Patent Document

CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    The present application is related to U.S. patent application Ser. No. __/______ entitled “POSITIVE FLOW METER” filed concurrently with this application and also to U.S. patent application Ser. No.__/______ entitled “DISTRIBUTED RESIDENTAL ALARM SYSTEM AND METHOD THEREFOR” also filed concurrently with this application. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates generally to water control systems, and more specifically, to a system for controlling a household water supply.  
           [0004]    2. Background of the Invention  
           [0005]    Water supplies connected to a household are typically controlled only at the points of service, e.g., sink faucets, shower valves and appliances that connect to the water supply provide individual shut-off for water flow. The household water supply connection is typically controlled by a manual external valve that can be used to shut-off water flow in the event of an emergency water leak or for servicing the water supply system plumbing or replacing appliances.  
           [0006]    Flooding due to plumbing failures is a major source of damage to structures and fixtures such as carpeting, wood flooring, wallboard, etc. The most frequent water supply emergency events are failure due to freezing temperatures inside the water supply plumbing and failure of the water heater tank. A freezing condition usually occurs when the house is unoccupied, for example, a vacation home that is unoccupied during winter is at risk for damage due to bursting of water supply lines due to freezing. Other water supply emergency events may occur when the house is unoccupied, such as failure of a polyvinyl chloride (PVC) plumbing joint, or water heater tank wall erosion and leakage.  
           [0007]    Since water pressure needs to be available while persons are present in the household, the supply pressure must be available when the household is occupied. Also, certain automatic water users such as icemakers, dishwashers and washing machines make automatic demands on the water supply that may occur when the household is unoccupied. It is also inconvenient to manually control a household water supply upon entering or exiting a household.  
           [0008]    Systems have been implemented that shut off the household water supply in response to detection of leaks using detectors located near water heaters, sinks, etc. But, these systems only protect against leaks where water reaches the detectors and could require a large number of detectors for adequate coverage. Other systems have been developed that measure water flow and shut off the water supply if excessive flow occurs based on whether or not the house is occupied as programmed manually by a switch. The flow type systems typically use flow meters that are incapable of detecting water flows below a certain threshold, such as a dripping faucet.  
           [0009]    Therefore, it would be desirable to provide a method and system for controlling a household water supply to prevent flooding. It would further be desirable to control a household water supply in a manner that automatic water users are able to obtain water, while preventing leaks that occur while the water supply is not being used.  
         SUMMARY OF THE INVENTION  
         [0010]    The above objective of preventing flooding due to plumbing failure is achieved in a method and system that automatically control a household water supply. The system includes an electrically controllable valve, a motion sensor and a control system for controlling the automatic valve in conformity with a motion detector output.  
           [0011]    The foregoing and other objectives, features, and advantages of the invention will be apparent from the following, more particular, description of the preferred embodiment of the invention, as illustrated in the accompanying drawings.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    [0012]FIG. 1 is a schematic diagram depicting a household water supply coupled to a system in accordance with an embodiment of the present invention.  
         [0013]    [0013]FIG. 2 is a block diagram depicting a system in accordance with an embodiment of the present invention.  
         [0014]    [0014]FIG. 3 is a pictorial diagram depicting control panel  34  of FIG. 2.  
         [0015]    [0015]FIG. 4 is a flowchart depicting operation a system in accordance with an embodiment of the present invention.  
         [0016]    [0016]FIG. 5 is a flowchart depicting further operation of a system in accordance with an embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]    Referring now to the figures and in particular to FIG. 1, a household water supply coupled to a system in accordance with an embodiment of the present invention is shown. Within household  10 , a cold water supply line  11  routes the water supply to various fixtures such as sinks  14 , a refrigerator  16  containing an ice maker  17  toilets  15 , and so forth. A water heater  12  is also coupled to cold water supply line  11 , to supply a hot water supply line  13 , which is routed to sinks  14  and other fixtures in household  10 . Cold water supply line  11  is also coupled to lawn sprinklers  18  by electrically controlled sprinkler valves  19  that are activated and deactivated by an electric sprinkler control  20  system.  
         [0018]    Water pressure for the entire household  10  water supply system is provided by a water supply main coupling controlled by electrically controllable valve  21 . A control system  30  in accordance with an embodiment of the present invention is electrically coupled to electrically controlled valve  21 , to shut off the water supply to household  10  in the presence of a detected abnormal flow condition. Flow of water into household  10  is detected by flow meter  24  which is generally a positive flow meter as described in co-pending U.S. Patent Application entitled: “POSITIVE FLOW METER”, filed concurrently herewith and the specification of which is incorporated herein by reference. Use of a valve in accordance with the embodiment described in the above-referenced patent application permits the detection of very small flow rates associated with small leaks. As the present invention detects a leak in accordance with starting and stopping of water flow, a valve that can measure a very small continuous flow is exceptionally useful in embodiments of the present invention.  
         [0019]    Within household  10 , are located motion sensors  22 , providing an indication of occupancy of household, and consequently, whether flow through flow meter  24  is normal use by an occupant of household  10 . A motion sensor  22  may also be located near an entrance  23  in addition to or in alternative to locating motion sensors  22  throughout household  10 . If motion sensors  22  are located adjacent to every used entrance  23  of household  23 , occupancy may be determined, but generally not activity of occupants. If motion sensors  22  are located throughout household  10 , the system of the present invention may control water flow in accordance with activity of occupants. Specific embodiments of the present invention may locate motion sensors near zones of use, such as near a shower or bathtub, so that larger flows produced by these fixtures may be correlated with the activity of an occupant.  
         [0020]    Control system  30  derives information from motion sensors  22  and flow meter  24  in order to control the household  10  water supply via electrically controllable valve  21 . Information from other sensors for detecting abnormal conditions may also be provided to control system  30  as well as manual controls and operating controls. Sprinkler control  20  is electrically coupled to control system  30  to provide a signal of normal sprinkler usage.  
         [0021]    Referring now to FIG. 2, details of control circuit  30  and its interconnections are depicted. Control circuit  30  receives motion sensor inputs and sprinkler control inputs, as well as an input from a seismic activity detector  31 , a temperature detector  32  and a control panel  34 . Temperature detector  32  is used to predict potentially freezing conditions within cold water supply line  11  and electrically controllable valve  21  may be shut off in conformity with detecting the potentially freezing condition. Likewise, seismic activity detector  31  provides an indication of earthquake activity, and electrically controllable valve  21  may be shut off in conformity with detecting an earthquake. Temperature detector  32  and seismic activity detector  31  may be switches activated upon detection of the associated event, or they may be sensors and the detection circuitry may be provided within control circuit  30 .  
         [0022]    Control panel  34  provides for manual control of control circuit (and thus the system of the present invention) via controls  36  and provides an indication of operational state via visual indicators  35  and a beeper  37  for providing an audible alarm. Remote control and indication of state may be provided by a modem/network interface  33  which may be coupled to a telephone network or other suitable network connection such as Digital Subscriber Link (DSL), cable modem or a router connection deriving therefrom. Control operations may be performed within control circuit  30  in response to codes received by modem/network interface  33  and system status may be provided by control circuit  30  to a remote location via modem/network interface  33 .  
         [0023]    Within control circuit  30 , control is provided by program code executed from memory  42  by a processor  41 . Memory  42  and processor  41  are provided by a programmable logic controller  40 , although other forms of processing system such as single board computers, may be used to implement control algorithms in accordance with the present invention and dedicated circuits may also be used. A particular advantage of programmable logic controller  40  is that remote control modules such as X10 controllers are commercially available to couple control circuit  30  to various sensors, e.g. packaged motion sensors are available with X10 connections that transmit signals via household  10  power lines, making it unnecessary to directly wire motion sensors to control circuit  30 . Additionally, controls are available so that electrically controllable valve could be operated by an X10 controller. However, particular advantages associated with a manual override within the present invention might make remote control of electrically controllable valve  21  undesirable.  
         [0024]    Programmable logic controller  40  controls electrically controllable valve  21  via relay K 1 . A manual override timer  43  provides a timeout when a system user operates a manual “on” control from control panel  34 . Relay K 2  is activated when the manual “on” control is pressed, turning on electrically controllable valve  21  until the timeout occurs (generally one hour). The system uses a battery  38  to supply operating power for control circuit  30 , but the manual override may be used in event of failure of portions of the system or loss of the programmable logic controller  40  control program. Loss of household  10  primary power may also affect portions of the system, depending on implementation, so manual override timer  43  may also be useful during a power failure. A battery charging and sensing circuit  39  connects to battery  38  from control circuit  30 . Battery  38  is maintained in a charged state by charging and sensing circuit  39 , and automatic operation of the system may be held off while battery  38  has insufficient charge to properly operate the system.  
         [0025]    Since battery power should be conserved by the system, electrically controllable valve  21  is preferably a pulse type valve (latching solenoid valve). Therefore, programmable logic lab controller  40  or manual override timer  43  activate electrically controllable valve  21  using a pulse (generally on the order of 0.5 second) to either turn on or turn off electrically controllable valve. Special circuits within control circuit  30  may be used to produce the pulses, or programmable logic controller  40  may be programmed to produce the desired pulse. Manual override timer  43  will generally comprise a one-shot pulse generator that generates a pulse to turn off electrically controllable valve  21  after the timeout has occurred.  
         [0026]    Referring now to FIG. 3, details of control panel  34  are depicted. Controls are provided as follows: Reset switch  36 A provides a means to reset programmable logic controller  40  and other circuits within control circuit  30 ; water on switch  36 B provides one hour of manual override water flow via manual override timer  43 ; water off switch turns of water flow  36 C; and learn mode switch  36 D activates a learn mode of operation. Indicators  35  are provided on control panel  34  and may also be located remotely. A monitor indicator notifies a user that the system is actively monitoring water flow; an away indicator indicates that lack of motion sensor activity has caused the system to enter “away” mode. A seismic alarm, low temp alarm and water flow alarm indicator are used to indicate earthquake detect, freezing detect or leak detect, respectively. A buzzer  37  is integrated within control panel  34  to provide an audible alarm, generally in accordance with a logical-OR combination of the above alarm indications.  
         [0027]    Learn mode operation in the context of the present invention refers to the determination of water usage cycles. The present invention uses a “short” cycle and a “long” cycle to control operation of electrically controllable valve  21 . A short cycle is the time period that water is permitted to flow before an alarm condition is entered. This permits appliances such as icemakers to operate. A long cycle is the time period that water is permitted to flow when motion sensors have detected activity recently within household  10 , this permits an occupant to use water normally, e.g., to draw a bath, without the short cycle expiring, causing an interruption of water flow. The short and long cycles are adjustable, depending on the programmable logic controller program. Code within the programmable logic controller program measures typical water usage by occupants of the household and automated systems such as icemakers and possibly sprinklers (if a connection is not provided to override the short cycle for sprinkler operation). The typical use is turned into operational variables to control the short and long cycles, generally the long cycle will be within the range of ½ to 2 hours and the short cycle within the range of 1 to 5 minutes. The programmable logic controller program adapts the cycles when learn mode is selected and learn mode is generally self-terminated after, for example a 24 hour period.  
         [0028]    Referring now to FIG. 4, operation of a system in At accordance with an embodiment of the present invention is depicted. First, a battery-charging loop is activated (step  60 ) that controls charging of battery  38 , so that operation may be initiated only after battery  38  has sufficient charge to operate the system. The battery voltage is sampled and when the battery voltage is sufficient (decision  61 ), the motion sense flow control program is started (step  62 ). During operation, a manual override switch may interrupt operation (decision  63 ) to pulse the valve control circuit (step  64 ) to provide or stop water flow. If water on switch  36 B was pressed (i.e. the water is on) (decision  65 ) then the manual override timer  66  provides the timeout that pulses valve control (step  64 ) to shut off the valve.  
         [0029]    Referring now to FIG. 5, further operation of a system in accordance with an embodiment of the invention is depicted. FIG. 5 illustrates the automatic operation of the motion sense flow control program activated in step  62  of FIG. 4. Water flow is monitored (step  70 ) and if a short cycle is detected (decision  71 ) corresponding to detection of a normal use of it water, the short and long cycle timers are reset (step  75 ). If motion is detected from a motion sensor (decision  72 ) and the water is currently turned off (decision  73 ) the water is turned on (step  74 ). If motion was detected in step  72 , the short and long cycle timers are reset (step  75 ). Next, the system checks for a long cycle timeout (decision  76 ), if the long cycle was exceeded, the water is shut off (step  78 ) and an alarm indication is sent (step  79 ) which may be a visual indication via indicator  35 , an audible alarm via buzzer  37 , a remote message via modem/network interface  33 , or a combination of the above. If motion is not detected for a long period (decision  80 ) (generally 12 hours), then away mode is activated (step  81 ), which essentially sets the long cycle to zero causing an alarm on any water usage.  
         [0030]    While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form, and details may be made therein without departing from the spirit and scope of the invention.

Technology Category: 4