Method and apparatus for improved inspection and classification of attributes of a workpiece

• US 6,272,437 B1
• Filed: 04/17/1998
• Issued: 08/07/2001
• Est. Priority Date: 04/17/1998
• Status: Expired due to Term

• Current Assignee: Usnr/Kockums Cancar Company (USNR, LLC)
• Original Assignee: CAE Incorporated
• Inventors: McGuire, Michael, Johnson, Emeric, Ogloff, Harry, Skocic, Zvonimr, Woods, Steve C.
• Primary Examiner(s): ASSOUAD, PATRICK J
• Application Number:
  US09/061,723
• Time in Patent Office: 1,208 Days
• Field of Search: 702/35, 702/84, 702/81, 700/110, 700/109, 700/171, 700/159, 709/203, 709/315, 709/328
• US Class Current: 702/35
• CPC Class Codes: G01N 23/083 the radiation being X-rays
• CPC Class Codes: G01N 23/16 the material being a moving sheet or film
• CPC Class Codes: G01N 23/18 Investigating the presence of flaws defects or foreign matter
• CPC Class Codes: G07C 3/146 during manufacturing process

Abstract

An apparatus for detecting the probable existence, location, and type of defects in a workpiece is described. The apparatus includes a sensor subsystem, an optimizer, a control subsystem, and a computer system having a processor and computer readable memory. Sensor subsystem senses a first section of the workpiece and produces signals corresponding to a physical characteristic of the workpiece. The computer system is configured to generate a workpiece model based on the signals produced by the sensor subsystem. In an alternate embodiment, a defect assembler can be provided to merge signals from a plurality of sensor subsystems. The defect assembler can also be configured to generate the workpiece data model. The optimizer is configured to generate workpiece segmentation recommendations based on the workpiece data model. The processor is configured with a first producer thread program which, in response to the receipt of a first set of signals by the computer system, receives a data subscription request from a subsystem which uses data and transmits the signals from the computer readable memory to the generator of the data subscription request. The processor is further configured to generate a second producer thread in response to storage of a second set of signals in the computer readable memory. The second producer thread is configured to receive one of the data subscription requests and selectively send the second set of signals to the generator of the data subscription request. A tracking device for tracking selective kinematics of a workpiece moving through a plant is also disclosed. The tracking device includes an encoder wheel configured to tangentially contact a workpiece and rotate at an angular velocity coincident with the linear velocity of the workpiece. The tracking apparatus further includes a drive mechanism for driving the encoder wheel at a first angular velocity approaching the angular velocity of the encoder wheel which is coincident with the linear velocity of the workpiece. The tracking device also includes a signal generator configured to interact with the encoder wheel and generate a signal in response to the angular velocity of the encoder wheel. The tracking apparatus can be incorporated into the apparatus for detecting defects within a workpiece by providing the signal from the signal generator to the control subsystem.

Claims

1. An apparatus for detecting the probable existence, location, and type of defects in a workpiece, comprising:

a signal processor having a computer readable memory;

a control subsystem; and

a sensor subsystem, wherein;

the sensor subsystem is configured to sense a first section of the workpiece and produce signals corresponding to at least one physical characteristic of the section of the workpiece and store the signals in the computer readable memory;

the processor is configured to read the signals from the computer readable memory, to verify the signals, to generate defect types by comparing the signals to a rule set, and to generate a data model of the workpiece section;

the control subsystem is configured to generate a workpiece section identifier to specifically identify a workpiece section being sensed and provide the workpiece section identifier to the processor; and

the processor is further configured to receive the signals for the first workpiece section to a first workpiece processing thread after receiving the associated workpiece section identifier, and to generate a second workpiece processing thread to receive signals from a second workpiece section, and wherein the signals in the first workpiece processing thread are processed to generate the data model of the first workpiece section prior to the processing of the signals in the second workpiece processing thread.

2. The apparatus of claim 1 further comprising:

a plurality of sensor subsystems, each sensor subsystem configured to sense the first section of the workpiece and produce signals corresponding to selected physical characteristics of the section of the workpiece; and

a defect assembler configured to receive the signals from the plurality of sensor subsystems and store them in the computer readable memory, wherein;

the processor is configured to read the signals from the memory, to verify the signals, to generate defect types by combining the signals, by comparing the signals to one another and by comparing the signals to the rule set, and to generate the data model of the workpiece section.

3. The apparatus of claim 1 wherein the physical characteristic of the section is a profile characteristic.

4. The apparatus of claim 2 wherein the physical characteristics are selected from the group consisting of a dimensional characteristic, a profile characteristic, and a defect characteristic.

5. The apparatus of claim 2 wherein the processor is configured to transmit data models of workpiece sections to the defect assembler, and to generate an additional workpiece processing thread each time a data model of an additional workpiece section has been transmitted to the defect assembler.

6. The apparatus of claim 5 wherein the processor is further configured to:

generate and transmit from the first workpiece processing thread a first workpiece data model after the signals for the first workpiece section have been received by the processor;

while the first workpiece data model is being generated, receive signals for the second workpiece data model; and

generate and transmit from the first workpiece processing thread a second workpiece data model after the signals for the second workpiece section have been received by the processor.

7. An apparatus for detecting the probable existence, location, and type of defects in a workpiece, comprising:

a sensor subsystem configured to sense a first section of the workpiece and produce signals corresponding to at least one physical characteristic of the section of the workpiece;

a defect assembler configured to generate defect assembler data subscription requests, to receive the signals, and to generate a workpiece data model based on the signals;

an optimizer configured to generate workpiece segmentation recommendations based on the workpiece data model, and generate optimizer data subscription requests;

a computer system having a processor and computer readable memory, wherein;

the computer system is configured to receive signals from the sensor subsystem and store them in the computer readable memory; and

the processor is configured with a first producer thread program which, in response to the receipt of a first set of signals by the computer system, receives one of the data subscription requests and transmits the first set of signals from the computer readable memory to the generator of the data subscription request; and

wherein the processor is further configured to generate a second producer thread in response to storage of a second set of signals in the computer readable memory, the second producer thread being configured to receive one of the data subscription requests and selectively send the second set of signals to the generator of the data subscription request.

8. The apparatus of claim 7 wherein the characteristic is selected from the group consisting of a dimensional characteristic, a profile characteristic, and a defect characteristic.

9. An apparatus for characterizing a workpiece, comprising:

an interface controller;

a plurality of producer units configured to produce data relevant to characterization to the workpiece, wherein the producer units are selected from the group consisting of sensor subsystems configured to sense features of the workpiece and generate signals in response thereto, a defect assembler configured to generate a workpiece data model, an optimizer configured to produce a refined workpiece data model and generate workpiece segmentation recommendations based on the refined workpiece data model, and a controller configured to determine the position of the workpiece during sensing and segmentation, wherein the producer units are configured to notify the interface controller that workpiece data is available from the producer unit; and

a plurality of consumer units configured to use data relevant to characterization of the workpiece, wherein the consumer units are selected from the group consisting of an optimizer configured to use the refined workpiece model to generate workpiece segmentation recommendations, a defect assembler configured to use signals from the sensor subsystems to generate the workpiece data model, a host computer configured to store workpiece characterization data, and user interfaces configured to display workpiece characterization data;

wherein workpiece characterization data are selected from the group consisting of signals from the sensor subsystems, the workpiece data model, and the refined workpiece data model, wherein the consumer units subscribe to selected workpiece characterization data;

wherein the interface controller comprises a processor configured to;

generate producer threads to respond to workpiece characterization data subscriptions from the consumer units in response to notification from the producer units that workpiece data is available from the producer unit; and

send workpiece characterization data to selected consumer units in response to workpiece characterization data subscriptions from the selected consumer units.

10. The apparatus of claim 9 wherein the processor is further configured to generate consumer threads in response to receipt of a consumer server object from a consumer unit, wherein the consumer thread subscribes the consumer unit to workpiece characterization data.

11. The apparatus of claim 9 wherein the processor is further configured to delete producer threads in response to workpiece characterization data having been sent to selected consumer units.

12. A workpiece characterization system, comprising:

at least one producer subsystem configured to produce a set of services relating to physical characteristics of a workpiece;

at least one consumer subsystem configured to consume the set of services; and

an interface controller configured to exchange data between the subsystems in a generic, scalable manner, comprising;

an object-oriented producer application program interface (API) configured for use on a multi-threaded, client-server operating system, comprising producer routines configured to;

initialize producer server objects and producer client objects;

to receive requests for data from a consumer subsystem via said producer client objects;

to send acknowledgments to a consumer subsystem in response to requests from the consumer subsystem via said producer server objects;

to send data to a consumer subsystem in response to requests from the consumer subsystem via said producer server objects; and

an object-oriented consumer application program interface (API) configured for use on a multi-threaded, client-server operating system, comprising consumer routines configured to;

initialize consumer server objects and consumer client objects;

to send requests for data to a producer subsystem via said consumer server objects;

to receive acknowledgments from a producer subsystem in response to requests from the producer subsystem via said consumer client objects; and

to receive data from a producer subsystem in response to requests from the producer subsystem via said consumer client objects.

13. The workpiece characterization system of claim 12 wherein at least one of the consumer subsystems comprises a consumer server having a producer subscription to data from at least one of the producer subsystems, and wherein the producer API further comprises a first producer server thread configured to first initialize a producer client object and then to reply to the producer subscription by connecting to the consumer server.

14. The workpiece characterization system of claim 13 wherein the producer API is further configured to generate a new producer server thread for connection to the consumer server upon connection of the first producer server thread to the consumer server.

15. The workpiece characterization system of claim 14 wherein:

producer threads are listed on a subscribe table accessible by consumer servers;

a producer server thread is disconnectable from a consumer server; and

upon disconnection of a producer thread from a consumer server, the producer thread is removed from the subscribe table.

16. The workpiece characterization system of claim 13 wherein the consumer API further comprises a plurality of consumer server threads each configured to create a dedicated connection to a producer subsystem.

17. An apparatus for detecting the probable existence, location, and type of defects in a workpiece, comprising:

a sensor subsystem configured to sense a first section of the workpiece and produce signals corresponding to at least one physical characteristic of the section of the workpiece;

a defect assembler configured to generate defect assembler data subscription requests, to receive the signals, and to generate a workpiece data model based on the signals;

an optimizer configured to generate workpiece segmentation recommendations based on the workpiece data model, and generate optimizer data subscription requests;

a computer controllable workpiece segmenter configured to segment a workpiece according to the segmentation recommendations;

a control subsystem configured to control the workpiece segmenter in response to the location of a workpiece within the apparatus and in response to the workpiece data model and the segmentation recommendations;

a computer system having a processor and computer readable memory, wherein;

the computer system is configured to receive signals from the sensor subsystem and store them in the computer readable memory; and

the processor is configured with a first producer thread program which, in response to the receipt of a first set of signals by the computer system, receives one of the data subscription requests and transmits the first set of signals from the computer readable memory to the generator of the data subscription request, wherein;

the processor is further configured to generate a second producer thread in response to storage of a second set of signals in the computer readable memory, the second producer thread being configured to receive one of the data subscription requests and selectively send the second set of signals to the generator of the data subscription request; and

a tracking device configured to track selected kinematics of a workpiece moving at a linear velocity within the apparatus, comprising;

an encoder wheel configured to tangentially contact a workpiece and to rotate at an angular velocity coincident with the linear velocity of the workpiece in response to contact between the encoder wheel and the workpiece;

a drive mechanism configured to drive the encoder wheel at a first angular velocity approaching an angular velocity of the encoder wheel coincident with the linear velocity of the workpiece; and

a signal generator configured to interact with the encoder wheel and generate a signal in response to the angular velocity of the encoder wheel and provide the signal to the control subsystem.