High-speed digital video serial link

• US 6,084,631 A
• Filed: 04/02/1997
• Issued: 07/04/2000
• Est. Priority Date: 03/24/1995
• Status: Expired due to Fees

• Current Assignee: Coastal Chromatics LLC (Intellectual Ventures LLC)
• Original Assignee: PPT Vision, Inc. (Datalogic S.p.A.)
• Inventors: Paulsen, Mark Thomas, Tonkin, Steven Wallace
• Primary Examiner(s): Ho, Tuan
• Assistant Examiner(s): MOE, AUNG SOE
• Application Number:
  US08/825,774
• Time in Patent Office: 1,189 Days
• Field of Search: 348/211, 348/212, 348/13, 348/15, 348/705, 348/12, 348/153, 348/86, 370/62, 370/89
• US Class Current: 348/211.6
• CPC Class Codes: H04N 21/23602 Multiplexing isochronously with the video sync, e.g. according to bit-parallel or bit-serial interface formats, as SDI
• CPC Class Codes: H04N 21/2381 Adapting the multiplex stream to a specific network, e.g. an Internet Protocol [IP] network transmission of MPEG streams over ATM H04L12/5601
• CPC Class Codes: H04N 21/4342 Demultiplexing isochronously with video sync, e.g. according to bit-parallel or bit-serial interface formats, as SDI
• CPC Class Codes: H04N 21/4363 Adapting the video stream to a specific local network, e.g. a Bluetooth® network
• CPC Class Codes: H04N 21/4381 Recovering the multiplex stream from a specific network, e.g. recovering MPEG packets from ATM cells transmission of MPEG streams over ATM H04L12/5601
• CPC Class Codes: H04N 7/181 for receiving images from a plurality of remote sources

Abstract

A system for bidirectional digital serial communication and control of remote units including video cameras and input/output devices in machine vision systems. The communication system includes a main processor, communication hubs and remote units. The system is capable of monitoring and controlling the remote units in real-time while receiving video data images from the remote video cameras. Digital signals are transmitted in two different protocols; one for data communications, and one for control communications.

Claims

1. A machine vision control system for use in a manufacturing environment using two-directional high speed serial digital transmissions comprising:

a main processor that receives packaged digital data and control signals and that transmits packaged digital data and control signals, the main processor including an analyzer circuit that analyzes received video image data and that generates and transmits a packaged digital first control signal that includes a content-analysis response based upon content of the video image data;

a primary communication hub having a first interface and a plurality of second interfaces, the first interface connected to the main processor through a serial communication bus that transmits and receives the packaged digital data and control signals;

a plurality of remote video cameras each having a third interface that is connected to one of the plurality of second interfaces for two-directional communication with the primary communication hub; and

a first trigger source responsive to a manufacturing process or assembly step, that provides a signal commanding that one of the plurality of remote video cameras acquire an image;

wherein

the primary communication hub is adapted to generate a priority response to a high priority request signal,

the priority response being inserted between the beginning and end of transmission of a digital data packet carrying video information from one of the remote video cameras to the main processor, and wherein real-time manufacturing operations are performed using the first control signal.

2. The machine vision control system of claim 1 further including at least one secondary communication hub connected to one of the plurality of second interfaces of the primary communication hub for managing communications between the primary communication hub and additional remote video cameras.

3. The machine vision control system of claim 1 wherein the packaged digital data signals comprise a source address code for identifying an address origin of the digital data signal, a destination address code identifying a final address destination of the digital data signal, a priority code identifying a priority of the transmission, and digital data.

4. The machine vision control system of claim 3 wherein the packaged digital data signals further include a data error detection code for detecting errors in the digital data, and a device identification code to identify a type of camera originating the transmission.

5. The machine vision control system of claim 1 wherein the packaged digital control signals comprise a source address code for identifying an address origin of the digital control signal, a destination address code identifying a final address destination of the digital control signal, a priority code identifying a priority of the transmission, and digital control commands.

6. The machine vision control system of claim 1 further including at least one remote input/output unit connected to the primary communication hub for at least receiving transmissions from the primary communication hub.

7. The machine vision control system of claim 6 where the remote input/output unit is an industrial control network.

8. The machine vision control system of claim 6 where the remote input/output unit is a strobe light.

9. A machine vision control system for use in a manufacturing environment using two-directional high speed serial digital transmissions comprising:

a main processor that receives packaged digital video data signals and transmitting packaged digital video data signals at a data rate of up to at least about 330 mega bits per second, the main processor including an analyzer circuit that analyzes received video image data and that generates a content-analysis response based upon content of the video image data;

at least one remote video camera connected to the main processor that provides two-directional communication of the serial digital video data and control signals with the main processor; and

a trigger source that provides a signal commanding that a remote video camera acquire an image at a specific point in time, wherein real-time manufacturing operations are performed using the content-analysis response.

10. The machine vision control system of claim 9 wherein the digital video data signals comprise a source address code for identifying an address origin of the digital video data signal, a destination address code identifying a final address destination of the digital video data signal, a priority code identifying a priority of the transmission, and digital data.

11. The machine vision control system of claim 10 wherein the digital video data signals further include a data error detection code for detecting errors in the digital video data signal, and a device identification code to identify a type of video camera originating the transmission.

12. The machine vision control system of claim 9 wherein the digital control signals comprise a source address code for identifying an address origin of the digital control signal, a destination address code identifying a final address destination of the digital control signal, a priority code identifying a priority of the transmission, and digital control commands.

13. The machine vision control system of claim 9 further including at least one remote input/output unit connected to the main processor for at least receiving transmissions from the main processor.

14. A machine vision control system for use in a manufacturing environment using two-directional high speed serial digital transmissions between at least a main processor and a communication hub, the system comprising:

the main processor comprising a receiver for receiving packaged digital signals including a header and either digital data and control signals, a memory for storing the received digital signals, and a transmitter for transmitting packaged serial digital signals, the main processor including an analyzer circuit for analyzing received video image data and generating a content-analysis response based upon content of the video image data;

the communication hub for at least distributing transmissions between the main processor and a plurality of remote video cameras, the communication hub comprising a main processor interface connected to the main processor for communicating with the main processor and a plurality of remote video camera interfaces connected to the plurality of remote video cameras for communication with the plurality of remote video cameras,

the main processor interface comprising a receiver for receiving digital transmissions from the main processor, a processor, a first transmitter for transmitting signals to at least one remote video camera, and a second transmitter for transmitting packaged signals to the main processor,

each one of the plurality of remote video camera interfaces comprising a receiver associated with each of the plurality of remote video cameras, a controller associated with each receiver for controlling transmissions from one of the plurality of remote video cameras, and a memory for storing the transmissions;

a video camera having a communication hub interface for communication with the communication hub, the video camera comprising a transmitter, a receiver, and a controller for controlling communication with the communication hub; and

a first trigger source for providing a signal commanding that one of the plurality of remote video cameras acquire an image at a specific point in time, the communication hub adapted to generate a priority response to a high priority request signal transmitted from the remote camera or from the first trigger source, and generate a signal to acquire an image in response to the first trigger source, and wherein real-time manufacturing operations are controlled based on the content-analysis response.

15. The machine vision control system of claim 14 further including at least one analog video camera connected to the communication hub.

16. A main processor for two-directional high speed digital serial communication in a machine vision control system for use in a high-speed manufacturing environment having a plurality of remote video cameras, the main processor comprising:

a receiver for receiving packaged digital video data or control signals including a header, the packaged digital video data or control signals;

a controller for separating the header from the digital video data or control signals;

a memory for storing the digital video data or control signals;

an analyzer circuit for analyzing received video image data and generating a content-analysis response based upon content of the video image data; and

a transmitter for transmitting packaged digital signals, the transmitted packaged digital signals including a header in response to the received packaged digital video data or control signals, and wherein real-time manufacturing operations are controlled based on the content-analysis response.

17. A video camera interface for two-directional high speed digital serial communication in a machine vision control system between a plurality of remote video cameras and a processor, the video camera interface comprising:

a receiver for receiving packaged digital signals from the processor;

a transmitter for transmitting packaged digital transmissions comprising a header and either digital video data or digital control signals;

a controller for controlling communication with the processor; and

wherein the video camera interface is adapted to send a signal requesting that an external input/output device coupled to a primary communication hub be activated to flash illumination for a camera at a specific point in time, and wherein real-time manufacturing operations are performed using resulting real-time high-speed digital transmissions for control signals, said control signals including the signal requesting that the external input/output device'"'"'s flash illumination be activated.

18. The video camera interface according to claim 17, further comprising

a trigger activation circuit that receives a trigger signal and activates acquisition of a particular image corresponding to the trigger signal by the video camera.

19. A communication hub for two-directional high speed digital serial communication in a machine vision control system between a plurality of remote video cameras and a processor, the hub comprising:

a processor interface connected to the processor; and

a plurality of remote video camera interfaces connected to the plurality of remote video cameras, including a first remote video camera interface and a second remote video camera interface;

the processor interface comprising a receiver for receiving packaged digital transmissions from a main processor, a first transmitter for transmitting packaged serial digital signals to at least one of the plurality of remote video cameras on the first remote video camera interface, and a second transmitter for transmitting packaged serial digital signals to at least one of the plurality of remote video cameras over the second remote video camera interface, and a third transmitter for transmitting packaged signals to the main processor over the processor interface;

each one of the plurality of remote video camera interfaces comprising a receiver associated with each of the plurality of remote video cameras, a controller associated with each receiver for controlling transmissions from one of the plurality of remote video cameras, and a memory for storing the transmissions; and

the communication hub adapted to activate, at a specific point in time, an external flash illumination input/output device in response to a request signal transmitted from one of the plurality of remote video cameras, and wherein real-time manufacturing operations are performed using resulting real-time high-speed digital transmissions for control signals, said control signals including the request signal.

20. The communication hub of claim 19 further including a control circuit for directly communicating with at least one input/output device.

21. The communication hub of claim 19 further including a control circuit for directly controlling at least one output device.

22. A method of operating a machine vision control system having a plurality of remote video cameras and a main processor, the method comprising the steps of:

receiving an input trigger signal from a trigger source;

generating a first digital packet based upon the input trigger signal;

capturing an image of an object with one of the plurality of remote video cameras at a specific point in time in response to the first digital packet;

converting the image to one or more digital video signal packets including an appended first header;

serially transmitting the one or more digital video signal packets from one of the plurality of remote video cameras to a communication hub;

multiplexing digital video signal packets from the remote video cameras, evaluating a destination address identifier included in the first header, and transmitting at least some of the digital signal packets to the main processor; and

analyzing the digital video signal packets with the main processor to evaluate the captured image and generating a content-analysis response signal, and wherein real-time manufacturing operations are controlled based on the content-analysis response signal.

23. The method of claim 22 further including the steps of:

serially transmitting digital control signal packets including a second header from the main processor to the communication hub; and

using the communication hub, evaluating a destination address identifier included in the second header, and transmitting at least some of the packets to at least one the remote video cameras.

24. The method of claim 22 further including the steps of:

transmitting a high priority digital signal comprising a header having a high priority identifier from a camera or other I/O device to the communication hub;

interrupting a digital signal being transmitted by the communication hub to the main processor in response to the high priority digital signal and transmitting the high priority digital signal from the communication hub to the main processor; and

completing the transmission of the interrupted digital signal.

25. The method of claim 22 further including the steps of;

transmitting a digital signal request packet from one of the remote video cameras or other I/O device where the destination address is an address corresponding to the communication hub;

evaluating the destination address identifier at the communication hub; and

responding to the digital signal request packet with the communication hub.

26. The method of claim 22 further comprising the steps of:

transmitting a control signal from the communication hub to a camera requesting that the camera capture an image of an object;

transmitting from the camera to the communication hub a high priority signal requesting that a strobe light be activated; and

analyzing the high priority signal with the communication hub and transmitting a control signal to the strobe light from the communication hub commanding the activation of the strobe light.

27. The method of claim 22 further comprising the steps of:

generating a camera activation command and transmitting the command from the communication hub to the one of the plurality of remote video cameras in response to the received input trigger signal;

generating a strobe light activation request signal with the one of the plurality of remote video cameras; and

activating a strobe light in response to the strobe light activation request signal.

28. A machine vision control system for use in a manufacturing environment using high speed serial digital communications comprising:

one or more remote video cameras, each camera having a digital serial camera interface that (a) transmits packaged serial digital data representing an image acquired by the camera, and that (b) receives a command to, at a specific point in time, acquire an image;

a main processor having a processor interface coupled to the camera interface, wherein the processor interface includes a receiver that receives packaged serial digital data and packaged serial digital control signals and a transmitter that transmits packaged serial digital data signals and packaged serial digital control signals, the main processor further having an analyzer circuit that analyzes received video image data and generates a content-analysis response signal based upon content of the video image data, and wherein high-speed manufacturing operations are controlled based on the content-analysis response signal,

wherein a protocol used by the main processor receiver that receives packaged serial digital data or packaged serial digital control signals is also used by the main processor transmitter that transmits packaged serial digital data signals or packaged serial digital control signals.

29. The machine vision control system of claim 28, further comprising:

a primary communication hub having a first interface and one or more second interfaces, the first interface coupled to the main processor through a serial communication bus that transmits and receives the packaged digital data and control signals, and each one of the one or more second interfaces coupled to a respective one of the one or more remote video cameras to transmit and receive packaged digital data and control signals, wherein the primary communication hub is adapted to generate a priority response to a high priority request signal transmitted from the plurality of remote cameras or a trigger source, the priority response being inserted between the beginning and end of transmission of a digital data packet carrying video information from one of the remote video cameras to the main processor, and to generate a signal to acquire an image in response to the trigger source.

30. The machine vision control system of claim 29, wherein the primary communication hub further includes a memory, and wherein image data from a first one of the one or more video cameras is stored in the memory while image data from a second one of the one or more video cameras is communicated from the hub to the main processor.

31. The machine vision control system of claim 29, wherein the primary communication hub is adapted, based on the priority response, to insert a second serial digital data packet based on the high-priority request signal into a middle portion of a first serial digital data packet.

32. The machine vision control system of claim 31, wherein each byte transmitted on the processor interface includes a bit indicating whether the byte is a header byte or not in order to facilitate detection of inserted data packets.

33. The machine vision control system of claim 29, wherein the content-analysis response signal is used to control a manufacturing process input/output device.

34. The machine vision control system of claim 28 wherein the communication link used by the main processor includes a fiber optic link.

35. The machine vision control system of claim 28, wherein a communication link used by the main processor receiver that receives packaged serial digital data and packaged serial digital control signals and by the main processor transmitter that transmits packaged serial digital data signals and packaged serial digital control signals allows simultaneous transmission and reception of data.