Abstract:
A utility meter endpoint measures consumption of a commodity such as water, gas, or electricity, includes a configurable function for detecting the presence of an abnormality in consumption such as leaks, tampering, short-circuits or other malfunctions, or unauthorized bypassing of the meter, and the like. The endpoint can take multiple samples according to a configurable time schedule, and test the usage pattern against programmable criteria that reflect certain types of unusual activity or other problems. If the criteria are satisfied, the endpoint can report the occurrence of the unusual event to the AMR system during its usual communications cycle or by initiating a special, unscheduled communication to signal an alarm condition.

Description:
RELATED APPLICATIONS  
       [0001]     This application claims priority to U.S. provisional application 60/728,643, filed Oct. 20, 2005, the disclosure of which is incorporated by reference herein in its entirety. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The invention relates generally to metering of utility consumption, and more particularly, to detecting unusual consumption patterns.  
       BACKGROUND OF THE INVENTION  
       [0003]     Automatic meter reading (AMR) systems are generally known in the art. Utility companies, for example, use AMR systems to read and monitor customer meters remotely, typically using radio frequency (RF) communication. AMR systems are favored by utility companies and others who use them because they increase the efficiency and accuracy of collecting readings and managing customer billing. For example, utilizing an AMR system for the monthly reading of residential gas, electric, or water meters eliminates the need for a utility employee to physically enter each residence or business where a meter is located to transcribe a meter reading by hand.  
         [0004]     There are several different ways in which current AMR systems are configured. In a fixed network, endpoint devices at meter locations communicate with readers that collect readings and data using RF communication. There may be multiple fixed intermediate readers, or relays, located throughout a larger geographic area on utility poles, for example, with each endpoint device associated with a particular reader and each reader in turn communicating with a central system. Other fixed systems utilize only one central reader with which all endpoint devices communicate. In a mobile environment, a handheld unit or otherwise mobile reader with RF communication capabilities is used to collect data from endpoint devices as the mobile reader is moved from place to place.  
         [0005]     AMR systems generally include one-way, one-and-a-half-way, or two-way communications capabilities. In a one-way system, an endpoint device periodically turns on, or “bubbles up,” to send data to a receiver. One-and-a-half-way AMR systems include receivers that send wake-up signals to endpoint devices that in turn respond with readings. Two-way systems enable command and control between the endpoint device and a receiver/transmitter as well as to data transmission by the endpoint device.  
         [0006]     In addition to reporting consumption information, there is a need for endpoint devices to indicate alerts to the utility provider when unusual or suspicious activity is detected. Tamper and malfunction detection systems incorporated in utility meters are generally known in the art. These include mechanical, electromechanical, optical, and electronic systems, such as those described in U.S. Pat. Nos. 3,893,586; 4,588,949; 4,665,359; 4,811,600; 5,025,470; 5,086,292; 5,113,130; 5,148,101; 5,293,115; 5,422,565; 5,473,322; 6,098,456; and 6,236,197.  
         [0007]     Although the aforementioned event detection systems can indicate unusual conditions occurring with the meter or endpoint, these systems are not designed to recognize unusual consumption patterns that are indicative of problems or misuse such as leaks or bypassing of the meter by the customer when the meter or endpoint device itself has not been directly tampered with.  
         [0008]     Analysis of metered data collected at the central station can indicate long-term average usage trends, but the collected consumption data typically is not sampled and collected sufficiently frequently to enable extraction of the necessary short-term patterns such as abrupt but temporary changes in consumption. For example, conventionally-collected meter readings do not distinguish between consumption patterns during the day versus during the night. Increasing the meter reading frequency is often impractical due to limitations in the AMR system communications channel capacity. Furthermore, because endpoint devices are typically battery-powered and because of traffic limits on the number and frequency of transmissions, it is not desirable to significantly increase the number of radio transmission of information.  
       SUMMARY OF THE INVENTION  
       [0009]     One aspect of the invention is directed to a utility meter endpoint that measures consumption of a commodity such as water, gas, or electricity, includes a configurable function for detecting the presence of an abnormality in consumption. Such abnormalities include, but are not limited to, leaks, tampering, short-circuits or other malfunctions, or unauthorized bypassing of the meter, and the like. Preferably, in response to detecting an abnormality, the endpoint device provides an indication to that effect via an automatic meter reading (AMR) system to a reader or data receiving station.  
         [0010]     Instead of having to transmit the meter readings more frequently to detect usage patterns or short-term changes in consumption, a utility meter endpoint according to one embodiment of the invention takes multiple samples according to a configurable time schedule, and tests the usage pattern against programmable criteria that reflect certain types of unusual activity or other problems. If the criteria are satisfied, the endpoint can report to the AMR system during its usual communications cycle that it has detected an unusual event. Alternatively, the endpoint can initiate a special, unscheduled communication to signal an alarm condition.  
         [0011]     In one embodiment, utility providers can define the programmable criteria based on a set of parameters such as: one or more consumption rate thresholds, number of occurrences of threshold events in a defined time period, duration of sampling of consumption, and frequency of sampling. Different types of meters and installations can be associated with corresponding default parameter settings. For example, single family dwellings, multi-family dwellings, commercial sites, light industrial, and heavy industrial installations can each have a different set of parameter settings.  
         [0012]     In a related embodiment, the endpoint device can be programmed to automatically learn each customer&#39;s established usage pattern, and identify suspicious deviations from the established pattern. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which:  
         [0014]      FIG. 1  is an exemplary diagram of a coverage cell of a fixed AMR system in accordance with an embodiment of the invention.  
         [0015]      FIG. 2  is a diagram illustrating an example embodiment of a utility meter endpoint adapted to communicate wirelessly with an AMR system.  
         [0016]      FIG. 3  is a flow diagram illustrating one method of detecting an unusual consumption pattern by an endpoint according to one aspect of the invention. 
     
    
       [0017]     While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0018]     Endpoints and AMR communication modes AMR system  100 , as depicted in  FIG. 1 , that utilizes the invention includes at least one utility measurement device including, but not limited to, electric meters  102 , gas meters  104  and water meters  106 . Each of the meters may be either electrically or battery powered. The system further includes at least one endpoint  108 , wherein each corresponds and interfaces to a meter. Each of the endpoints  108  preferably incorporates a radio frequency (RF) device, e.g., the Itron®, Inc. ERT as described in detail, for example, in U.S. Pat. Nos. 5,056,107; 6,262,685; and 6,934,316, the disclosures of which are hereby incorporated by reference. The system additionally includes one or more readers that may be fixed or mobile,  FIG. 1  depicts: (1) a mobile hand-held reader  110 , such as that used in the Itron Off-site meter reading system; (2) a mobile vehicle-equipped reader  112 , such as that used in the Itron Mobile AMR system; (3) a fixed radio communication network  114 , such as the Itron Fixed Network AMR system that utilizes the additional components of cell central control units (CCUs) and network control nodes (NCNs); and (4) a fixed micro-network system, such as the Itron MicroNetwork™ AMR system that utilizes both radio communication through concentrators and telephone communications through PSTN. The disclosure of the various patents and technical publications describing these systems are hereby incorporated by reference. Of course other types of endpoint devices, readers and AMR networks may be used without departing from the spirit or scope of the invention. Further included in AMR system  100  is a head-end, host processor  118  that incorporates software that manages the collection of metering data and facilitates the transfer of that data to a utility or supplier billing system  120 .  
         [0019]     Data collected by the endpoints  108  can be read via the AMR system by mobile readers  110 ,  112 , or fixed radio communication network  114 . Alternatively, data can be read and re-transmitted by the AMR system via an intermediate transmitter/receiver that extends the range of communication between a reader and endpoints  108 . Regardless of how the endpoint data is read, in one embodiment a reader may include a transmitter, a receiver, an input component and a data storage component.  
         [0020]     In AMR system  100 , endpoints  108  can support one-way meter reading, 1.5-way meter reading, or two-way meter reading systems. In a one-way meter reading system, the reader listens to messages sent asynchronously from each endpoint. In such a system, endpoints do not need to receive any information from the reader. In a two-way meter reading system, endpoints listen for, and respond to prompting signals issued by the reader. Prompting signaling may include requests for utility meter consumption data, information about the endpoint&#39;s operational status or configuration settings, information about events that might have occurred (such as any outages), instructions to modify specified operating parameters, or the like. Therefore, a two-way meter reading system facilitates the AMR system reader&#39;s communicating with and optionally commanding the endpoint, while also facilitating the endpoint&#39;s responding to the reader&#39;s communications and commands. A 1.5-way meter reading system facilitates prompting endpoints to request data transmission by the endpoints, but avoids the additional complexity of command and control communications of two-way systems. In a 1.5-way system, the reader sends prompting signals to endpoints, which, in turn, listen for, and respond to the prompting signals by simply transmitting their collected data.  
         [0021]      FIG. 2  illustrates one exemplary embodiment of a utility meter endpoint  208 . Endpoint  208  interfaces with a utility meter  210 , receives consumption, utility meter status, history, and other such relevant data from utility meter  210 , and communicates the data to AMR system  212 . Endpoint  208  includes an interface system  214 , which operatively couples to utility meter  210  via coupling  215 . In one embodiment, coupling  215  includes electrical and mechanical components for making a physical and electrical connection between utility meter  210  and endpoint  208 . For example, coupling  215  can include electrical connectors and conductors that carry electrical signals from utility meter  210  to interface hardware in interface system  208  that converts the electrical signals into a digital representation that is readable by a microprocessor or microcontroller  216 . Interface system  214  is, itself, interfaced with microprocessor  216  via interface  215 . In one embodiment, interface  215  includes a portion of a data bus and of an address bus. Alternatively, interface  215  may comprise a serial communication link.  
         [0022]     Microprocessor  216  is a controller that oversees operation of endpoint  208 . In one embodiment, microprocessor  216  includes a microprocessor system that has memory, instruction processing, and input/output circuits. Microprocessor  216  interfaces with radio transceiver  218  via interface  217 . In one embodiment, interface  217  includes a portion of a data bus and of an address bus, which is coupled to an antenna  220 . Alternatively, interface  217  may comprise a serial communication channel. In operation, interface hardware  214  forwards and converts utility meter data to microprocessor  216 . Microprocessor  216  processes, and stores the data at least temporarily, and instructs transceiver  218  to communicate the data to AMR system  212  at appropriate or preprogrammed/predefined times.  
         [0023]     In one embodiment, endpoint  208  operates in a low-power standby mode during a majority (&gt;50%) of the time. While in the standby mode, interface system  214 , microprocessor  216 , and transceiver  218  are effectively shut down so that they consume at most a negligible amount of power. Timer  222  operates to periodically wake up the shut-down systems so that they enter into an active operating mode. In one embodiment, timer  222  is an independent circuit that is interfaced with microprocessor  216 . In another embodiment, timer  222  is implemented as a watchdog timer in a microcontroller that is a part of microprocessor  216 . In either embodiment, one feature of timer  222  is that timer  222  consumes relatively little energy for operating. Also, upon expiration of a time duration set into timer  222 , timer  222  provides a signal that initiates bringing online the systems that are in standby mode. In a related embodiment, the settable time duration is set in timer  222  by microprocessor  216  via setup signal  223 . For example, setup signal  223  can be carried via a data bus or other communication channel.  
         [0024]     According to one example embodiment, endpoint  208  includes a power supply  224 . In this embodiment, power supply  224  includes one or more batteries. Power supply  224  provides conditioned power to interface system  214 , microprocessor  216 , and transceiver  218  via switchable power bus  225 . Power supply  224  provides conditioned power to timer  222  via power line  226 . Timer  222  provides a control signal  228  to power supply  224  that causes power supply  224  to apply power to power bus  225 . Microprocessor  216  provides a control signal  230  to power supply  224  that causes power supply  224  to remove power from power bus  225 . In operation, beginning in a standby mode, timer  222  has been configured with a set time duration by microprocessor  216  via setup signal  223 . Timer  222  monitors the passing of the time duration and, at the expiration of the time duration, timer  222  provides a signal to power supply  224  to energize power bus  225 . Once power is applied via power bus  225  to microprocessor  216 , interface system  214 , and transceiver  218 , microprocessor  216  begins executing a program instructions or code that gathers data from utility meter  210  via interface system  214 , and momentarily activates transceiver  218 . Once the program is complete, microprocessor  216  sets a time duration into timer  222  and initiates timing, and generates control signal  230  to power down the systems that have been powered via power bus  225 .  
         [0025]     The momentary operation cycle described above is one example of endpoint activity in response to a bubble-up event. A bubble-up event is herein defined as a condition to which an endpoint responds by exiting a low-power standby operating mode or state, and enters a more active operating mode or state for the purpose of gathering data and/or engaging in data communications. One example of a bubble-up event is the passage of a predefined period of time since the previous bubble-up event. Another example of a bubble-up event is an occurrence of a predefined date and time at which a communication cycle has been scheduled to take place. In one example embodiment of endpoint  208 , in response to a bubble-up event, transceiver  218  operates in a one-way communications mode, in which it simply transmits the utility meter data via RF communication  221 . To support this example one-way communication, the reader operates continuously in a mode receptive to transmissions by endpoints. Depending on its programmed operating mode, endpoint  208  can respond to a bubble-up event by gathering and processing meter data for later transmission in response to a future bubble-up event.  
         [0026]     Two-way and 1.5-way endpoints can also communicatively respond to bubble-up events by entering into a temporary receptive operating mode for a predefined duration of time. For example, in one embodiment, if transceiver  218  detects any incoming communications via the AMR system during the time duration, transceiver  218  signals microprocessor  216 . Microprocessor  216  then determines whether to respond to the received signal. In one embodiment of a two-way endpoint, microprocessor  216  is programmed to listen for further instructions from AMR system  212  when microprocessor  216  determines that communications have been directed at endpoint  208 . The further instructions could request particular information such as utility meter consumption data transmission from endpoint  208 , in which case endpoint  208  will transmit such data. Alternatively, the further instructions could request a configuration change in endpoint  208 , in which case microprocessor  216  will institute the requested change if such a change is permitted. In this example embodiment, AMR system  212  can communicate any number of instructions, such as configuration changes, requests for data transmission, or the like, to endpoint  208 . In turn, endpoint  208  responds to any such received instructions according to its operating program.  
         [0027]     In one embodiment of a 1.5-way endpoint, microprocessor  216  is programmed to cause the endpoint  208  to transmit a predefined set of data, such as, for example, utility consumption data, during a specified time slot in response to a received signal determined to be directed to the endpoint. In this manner, the example 1.5-way endpoint avoids the extra processing, receiving, and associated energy consumption needed to support a two-way communication protocol.  
         [0028]     In one embodiment, endpoint  208  can voluntarily initiate transmission of additional information that was not requested or expected by AMR system  212 . For example, endpoint  208  can transmit alarm information such as in response to a detected tampering event or to a suspicious change in utility consumption. Such information can be transmitted during a scheduled bubble-up event, or spontaneously, depending on the urgency or priority of the information.  
         [0000]     Detection of Unusual Consumption Activity  
         [0029]     According to one aspect of the invention, the endpoint is programmed to operate during two types of bubble-up events: data gathering bubble-up events, and data transmission bubble-up events. In data gathering bubble-up events, endpoint  208  powers up to read the utility meter, store the consumption and other information, and conduct further processing of the gathered information. The endpoint does not normally transmit data to the AMR system during this type of bubble-up event. The data processing includes analysis of usage patterns to detect tampering, leaks, malfunctions, suspicious activity, or other abnormalities. Data gathering bubble-up events occur at a frequency that corresponds to the time instances when the meter data is to be sampled. Between bubble-ups, endpoint  208  can remain in a low-power standby state.  
         [0030]     In data transmission bubble-up events, endpoint  208  can perform all of the functions normally performed in data gathering bubble-up events. Additionally, endpoint conducts communications with the AMR system. A data transmission bubble-up event can occur at a scheduled or adjustable interval, for example, to optimize communication reliability in the AMR system, and battery life in endpoint  208 . Additionally, data transmission bubble-up events can occur based upon the happening of an event, such as a detection of unusual consumption activity by endpoint  208 .  
         [0031]      FIG. 3  is a flow diagram illustrating an exemplary routine  300  for detecting unusual consumption events. In one embodiment, steps of routine  300  are performed during data gathering and data transmission bubble-up events. In another embodiment, only a portion of a particular step of routine  300  is performed, depending on the nature of the operations in the step.  
         [0032]     Routine  300  is based on taking samples of utility meter consumption information, determining the amount of consumption occurring during pre-defined intervals, comparing the determined consumption amounts against criteria representing unusual activity, and, if the criteria are satisfied, identifying that an unusual event has been detected. In a preferred embodiment, the sampling intervals and decision criteria are configurable. For example, these parameters can be configured at the factory, or on-site by an installer. In 1.5-way and 2-way AMR systems, the parameters can be remotely configured via AMR communications. In one approach, endpoint  208  conducts heuristic analysis according to a self-learning program to set the configurable parameters based on the history of utility consumption at the specific utility meter installation. In a related embodiment, the self-learning program has configurable parameters, which permits the utility provider to dynamically re-define how endpoint  208  learns.  
         [0033]     According to routine  300 , at  302 , endpoint  208  self-configures, or receives configuration information to define a sampling window, sampling period, problem event criteria, and event count criteria. Table 1 below summarizes these exemplary parameters.  
                             TABLE 1                           Exemplary Configurable Parameters            Parameter   Definition   Example               Sampling window   Time interval for which an   10 minutes           amount of consumption is           computed       Sampling period   Frequency of occurrence of the   1 hour           sampling window       Problem event criteria   An unusual consumption amount   A high or low threshold           (high or low) for a given sampling   such as:           window which, if experienced to a   50 gallons per           sufficient extent (as determined   sampling window;           by the event count criteria), is   &lt;1 CFM per sampling           cause for indicating a presence of   window           unusual consumption activity   Outside the range of 5-25 kWh               per sampling               window between 1:00               A.M. and 5:30 A.M.       Event count criteria   Number of occurrences   24 consecutive           (consecutively or per unit time) of   occurrences           unusual consumption amounts   At least 20           needed to trigger indication of   occurrences out of the           unusual consumption activity   last 24 sampling               periods               50 occurrences               between 8:00 A.M.               and 8:00 P.M. over the               last calendar month                  
 
         [0034]     At step  304 , endpoint  208  pauses until the end of the current sampling period, i.e., until the start of the next sampling period. On startup of routine  300 , the start of the next sampling period can be immediate. In one embodiment, step  304  is executed by scheduling the next bubble-up event to coincide with the start of the next sampling period, and entering the low-power standby mode.  
         [0035]     At  306 , at the beginning of the sampling window, endpoint  208  takes a first meter reading, and stores it. Endpoint  208  can then schedule the next bubble-up event to occur at the time corresponding to the end of the sampling window. At that time, at  308 , endpoint  208  takes a second, reference meter reading. At  310 , the amount of supplied commodity consumed during the sampling window is computed, such as by taking the difference between the first and second meter readings.  
         [0036]     At  312 , endpoint  208  compares the computed difference against the problem event criteria. The comparison can be as simple as subtracting a low threshold from the computed consumption during the sampling window, for example. If, as indicated at  314 , the problem event criteria is not met, the event counter is reset at  316 , and the routine loops back to step  304 . If, on the other hand, the problem criteria are met by the measured consumption during the sampling window, the event occurrence is recorded. In one embodiment, the recording consists of simply incrementing an event counter, as indicated at  318 . Alternatively, actual reading values and/or computed or measured information may be recorded.  
         [0037]     Next, at  320 , endpoint  208  tests whether the records of the event occurrences meet the previously-established event count criteria. If the event count criteria are not met, the routine loops back to  304  to continue gathering sampled data. If the event count criteria have been met, the routine indicates that a positive detection of unusual consumption activity has occurred. In one embodiment, based on the severity of the detected unusual consumption event, endpoint  208  may wait until the next communication time to issue the indication to the AMR system, or may issue an alarm immediately. The routine proceeds to either store a record of the positive detection, or to clear the detection flag, and loop back to  316 .  
         [0038]     The present invention may be embodied in other specific forms without departing from the spirit of the essential attributes thereof, therefore, the illustrated embodiments should be considered in all respects as illustrative and not restrictive.