Patent Publication Number: US-2015084649-A1

Title: Capacitive wire sensing for guarding applications

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Application No. 61/882,744, filed Sep. 26, 2013, entitled “Capacitive Wire Sensing for Guarding Applications,” having attorney docket number LGPL.195619, the entire disclosure of which is hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present invention generally relates to presence-sensing technology incorporated into guards and fencing. More particularly, the invention relates to incorporating a capacitance sensing system into a guard or fence for detecting the contact or presence of a person. 
     BACKGROUND OF THE INVENTION 
     It may be useful to detect the presence of a person coming into contact with a guard or fencing type material. Upon detection of a triggering event, such as contact, a variety of preprogrammed responses may be initiated. A need exists for a reliable presence-sensing technology for use with guarding and fencing type applications. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention generally relates to an apparatus for presence detection that incorporates a capacitive component into guards and or protective fencing. It should be understood that the invention contemplates incorporating a capacitive sensing device into a variety of items used for the protection of equipment or others, and that the invention is not limited to the specific item for which presence detection is provided. Additionally, the present invention is described as detecting/sensing the presence of a person or other being using exemplary components such as a low voltage power source and a processor within a capacitance sensing device. Although a final determination of presence may be conducted using a processor and/or software associated with the claimed apparatus, reference to sensing and/or detection “by” any portion of the guard, or a determination thereof by the processor, is not meant to be limiting. For example, a conductive signal detected by contact with a guard may be processed by software associated with a processor, and such processing may result in a final determination of presence or contact. In other words, a conductive frame or guard could be described as having “detected” presence, even though the detection determination was ultimately made in software associated with a processor. 
     In one embodiment, a capacitive component is secured to a portion of a guard. For example, a low voltage source may be secured to a perimeter of a guard. In a further embodiment, capacitive wiring is integrated into the frame supporting the guard. In further embodiments, a metal frame may be pulsed with a charge and used to monitor a change in capacitance based on contact with the metal frame. Software associated with the low voltage source and the capacitive wires/grids/metal frames may then make a determination of presence and/or contact of a body with respect to a guard. Based on a determination of contact or lack thereof, a corresponding output function, feature, indicator, and/or response may be activated. 
     In another illustrative aspect, the present invention includes a method for detecting presence with respect to a guard. The method includes receiving information provided by at least one capacitive component coupled to a perimeter of the guard, wherein the capacitive component is adapted to have a voltage based on the proximity of an object to the capacitive component; determining that a change in voltage satisfies a threshold amount; and based on determining that the threshold amount is satisfied, initiating a corresponding response. 
     In another embodiment, a method for detecting presence with respect to a guard comprises: receiving information provided by at least one capacitive component coupled to the guard, wherein the at least one capacitive component comprises a metal frame, wherein receiving information comprises providing the metal frame with a voltage to provide a charge to the metal frame, and determining that a change in voltage satisfies a threshold, wherein determining that a change in voltage satisfies a threshold comprises: (1) monitoring a change in voltage detected by the at least one capacitive component over a particular period of time; and (2) comparing the change in voltage over the period of time with the threshold. 
     In some aspects of the invention, a system and method are provided for incorporating presence-sensing technology into a capacitive guard device and/or storage locker. Based on coupling a capacitive sensing module to the guard device, a charge may be applied to the guard device, and the guard device may be monitored for a subsequent change in capacitance detection. In some aspects, the capacitive sensing module includes instructions, such as those embodied in software media discussed above, that adaptively measure and/or monitor the capacitance of the guard device. As such, a change in capacitance may be measured over time with respect to a baseline level of applied capacitance from the charge that the guard device is receiving. In one aspect, the capacitive sensing module may determine the detection of a human near the guard device, such as a human standing next to the guard device. In another aspect, the software associated with the capacitive sensing module (either directly coupled to the capacitive sensing module or remotely controlling the features of the capacitive sensing module from a remote computing device) may determine if the detected presence satisfies a threshold level of detection from either a proximity detection of user presence, or a detection of direct contact with the guard device. In one aspect, the capacitive sensing module is configured to detect a change in capacitance similar to the capacitive detection monitored and reacted to via a touchscreen device. 
     In one embodiment of the invention, a small voltage is applied to the guard device being monitored, such as a voltage within a minimal range required for detection and/or monitoring. The capacitive sensing module may receive information from the guard device (that is receiving the voltage), and determine when a change in such monitored voltage over time satisfies a threshold level of detection. As such, the capacitive sensing module may determine whether human contact and/or presence has been detected based on the received indication of change in monitored voltage. In one embodiment of the invention, a capacitive voltage divider (CVD) and/or a charge time measurement unit (CTMU) may be used to provide a detection algorithm for determination by the capacitive sensing module. In one aspect, a user may pre-set a sensitivity level and/or threshold requirement desired before triggering an indication of presence/contact. For example, an enclosure protecting a particular machine in a high-traffic area of a warehouse may experience multiple presence indications from users within a proximity of a guard device, but the sensitivity of the guard device may be set to only trigger a corresponding response when a stronger change in capacitance is detected, such as actual contact with the guard device. 
     Based on a determination of presence/contact, or lack of presence/contact, a variety of corresponding features may be triggered by the capacitive sensing module, according to embodiments of the invention. For example, an alarm may be activated, a surveillance camera may be triggered, a message may be sent to a mobile device, a message may be sent to a remote computing device, and the like. By triggering such alerts/notifications, a first user may be notified that a second user is attempting to open a guard device enclosing a protected area. In further aspects, an alert/notification may provide an indication of one of multiple different types of contact with the guard device, such as a determination that a user is trying to climb or circumvent the guard device. In another aspect, an alert may be triggered that corresponds to a particular item enclosed within a guard device. For example, an alert may be triggered that a user is attempting to use a machine enclosed within a guard device, with a portion of the guard not in place (e.g., the guard may be left partially open, and an alert is triggered to notify the user that the machine may not be operated while the guard gate is open). 
     Additional objects, advantages, and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. 
    
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWING 
       The present invention is described in detail below with reference to the attached drawing figures, wherein: 
         FIG. 1  is a perspective view of a representative guard, in accordance with embodiments of the invention; 
         FIG. 2  is an enlarged, perspective view of a portion of the guard of  FIG. 1 , in accordance with embodiments of the invention; 
         FIG. 3  is an enlarged, perspective view of a portion of the guard of  FIG. 1 , in accordance with embodiments of the invention; 
         FIG. 4  is a top perspective view of an assembled guard system, in accordance with embodiments of the invention; 
         FIG. 5A  is a perspective view of components of a guard system, in accordance with embodiments of the invention; 
         FIG. 5B  is a perspective view of components of a guard system, in accordance with embodiments of the invention; 
         FIG. 6  is a flow diagram of an exemplary method for detection using a guard, in accordance with embodiments of the invention; 
         FIG. 7  is an exemplary graphical display of the measure of contact detection with a guard using capacitance monitoring, in accordance with embodiments of the invention; 
         FIG. 8  is an exemplary computing device for use during capacitance monitoring, in accordance with embodiments of the invention; 
         FIG. 9  is an exemplary network diagram for accessing data from a capacitive sensing module, in accordance with embodiments of the invention; 
         FIG. 10  is an exemplary network environment for accessing data from a capacitive sensing module, in accordance with embodiments of the invention; 
         FIG. 11  is a flow diagram of an exemplary method for detection using a guard, in accordance with embodiments of the invention; and 
         FIG. 12  is an exemplary graphical display of the measure of contact detection with a guard using capacitance monitoring, in accordance with embodiments of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiments of the invention relate to incorporating a capacitance sensing system into a guard or fence for detecting the contact and/or presence of a person. In some aspects of the invention, a method for detecting presence with respect to a guard is provided. The method includes: receiving information provided by at least one capacitive component associated with the guard; determining that a change in voltage satisfies a threshold amount; and based on determining that the threshold amount is satisfied, initiating a corresponding response. 
     In another embodiment of the invention, a guard system for restricting access to an internal area using capacitance detection is provided. The guard system includes: a plurality of guards coupled to a plurality of vertical posts; and a capacitive sensing module coupled to the plurality of guards, wherein the capacitive sensing module comprises: (1) a charge component, (2) a monitoring component, and (3) a detection component. 
     In a further aspect, a capacitive guard device for monitoring and restricting user access is provided. The capacitive guard device includes a capacitive guard comprising: (1) a plurality of guard panels, each of the plurality of guard panels comprising a capacitive material, and (2) a plurality of vertical posts coupled to the plurality of guard panels, wherein each of the plurality of vertical posts comprises a capacitive material; and further wherein each of the plurality of vertical posts is coupled to at least one of the plurality of guard panels along a vertical axis of the plurality of guard panels to provide an enclosed space within the capacitive guard that is inaccessible by a user adjacent the vertical axis. Additionally, the capacitive guard device includes a capacitive sensing module coupled to at least a portion of one or more of the plurality of guard panels and the plurality of vertical posts, the capacitive sensing module comprising one or more of the following: (1) a charge component; (2) a monitoring component; (3) a detection component; (4) a charge component; (5) a monitoring component; (6) a detection component; (7) a calibrating component; (8) a communication component; (9) a power source; (10) an alerting component; (11) an authentication component; and (12) a database. 
     With reference now to the figures,  FIG. 1  illustrates a representative guard  10  that can be used in a variety of applications. Guard  10  has an outer frame  12  that supports a protective grid  14 . The frame  12  is typically formed from a steel material, but can be formed from other materials as well, such as other metallic and/or conductive materials configured to carry a charge. Similarly, the protective grid  14  is typically a metal grid, but may be made from another metallic and/or conductive material, according to some embodiments. The guard  10  shown in the figures is one possible configuration, but it should be understood that other configurations, shapes, etc., could be implemented depending on the particular guarding application. Moreover, the inventive concepts disclosed herein could be applied to many other applications, such as storage lockers, bins, etc. 
     Guard  10  also includes a power source  16  that provides low voltage power output to lead  18 . The power source  16  may be any power source configured to generate a charge for applying to the guard  10 . In some aspects, the power source  16  is an electrical wall outlet to which the guard  10  is coupled, while in other embodiments, the power source  16  is solar powered. In further aspects, the power source  16  includes a primary power source and a secondary power source, such as a primary coupling to an electrical outlet, and a secondary backup battery power source. In some embodiments, the power source  16  includes a surge protection device configured to protect one or more features of the power source  16 , and ensure the continued power supply to the capacitive sensing module during monitoring. As shown in the example of  FIG. 1 , a lead  18  is coupled to the frame  12 , such that a low voltage is applied to the frame  12  and the grid  14 . In some aspects, the lead  18  includes a single connection, while in further aspects, the lead  18  includes multiple connections to the frame  12  and/or grid  14 . 
     The lead  18  is also used to feed information to capacitive sensing module  20 . In some embodiments of the invention, the capacitive sensing module  20  includes one or more components for providing a charge to the frame  12  and/or grid  14 , one or more components for monitoring a change in capacitance with respect to the frame  12  and/or grid  14 , and one or more components configured to determine a corresponding output in response to the monitored detection. The capacitance measured across the frame  12  may be monitored by a processor in the capacitive sensing module  20  that uses software to generate a determination of contact or presence detection. In one embodiment, the Microchip® brand capacitive sensor may be used to determine when presence is detected. As such, while presence detection relies on the contact of a person or body with respect to the guard, a determination of the level of detection and/or the measurement of presence is conducted digitally, in software associated with one or more processors. In some aspects, as discussed below, the processor(s) used to determine a level of detection and/or the measurement of presence, and to initiate the corresponding response by the capacitance sensing module  20 , may be located within the capacitance sensing module  20 . Additionally, in further embodiments, a remote processor may be coupled to the capacitance sensing module  20  for determining a level of detection and/or the measurement of presence. 
     In some embodiments of the invention, the capacitive sensing module  20  is used to detect the presence and/or contact of a person or other being with a guard  10 , including a series of multiple guards  10  coupled together (e.g., a series of outer frames  12  and protective grids  14  coupled together). As will be understood, additional capacitive components (e.g., additional components configured to have and/or carry a charge), such as additional capacitive wire segments or leads, may be coupled to the outer frame  12 , the protective grid  14 , and/or the vertical post  26 . In further embodiments, wire segments may surround the frame, rather than attaching the leads  18  to the frame itself, to provide a charge and/or enable the capacitive monitoring of a charge applied to the grid  14 . In further embodiments, a capacitive sensing module  20  may be coupled to the guard  10  to both provide a minimal amount of charge to the guard  10  and to receive data corresponding to a change in capacitance. 
     In embodiments, capacitive sensing module  20  is used to monitor a change in capacitance over a specified amount of time. The capacitive component (outer frame  12  and protective grid  14 ) is adapted to have a voltage supplied by power source  16 . Such voltage information is collected via the capacitive component (the frame  12  and protective grid  14 ) and received by the processor in device  20 , which determines when a change in capacitance or voltage satisfies a threshold. Once a particular change in capacitance satisfies a threshold, a corresponding outcome function is triggered. For example, the guard  10  may include a warning light  22  or audible alarm  24  that are triggered when capacitive sensing module  20  detects a change in capacitance over the predetermined threshold, as shown in  FIGS. 1 and 3 . 
     As further depicted in  FIGS. 1-3 , the exemplary guard  10  includes a pair of vertical posts  26  on each side of the outer frame  12 . In embodiments, the vertical posts  26  are a conductive material configured to carry a charge applied to the guard  10 . As such, a voltage applied to the capacitive component (the outer frame  12  and the protective grid  14 ) may be carried from one guard  10  to an adjacent guard  10  based on coupling between neighboring vertical posts  26  and/or between neighboring outer frames  12  coupled to a common vertical post  26 . In the example of  FIG. 1 , each of the vertical posts  26  include a base plate  28  that may be secured to a surface, such as the ground or floor of a room, using bolts  30 . In the enlarged view of  FIG. 2 , a non-conductive coaster  36  is adjacent the base plate  28  and is positioned between the base plate  28  and the ground surface  56 . The non-conductive coaster  36  may be made from any material, or combination of materials, that does not carry a charge. For example, non-conductive coaster  36  may be an insulating material such as a plastic, rubber, cork, and/or other material. 
       FIG. 2  also includes further exemplary details of the bolts  30  used to secure the guard  10  to the ground surface  56 . In one embodiment, the bolts  30  are coupled to the base plate  28  using nuts  32  and non-conductive washers  34 . Non-conductive washers  34  may be made from any non-conductive material, or combination of materials, that does not carry a charge. As such, non-conductive washers  34  may be made from the same non-conductive material as the non-conductive coasters  36 . In order to decouple the guard  10  from any charge carried by and/or transmitted from an external environment, the base plate  28  of each vertical post  26  is coupled to the ground surface  56  using tightening mechanisms that prevent and/or interrupt flow of a charge/voltage to or from the guard  10 . For example, a bolt  30  and nut  32  may be made from a conductive material and may be used to couple the conductive vertical post  26  to the ground surface  56  without carrying a charge to or from the guard  10 . As such, in some embodiments of the invention, the vertical posts  26  are separated from direct contact with the ground surface  56  based at least in part on a non-conductive coaster  36  and/or non-conductive washer  34 , thereby providing a “floating” guard  10  system. 
     The guard  10  may further include any number of additional components coupled to the capacitive sensing module  20 , such as the audible alarm  24 . Multiple input/output (I/O) ports  46  may be provided in association with the capacitive sensing module  20 , which may couple one or more leads to transmit information to and from the capacitive sensing module  20 , such as leads  48  and  50 , which are coupled to insulator  52  in the example of  FIG. 2 . One or more different types of I/O components may be coupled to the capacitive sensing module  20 , and may be directly or indirectly coupled to the guard  10 , or to a series of guards  10 . For example, while warning light  22  and audible alarm  24  are shown coupled to a top edge of the outer frame  12 , such features may be located in a different position, such as the warning light  22  being positioned on a ceiling surface above the ground surface  56 , with a wireless connection (e.g., WiFi, zigbe, Bluetooth, etc.) between the warning light  22  and the capacitive sensing module  20 . Similarly, a central warehouse control may include an audible alarm  24  that is coupled, either by wire or wirelessly, to the capacitive sensing module  20 . In some aspects, one or more features for attaching a lead, such as leads  48 ,  50 , and  58  of  FIG. 3 , may couple an accessory and/or external component to the guard  10 , such as coupling mechanism  60  of  FIG. 3 . 
     With continued reference to  FIG. 2 , the guard  10  may include a conductive ring terminal  38  associated with the lead  18  that couples the capacitive sensing module  20  to the vertical post  26 . The conductive ring terminal  38  may be coupled to any portion of a capacitive component of a guard system to provide a charge to and/or provide monitoring of the guard system. In one example, the conductive ring terminal  38  is directly coupled to the vertical post  26  using bolt  40 , all of which features include a conductive/capacitive feature. Further, the vertical post  26  may be coupled to the outer frame  12  of the guard  10  using a capacitive coupling mechanism, such as the bolt  54 . Based on the coupling of such capacitive features, the power source  16  may provide power to the capacitive sensing module  20  via the power plug  42  coupled to I/O port  44 , which enables a charging component of the capacitive sensing module  20  to provide a charge to the guard  10  systems via lead  18  and conductive ring terminal  38 . 
     With reference to  FIG. 4 , an exemplary assembled guard system  62  includes a first guard panel  64 , a second guard panel  66 , a third guard panel  68 , and a fourth guard panel  70 . Based on coupling together for the first, second, third, and fourth guard panels  64 ,  66 ,  68 , and  70 , a guarded internal area D is separated from an unguarded area E shown in  FIG. 4 . As such, the assembled guard system  62  may be used to restrict access to one or more items stored within the guarded internal area D. While the example of  FIG. 4  depicts four guard panels in a series, joined to shared vertical posts  26  at each corner, embodiments of an assembled guard system  62  may include a different number of guard panels to provide an enclosed area, in a variety of different configurations and/or layouts. As will be discussed in more detail below, capacitance monitoring of the assembled guard system  62  may provide an indication that the internal area D has been accessed and/or the protection provided by the adjacent guard panels has been interrupted. 
     In the example of  FIG. 5A , an exemplary capacitive sensing module configuration  72  includes a capacitive sensing module  20 , a first I/O port  74 , a second I/O port  76 , a wireless connection  78 , a first external component  80 , a second external component  82 , and a ring terminal  84 . In some aspects, a capacitive sensing module  20  may be coupled to a capacitive component (e.g., the assembled guard system  62 ) via I/O port  74 , lead  18 , and ring terminal  84 , thereby enabling a charge to be applied to the capacitive component from the capacitive sensing module  20 . Further, in response to the applied charge transmitted via lead  18  and ring terminal  84 , one or more responses may be elicited by the capacitive sensing module  20 , such as a directly coupled first external component  80 , or a wirelessly coupled second external component  82 . In the exemplary capacitive sensing module configuration  86  of  FIG. 5B , the third I/O port  88  and the second I/O port  76  may be used to couple the capacitive sensing module  20  to the warning light  22  and the audible alert  24  via leads  48 ,  50 , and  58 . The multiple I/O ports  46  may be used to couple any number of additional or alternative external components to the capacitive sensing module  20 , which may be used to trigger a particular output based on the detected change in capacitance. In further embodiments, the external components such as the warning light  22  and the audible alert  24  may include an air horn, a buzzer, a building alarm, a remote alarm, or any other alerting and/or notification device coupling of the capacitive sensing module  20 . In some aspects, while the warning light  22  and the audible alert  24  are depicted in  FIG. 5B  as being directly coupled to the capacitive sensing module  20  based on leads  48 ,  50 , and  58 , a connection between an external component and the capacitive sensing module  20  may be wireless, and may be communicated directly or indirectly to one or more external components, such as a remote computer, a remote cellular device, a remote control center, and the like. 
     A variety of communication protocols may be used to control the variety of functions described above. For example, a two-way controller using a ZigBee® wireless communication protocol may be used. In some embodiments, a two-way communication protocol intended for use in automation (similar to Bluetooth®) may be utilized. In another embodiment, two separate microcontrollers may be used: one dedicated primarily for sensing purposes that, when it detects something, sends a signal to a secondary device/microcontroller that is programmed to initiate the corresponding response. 
     Turning now to  FIG. 6  an exemplary flow diagram  90  for monitoring capacitance using a capacitive sensing module  20  of a guard  10  is provided. In some aspects of the invention, a change in capacitance detected by the capacitive sensing module  20  is monitored over time. Based on satisfying a particular threshold change in capacitance, various other output functions and/or corresponding responses associated with the guard  10  system may be activated and/or enabled. As another example, a machine or operation may be disabled as an output function and/or corresponding response. Many other output functions may be implemented as well. In other words, capacitive sensing module  20  may initiate a variety of functions based on received data indicating contact or lack of contact, as determined using capacitance information. In one example, after contact is no longer detected in the guard  10  system, the machine or device may be allowed to restart. 
     As shown in  FIG. 6 , the exemplary flow diagram  90  depicts monitoring capacitance and making a determination of presence, as shown in first block  92 . A change in capacitance with respect to a guard  10  is monitored, such as by applying a charge to a capacitive component and monitoring the change in capacitance carried by the capacitive component, by the capacitive sensing module  20 . At block  94 , a determination is made as to whether a change in capacitance has satisfied a threshold amount. As discussed above, the change in capacitance indicates a change in voltage over a particular amount of time. At block  94 , a determination is made regarding whether the capacitance has changed by a threshold amount. If a determination is made that the capacitance has changed by a threshold amount (i.e., a particular amount of change in voltage has occurred within a particular window of time), then an indication is made that presence has been detected at block  96 , and the corresponding response is initiated at block  98 . As will be understood, blocks  96  and  98  may, in some embodiments, be combined into a single step of initiation of the corresponding response based on a determination of presence detection. At block  100 , if capacitance has not changed by a threshold amount, capacitance monitoring continues. 
     With reference to  FIG. 7 , capacitance detection  102  is shown on a display  104  that includes monitoring of capacitance  106  of a guard system  62 . Detection area  108  designates the indication of no contact being detected and also provides an indication of the inherent level of noise that is detected by the system. In some aspects, a guard system may adjust in response to a noise-based level of detection, such as area  108 . Further, detection area  110  includes peaks  112  and  114  corresponding to changes in capacitance relative to a baseline capacitance  116 , which indicate that human contact with the outer frame  12  or protective grid  14  has been detected. As discussed above, a threshold for detection may be determined, such that a minimal amount of contact, for a short period of time, may not trigger an indication of presence with respect to the frame. For example, a change in capacitance at or above a threshold change in capacitance relative to the baseline capacitance  116  may first require a threshold amount of capacitance change for a threshold amount of time before triggering a corresponding response. As stated above, detection of human contact with the frame, as indicated by peaks  112  and  114 , may trigger a number of outputs, such as stopping of a machine, alerting of an alarm feature, or any combination of features programmed to activate in response to the appropriate trigger. 
     Referring now to  FIG. 8 , an exemplary component  118  of a guard system is provided, including exemplary features of a computing device  120 , such as a memory  122 , a processor  124 , presentation components  126 , I/O ports  128 , I/O components  130 , and a power supply  132 . Computing device  120  is but one example of a suitable computing environment and is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the invention. Neither should the computing device  120  be interpreted as having any dependency or requirement relating to any one component or any combination of components illustrated. 
     Embodiments of the invention may be described in the general context of computer code or machine-useable instructions, including computer-useable or computer-executable instructions such as program modules, being executed by a computer or other machine, such as a personal data assistant or other handheld device. Generally, program modules include routines, programs, objects, components, data structures, and the like, and/or refer to code that performs particular tasks or implements particular abstract data types. Embodiments of the invention may be practiced in a variety of system configurations, including handheld devices, consumer electronics, general-purpose computers, more specialty computing devices, and the like. Embodiments of the invention may also be practiced in distributed computing environments where tasks are performed by remote-processing devices that are linked through a communications network, such as the exemplary network environment  156  of  FIG. 10  including a remote computing device  158 , a network  160 , and a capacitive sensing module  162 . 
     With continued reference to  FIG. 8 , one or more of the following devices may be directly or indirectly coupled, in association with computing device  120 , according to embodiments of the invention: memory  122 , one or more processors  124 , one or more presentation components  126 , one or more input/output (I/O) ports  128 , one or more I/O components  130 , and an illustrative power supply  132 . In embodiments, one or more busses may directly or indirectly couple one or more devices of the computing device  120 . Although the various blocks of  FIG. 8  are shown with borders for the sake of clarity, in reality, these blocks represent logical, not necessarily actual, components. For example, one may consider a presentation component such as a display device to be an I/O component. Also, processors have memory. The inventors hereof recognize that such is the nature of the art and reiterate that the diagram of  FIG. 8  is merely illustrative of an exemplary computing device that can be used in connection with one or more embodiments of the present invention. Distinction is not made between such categories as “workstation,” “server,” “laptop,” “handheld device,” etc., as all are contemplated within the scope of  FIG. 8  and reference to “computing device.” 
     The computing device  120  typically includes a variety of computer-readable media. Computer-readable media may be any available media that is accessible by the computing device  120  and includes both volatile and nonvolatile media, removable and non-removable media. Computer-readable media comprises computer storage media and communication media, computer storage media excluding signals per se. Computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVDs) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and that can be accessed by computing device  120 . 
     Communication media, on the other hand, embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared, and other wireless media. Combinations of any of the above should also be included within the scope of computer-readable media. 
     The memory  122  includes computer storage media in the form of volatile and/or nonvolatile memory. The memory  122  may be removable, non-removable, or a combination thereof. Exemplary hardware devices include solid-state memory, hard drives, optical-disc drives, and the like. The computing device  120  includes one or more processors  124  that read data from various entities such as the memory  122  or the I/O components  130 . The presentation component(s)  126  presents data indications to a user or other device. Exemplary presentation components  126  include a display device, speaker, printing component, vibrating component, and the like. 
     The I/O ports  128  allow the computing device  120  to be logically coupled to other devices including the I/O components  130 , some of which may be built in. Illustrative I/O components include a microphone; joystick; game pad; satellite dish; scanner; printer; wireless device; a controller, such as a stylus, a keyboard, and a mouse; a natural user interface (NUI); and the like. 
     Aspects of the subject matter described herein may be described in the general context of computer-executable instructions, such as program modules, being executed by a computing device  120 . Generally, program modules include routines, programs, objects, components, data structures, and so forth, which perform particular tasks or implement particular abstract data types. Aspects of the subject matter described herein may also be practiced in distributed computing environments where tasks are performed by remote-processing devices that are linked through a communications network, such as the network  160  of network environment  156  in  FIG. 10 . In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices. The exemplary network environment  156  may include a database configured to provide storage of and/or access to one or more items of data via the network  160 . 
     With reference to  FIG. 9 , an exemplary guard system component  134  for implementing embodiments of the present invention is shown. The guard system component  134  includes a capacitive sensing module  136  having a charge component  138 , a monitoring component  140 , a detection component  142 , a calibrating component  144 , a communication component  146 , a power source  148 , an alerting component  150 , an authentication component  152 , and a database  154 . It will be understood by those of ordinary skill in the art that the components and/or modules illustrated in  FIG. 9  are exemplary in nature and in number, and should not be construed as limiting. Any number of components and/or modules may be employed to achieve the functionality described herein. For example, any number of computing devices  120 / 158 , capacitive sensing modules  136 / 162 , and/or networks  160  may be employed by a guard system utilizing capacitive detection, within the scope of embodiments hereof. Further, components and/or modules may be located on any number of computing devices  120 / 158 . Each component and/or module may comprise a single device and/or interface or multiple devices and/or interfaces cooperating in a distributed environment. Further, multiple components and/or modules may include the various components of the capacitive sensing module  136  that collectively perform the tasks of embodiments of the invention. For example, multiple devices arranged in a distributed environment may collectively provide the charging, monitoring, detecting, calibrating, communicating, powering, alerting, authenticating, and/or storing functionality of a capacitive sensing module described herein. By way of example, the detection component  142 , features may be provided on a single server, a cluster of servers, or a computing device, such as the computing device  120 , remote from one or more of the remaining components of the capacitive sensing module. In some instances, the detection component  142  or at least a portion of components included therein, is provided at the computing device  120 . Other components and/or modules not shown may also be included within the guard system component  134 . 
     In some embodiments, one or more of the illustrated components and/or modules may be implemented as stand-alone applications. In further embodiments, one or more of the illustrated components and/or modules may be implemented via a computing device (e.g., the computing device  120 ), as an Internet-based service, and/or as a module within the capacitive sensing module  136 . The phrase “application” or “service” as used herein may broadly refer to any software, or portions of software, that runs on top of or accesses storage locations within a computing device  120  and/or multiple computing devices  120 . 
     It should be understood that this and other arrangements described herein are set forth only as examples. Other arrangements and elements (e.g., machines, interfaces, functions, orders, and/or groupings of functions) can be used in addition to, or instead of, those shown, and some elements may be omitted altogether. Further, many of the elements described herein are functional entities that may be implemented as discrete or distributed components or in conjunction with other components, and in any suitable combination and location. Various functions described herein as being performed by one or more entities may be carried out by hardware, firmware, and/or software. For instance, various functions, including the functions described below with respect to the capacitive sensing module  136 , may be carried out by a processor executing instructions stored in memory. 
     In some embodiments of the invention, a charge component  138  is configured to provide a charge to a capacitive component, such as a conductive outer frame  12  and/or protective grid  14 . The charge provided by charge component  138  may be any amount of charge required to provide a minimum amount of detectable change in capacitance with respect to an assembled guard system. As such, the charge component  138  may apply a particular amount of charge based on power received from an electrical power source, a battery power source, and/or other source required to provide a low voltage charge to the conductive components of a guard system, in accordance with embodiments of the invention. The charge component  138  may also be configured to change an amount of charge applied to a capacitive component over a particular period of time. For example, charge component  138  may apply charge to a capacitive guard system at a first threshold level, and in response to a change in a baseline level of background noise and/or a change in strength of applied charge with respect to the capacitive features of the guard system, the charge component  138  may provide more or less charge to the guard system to maintain a threshold amount of charge needed to enable detection. 
     Monitoring component  140  may be referred to as a receiving and/or measuring component that monitors an applied level of capacitive charge, as provided by the charge component  138 . In some aspects, the monitoring component  140  monitors a change in capacitance over time, with respect to a baseline level of applied charge to a capacitive component. The change in capacitance monitored may be assessed by the detection component  142  based on one or more criteria of the guard system. For example, a minimal change in capacitance with respect to a threshold level of expected and/or applied capacitance may be interpreted and/or identified by the detection component  142  as not indicating presence with respect to the guard system  62 . In that example, the minimal change in charge not indicating presence may be associated with a person temporarily coming into contact with the guard system  62 . As such, the detection component  142  may be used to prevent “false positive” results indicating that a temporary user presence is detected, but the content of the guarded internal area D (discussed above with respect to  FIG. 4 ) remains intact. 
     In some embodiments of the invention, the detection component  142  may be used to adjust to a particular environmental condition that interferes with the capacitance monitoring by monitoring component  140  and interrupts an accurate correlation between change in capacitance and determined presence. In one example, a guard system utilized in a warehouse may have a forklift moved next to the structure, which may interrupt the baseline level of capacitance detection by the capacitive sensing module  136 . As such, the detection component  142  may shift from a first level of detection to a second level of detection to compensate for the altered detection capabilities due to the presence of the forklift. In some aspects, a baseline for capacitance detection may be determined, and may be re-evaluated over time to account for a variety of external conditions during continued capacitance monitoring. As such, the detection component  142  may be configured as an adapting detection component  142 . 
     As will be understood, the calibrating component  144  may utilize a variety of filtering techniques to adjust the determinations made (regarding whether presence is or is not detected) using software associated with the processor. For example, a variety of filters or transforms may be applied to the monitored capacitance signal to adjust and/or adapt the software for a particular application or user. As such, a processor may be trained to alter the sensitivity of a threshold based on previous use by a particular user of a corresponding feature. Additionally, a reaction time may be changed and a threshold may be adjusted for different functions. In one embodiment of the invention, the calibrating component  144  may be used to configure a particular capacitive sensing module to a particular user&#39;s specifications. As such, a manufacturer may provide a guard system having a set of predetermined thresholds for capacitive detection. Upon installation, an end user may then utilize features of the calibrating component  144  to adjust particular features of the system for use when monitoring capacitance change associated with the installed guarding device. In some embodiments of the invention, the capacitive sensing module may reconfigurable to utilize in one of multiple different guard settings, such as a first capacitive component of a first guard enclosure, and a second capacitive component of a second guard enclosure. 
     The capacitive sensing module  136  may include a communication component  146 , such as a wired and/or wireless communication device configured to communicate at least one item of information to a recipient. For example, the communication component  146  may wirelessly provide a signal to a component coupled to the capacitive sensing module  136 , such as the wireless connection  78  between the second external component  82  and the capacitive sensing module  120  shown in the example of  FIG. 5A . In another aspect, a communication component  146  may include one or more wired features coupled one or more other devices for providing communicated information and/or data to or from the capacitive sensing module  136 . The communication component  146  may be used to provide information to a remote computing device  120  from one or more components and/or features of the capacitive sensing module  136 , such as communicating monitoring data from the monitoring component  140  to a remote computing device (e.g., a warehouse manager&#39;s computer). 
     The power source  148  feature of the capacitive sensing module  136 , as discussed with reference to the power source  16  in  FIG. 1 , may provide power to one or more components of the capacitive sensing module  136 . Without a power source  148 , at least one of the individual components and/or functions of the capacitive sensing module  136  may be disabled and/or interrupted. In some aspects, a primary power source  148  is provided to power the capacitive sensing module  136  components, while upon disruption to received power, a secondary power source  148  may be utilized. For example, the capacitive sensing module may include a battery backup feature configured to maintain at least one of the features of the capacitive sensing module during a temporary withdrawal of power, such as utilizing a battery backup as a secondary power source  148 . 
     An exemplary alerting component  150 , such as the audible alarm  24  of  FIG. 3 , may be coupled to the capacitive sensing module  136 , according to embodiments of the invention. The alerting component  150  may be any type of indicator and/or alert corresponding to an initiated response by the capacitive sensing module  136 . For example, the alerting component  150  may be a light alarm, an audible alarm, a vibrating alert, and text messaging alert, an emailing alert, and the like. In one embodiment, a capacitive sensing module may include a wireless component configured to connect to the internet, such as creating a connection over WiFi. As such, an alerting component  150  may be configured to automatically deliver a particular triggered alert and/or message to a particular user via an internet connection. In further aspects, an internect connection, either wireless or wired, between the capacitive sensing module and a remote computing device may be used to provide a notice to a first user that a second user is accessing an area protected by a guard system. 
     In some aspects of the invention, a capacitive sensing module  136  may be accessed by multiple users. As such, the authentication component  152  may determine whether a particular user is authorized access within the guard system  62 . In some aspects, the authentication component  152  may be used to assign user-specific access rights to one or more users of the guard system. The authentication component  152  may be used to apply one or more rules to the outputs generated and/or transmitted by the communication component  146 . For example, based on identifying a particular user attempting to access the interior of a guard system, the communication component may be utilized to communicate with one or more features of the capacitive sensing module  136  to either enable or disable the charge component  138  and either deny or permit access. As such, database  154  may be used to store one or more items of information accessed by the capacitive sensing module  136 , such as a look-up directory of users authorized to access the interior contents of the guard system. 
     In  FIG. 11 , a flow diagram  164  provides an example of capacitance monitoring utilizing an exemplary capacitive sensing module. At block  166 , a change in capacitance is monitored, which may include receiving capacitance monitoring data from one or more guards or portions of guards (outer frames, protective grids, bolts, vertical posts, etc.) via the capacitive sensing module. At block  168 , a change in capacitance is monitored with respect to a baseline level of noise, such as a minimal tolerated level of noise that does not trigger an indication of detection. For example, a change in capacitance monitored by the capacitive sensing module may result from a person attempting to open an assembled guard system. In other aspects, a monitored change in capacitance may result from a person in proximity to the assembled guard system that is not yet in contact with any of the guard panels. 
     In some embodiments, if the monitored capacitance has not changed by a threshold amount, an indication is generated to continue monitoring capacitance at block  170 . In further aspects, if a change in capacitance has satisfied a threshold amount (e.g., is greater than a predetermined level of noise that the system experiences but does not trigger an indication of presence and/or contact), a determination may be made regarding the capacitance change characteristics at block  172 . In one embodiment, one or more characteristics of a threshold change in capacitance (as determined at block  168 ) may be used to trigger an appropriate and/or corresponding response to such received indication of detection. For example, a capacitance change characteristic may include a combination of various different measurable indications associated with a received indication of capacitance that has satisfied a threshold amount of capacitance change, such as a duration of a detected change in capacitance, a timing of a detected change in capacitance, a combined indication of a user identity (e.g., via radio-frequency identification (RFID)) and attempted entry via an appropriate entry point (e.g., a door handle), and the like. In one embodiment, a duration of a capacitance change may be characterized at block  172  as being an instant change in capacitance (i.e., a touch by a user) and may further be characterized by a time of day when the instant change in capacitance is detected. As such, a user bumping into a capacitive feature of the guard system may signal a threshold change in capacitance (block  168 ) but may not necessarily prompt additional responses based on the associated time of day at block  172 . 
     At block  174 , a determination is made whether at least one of the capacitance change characteristics satisfies a detection threshold. If not, at block  180 , the system continues monitoring capacitance. If the capacitance change characteristics determined at block  172  satisfy one or more detection thresholds at block  174 , such as a duration/user identity/time of day detection threshold, the capacitance change is identified at block  176 . In some embodiments, the identifying of a capacitance change based on one or more satisfied detection thresholds may include comparing a list of authorized users to the identity of the user (via RFID detection) that has come into contact with the capacitive component of the guard system. For example, an authenticated entry protocol may be established for particular users that are permitted to access an area enclosed by a guard coupled to a capacitive sensing module. Such protocol may utilize processing at the capacitive sensing module and/or at a remote computing device to determine when and whether a particular user, identified by RFID, is permitted access to a particular area enclosed by a monitored guard.  144   
     At block  178 , a corresponding response is initiated for the identified capacitance change. 
     Referring finally to  FIG. 12 , exemplary capacitance detection  182  is shown, having a display  184 , a baseline  186 , and a capacitance measurement  188 . Further, as measured along an x-axis over time, the display  184  also includes a first portion  190 , a second portion  192 , a third portion  194 , a first non-detection portion  196 , a first detection portion  198 , a second non-detection portion  200 , a second detection portion  202 , a third non-detection portion  204 , a third detection portion  206 , and a fourth detection portion  208 . In embodiments of the invention, capacitance measurement  188  may be monitored over time in comparison to a baseline  186 . A minimal amount of change over time, such as that detected during the first portion  190  at the first non-detection portion  196 , may provide an indication of noise inherent to the capacitive component and/or the capacitive sensing module that does not trigger a corresponding response. Subsequently, at first detection portion  198 , a threshold change in capacitance is detected at or above a first threshold A, which may trigger a corresponding response (e.g., an alert, a warning buzzer, a text message to an authorized manager, etc.). 
     After the initial spike in detection at first detection portion  198 , during second portion  192  of monitoring, a second non-detection portion  200  may correspond to a gradual change in baseline  186  and corresponding shift in a tolerated level of noise by the capacitance monitoring. As such, the second threshold B is adjusted to provide an adjusted threshold level of change in capacitance with respect to the first threshold A. Similarly, in third portion  194 , a gradual increase in baseline  186  and corresponding capacitance measurement  188  may result in an altered threshold, such as the third threshold C, which both third detection portion  206  and fourth detection portion  208  satisfy. In further aspects, based on a level of capacitance measured within a portion of monitoring (i.e., within first, second, and third portions  190 ,  192 , and  194 ), the adjusted threshold requirements correspond to one or more additional factors that alter the capacitance of the guard system but do not directly correlate to a particular detection event. 
     A variety of detection events may be monitored for and/or tracked by the capacitive sensing module. In one aspect, a detection event may include receiving an indication of human contact with the guard system for a particular duration of time. For example, a change in capacitance between about 20-24 picofarads may indicate that human contact has been detected by the capacitive sensing module of a guard system, while in some embodiments, a threshold change in capacitance of at least 22 picofarads may be required before an indication of human detection is determined. A change in capacitance that is longer in duration may indicate that a user is leaning against the guard system in one embodiment, while in further embodiments, an instant change in capacitance may indicate a user manipulating a portion of the cage and/or attempting entry. In further aspects, a detection event may include a triggering of one or more corresponding features of the guard system based on a capacitance change of a particular threshold level of capacitance, over a particular threshold amount of time, from a particular user (e.g., a non-authorized user), at a particular time of day, etc. 
     In further embodiments, one or more determinations may be made by the capacitive sensing module, such as the determinations made with respect to the monitoring component and detection component described above with respect to  FIG. 9 . In some aspects, the satisfying of a threshold and/or triggering of an alert may be communicated to one or more locations via the communication component. For example, a triggered indication of unauthorized access may be sent via text message to a supervisor in charge of maintaining the integrity of the guard system. In further aspects, a log may be stored to characterize usage patterns and/or access information to the guard, such as monitoring which users enter the interior of the guard system and for what duration of time. The capacitive sensing module, either by a computing device coupled to the capacitive sensing module or via a remote computing device receiving information from the capacitive sensing module, may utilize both capacitive detection data and RFID information to determine particular user access trends and/or patterns over time. In further aspects, from a security standpoint, capacitance detection data may be combined with RFID technology to determine an identity of a person accessing an interior of a guard system prior to alerting a response that the guard system has been compromised. 
     From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth together with other advantages, which are obvious and which are inherent to the structure. 
     It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.