Abstract:
A system, method, and computer readable medium directed to communication with a remote component in an aircraft environment are described. The system includes the remote component in the aircraft environment to control a single phase alternating or direct current input drawn from a constant voltage power source, and a controller in the aircraft environment configured to monitor the current input to the remote component and determine a message from the remote component based on a current pattern in the current input.

Description:
BACKGROUND OF THE INVENTION 
     Exemplary embodiments pertain to the art of signal transmission. 
     In many systems that include multiple components, several of those components may be remote such that they are not visible or accessible to an operator. In these systems, the ability to receive communication regarding the health or other information about the remote components may be desirable. Such information may facilitate more reliable operation of the system through better control of the remote components, for example. However, current forms of receiving such information involve the addition of discrete signal wires or communication buses. For example, the additional wires may present issues with respect to added weight (e.g. in aircraft systems) and/or technical complexity. 
     BRIEF DESCRIPTION OF THE INVENTION 
     Disclosed according to an embodiment is a system to communicate with a remote component located in an aircraft environment, the system including the remote component disposed in the aircraft environment configured to control a single phase alternating current or direct current input drawn from a constant voltage power source; and a controller disposed in the aircraft environment configured to monitor the current input to the remote component and determine a message from the remote component based on a current pattern in the current input. 
     According to another embodiment, a method of communicating within a system, located in an aircraft environment, including a remote component includes generating, by the remote component disposed in the aircraft environment, a current pattern within current input to the remote component from a constant voltage power source of the system; monitoring, by a controller disposed in the aircraft environment and remote to the remote component, the current input to detect the current pattern, the current input being single phase alternating current or direct current; and associating, using a memory device, the current pattern with a corresponding message from the remote component. 
     Also disclosed according to yet another embodiment is a non-transitory computer readable medium storing instructions therein which, when processed by a processor, cause the processor to implement a method of receiving communication from a remote component of a system located in an aircraft environment. The method includes monitoring a single phase alternating current or direct current input from a constant voltage power source to the remote component; identifying a current pattern in the current input; and associating the current input with a corresponding message from the remote component. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
         FIG. 1  is a block diagram of a system according to an embodiment of the invention; 
         FIG. 2  details the controller shown in  FIG. 1  according to an embodiment of the invention; 
         FIG. 3  is an exemplary supply current when the power source supplies alternating current to the remote component; 
         FIG. 4  is a current pattern resulting from the exemplary supply current shown in  FIG. 3 ; 
         FIG. 5  depicts current patterns that convey a discrete status as the message according to an embodiment of the invention; 
         FIG. 6  depicts current patterns that convey an analog value as the message according to an embodiment of the invention; 
         FIG. 7  depicts current patterns that convey an analog value as the message according to another embodiment of the invention; 
         FIG. 8  depicts message start and stop signals in a current pattern according to an embodiment of the invention; and 
         FIG. 9  is an exemplary flow diagram of a method of communicating with a remote component according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. 
     As noted above, traditional communication (via wires or communications buses) with remote components of a system may present issues related to weight and complexity, for example. These issues are prevalent in aircraft systems. For example, knowing the status of lights disposed on the outside of an aircraft may be desirable but the addition of wires to those lights may be impractical. Embodiments of the system and method described herein involve the use of existing controlled power input lines to the remote components for communication. Specifically, embodiments detail the remote component controlling its current demand (e.g., by controlling resistance) from a constant voltage source and a controller monitoring the current draw to receive communication from the remote component. 
       FIG. 1  is a block diagram of a system according to an embodiment of the invention. The system includes the remote component  110  supplied with power from a constant voltage power source  120 . In an aircraft environment, for example, the supplied power may be single phase alternating current or direct current power. Although one remote component  110  is shown and discussed with reference to  FIG. 1  for explanatory purposes, in various embodiments of the invention, the system may include any number of remote components  110  that communicate as discussed below. Communication by the remote component  110  via modulation of the power supplied from the power source  120  may be self-initiated. That is, the remote component  110  conveys information (e.g., due to a change in status of a parameter, due to an event trigger, due to a defined time trigger) without being prompted. A controller  130 , which may be housed with the power source  120  as shown in  FIG. 1  or which may be a separate component itself, monitors the input current  105  to the remote component  110 . The controller  130  detects a current pattern  250  ( FIG. 2 ) in the input current  105  to the remote component  110 , determines a message  260  ( FIG. 2 ) corresponding with the current pattern  250 , and transmits the message  260  to other components of the system via a communication bus  140 . Exemplary messages  260  may convey health status, temperature, pressure, and flow information related to the remote component  110 . 
       FIG. 2  details the controller  130  shown in  FIG. 1  according to an embodiment of the invention. The controller  130  includes an input interface  210 , one or more processors  220 , one or more memory devices  230 , and an output interface  240 . The controller  130  input interface  210  receives the current pattern  250  being sent from the power source  120  and modulated by the remote component  110 . The power source  120  may supply alternating current (ac) or direct current (dc) to the remote component  110 . The processor  220  identifies the current pattern  250  and matches it with a corresponding message  260  based on instructions and an association stored in the memory device  230 . For example, as shown in  FIG. 2 , the memory device  230  may store a look-up table with current patterns  250   a - 250   n  and corresponding messages  260   a - 260   n . The output interface  240  is used to communicate the message  260  corresponding with the identified current pattern  250  over the communication bus  140 . 
     When the power source  120  supplies alternating current (ac, the controller  130  monitors the root mean square value of the current (Irms) in order to ascertain the current pattern  250  and corresponding message  260 .  FIG. 3  is an exemplary supply current when the power source  120  supplies ac to the remote component  110 . In this case, the controller  130  determines the root mean square value of the current (Irms) as the current pattern  250 . Thus,  FIG. 4  is the current pattern  250  resulting from the exemplary supply current shown in  FIG. 3 . When the power source  120  supplies direct current (dc) or ac, the remote component  110  may control when the supply current from the power source  120  is turned on or turned off (i.e. generate current-on and current-off pulses) as a way to generate the current pattern  250 . The remote component  110  includes one or more processors (not shown) that control the current demand from the constant voltage power source  120  to generate the current pattern  250 . In alternate embodiments, the remote component  110  may also generate a current pattern  250  in other ways. Exemplary current patterns  250  and messages  260  are discussed below for explanatory purposes, but the examples are not intended to limit the types of current patterns  250  or messages  260  contemplated as embodiments of the invention. 
       FIG. 5  depicts current patterns  250   a ,  250   b  that convey a discrete status as the message  260  according to an embodiment of the invention. In the exemplary embodiment shown in  FIG. 5 , the two states represented by the two current patterns  250   a ,  250   b  are distinguishable based on the length of time that the remote component  110  is drawing current (periods  510  and  520 ). In this example, the remote component  110  is drawing current for a period  520  that is twice as long to generate the current pattern  250   b  than the period  510  to generate current pattern  250   a . Other variations in the periods  510 ,  520  of the current patterns  250   a ,  250   b  are also possible. The current pattern  250   a  may correspond to discrete logic 1, which conveys a message  260  of “health status ok,” while current pattern  250   b  may correspond to discrete logic 0, which conveys a message  260  of “health not ok,” or vice versa. Other discrete messages  260  may be conveyed in this way, as well. The controller  130 , upon matching the monitored current pattern ( 250   a  or  250   b ) with the corresponding message  260 , may set a corresponding status bit on the communication bus  140 . 
       FIG. 6  depicts current patterns  250   n ,  260   m  that convey an analog value as the message  260  according to an embodiment of the invention. In this example, the length of time that the remote component  110  is not drawing current (distance between current-off pulses  610 ,  620  in seconds) at the remote component  110  is proportional to an analog value being conveyed as the message  260 . For example, the distance  610  in current pattern  250   n  may be proportional to a particular temperature or pressure value while the distance  620  in current pattern  250   m  is proportional to a different temperature or pressure value. As should be clear from the descriptions of the exemplary current patterns  250  in  FIGS. 5 and 6  that the current patterns  250   a ,  250   b  in  FIG. 5  may be used to convey analog values rather than discrete states while the current patterns  250   n ,  250   m  in  FIG. 6  may be used to convey discrete states rather than analog values in alternate embodiments. 
       FIG. 7  depicts current patterns  250  that convey an analog value as the message  260  according to another embodiment of the invention. In the embodiment shown by  FIG. 7 , the ratio between the length ( 710 ,  720 ) of a current-on pulse and the length ( 715 ,  725 ) of a current-off pulse is used to convey a message  260 . For example, the ratio of the lengths  710  to  715  may convey an air flow while the ratio of the lengths  720  to  725  may convey a different air flow as the message  260 . As should be clear from the examples, any current pattern  250  generated by the remote component  110  may be used to convey any message  260  from the remote component  110  to the controller  130  as long as both the remote component  110  and the controller  130  store a prior correspondence between the same current patterns  250  and respective messages  260 . 
       FIG. 8  depicts message start  810  and stop  820  signals for a current pattern  250  according to an embodiment of the invention. The start  810  signal alerts the controller  130  to note the current pattern  250  in the supply current following the start  810  signal. Once the controller  130  encounters the stop  820  signal, the controller  130  matches the current pattern  250  to a corresponding message  260 . Depending on the types of current patterns  250  stored for recognition and message  260  match in the controller  130 , the use of the start  810  and stop  820  signals may preclude inadvertent messages  260  from being conveyed through the normal operation of the remote component  110 . 
       FIG. 9  is an exemplary flow diagram of a method of communicating with a remote component according to an embodiment of the invention. At block  910 , the remote component  110  generating a current pattern  250  by controlling current draw may be through combinations of current-on and current-off pulses, as shown in the examples discussed above. Generating the current pattern  250  may include generating a start  810  signal preceding and a stop  820  signal immediately following the current pattern  250  to isolate the current pattern  250  for the controller  130 . The controller  130  detecting the current pattern  250 , at block  920 , involves the controller  130  monitoring the supply current from the power source  120  to the remote component  110 . The detecting may include detecting the start  810  and stop  820  signals. At block  930 , the controller matching the current pattern  250  with a message  260  involves the controller using correspondence information stored in the memory device  230 . The correspondence information may be stored in the form of a look-up table, for example. After identifying the message  260  corresponding to the detected current pattern  250 , the controller  130  communicating the message  260  to other parts of the system may be via the communication bus  140 . For example, the controller  130  may set a status bit on the communication bus  140  indicating a state of discrete logic conveyed by the message  260 . 
     While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims.