DE10055824C2 - System for automatically locating a projectile stuck in a target area of a target object - Google Patents

Description

The invention relates to a system for automatic registration of a in a target area of a projectile stuck in the target, with resonant circuits comprising coils Generation of alternating electromagnetic fields, the coils being the target fields of the target object limit, and with measuring elements for measuring a depending on the Interaction of the projectile with the alternating field variable physical size.

Such systems are currently used in particular on targets for darts, so-called dart boards. This eliminates the tedious counting and noting of the hits. Inzwi special competitions have arisen in which automated hit recording is essential, e.g. B. Speed darts, in which the arrows are to be thrown in the fastest possible sequence.

A dartboard is known from EP 09 77 004 A2, in which one of an alternating field source outgoing alternating electromagnetic field is directed at the dart board. in the The rear area of the dart board is one or more receiving elements for each field provided that detect the alternating electromagnetic field and a dependent Send the signal to an evaluation unit. Now a dart lands in a certain target field of the darts board, the metallic part of the dart interacts with the alternating electromagnetic field, resulting in a changed signal of the receiving element leads. The change is registered by the evaluation unit and in a hit display implemented. In this way it is possible to use the original metal tip to use darts and to record the results electronically. there the dart boards can be constructed from pressed sisal bristles.

In this prior art, it is particularly disadvantageous that the receiving elements are behind the sisal bristles and thus at a not inconsiderable distance from the target surface of the dart Boards are lying. An arrow that penetrates diagonally at the edge of a certain target field could also be used the arrowhead below the target surface are already in a neighboring field and thus become one lead to unreliable point evaluation.  

Dart boards made of plastic are also known, which can be scanned via an electronic hit system. The target is punched, and one hitting in such a hole Arrow mechanically releases an electrical signal on a sensor behind it out. The arrows must have an arrowhead made of plastic, which ver easily can bend or break off. Broken arrowheads have to laboriously get out of the darts board be removed. In addition, these arrows point towards the classic darts with steel tip a different weight and a different weight distribution.

There are also dart boards with optical hit detection, which also include classic dart boards made of sisal bristles and arrows with metal tips can be used. The arrows are detected and localized using a laser with an associated sensor. The determined position of the stuck arrow becomes a specific segment of the dart board assigned. This variant has a comparatively high price disadvantageous. In addition, hit detection is not very reliable, especially if the arrow - possibly at an angle - in the border areas of two target fields.

DE 298 20 311 U1 discloses a system of the type mentioned at the beginning for registering Hitting on a dart board where every single target field from a coil winding is surrounded. The two connection ends of each coil are with several analog switches connected. These in turn are connected to a central processor unit, so that a Target field can be localized. If a metallic dart hits a target area, so this causes a change in the magnetic field within the current-carrying coil and a signal is sent to the CPU that allows the hit to be registered. Therefore Each target field is provided with one coil, so there is a large number of coils is this system in terms of cost and the complex evaluation circuit disadvantageous.

It is an object of the present invention to provide a system of the type mentioned at the outset to provide a more cost-effective and less time-consuming hit registration Target objects of all kinds, d. H. in addition to darts boards, targets for other bullets, e.g. B. Arrows for archery.  

In a system of the type mentioned at the outset, the object is achieved in that at least some of the coils each delimit target field groups with more than one target field, whereby each at least one target field of one of the target field groups also belongs to another target field group.

Because of the considerably smaller number of coils, the material consumption becomes reduced for the coils themselves, on the other hand, there is significantly less effort for the subsequent one Evaluation circuit necessary, so that the arrangement according to the invention is essential leads to cheaper solution.

The coils can be placed on the target object or close to the surface in the target object be worked so that the coils enclose the projectile stuck in the target object. is especially the tip of the projectile or another part of the projectile is magnetically active, the inductances of the coils are changed by the projectile. By monitoring one a physical quantity dependent on the inductances of the coils can thus exist Storey can be registered. This principle can be manufactured very reliably and inexpensively become.

The system according to the invention can also be designed such that the measuring elements for detection solution of a resonance frequency change of the resonant circuits are provided. The Resonance frequency is a sensitive and therefore dependent on the inductance of the coil reliably measurable size. By means of a change in resonance frequency, it can thus be determined whether a projectile has hit the target area defined by the coil. there it is irrelevant whether the target area previously had a floor or was empty.

It can also be advantageous to design the system according to the invention in such a way that the measuring elements elements for measuring the reactance of the coils are provided.

Regardless of the size to be measured, the measuring times should be relatively short, if possible below a second, held and the corresponding resonant circuits continuously queried become.

Furthermore, the system according to the invention can be designed such that at least a part of it Number of resonant circuits have common resonant circuit elements and the coils of these  Oscillating circuits via a multiplex unit to the oscillation common to the oscillating circuits circular elements are connected. This is typically with multiple target targets given fields. Dart boards in particular have 82 actual target areas, one of which is a group is bounded by a coil. Different coils are electrical, e.g. B. by coating the winding wire, isolated from each other.

The coils delimit target field groups. A dart board can serve as a target field group for example the number of target fields forming a ring, such as the triple count, are considered to be the same as the other target fields forming a segment of the dart board Score. If a projectile hits a certain target field, the measuring elements would become one for the corresponding ring area and the other for the corresponding segment register a hit. Because the ring area and the segment area are only one target field have in common, the assignment would be clear.

Furthermore, it is also conceivable that the area outside the point-earning Target fields from a coil, so to speak as a zero target field or improper target field with is delimited. False throws could also be registered and counted.

Furthermore, it can be advantageous to design the system in such a way that the oscillating circuits common resonant circuit elements comprise an oscillator unit with a capacitance. Consequently can be a single oscillator unit and a single capacitance with multiple coils work together, i.e. be part of several resonant circuits. Alternatively, it goes without saying Lich also be provided to connect a capacitance to each coil in parallel and one Number of coils / capacitance units via the multiplex unit to a single oscillator connected, which would then be the only common component of several resonant circuits.

The connected coils are queried one after the other by means of the multiplex unit. It is possible to scan several coils at the same time, which saves time. there care must be taken that the coils queried at the same time unite on the target object have the greatest possible distance from each other. Otherwise there is a risk that due to an inductive coupling of adjacent coils the frequency of which is influenced, so that ultimately all coils of the same type queried simultaneously, i.e. H. z. B. same  Size that would vibrate on the same frequency. An evaluation separated by coils based on the resonance frequency measurement would then no longer be possible.

The system according to the invention can also be designed in such a way that one that is essentially si nus-shaped AC voltage in a square wave comparator converting the Taps the resonant circuit on the oscillator unit. In this way the vibration frequency of the associated resonant circuit can be fed to binary processing.

The system according to the invention can also be designed such that a counter unit for fixed position of the resonant circuit frequency taps the square wave voltage at the comparator unit and the signals of the counter unit are fed to a computer unit. In the computing unit can a display unit can be integrated.

Finally, the system according to the invention can be designed such that the coils are in one attachable to the target object and dividing the target object into the target fields body are housed. Such segmentation bodies are particularly useful in darts Boards common to prevent an arrow from landing exactly on a border of two target fields and a clear assignment is not possible. The segmentation bodies are ideal shaped so that the arrow is unlikely to jump off. Rather, the Arrow when touching the segmentation body to one of the adjacent target fields guided in such a way that the arrow gets stuck there. The are in the segmentation body Coils protected from being destroyed by projectiles. It also ensures that the coil is arranged above the surface of the target object and thus the stuck Bullets are surrounded by the coil.

The system according to the invention can be manufactured as a unit independently of a target and be driven out. It is easily possible to target, especially classic ones Retrofit dart boards without automatic hit registration.

A preferred embodiment of the system according to the invention is described below represented by figures.

It shows schematically  

Fig. 1 shows a cross section through a part of a dart board with segmentation body, bobbins and a plug dart,

Fig. 2 sections of a dart board in supervision and

Fig. 3 is a block diagram for resonance frequency measurement in resonant circuits of the system according to the invention.

Fig. 1 shows a dart 1 , which is in a target field 2 of a dart board 3 , which in Fig. 1 in cross section (essentially limited to the target field 2 ) and in Fig. 2 in supervision (be limited to three of the twenty Segments of the dart board 3 ) is shown. The target fields 2 are delimited by a segmentation body 4 , which is shown oversized in FIG. 1. Sections of the segmentation body separate neighboring target fields 2 or target fields 2 of outer circle 8 of dart board 3 from the outside. Several target fields 2 are combined in target field groups, each of which is surrounded by a coil 7 . The coils are guided through a cavity 6 given in the segmentation body 4 . In the case of a dart board, the number of target fields forming a ring, for example that of triple counting, can be regarded as a target field group, for example, as another target field forming the same number of points forming a segment of the dart board. If a projectile hits a certain target field, the measuring elements register a hit on the one hand for the corresponding ring area and on the other hand for the corresponding segment. The assignment of the hit to a target field is clear, since the ring area and the segment area have only one common field. In a section of the segmentation body 4 that separates two adjacent groups of target fields 2 from one another, two coils 7 a and 7 b or 7 a and 7 c must therefore run (see FIG. 1). In Fig. 1, the coils 7 a, 7 b and 7 c as the sections of the segmentation approximately 4 body are shown greatly enlarged. The coils 7 a, 7 b and 7 c constituent and guided in several turns electric wires 9 a, 9 b and 9 c with an insulate the lacquer provided so that the run in the same section of the segmentation body 4 the coils 7 a and 7 b or 7 a and 7 c are electrically insulated from one another. Through the hollow space 6 of the segmentation body 4 , in addition to the coils 7 a, 7 b and 7 c, feed lines (not shown) to other coils in the segmentation body 4 can also extend here. The supply lines can be performed in a manner not shown here through the dart board on the back or on the outermost portions of the segmentation body 4 to the side outside.

The inductance of the coils 7 a, 7 b and 7 c changes when a body with a component that has a permeability not equal to 1 is introduced into the coil cross section. The influence of a dart arrow with a metallic tip on the inductance of such a coil can thus be used to register an arrow 1 in a target field 2 .

Are as shown in Fig. 3 illustrates schematically in a block diagram of the coils, of which in Fig. 3 by way of example 7a, 7b and 7c, via supply lines 9 a, 9 b and 9 c with a Mul tiplexeinheit 10. Via the multiplex unit 10 , the individual coils 7 can be contacted one after the other with an oscillator unit 11 having a capacitance 12 . The oscillator unit 11 forms with each coil connected to the oscillator unit 11 via the multiplex unit 10 , e.g. B. 7a, each a resonant circuit. The respective resonant circuit is excited and the resonance frequency is determined after a settling time. For this purpose, the sinusoidal oscillation generated in the resonant circuit is fed to a comparator unit 13 , which generates a square-wave signal with TTL voltage from the sinusoidal signal. In an evaluation unit 14, a counter unit 15 equipped with a frequency counter logic determines the current frequency of the resonant circuit, which is temporarily stored in a display and computer unit 16 . In this way, all the coils 7 hanging on the multiplex unit 10 are interrogated. In the next subsequent run, the determined resonance frequencies are compared by the display and computer unit 16 with that of the previous run. If there is a change in resonance frequency that exceeds a predetermined limit value, a hit is registered for each target field group concerned. From the combination of the different target field groups hit, a single target field can then be localized and the hit for this can be displayed. In the display and computer unit 16 , the individual target fields are assigned 2 point scores, so that the display unit can not only display the fact of the meeting, but also the number of points achieved in the process.

The fields of a dart board can be recorded, for example, by coils when the each of the circle segments and on the other the rings of double and triple counting as Target field group considered and each surrounded by a coil.  

For example, three multiplex units 10 can be provided for a dart board 3 , to each of which eight coils are connected in order to cover the 82 actual target fields 2 of a dart board 3 . Other combinations are of course also possible. In FIG. 3, connections 17 are indicated on the display and computer unit 16 for further counter units 15 , comparator units 13 , oscillator units 11 and multiplex units 10 with the associated coils 7 .

Claims (8)

1. System for automatic registration of a projectile ( 1 ) stuck in one of several target fields ( 2 ) of a target object ( 3 ), with resonant circuits comprising coils ( 7 ) for generating alternating electromagnetic fields, the coils ( 7 ) being the target fields ( 2 ) of the Delimit the target object ( 3 ), and with measuring elements for measuring a physical variable that changes depending on the interaction of the projectile ( 1 ) with the alternating field, characterized in that at least some of the coils ( 7 ) each have target field groups with more than one target field ( 2 ) delimit, at least one target field ( 2 ) belonging to one of the target field groups also belonging to another of the target field groups. 2. System according to claim 1, characterized in that the measuring elements for Detection of a resonance frequency change of the resonant circuits are provided. 3. System according to claim 1, characterized in that the measuring elements for measuring the reactance of the coils ( 7 ) of the resonant circuits are provided. 4. System according to any one of the preceding claims, characterized in that at least some of the resonant circuits have common resonant circuit elements and the coils ( 7 ) of these resonant circuits are connected via a multiplex unit ( 10 ) to the resonant circuit elements common to the resonant circuits. 5. System according to claim 4, characterized in that the oscillating circuit elements common to the oscillating circuit elements comprise an oscillator unit ( 11 ) with a capacitance ( 12 ). 6. System according to claim 5 and 2, characterized in that one of the essential sinusoidal AC voltage converting into a square-wave voltage comparator unit ( 13 ) taps the resonant circuit on the oscillator unit ( 11 ). 7. System according to claim 6, characterized in that a counter unit ( 15 ) for determining the resonant circuit frequency taps the square wave voltage at the comparator unit ( 13 ) and the signals of the counter unit ( 15 ) are fed to a computer unit ( 16 ). 8. System according to one of the preceding claims, characterized in that the coils ( 7 ) are accommodated in a segmentation body ( 4 ) which can be attached to the target object and divides the target object into the target fields ( 2 ).