Optical sensor apparatus and method for remotely monitoring a utility meter or the like

• US 4,680,704 A
• Filed: 12/28/1984
• Issued: 07/14/1987
• Est. Priority Date: 12/28/1984
• Status: Expired due to Fees

• Current Assignee: Telemeter Corporation
• Original Assignee: Telemeter Corporation
• Inventors: Case, Steven K., Kackman, Gerald M., Konicek, Lawrence R.
• Primary Examiner(s): Lall, Parshotam S.
• Assistant Examiner(s): Juffernbruch, Daniel W.
• Application Number:
  US06/687,089
• Time in Patent Office: 928 Days
• Field of Search: 340/870.02, 340/870.28, 340/870.29, 340/688, 364/525, 364/483, 364/516, 250/231 SE, 356/71, 356/138, 356/141, 356/150, 356/152, 382/1, 382/65, 324/157, 377/17, 358/93, 358/107
• US Class Current: 382/100
• CPC Class Codes: G01D 4/004 Remote reading of utility meters to a fixed location
• CPC Class Codes: G01D 4/008 Modifications to installed utility meters to enable remote reading
• CPC Class Codes: G01R 1/08 Pointers; Scales; Scale illumination
• 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

The present invention relates to an optical sensor apparatus (21) for remotely monitoring a utility meter or the like. The optical sensor apparatus (21) includes optically sensitive detector, in this case, a dynamic RAM device (40) which consists of an array (42, 44) of light sensitive elements. Light from a light source (56) is reflected off the faceplate (52) of the meter. Microprocessor control system (100) operatively interconnected to the optically sensitive dynamic RAM device (40) controls the exposure of the RAM device (40) to the light. The microprocessor control system (100) further determines the angular position of the individual pointer members (50) of the meter by correlating a binary image stored in memory to a predetermined geometic shape. The microprocessor control system (100) further includes logic for converting the angular positions of the pointer members (50) of the meter stages to a decimal value representative of the meter reading. A transmitter device is operatively interconnected to the microprocessor control system (100) for transmitting the decimal values to a remote site.

Claims

1. An apparatus for optically sensing the angular position of a pointer member fixedly mounted on a rotatable shaft for rotational movement therewith about an axis of rotation, the apparatus comprising:

a. an infrared light source means for providing a source of infrared light;

b. mirror means cooperating with the infrared light source means for directing the infrared light generally toward the pointer member from a location generally forward of the pointer member;

c. retroreflective surface means disposed on generally one of two locations selected from a faceplate in back of the pointer member and the pointer member for providing a contrast between the pointer member and the faceplate in back of the pointer member, the retroreflective surface means reflecting the infrared light generally back in the direction from which it came toward the mirror means;

d. lens means for focusing the infrared light reflected by the retroreflective surface means;

e. optically sensitive image detector means including an array of light sensitive elements for receiving the infrared light focused thereon by the lens means, the optically sensitive image detector means including control circuitry means for controlling the operation of the image detector means, the control circuitry means including;

i. means for presetting each of the light sensitive elements to a predetermined voltage;

ii. means for initiating the exposure of the light sensitive elements to the infrared light;

iii. refreshing means for refreshing the light sensitive elements after a predetermined exposure interval wherein the voltage of each of the light sensitive elements is compared to a predetermined threshold voltage value and each of the light sensitive elements are provided with one of two nominal voltage values representative of the respective light sensitive elements having a voltage less than the threshold voltage value or greater than the threshold voltage value; and

iv. means for reading the nominal voltage value of each of the light sensitive elements and providing a binary output signal representative of the nominal voltage value; and

f. control means operatively interconnected to the image detector means for receiving the binary output signal and storing the binary output signal in memory means whereby a binary image of the pointer member is stored, the control means including;

i. exposure control means for controlling the exposure of the image detector means to the infrared light;

ii. location means for locating the axis of rotation of the pointer member, the location means including means for correlating the binary image of the pointer member stored in the memory means to a first predetermined geometric shape;

iii. angular position means cooperating with the location means for determining the angular position of the pointer member, the angular position means including means for correlating the binary image of an end portion of the pointer member with a second geometric shape rotatable relative to the binary image of the pointer member about the axis of rotation of the pointer member; and

iv. means for storing in memory means digital data representative of the angular position of the pointer member.

2. An apparatus in accordance with claim 1, wherein the mirror means includes beam splitter means for reflecting only a fraction of the infrared light directed thereon by the infrared light source.

3. An apparatus in accordance with claim 1, wherein the infrared light source means and the mirror means are offset from the axis of rotation of the pointer member, the mirror means cooperating with the infrared light source means for directing the infrared light generally toward the pointer member.

4. An apparatus in accordance with claim 1, wherein the infrared light source means is offset from the axis of rotation of the pointer member and directs the infrared light in a direction generally away from the pointer member, the mirror means including two separate, spaced apart mirrors for directing the infrared light first generally transversely of the faceplate and second generally toward the pointer member whereby the mirror means do not obstruct visual viewing of the pointer member.

5. An apparatus in accordance with claim 1, further including transmission means operatively interconnected to the microprocessor means for transmitting the digital data representative of the angular position of the pointer member to a remote location.

6. An apparatus in accordance with claim 1, wherein the control means includes means for converting the angular position data to numerical data.

7. An apparatus in accordance with claim 1, wherein the image detector means includes a dynamic RAM means.

8. An optical sensor apparatus for reading a meter having one or more dial settings representative of the meter reading;

comprising;

a. light source means for providing a source of light, the light source means directing the light generally toward a faceplate of the meter;

b. reflecting means for providing contrast between operative parts of the meter by reflecting light received from the light source means;

c. lens means for focusing the light reflected off the meter;

d. optically sensitive image detector means including an array of light sensitive elements for receiving the light focused thereon by the lens means and retaining for a period of time a state indicative of the intensity of the light received; and

e. control means operatively interconnected to the image detector means for receiving the output signals from the light detector means representative of the light intensity to which the light sensitive elements of the image detector means are exposed and for storing values represented by the output signals whereby a digitized image of the meter is stored, the control means including means for determining dial settings of the meter by interpretation of the digitized image stored in the memory means.

9. An apparatus in accordance with claim 8, wherein said control means includes pattern recognition means for comparing the digitized image to a predetermined pattern whose X-Y coordinates are known.

10. An apparatus in accordance with claim 8, further including transmission means operatively interconnected to the control means for transmitting the digitized image to to a remote location.

11. An apparatus in accordance with claim 8, further including transmission means operatively interconnected to the control means for transmitting the digital data representative of the dial settings to a remote location.

12. An optical sensor apparatus for remotely reading a multistage meter, each stage of the meter including a pointer member affixed to a rotatable shaft for rotation about an axis of rotation, adjacent pointer members being angularly displaced on a 10:

1 ratio with respect to the pointer member of the next higher adjacent stage so as to record decimal readings and measurements, the optical sensor apparatus comprising;

a. a support structure means for supporting at least some of the elements of the optical sensor apparatus on the meter under a transparent cover placed over the meter to enclose the stages;

b. infrared light source means for providing a source of infrared light;

c. mirror means for reflecting the infrared light generally toward a faceplate of the meter where the stages are positioned;

d. retroreflective surface means disposed proximate the surface of the meter faceplate in back of the pointer members for reflecting the infrared light generally back toward the infrared light source means in the direction from which the light came, the pointer members reflecting less infrared light than the retroreflective surface means so as to provide an effective contrast therebetween;

e. lens means for receiving the infrared light reflected from the retroreflective surface means and focusing the infrared light;

f. optically sensitive dynamic RAM means including an array of individual light sensitive elements arranged in rows and columns for receiving the infrared light focused thereon by the lens means, each of the light sensitive elements providing a binary output signal having one of two binary values representative of the amount of light to which each of the individual light sensitive elements are exposed, a first value being representative of an exposure below a predetermined threshold value and a second value being representative of an exposure above a predetermined threshold value;

g. control means operatively interconnected to the optically sensitive dynamic RAM means for receiving the binary output signals from the optically sensitive dynamic RAM means and for storing the binary values of the binary output signals in memory means whereby a binary image representative of the meter stages is stored in the memory means, the control means including;

i. means for controlling the exposure of the optically sensitive dynamic RAM means to the infrared light;

ii. means for determining the angular position of each of the individual pointers of the meter stages by correlating the binary image to predetermined geometric shape means;

iii. means for converting the angular positions of the pointer members of the meter stages to numerical value representative of the meter reading; and

h. transmission means operatively interconnected to the control means for transmitting the numerical value representative of the meter reading to a remote site.

13. An apparatus in accordance with claim 12, wherein the support structure means includes an integral support structure removably mounted onto the meter, the integral support structure supporting the infrared light source means, the lens means, the mirror means, and the optically sensitive dynamic RAM means under the transparent meter cover.

14. An apparatus in accordance with claim 13, wherein the integral support structure is removably mounted onto the faceplate of the meter by threaded fasteners cooperating with the existing threaded apertures of the meter faceplate.

15. An apparatus in accordance with claim 12, wherein the mirror means includes two spaced apart mirrors, a first mirror for reflecting infrared light received from the infrared light source in a direction generally transverse of the meter faceplate, the infrared light source means directing the infrared light generally toward the first mirror and generally away from the meter faceplate, and a second mirror for reflecting the infrared light received from the first mirror in a direction generally toward the meter faceplate.

16. An apparatus in accordance with claim 12, wherein the retroreflective surface means includes bar code indicia means for identifying the meter, and a microprocessor means including means for reading the bar code from the binary image stored in the memory means.

17. An apparatus in accordance with claim 12, wherein the means for detecting the angular position of each of the pointer members includes axis location means for detecting the location of the axis of rotation of each of the pointer members in the binary image stored in the memory means by correlating the binary image of each of the pointer members to a circular geometric shape whose center XY coordinates are known, the axis location means moving the circular geometric shape around by selecting different XY coordinates for the circular geometric shape and comparing the binary values of the binary image lying within the area of the circular geometric shape at each of the selected XY coordinates, the axis of rotation of the respective pointer members being determined as the XY coordinates of the circular shape wherein a maximum number of the binary values are found having the first binary value representative of an exposure below the threshold value, the means for detecting angular position further including angular position means for detecting the angular orientation of each of the pointer members with respect to their respective axis of rotation by correlating the binary image of each of the pointer members to a triangular geometric shape whose angular orientation relative to the axis of rotation is known, the angular position means moving the triangular geometric shape around by selecting different XY coordinates for the triangular geometric shape and comparing the binary values of the binary image lying within the area of the triangular geometric shape at each of the selected XY coordinates, the angular position of the respective pointer member being determined as the angular orientation of the triangular geometric shape wherein a maximum number of the binary values are found having the first value representative of an exposure below the threshold value.

18. An apparatus in accordance with claim 12, wherein the control means includes means for transmitting the binary image of the meter stages to a remote site for visual display at the remote site, whereby the meter image can be visually monitored and analyzed.

19. An optical sensor apparatus for reading a meter having one or more indicators representative of the meter reading;

comprising;

a. light source means for providing a source of light, the light source means directing the light generally toward a faceplate of the meter;

b. lens means for focusing the light reflected off the meter faceplate;

c. optically sensitive image detector means for receiving the light focused thereon by the lens means including an array of light sensitive elements; and

d. control means operatively interconnected to the image detector means for receiving signals from the image detector means representative of the light intensity to which the light sensitive elements of the image detector means are exposed and for creating a digitized image of the meter faceplate based on the signals received from the image detector means, said control means further including storage means for storing the digitized image of the meter faceplate, said control means including shutter means for controlling the exposure of the image detector means to the reflected light.

20. An apparatus in accordance with claim 19, wherein said control means further includes pattern recognition means for interpreting the meter readout represented by the digitized image stored in the storage means, the control means being operatively interconnected to transmission means for transmitting the digitized image to a remote location.