A Transmission Method for Test Signals in a Free-Flight Test of a Ballistic Target

Abstract

An embodiment of the present invention relates to a method for transmitting test signals in a free flight test of a ballistic target, which is applied to a free flight test system of a ballistic target. The method includes: accelerating a test model to a preset speed by using a launcher so that the test model at the preset speed enters the target chamber from the launcher; sampling relevant parameters of the test model by using a test device at a preset sampling frequency to obtain first data of the test model at different times in the launcher and second data of the test model at different times in the target chamber; sending the first data obtained at each moment to a receiving device at least twice; wherein the moment of the first sending is the moment when the first data is obtained, and the moment of the second sending is delayed by a first time compared with the moment of the first sending; and sending the second data to the receiving device at least at the moment when the second data is obtained. This method can reduce the probability of transmission failure of test data in the launcher and improve the reliability of signal transmission.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of signal testing, and particularly to a method for transmitting test signals in a free flight test of a ballistic range target. Background Art

[0002] The hypersonic ballistic range test system is an important ground wind tunnel test system for researching hypersonic aerodynamics, aerophysics, and hypervelocity collision phenomena. This system consists of a launcher, a target chamber, a test device, and a receiving device. During the test, the test model is accelerated to hypersonic speed by the launcher and then conducts a free flight aerodynamic test in the target chamber. The test device collects the test data of various relevant parameters of the test model when it operates in the accelerator and the target chamber, and compiles the collected test data into test signals and sends them to the receiving device.

[0003] However, in the related art, when the test device and the receiving device perform signal transmission, some test signals of the test model in the launcher cannot be received by the receiving device, and the reliability of signal transmission is relatively low.

[0004] Therefore, there is an urgent need for a method for transmitting test signals in a free flight test of a ballistic range target to solve the above technical problems. Summary of the Invention

[0005] The embodiments of the present invention provide a method for transmitting test signals in a free flight test of a ballistic range target, which can reduce the probability of test data transmission failure in the launcher and improve the reliability of signal transmission.

[0006] The embodiments of the present invention provide a method for transmitting test signals in a free flight test of a ballistic range target. This method is applied to a free flight test system of a ballistic range target. The test system includes a launcher, a target chamber, a test device, and a receiving device; the outlet of the launcher is connected to the inlet of the target chamber, a test model is arranged in the launcher, the test device is installed on the test model, and the test device and the receiving device are communicatively connected; the method includes:

[0007] Using the launcher to accelerate the test model to a preset speed so that the test model at the preset speed enters the target chamber from the launcher;

[0008] Using the test device to sample the relevant parameters of the test model at a preset sampling frequency to obtain first data of the test model at different times in the launcher and second data of the test model at different times in the target chamber;

[0009] Sending the first data obtained at each moment to the receiving device at least twice; wherein the moment of the first transmission is the moment when the first data is obtained, and the moment of the second transmission is delayed by a first time compared to the moment of the first transmission;

[0010] At least at the moment of obtaining the second data, send the second data to the receiving device.

[0011] In a possible design, the second data obtained at each moment is sent to the receiving device at least twice; wherein, the moment of the first sending is the moment of obtaining the second data, and the moment of the second sending is delayed by a second time compared with the moment of the first sending.

[0012] In a possible design, the first time is equal to the second time.

[0013] In a possible design, the first time is determined according to the running time of the test model in the transmitter and in the target chamber.

[0014] In a possible design, the first time is greater than the running time of the test model in the transmitter and less than the running time of the test model in the target chamber.

[0015] In a possible design, the first time is 50 ms.

[0016] In a possible design, the step of sending the first data and the second data obtained at each moment to the receiving device at least twice respectively includes:

[0017] For each moment, perform:

[0018] Determine the data obtained at the target moment; if no data is obtained at the target moment, use a fixed code as the data obtained at the target moment; wherein, the time interval between the target moment and this moment is the first time, and the target moment is the moment before this moment;

[0019] Compile the data obtained at this moment and the data obtained at the target moment into a test signal in a preset format;

[0020] At this moment, send the test signal in the preset format to the receiving device.

[0021] In a possible design, the step of compiling the data obtained at this moment and the data obtained at the target moment into a test signal in a preset format includes:

[0022] Determine the transmission order of the relevant parameters of the test model;

[0023] According to the transmission order, sample the data corresponding to each relevant parameter at this moment and at the target moment in turn to compile into a test signal in a preset format.

[0024] In a possible design, the test signal in the preset format further includes a count code group, a check code group, and a synchronization code group.

[0025] In a possible design, the number of bytes occupied by the test data of each relevant parameter of the test model at different times is the same.

[0026] The embodiment of the present invention provides a method for transmitting a test signal in a free flight test of a ballistic target, which is applied to a free flight test system of a ballistic target. The method first uses a launcher to accelerate a test model to a super high speed, and then makes the test model perform a super high speed free flight aerodynamic test in a target chamber. During the test, a test device is used to obtain first data and second data of the test model at different times in the launcher and the target chamber respectively. Since when the test model is launched in the launcher, instantaneous physical phenomena such as high temperature, high pressure, firelight, and plasma will be generated, which will interfere with wireless signals and affect the transmission of test signals. Therefore, in this method, the first data obtained at each moment is sent to the receiving device at least twice. The first time is a real-time transmission, that is, it is sent at the moment when the first data is obtained. The second time is a delayed transmission, that is, it is sent after a first time delay after the first data is obtained. In this way, when the first data sent for the first time cannot be received by the receiving device due to signal interference, the first data sent for the second time can be used, thereby reducing the probability of failure in transmitting test data in the launcher and further improving the reliability of signal transmission. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 It is a flowchart of a method for transmitting a test signal in a free flight test of a ballistic target provided by an embodiment of the present invention;

[0029] Figure 2 It is a schematic diagram of the frame structure of a test signal at any moment provided by an embodiment of the present invention. Detailed Embodiments

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] As described above, in the existing method for transmitting test signals, some test signals in the transmitter cannot be received by the receiving device, resulting in low reliability of signal transmission.

[0032] To address this problem, the inventor found that when the test model is accelerated and launched in the transmitter, instantaneous physical phenomena such as high temperature, high pressure, firelight, and plasma will be generated, and these physical phenomena will interfere with wireless signals. Therefore, when the test device and the receiving device perform signal transmission, some signal transmissions will fail, resulting in the receiving device being unable to receive these signals and causing data loss.

[0033] Based on this, the inventor proposed that the test data in the transmitter can be transmitted to the receiving device twice, that is, it is transmitted once when the test data is obtained, and then the test data is transmitted again after a preset time delay, so as to reduce the probability of test data transmission failure.

[0034] The specific implementation of the above concept is described below.

[0035] Please refer to Figure 1 , an embodiment of the present invention provides a method for transmitting test signals in a free-flight test of a ballistic target, which is applied to a free-flight test system of a ballistic target. The test system includes a transmitter, a target chamber, a test device, and a receiving device; the outlet of the transmitter is connected to the inlet of the target chamber, a test model is arranged in the transmitter, the test device is installed on the test model, and the test device and the receiving device are communicatively connected;

[0036] The method includes:

[0037] Step 100, using the transmitter to accelerate the test model to a preset speed so that the test model at the preset speed enters the target chamber from the transmitter;

[0038] Step 102, using the test device to sample the relevant parameters of the test model at a preset sampling frequency to obtain first data of the test model at different times in the transmitter and second data of the test model at different times in the target chamber;

[0039] Step 104: Transmit the first data obtained at each moment to the receiving device at least twice; wherein, the moment of the first transmission is the moment when the first data is obtained, and the moment of the second transmission is delayed by a first time compared to the moment of the first transmission.

[0040] Step 106: Transmit the second data to the receiving device at least at the moment when the second data is obtained.

[0041] In the embodiments of the present invention, first, the test model is accelerated to a super-high speed by the emitter, and then the test model performs a super-high speed free flight aerodynamic test in the target chamber. During the test, the first data and the second data of the test model at different moments in the emitter and in the target chamber are respectively obtained by the test device. Since physical phenomena such as instantaneous high temperature, high pressure, fire light, and plasma will be generated when the test model is launched in the emitter, which will interfere with the wireless signal and affect the transmission of the test signal. Therefore, in this method, the first data obtained at each moment is transmitted to the receiving device at least twice. The first time is real-time transmission, that is, it is transmitted at the moment when the first data is obtained, and the second time is delayed transmission, that is, it is transmitted after a first time delay after the first data is obtained. In this way, when the first data transmitted for the first time cannot be received by the receiving device due to signal interference, the first data transmitted for the second time can be used, thereby reducing the probability of transmission failure of the test data in the emitter and further improving the reliability of signal transmission.

[0042] The following describes Figure 1 The execution manners of the steps shown.

[0043] First, for step 100, the test model is accelerated to a preset speed by the emitter so that the accelerated test model enters the target chamber from the emitter.

[0044] In this step, the emitter is equivalent to a gun barrel, and the test model placed inside it can be accelerated to a preset speed according to the test requirements. Usually, the preset speed is a super-high speed. For example, the emitter can accelerate a conical aerodynamic test model with a bottom diameter of 25 mm to 7.3 km / s. After the test model enters the target chamber at this speed, under the action of inertial force and aerodynamic force, it performs a super-high speed free flight aerodynamic test in the target chamber, thereby simulating the operating state of the test model in this environment. Of course, the user can determine the shape and size of the test model according to actual needs, such as an aircraft, etc., and the present application does not make specific limitations.

[0045] Then, for step 102, the test device samples the relevant parameters of the test model at a preset sampling frequency to obtain the first data of the test model at different moments in the emitter and the second data of the test model at different moments in the target chamber.

[0046] Among them, the relevant parameters of the test model include the temperature, pressure, acceleration, overload, and position of the model, etc. The user can sample one or more parameters according to needs, and the operating state of the test model during the entire pneumatic test process (including acceleration in the launcher and free flight in the target chamber) can be obtained based on the sampled data. It can be understood that the higher the sampling frequency, the finer the test results obtained, but more computer resources are required. On the contrary, the lower the sampling frequency, the coarser the test results and the less computer resources are occupied. The user can determine the sampling frequency according to the actual situation. In some embodiments, the preset sampling frequency is in the millisecond level, for example, several milliseconds to dozens of milliseconds. The present application does not make specific limitations on the specific values.

[0047] Finally, for steps 104 and 106, the first data obtained at each moment is sent to the receiving device at least twice; wherein, the moment of the first transmission is the moment when the first data is obtained, and the moment of the second transmission is delayed by a first time compared to the moment of the first transmission.

[0048] At least at the moment when the second data is obtained, the second data is sent to the receiving device.

[0049] As mentioned above, the test model conducts a free flight pneumatic test in the target chamber at ultra-high speed. When the test ends (i.e., the test model flies to the end of the target chamber), it still has a high speed. At this time, it is necessary to intercept the test model flying at high speed. Due to the impact caused by the interception, the test model and the test device installed on the model will be damaged, and then the data stored on the test device cannot be exported. Therefore, during the flight test of the model, it is necessary to send while testing, that is, when the test device obtains the test data at a certain moment, the data should be compiled into a test signal in real time and the test signal should be sent to the receiving device to prevent the data from not being exported after the model crashes.

[0050] In addition, when the test model accelerates in the launcher, instantaneous physical phenomena such as high temperature, high pressure, firelight, and plasma will be generated. These physical phenomena will interfere with the wireless signal, resulting in the failure of some test signal transmissions. By sending the first data in the launcher twice with a time delay between the two times, the probability of signal transmission failure can be effectively reduced, and the operating state of the test model in the launcher can be accurately obtained. At least at the moment when the second data is obtained, the second data is sent to the receiving device, and the test data of the test model during free flight in the target chamber can be obtained, so as to obtain the operating state of the test model in the target chamber.

[0051] In addition, although the operating environment inside the target chamber is relatively stable and the situation of signal transmission failure is rare, with the improvement of users' requirements for the accuracy of test results, in some embodiments, the second data obtained at each moment can also be sent to the receiving device at least twice; wherein, the time of the first transmission is the moment when the second data is obtained, and the time of the second transmission is delayed by a second time compared to the time of the first transmission. In this way, the probability of data loss caused by the failure of the data (real-time data) transmitted for the first time inside the target chamber due to changes in the internal or external environment can be avoided, and the reliability of signal transmission inside the target chamber can be further improved, so as to accurately obtain the operating state of the test model throughout the test process.

[0052] It should be noted that if the test model crashes when flying to the exit of the target chamber, the second data collected for the last time or multiple times cannot be transmitted for the second time, then only one signal transmission is required. That is to say, in some embodiments, the second data obtained at some moments can be sent to the receiving device at least twice; wherein, the time of the first transmission is the moment when the second data is obtained, and the time of the second transmission is delayed by a second time compared to the time of the first transmission. In this embodiment, since the wireless signal is basically not interfered by the above physical phenomena when the test model runs near the exit of the target chamber, some of the second data is only transmitted once, which does not affect the overall reliability of signal transmission.

[0053] In addition, transmitting the data at each moment twice is a preferred method. In other embodiments, the user can also transmit the data three times or more times, and the present application does not make specific limitations.

[0054] In some embodiments, the first time is equal to the second time, that is, the delay transmission times of the first data and the second data are the same. In this way, the conditioning and editing of the data can be made more convenient, and at the same time, it is beneficial for the receiving device to decode and analyze the test signal.

[0055] In some embodiments, the first time is determined according to the running time of the test model inside the launcher and inside the target chamber.

[0056] In some embodiments, the method for determining the running time of the test model inside the launcher and inside the target chamber is as follows:

[0057] According to the length of the launcher and the running speed of the test model inside the launcher, determine the first running time of the test model inside the launcher;

[0058] According to the length of the target chamber and the running speed of the test model inside the target chamber, determine the second running time of the test model inside the target chamber;

[0059] Determine the first time according to the first running time and the second running time.

[0060] In this embodiment, the lengths of the emitter and the target chamber are known quantities. The flight speed of the test model in the emitter and the target chamber can be the average speed, and the speed value can be an estimated value or determined through simulation calculations.

[0061] In some embodiments, to achieve the best signal transmission effect, the first time is greater than the running time of the test model in the emitter and less than the running time of the test model in the target chamber, that is, the first time is greater than the first running time and less than the second running time.

[0062] The first time being greater than the first running time, that is, the first time being greater than the running time of the test model in the emitter, can ensure that when the second signal transmission is carried out, the test device has completely escaped the interference of physical phenomena such as high temperature, high pressure, fire light, and plasma. In this way, the probability that the data sent the second time is received by the receiving device can be further increased.

[0063] The first time being less than the second running time, that is, the first time being less than the running time of the test model in the target chamber, can ensure that when the first data is transmitted the second time, the test model has not reached the exit of the target chamber, and the first data will not fail to be sent due to the test model and the test device being damaged.

[0064] Of course, the first time being greater than the first running time and less than the second running time is only a preferred method. In other embodiments, the first time can also be equal to the first running time or equal to the second running time, and the present application does not make specific limitations.

[0065] In some embodiments, the first time is 50 ms, and this time is applicable to most existing ballistic target free-flight test systems.

[0066] In some embodiments, the first data obtained at each moment and the second data obtained at each moment are each sent to the receiving device at least twice, including:

[0067] For each moment, the following operations are performed:

[0068] Determine the data obtained at the target moment; if no data is obtained at the target moment, use the fixed code as the data obtained at the target moment; wherein, the time interval between the target moment and this moment is the first time, and the target moment is the moment before this moment;

[0069] Compile the data obtained at this moment and the data obtained at the target moment into a test signal in a preset format;

[0070] At this moment, send the test signal in the preset format to the receiving device.

[0071] In this embodiment, the test device includes an encoding and modulation unit and a transmitting antenna, and the receiving device includes a receiving antenna. The encoding and modulation unit is configured to encode the collected test data into a test signal in a preset format, and the transmitting antenna is configured to transmit the test signal to the receiving antenna. In order to save computer resources as much as possible and reduce the data rate, after the data obtained at each moment is sent in real time for the first time, it is not sent separately during the second sending. Instead, the data is combined with the data obtained at later moments and sent together. For example, this moment is T4, the target moment is T1, the moment T4 is delayed by a first time compared to the moment T1, the data obtained at the moment T4 is X4, and the data obtained at the moment T1 is X1. Then, the first sending time of X1 is the moment T1, and the second sending time is the moment T4, and during the second sending, it is sent together with X4 combined. And so on, to achieve sending the data obtained at each moment to the receiving device twice. Of course, the user can also, after the data obtained at each moment is sent in real time for the first time, delay for the first time and then send the data separately for the second time. The present application is not limited thereto.

[0072] It should be noted that if no data is obtained at the target moment, a fixed code is used as the data obtained at the target moment. For example, if the moment T1 is the moment of the first sampling, then no sampling is performed before the moment T1, and no data is generated either. Therefore, in order to maintain the consistency of the test signal format, a fixed code needs to be used instead, that is, the data obtained at the moment T1 is combined with the fixed code and then sent. The fixed code can be 1001, 1100, 1010, etc. The present application does not make specific limitations on the content of the fixed code.

[0073] In some embodiments, encoding the data obtained at this moment and the data obtained at the target moment into a test signal in a preset format includes:

[0074] Determine the transmission order of the relevant parameters of the test model;

[0075] According to this transmission order, sample the data corresponding to each relevant parameter at this moment and the target moment in sequence to encode into a test signal in a preset format.

[0076] In this embodiment, the transmission order of the relevant parameters of the test model can be set according to user requirements. For example, the transmission order of the relevant parameters is temperature, pressure, and acceleration. At this moment, it is time T4, and the target time is time T1. Then, when sampling the test data, the sampling can be carried out in the order of the temperature A4 at time T4, the temperature A1 at time T1, the pressure P4 at time T4, the pressure P1 at time T1, the acceleration G4 at time T4, and the acceleration G1 at time T1. Then, the obtained data is compiled into a test signal in the above order. The test signal at each moment is used as an independent frame structure and sent to the receiving device frame by frame. After receiving the test signal, the receiving device decodes the test signal frame by frame to obtain the test data.

[0077] In some embodiments, in order to accurately identify each frame, the test signal in a preset format further includes a count code group, a check code group, and a synchronization code group. Among them, the count code group is used to detect whether a frame is missed, the check code group is used to detect whether the transmitted data is correct, and the synchronization code group is used to identify the frame head and frame tail of each frame. The count code group, the check code group, the synchronization code group, and the above test data together form the frame structure at a certain moment. The schematic diagram of the complete frame structure is as Figure 2 shown. It can be seen from the figure that each frame contains N groups of parameters, a count code group, a check code group, and a synchronization code group. Each group of parameters is respectively composed of the test data at time T and the test data at time T'. Among them, the time interval between time T and time T' is the first time, and time T is the time after time T'. It should be noted that Figure 2 the output order of the groups of parameters in

[0078] is only an example. In other embodiments, the output order of the parameters can be adjusted according to actual needs.

[0079] In some embodiments, the test device further includes an upconverter and a power amplifier. After the data is compiled into a test signal in a preset format, it further includes:

[0080] using the upconverter to increase the frequency of the test signal, and using the power amplifier to increase the power of the test signal, so as to increase the signal strength of the test signal. By increasing the strength of the test signal, the reliability of the test signal during transmission can be further improved.

[0081] It should be noted that by adjusting the basic parameters such as the frame structure, modulation method, and data format of the test data, this method can also be used for signal transmission in test systems such as barrel guns and electromagnetic guns.

[0082] It should be noted that, in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising said element.

[0083] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for transmitting test signals in a free-flight test of a ballistic target, characterized in that, Applied to the free-flight test system of a ballistic range, the test system includes a launcher, a target chamber, a test device, and a receiving device; the outlet of the launcher is connected to the inlet of the target chamber, a test model is arranged in the launcher, the test device is installed on the test model, and the test device and the receiving device are communicatively connected; the method includes: Accelerating the test model to a preset speed by using the launcher, so that the test model at the preset speed enters the target chamber from the launcher; Sampling relevant parameters of the test model at a preset sampling frequency by using the test device to obtain first data of the test model at different times in the launcher and second data of the test model at different times in the target chamber; Sending the first data obtained at each moment to the receiving device at least twice; wherein, the moment of the first sending is the moment when the first data is obtained, and the moment of the second sending is delayed by a first time compared with the moment of the first sending; Sending the second data obtained at each moment to the receiving device at least twice; wherein, the moment of the first sending is the moment when the second data is obtained, and the moment of the second sending is delayed by a second time compared with the moment of the first sending; The first time is equal to the second time; The first time is greater than the running time of the test model in the launcher and less than the running time of the test model in the target chamber.

2. The method according to claim 1, wherein The first time is determined according to the running time of the test model in the launcher and in the target chamber.

3. The method according to claim 1, characterized in that, The first time is 50 ms.

4. The method according to claim 1, wherein The sending the first data obtained at each moment and the second data obtained at each moment to the receiving device at least twice respectively includes: For each moment, execute: Determine the data obtained at the target moment; if no data is obtained at the target moment, use a fixed code as the data obtained at the target moment; wherein, the time interval between the target moment and this moment is the first time, and the target moment is the moment before this moment; Compile the data obtained at this moment and the data obtained at the target moment into a test signal in a preset format; At this moment, send the test signal in the preset format to the receiving device.

5. The method according to claim 4, characterized in that, The compiling the data obtained at this moment and the data obtained at the target moment into a test signal in a preset format includes: Determine the transmission order of each relevant parameter of the test model; According to the transmission order, sample the data corresponding to each relevant parameter at this moment and at the target moment in turn to compile into a test signal in a preset format.

6. The method according to claim 4, wherein The test signal in the preset format further includes a count code group, a check code group, and a synchronization code group.

7. The method according to claim 1, wherein The number of bytes occupied by the test data of each relevant parameter of the test model at different times is the same.

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