Abstract:
The present invention discloses a wireless terminal for checking the amount used of gauge and a gauge management system using a wireless communication network which checks the amount used of electricity, tap water, and gas by a wireless terminal. A wireless terminal established in a front of gauge, senses image of a figure at gauge, transmit data of the amount used with a wireless communication network. So, management of collecting rates of electricity, tap water, and gas are achieved easily.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a wireless terminal for reading meters and a meter-reading management system using wireless communication networks, and more particularly to the wireless terminal for reading the meter by sensing image data displayed on the meter and transmitting the data through a wireless communication network in a bi-directional manner and the meter-reading management system using wireless communication networks in which image on the meter representing the amount consumed for electricity, tap water, or gas is sensed by the wireless terminal and then is transmitted to a central station system so as to manage each individual charges for the amount consumed for electricity, tap water, or gas using a billing management system connected to the central station system.  
         BACKGROUND OF THE INVENTION  
         [0002]    Conventionally, the amount consumed for electricity, tap water, or gas is measured by manually reading the meters settled in each accommodation including houses or buildings by meter-readers, converted into the corresponding rates to be charged in a respective office, and billed to each individual house or building.  
           [0003]    It is general that meter-readings for such amount displayed on the meters are conducted by meter-readers, who visit each place of the meter and writes it down on a check board after read it by a sight. Therefore, the conventional method for meter-reading works has several problems such that it needs many human resources, and has an inefficiency as well as an inaccuracy due to manual records.  
         DETAILED DESCRIPTION OF THE INVENTION  
         [0004]    It is an object of the present invention to remotely manage the meter-reading works for the amount of electricity, tap water, or gas consumed for each accommodation by detecting images displayed on each meter to convert them into digital data, transmitting them to a remote billing management system, and calculating the rates to be charged at the remote billing management system.  
           [0005]    It is another object of the present invention to substantially implement a remote meter-reading management using a wireless communication network just by installing the wireless terminal for sensing the image on the meter showing the consumed amount of electricity, tap water, or gas, without modifying the meters previously mounted.  
           [0006]    It is still another object of the present invention to substantially implement a remote real-time inspection for the state of the wireless terminal or the meter by occasionally calling it through a wireless communication network.  
           [0007]    It is still another object of the present invention to implement an efficient maintenance of the wireless terminal by detecting power-off state of the wireless terminal, notifying it to a control host through a wireless communication network, and simultaneously supplying supplemental power from a auxiliary battery.  
           [0008]    In order to accomplish the aforementioned objects, the present invention may have a wireless terminal for meter-reading, comprising a jointing member formed on the base of a case for combining the wireless terminal with a meter; a power supply section for supplying power to each component; a data transceiver section for receiving meter-reading command and transmitting the read data by communicating with a wireless communication network in a bi-directional manner; a slave controller for decoding/encoding the data to/from the transceiver section; an image sensor for generating digital information about the amount of the meter by sensing the image on the meter and compressing the sensed data; a memory for storing temporary data or a program for operation; a master controller for controlling the data transceiver section, for driving the image sensor in response to the meter-reading command decoded by the slave controller, and for controlling the digital information of the consumed amount provided from the image sensor to be temporarily stored in the memory and to be output after encoded by the slave controller.  
           [0009]    Herein, the power supply section may be constituted so as to supply DC power to each component by using AC power source or a rechargeable battery, or may comprise a circuit for detecting power failures or abnormal state of the battery.  
           [0010]    In addition, the image sensor may be constituted so as to carry out the first compression for composing image data with a bit of data representing bright and dark states by pixels, the second compression for reducing the size of the image by determining and eliminating unnecessary regions, and the third compression for converting the image data into binary data corresponding to decimal numbers.  
           [0011]    A meter-reading management system using a wireless communication network according to the present invention may comprise: the wireless communication network; a central station system for sending a meter-reading command and for receiving the read data; a billing management system for calculating the rate to be charged according to the read data received from the central station system; and a wireless terminal, including a jointing member formed on the base of a case to combine the wireless terminal with the meter, and is constituted so as to image-sense the consumed amount on the meter in response to the meter-reading command supplied through the wireless communication network, to generate the meter-reading data in accordance with the image sensing, and to send the meter-reading data through the wireless communication network. 
       
    
    
     PREFERRED EMBODIMENTS  
       [0012]    Referring to FIG. 1 showing a preferred embodiment according to the present invention, a central station system  12  is connected to a wireless communication network  10  by way of one of the base stations (not shown), wherein the wireless communication system comprises wireless provisions such as base stations, radio towers, and so on (not shown), to assist a bi-directional communication between the central station system  12  and a wireless terminal  16  for transmitting the meter-reading data.  
         [0013]    The central station system  12  can be associated with a number of sub-systems such as a voice mailing system (VMS; not shown) for managing voice mails, a service management system (SMS; not shown) for performing a service for a remote control and a process for call data, an internet gateway system(IGS; not shown) for processing web mail messages, and a billing management system(BMS)  18 , in order to totally control the connections between the wireless communication system  10  and the sub-systems. For example, only the billing management system  18  may be assigned to the central station system  12  as shown in FIG. 1.  
         [0014]    [0014]FIG. 1 shows the meter  14  is installed on each accommodation such as a house or a building in order to measure the amount consumed for tap water, electricity or gas, and the wireless terminal  16  is installed on the meters.  
         [0015]    The wireless terminal  16  image-senses a measured value (e.g., “00583 kwh” for electricity), converts it into data, and then transmits it to the central station system  12  through the wireless communication network  10 . For those functions, the wireless terminal  16  has a easily removable/installable configuration to perform an image sensing by covering a whole surface of the meter  14  as shown in FIG. 2, while has the internal block diagram for the image sensing and data transmission as shown in FIG. 3.  
         [0016]    Generally, the meter  14  has a panel exposed to person&#39;s sight in order to allow us to see the metered value, and the wireless terminal  16  can be constituted to cover a top face of the meter  14  in order to sense the image displayed on the panel.  
         [0017]    That is, as shown in FIG. 2, the wireless terminal  16  comprises a combination of a base  20  and a case  24 . The base  20  has a fixing board perpendicular to both ends of the longitudinal side facing the meter  14 . The case  24  is composed of a window  26 , a solar panel  28 , and an antenna  30 . Here, the window  26  may be made of transparent glass or compound resin so as to allow us to read the values on the meter  14 , or be constituted to display a digitized value which is being read by a image sensor. While the solar panel  28  for supplying an operational power by gathering external light may be constituted, another power source for the wireless terminal  16  can be prepared by using a battery instead of the solar panel  28 . Further, another method for supplying power can be constituted by adopting all of the above two method in parallel, or by extracting a power line supplied to the meter  14 .  
         [0018]    Hereafter, the internal configuration of the wireless terminal  16  will be described referring to FIG. 3.  
         [0019]    The wireless terminal  16  has a power supply section  40  for supplying power into each component. The power supply section  40 , as aforementioned, may be formed to supply DC power by using the current generated by the light-gathering of the solar panel  28 , by using a battery, or by converting AC power supplied to the meter  14  into DC power. It would be appreciated by those skilled in the art that modification or variation for those configuration of the power supply section  40  can be employed in various manner in order to supply DC power to each component in accordance with appropriate intentions by a manufacturer.  
         [0020]    The wireless terminal  16  comprises a master controller  42 , a data transceiver section  44 , a slave controller  46 , an image sensor  48 , and a memory  50 .  
         [0021]    Here, the data transceiver section  44  is constituted to perform bi-directional transmitting/receiving operations through the wireless communication network  10  by controlling the master controller  42 .  
         [0022]    The slave controller  46  is constituted to process the data to transmit/receive it to/from the data transceiver  44 , and the received/transferred data are output/input to/from the master controller  42 .  
         [0023]    The image sensor  48  comprises a pixel array (not shown) for sensing the image on the meter  14  by converting the optical data into analogue electrical signal and a analogue-digital converter (not shown) for converting the analogue signal into a digital signal and for outputting a compressed digital signal to the master controller  42 .  
         [0024]    The memory  50  is constituted so as to store a program for controlling operations and temporary data for processing the image, by controlling the master controller  42 .  
         [0025]    The master controller  42  is constituted to control all operations of each component, such as image-sensing, data transmitting, and data receiving.  
         [0026]    Here, the data transceiver section  44  includes a data transmission circuit and a data receipt circuit, and the data receipt circuit is constituted as shown in FIG. 4 while the data transmission circuit is constituted as shown in FIG. 5.  
         [0027]    As shown in FIG. 4, the data receipt circuit belonging to the data transceiver section  44  is constituted to filter a signal containing minute current values received through the antenna  52  through a filter  56  by way of an amplifier  54 . Here, as a signal with a frequency of 300 MHz is introduced therein, the filter  56  passes a corresponding bandwidth through a saw filter as a band pass filter while blocks other bandwidths. Thus, a signal located in a specific bandwidth is applied to a mixer  58 .  
         [0028]    The mixer  58  is constituted to output an intermediate frequency signal to an amplifier  60 , and a demodulator  62  is constituted to demodulate the intermediate frequency signal amplified by the amplifier  60  into a digital signal and to output a final signal to the slave controller  46 .  
         [0029]    At this time, the mixer  58  receives a mixing signal to eliminate a carrier and to output the intermediate frequency signal. The mixing signal is generated by a receiver phase locked loop (Rx PLL)  64 , a VCO  66 , and a multiplier  68 , and then provided to the mixer  58 . Here, the Rx PLL  64  is controlled by a control signal MCA of the master controller  42 .  
         [0030]    Meanwhile, the data transmitting circuit included in the data transceiver section  44  comprises transmitter phase locked loop (Tx PLL)  70  for generating a carrier signal by applying the control signal MCB from the master controller  42 , and is constituted to allow the carrier signal and the meter-reading data encoded by the slave controller  46  to be applied to a VCO  72 . An input terminal of the VCO  72  preferably comprises a varacter device for determining a modulation width of the data for transmission. The VCO  72  is constituted to generate a signal by modulating meter-reading data to the carrier signal, and the multiplier  74  is constituted to convert an output signal of the VCO  72  into a signal having the frequency multiplied by 3(about 900 MHz). The multiplier  74  is constituted to output a multiplied signal to an amplifier  76 , and a band pass filter  78  is constituted to suppress the noises included in an amplified signal and the signals belonging to an undesirable bandwidth. A power amplifier  80  is constituted to amplify the strength of the signal power enough to finally arrive at a relay station and then to transmit it through the antenna  82 .  
         [0031]    The wireless terminal constituted as aforementioned may be associated with a reflection box  94  shown in FIG. 6, in order to accord the position of the panel of the meter  14  to the position where the image sensor  48  is fixed because it is occasional to happen a misalignment between two positions.  
         [0032]    The reflection box  94  includes an inlet into which an image enters, an outlet from which the image is applied to the image sensor, and a reflection path to transfer the image from the inlet to the outlet. An entrance mirror  94  is installed at the inlet with a predetermined angle so as to reflect the image in parallel along the path, and an exit mirror is installed at the outlet with a predetermined angle so as to reflect the image transferred through the reflection path. Between the exit mirror  96  and the image sensor  102 , a lens  98  can be interposed. The lens  98  focuses the image reflected from the exit mirror  96  on the image sensor  102 . Additionally, in order to obtain constant illumination of the image on the sensor ( 102 ), a lamp  100  may be preferably installed between the image sensor  102  and the lens  98  of the outlet.  
         [0033]    By constituting the embodiment of a meter-reading management system with a wireless communication network according to the present invention as aforementioned, it is possible to accomplish a meter-reading using the wireless terminal  16 .  
         [0034]    The meter-reading using the wireless terminal  16  can be started by the master controller&#39;s  42  receiving the meter-reading command from the central station system  12 .  
         [0035]    The central station system  12  searches current calls and maintains synchronization with that, and then demands a point call to confirm a location of the wireless terminal  16 . If the wireless terminal  16  performs a channel assignment to response the location confirmation, the central station system  12  determines whether or nor the assigned channel is BUSY, and transfers the determination result to the wireless terminal  16 . The wireless terminal  16  transfers a response in order to register its location to the central station system  12 , and the central station system  12  transfers the meter-reading command through the call channel.  
         [0036]    According to aforementioned operations, when the meter-reading command is transmitted from the central station system  12 , the master controller  42  receives the meter-reading command which is amplified, filtered, intermediate-frequency mixed, and demodulated by the data receipt circuit in FIG. 3 belonging to the data transceiver section  44 .  
         [0037]    Subsequently, the master controller  42  controls the image sensor  48  to read the consumed amount displayed on the panel of the meter  14 . Further, the data sensed by the image sensor  48  is compressed and then stored in the memory  50 .  
         [0038]    Specifically, if the decimal number displayed on the panel of the meter  14  is “00583”, the image sensor  48  reads the numbers one by one.  
         [0039]    That is, the numbers are read in the order of “0”, “0”, “5”, “8”, and “3”.  
         [0040]    As a result, each numerical value read from the panel of the meter  14  covers a wide area as shown in FIG. 7 a.  At this time, the first data compression is carried out.  
         [0041]    Specifically, the image sensor  48  has a constant number of pixels (e.g., 300×400), and converts the light signal received in the form of different levels into an analogue electrical signal in accordance with the light incident on each optical-electronic means(not shown) pixel by pixel. In addition, the analogue electrical signal is converted into a digital signal representing “0” or “1” by an analogue-digital converter employed in the image sensor  48  in accordance with the brightness.  
         [0042]    While a common image sensor process the brightness data with 256 gradients in the form of 8-bit data, the present image sensor  48  further compresses the 8-bit data to 1-bit data. Thus, the image sensor  48  obtains first-compressed image data with the capacity of 15 Kbyte which is one-eighth of the 120 Kbyte generated in the form of 8-bit data by pixel.  
         [0043]    However, the 15 Kbyte is still too much to be treated in the environment of wireless communication. Therefore, the size of the image is shrunken to the necessary area to identify a character by the analogue-digital converter employed in the image sensor  48 , and the image of FIG. 7 a  is reduced to that of FIG. 7 b.  That is, the second compression for the image data is to eliminate unnecessary areas.  
         [0044]    For the above second compression, the image-sensed area is divided by X- and Y-axes to allow each pixel to have the position value in the coordinate system, and then unnecessary areas where there is no character data sensed are removed to a maximum.  
         [0045]    As the size of the image data is still large even after completing the second compression, the analogue-digital converter of the image sensor  48  conducts the third compression by means of a statistical feature extraction as one of the pattern recognition method as shown in FIGS. 7 c  through  7   e.    
         [0046]    For example, as shown in FIG. 7 c,  an image can be segmented into the same areas with rows and columns, and the number of black pixels for each area is evaluated. Accordingly, assuming that an image is divided into 8-row×8 -column, the image can be abstracted to a vector of 64 dimensions.  
         [0047]    For another example, as shown in FIG. 7 d,  the features of the image can be extracted by scanning in the directions of row and column in the manner of circumferential feature extraction. That is, the run length of white pixels is calculated until the first black pixel meets for each scanning line, and the calculated run lengths are accumulated and normalized.  
         [0048]    For still another example, as shown in FIG. 7 e,  features of the character can be recognized in the manner of cross-number feature extraction in which the number of cross is scanned and accumulated along several vertical lines, the accumulated values are normalized by the number of scanning lines, and, particularly, features on the upper and lower intersections is extracted by scanning along the horizontal direction not the vertical direction.  
         [0049]    Besides the methods shown in FIGS. 7 c  through  7   e,  it is available to adopt another methods for extracting features such as contour length method, pixel connection method, or Fourier analysis method.  
         [0050]    The data obtained from the method shown in FIGS. 7 c  through  7   e  is compared with a reference data stored previously. If the obtained data is similar to the reference data 90 through 95 percentages or over, the obtained data is regarded as a valid data. Provided comparison result corresponds to a value “8”, the image data is converted into a 4-bit binary data that is “1000” corresponding to the decimal data “8”. Thus, the image sensor  48  provides the binary data “1000”to the master controller  42  when a numerical value on the meter  14  is “8”, and then the master controller  42  makes the binary data be stored in the memory  50 .  
         [0051]    As aforementioned, if the consumed amount of the meter  14  is identified by performing the operations of image-sensing, compressing, and storing the data, the master controller  42  transmits the read data to the slave controller  46  which provides an encoded meter-reading data to the data transceiver section  44 .  
         [0052]    Subsequently, the data transceiver section  44  mixes the read data with a carrier generated from the transmitter PLL  70  in response to the control signal MCB of the master controller, and transmits the data signal amplified and filtered from the mixed signal through the antenna  82 .  
         [0053]    The data received by the antenna  82  through the wireless communication network  10  is applied to central station system  12 , which delivers the received data to the billing management system  18  and sends the message informing of a safe receipt of data to the wireless terminal  16 . After the wireless terminal  16  transmits the read data, it waits to receive the safe receipt message, and returns to the stand-by mode as soon as receives the safe receipt message. Meanwhile, the billing management system  18  calculates and manages the rate to be charged for each meter-reading data arrived thereat.  
         [0054]    It would be appreciated by those skilled in the art that the aforementioned preferred embodiments can be varied or modified to employ various kinds of image sensing method, e.g., scanner method, photographing method, motion detection method using a timer, or roller method.  
         [0055]    In addition, through an electronic mail of an on-line method as well as a postal service of an off-line method, a notice of charges for the amount consumed for electricity, tap water, or gas can be issued by the billing management system  18  using various kinds of systems associated with the central station system  12  as subsystems.  
         [0056]    In the meantime, as shown in FIG. 8, it is possible to include a relay station  110  between the wireless communication network  10  and the wireless terminals  16 , which is applicable to the environment that a home-LAN or Bluetooth integrates and controls a plurality of the wireless terminal  16  for measuring the amount consumed for electricity, tap water, and gas, through the relay station  110 .  
         [0057]    According to another embodiment of the present invention, additional circuits for coping with power-off failure can be included between the master controller and the power supply section as shown in FIG. 9.  
         [0058]    [0058]FIG. 9 shows the embodiment that an adapter supplies power, wherein a central controller  206  corresponds to the master controller in FIG. 3 and the others corresponds to the power supply section in FIG. 3. VBB is a rechargeable battery.  
         [0059]    In detail, it comprises a DC power supply  200  for converting AC power of 220V into DC power of 5V, including a rectifier (not shown) for converting AC to DC, a transformer(not shown) for modifying a voltage level, and a smoothing circuit(not shown) for smoothing a signal wave. A regulator  202  is constituted to convert the output of the DC power supply  200  into a voltage of 3.3V that substantially required by the wireless terminal, and two outputs from the regulator  220  are applied to 2 input terminals IN 1  and IN 2  of an OR gate  204 .  
         [0060]    The OR gate  204  is constituted to provide a voltage of a high level to the central controller  206  when either one of 2 input terminals IN 1  or IN 2  is high.  
         [0061]    Meanwhile, the output of the regulator  202  which is applied to the input terminal IN 1  of the OR gate  204  is connected to the rechargeable battery VBB through a resistor R 1  connected to the output in parallel, and a resistor R 2  and a diode D 1  which are connected from each other in parallel. The rechargeable battery VBB is charged by the current passing through the path from the output of the regulator  202 . The voltage applied to the resistor R 1  is also provided to a port P 1  of the central controller  206  and thereby the central controller  206  detects power failure. The resistor R 1  also has a function to prevent an inflow of excess current.  
         [0062]    In addition, a resistor R 3  is connected to a port P 1  of the central controller  206  in order to sense the current supplied to the rechargeable battery VBB, and a resistor R 4  is connected to the resistor R 3  in parallel. The resistor R 4  is connected to a regulator  208  which provides a DC voltage of 3.3V to the input terminal IN 2  of the OR gate  204  by the rechargeable battery VBB. The central controller  206  detects a charge status of the rechargeable battery VBB through the port P 1 , and the resistor R 3  also has a function to prevent an inflow of excess current. The resistor R 4  stabilizes a voltage level supplied to the regulator  208 , and prevents damages of the central controller  206  and the regulator  208  by dividing current when the rechargeable battery fails or the circuits are shorted.  
         [0063]    According to the aforementioned constitution of a power supply, when a power is normally supplied from the DC power supply in a stable state, voltage of high levels is applied to the input terminals IN 1  or IN 2  of the OR gate  204 , and the rechargeable battery VBB is charged by the current passing through the path of the resistors R 1  and R 2 , and the diode D 1 . Therefore, as the high-level voltages are applied to the input terminal IN 1  or IN 2  of the OR gate  204 , a high-level voltage for operating the central controller  206  can be supplied.  
         [0064]    By the contrary, if power failure occurs, the regulator  202  applies low-level voltages to the input terminals IN 1  or IN 2  of the OR gate  204 . However, as a high-level voltage is applied to the input terminal IN 2  of the OR gate  204  from the regulator  208  by the rechargeable battery VBB, the OR gate  204  supplies a high-level voltage to operate the central controller  206 .  
         [0065]    On the other hand, if the central controller  206  detects a presence of a power failure by sensing a signal applied to the port P 2 , the central controller  206  outputs the power failure information signal as a signal TD, which is transferred to the central station system through the data transceiver section after encoded by the slave controller.  
         [0066]    Further, if the central controller  206  detects an abnormal state in charging and operating the rechargeable battery by sensing a signal applied to the port P 1 , the central controller  206  outputs the abnormal battery status information signal as a signal TD, which is transferred to the central station system through the transceiver section after encoded by the slave controller.  
         [0067]    As described above, by employing the circuit shown in FIG. 9, it is possible to operate the wireless terminal with a stable state even during a power failure. By transmitting information about a power failure or an abnormal battery condition to the central station system through a wireless communication, it is possible to totally manage operational status of the wireless terminals.  
         [0068]    Regarding the current consumed in transmitting and receiving data, it is preferable to adopt the rechargeable battery with a high capacity.  
         [0069]    Industrial Availability  
         [0070]    According to the present invention, since there is no need to visit each accommodation to check out the amount consumed for electricity, tap water, and gas, it is possible to reduce human resources for meter-reading works.  
         [0071]    Further, since existing manual meter-reading works can be substituted with a remote management using image sensing, it is possible to enhance work performance and to ensure reliability of the data.  
         [0072]    Moreover, since easily installable/removable wireless terminal can be employed, it is possible to use existing meters without modifications.  
         [0073]    Moreover, since the current status of the meters such as power failure or an abnormal battery condition can be remotely detected, it is possible to ensure efficiency of the system maintenance.