The modern sport of fencing is hundreds of years old. Historically, referees and bout directors awarded points (or touches—where one opponent's weapon blade or tip makes contact with the target area of the other opponent) by visually observing two opponents and determining whether a touch occurred and whether the fencer scoring the touch should be awarded a point based on existing rules. The object of saber fencing, based on cavalry fencing on horseback, is to score touches by contacting a blade or tip of a fencer's weapon with an opponent's target area (above that opponent's waist including his arms and head). The object of foil fencing is to score touches by contacting the tip of a fencer's weapon with an opponent's target area (the opponent's torso). The object of epee fencing, based on first-blood duels, is to score touches by contacting the tip of a fencer's weapon with an opponent's target area (any part of the opponent's body). Each form of modern sport of fencing is very rapid. Often actions, contacts, and target areas are difficult to visually see. Modern fencing weapons are so light that skilled fencers can manipulate them with extreme speed in flurries of action. This speed renders it difficult to determine when touches are scored. Even where several officials are employed to judge a match, visual identification of scoring maneuvers is difficult. Disagreement between officials often occurs, due to the inconsistency in the quality of perspective enjoyed by the various officials. Moreover, judgment by visual observation is a subjective criterion, and the acuity of vision may vary among officials, and even in the same official.
In the 1970s electronic circuits were used to aid in awarding touches.
Foil fencing includes a similar configuration to the saber configuration of
Epee fencing includes a similar configuration to the saber configuration of
A problem associated with the state of the art fencing system is that it requires jackets, vests and masks made of conductive fabrics and materials which do not wear well with sweat or frequent washing. They are constricting to wear and inhibit a fencer's maneuverability and motion. Often fencers have to wear multiple jackets for safety reasons and the conductive garments are an additional layer which can be uncomfortable and hot for fencers who are exerting themselves. Further, fencers are required to be connected to wires such as the cords in their sleeves, reel wires 24, 26, and mask wire 31 which frequently break and easily become tangled and uncomfortable. Additionally, if the equipment fails to connect a circuit in the proper way due to oxidation of a weapon blade or tip or a conductive garment, target area connectivity dead spots, an overabundance of sweat, a malfunction of wire, or the electrical connection anywhere between electrical scoring apparatus 10 weapon 12, 14 all can affect the outcome of a match and cause for difficulty in scoring a bout. The circuitry used in current state of the art fencing scoring systems is somewhat unreliable and scoring equipment is prone to malfunction, leading to inaccurate scoring results and lengthy downtime while the fencer attempts to “fix” any malfunctioning fencing equipment. Additionally, fencing equipment can be quite costly as simply to engage in electrical scoring a pair of fencers requires electrical scoring apparatus 10, two reels 28, 30, two electrical wires connecting reels 28, 30 to electrical scoring apparatus 10, wires in fencers' sleeves, etc which can cost thousands of dollars.
Contact sensing probes are used in industry to detect capacitance of non-conductive materials such as textiles. Capacitive sensors measure capacitance by contact and non-contact techniques. Non-contact sensors measure disruption in capacitive electron flow. Contact capacitive sensors detect capacitance changes when a lead contacts a surface. Contact capacitive sensors can detect different material properties of the surface they contact. For example, contacting a metal material versus a non-conductive material, or contacting concrete versus plaster. Capacitive sensors can also distinguish between various kinds of textiles based on their relatively unique resistivity.
Capacitance describes how the space between two conductors affects an electric field between them. If two metal plates are placed with a gap between them and a voltage is applied to one of the plates, an electric field will exist between the plates. This electric field is the result of the difference between electric charges that are stored on the surfaces of the plates. Capacitance refers to the “capacity” of the two plates to hold this charge. In single probe sensing, a conductive probe contacts a surface. A sensor measures changes in current across a resistor connected to the probe to determine the dielectric constant of the contacted surface. The sensing surface of the probe is the electrified plate and what you're measuring is the target. Capacitive sensors can be very effective in measuring presence, density, thickness, and location of non-conductors as well. Non-conductive materials like plastic have a different dielectric constant than air. The dielectric constant determines how a non-conductive material affects capacitance between two conductors. When a non-conductor is inserted between the probe and a stationary reference target, such as the human body, the sensing field passes through the material to the grounded target. The presence of the non-conductive material changes the dielectric and therefore changes the capacitance. The capacitance will change in relationship to the thickness and density of the material.
The invention overcomes the problems of the prior art by providing a contact sensing device and system which embodies all the required sensing components in a handheld device and does not require conductive contact surfaces to detect contact with a target area. The invention is also entirely self-contained and requires no additional wiring to be connected outside the personal system. In the fencing system example, this will remarkably increase the system reliability, the fencer's comfort and maneuverability, and reduce the cost and quantify of equipment subject to malfunction and repair needed in the prior art system.
The invention achieves this in a first aspect by a handheld device for sensing contact with a substance which includes a capacitive sensor that includes an elongate portion configured to generate at least one sense signal upon said elongate portion contacting at least one substance; a processor for receiving the sense signal from the capacitive sensor, processing the at least one sense signal to determine a property of the at least one substance, and for generating an indicator signal; and an indicator which receives the indicator signal and indicates if the capacitive sensor contacts the substance.
In one embodiment a portion of the elongate portion of the capacitive sensor includes a contact sensing lead for sensing contact between a lateral side of a portion of the elongate portion and the at least one substance.
In another embodiment, the elongate portion is a blade or tip of a fencing weapon.
In another embodiment the device includes a plurality of indicators and the processor determines which indicator or indicators receives an indicator signal based on the determined property of the at least one substance. The processor can contain logic for determining which of the plurality of indicators receives an indicator signal.
In one embodiment, the property of the at least one substance is a material characteristic. In another embodiment, the property of the at least one substance is conductivity. In another embodiment the property of the at least one substance represents contact on a target area. The processor can also send an indicator signal to one of the plurality of indicators if the capacitive sensor contacts the target area and the processor sends an indicator signal another of the plurality of indicators if the capacitive sensor contacts an area other than the target area.
In another embodiment, the property of the at least one substance is the presence of another device. The processor can be configured to send an indicator signal to one of the plurality of indicators if the capacitive sensor detects the presence of another device.
In another embodiment, the device includes at least one motion sensor for sensing motion of the device. The motion sensor can sense acceleration, speed, and/or direction. The motion sensor can send a motion signal to the processor and the processor processes the motion signal to generate a motion indicator signal.
In one embodiment, the device includes a counter for outputting a count of indicator signals and a memory for storing said count. In still another embodiment, the device includes a display for displaying the count.
In one embodiment, the device includes a power source. In another embodiment the device includes a wireless communication device for transmitting at least one of the indicator signal and the motion indicator signal. The wireless communication device can also receive at least one indicator signal from at least one other device.
In one aspect the invention includes a system for scoring contact between a device and at least one substance including: at least one device for sensing contact with a substance that includes a device for sensing contact with a substance which includes a capacitive sensor that includes an elongate portion configured to generate at least one sense signal upon said elongate portion contacting at least one substance; a processor for receiving the sense signal from the capacitive sensor, processing the at least one sense signal to determine a property of the at least one substance, and for generating an indicator signal; and an indicator which receives the indicator signal and indicates if the capacitive sensor contacts the substance and at least one target comprising at least one substance detectible by the device.
In one embodiment the system includes at least two devices for sensing contact. In another embodiment the two devices communicate wirelessly.
Other aspects and advantages of embodiments of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrated by way of example of the principles of the invention.
A saber 12 as depicted in
Additionally, processor 40 can signal wireless device 43 to transmit a signal indicating a valid touch to an electrical scoring device which will then cause a respective appropriate indicator light to illuminate. Wireless device 43 can be any wireless device known to one of skill in the art, such as an IEEE 802.11 compliant device, or a Bluetooth device. Further processor 40 can signal wireless device 43 to transmit a signal intended for receipt by an opponent's saber. This information can be used to signal an indicator on the opponent's weapon. It can also be transmitted with the output of a motion sensor 42 and a timing device 39 such that electric scoring equipment and/or an opponent's saber can collect adequate information to determine not only which weapon sensed contact with a target area, but also which fencer should be awarded a touch based on the rules of the sport (i.e., under the current rules of saber fencing, if both fencers initiate an attack and neither fencer's blade contacts the other's blade, if one fencer initiated the action by advancing their saber forward first he or she is awarded a touch. If however both fencers advance their weapons relatively simultaneously, no touch is awarded. Transmitting the information that a touch is scored and information on timing and motion of the saber 12 can be very useful in aiding a director in awarding a touch or to render an automated touch award). Motion sensor 42 can be an accelerometer, a gyroscopic sensor, or any other motion sensor presently known to one of skill in the motion sensing art. Timing device 39 can be any timing device known to one of skill in the art. Using wireless device 43 eliminates the need for any wiring to be connected outside the saber 12 or beyond the fencer's personal system. This remarkably increases reliability by eliminating the need for wires and conductive target areas, the fencer's comfort and maneuverability, and reduce the cost of equipment needed in the prior art system. Further, fencers need not be connected to any electrical scoring equipment but can enjoy the same benefits from their sabers alone.
Power supply 41 supplies power for operation of processor 40, indicators 44, motion sensor 42, timing device 39, sensor blade 16 and wireless device 43. Saber 12 can also include a counter (not depicted) and a memory (not depicted) which can keep track of touches and any other relevant statistical information. The counter can have an automatic reset once it reaches a threshold, or it can resent when instructed from electrical scoring equipment or opponent's weapon. Indicator 44 may also include a display for displaying information from a counter, an electrical scoring system, or an opponent's weapon.
The saber configuration of
While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.