A large-caliber ballistic target driven by electromagnetic catapult

Abstract

The present invention provides a large-caliber ballistic target driven by an electromagnetic catapult, comprising an electromagnetic catapult device, an armature, a model, an expansion tank, a test chamber, a vacuum system, and a measurement and control system. The electromagnetic catapult device comprises a launch tube, a multi-stage drive coil wound around the launch tube, and an excitation power supply for supplying power to the multi-stage drive coil; the launch tube, expansion tank, and test chamber are connected in sequence; the launch tube is equipped with an armature and a model, with the armature located behind the model; the launch tube, expansion tank, and test chamber are filled with test gas; the excitation power supply discharges step by step through the multi-stage drive coil to generate a pulsed magnetic field, and the armature moves under the action of electromagnetic force and propels the model to be launched at high speed through the expansion tank into the test chamber. The present invention adopts a one-stage electromagnetic catapult drive method, which is safer and cleaner than gunpowder, hydrogen-oxygen detonation, and other methods; the model size is larger than that of a two-stage or three-stage light gas gun; and a multi-stage coil energization and single-stage independent adjustment method can be used to optimize interior ballistic characteristics and achieve "soft launch."

Description

Technical Field

[0001] The present application relates to the technical field of ultra-high-speed flight ground simulation tests, and in particular to a large-caliber ballistic target driven by an electromagnetic catapult. Background Art

[0002] A ballistic target is a ground-based aerodynamic test device that enables aerodynamic test models to fly freely in static air. It simulates real-world flight flow conditions and is used for testing aerodynamic forces / heat, aerodynamic physics, and hypervelocity collisions. The ballistic target primarily consists of a model launcher, a test system, and a measurement and control system. Due to the scale effect of model flight ground simulation tests, all other conditions being equal, the closer the model size is to the prototype aircraft size, the closer the ground simulation data will be to reality. Under the same launch velocity conditions, larger launcher calibers and larger model sizes result in better simulation results.

[0003] The first-stage power source of a ballistic target launcher is usually gunpowder, compressed gas, or hydrogen-oxygen detonation. It mainly has a one-stage gun, a two-stage light gas gun, and a three-stage light gas gun. Among them, the two-stage light gas gun is the most common. The first-stage gun can load the projectile at a maximum speed of about 2km / s, the second-stage light gas gun can accelerate the projectile to a maximum of 8km / s, and the third-stage light gas gun can accelerate the projectile to a maximum of about 11km / s. However, as the number of stages increases, the caliber of the launch tube decreases. Currently, the caliber of the launch tube of the second-stage light gas gun at home and abroad is usually less than 50mm, and the caliber of the launch tube of the third-stage light gas gun is usually less than 20mm, which cannot meet the requirements of large-scale model flight ground tests under ultra-high speed (8km / s and above). At the same time, the gas gun system generally has the inherent problem of a rapid decrease in base pressure after the projectile is launched, which cannot guarantee excellent interior ballistic performance. Summary of the Invention

[0004] This application aims to solve the problems of small caliber of existing ballistic targets, small size of launch models and unsatisfactory interior ballistic performance, explore the potential of the driving method of the electromagnetic catapult device, and provide an electromagnetic catapult-driven first-stage gun as a large-caliber ballistic target for the launch device, so as to ensure that the size of the test model is increased under hypervelocity launch conditions, while improving the interior ballistic performance, and providing a safer, more efficient, cleaner, more controllable and more stable large-caliber test platform for tests such as aerodynamics / thermal, aerodynamic physics and hypervelocity collision.

[0005] In a first aspect, a large-caliber ballistic target driven by an electromagnetic catapult is provided for performing flight measurement of a model, wherein the large-caliber ballistic target comprises an electromagnetic catapult device, an armature, an expansion tank, a test chamber, and a measurement and control system; wherein,

[0006] The electromagnetic catapult device includes a launch tube, a multi-stage drive coil wound on the launch tube, an excitation power supply for supplying power to the multi-stage drive coil, and a charger for charging the excitation power supply;

[0007] The launch tube, the expansion tank and the test chamber are connected in sequence, the launch tube contains the armature and the model, the model is mounted on the armature, and the inner diameter of the launch tube is not less than 50 mm;

[0008] Each stage of the driving coil is connected to an independent excitation power supply, and the excitation power supply is triggered step by step to discharge the multi-stage driving coils step by step. The armature moves under the action of the electromagnetic force generated by the multi-stage driving coils and pushes the model, and the model flies out of the launch tube, passes through the expansion tank, and enters the test chamber.

[0009] The measurement and control system is used to determine the triggering moment of each stage of the excitation power supply according to the moving speed and position of the armature.

[0010] In conjunction with the first aspect, in certain implementations of the first aspect, the multi-stage drive coil satisfies at least one of the following:

[0011] The number of stages of the multi-stage driving coil is n, where n≥3;

[0012] The structural parameters and electromagnetic parameters of the driving coils and excitation power supplies at each level are the same;

[0013] The ratio of the length of each driving coil to the inner diameter of the transmitting tube is 0.4 to 1.7;

[0014] The ratio of the distance between the facing end faces of the adjacent driving coils to the inner diameter of the transmitting tube is 0.1 to 0.3;

[0015] The conductor of the driving coil is made of copper, and the conductor of the driving coil is covered with insulating material.

[0016] The entire exterior of the multi-stage driving coil is covered by a metal layer.

[0017] In combination with the first aspect, in certain implementations of the first aspect, the excitation power supply includes an energy storage pulse capacitor group, a main switch, and a freewheeling switch; the energy storage pulse capacitor group is connected in series with the main switch and in parallel with the freewheeling switch at both ends of the drive coil, and the two ends of the energy storage pulse capacitor group are also connected to the two ends of the charger through a charging switch, and the conduction and disconnection of the main switch and the charging switch are controlled by the measurement and control system.

[0018] In conjunction with the first aspect, in certain implementations of the first aspect, the excitation power supply satisfies at least one of the following:

[0019] The energy storage pulse capacitor group is composed of a combination of metallized film self-healing pulse capacitors, and the energy volume ratio of the metallized film self-healing pulse capacitor is greater than or equal to 0.5MJ / m 3, working life is greater than or equal to 1000 times;

[0020] The main switch is a spark gap switch or a high-voltage switch composed of a semiconductor thyristor;

[0021] The freewheeling switch is composed of a combination of semiconductor high-voltage diodes.

[0022] In conjunction with the first aspect, in certain implementations of the first aspect, the measurement and control system includes a central controller, a pulse trigger circuit, and a laser Doppler armature speed measurement device;

[0023] The laser Doppler armature speed measuring device includes an armature speed measuring device main body and an armature speed measuring device probe. The armature speed measuring device probe is installed at the pipe opening sealing portion at one end of the transmitting tube. The armature speed measuring device main body and the armature speed measuring device probe are connected via an optical fiber.

[0024] The armature speed measuring device main body device transmits a laser signal to the armature through the armature speed measuring device probe and receives the laser signal reflected from the armature, and converts the laser signal into an electrical signal and transmits it to the central controller;

[0025] The central controller processes the electrical signal to obtain the armature position and instantaneous speed at each moment, and obtains the estimated triggering moment of the excitation power supply to be triggered;

[0026] At the expected triggering moment, the central controller sends a trigger control signal to the pulse triggering circuit, and the pulse triggering circuit outputs a power pulse to trigger the corresponding stage excitation power supply to be turned on.

[0027] In conjunction with the first aspect, in certain implementations of the first aspect, the central controller is configured to execute a timing trigger control method, and the timing trigger control method includes:

[0028] Step 1: i = 1, at time t i＝1 =0 triggers the first-stage excitation power supply to be turned on, and at the same time controls the laser Doppler armature speed measuring device to emit laser along the direction of movement of the armature;

[0029] Step 2: i = 2, at time t i＝2 Triggering the conduction of the second stage excitation power supply, the time t2 satisfies: t m <t2<2t m , where t m is the time interval when the discharge current of the driving coil rises from zero to the maximum value; at the same time, the laser Doppler armature speed measuring device is controlled to perform measurement to obtain the position and speed of the armature at time t2;

[0030] Step 3: Loop through the following steps 3-1 and 3-2 until the moment t at which the n-th stage excitation power supply is turned on is obtained.n :

[0031] Step 3-1: At time t i+1 Triggering the conduction of the i+1th level excitation power supply, the time t i+1 satisfy:

[0032] v i is time t i Armature speed, a is the average armature motion

[0033] acceleration, h is the center distance between two adjacent driving coils;

[0034] Step 3-2: Let i=i+1.

[0035] In conjunction with the first aspect, in certain implementations of the first aspect, t m according to OK, L d is the sum of all self-inductances of the first-stage discharge circuit, and C is the capacitance of the energy storage capacitor group.

[0036] In combination with the first aspect, in certain implementations of the first aspect, before starting, the rear end surface of the armature is aligned with the center line of the first-stage drive coil.

[0037] In conjunction with the first aspect, in certain implementations of the first aspect, the transmitting tube satisfies at least one of the following:

[0038] The transmitting tube is made of insulating material;

[0039] The maximum operating temperature of the launch tube is 260 degrees Celsius;

[0040] One of the launch tube openings is sealed by a plug, and the other opening is connected to the expansion tank via a flange;

[0041] When the launch tubes need to be connected to each other in sections using pipes of the same specification, each section of the launch tubes is connected using a flange structure, a Hough nut structure or a Hough clamp structure.

[0042] In conjunction with the first aspect, in certain implementations of the first aspect, the large-caliber ballistic target satisfies at least one of the following:

[0043] The armature structure is an integral solid cylinder or a hollow cylinder, and the armature material is aluminum or aluminum alloy;

[0044] The charger is an IGBT series resonant constant current charging power supply;

[0045] The test gas filled in the launch tube, the expansion tank and the test chamber is air, and the air pressure is 10Pa~0.2MPa;

[0046] The model is a full-caliber model without a sabot or a combined model with a sabot. When the model is a full-caliber model without a sabot, the model passes through an expansion box and enters the test chamber after launch. When the model is a combined model with a sabot, the combined model consists of a model body and a sabot. After the model is launched, the sabot and the model body are separated in the expansion box, and the model body enters the test chamber.

[0047] The expansion tank and the test chamber are connected to a vacuum system and are provided with a plurality of optical windows on the top and the side;

[0048] The expansion tank and the test chamber are equipped with a plurality of measuring devices, including a model velocity measurement system, a camera system for measuring the model position and posture, a shadow / schlieren instrument for displaying the flow field, and a light radiation measurement system for measuring light radiation characteristics;

[0049] The ballistic target includes several supporting mechanisms and a track system. The supporting mechanisms are respectively located under the launch tube, the expansion tank and the test chamber. The supporting mechanisms are installed on the track system and can move along the track.

[0050] In conjunction with the first aspect, in certain implementations of the first aspect, the method is applied to the large-caliber ballistic target as described in any one of the implementations of the first aspect, and the method includes:

[0051] Step 1: i = 1, at time t i＝1 =0 triggers the first-stage excitation power supply to be turned on, and at the same time controls the laser Doppler armature speed measuring device to emit laser along the direction of movement of the armature;

[0052] Step 2: i = 2, at time t i＝2 Triggering the conduction of the second stage excitation power supply, the time t2 satisfies: t m <t2<2t m , where t m is the time interval when the discharge current of the driving coil rises from zero to the maximum value; at the same time, the laser Doppler armature speed measuring device is controlled to perform measurement to obtain the position and speed of the armature at time t2;

[0053] Step 3: Loop through the following steps 3-1 and 3-2 until the moment t at which the n-th stage excitation power supply is turned on is obtained. n :

[0054] Step 3-1: At time t i+1 Triggering the conduction of the i+1th level excitation power supply, the time t i+1 satisfy:

[0055] v i is time t iArmature speed, a is the average speed of armature motion

[0056] speed, h is the center distance between two adjacent driving coils;

[0057] Step 3-2: Let i=i+1.

[0058] The beneficial effects of the present invention are:

[0059] (1) The launch device of the present invention adopts a first-stage gun structure directly driven by a multi-stage coil electromagnetic catapult device, and an insulating launch tube is set between the drive coil (primary) and the armature (secondary). Because the coupling efficiency and electromagnetic energy conversion efficiency will drop sharply when the caliber is below 50mm, the larger the caliber, the higher the electromagnetic energy conversion efficiency. The present invention sets the launch tube caliber to be at least greater than or equal to 50mm. If the caliber is 100mm or even above 200mm, the efficiency will be higher. Compared with the electromagnetic-driven second-stage gun launch tube, the caliber is increased several times. The large-caliber launch tube can ensure the electromagnetic coupling efficiency and electromagnetic energy conversion efficiency, which is particularly suitable for large-scale and large-mass model ballistic target test applications. By utilizing the multi-stage energizing characteristics of the electromagnetic drive device, the high energy supply problem required by large-caliber equipment can be solved by increasing the excitation power supply and the number of drive coils.

[0060] (2) The present invention adopts a multi-stage coil electromagnetic catapult device as the core launching device. Each stage of the driving coil is equipped with an independent excitation power supply, which has the characteristics of axial distribution, multi-stage empowerment, and single-stage independent control. Not only can the overall driving energy be increased by increasing the number of stages, but also the energy storage and empowerment schemes can be optimized by regulating the circuit structure parameters and electromagnetic parameters of each stage. While ensuring a high energy conversion efficiency, the speed and acceleration changes of the model movement process are relatively stable and controllable, thereby improving the overall interior ballistic characteristics and realizing "soft launch".

[0061] (3) The electromagnetic force generated by the discharge induction of the multi-stage drive coil used in the present invention is a safe, clean and efficient power source, which can effectively replace gunpowder or hydrogen-oxygen detonation drive, causes less damage to the device, has higher structural sealing and safety, and does not generate toxic gases during the test, and does not pollute the environment.

[0062] (4) With the breakthrough of high energy density energy storage technology, high voltage switch technology and high strength new insulation material technology bottlenecks, the future multi-stage coil electromagnetic catapult device can be modularized, miniaturized, lightweight and intelligent, and electromagnetic thrust as an independent power source for ballistic targets will have more and more advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 is a schematic diagram of the structure of a large-caliber ballistic target driven by electromagnetic catapult.

[0064] Figure 2 Schematic diagram of the electromagnetic catapult device and timing trigger control system.

[0065] Figure 3 This is a schematic diagram of the connection structure between the launch tube segments of the electromagnetic catapult device.

[0066] Figure 4 This is a top-down schematic diagram of the expansion tank, test chamber, vacuum system and related measurement and control devices.

[0067] Description of Figure Numbers:

[0068] 1-Electromagnetic catapult; 101-Blocking; 102-Launch tube; 10201-Launch tube section k; 10202-Launch tube section k+1; 103-Drive coil; 104-Launch tube inter-section connection mechanism A; 10401-Insulating flange fitting Aa; 10402-Insulating flange fitting Ab; 10403-Insulating bolt assembly Ac; 105-Metal layer; 106-Excitation power supply; 10601-Energy storage pulse capacitor bank; 10602-Main switch; 10603-Freewheeling switch; 107-Charger; 10701-Charging switch; 2-Armature; 3-Model; 4-Expansion tank; 401-Expansion tank and vacuum system interface; 402-Expansion tank side observation window; 403-Expansion tank top observation window; 5-Test chamber ;501-Interface between test chamber and vacuum system;502-Observation window on the side of test chamber;503-Observation window on the top of test chamber;6-Vacuum mechanism;7-Measurement and control system;701-Central controller;702-Pulse trigger circuit;703-Laser Doppler armature speed measuring device;70301-Main equipment of armature speed measuring device;70302-Probe of armature speed measuring device;704-Excitation power supply voltage measuring device;705-Drive coil current measuring device;706-Model speed measuring device in expansion box;707-Binocular vision measurement system for expansion box;708-Model speed measuring device in test chamber;709-Test chamber schlieren instrument;710-Test chamber binocular vision measurement system;711-Test chamber light radiation measuring instrument;8-Support mechanism;9-Track system. DETAILED DESCRIPTION

[0069] The present invention will be described more clearly and completely below with reference to the accompanying drawings, and those skilled in the art will be able to implement the present invention based on these descriptions.

[0070] The word "exemplary" is used exclusively herein to mean "serving as an example, example, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

[0071] like Figure 1 and Figure 2As shown, an embodiment of the present application provides a large-caliber ballistic target driven by electromagnetic catapult, including an electromagnetic catapult device 1, an armature 2, a model 3, an expansion tank 4, a test chamber 5, a vacuum system 6 and a measurement and control system 7.

[0072] The electromagnetic catapult device 1 may include a launch tube 102, a multi-stage drive coil 103 wound around the launch tube 102, an excitation power supply 106 for supplying power to the multi-stage drive coil 103, and a charger 107 for charging the excitation power supply 106. In one embodiment, the charger 107 is an IGBT series resonant constant current charging power supply.

[0073] The launch tube 102 of the electromagnetic catapult device 1 can be connected to the expansion tank 4 and the test chamber 5 in sequence. The launch tube 102, the expansion tank 4, and the test chamber 5 are filled with a test gas. In one embodiment, the test gas filled in the launch tube 102, the expansion tank 4, and the test chamber 5 is air at a pressure of 10 Pa to 0.2 MPa.

[0074] The launch tube 102 houses the armature 2 and model 3, with the armature 2 positioned behind the model 3. The model 3 can be mounted on the armature 2. When the excitation power supply 106 is triggered, the multi-stage drive coils 103 discharge in stages, generating pulsed currents. This in turn generates a pulsed magnetic field, which in turn generates eddy currents within the armature 2 and exerts an electromagnetic force. This electromagnetic force causes the armature 2 to move and propel the model 3 at high speed. The model 3 then exits the launch tube 102, passes through the expansion tank 4, and enters the test chamber 5.

[0075] The launch tube 102 serves as a guide. In one embodiment, the launch tube 102 is made of an insulating material to prevent electrical conduction between the drive coil 103 and the armature 2, while also ensuring good electromagnetic induction between the drive coil 103 and the armature 2. The launch tube 102 has a maximum operating temperature of 260 degrees Celsius, ensuring that the temperature rise caused by the acceleration of the armature 2 is within the operating temperature range of the launch tube 102. The launch tube 102 has an inner diameter of no less than 50 mm to enable flight testing of models with a diameter of 50 mm or more. One end of the launch tube 102 is sealed by a plug 101, and the other end is connected to the expansion tank 4 via a flange.

[0076] In one embodiment, the conductors of the multi-stage drive coil 103 of the electromagnetic catapult device 1 are made of copper and are coated with an insulating material. The multi-stage drive coil 103 is entirely coated with a metal layer 105. Both ends of the metal layer 105 are fixed to the launch tube 102. The metal layer 105 provides electromagnetic shielding and structural reinforcement for the launch tube 102 and the multi-stage drive coil 103.

[0077] In one embodiment, the armature 2 is structured in the form of an integral solid cylinder or a hollow cylinder, and the material of the armature 2 is aluminum or an aluminum alloy.

[0078] In one embodiment, model 3 is a full-caliber model without a sabot or a combined model with a sabot. When model 3 is a full-caliber model without a sabot, after launch, model 3 enters expansion tank 4 and then test chamber 5. When model 3 is a combined model with a sabot, combined model 3 consists of a model body and a sabot. After launch, the sabot and model body separate within expansion tank 4, and the model body enters test chamber 5.

[0079] In one embodiment, the structural and electromagnetic parameters of each stage of the drive coils 103 and excitation power supply 106 are identical. This allows for the installation of multiple drive coils 103 and excitation power supplies 106 from the same batch outside the transmitting tube 102, reducing the cost of manufacturing and assembling the drive coils 103 and excitation power supplies 106. While maintaining the same hardware parameters, the excitation timing of each stage of the drive coils 103 can be controlled by software to accommodate flight tests of different models.

[0080] In one embodiment, Figure 2 As shown, the number of stages of the multi-stage drive coils 103 of the electromagnetic catapult device 1 is n, where n ≥ 3. Under the conditions of the set basic parameters such as the piston peak velocity, average acceleration, and pump tube diameter, the acceleration length, electrical energy-to-kinetic energy conversion efficiency, and expected total energy are reasonably estimated. Furthermore, the number of stages of the drive coils 103 is determined after comprehensive consideration, taking into account the extreme parameters of the single-stage drive coils and the excitation power supply (voltage resistance, current resistance, stress, temperature rise, equipment cost, etc.), to achieve efficient and safe acceleration of the armature 2 and piston 3. If the number of stages of the drive coils 103 is too small, the energy per stage is too large, affecting the safety, technical difficulty, and cost of the drive coils 103 and the excitation power supply 106. If the number of stages of the drive coils 103 is too large, the energy per stage is too small and the acceleration length is too long, which is not conducive to achieving efficient and rapid acceleration of the armature 2 and significantly increases the equipment footprint and equipment cost.

[0081] In one embodiment, the ratio of the length of each stage of the drive coil 103 of the electromagnetic catapult device 1 to the inner diameter of the launch tube 102 is 0.4 to 1.7, and the ratio of the distance between the facing end faces of adjacent stages of the drive coil 103 to the inner diameter of the launch tube 102 is 0.1 to 0.3. By properly setting the length of the drive coil 103, the mutual inductance gradient and overall driving capacity of the drive coil 103 and the armature 2 are beneficially kept within a reasonable range.

[0082] In one embodiment, Figure 2As shown, each stage of the electromagnetic catapult device 1 is connected to an independent excitation power supply 106. The excitation power supply 106 includes an energy storage pulse capacitor bank 10601, a main switch 10602, and a freewheeling switch 10603. The energy storage pulse capacitor bank 10601 can be connected in series with the main switch 10602 and connected in parallel with the freewheeling switch 10603 at both ends of the drive coil 103. The two ends of the energy storage pulse capacitor bank 10601 are also connected to the two ends of the charger 107 through a charging switch 10701.

[0083] The charger 107 is connected to the energy storage pulse capacitor bank 10601 via a charging switch 10701. Before the excitation power supply 106 is activated, the charging switch 10701 is turned on, and the charger 107 charges the energy storage pulse capacitor bank 10601. When the energy storage pulse capacitor bank 10601 reaches a predetermined voltage, the charging switch 10701 is turned off, and the charger 107 stops charging.

[0084] The excitation power source 106 is controlled by a timing trigger method through the measurement and control system 7 to achieve step-by-step discharge of the excitation power source 106. The measurement and control system 7 can monitor the voltage information of the excitation power source 106, the current information of the drive coil, the motion information of the transmitting tube 102, the expansion tank 4, the armature 2 and the model 3 in the test chamber 5, and the aerodynamic / thermal information, aerodynamic physical parameter information, or high-speed collision parameter information of the model 3 in the test chamber 5 through sensors.

[0085] The measurement and control system 7 includes a central controller 701, a pulse trigger circuit 702, and a laser Doppler armature speed measuring device 703. The laser Doppler armature speed measuring device 703 comprises an armature speed measuring device body 70301 and an armature speed measuring device probe 70302. The armature speed measuring device probe 70302 is mounted at the end of the transmitting tube 102, at the tube plug 101. The armature speed measuring device body 70301 and the armature speed measuring device probe 70302 are connected via an optical fiber. The armature speed measuring device body 70301 transmits a laser signal to the armature 2 via the armature speed measuring device probe 70302 and receives the laser signal reflected from the armature 2. The laser signal is converted into an electrical signal and transmitted to the central controller 701. The central controller 701 processes the electrical signal to determine the position and instantaneous velocity of the armature 2 at each moment and, through a pre-set program, calculates the estimated triggering time of the triggering stage. At the expected triggering moment, the central controller 701 sends a trigger control signal to the pulse triggering circuit 702, and the pulse triggering circuit 702 outputs a power pulse to trigger the main switch 10602 to turn on.

[0086] When the main switch 10602 is turned on, the energy storage pulse capacitor bank 10601 can supply power to the drive coil 103. When the voltage of the energy storage pulse capacitor bank 10601 drops to zero, the freewheeling switch 10603 turns on, the main switch 10602 turns off, and the drive coil 103 continues to flow through the freewheeling switch 10603 until the discharge current drops to zero. Each level of the excitation power supply operates in a similar manner. This prevents reverse charging of the energy storage pulse capacitor bank 10601 and improves its service life.

[0087] Furthermore, the energy storage pulse capacitor group 10601 is composed of a combination of metallized film self-healing pulse capacitors, and the energy volume ratio of the metallized film self-healing pulse capacitor is greater than or equal to 0.5MJ / m 3 , working life is greater than or equal to 1000 times.

[0088] Furthermore, the main switch 10602 is a spark gap switch or a high-voltage switch composed of a semiconductor thyristor.

[0089] Furthermore, the freewheeling switch 10603 is composed of a combination of semiconductor high-voltage diodes.

[0090] like Figure 2 As shown, the measurement and control system 7 may further include an excitation power supply voltage measuring device 704 and a drive coil current measuring device 705. The excitation power supply voltage measuring device 704 may be used to monitor the voltage of the energy storage pulse capacitor bank 10601. The drive coil current measuring device 705 may be used to monitor the current of the drive coil 103.

[0091] Example of the connection mechanism A104 between launch tube segments:

[0092] Due to limitations in the manufacturing process, launch tubes of the same specification are usually limited in length, and a launch tube segment connection mechanism A104 is required to connect the segments of tubes of the same specification to each other. The launch tube segment connection mechanism A104 adopts a flange connection structure, a half nut connection structure, or a half clamp connection structure.

[0093] like Figure 3 As shown, the adjacent launch tube sections k 10201 and k+1 10202 are connected using insulating flanges. Insulating flange fittings Aa10401 with a concave stop and Ab10402 with a convex stop are bonded to launch tube sections k 10201 and k+1 10202, respectively. Insulating flange fittings Aa10401 and Ab10402 are secured together by insulating bolt assemblies Ac10403.

[0094] In one embodiment, the expansion tank 4 and the test chamber 5 are connected to a vacuum system 6 , and the air pressure in the expansion tank 4 and the test chamber 5 is 10 Pa to 0.2 MPa.

[0095] In one embodiment, the expansion tank 4 and the test chamber 5 are provided with multiple optical windows, and are equipped with a model velocity measurement system, a camera system for measuring the model position and posture, a schlieren instrument for flow field display, and a light radiation measurement system for measuring light radiation characteristics.

[0096] Expansion tank 4, test chamber 5, vacuum system 6 and related measurement and control devices embodiment:

[0097] like Figure 4 As shown, the expansion tank 4 and test chamber 5 are connected to the vacuum system 6 via interfaces 401 and 501 with the vacuum system, respectively. The vacuum system 6 regulates the air pressure within the expansion tank 4 and test chamber 5 to the desired pressure, which ranges from 10 Pa to 0.2 MPa. Multiple in-chamber model velocity measurement devices 706 are installed on the side of the expansion tank 4. The expansion tank 4 is equipped with multiple side optical windows 402 and a top optical window 403, and is equipped with an expansion tank binocular vision measurement system 707 for measuring the model's flight attitude or the dynamic process of separation between the combined model sabot and the model body. The test chamber 5 is equipped with multiple in-chamber model velocity measurement devices 708. A schlieren instrument 709 is installed in the test chamber 5 for flow field visualization. The test chamber 5 is equipped with multiple side optical windows 502 and a top optical window 503, and is equipped with a binocular vision measurement system 710 for measuring the model's flight attitude and an optical radiation measurement system 711 for measuring optical radiation characteristics.

[0098] In one embodiment, Figure 1 As shown, the ballistic target includes several supporting mechanisms 8 and a track system 9. The several supporting mechanisms 8 are respectively located under the launch tube 102, the expansion tank 4 and the test chamber 5. The supporting mechanisms 8 are installed on the track system 9 and can move along the track.

[0099] The working principle of the present invention is as follows:

[0100] Before the test, the armature 2 is placed in an appropriate position at the inlet of the launch tube 102 (preferably, the rear end of the armature 2 is aligned with the center line of the first-stage drive coil 103). The charger 107 pre-charges the energy storage pulse capacitor bank 10601 to a certain voltage. The launch tube 102, expansion tank 4, and test chamber 5 are pre-filled with a certain pressure of test gas (e.g., air at a pressure of 10Pa to 0.2MPa).

[0101] During the test, the main switch of the first-stage excitation power supply 106 is triggered, causing the first-stage energy storage pulse capacitor bank to discharge through the first-stage drive coil. After the voltage of the first-stage energy storage pulse capacitor bank drops to zero, the first-stage drive coil continues to flow through the first-stage freewheeling switch. The pulsed magnetic field generated by the pulsed current generates eddy currents in the armature 2, which, under the action of electromagnetic force, propels the model 3 forward. A laser Doppler armature velocimeter 703 transmits a laser signal at a specific frequency to the armature 2 and receives the laser signal reflected from the armature 2. It converts the laser signal into an electrical signal and transmits it to the central controller 701. The central controller 701 processes the electrical signal to determine the position and instantaneous velocity of the armature 2 at each moment and calculates the estimated trigger time for the second stage. Based on the estimated trigger time for the second stage, the central controller 701 sends a trigger control signal to the pulse trigger circuit 702 after a specific delay. The pulse trigger circuit 702 outputs a power pulse to turn on the main switch of the second-stage excitation power supply 106, causing the second-stage energy storage pulse capacitor bank to discharge through the second-stage drive coil. After the voltage of the second-stage energy storage pulse capacitor group drops to zero, the second-stage drive coil continues to flow through the second-stage freewheeling switch. The pulse magnetic field jointly excited by the first stage (if the first stage discharge has not ended) and the second stage causes the armature 2 to generate eddy currents and, under the action of electromagnetic force, pushes the model 3 to continue moving forward. Similarly, the excitation power supply 106 discharges pulse currents step by step through the drive coil 103, thereby generating a pulse magnetic field, causing eddy currents to be generated inside the armature 2 and subjected to electromagnetic force. Under the action of electromagnetic force, the armature 2 moves and pushes the model 3 to be launched at high speed and fly out of the launch tube 102. When the model 3 is a full-caliber model without a sabot, it passes through the expansion tank 4 after launch and enters the test chamber 5. When the model 3 is a combined model with a sabot, the sabot and the model body are separated in the expansion tank 4, and the model body enters the test chamber 5.

[0102] When the armature 2 and the model 3 pass through the drive coil 103 near the side of the blocker 101, the movement speed of the armature 2 and the model 3 can be relatively slow. When the armature 2 and the model 3 pass through the drive coil 103 near the side of the expansion tank 4, the movement speed of the armature 2 and the model 3 can be relatively fast. The embodiment of the present application provides an optimized timing trigger control method, which enables the multi-stage drive coil 103 to be excited in a timed manner. Therefore, when the armature 2 passes through each stage of the drive coil 103, it can be efficiently driven by the corresponding drive coil 103, and a higher model launch speed can be achieved. The specific steps are as follows.

[0103] (1) For an n-stage electromagnetic catapult device with the same parameters at each stage, before starting, the rear end surface of the armature 2 is placed at an appropriate position near the center line of the first-stage drive coil. Preferably, the rear end surface of the armature 2 is aligned with the center line of the first-stage drive coil.

[0104] (2) The central controller 701 triggers the first-stage excitation power supply 106-1 through the pulse trigger circuit 702, and at the same time, the laser Doppler armature speed measuring device 703 emits laser along the movement direction of the armature 2. This time is taken as time 0, that is, the triggering time of the first-stage excitation power supply 106-1 is t1=0.

[0105] (3) The armature 2 moves forward, and the central controller 701 triggers the second-stage excitation power supply 106-2 to turn on at time t2 through the pulse trigger circuit 702. At time t2, the following conditions are met: m <t2<2t m , where t m is the time interval when the discharge current of the driving coil 103 rises from zero to the maximum value, L d is the sum of all self-inductances of the first-stage discharge circuit before freewheeling, and C is the capacitance of the energy storage pulse capacitor bank. Simultaneously, the laser Doppler armature speed measuring device 703 and the central controller 701 measure and process the position and speed of the armature 2 at time t2.

[0106] (4) The armature 2 continues to move forward, and the central controller 701 triggers the third-stage excitation power supply to be turned on at time t3 through the pulse trigger circuit 702. At time t3, the following conditions are satisfied:

[0107] Wherein, v2 is the speed of armature 2 at time t2, a is the average acceleration of armature 2, h is the center distance between two adjacent driving coils 103, t m It is the time interval when the discharge current of the driving coil 103 rises from zero to the maximum value.

[0108] (5) Similarly, the armature 2 continues to move forward, and the central controller 701 triggers the pulse circuit 702 at time t i+1 Triggering the conduction of the i+1th level excitation power supply, time t i+1 satisfy:

[0109] Among them, v i is time t i Armature 2 speed, a is the average acceleration of armature 2 movement, h is the center distance between two adjacent drive coils 103, t m It is the time interval when the discharge current of the driving coil 103 rises from zero to the maximum value.

[0110] (6) In the above steps, the armature 2 speed v at each triggering moment i The laser Doppler armature speed measuring device 703 measures and the central controller 701 processes and solves the signal to obtain t mIt is calculated by the structural parameters and electromagnetic parameters of the given circuit, where h is the given structural parameter and a is reasonably estimated based on the maximum electromagnetic force of the single-stage coil pushing the armature 2 and the model 3 to move. Specifically, the maximum acceleration of the armature 2 and the model 3 in the first-stage drive coil and the second-stage drive coil can be obtained through simulation or experiment. This acceleration can be related to the total mass of the armature 2 and the model 3. Through the above steps, the optimal multi-stage trigger timing [t1, t2, t3, ... t i ,t i+1 ,…t n ], which can achieve higher electrical energy-kinetic energy conversion efficiency.

[0111] The present invention has been described in detail above with reference to specific embodiments and exemplary embodiments. However, these descriptions and embodiments are merely illustrative and not restrictive, and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art will appreciate that, without departing from the spirit and scope of the present invention, various equivalent substitutions, modifications, or improvements may be made to the technical solutions of the present invention and their implementations, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the appended claims. Contents not described in detail in the present specification belong to the common knowledge of those skilled in the art.

Claims

1. A large-caliber ballistic target driven by electromagnetic catapult, characterized in that: Used for performing flight measurement of a model (3), the large-caliber ballistic target comprises an electromagnetic ejection device (1), an armature (2), an expansion tank (4), a test chamber (5) and a measurement and control system (7); wherein, The electromagnetic catapult device (1) comprises a launch tube (102), a multi-stage drive coil (103) wound on the launch tube (102), an excitation power supply (106) for supplying power to the multi-stage drive coil (103), and a charger (107) for charging the excitation power supply (106); The launch tube (102), the expansion tank (4) and the test chamber (5) are connected in sequence. The launch tube (102) contains the armature (2) and the model (3). The model (3) is mounted on the armature (2). The inner diameter of the launch tube (102) is not less than 50 mm. Each stage of the driving coil (103) is connected to an independent excitation power supply (106), and the excitation power supply (106) is triggered step by step to discharge the multi-stage driving coil (103) step by step. The armature (2) moves under the action of the electromagnetic force generated by the multi-stage driving coil (103) and pushes the model (3). The model (3) flies out of the launch tube (102), passes through the expansion tank (4), and enters the test chamber (5). The measurement and control system (7) is used to determine the triggering time of each level of the excitation power supply (106) according to the moving speed and position of the armature (2); The measurement and control system (7) includes a central controller (701), a pulse trigger circuit (702) and a laser Doppler armature speed measuring device (703); The laser Doppler armature speed measuring device (703) comprises an armature speed measuring device main body (70301) and an armature speed measuring device probe (70302), wherein the armature speed measuring device probe (70302) is installed at a pipe opening sealing portion at one end of the transmitting tube (102), and the armature speed measuring device main body (70301) and the armature speed measuring device probe (70302) are connected via an optical fiber; The armature speed measuring device main body (70301) transmits a laser signal to the armature (2) through the armature speed measuring device probe (70302) and receives the laser signal reflected from the armature (2), and converts the laser signal into an electrical signal and transmits it to the central controller (701); The central controller (701) processes the electrical signal to obtain the position and instantaneous speed of the armature (2) at each moment, and obtains the expected triggering moment of the excitation power supply (106) to be triggered; At the predicted triggering moment, the central controller (701) sends a trigger control signal to the pulse triggering circuit (702), and the pulse triggering circuit (702) outputs a power pulse to trigger the corresponding stage excitation power supply (106) to be turned on; The central controller (701) is used to execute a timing trigger control method, which includes: Step 1: i = 1, at time t i＝1 =0 triggers the first-stage excitation power supply to be turned on, and simultaneously controls the laser Doppler armature speed measuring device (703) to emit laser light along the moving direction of the armature (2); Step 2: i = 2, at time t i＝2 Triggering the conduction of the second stage excitation power supply, the time t2 satisfies: t m <t2<2t m , where t m is the time interval when the discharge current of the driving coil rises from zero to the maximum value; at the same time, the laser Doppler armature speed measuring device (703) is controlled to perform measurement to obtain the position and speed of the armature (2) at time t2; Step 3: Loop through the following steps 3-1 and 3-2 until the moment t at which the n-th stage excitation power supply is turned on is obtained. n : Step 3-1: At time t i+1 Triggering the conduction of the i+1th level excitation power supply, the time t i+1 satisfy: v i is time t i Armature speed, a is the average acceleration of armature motion, h is the center distance between two adjacent drive coils; Step 3-2: Let i=i+1.

2. The large-caliber ballistic target according to claim 1, characterized in that: The multi-stage driving coil (103) satisfies at least one of the following: The number of stages of the multi-stage driving coil (103) is n, where n≥3; The structural parameters and electromagnetic parameters of the driving coils (103) and the excitation power supply (106) at each level are the same; The ratio of the length of each stage driving coil (103) to the inner diameter of the transmitting tube (102) is 0.4 to 1.7; The ratio of the distance between the facing end faces of the adjacent-stage driving coils (103) to the inner diameter of the transmitting tube (102) is 0.1 to 0.3; The conductor of the driving coil (103) is made of copper, and the conductor of the driving coil (103) is covered with insulating material. The exterior of the multi-stage driving coil (103) is entirely covered by a metal layer.

3. The large-caliber ballistic target according to claim 1, characterized in that: The excitation power supply (106) comprises an energy storage pulse capacitor group (10601), a main switch (10602), and a freewheeling switch (10603); the energy storage pulse capacitor group (10601) is connected in series with the main switch (10602), and is connected in parallel with the freewheeling switch (10603) at both ends of the driving coil (103); the two ends of the energy storage pulse capacitor group (10601) are also connected to the two ends of the charger (107) via a charging switch (10701); the on and off of the main switch (10602) and the charging switch (10701) are controlled by the measurement and control system (7).

4. The large-caliber ballistic target according to claim 3, characterized in that: The excitation power supply (106) satisfies at least one of the following: The energy storage pulse capacitor group (10601) is composed of a combination of metallized film self-healing pulse capacitors, and the energy volume ratio of the metallized film self-healing pulse capacitor is greater than or equal to 0.5MJ / m 3 , working life is greater than or equal to 1000 times; The main switch (10602) is a spark gap switch or a high-voltage switch composed of a semiconductor thyristor; The freewheeling switch (10603) is composed of a combination of semiconductor high-voltage diodes.

5. The large-caliber ballistic target according to claim 1, characterized in that: t m according to OK, L d is the sum of all self-inductances of the first-stage discharge circuit, and C is the capacitance of the energy storage capacitor group.

6. The large-caliber ballistic target according to claim 1 or 5, characterized in that: Before starting, the rear end surface of the armature (2) is aligned with the center line of the first-stage driving coil (103).

7. The large-caliber ballistic target according to claim 1, characterized in that: The transmitting tube (102) satisfies at least one of the following: The transmitting tube (102) is made of insulating material; The maximum operating temperature of the launch tube (102) is 260 degrees Celsius; One pipe opening of the launch tube (102) is sealed by a plug, and the other pipe opening is connected to the expansion tank (4) via a flange; When the launch tubes (102) need to be connected to each other in sections using pipes of the same specification, each section of the launch tubes (102) is connected using a flange structure, a half nut structure, or a half clamp structure.

8. The large-caliber ballistic target according to claim 1, characterized in that: The large-caliber ballistic target satisfies at least one of the following: The armature (2) is in the form of an integral solid cylinder or a hollow cylinder, and the armature (2) is made of aluminum or an aluminum alloy. The charger (107) is an IGBT series resonant constant current charging power supply; The test gas filled in the launch tube (102), the expansion tank (4), and the test chamber (5) is air, and the air pressure is 10 Pa to 0.2 MPa; The model (3) is a full-caliber model without a buttstock or a combined model with a buttstock; when the model (3) is a full-caliber model without a buttstock, the model (3) enters the test chamber (5) through an expansion box (4) after being launched; when the model (3) is a combined model with a buttstock, the combined model consists of a model (3) body and a buttstock; after the model (3) is launched, the buttstock and the model body are separated in the expansion box (4), and the model body enters the test chamber (5); The expansion tank (4) and the test chamber (5) are connected to a vacuum system, and a plurality of optical windows are provided on the top and the side; The expansion tank (4) and the test chamber (5) are equipped with a plurality of measuring devices, including a model (3) velocity measurement system, a camera system for measuring the position and posture of the model (3), a shadow / schlieren instrument for displaying the flow field, and a light radiation measurement system for measuring light radiation characteristics; The ballistic target comprises several supporting mechanisms and a track system. The supporting mechanisms are respectively located below the launch tube (102), the expansion tank (4) and the test chamber (5). The supporting mechanisms are installed on the track system and can move along the track.

9. A timing trigger control method, characterized in that: The method is applied to a large-caliber ballistic target driven by an electromagnetic catapult, wherein the large-caliber ballistic target is used to perform flight measurement of a model (3), and the large-caliber ballistic target comprises an electromagnetic catapult device (1), an armature (2), an expansion tank (4), a test chamber (5), and a measurement and control system (7); wherein, The electromagnetic catapult device (1) comprises a launch tube (102), a multi-stage drive coil (103) wound on the launch tube (102), an excitation power supply (106) for supplying power to the multi-stage drive coil (103), and a charger (107) for charging the excitation power supply (106); The launch tube (102), the expansion tank (4) and the test chamber (5) are connected in sequence. The launch tube (102) contains the armature (2) and the model (3). The model (3) is mounted on the armature (2). The inner diameter of the launch tube (102) is not less than 50 mm. Each stage of the driving coil (103) is connected to an independent excitation power supply (106), and the excitation power supply (106) is triggered step by step to discharge the multi-stage driving coil (103) step by step. The armature (2) moves under the action of the electromagnetic force generated by the multi-stage driving coil (103) and pushes the model (3). The model (3) flies out of the launch tube (102), passes through the expansion tank (4), and enters the test chamber (5). The measurement and control system (7) is used to determine the triggering time of each level of the excitation power supply (106) according to the moving speed and position of the armature (2); The measurement and control system (7) includes a central controller (701), a pulse trigger circuit (702) and a laser Doppler armature speed measuring device (703); The laser Doppler armature speed measuring device (703) comprises an armature speed measuring device main body (70301) and an armature speed measuring device probe (70302), wherein the armature speed measuring device probe (70302) is installed at a pipe opening sealing portion at one end of the transmitting tube (102), and the armature speed measuring device main body (70301) and the armature speed measuring device probe (70302) are connected via an optical fiber; The armature speed measuring device main body (70301) transmits a laser signal to the armature (2) through the armature speed measuring device probe (70302) and receives the laser signal reflected from the armature (2), and converts the laser signal into an electrical signal and transmits it to the central controller (701); The central controller (701) processes the electrical signal to obtain the position and instantaneous speed of the armature (2) at each moment, and obtains the expected triggering moment of the excitation power supply (106) to be triggered; At the predicted triggering moment, the central controller (701) sends a trigger control signal to the pulse triggering circuit (702), and the pulse triggering circuit (702) outputs a power pulse to trigger the corresponding stage excitation power supply (106) to be turned on; The method comprises: Step 1: i = 1, at time t i＝1 =0 triggers the first-stage excitation power supply to be turned on, and simultaneously controls the laser Doppler armature speed measuring device (703) to emit laser light along the moving direction of the armature (2); Step 2: i = 2, at time t i＝2 Triggering the conduction of the second stage excitation power supply, the time t2 satisfies: t m <t2<2t m , where t m is the time interval from when the discharge current of the driving coil changes from zero to when it reaches the maximum value; at the same time, the laser Doppler armature speed measuring device (703) is controlled to perform measurement to obtain the position and speed of the armature (2) at time t2; Step 3: Loop through the following steps 3-1 and 3-2 until the moment t at which the n-th stage excitation power supply is turned on is obtained. n : Step 3-1: At time t i+1 Triggering the conduction of the i+1th level excitation power supply, the time t i+1 satisfy: v i is time t i Armature speed, a is the average acceleration of armature motion, h is the center distance between two adjacent drive coils; Step 3-2: Let i=i+1.

Images