Abstract:
A personal voltage detection system comprises a garment to be worn by a user and carrying a plurality of electric field sensors each facing a different direction. Each sensor comprises a transducer sensing electric field in transmitting a wireless signal representing field strength for an associated direction. An alert device is in operative communication with the plurality of sensors and comprises a control configured to monitor field strength for each sensor and determine existence of an alarm condition responsive to field strength being above a pre-select level and to generate an alarm signal indicating the associated direction of the alarm condition.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority of Provisional Serial No. 621027,441, filed Jul. 22, 2014, and Appin. No. PCT/US15/39869, filed Jul. 10, 2015, the disclosures of which are hereby incorporated by reference in their entirety. 
     
    
     FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable. 
       MICROFICHE/COPYRIGHT REFERENCE 
       [0003]    Not Applicable. 
       FIELD 
       [0004]    This application relates to wearable electric field sensors and, more particularly, to a system that detects hazardous voltages and indicates direction of the source. 
       BACKGROUND 
       [0005]    Persons working in the vicinity of high voltage electrical fields must take precautions to maintain appropriate distance from the source of the high voltage. For example, workers around high voltage transmission lines must avoid coming too close to the lines. Also, first responders or the like who may be working in the vicinity of downed transmission lines must also avoid coming in contact with the lines. 
         [0006]    Existing wearable personal voltage detectors are directional and do not detect a voltage source which is not in the direction of the device. Normally, these devices are worn on the user&#39;s front at mid torso or on a belt clip, or the like. If the user is walking backwards or to the sides, the detector will not detect the voltage source as the human body stops the electric field from reaching the detector. 
         [0007]    Such existing personal voltage detectors are used for when the direction or location of the potential field is known. However, these devices cannot address the challenging needs and uncertain scenarios such as in a disaster rescue operation where the first responder is focused on rescue rather than potential electric hazards in the vicinity. 
         [0008]    Thus, it would be advantageous to have a system that can detect live electrical sources in multiple directions allowing the user to concentrate on the core work while ensuring the safety of the individual from dangerous voltage sources. 
       SUMMARY 
       [0009]    As described herein, a personal wearable system detects hazardous voltages surrounding the user for alerting industrial workers and indicating the direction of the source. 
         [0010]    There is disclosed in accordance with one aspect a personal voltage detection system comprising a plurality of wearable electric field sensors. Each sensor is adapted to be worn on an outer side of a user&#39;s body, each facing a different direction. Each sensor comprises a transducer sensing electric field and transmitting a wireless signal representing field strength for an associated direction. An alert device is in operative communication with the plurality of sensors and comprises a control configured to monitor field strength for each sensor. The alert device determines existence of an alarm condition responsive to field strength being above a preselect level and generates an alarm signal indicating the associate direction of the alarm condition. 
         [0011]    It is a feature that the alert device comprises an audio output generating an audio signal responsive to the alarm condition. 
         [0012]    It is another feature that the alert device comprises an indicator associated with each direction and the control illuminates the indicator for the associated direction of the alarm condition. 
         [0013]    It is yet another feature that the alert device may comprise a graphic display with the indicators for each direction. 
         [0014]    It is yet another feature that the alert device may comprise a Smartphone. 
         [0015]    It is still another feature that the alert device includes an indicator to indicate communication status with the plurality of sensors. 
         [0016]    It is still a further feature that the alert device comprises an indicator associated with each sensor and the control varies each indicator to indicate communication status for the associated sensor. 
         [0017]    It is still another feature that the sensors and the alert device communicate using short-wave length radio waves. 
         [0018]    It is an additional feature that the sensors and the alert device are battery powered. 
         [0019]    There is disclosed in accordance with another aspect, a personal voltage detection system comprising a garment to be worn by a user and carrying a plurality of electric field sensors each facing a different direction. Each sensor comprises a transducer sensing electric field in transmitting a wireless signal representing field strength for an associated direction. An alert device is in operative communication with the plurality of sensors and comprises a control configured to monitor field strength for each sensor and determine existence of an alarm condition responsive to field strength being above a pre-select level and to generate an alarm signal indicating the associated direction of the alarm condition, 
         [0020]    Other features and advantages will be apparent from a review of the entire specification, including the appended claims and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1 a    illustrates a personal voltage detection system as described herein; 
           [0022]      FIG. 1 b    illustrates a garment including a front, left and right electric field sensors; 
           [0023]      FIG. 1 c    illustrates the garment with a back electric field sensor; 
           [0024]      FIG. 2  is a block diagram of the electric field sensor; 
           [0025]      FIG. 3  is a flow diagram illustrating a program implemented in a microcontroller of  FIG. 2 ; 
           [0026]      FIG. 4  is a front view of an alert device used with the personal voltage detection system of  FIG. 1   a;    
           [0027]      FIG. 5  is a block diagram of a circuit for the alert device; 
           [0028]      FIG. 6  is a flow diagram illustrating a program in the microcontroller of  FIG. 5 ; and 
           [0029]      FIGS. 7-10  illustrate an alert device in the form of a Smartphone including a series of displays illustrating operation of an application program for the alert device. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]    A personal wearable system is described herein which detects hazardous voltages essentially 360° around the user for alerting a worker and indicating the direction of a hazardous voltage source. The system consists of four wearable electric field sensors embedded into a high visibility jacket or worn on an outer side of the body, one each of the front, back, left and right. Each sensor measures electric field strength and communicates to an alert device using short-wave length radio waves. The alert device, which may be a mobile phone, or other personal alert device, collects the data from each sensor, processes and generates an alarm with directional visual indication and an audio alert. 
         [0031]    Referring initially to  FIGS. 1 a , 1 b  and 1 c   , an exemplary garment  20  is in the form of a jacket. A front sensor  22 F, a back sensor  22 B, a left side sensor  22 L and a right side sensor  22 R are each embedded in the jacket  20 . As such, the front sensor  22 F senses an electric field in front of the user, the left sensor  22 L senses an electric field to a left side of the user, the back sensor  22 B senses an electric field in back of the user, and the right sensor  22 R senses an electric field to the right of the user. Each of the sensors  22 L,  22 R,  22 F and  22 B is identical in construction, other than having a unique address or identification code. Hereafter, each sensor may be described generically with the numeral  22 . Each of the sensors  22  communicates, as shown in  FIG. 1 a   , with a personal alert device  24  and/or a Smartphone  26 , configured as a personal alert module, using Bluetooth® technology (Bluetooth is a registered trademark of Bluetooth Sig, Inc.). 
         [0032]    The sensor  22  comprises a disk-shaped housing  30  including a push button  32  and LED  34 . An electrical circuit for the sensor  22  is illustrated in  FIG. 2 . The sensor  22  is powered by a coin cell battery  36 . A sensor antenna  38  is connected to a signal amplifier circuit  40 . The sensor antenna  38  may comprise a small conductive plate which acts as an antenna to pick up any voltage from an electrical field in front of the sensor and generates a low voltage signal in response to the electric field strength, as is known. The low voltage signal is amplified by the signal amplifier  40  and is then supplied to a band pass filter  42 . The band pass filter  42  is adapted to pass signals in the frequency band of 50 to 60 Hz corresponding to the typical power line frequencies. Thus, frequencies outside of this range are filtered out. The filtered signal is passed to a signal conditioning circuit  44  which develops appropriate analog signal levels input to a microcontroller  46 . The microcontroller  46  is also connected to the push button  32  and the LED  34 . Also, the microcontroller  46  is connected to a Bluetooth® transceiver  48 . The transceiver  48  transmits and receives wireless signals using short-wave length radio waves. As will be apparent, other communication technologies can also be used for wireless communications. Prior to use, the bush button  32  is depressed to pair the sensor  22  with the alert device  24 . The LED  34  confirms that the pairing is successful. 
         [0033]    The microcontroller  46  may take any known form and includes a processor and associated memory for operating the sensor  22  in accordance with a stored program. The microcontroller  46  is adapted to receive the amplified and filtered signal from the antenna  38  representing sensed field strength and periodically transmit the signal over the transceiver  48  to the personal alert device  24  or the Smartphone  26 . 
         [0034]    Referring to  FIG. 3 , a flow diagram illustrates a program implemented in the microcontroller  46  of  FIG. 2 . The program begins at a block  50  which wakes up the microcontroller  46  at a predetermined time interval, which in an illustrated embodiment is on the order of 200 ms. The microcontroller  46  then turns on power supply to other circuits at a block  52  and receives the signal representing measured field strength and converts the signal to a data format at a block  54 . The data is then transmitted to the alert device  24  or  26  at a block  56  using the transceiver  48 . The program then turns off power at a block  58  and goes into a deep sleep mode and then returns to the block  50  to wait for the next cycle. 
         [0035]    Referring to  FIG. 4 , the dedicated personal alert device  24  comprises a housing  100 . The housing  100  is sized and adapted to be worn by a user and may include a belt clip on a back side or the like. The housing  100  includes a front alert LED  102 F, a back alert LED  102 B, a right alert LED  102 R and a left alert LED  102 L. As such, such, there is an LED  102  associated with each sensor  22 . The housing  100  also supports a speaker  104 , an on/off button  106 , a pairing button  108 , a low battery LED  110  and a pairing LED  112 . 
         [0036]    Referring to  FIG. 5 , a block diagram illustrates a circuit for a control  114  in the housing  100 . The control  114  includes a microcontroller  116  in the form of a processor and associated memory for controlling operation of the personal alert device  24 . The circuit is powered by a nine Volt battery  118  connected to a power control logic circuit  120  which develops appropriate voltage signals for powering the other circuitry. The on/off switch  106  is connected to the power control logic circuit  120  for turning the device  24  on and off. A battery monitor circuit  122  is connected between the power control logic circuit  120  and the microcontroller  116 . The microcontroller  116  is also connected to the pairing button  108 , the LEDs  110  and  112  as well as the front LED  102 F, the left LED  102 L, the back LED  102 B and the right LED  102 R. Also, the microcontroller  116  is connected via a boost switching regulator  124  to the speaker  104 . Finally, the microcontroller  116  is connected to a Bluetooth® transceiver  126  for communication with the sensors  22 . 
         [0037]    As will be apparent, prior to initial usage it is necessary to pair the sensors  22  with the personal alert device  24 . This is done by depressing the pairing button  108  on the alert device  24  and the button  32  on each of the sensors  22 . Thereafter, this is also used to identify which of the sensors  22  is configured as the front, back, left and right sensors. This could be done, for example, by sequentially illuminating each of the LEDs  102 F,  102 L,  102 B and  102 R at the time each of the buttons on the individual sensors  22 F,  22 L,  22 B and  22 R is depressed. 
         [0038]    Additionally, each of the LEDs  102 F,  102 L,  102 B and  102 R can be multiple colors. For example, one color can be used to indicate an alarm condition. Another color can be used to indicate communication status for the associated sensor, as described below. 
         [0039]    Referring to  FIG. 6 , a flow diagram illustrates operation of a program implemented in the microcontroller  116  for detecting hazardous voltages and indicating direction of the source. The program begins at a block  130  which collects data for each sensor  22 . The data is converted into field strength at a block  132 . A block  134  sets a communication fail for any sensor which failed to send data. This can be used to illuminate one of the LEDs  102 , as described above. A block  134  sets a low battery LED for any sensor  22  whose battery voltage is below a threshold. This can be done by the color of the LED  102 . At a block  138 , the signal strength for each sensor  22  is compared to a reference level to determine if an alarm condition exists for the associated direction. If so, then the corresponding sensor LED  102  is turned on to a particular color if it is more than the threshold. Also, the audio alert is provided via the speaker  104  if there is an alarm condition. 
         [0040]    Thus, as described, the LEDs  102  can be used to indicate a communication failure, a low battery condition, or an alarm condition for an associated sensor  22  as well as identifying which of the four sensors the condition relates to. Particularly, any condition associated with the front sensor  22 F is indicated using the front LED  102 F. The same follows with the other directions. 
         [0041]    The personal alert device  24  described above comprises a dedicated device for use in the described system. Alternatively, a conventional Smartphone  26  can be used programmed with a detector application program, or app, for implementing the functionality of the alert device. Such an app would operate in accordance with the flow diagram of  FIG. 6 . 
         [0042]      FIG. 7  illustrates a home screen  200  on the smartphone  26  including an icon  202  for the detector app.  FIG. 7  illustrates a graphic display  204  for selecting various detection operations. As will be appreciated, the smartphone  26  can be used for additional alert functions, including the voltage detector function, indicated by a button  206 , which is used to discover the various sensors.  FIG. 9  illustrates a display screen  208  showing that the voltage detection function is on. Also, the display uses indicators of a particular color according to the status, such as using the color green to indicate that all sensors are active. The color associated with the particular sensor could change, for example, to gray if there is a communication failure.  FIG. 10  illustrates a display screen  210 , similar to that in  FIG. 9 , in which an audio alert is given, represented by  212 , with an alarm condition and a screen showing directional detail by the left indicator turning to red. There is also a button  214  which allows a user to mute the alarm for a preselect time, such as one minute, and a button  216  to toggle a vibration function. Otherwise, the app operates in accordance with the program illustrated in  FIG. 6  and described above. 
         [0043]    Thus, the illustrated system comprises two components. The first is a jacket embedded with four sensors as well as the personal alert device. Each sensor comprises an ultra low power sensor powered using a coin cell battery and senses electric field and converts it to digital data for transmission to a master device. The sensor uses a field sensing antenna connected to a signal conditioning circuit provided to a microcontroller where it is converted to digital data to be sent to the master. The master alert device can be a dedicated device or a mobile phone, either configured with Bluetooth® transceivers. Either alert device runs an application program which pairs with each sensor and collects the information, including current field strength, battery status, RSSI, and IDD details from each sensor. The alert device processes the collected raw information from each sensor and generates the audio alarm and illuminates the corresponding directional LEDs when an alarm condition is found to exist. 
         [0044]    Thus, the system provides omni-directional protection and thus provides increased safety for the user. The system does so by showing the direction of the live voltage source and comprises a hands free system allowing the user to concentrate on the work at hand. Additionally, the system provides the user with multiple modes of alert, comprising an audio signal, vibration and visual indication. Further, when used with a Smartphone, the data can be communicated to a supervisor at a central station for further analysis and decision making. 
         [0045]    It will be appreciated by those skilled in the art that there are many possible modifications to be made to the specific forms of the features and components of the disclosed embodiments while keeping within the spirit of the concepts disclosed herein. Accordingly, no limitations to the specific forms of the embodiments disclosed herein should be read into the claims unless expressly recited in the claims. Although a few embodiments have been described in detail above, other modifications are possible. For example, the logic flows depicted in the figures do not require the particular order shown, or sequential order, to achieve desirable results. Other steps may be provided, or steps may be eliminated, from the described flows, and other components may be added to, or removed from, the described systems. Other embodiments may be within the scope of the following claims. 
         [0046]    The present system and method have been described with respect to flowcharts and block diagrams. It will be understood that each block of the flowchart and block diagrams can be implemented by computer program instructions. These program instructions may be provided to a processor to produce a machine, such that the instructions which execute on the processor create means for implementing the functions specified in the blocks. The computer program instructions may be executed by a processor to cause a series of operational steps to be performed by the processor to produce a computer implemented process such that the instructions which execute on the processor provide steps for implementing the functions specified in the blocks. Accordingly, the illustrations support combinations of means for performing a specified function and combinations of steps for performing the specified functions. It will also be understood that each block and combination of blocks can be implemented by special purpose hardware-based systems which perform the specified functions or steps, or combinations of special purpose hardware and computer instructions. None of the methods according to various aspects disclosed herein is limited to performing the steps thereof in any particular order.