Optical reading system and method of operation

• US 8,519,321 B2
• Filed: 11/24/2009
• Issued: 08/27/2013
• Est. Priority Date: 02/10/2009
• Status: Active Grant

• Current Assignee: Itron, Inc.
• Original Assignee: Consolidated Edison Company of New York Incorporated (Consolidated Edison Incorporated), Itron, Inc.
• Inventors: Barna, Anthony F., Nardo, Lawrence P., Melvin, Charles W. Jr., Walton, Jason P., Kressner, A. Arthur
• Primary Examiner(s): Epps, Georgia Y
• Assistant Examiner(s): Wyatt, Kevin
• Application Number:
  US12/624,660
• Publication Number:
  US 20100200732A1
• Time in Patent Office: 1,372 Days
• Field of Search: 250/221, 250/557, 382/203, 382/206, 382/199, 345639-641
• US Class Current: 250/221
• CPC Class Codes: G01D 4/008 Modifications to installed utility meters to enable remote reading
• CPC Class Codes: G01D 5/34715 Scale reading or illumination devices
• CPC Class Codes: G01J 1/02 Details
• CPC Class Codes: G01J 1/0204 Compact construction
• CPC Class Codes: G01J 1/0219 Electrical interface; User interface
• CPC Class Codes: G01J 1/0228 Control of working procedures; Failure detection; Spectral bandwidth calculation
• CPC Class Codes: G01J 1/0271 Housings; Attachments or accessories for photometers
• CPC Class Codes: G01J 1/04 Optical or mechanical part supplementary adjustable parts
• CPC Class Codes: G01J 1/0403 Mechanical elements; Supports for optical elements; Scanning arrangements
• CPC Class Codes: G01J 1/0411 using focussing or collimating elements, i.e. lenses or mirrors; Aberration correction
• CPC Class Codes: G01J 1/42 using electric radiation detectors optical or mechanical part G01J1/04; by comparison with a reference light or electric value G01J1/10
• CPC Class Codes: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y04S 20/30 Smart metering, e.g. specially adapted for remote reading

Abstract

An optical sensor for detecting motion or movement in an area of interest and a method of operation is provided. The system includes a CMOS sensor having an array of pixels that captures images in an area of interest. The system monitors the average pixel value for the array to define a first state. If the average pixel value changes beyond a defined threshold, the system defines a second state. For each change in state, a signal is generated. In one embodiment, the optical sensor is used with a meter having a dial with an indicator. The optical sensor generates a signal each time the indicator passes through the area of interest to allow for the remote monitoring of a consumable commodity.

Claims

1. A method of operating a sensor comprising the steps of:

capturing a first image with a sensor having an array of pixels;

generating a first image value from said first image, wherein said first image value is an average of individual pixel values in said array of pixels;

storing said first image value;

comparing said first image value to a threshold;

generating a signal if said first image value exceeds said threshold;

capturing a second image with said sensor;

generating a second image value from said second image, wherein said second image value is an average individual pixel values in said array of pixels;

comparing said second image value to said first image value;

determining if said first image exceeds said threshold and said second image does not exceed said threshold; and

generating said signal if said first image exceeds said threshold and said second image does not exceed said threshold;

reducing power consumption in said sensor after generating said signal;

setting an interrupt timer before said step of reducing power consumption; and

,

generating an interrupt signal when said interrupt timer expires.

2. The method of claim 1 further comprising the step of incrementing a counter in response to said signal.

3. A method of operating a system having a sensor capable of acquiring images in an area of interest, said method comprising:

acquiring a first image with said sensor;

determining a first image value for said first image, wherein said first image value is an average pixel value for said first image;

setting a previous-state variable to a first value if said first image value is above a threshold value;

setting said previous-state variable to a second value if said first image value is at or below said threshold value;

acquiring a second image with said sensor;

determining a second image value for said second image, wherein said second image value is an average pixel value for said second image;

setting a new-state variable to said first value if said second image value is above said threshold value;

setting said new-state variable to said second value if said second image value is below said threshold value; and

,

comparing said new-state variable to said present-state variable and generating a signal if said new-state variable is equal to said second value and said previous-state value is equal to said first value;

initializing said sensor;

acquiring a third image before acquiring said first image;

determining a third image value from said third image, wherein said third image value is an average pixel value for said third image;

setting said threshold value based on said third image value;

setting said new-state variable equal to said previous-state variable; and

,

generating a signal in response to said new-state variable being set equal to said previous-state variable;

setting an interrupt timer;

operating said sensor in a low electrical power consumption mode; and

,

generating an interrupt signal when said interrupt timer expires.

4. The method of claim 3 wherein said signal increments a counter on an advanced metering infrastructure meter.

5. An optical sensing system comprising:

an optical sensor including an array of pixels, wherein each of said pixels generate a second signal corresponding to a quantity of light received by each of said pixels for said first acquired image, and wherein each of said pixels generate a third signal corresponding to a quantity of light received by each of said pixels for said second acquired image;

a lens adjacent said optical sensor and arranged to focus said optical sensor on an area of interest;

a controller electrically coupled to said optical sensor, said controller having a first processor that is responsive to executable computer instructions for determining if an object is present in the area of interest in a first acquired image and not present in a second acquired image and transmitting a first signal in response to said object being present in said first acquired image and not present in said second acquired image, wherein said second acquired image is acquired later in time than said first acquired image;

a meter operably coupled to received said first signal from said controller, said meter having a second processor responsive to executable instructions to increment a consumption counter in response to receiving said first signal;

wherein said first processor is further responsive to said second signals to generate a first average pixel value for said array of pixels for said first acquired image;

wherein said first processor is further responsive to executable computer instructions for comparing said first average pixel value and said second average pixel value and generating said first signal if said first average pixel value exceeds a threshold and said second average pixel value does not exceed a threshold.

6. The system of claim 5 wherein said first processor is further responsive to executable computer instructions to initiate an interrupt timer after comparing said first average pixel value to said second average pixel value.

7. The system of claim 6 wherein said first processor is further responsive to executable computer instructions to activate a low power consumption mode for said controller after initiating said interrupt timer.