Patent Publication Number: US-2009218886-A1

Title: Remote actuation based on measuring electric current consumption

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority from U.S. Provisional Application for Patent filed on Feb. 29, 2008 and assigned Ser. No. 61/032,432, the contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND 
     The present invention relates to control systems and, more particularly, but not exclusively to controlling a poultry house using continuous measurements of electric current consumption of various instruments useful therein. 
     Control systems, such as systems based on a programmable logic controller (PLC) are usually connected to measuring devices on one hand, and, depending on some programmed logic, operate electric devices on the other hand. In many cases several controllers are used, each is operating one electric device or a group of devices. If one of the measuring devices or the controllers, or the operated devices, fails for any reason, or in case of a partial power failure, the controlled environment, such as a poultry house, may develop adverse conditions before anyone notices. 
     There is thus a widely recognized need for, and it would be highly advantageous to have, a control system devoid of the above limitations. 
     BRIEF SUMMARY 
     According to one aspect of the present invention there is provided an actuating device containing: 
     an electric current relay operative to connect an electric current source with an electric current consumer; 
     an electric current detector operative to measure electric current via an electric conductor connecting the electric current source and the electric current consumer to form current measurement; and 
     a current controller connected with the electric current relay and with the electric current detector, the current controller being operative to control the relay, to receive the current measurement, and to detect a predefined event associated with a state of the current relay and the current measurement. 
     According to another aspect of the present invention there is provided an actuating device wherein the electric current detector is a three-phase electric current detector; and wherein the electric current relay is a three-phase electric current relay. 
     According to still another aspect of the present invention there is provided an actuating device wherein the event is determined according to presence of the electric current, and/or level of the electric current, and/or temporal characteristics of the electric current, and/or elapsed time the electric current is present, and/or elapsed time a predefined value of the electric current is measured, and/or elapsed time the electric current is not present, and/or time of change of the state of the current relay, and/or time of the current measurement, and/or relation between the time of change of the state of the current relay and time of the current measurement. 
     According to yet another aspect of the present invention there is provided an actuating device wherein an external controller controls the electric current source and/or the electric current consumer. 
     Further according to another aspect of the present invention there is provided an actuating device wherein the event indicates operation of the electric current consumer, and/or inoperability of the electric current consumer, and/or irregular operation of the electric current consumer, and/or state of an external controller. 
     Yet further according to another aspect of the present invention there is provided an actuating device additionally containing a relay, the relay being controlled by the relay to perform break a contact and make a contact between at least two parts of the electric conductor. 
     Still further according to another aspect of the present invention there is provided an actuating device additionally containing a memory unit operative to store at least one event detection rule, the event detection rule operative to instruct the controller to detect the predefined event. 
     Even further according to another aspect of the present invention there is provided an actuating device additionally containing a communication unit operative to communicate the event to an external control system. 
     Additionally according to another aspect of the present invention there is provided an actuating device additionally containing a master controller communicating with at least one the controller. 
     Also according to another aspect of the present invention there is provided an actuating device wherein the master controller additionally containing a memory unit operative to store at least one event detection rule, the event detection rule operative to instruct the master controller to detect the predefined event. 
     Further according to another aspect of the present invention there is provided an actuating device containing a plurality of the electric current relay and a plurality of electric current detectors and wherein the event is associated with a state of a first current relay and a current measurement from an electric current detector associated with a second current relay. 
     Still further according to another aspect of the present invention there is provided an actuating device containing a plurality of the electric current relay and a plurality of electric current detectors and wherein the event is associated with: 
     a state of a current relay and a plurality of current measurements from a plurality of electric current detectors; 
     a state of a plurality of current relays and a current measurement; and 
     a plurality of states of current relays and current measurements from a plurality of electric current detectors. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples provided herein are illustrative only and not intended to be limiting. Except to the extend necessary or inherent in the processes themselves, no particular order to steps or stages of methods and processes described in this disclosure, including the figures, is intended or implied. 
     In many cases the order of process steps may varied without changing the purpose or effect of the methods described. 
     Implementation of the method and system of the present invention involves performing or completing certain selected tasks or steps manually, automatically, or any combination thereof. Moreover, according to actual instrumentation and equipment of preferred embodiments of the method and system of the present invention, several selected steps could be implemented by hardware or by software on any operating system of any firmware or any combination thereof. For example, as hardware, selected steps of the invention could be implemented as a chip or a circuit. As software, selected steps of the invention could be implemented as a plurality of software instructions being executed by a computer using any suitable operating system. In any case, selected steps of the method and system of the invention could be described as being performed by a data processor, such as a computing platform for executing a plurality of instructions. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in order to provide what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. 
       In the drawings: 
         FIG. 1  is a simplified block diagram of a remote controller unit containing contains a relay, a current sensor and a micro-controller; 
         FIG. 2  is a simplified block diagram of the micro-controller of  FIG. 1 ; 
         FIG. 3  is a simplified block diagram of a remote control system containing a remote controller unit similar to the remote controller unit of  FIG. 1 ; 
         FIG. 4  is a simplified flow chart of software program executed by the remote controller unit of  FIG. 3 ; and 
         FIG. 5  is a simplified flow chart of an alternative software program executed by the remote controller unit of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     The present embodiments comprise a control device operative to supply operating electric power to an operated electric device, to measure the electric current drawn by the operated electric device, and, according to programmed logic (rules) to cease the operating electric power and/or to communicate the information to another controller. The control device may also use information received from another controller to determine the required action. 
     The principles and operation of a control device according to the present invention may be better understood with reference to the drawings and accompanying description. 
     Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. 
     In this document, an element of a drawing that is not described within the scope of the drawing and is labeled with a numeral that has been described in a previous drawing has the same use and description as in the previous drawings. Similarly, an element that is identified in the text by a numeral that does not appear in the drawing described by the text, has the same use and description as in the previous drawings where it was described. 
     Reference is now made to  FIG. 1 , which is a simplified block diagram of a remote controller unit  10  according to a preferred embodiment of the present invention. The remote controller unit  10  preferably controls the operation of a device  11  by controlling the supply of electric power to the device  11 , preferably by connecting or disconnecting the electric current from an electric power supply  12 . Preferably, the electric power supply  12  and the device  11  are not parts of the remote controller unit  10 , however, in an alternative embodiment, the electric power supply  12 , the device  11  and the remote controller unit  10  are integrated into a single system. 
     It is appreciated that the electric power supply  12  can include, or connect to, another remote controller (not shown in  FIG. 1 ) for controlling the operation of the device  11 , preferably by controlling the power supply to the device  11 . 
     As seen in  FIG. 1 , the remote controller unit  10  preferably contains a relay  13 , a current sensor  14  and a micro-controller  15 . The relay  13  is preferably operative to connect and to disconnect electric current in an electric conductor  16  supplying current from the electric power supply  12  to the controlled device  11 . Preferably, the relay  13  connects or disconnects the electric current in accordance with a control signal supplied to its terminators (connectors)  17 . 
     The current sensor  14  is preferably operative to measure the current flowing through the conductor  16 . Preferably, the current sensor  14  provides the current measurement via its terminators (connector)  18 . 
     The micro-controller  15  is preferably operative to receive the current measurements from the current sensor  14  via connector  18  and to operate the relay  13  to connect or to disconnect the electric current to the device  11  by sending a control signal via connector  17 . The micro-controller  15  preferably contains a data link  19  that connects to a communication medium  20 . The communication medium  20  can use any kind of communication technology such as a communication bus, a serial data link such as USB, a wireless communication technology such as WiFi or Zigbee, power line carrier (PLC) technology, etc. The communication medium  20  preferably connects several micro-controllers  15 . 
     Reference is now made to  FIG. 2 , which is a simplified block diagram of the micro-controller  15  according to a preferred embodiment of the present invention. 
     As seen in  FIG. 2  the micro-controller  15  preferably includes a processor  21  connected via an output interface  22  to the relay  13 , and via an input interface  23  to the current sensor  14 . The relay  13  and the current sensor  14  are shown in  FIG. 1 , and not shown in  FIG. 2 . The processor  21  also preferably connects to a memory  24  and via a data link interface  25  to data link  20  (shown in  FIG. 1  and not shown in  FIG. 2 ). Memory  24  preferably contains software program  26  and rules  27 . 
     The software program  26  is preferably operative to provide instructions to the processor  21  to process the decision rules  27 . The micro-controller  15  is preferably operative to process the software program and accordingly perform the following actions:
         Receive information from other micro-controllers  15  via the communication medium  20  and data link interface  25 ;   Receive current measurements from the current sensor  14  via input interface  23 ;   Determine, and accordingly instruct the relay  13 , via output interface  22 , to connect or to disconnect the electric current in the conductor  16 ; and   Determine, and accordingly transmit information via the data link interface  25  and the communication medium  20 .       

     The micro-controller  15  preferably uses the decision rules to determine the instructions to the relay  13  and/or the information to send via the communication medium  20 . The information sent via the communication medium  20  is typically the state of the switch (connected or disconnected), current measurement, elapsed time associated with current measurement, etc. 
     It is appreciated that the micro-controller  15  can be preferably implemented as an integrated circuit. 
     Reference is now made to  FIG. 3 , which is a simplified block diagram of a remote control system  28  according to a preferred embodiment of the present invention. 
     As seen in  FIG. 3 , the remote control system  28  preferably includes a master controller  29  connected preferably via a data link  30  to one or more slave controllers  31 . Data link  30  is preferably a digital communication link, preferably similar to the data link  19  or the communication medium  20  of  FIG. 1 . 
     As seen in  FIG. 3 , the salve controller  31  preferably includes a control module  32 , preferably controlling one or more sets  33  of a switch  34 , a relay  35  and a current sensor  36 . The relay  35  is operative to connect or disconnect electric current via conductor  37  connecting a power supply  38  and a device  39 . The current sensor  36  measures the electric current through the conductor  37 . As an example of a preferred embodiment of the present invention the controller module  32  of  FIG. 3  controls three sets  33 . 
     The controller module  32  preferably includes a processor  40  connected via an output interface  41  to the switches  34  and via an input interface  42  to the current sensors  36 . The processor  40  also preferably connects to a memory  43  and via a data link interface  44  to data link  30 . Memory  43  preferably contains software program  45  and rules  46 . 
     The master controller  29  preferably contains:
         a processor  47     a memory  48  connected to the processor  47 , preferably containing software program  49  and rules  50 ;   a data link interface  51  connecting the processor  47  to data link  30 ;   a data link interface  52  connecting the processor  47  to an external computing equipment;   a user interface  53 , preferably containing user-input interface  54  and user output interface  55 .       

     It is appreciated that the operation of the devices  39  can also be controlled by external controllers  56  or  57 . 
     It is appreciated that remote controller unit  10  of  FIG. 1 , or the remote control system  28  of  FIG. 3  operate as an actuating device operative to actuate a remote device which is an electric current consumer. As described above the actuating device includes an electric current relay operative to connect an electric current source with the electric current consumer, and an electric current detector operative to measure electric current via an electric conductor connecting the electric current source and the electric current consumer. The actuating device also includes a processor or a micro-controller operative as a current controller and connected with the electric current relay and with the electric current detector. The current controller is operative to receive current measurements, to detect a predefined event associated with a state of the current relay and with the current measurement, and to control the relay according to a rule associated with the state of the current relay and with the current measurement. 
     Preferably, the actuating device also contains a relay operative to break and/or to make a contact between parts of said electric conductor connecting the power supply (electric current source) and the consumer device (electric current consumer). 
     The actuating device can be a single phase actuating device or a three-phase electric current detector. In this respect either or both the current sensor and the current relay can be single phase or three-phase devices. 
     Preferably, the actuating device can determine events according to either of:
         the presence of an electric current via the conductor connecting the power supply and the consumer device;   the level of the electric current;   temporal characteristics of said electric current, such as fluctuations, frequency of peaks or depressions, average values, etc.   elapsed time that the electric current is present;   elapsed time at which a predefined value of the electric current is detected;   elapsed time at which the electric current is not present, or is below a predetermined value;   time of change of the state of the current relay;   time of at which the current is measured;   the relation between the time of change of the state of the current relay and time of the current measurement;   etc.       

     It is appreciated that the actuating device can use any combination of the above examples to determine an event. 
     Preferably, the actuating device can measure and control the current to the consumer device even when an external controller (such as controller  56  or  57  of  FIG. 3 ) also control the electric current source or the electric current consumer. It is appreciated that the actuating device preferably supervises the external controller. 
     Preferably, the actuating device determines events that indicate any of:
         the operation of the electric current consumer;   the inoperability of the electric current consumer;   an irregular operation of the electric current consumer;   the state of the external controller.       

     Preferably, the actuating device detects an event according to event detection rules stored in a memory unit of the actuating device, and to connect or disconnect the current between the power supply and the consumer device according to control rules also stored in the memory of the actuating device. 
     Preferably, the actuating device also communicates the events to an external control system via a communication unit and a communication medium that can be wired or wireless. 
     Preferably, the actuating device contains a master controller controlling slave controllers wherein each slave controller functions as an actuating device. The master controller preferably contains a memory unit storing event detection rules and/or control rules. The event detection rules are operative to instruct the master controller to detect said predefined event and the control rules are operative to instruct the master controller to instruct a slave controller to connect or to disconnect the current to a consumer device. It is appreciated that the slave controller can accept such instructions from the master controller, or from another slave controller or from another actuating device. It is also appreciated that the actuating device or the slave controller can accept an event from the master controller, or from another slave controller or from another actuating device and process a control rule associated with that event. 
     Preferably, the actuating device contains and/or controls a plurality of electric current relays and a plurality of electric current detectors. In such case, event detection rules and/or control rules can be associated with the states a plurality of current relays and/or current measurements from a plurality of electric current detectors. 
     Reference is now made to  FIG. 4 , which is a simplified flow chart of software program  45  according to a preferred embodiment of the present invention. 
     As seen in  FIG. 4 , software program  45  starts with step  58  preferably by measuring electric current. Software program  45  preferably proceeds to steps  59  and  60  to evaluate the current measurement. If no current is measured and no current is expected software program  45  continues measuring the current until either a current is measured or current is expected. If current is measured, software program  45  preferably proceeds to step  61  to measure consumption. 
     Consumption in this case typically refers to executed work such as heating, rolling a conveyor belt, for example to supply food, etc. Consumption is typically measured by measuring the time current is present. Alternatively, the value of the current measurement is integrated over time to calculate work and estimate the quantity of the relevant consumption. 
     Software program  45  preferably proceeds to step  62  to evaluate again if current is expected. For example, for supplying food or for supplying heat current is expected for a predetermined maximal period and then should stop. If, at step  62  or at step  60 , current is still measured, then software program  45  preferably proceeds to step  63  to provide an alarm, typically indicating a relay fault. 
     If current is still expected, for example if the supply period did not yet elapse, software program  45  preferably proceeds to step  64  to evaluate if the measured current is within a predefined permitted range. If the measured current is not within the permitted range software program  45  preferably proceeds to step  65  to provide an alarm, preferably indicating a faulty consumer. For example, an over heating heater. 
     Reference is now made to  FIG. 5 , which is a simplified flow chart of software program  45  according to an alternative preferred embodiment of the present invention. 
     As seen in  FIG. 5 , software program  45  starts with step  66  preferably by measuring electric current. Software program  45  preferably proceeds to steps  67  and  68  to evaluate the current measurement. If no current is measured and no current is expected software program  45  continues measuring the current until either a current is measured or current is expected. If no current is measured, software program  45  preferably proceeds to step  69  to provide an alarm, typically indicating a relay fault. Software program  45  preferably proceeds to step  70  to check whether a backup relay is available. If a backup relay is available, software program  45  preferably proceeds to step  71  to operate the backup relay. 
     If current is measured when there should be no current (step  72 ), software program  45  preferably proceeds to step  73  to provide an alarm, typically indicating a relay fault. 
     If current is expected and measured, software program  45  preferably proceeds to step  74  to evaluate if the measured current is within a predefined permitted range. If the measured current is not within the permitted range software program  45  preferably proceeds to step  75  to provide an alarm, preferably indicating a faulty consumer. For example, an over heating heater. Software program  45  then preferably proceeds to steps  70  and  71  to operate a backup relay if such is available. 
     It is appreciated that the software program  49  can be implemented in a similar manner to the software program  45  as described in accordance to  FIGS. 4 and 5 . 
     It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. 
     Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.