Machining unit application control apparatus and method employing data from several different operations

• US 5,267,141 A
• Filed: 08/06/1990
• Issued: 11/30/1993
• Est. Priority Date: 10/07/1988
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Maruyama, Hisaichi, Nanasawa, Yoshifumi, Morita, Atsushi, Noda, Akio, Imai, Yoshihito
• Primary Examiner(s): Smith, Jerry
• Assistant Examiner(s): Trammell, Jim
• Application Number:
  US07/476,427
• Time in Patent Office: 1,212 Days
• Field of Search: 364/513, 364/130-194, 364/474.01-474.34, 395/50-77, 395/900-904, 219/69.16, 219/69.13
• US Class Current: 700/32
• CPC Class Codes: B23H 7/20 for programme-control, e.g. adaptive programme-control systems in general G05B19/00
• CPC Class Codes: G05B 19/4163 Adaptive control of feed or cutting velocity without NC B23Q15/12
• CPC Class Codes: G05B 2219/33002 Artificial intelligence AI, expert, knowledge, rule based system KBS
• CPC Class Codes: G05B 2219/45221 Edm, electrical discharge machining, electroerosion, ecm, chemical
• CPC Class Codes: Y10S 706/90 Fuzzy logic
• CPC Class Codes: Y10S 706/904 Manufacturing or machine, e.g. agricultural machinery, machine tool

Abstract

In an application control apparatus or method for a machining unit such as an electric discharge machine, a plurality of methods of realizing desirable machining states such as those on machining know how techniques are independently described and stored as knowledge, and control is carried out according to the methods thus stored, whereby the machining unit is maintained in desirable state at all times.

Claims

1. An application control apparatus for a machining unit in which machining conditions can be changed during machining, comprising:

a knowledge memory section for storing a plurality of different methods of changing machining states;

a status memory section for storing information representing at least one of present machining states, past machining states and machining conditions; and

an inference section for combining a plurality of results obtained by said plurality of different methods, respectively, in accordance with the information stored in said status memory section, thereby providing optimal machining states, each of the stored plurality of different methods for changing machining states using information stored in said status memory section that is not used by any other method to change the same machining state;

said machining conditions of said machining unit being changed in accordance with the optimal machining states.

2. The application control apparatus as defined in claim 1, wherein said inference section includes means for averaging the plurality of results obtained by said plurality of different methods to provide the optimal machining states.

3. An application control apparatus for a machining unit in which machining conditions can be changed during machining, comprising:

a knowledge memory section for storing a plurality of different methods of changing machining states in a rule format including a front condition part which describes a condition to be determined and a rear condition part describing contents to be carried out when said front condition part is satisfied and when said front condition part is not satisfied;

a status memory section for storing information representing at least one of present machining states, past machining states and machining conditions; and

an inference section for combining a plurality of results obtained by said plurality of different methods, respectively, in accordance with the information stored in said status memory section, thereby providing optimal machining states, each of the stored plurality of different methods for changing machining states using information stored in said status memory section that is not used by any other method to change the same machining state;

said machining conditions of said machining unit being changed in accordance with said optimal machining states.

4. The application control apparatus as defined in claim 3, wherein said inference section includes means for averaging the plurality of results obtained by said plurality of different methods to provide the optimal machining states.

5. An application control apparatus for a machining unit, comprising:

a jump controlling unit for controlling a jumping operation of a machining electrode in a discharge machining operation;

a knowledge memory section for storing a plurality of different methods for performing the jumping operation of said machining electrode;

a status detecting unit for detecting machining status data necessary for the stored methods;

a status memory section for storing information representing at least one of present machining states, past machining states and machining conditions detected by said status detecting unit; and

an inference section for combining a plurality of results obtained by said stored methods in accordance with the information stored in said status memory section, thereby providing an optimal jumping operation, each of the stored different methods for performing the jump operation using information stored in said status memory that is not used by any other method to change the same machining state.

6. The application control apparatus as defined in claim 5, wherein said inference section includes means for averaging the plurality of results obtained by said plurality of different methods to provide the optimal machining states.

7. An application control apparatus for a machining unit in which machining conditions can be changed,

said apparatus comprising:

a first arrangement group comprising;

a knowledge memory section for storing a plurality of different methods of changing machining conditions;

a state recognizing section for detecting machining states and processing signals;

a status memory section for storing information representing at least one of machining states provided by said state recognizing section and set machining conditions; and

an inference section for obtaining optimal machining conditions according to the information stored in said status memory section and said methods stored in said knowledge section; and

a second arrangement group comprising;

a time-series data recording section for recording time-series data of said set machining conditions, said machining states provided by said state recognizing section and machining condition changing operations performed by an operator; and

a knowledge renewing section for extracting a machining method from said recorded time-series data, and for modifying said methods stored in said knowledge memory section in accordance with said extracted machining method;

said first arrangement group operable for changing said machining conditions of said machining unit according to machining conditions provided by said inference section;

said first and second arrangement groups are used to perform a machining operation when performing at least one of collecting and correcting machining methods of an operator, said first and second arrangement groups also being operable to renew a method provided by said knowledge renewing section and stored in said knowledge memory section in accordance with, at least a part of the machining conditions by said operator without use of an output of said inference section.

8. A machining unit application control unit for an electric discharge machine which has a detector for detecting when a relative position of a machining electrode and a workpiece is equal to a predetermined value and is controlled by a numerical control unit, comprising:

a first memory section for storing a plurality of different methods for controlling a speed at which an electrode and a workpiece move towards each other such that a relative position of said electrode and said workpiece can be detected, such that a frequency of the operation can be determined, and such that after detection of the relative position of said electrode and workpiece being equal to a predetermined value, said electrode and workpiece are moved away from each other, and then subsequently said electrode and workpiece are moved towards each other until said relative position is again equal to said predetermined value, said first memory section also storing

a plurality of methods of determining a true detection position from a fluctuation in the detection position;

a second memory section for storing information representing state data of an electrode and a workpiece, and coordinates provided when the relative position of said electrode and said workpiece is equal to a predetermined value; and

a logic section for combining a plurality of results obtained by said plurality of methods stored in said first memory section in accordance with the information stored in said second memory section, thereby determining at least one of a speed and frequency of moving said electrode and said workpiece towards each other, and whether the relative position of said electrode and said workpiece is equal to said predetermined value.

9. An electric discharge machining method in which an electrode and a workpiece are moved relative to each other in such a manner that said electrode is moved towards said workpiece, and a machining operation is carried out while a distance between said electrode and said workpiece in a direction of movement of said electrode is being maintained constant by a servo control, and while one of said electrode and workpiece is being oscillated in directions perpendicular to the direction of movement of said electrode, said method comprising:

determining machining environmental factors including machining solution jet pressure, machining area, machining depth and oscillation radius to determine machining operation completion determining parameters, said parameters including a difference range between a discharge machining voltage and a reference voltage, and a time duration within said range of difference; and

determining when a machining operation completion operation is carried out in accordance with whether said machining operation completion determining parameters are satisfied by detecting values provided during machining.

10. An electric discharge machine in which an electrode and a workpiece are moved relative to each other in such a manner that said electrode is moved towards said workpiece, and a machining operation is carried out while a distance between said electrode and said workpiece in a direction of movement of said electrode is maintained constant by a servo control, and while one of said electrode and workpiece is being oscillated in directions perpendicular to the direction of movement of said electrode, said machine comprising:

a first memory section for storing a plurality of different methods for determining machining environmental factors, said factors including machining solution jet pressure, machining area, machining depth and oscillation radius;

a second memory section for storing information representing at least one of present machining states, past machining states and machining environmental conditions; and

a logic section for combining a plurality of results obtained by said plurality of methods stored in said first memory section in accordance with the information stored in said second memory section, to obtain a machining operation completion determining parameter, and to determine a machining operation completion according to said obtained parameter.