self-diagnosing system for encoder

• US 20050171713A1
• Filed: 02/03/2005
• Published: 08/04/2005
• Est. Priority Date: 02/03/2004
• Status: Active Grant

• Current Assignee: Fanuc Ltd (Fanuc Corporation)
• Original Assignee: Fanuc Ltd (Fanuc Corporation)
• Inventors: Miyamoto, Hajime, Taniguchi, Mitsuyuki, Kikuchi, Hirofumi
• Granted Patent: US 7,209,862 B2
• Time in Patent Office: Days
• US Class Current: 702/69
• CPC Class Codes: G01D 5/24457 Failure detection
• CPC Class Codes: G01D 5/24461 by redundancy or plausibility

Abstract

A self-diagnosing system for an encoder. The system includes an encoder circuit for outputting information detected by an encoder; a data preparing section provided in the encoder circuit and preparing data representing a state of an abnormal-state judgment factor in connection with at least one of the encoder and an electric motor combined with the encoder; a signal generating section provided in the encoder circuit and generating an abnormal-state signal when the data prepared in the data preparing section represents an abnormal state of the abnormal-state judgment factor; and a storage section provided in the encoder circuit and storing the data representing a state of the abnormal-state judgment factor when the signal generating section generates the abnormal-state signal. The storage section may store the data prepared in the data preparing section at a desired timing not later than the instant the signal generating section generates the abnormal-state signal.

Claims

1. A self-diagnosing system for an encoder, comprising:

an encodes circuit for outputting information detected by an encoder;

a data preparing section provided in said encoder circuit, said data preparing section preparing data representing a state of an abnormal-state judgment factor in connection with at least one of the encoder and an electric motor combined with the encoder;

a signal generating section provided in said encoder circuit, said signal generating section generating an abnormal-state signal when said data prepared in said data preparing section represents an abnormal state of said abnormal-state judgment factor; and

a storage section provided in said encoder circuit, said storage section storing said data representing a state of said abnormal-state judgment factor when said signal generating section generates said abnormal-state signal.

2. A self-diagnosing system as set forth in claim 1, wherein said storage section stores said data prepared in said data preparing section at a desired timing not later than an instant said signal generating section generates said abnormal-state signal.

3. A self-diagnosing system as set forth in claim 1, wherein said data preparing section prepares plural pieces of data respectively representing states of plural abnormal-state judgment factors set in connection with predetermined check items for the at least one of the encoder and the electric motor;

wherein said signal generating section generates said abnormal-state signal when at least one of said plural pieces of data prepared in said data preparing section represents an abnormal state in said abnormal-state judgment factor corresponding thereto; and

wherein said storage section stores said plural pieces of data respectively representing states of said plural abnormal-state judgment factors when the signal generating section generates said abnormal-state signal.

4. A self-diagnosing system as set forth in claim 1, wherein said data prepared in said data preparing section includes at least one of:

data representing said state of said abnormal-state judgment factor in terms of a position of the electric motor detected by the encoder;

data representing said state of said abnormal-state judgment factor in terms of a speed of the electric motor detected by the encoder;

data representing said state of said abnormal-state judgment factor in terms of a temperature of the encoder; and

data representing said state of said abnormal-state judgment factor in terms of a temperature of the electric motor.

5. A self-diagnosing system as set forth in claim 1, wherein said storage section further stores evidential data representing evidence of generation of said abnormal-state signal, when said signal generating section generates said abnormal-state signal, said evidential data being used as a basis of said data prepared in said data preparing section.

6. A self-diagnosing system as set forth in claim 1, further comprising a moving-distance measuring section provided in said encoder circuit, said moving-distance measuring section measuring an accumulated total moving distance of the encoder, wherein said storage section further stores said accumulated total moving distance measured in said moving-distance measuring section when said signal generating section generates said abnormal-state signal.

7. A self-diagnosing system as set forth in claim 1, further comprising an operating-time measuring section provided in said encoder circuit, said operating-time measuring section measuring an accumulated total operating time of the encoder, wherein said storage section further stores said accumulated total operating time measured in said operating-time measuring section when said signal generating section generates said abnormal-state signal.