This application claims priority to Chinese patent application no. CN 201510490545.X, filed on Aug. 11,2015, and Chinese patent application no. CN 201520602963.9, filed on Aug. 11, 2015, the contents of which are incorporated in this disclosure in their entireties by reference.
The present disclosure relates generally to an electronic device for sports shooting.
In shooting training and events, electronic target systems that can be used include double-electrode short-circuit sampling systems, semiconductor electronic target systems, image processing based target systems, ultrasonic positioning electronic target systems, and laser electronic target systems, for example.
Laser electronic target systems are suitable for shooting events because they mainly consume electric power, have high detection precision for target hit due to digitized signals, and require little maintenance. When compared to other electronic targeting devices, laser electronic target systems can have the highest detection precision for target hits, use no disposable target supplies, and satisfy the requirement of detection precision for target hits and efficiency.
Disclosed herein is a laser electronic target system using non-overlapping and crossing rectangular laser screens, comprising a bullet trap and a first and second rectangular laser screens generated in front of the bullet trap, wherein each of the first and second rectangular laser screens is generated by a detachable laser transmitter and a laser receiver comprising a first sensor strip and a second sensor strip, wherein a first end of the first sensor strip is perpendicularly connected to a second end of the second sensor strip, wherein each sensor strip comprises 100 to 150 laser sensors, and wherein the laser transmitter and the first and second sensor strips are on a same plane.
In another aspect, a laser electronic targeting device is disclosed herein, comprising a casing, a controller, a first laser transmitter in communication with the controller and coupled to the casing, the first laser transmitter emitting a first laser defining a first plane, a second laser transmitter in communication with the controller and coupled to the casing in a position different from the first laser transmitter, the second laser transmitter emitting a second laser defining a second plane different from the first plane, wherein the second laser transmitter is displaced from the first laser transmitter such that the second plane defined by the second laser is parallel to the first plane defined by the first laser, a first laser receiver in communication with the controller and coupled to the casing, the first laser receiver being capable of receiving the first laser emitted by the first laser transmitter, and a second laser receiver in communication with the controller and coupled to the casing, the second laser receiver capable of receiving the second laser emitted by the second laser transmitter.
In another aspect, a laser electronic target system is disclosed herein, comprising a bullet trap and a plurality of laser screens generated in front of the bullet trap, wherein each of the plurality of laser screens is respectively in a plane mutually parallel to other laser screens, wherein each of the plurality of laser screens is generated by a laser transmitter and a laser receiver, wherein the laser transmitter and the laser receiver are located on the plane that the laser screen resides in, and wherein each laser transmitter of the plurality of laser screens emits laser in a direction different from other laser transmitters.
The disclosure is best understood from the following detailed description when read in conjunction with the accompanying drawings.
Compared with other target systems, double-electrode short-circuit sampling systems have a lower detection rate of target-hits for scoring, and do not meet the standards of shooting training and matches. Semiconductor electronic target system have simple designs, require little maintenance, and have high detection precision for target hits, but usage of such systems is limited due to high cost. Image processing based systems provide simple functions and fair scoring results, but have low detection precision for target hits and a slow reaction, which is not suitable for real-time scoring.
Ultrasonic positioning electronic target systems are widely used in shooting events. The principle of ultrasonic positioning electronic target systems is that, when a bullet passes through the disposable target supplies (e.g., a PVC rubber blanket), analog ultrasonic information of target-hit points can be generated and obtained by ultrasonic sensors (e.g., ultrasonic probes) to determine the value of the hit ring. They can adapt to the ambient environment, tolerate complex environmental conditions such as darkness or electromagnetic interferences, and have a certain detection precision for target hits. However, they have several limitations. For example, position errors or deviations can be introduced to the ultrasonic probes during their installation or maintenance. For another example, before each shooting event, the positions of the ultrasonic probes need calibration according to the environment and their own measurement uncertainties, and their positions cannot be changed during use; otherwise, the values of the determined hit ring will be affected. For another example, ultrasonic positioning electronic target systems usually include moving components (e.g., a motor or a rubber blanket rewinder) which are prone to mechanical malfunctions, causing deviation of the values of the determined hit rings. For another example, the disposable target supplies (the rubber blanket) of the ultrasonic target system must maintain a certain level of tension verticality and horizontality; otherwise, the value of the hit ring will also be affected. Moreover, ultrasonic positioning electronic target systems consume large quantities of disposable target supplies, which need to be replaced after each use. The high purchasing cost of disposable target supplies limits the use of ultrasonic positioning electronic target systems, especially for ranges and facilities with low budgets.
Compared to ultrasonic positioning electronic target systems, laser electronic target systems do not use disposable target supplies, minimize moving components within the system, can use precision machining (e.g., by numerical control machines) for its optical transmitter and receiver to reduce positioning errors during installation, and can achieve high detection precision by using a method to determine positions of target-hit points using a laser array and angles.
Laser electronic target systems can have various implementations. For example, some systems can be based on laser beam arrays, in which multiple laser transmitters and receivers are placed in an alternating corresponding order and digital signals generated from a bullet passing through the laser beam arrays can be used to determine the position of a target-hit point.
According to implementations of this disclosure, a laser electronic target system using non-overlapping and crossing rectangular laser screens is disclosed herein. The disclosed laser electronic target system can use detachable/replaceable laser transmitters/modules, which can reduce maintenance and repair costs when the service lives of the laser transmitters are reached or exceeded.
For example, the disclosed laser electronic target system can include a bullet trap and two rectangular laser screens generated in front of the bullet trap. Each of the rectangular laser screens can be generated by, for example, a detachable laser transmitter (e.g., a line laser transmitter) and two sensor strips (including a first and a second sensor strip) as a laser receiver. As shown in
As shown in
In some implementations, each sensor strip can include 115 light sensing points (e.g., light sensors) and there can be a total of 230 light sensing points for a laser receiver having two perpendicular sensor strips. In some implementations, the target system can include at least two laser screens, where the laser screens are non-overlapping and associated with a laser emission direction. In such a system, a position on a plane can be determined as set forth in the following description.
Regarding design, this disclosure sets forth a concept of crossing rectangular laser screens. Due to the game rules of 25 m and 50 m shooting matches, laser targets can be limited in size. The size of the laser electronic targets as disclosed herein can be made relatively small, with the benefits of reducing costs and leaving the center spacing between targets unaffected. For example, if using technology of arc-shape laser screens, which, for example, can be used in 10 m shooting matches, the casing sizes of 25 m or 50 m targets can be relatively large, thus raising the costs and affecting the center spacing between targets.
In some implementations, two non-overlapping laser screens can be used to detect position data for target hits of bullets, and the laser transmitters can be detachable or replaceable line laser transmitters or modules. In some implementations, the sensor strips can form a rectangular frame in a plane perpendicular to a center line (the dashed line shown in
In some implementations, the casing of the electronic target can have a volume approximate to the casing of an ultrasonic positioning electronic target. The shell of the casing can be made using laser cutting and splice welding, ensuring precise geometric properties such as perpendicularity and verticality.
When a bullet passes through a rectangular laser screen, a digital signal can be instantly generated at the two sensor strips (as a laser receiver), each sensor strip having 115 laser sensing points (e.g., laser sensors). The laser receiver of the rectangular laser screens can output signals of 0 and 1, in which the 0 and 1 can be used to represent whether an optical path is obstructed. The use of digital signals can reduce errors of numerical values compared to the use of analog signals.
For example, the laser receivers can be connected perpendicularly, and the time resolution of the laser receivers can be 10 ns. The “time resolution” herein refers to the minimum time interval that a sensor can discern between two different detected signals, such as between “0” and “1,” “on” and “off,” “voltage/current high” and “voltage/current low,” “light blocked” and “light unblocked,” or any other possible signals permitted by existing sensor technologies. For example, a 10 ns time resolution of a laser sensor means that, if any time interval of a laser beam changing from “unblocked” to “blocked,” or vice versa, is less than 10 ns, the laser sensor cannot detect such changes. In the above example, the digital signals instantly generated at the rectangular laser screen can be used to calculate the position of the target-hit points. For a bullet passing through the laser screen with a high speed (e.g., 300-450 m/s), since the rectangular laser screen has a high response time (e.g., time resolution), the system can be used as a laser target in 25 m and 50 m shooting events. In addition, based on the time duration of a beam being blocked at one or more sensors, the system can also determine entry of insects or other objects moving at a slower speed into the laser screens. For another example, if the bullet has a speed of 500 m/s, a length of 5 mm, then the time duration of the bullet obstructing the optical path is 10 μs. In the above example, the system can adopt a data acquisition rate of, for example, 10M Hz (equivalent to acquiring data in every 0.1 μs), which meets the requirement for detecting bullets passing the laser beams with high speeds. By using at least two laser screens, position coordinates of the target-hit points can be determined.
In one example, with a minimum diameter of a bullet such as 5.6 mm and a target size of 540 mm×540 mm, the spacing of the sensors can be set as, for example, 1.8 mm, by which the position of every passing bullet can be detected and differentiated. Other dimensions for the target size or sensor spacing can be used.
In some implementations, the laser transmitters can have a power of 100 mW and emit visible line lasers at wavelength 650 nm. By using a fixed wavelength of the laser, the system can avoid interferences from other electromagnetic or ultrasonic sources. In some implementations, the emitted visible line laser can project in a triangle shape with a vertex angle (e.g., 120°) at the line laser transmitter and irradiate evenly to the laser sensors of the corresponding perpendicular sensor strips. In the above example, each of the sensor strips can include 115 laser sensors with 1.8 mm spacing, in which a time resolution for each laser sensor can be less than 10 ns. When bullets are passing the laser screens, they will leave momentary shadows in the sensors and are only detectable with a sufficiently high time resolution (e.g., response speed). The two visible line lasers emitted by the two line laser transmitters can respectively irradiate to the two laser receivers having perpendicular sensor strips and position coordinates of the target-hit points can be determined based on the momentary shadows left by the bullet passing the laser screens with a high speed. In some examples, the receivers can be arranged in a 90 degree angle toward each other. The implementations as disclosed herein can effectively detect any bullet of any material with a 1-50 mm diameter, suitable for detection of target hits of guns for shooting events, such as air pistols, air rifles, center-fire guns, or any type of guns for military or law enforcement.
In some implementations, the position coordinates of the target-hit points can be calculated as follows.
As shown in
Let point C be the intersecting point of line BM with sensor strip 114, point D be the intersecting point of line AM with sensor strip 110, and AC=X2, BD=X1. Substituting tan
in Equation (1), then
Based on locations of the shadows (points C and D) left by the bullet passing through the laser screens at point M detected by the sensor strips, the location of point M with respect to target 120 can be determined from Equation (2).
According to implementations of this disclosure, by using the above method to determine positions of target-hit points using a laser array and angles, the measurement data can achieve high precision. For example, in some implementations, the spatial resolution of the coordinates of the positions of target-hit points can reach 0.1 mm and the precision of the values of the hit ring can reach 0.01 rings.
As shown in
For example, at operation 302, the detection process for a hit point of a bullet can be started by the laser sensors.
At operation 304, it is determined whether data scanning is completed. For example, the data can be scanned to determine whether the bullet detection process is completed. If yes, process 300 can proceed to operation 316 which transmits the data. If not, process 300 can proceed to operation 306.
At operation 306, hardware parameters of the system can be initialized.
At operation 308, it is determined whether interrupts are generated. If not, process 300 can proceed to operation 314 for malfunction processing. If yes, process 300 can proceed to operation 310.
At operation 310, data of the hit point can be received and processed, for example, by configurations shown in
At operation 312, based on the received and processed data, coordinates of the hit point can be computed.
At operation 314, data can be further processed and a malfunction can also be processed if any exists. When this operation ends, process 300 can go back to operation 304 to determine whether the detection process is completed.
As shown in
As shown in
According to this disclosure, the laser electronic target system disclosed herein uses a method to determine positions of target-hit points using a laser array and angles, which can increase efficiency, reduce cost, and avoid interferences from other electromagnetic or ultrasonic sources, thus being suitable for shooting training and matches.
Number | Date | Country | Kind |
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201510490545.X | Aug 2015 | CN | national |
201520602963.9 | Aug 2015 | CN | national |