Patent Publication Number: US-8984675-B2

Title: Control system for a plurality of toilets and related method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/841,676, filed on Aug. 31, 2006. The disclosure of the above application is incorporated herein by reference in its entirety. 
    
    
     FIELD 
     The present disclosure relates to waste management and, more particularly, to a control system for a plurality of toilets and related method. 
     BACKGROUND 
     The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. 
     Toilet systems may require dedicated sensors that indicate fill levels for a holding tank. In applications including multiple toilets coupled to a common holding tank, each toilet may be responsive to a respective level sensor. The sensor may indicate tank fill status and whether a flush lockout is necessary. A flush lockout may be necessary if the tank is full. Multiple toilets may therefore result in holding tanks littered with sensors. 
     Further, each of the sensors may need to communicate with a control module on each respective toilet. Thus multiple cables may need to be run to respective toilets from the holding tank. 
     SUMMARY 
     An adapter includes an interface module that receives signals from a first sensor that indicate a first fill status of a holding tank. A control module of the adapter generates a control signal to restrict a flush capability of a toilet based on the first fill status. The toilet is at least partially controlled by a toilet control module that responds to the control signal. An isolation module of the adapter isolates the interface module and the control module from at least one of voltage and current fluctuations that are external to the adapter. 
     In other features, the control module compares the first fill status to a predetermined shut-off fill status that indicates that the holding tank is full. The control module indicates that the holding tank is full by illuminating a first light-emitting device. The interface module receives signals from a second sensor that indicate a second fill status of the holding tank. The control module compares the second fill status to a predetermined notification fill status that indicates that the holding tank is becoming full. 
     In other features, the control module indicates that the holding tank is becoming full by illuminating a second light-emitting device. A third light-emitting device is active in response to the isolation module electrically communicating with at least one of the toilet control module and the first sensor. The first, second, and third light-emitting devices comprise light-emitting diodes. 
     In other features, the isolation module includes an opto-isolator circuit. The opto-isolator circuit includes at least one of an optical isolator, an optocoupler, a photocoupler, and a photo metal oxide semiconductor (photo MOS). The control module bases the restriction on a variation in a predetermined current from the interface module. The predetermined current is based on the first sensor signal. 
     In other features, a toilet control system includes the adapter and further includes the holding tank. The first sensor communicates with contents of the holding tank. The toilet system also includes a plurality of adapters and a plurality of toilets and respective toilet control modules. Each of the adapters receives signals from the first sensor and controls one of the toilet control modules based on the signals. 
     Alternatively, the toilet control system includes a plurality of toilets and respective toilet control modules. The adapter controls the toilet control modules based on the signals. Alternatively, the toilet control modules respond to adapter signals that are merely translations of sensor signals. The first sensor includes at least one of a capacitive sensor, a reed switch, a Hall effect sensor, a mechanical float switch, an electro-mechanical float switch, an optical sensor, and an acoustic sensor. 
     Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG. 1  is a simplified schematic diagram of a control system for a plurality of toilets according to the present disclosure; 
         FIG. 2  is a functional block diagram of an adapter for the control system of  FIG. 1 ; 
         FIG. 3  is a simplified schematic view of a control system for a plurality of toilets according to the present disclosure; 
         FIG. 4  is another adapter according to the present disclosure; 
         FIG. 5  is a simplified schematic view of a control system for a plurality of toilets according to the present disclosure; 
         FIG. 6  is a functional block diagram of a toilet control system including the adapter of  FIG. 4 ; and 
         FIG. 7  is a simplified schematic diagram of a plurality of adapters according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The following description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical or. It should be understood that steps within a method may be executed in different order without altering the principles of the present disclosure. 
     As used herein, the term module refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. 
     In one particular application, the teachings of the present disclosure may be used in connection with a vehicle having a plurality of toilets and a common waste holding tank. For example, the present teachings may be used with a seagoing vessel with a plurality of toilets connected to a common on-board holding tank. Various other vehicle and non-vehicle applications are anticipated within the scope of the present disclosure. 
     The present disclosure may be utilized with various toilets including, but not limited to, macerator toilets. One suitable toilet for use with the present teachings is shown in described in U.S. Ser. No. 791,953 entitled Macerator Toilet and filed on Apr. 13, 2006. U.S. Ser. No. 791,953 is hereby incorporated by reference in its entirety. 
     Referring now to  FIG. 1 , an electronic control system in accordance with the present disclosure is illustrated and identified at reference numeral  10 . The control system  10  is shown operatively associated with a plurality of toilets  12 . As illustrated, the system  10  is shown associated with four toilets  12 . As will be appreciated more fully below, however, the system  10  may be readily adapted within the scope of the present teachings to accommodate a greater or lesser number of toilets  12 . The flush toilets  12  illustrated in the drawing may be macerator toilets  12 . Other types of flush toilets may also be used. 
     Each of the toilets  12  is associated with a separate electronic control module  13  and a user interface  14 . A suitable electronic control module and user interface are described in further detail in commonly assigned U.S. Ser. No. 60/792,381 entitled flush toilet control system and related method. U.S. Ser. No. 60/792,381 is hereby incorporated by reference in its entirety. Each of the toilets  12  may be in communication with a waste holding tank  15 . For vehicle applications, the waste holding tank may be an on-board waste holding tank. 
     The control system  10  may include one or more tank level sensors  16 ,  18  for sensing the level of waste within the waste holding tank  15 . Each tank level sensor  16 ,  18  may include a plurality of reed switches, for example. The sensors  16 ,  18  may also include Hall effect sensors and/or any other type of magnet based sensor. The sensors  16 ,  18  may also include capacitive type sensors that have specific fields and high frequencies. Further, the sensors may include mechanical or electromechanical float sensors, optical sensors, and/or acoustic sensors. The control system  10  may also include a switch  19  to switch from one type of sensor to another. In other words, the system may interact with different tanks and/or different sensors. The control system  10  may be switched to a mode that corresponds to the given sensor type. 
     The plurality of sensors may include a first electromechanical sensor  16  for generating a signal to indicate that the holding tank is substantially full and a second sensor  18  to indicate that the holding tank  15  is partially full. 
     The user interface  14  may include an indicator  17  for indicating a level of waste in the holding tank  15 . The indicator  17  may cooperate with the tank level sensors  16 ,  18  and may be controlled by the associated control module  13  to differentiate between various levels within the holding tank  15 . The indicator  17  may indicate when the holding tank  15  is partially full and substantially full. The indicator  17  may include a graphical representation of a holding tank  15 , which may be illuminated by a light-emitting device that may include a permanent or varying color. The color may indicate available capacity. 
     For example, the indicator  17  may be in a first color (e.g., yellow) when the holding tank  15  is partially full (e.g., three-quarters full), a second color (e.g., red) when the holding tank  15  is substantially full, and a third color (e.g., white) when the holding tank  15  is less than half full. The control system  10  may automatically use the control modules  13  of the toilets  12  to implement a “Lockout” mode upon sensing of a tank level above a predetermined level (e.g., approximately 90% full). In other words, the control modules  13  may lockout some or all of the toilets  12  to prevent overfilling of the holding tank  15 . Alternatively, the user interface  14  may include multiple indicators, such as first, second, and third indicators  17 ,  21 ,  23  that may all include different colored light-emitting devices, such as light-emitting diodes (LEDs). The indicators  17 ,  21 ,  23  may represent different tank fill status levels. 
     The control system  10  may include an adapter  20 . The adapter  20  may be located remote from the toilet  12 . The adapter  20  is embodied as a Multiple Toilet Adapter (MTA), however Single Toilet Adapters (STAs) are also contemplated and will be discussed later within the present disclosure. The adapter  20  receives signals from the sensors  16 ,  18  indicative of the holding tank  15  level. The adapter  20  is also coupled to the control module  13  of each of the toilets  12  through a multi-conductor cable or bus. The adapter is powered by a battery  22  although various other power sources may be used. 
     The adapter  20  may operate to translate the characteristics of the sensors  16 ,  18  directly to each of the plurality of toilets  12  and respective control modules  13 . In this regard, the adapter  20  functions to replicate and/or multiplex the signals received from the sensors  16 ,  18 . In this manner, the signals generated by the adapter  20  and directed to the individual toilets  12  are independent signals that can easily be routed to each of the toilets  12 . These signals may be isolated from one another. Signals from the adapter  20  may be referred to as control signals. The control signals may include translations of sensor data and/or signals that control functions of the control modules  13 . 
     In operation, when the holding tank  15  is less than the predetermined amount full (e.g. less than three-fourths full), the adapter  20  may generate a corresponding signal for each of the control modules  13  to illuminate the first indicator  17  and allow full operation of the toilet  12 . When the holding tank  15  reaches the predetermined level, the second sensor  18  generates a signal that is replicated by the adapter  20 . The control modules  13  may respond to this replicated signal by illuminating a second indicator  21  of each of the user interfaces  14 . The second indicator  21  indicates to the user that the system  10  remains fully functional, but the holding tank  15  has reached the predetermined fill status. The control modules  13  may also shut off toilet pumps so that the toilets do not continue to pump waste to the holding tank  15  based on sensor signals. 
     When the holding tank  15  reaches a substantially full level, the first sensor  16  generates a signal that is again replicated by the adapter  20 . This replicated signal in turn may control the control modules  13  to illuminate a third indicator  23  of each of the user interfaces  14 . Either or both of the control modules  13  and the adapter  20  may use the first or second sensor signals to limit flushing of the toilets  12 . The adapter  20  may also include diagnostic LEDs  30 ,  32 ,  34  that may indicate tank full, tank partially full, and connection to the sensors  16 ,  18 , respectively. 
     Referring now to  FIG. 2 , the adapter  20  may include an interface module  50 , a control module  52 , and an isolation module  53 . The control module  52  may include a vessel bridge module  54 , a pump relay module  56 , a shut-off module  58 , tank level modules  60 ,  62 , and a power module  64 . The interface module  50  interfaces with the sensors  16 ,  18  that sense data from the tank  15 . Numerous sensors may sense data from the tank although only two are illustrated. The control module  52  may determine the tank level based on sensor signals and may also determine appropriate responses to the tank levels. The control module  52  may determine the type of sensors attached and/or the number and type of toilets attached. 
     The isolation module  53  isolates the adapter  20  and the sensors  16 ,  18  from external variances in current and/or voltage. In other words, the isolation module  53  makes a varying load appear as a constant current load. In applications where different toilets  12  are interconnected to the adapter  20  through different lengths of cable, the isolation module  53  may eliminate problems associated with different line voltages. The toilets  12  may be connected to the adapter  20  via the isolation module  53  over a length of 100 feet or more. 
     The interface module  50  interfaces with the sensors  16 ,  18  that sense data from the tank  15 . The sensors  16 ,  18  may always signal their presence. The interface module  50  may provide a predetermined constant current to the control module  52  based on the sensor signals. The sensors  16 ,  18  may provide variations in the current in response to sensing that the holding tank  15  is filling. The control module  52  may base responses to sensor signals on fluctuations in the constant current. 
     For example, the sensors  16 ,  18  may draw constant 12 milliamps (ma) of current. The control module  52  may determine that if the interface module  50  receives 12 ma, then the holding tank  15  is empty. If the interface module indicates 20 ma, the holding tank  15  is full. If the interface module indicates 25 ma or more, then the sensors  16 ,  18  may be shorted. 
     The tank level modules  60 ,  62  may determine an exact level of the tank  15  based on the sensor signals but may only respond to predetermined notification and full levels. The sensors  16 ,  18  may constantly provide signals to the tank level modules  60 ,  62 . The notification levels may be any level less than full, such as three-quarters full. The bridge module  54  may isolate portions of the adapter  20  from the toilets  12 . The pump relay module  56  may send a signal to the vessel (that includes the toilet system) that the tank may be full and may need to be pumped out. The pump relay module  56  may also relay various other information to the vessel, such as that the tank is empty and/or not attached. 
     The control module  52  may determine the tank level based on sensor signals and may also determine appropriate responses to the tank levels. Appropriate responses may include lighting indicators  17 ,  21  to indicate tank levels. For example, the tanks level module  60  may control a red LED when the tank is full. The tank level module  62  may control a yellow LED when the tank is three-quarters full. The power module  64  may also maintain another indicator  74 , such as a green LED, to indicate that the adaptor  20  is receiving adequate power. The shut-off module  58  may lock out attached toilets when the sensors are disconnected, shorted, and/or when the tank is full. 
     The isolation module  53  maintains isolation from external power sources so that a relatively constant current is used by the control module  52  to control the adapter  20 . For example, large ships may include multiple toilets in multiple locations. The toilets may include controllers that communicate with different ground lines. Alternatively, the toilets may have a common ground that has several voltage drops between a toilet and the adapter  20 . The isolation module  53  may completely isolate the rest of the adapter  20  from voltage/current fluctuations on both different ground lines and the common ground line. 
     The isolation module  53  may include a plurality of isolator circuits  55 , such as an optical isolator, optocoupler, photocoupler, a photo metal oxide semiconductor (photo MOS), an inductive isolator circuit or a capacitive isolator circuit that may be connected in parallel or in series. 
     The optical isolator circuits  55  may use short optical transmission paths to transfer signals between adaptor elements while keeping the signals electrically isolated. When a signal is applied to the input of the isolator circuits  55 , LED lights and a responsive light sensor may activate. A corresponding electrical signal may then be generated at the output of the opto-isolator circuit. The opto-isolator circuits separate the adaptor  20  from all external sources and provide a constant current regardless of external signals from the toilets  12 , common, or different grounds, etc. Therefore, lines to various toilets  12  may be long, connected to different grounds, include voltage drops, electrical noise, etc. 
     Referring now to  FIGS. 4-6 , a Single Toilet Adapter (STA)  100  is illustrated. The adapter  100  may include an interface module  102  to provide constant current from the sensors  16 ,  18 . The adapter  100  may also include an isolation circuit  106  that isolates the adapter  100  from external current variations. The adapter  100  may also receive on/off signals from the sensors  16 ,  18  instead of constant signals. The adapter  100  may also include a control module  107 . One adapter  100  may be provided for each toilet  12  in the system. 
     The adapter  100  may include LEDs  110 ,  112  that indicate that the holding tank  15  is full. The adapter  100  may also include LEDs  114 ,  116  that indicate that the toilet control module  13  has been notified of the tank condition. Another LED  118  may indicate that the sensors  16 ,  18  are properly connected and/or the toilet  13  is properly connected. 
     Referring now to  FIG. 7 , multiple Single Toilet Adapters  100 - 1 ,  100 - 2 , . . . , and  100 -N may receive signals from a single set of sensors  16 ,  18  and translate the signals to respective toilets. Basically, the adapters  100 - 1 ,  100 - 2 , . . . , and  100 -N detect the sensors  16 ,  18  and indicate an open circuit if the sensors  16 ,  18  are not connected. The isolation module  106  may detect sensors and determine the type of sensors that are attached, and the control module  107  may respond accordingly. 
     For example, if float sensors are attached, the adapter  20  need only respond to two conditions because float sensors may only have two conditions, open or closed. Open corresponds to either an empty tank or a disconnected sensor. Closed corresponds to a full tank or partially full tank. The isolation module  106  may also translate sensor information into an indication that the sensors are connected to the adapter  100 . 
     Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification, and the following claims.