signals effects a discrete Fourier transform.

6. Device according to claim 5, further comprising:

i) a plurality of actuators for implementing the process, each of said actuators being controlled by one of a plurality of control signals, each of said control signals influencing the value of at least one corresponding parameter of the process, said processing means also producing with said comparison signals a plurality of digital correction signals for modifying said control signals addressed to said actuators; and

ii) a digital to analogue converter associated with each of said actuators for converting said digital correction signals into a plurality of corresponding analogue correction signals, each of said analogue correction signals being addressed to a corresponding one of said actuators said processing means being connected to said digital to analogue converters by means of said local area network.

7. Device according to claim 5, further comprising:

i) a plurality of actuators for implementing the process, each of said actuators being controlled by an analogue control signal which influences the value of at least one corresponding parameter of the process, said processing means producing, as a result of comparing said sequences of numerical values with the predetermined values, a plurality of digital correction signals, each of said digital correction signals for modifying one of said control signals addressed to one of said actuators; and

ii) a pulse-width modulation device associated with each of said actuators for converting said digital correction signals into a plurality of corresponding variable pulse width signals, each of said pulse-width modulation devices modifying accordingly the value of the associated parameter or parameters, said processing means being connected to each of said pulse-width modulation devices by means of said local area network.

8. Device for continuously controlling a manufacturing process, in order to perceive continuously any transient or perturbational phenomena occurring during this process, a device comprising:

a) a local area network;

b) at least one remote monitor connected to said local area network through a first interface for receiving in real time signals in order to control the state of the manufacturing process;

c) a plurality of sensors, each of said sensors being associated with one of a plurality of parameters of the manufacturing process and measuring a value of said one of said plurality of parameters and transforming said value so as to produce an analogue signal;

d) a plurality of analogue to digital converters, each of said analogue to digital converters being connected to one of said sensors and situated proximate thereto and receiving said analogue signal in order to convert said analogue signal into a sequence of numerical values representing an instantaneous state over time of said plurality of parameters, each of said analogue to digital converters being connected to the local area network through one of a plurality of second interfaces;

e) a plurality of actuators, each of said actuators acting on a device for modifying at least one of the parameters;

f) a digital to analogue converter associated with each of said actuators, each of said digital to analogue converters being connected to said local area network through one of a plurality of third interfaces;

g) processing means connected through a fourth interface to said local area network for storing and processing said sequences of numerical values and comparing said sequences of numerical values with predetermined reference values in order to generate a comparison signal, said local area network conveying said sequences of numerical values from said analogue to digital converters to said processing means and said comparison signal to said remote monitor or monitors.