Patent Publication Number: US-2017368443-A1

Title: Fencing scoring system

Description:
TECHNICAL FIELD 
     The present disclosure relates to systems used to score fencing matches. 
     BACKGROUND 
     Sport fencing is scored using an electronic hit recognition system. The system requires a reel of insulated conductive cabling to be attached to the fencer&#39;s jacket. The reel is automatically retracted as the fencers move about the piste or strip. The cabling is energized to conduct electricity when a fencer is hit and a point is scored. Use of the cabling can reduce fencer mobility, require high energy consumption, and require substantial investment to acquire. 
     SUMMARY 
     A fencing scoring system may include a controller configured to output a signal indicative of a hit. The output signal may be in response to counts of edges of one or more oscillating signals having a variable frequency deviating from a threshold over a period. The counts may be of edges that are rising. The counts may be of edges that are falling. The counts may be of edges that are rising and falling. The frequency may be based on a capacitance of a circuit. A portion of the capacitance may be from a fencing equipment component. The equipment component may be a lamé. The equipment component may be a weapon. 
     A fencing scoring system may include a mobile device configured to record an indication of a hit. The recordation may be in response to a signal from a circuit connected to a port of the mobile device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts fencers on a piste and a scoring station; 
         FIG. 2  depicts an oscillating circuit diagram that oscillates based on an RC time constant; 
         FIG. 3  depicts an oscillating circuit diagram that includes two capacitors and a pushbutton switch; 
         FIG. 4  depicts an oscillating circuit diagram that includes three capacitors and a pushbutton switch; 
         FIG. 5  depicts a scoring system having an oscillating circuit and a mobile device; 
         FIG. 6  depicts a scoring system having an oscillating circuit, an isolation coupler, and a microcontroller; 
         FIG. 7  is a graph of an oscilloscope of a baseline oscillating signal; 
         FIG. 8  is a graph of an oscilloscope of an oscillating signal after the pushbutton switch is closed; 
         FIG. 9  is a graph of an oscilloscope of an oscillating signal after a pushbutton switch is closed and contact has been made with a target area; and 
         FIG. 10  is a screenshot of a mobile device application that counts the number of rising edges to determine a frequency and hit. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples, other embodiments may take various, and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations. 
     The sport of fencing is an adaptation of medieval swordplay. Fencers attempt to score points by landing attacks on various target areas, which are scored as a hit or touch. In the 1900&#39;s fencing became an Olympic sport, and the matches were judged by a referee. This referee would visually interpret the actions of the duel and assign valid points to either fencer. 
     An electronic scoring system may be used to determine hits. Use of an electronic system may still task a referee with awarding points in accordance with the rules of the sport. Fencers wear metallic, conductive jackets in order to detect electrical signals emitted from respective weapons to determine when a valid hit has been made. In foil and épée, a push button switch is attached at the end of each weapon to detect hits above a threshold force. In sabre, contact between the sabre weapon and a lamé determines hits. 
     Some electronic systems are expensive, cumbersome, and unreliable. A scoring system may be used to detect hits and communicate between devices associated with the fencers and referee. Proper configuration of a hit detection circuit may lead to a smaller form factor, increased accuracy, and lower cost. 
     Instead of direct electrical connection from each of the fencers to a scoring station, wireless communications may be used to disseminate hits. A wireless transceiver may be used to communicate match status information with an opponent&#39;s scoring system or a scoring station. For example, the fencer&#39;s system may constantly push information to various listening devices to report equipment status information. The equipment status information reported may be rolling lamé, weapon, and sequence or timing information. Depending on the wireless protocol used, rolling, continuous information may increase system response times and data integrity. The transmitting transceiver may send empty or non-hit data packets to maintain communication continuity and adjust the data packet to indicate a particular type of hit or circumstance. 
     In at least one embodiment, two scoring systems are used. Each fencer has a scoring system with multiple inputs and at least one transceiver. Each of the transceivers communicates with one another to arbitrate hits. Whenever contact is recognized from the fencing equipment, each transceiver provides an indication of the hit. The hit may be indicative of either the fencer&#39;s score or the opponent&#39;s score. For example, if Fencer A lands a touch on Fencer B, a signal is transmitted from Fencer A to Fencer B, indicating a hit with the weapon. In addition, a signal may be transmitted from Fencer B to Fencer A, indicating a hit received by Fencer B&#39;s lamé. After an indication of a hit, a separate process may run on either fencer&#39;s system with a window, allowing Fencer B an opportunity to counter hit. The window may be 50-240 ms depending on the weapon used. After this period, fencer B will not be able to score any hits, and the score system display may disable any lights activated from this point on. 
     The transceivers may be Bluetooth® type. The Bluetooth® transceivers may pair with one another as part of a match initialization procedure. The pairing process may require unique pins or IDs to be used to maintain data integrity and confidentiality. 
     In another embodiment, three scoring systems are used. Each fencer has a scoring system, and the scoring station has a scoring system. Each of the systems may be configured to have a Bluetooth® transceiver. The Bluetooth® transceivers may pair with one another as part of a match initialization procedure. Different unique user identification numbers may be required for each of the Bluetooth® devices involved in the pairing. Each fencer&#39;s scoring system transmits score information to the scoring station for visual and aural indication. The system may include any number of wireless transceivers and interconnected transceivers for hit arbitration and scoring. The scoring station may act as a display for the referees or an intermediary for the fencers&#39; scoring systems. The scoring station may receive indication of points from each side and arbitrate the time delay for a hit or ensure each weapon hit is coupled with a lamé hit when required. 
     The Bluetooth® transceivers may be directly paired with the scoring station. The scoring station may communicate hits to each fencer&#39;s scoring system and act as an intermediary. The scoring system may act as an intermediary to prevent cheating or ensure system continuity. 
     An important facet of the fencing scoring system is hit sensing. Hit sensing is weapon and equipment specific. With a foil and épée, a hit may be scored only by depression of a push button switch on the tip of the blade. Contact with the side of the blade does not result in a score. A force above a regulated value must be used to depress the switch. The regulated value is different for the foil and the épée. A hit may be required to land within a target area. The target area may be established by a lamé. With a sabre, a hit may be scored when the blade contacts a lamé. A sabre may contact the lamé at any angle and a predetermined pressure is not required. 
     With a foil and épée, a sensing circuit may be used to recognize a depression of the push button switch. Closure of the switch may allow or impede the flow of electrons through the weapon. Closure may also change the electrical characteristics of the circuit. For example, a closed switch may include or remove capacitance from the circuit. The circuit may be an RC circuit. An adjustment to the capacitance of the circuit may change the frequency of the signal. Measurement of the signal frequency may provide an indication of a switch closure or a hit. In fencing, the hit must occur in the target area. The target area for épée fencing is the opponent&#39;s entire body. The target area for foil fencing is the opponent&#39;s lamé. The frequency sensing method can also determine contact with an opponent&#39;s lamé, the target area, or a non-target area because contact with a lamé further changes the capacitance of the circuit. The change in circuit capacitance alters the frequency of an oscillating signal of the weapon or lamé. The changes in frequency may be detected to identify hits in both the target area and the non-target area. 
     An operational amplifier may drive the oscillating signal. A change in the oscillating signal may signify a hit. The amplifier may be a relaxation type operational amplifier. The circuit may have a baseline capacitance and resistance selected to provide a baseline oscillation frequency. The relaxation type operational amplifier may be configured to raise or lower the frequency based on increased or decreased capacitance. The change in capacitance may be caused by a toggling of the push button switch, which is configured to engage or disengage one capacitor in the circuit. The change in capacitance may be caused by a capacitance of weapon changing after contact with the lamé is made. The change in capacitance may also be caused by a capacitance of the lamé changing after contact from a weapon. In all of these circumstances, the capacitance of the circuit is changed and the output frequency of the circuit is correspondingly modified. 
     A 555 timer may be used to drive the oscillating signal as well. The circuit may similarly have a baseline capacitance and resistance selected to provide a baseline oscillation frequency. The 555 timer may be configured to raise or lower the frequency based on increased or decreased capacitance associated with input pins. The capacitance may be tied to the lamé, weapon, or pushbutton of the weapon. 
     The scoring system may include multiple oscillators and sensing leads to properly score the game. For example, individual or combination circuits may be connected to the lamé and weapon to provide score information for and against the fencer. The presence of multiple oscillating circuits on an individual board may cause unwanted capacitive coupling. The capacitive coupling of multiple oscillating circuits may distort the waveform, impeding accurate hit detection. To prevent capacitive coupling, opto-couplers or opto-isolators may provide electric field isolation between channels. The opto-coupling may include light-emitting diodes and photo-resistors to opto-couple the oscillator circuit and a microcontroller. 
     A microcontroller may be used to determine a hit. For example, a PIC® microcontroller may be used. The microcontroller may have multiple inputs for receiving an oscillating signal or a converted signal based on the oscillating signal. The microcontroller may process the input to determine whether a hit has been made. 
     In one example, the microcontroller may receive the oscillating signal from the oscillator circuit. The microcontroller may be configured to count the number of rising edges, falling edges, or a combination thereof. Some oscillating signals may have a squared shape (e.g., square wave). Other oscillating signals may have a rounded shape (e.g., sinusoidal wave). Any type of oscillating wave may be measured by the rising or falling edges to determine a count. The count may reset at the beginning of each measurement window or period. The period may be 1 ms. If the number of counts overruns the count register or buffer, the microcontroller may adjust the measurement period to accurately measure counts. If the number of counts is below a threshold (e.g., 10) the measurement period may be extended. 
     The oscillating signal may be conditioned prior to receipt by the microcontroller. For example, a frequency to voltage converter may be used to convert the frequency of the oscillating signal to a voltage. The microcontroller&#39;s analog input may receive the voltage. Other signal conditioners or converters may be employed to alter the oscillating signal. 
     Mobile devices may be used in combination or as a replacement to the controller. A mobile device may be configured to receive an oscillating or converted oscillating signal to determine a hit. For example, the headphone jack, having a microphone port, of a mobile phone may be used to receive an oscillating signal and determine a hit. Any mobile device port may be used to receive the oscillating or converted signal to determine a hit using application software on the mobile device. For example, the waveforms received by the microphone jack may be digitally recorded by the android device. Using digital signal processing, the frequency of the output can be measured by the processer. The processor may count the rising and falling edges of the oscillating signal to determine the frequency. The frequency or counts are then compared with a threshold to determine the weapon or lamé state. The sample rate of the digital signal processor on mobile phones may be limited to an audible range. The sample rate may be maximized to the maximum capability of the digital signal processor to improve hit detection. Devices in the future may have improved digital signal processing capabilities, which will provide improved hit detection. Mobile devices, as used in this application, are not limited to mobile phones. Any mobile electronic device may be used. The device may have a screen for displaying match information. 
     Mobile devices may be interconnected to communicate hits and activate delay timers. The mobile devices may connect using any enabled wired or wireless medium. Mobile devices may communicate via any networking protocol, method, or medium (e.g., Ethernet networks, ad-hoc networks, paired Bluetooth® connections, NFC connections). The mobile devices may connect on demand or continuously share data packets. 
     The mobile device may include a display to communicate the match score. The display may be organized similar to traditional fencing scoring systems. The mobile device may have indicators to display hits or touches to the respective lamé or weapon. The mobile device may track the match score. Each point may be associated with a table indicating the time of each respective hit and whether a counter hit was detected. 
     Now referring to  FIG. 1 , fencers  100 ,  120  are shown. Each fencer  100 ,  120  has a weapon  102 ,  122 . The weapons  102 ,  122  may be a foil, épée, or sabre. The weapons  102 ,  122  include blades  104 ,  124 . The weapons  102 ,  122  may also include pushbutton switches  105 ,  125 . The weapons  102 ,  122  may include guards  106 ,  126 . The fencers  100 ,  120  may wear masks  108 ,  128 . The fencers  100 ,  120  may also wear lamés  110 ,  130 . Cables  112 ,  132  are attached to the lamés  110 ,  130  and the weapons  102 ,  122 . The cables may be attached to circuitry at each weapon  152 ,  162 . The cables attach the fencing equipment to a scoring system or systems  150 ,  160 . The scoring apparatus includes lights  142 ,  144  to indicate hits or touches and counters  146 ,  148  to tally points. The scoring station  140  may include a scoring system  164 . All of the scoring systems  150 ,  160 ,  164  may be in wired or wireless communication. Each fencer may have more or less scoring systems than are shown. The scoring systems may be located in each of the weapons. Each fencer may have a scoring system on the weapon and lamé that communicate. Any configuration of wired or wireless devices may provide adequate scoring. 
     Now referring to  FIG. 2 , an oscillating circuit  200  is shown. The oscillating circuit includes an operational amplifier  202 . Any type of operational amplifier or oscillating circuit may be used. The system as shown may produce a wave with hard edges. Any type of wave generator, however, may be used, including sinusoid. The circuit has resistors R 1    208 , R 2    206 , and R 3    204 . The circuit also includes a capacitor, C 1    210 . The circuit has a ground  212  and a voltage source, as shown. The circuit has an output  214 . The frequency of the output is related to the capacitance of C 1    210  and the resistance of R 3    204 . Equation 1 discloses the relationship. 
     
       
         
           
             
               
                 
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     Now referring to  FIG. 3 , an oscillating circuit  300  is shown. The oscillating circuit includes an operational amplifier  302 . The circuit has resistors R 1    308 , R 2    306 , and R 3    304 . The circuit also includes a capacitor, C 1    310 . The circuit has a ground  316  and a voltage source, as shown. The circuit also includes an additional capacitor, C 2    312 . A bypass switch  314  is configured in parallel with C 2    312 . The bypass switch  314  may be attached to the weapon as discussed above. The bypass switch  314  may be the pushbutton switch on the foil or épée. The bypass switch  314  is activated when the pushbutton is depressed or released. The bypass switch  314  controls the capacitance of the circuit, resulting in varying output frequencies at output  318 . 
     Now referring to  FIG. 4 , an oscillating circuit  400  is shown. The oscillating circuit includes an operational amplifier  402 . The circuit has resistors R 1    408 , R 2    406 , and R 3    404 . The circuit also includes a capacitor, C 1    410 . The circuit has a ground  416  and a voltage source, as shown. The circuit also includes an additional capacitor, C 2    412 . A bypass switch  414  is configured in parallel with C 2    412 . As shown, an additional capacitor, C 3    416 , is connected to the circuit. C 3    416  is introduced when the weapon hits the lamé of the opponent, providing capacitive touch sensing. C 3    416  is introduced because of capacitive coupling between the weapon and the lamé, clothing, or other material. The capacitance of C 3    416  depends on the material touched, allowing the touch to be distinguished between the lamé and other not scoring contact. For example, C 3    416  may have a capacitance of 50 μF when the weapon touches the opponents lamé. C 3    416  may have a capacitance of 10 μF when the weapon touches a piece of clothing. In order to distinguish between contact with the fencer&#39;s own lamé, each lamé may be made from different materials. The oscillating circuit  400  discloses a method to vary the frequency of the oscillating signal, depending on particular fencing scoring opportunities. 
     Now referring to  FIG. 5 , an oscillating circuit  500  is shown. The oscillating circuit includes an operational amplifier  502 . The circuit has resistors R 1    508 , R 2    506 , and R 3    504 . The circuit also includes a capacitor, C 1    510 . The circuit has a ground  516  and a voltage source, as shown. The circuit also includes an additional capacitor, C 2    512 . A bypass switch  514  is configured in parallel with C 2    512 . As shown, an additional capacitor, C 3    516 , is connected to the circuit. C 3    516  is introduced when the weapon hits the lamé of the opponent, providing capacitive touch sensing. C 3    516  is introduced because of capacitive coupling between the weapon and the lamé or clothing. In one embodiment, the frequency signal may be directly connected to the microphone jack  524  of the mobile device  526 . The microphone jack  524  may receive a signal for digital signal processing by the mobile device  526  within the mobile device. In another embodiment, the signal may be conditioned or converted to a voltage using a frequency to voltage converter  522  first. The frequency to voltage converter  522  may alleviate latency issues caused by the digital signal processor of the mobile device. The mobile device may include display software and score tracking to manage the match. 
     Now referring to  FIG. 6 , a scoring system  600  is shown. The scoring system has two oscillating circuits  601 ,  621 . The oscillating circuits are based on a 555 timer. Although shown as separate chips, the 555 timers  602 ,  622  may be combined with a 556 or 558 timer. Each of the oscillating circuits  601 ,  621  have independent power supplies  604 ,  624  and grounds  610 ,  630 . An RC time constant is created based on resistors R 9    606 , R 10   626 , and capacitors C 9    608  and C 10    628 . The capacitance of the circuit may be adjusted by a similar circuit configuration as disclosed in  FIG. 5 . Control capacitors  612 ,  632  are also included to ensure proper triggering of the oscillating signal and provide a buffer from noise. 
     The oscillating signal outputs are isolated from capacitive couple on the circuit board by opto-couplers  614 ,  634 . The opto-couplers  614 ,  634  may be independent chips. The output of the opto-couplers  614 ,  634  are fed into the microcontroller  616 , which can process both signals for hit recognition. The microcontroller  616  may operate similar to the mobile device as specified above. The microcontroller  616  is configured to receive either a frequency or voltage. The controller  616  can measure frequency of the oscillating signal in a variety of ways. The controller  616  may count edges of the oscillating signal within a period to determine the frequency of the signal. The controller  616  may store the counts in a register  617  that is reset at the beginning of each period by a timer. A data packet may be transferred from the micro controller  616  to a Bluetooth® transceiver  618 . The data packet may include sequence, hit, and score information. The transceiver  618  includes an antenna  620  to propagate electromagnetic waves for communication. 
     Now referring to  FIG. 7 , a scope diagram  700  of an oscillating signal  706  is shown. The oscillating signal has rising or leading edges  702  and trailing or falling edges  704 . The frequency of the signal is about 3.0 kHz. The frequency of the signal is determined by the capacitance and resistance of the oscillating circuits as described above. The frequency of the oscillating signal  706  may be determined by measuring the edges  704 ,  706  over a period. The oscillating signal  706  may be displayed as voltage  710  over time  708 . As an example, this waveform may be created when the pushbutton is not depressed and contact has not been made. This baseline frequency may be adjusted to meet performance requirements. 
     Now referring to  FIG. 8 , a scope diagram  800  of an oscillating signal  806  is shown. The oscillating signal has rising or leading edges  802  and trailing or falling edges  804 . The frequency of the signal is about 10.0 kHz. The frequency of the signal is determined by the capacitance and resistance of the oscillating circuits as described above. The frequency of the oscillating signal  806  may be determined by measuring the edges  804 ,  806  over a period. The oscillating signal  806  may be displayed as voltage  810  over time  808 . As an example, this waveform may be created when the pushbutton is depressed and contact has not been made with the target area or lamé. 
     Now referring to  FIG. 9 , a scope diagram  900  of an oscillating signal  906  is shown. The oscillating signal has a rising or leading edges  902  and trailing or falling edges  904 . The frequency of the signal is about 9.0 kHz. The frequency of the signal is determined by the capacitance and resistance of the oscillating circuits as described above. The frequency of the oscillating signal  906  may be determined by measuring the edges  904 ,  906  over a period. The oscillating signal  906  may be displayed as voltage  910  over time  908 . As an example, this waveform may be created when the pushbutton is depressed and contact has been made. 
     Now referring to  FIG. 10 , a screenshot  1000  of the frequency recognition algorithm is shown. An example system was configured to receive a waveform with peaks at positive 2.5 V and negative 2.5 V. The oscillating signal was received at the mobile device. An Android® system was used, but any mobile device may be used, including special circuitry designed with the purpose of recognizing hits. The oscillating signal was sent to the microphone input of the Android® device which includes a 14-bit analog to digital converter (ADC). The sampling rate of the ADC was set to 22.1 kHz. Whenever the sign of the signal changes, the algorithm would increment a counter by one. Meaning, the algorithm counts the number of edges over a period  1002 ,  1008 , and displays outputs  1004 ,  1006  with the resulting hit determination. The displayed data in sections  1004 ,  1006  are only a handful of the counts that would be ordinarily captured. As shown, the counts in section  1008  are slower, which indicate a valid hit. Section  1002  is shown as a 9.1 kHz signal and section  1008  is shown as an 8.3 kHz signal. These correspond to an off target or insulator hit and an on target or lamé hit, respectively. 
     The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments may be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics may be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes may include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for particular applications.