CN116086241A - Ballistic target based on electromagnetic ejection auxiliary driving primary gas gun - Google Patents

Abstract

The invention provides a ballistic target based on electromagnetic ejection auxiliary driving primary gas cannon, which comprises a high-pressure gas propulsion section, an armature, a model, an electromagnetic ejection device, an expansion tank, a test cabin and a measurement and control system, wherein the armature is arranged on the high-pressure gas propulsion section; the electromagnetic ejection device comprises an electromagnetic emission tube, a multi-stage driving coil, an excitation power supply and a charger; the high-pressure gas propulsion section comprises a high-pressure air chamber and a high-pressure gas gun barrel; the high-pressure air chamber, the high-pressure air gun barrel, the electromagnetic emission pipe, the expansion tank and the test cabin are sequentially connected. The high-pressure air chamber releases high-pressure air to drive the armature and the model to move in the high-pressure air gun barrel; and then the armature drives the model to fly out of the electromagnetic emission pipe at high speed under the combined action of aerodynamic force and electromagnetic force provided by the electromagnetic ejection device, and the model enters the test cabin through the expansion tank. The invention adopts high-pressure gas and electromagnetic ejection composite primary driving, obviously enhances driving capability, can improve emission speed or equipment caliber and test model size, and can optimize and improve inner trajectory performance to realize soft emission.

Description

A ballistic target based on electromagnetic ejection auxiliary drive of first-stage gas gun

Technical Field

The present application relates to the technical field of ultra-high-speed flight ground simulation tests, and in particular to a ballistic target based on electromagnetic ejection-assisted driving of a first-stage gas cannon.

Background Art

The ballistic target is an aerodynamic ground test device that enables the aerodynamic test model to fly freely in static gas. It can simulate real flight flow conditions and is used to carry out aerodynamic/thermal, aerodynamic physics, hypervelocity collision and other test tests. Based on the scale effect of model flight ground simulation tests, under the same other conditions, the closer the model size is to the aircraft prototype size, the closer the ground simulation data results are to reality. Under the same launch speed conditions, the larger the caliber of the launch device and the larger the model size, the better the simulation test effect.

The ballistic target is mainly composed of a model launch device, a test system and a measurement and control system. The power source of the ballistic target launch device is usually gunpowder, compressed gas or hydrogen-oxygen detonation. The structure mainly includes a first-stage gun, a second-stage light gas gun, a third-stage light gas gun and other configurations. The second-stage light gas gun driven by gunpowder is the most common. The second-stage light gas gun can accelerate the projectile to a maximum of 8km/s, but the caliber of the launch tube is usually less than 50mm (maximum no more than 210mm); the third-stage light gas gun can accelerate the projectile to a maximum of about 11km/s, but the caliber of the launch tube is usually less than 20mm. At present, the second/third-stage light gas guns cannot meet the needs of large-size (caliber 50mm or more) model flight ground tests under ultra-high speed (8km/s and above) conditions.

Compared with the second/third stage light gas gun, the first stage gun usually has a caliber of more than 50mm, and under the same firing speed conditions, it can achieve better ground simulation test results. Gunpowder, hydrogen-oxygen detonation and other methods have problems such as poor safety, environmental pollution, and policy control, which limit their application; while the high-pressure gas drive method is safe and clean, but its initial injection pressure is limited by the capacity of the injection equipment, and there is also an inherent problem of rapid decrease in the bottom pressure of the projectile after the projectile is launched, which cannot provide a high average pressure for the projectile, and the internal ballistic performance is poor and the driving ability is weak. In short, due to the insufficient driving capacity of the traditional power source or safety reasons, the firing speed of the first stage gun generally does not exceed 2km/s.

Therefore, the hypervelocity ballistic target urgently needs a new power source with strong driving force, high safety and excellent internal ballistic performance. The coil-type electromagnetic catapult device has the characteristics of multi-stage axial distribution of electromagnetic coils, graded modular empowerment, and single-stage independent adjustment, which can achieve excellent and controllable internal ballistic performance. China Patent Publication No. CN108759559A, Publication Date November 6, 2018, the name of the invention is: a two-stage light gas gun, the application discloses a two-stage light gas gun with an electromagnetic gun as the first-stage drive, which is safer than gunpowder drive, mixed gas detonation and other methods, and occupies less space and has a higher firing speed than high-pressure nitrogen drive. However, due to the structure of the two-stage light gas gun, although a higher firing speed can be achieved, its disadvantage is that the launch tube has a small caliber (such as: the launch tube diameter of its embodiment is only 14mm), and the size and mass of the test model are small, which cannot meet the requirements of large-scale model ultra-high-speed flight simulation test.

Summary of the invention

In order to solve the problems of weak driving ability, small caliber and unsatisfactory internal ballistic performance of existing ballistic target launching devices, the present invention explores the potential of the driving mode of the electromagnetic catapult device and provides a large-caliber ballistic target of the launching device by using a first-stage gun with a high-pressure gas and electromagnetic catapult composite drive, so as to ensure that the size of the test model is increased under the condition of ultra-high-speed launching, and at the same time improve the internal ballistic performance, so as to provide a safe, clean, efficient and controllable large-caliber test platform for tests such as aerodynamic/thermal, aerodynamic physics and ultra-high-speed collision.

In the first aspect, a ballistic target based on electromagnetic ejection auxiliary driving a first-stage gas cannon is provided, which is used to perform flight measurement of a model, and the ballistic target includes a high-pressure gas propulsion section, an armature, a model, an electromagnetic ejection device, an expansion tank, a test chamber and a measurement and control system; wherein,

The high-pressure gas propulsion section includes a high-pressure gas chamber and a high-pressure gas gun tube, wherein the high-pressure gas gun tube is equipped with the armature and the model, and the armature is behind the model;

The electromagnetic ejection device comprises an electromagnetic launch tube, a multi-stage drive coil wound on the electromagnetic launch tube, an excitation power supply for supplying power to the multi-stage drive coil, and a charger for charging the excitation power supply, and the high-pressure gas chamber, the high-pressure gas gun tube, the electromagnetic launch tube, the expansion tank and the test chamber are connected in sequence;

The high-pressure gas chamber releases gas to drive the armature and the model to move forward and fly out of the high-pressure gas gun tube. In the electromagnetic launch tube, the armature pushes the model under the combined drive of gas thrust and electromagnetic force, and the model flies out of the launch tube and passes through the expansion box into the test chamber;

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

In conjunction with the first aspect, in certain implementations of the first aspect, the high-pressure gas propulsion section satisfies at least one of the following:

The gas in the high-pressure gas chamber is air, nitrogen or helium, and the gas pressure is not greater than 30 MPa;

The high-pressure gas chamber is connected to the high-pressure gas gun barrel via a flange structure or an open sawtooth thread structure;

The total pressure P _1x and total temperature T _1x of the gas in the high-pressure gas chamber after the gas in the high-pressure gas chamber is released are expressed as follows:

其中，γ₁为气体比热比，P₁₀为气体初始压力，T₁₀为气体初始温度，V₁₀为气体初始体积，x为电枢运动的距离，D为电磁发射管内径，V_1x(x)为电枢运动x距离时气体体积；

Where, γ ₁ is the specific heat ratio of the gas, P ₁₀ is the initial pressure of the gas, T ₁₀ is the initial temperature of the gas, V ₁₀ is the initial volume of the gas, x is the distance moved by the armature, D is the inner diameter of the electromagnetic transmitting tube, and V _1x (x) is the volume of the gas when the armature moves x distance;

The high-pressure gas chamber includes a release mechanism, and the release mechanism is a piston-type release mechanism or a double-break film-type release mechanism;

The ratio of the volume of the high-pressure gas gun barrel to the volume of the high-pressure gas chamber is ≥ 1.0;

The high-pressure gas gun barrel is made of gun steel.

In conjunction with the first aspect, in some implementations of the first aspect, the electromagnetic catapult device satisfies at least one of the following:

The electromagnetic transmitting tube is made of resin-based composite material or ceramic material, and the maximum operating temperature can reach 260 degrees Celsius;

The number of the multi-stage driving coils of the electromagnetic ejection device is n, where n≥3;

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

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

The ratio of the distance between adjacent end faces of adjacent stage driving coils to the inner diameter of the electromagnetic transmitting tube is 0.1 to 0.3;

The driving coil conductor of the electromagnetic ejection device is made of copper material, and the outside of the driving coil conductor is covered with insulating material;

The exterior of the multi-stage driving coil is entirely covered by a metal layer.

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.

In combination with the first aspect, in some implementations of the first aspect, the excitation power supply satisfies at least one of the following:

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

The main switch is a spark gap switch or a high voltage switch composed of a semiconductor thyristor;

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

In combination 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 an armature speed measuring device;

The armature speed measuring device comprises a photoelectric sensor body and a plurality of photoelectric probes, wherein the plurality of photoelectric probes are installed on the high-pressure gas gun tube and the electromagnetic launch tube wall at intervals along the movement direction of the armature, and the photoelectric sensor body is connected to the photoelectric probes via optical fibers;

The photoelectric probe sends a pulse light signal to the armature through the through holes on the wall of the high-pressure gas gun tube and the electromagnetic transmitting tube and receives the reflected light signal. The photoelectric sensor body converts the light signal into an electrical signal and transmits it to the central controller.

The central controller processes the electrical signal to obtain the time and speed of the armature passing through the photoelectric probe, and calculates the estimated triggering time of the to-be-triggered stage according to the timing triggering control method;

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 conduction of the excitation power supply of the to-be-triggered stage, so that the energy storage pulse capacitor group of the excitation power supply of the to-be-triggered stage discharges through the driving coil.

In combination with the first aspect, in certain implementations of the first aspect, the photoelectric probe is used to detect the rear end of the armature.

所述电枢在电磁发射管内第1级驱动线圈中心线处速度为v_za，t_m为驱动线圈放电电流从零上升至最大值时的时间间隔；In combination with the first aspect, in some implementations of the first aspect, at least m photoelectric probes G _f1 , G _f2 , ..., G _fi-1 , G _fi , ..., G _fm-1 , G _fm are evenly arranged axially backward from the center line of the first-stage driving coil, the axial spacing between the first photoelectric probe G _f1 and the center line of the first-stage driving coil is h/2, and the axial spacing between adjacent photoelectric probes is h.

The speed of the armature at the center line of the first-stage driving coil in the electromagnetic transmitting tube is v _za , and t _m is the time interval when the discharge current of the driving coil rises from zero to the maximum value;

At least n photoelectric probes _Gz1 , _Gz2 , ..., _Gzj , Gzj ₊₁ , ..., _Gzn-1 , _Gzn are evenly arranged axially forward from the center line of the first-level driving coil. The first photoelectric probe _Gz1 is located on the tube wall between the first-level driving coil and the second-level driving coil. The distance between the first photoelectric probe _Gz1 and the center line of the first-level driving coil is equal to the distance between the first photoelectric probe _Gz1 and the center line of the second-level driving coil. The axial interval between adjacent photoelectric probes is h.

In combination with the first aspect, in some implementations of the first aspect,

确定，L_d为驱动线圈放电电流经二级管续流之前的放电回路所有自感之和，C为储能电容器组电容值。In combination with the first aspect, in some implementations of the first aspect, t _m is based on

It is determined that _Ld is the sum of all self-inductances of the discharge circuit before the discharge current of the driving coil is freewheeling through the diode, and C is the capacitance value of the energy storage capacitor group.

In combination with the first aspect, in some implementations of the first aspect, the timing trigger control method includes:

Step 1: The high-pressure gas chamber releases gas to drive the armature to push the model forward;

Step 2: Let s = 1. When the armature moves past the mth photoelectric probe behind the center line of the first-stage drive coil, i = m. Circulate the following steps 2-1 and 2-2 until the first-stage excitation power supply is triggered:

Step 2-1: When the armature moves past the ith photoelectric probe behind the center line of the first-stage drive coil, the distance between the armature and the center line of the first-stage drive coil is l _fi1 =(i-1/2)h. The armature speed measuring device performs measurement and the central controller performs signal processing to obtain the armature speed v _fi at this moment and this position;

Step 2-2:

则在延迟时间Δt₁后触发第1级激励电源，所述延迟时间Δt₁满足：

令s＝s+1，令i＝i-1，跳转出本循环执行步骤3；if

Then the first stage excitation power supply is triggered after a delay time Δt ₁ , and the delay time Δt ₁ satisfies:

Let s=s+1, let i=i-1, jump out of this loop and execute step 3;

则不准备触发任何激励电源，令i＝i-1；if

Then no excitation power supply is to be triggered, and i=i-1;

Step 3: Circulate the following steps 3-1 and 3-2 until the armature passes the first photoelectric probe behind the center line of the first-stage drive coil and passes the center line of the first-stage drive coil;

Step 3-1: When the armature moves to the i-th photoelectric probe behind the center line of the first-stage drive coil, the distance between the armature and the center line of the s-th-stage drive coil is l _fis =(i+s-3/2)h. The armature speed measuring device performs measurement and the central controller performs signal processing to obtain the armature speed v _fi at this moment and this position;

Step 3-2:

则立即触发第s级激励电源，令s＝s+1，令i＝i-1；if

Then the s-th level excitation power supply is triggered immediately, let s = s + 1, let i = i - 1;

则在延迟时间Δt_s后触发第s级激励电源，所述延迟时间Δt_s满足：

令s＝s+1，令i＝i-1；if

Then the s-th level excitation power supply is triggered after a delay time Δt _s , and the delay time Δt _s satisfies:

Let s = s + 1, let i = i - 1;

则不准备触发任何激励电源，令i＝i-1；if

Then no excitation power supply is to be triggered, and i=i-1;

Step 4: When the armature passes through the center line of the first-stage drive coil and moves to the first photoelectric probe _Gz1 in front of the center line of the first-stage drive coil, the s-stage excitation power supply is triggered and turned on. This moment is _ts , and the distance between the armature and the center line of the first-stage drive coil is _xs = h/2; the armature speed measuring device performs measurement and the central controller performs signal processing to obtain the armature speed _vs at this position at time _ts ;

Step 5: cyclically execute the following steps 5-1, 5-2 and 5-3 until the time t _n at which the n-th stage excitation power supply is turned on is obtained:

Step 5-1: triggering and turning on the s+1th level excitation power supply at time ts ₊₁ , wherein the time _ts+1 satisfies:

v_s为时刻t_s电枢速度，a为电枢运动平均加速度，h为相邻两级驱动线圈中心间距，t_m为驱动线圈放电电流从零至达到最大值时的时间间隔；

v _s is the armature speed at time t _s , a is the average acceleration of the armature motion, h is the center distance between two adjacent drive coils, and t _m is the time interval when the discharge current of the drive coil changes from zero to the maximum value;

Step 5-2: The central controller calculates the estimated armature speed at time _ts+1 :

Step 5-3: Let s=s+1.

In combination with the first aspect, in certain implementations of the first aspect, the center line distance xs ₊₁ between the armature and the first-stage drive coil at time _ts+1 satisfies: _xs+1 = _xs +h- _atm ( _ts+1 - _ts )< _xs +h, where _xs is the center line distance between the armature and the first-stage drive coil at time _ts .

In combination with the first aspect, in certain implementations of the first aspect, the time and speed when the armature passes through the jth photoelectric probe _Gzj and the j+1th photoelectric probe Gzj ₊₁ in front of the center line of the first-stage drive coil are _tzj , _vzj and _tzj+1 , vzj ₊₁ respectively, and the time and speed when the armature passes through the j+1th photoelectric probe Gzj ₊₁ in front of the center line of the first-stage drive coil are

In conjunction with the first aspect, in certain implementations of the first aspect, the ballistic target satisfies at least one of the following:

The high-pressure gas gun tube and the electromagnetic launch tube are coaxial with each other and have the same inner diameter, which is not less than 50 mm;

The high-pressure gas gun tube is connected to the electromagnetic launch tube via a flange structure;

The high-pressure gas gun tube or electromagnetic launch tube is connected to each other in sections by pipes of the same specification, and each section is connected by a flange structure, a Huff nut structure or a Huff clamp structure;

The armature structure is an integral solid cylinder or a hollow cylinder;

The armature material is aluminum or aluminum alloy;

The model is a full-caliber model without a buttstock or a combined model with a buttstock. When the model is a full-caliber model without a buttstock, the model passes through an expansion box and enters the test chamber after being fired. When the model is a combined model with a buttstock, the combined model consists of a model body and a buttstock. After the model is fired, the buttstock and the model body are separated in the expansion box, and the model body enters the test chamber.

The expansion tank and the test chamber are equipped with a model velocity measurement system, a camera system for measuring the model position and posture, a shadow/schlieren instrument for flow field display, and a light radiation measurement system for measuring light radiation characteristics;

The ballistic target includes several supporting mechanisms and a track system, wherein the supporting mechanisms are respectively located under the high-pressure gas chamber, the high-pressure gas gun tube, the electromagnetic launch tube, the expansion tank and the test chamber, and the supporting mechanisms are installed on the track system and can move along the track;

The charger adopts an IGBT series resonant constant current charging power supply;

The test gas filled in the high-pressure gas gun barrel, electromagnetic launch tube, expansion box and test chamber in front of the model is air, and the air pressure is 10Pa～0.2MPa;

The velocity v za of the armature at the center line of the first-stage driving coil in the electromagnetic transmitting tube _satisfies 0＜v _za ≤150m/s.

In a second aspect, a timing trigger control method is provided, the method being applied to the ballistic target as described in any one of the implementations of the first aspect above, the method comprising:

Step 1: The high-pressure gas chamber releases gas to drive the armature to push the model forward;

Step 2: Let s = 1. When the armature moves past the mth photoelectric probe behind the center line of the first-stage drive coil, i = m. Circulate the following steps 2-1 and 2-2 until the first-stage excitation power supply is triggered:

Step 2-1: When the armature moves past the ith photoelectric probe behind the center line of the first-stage drive coil, the distance between the armature and the center line of the first-stage drive coil is l _fi1 =(i-1/2)h. The armature speed measuring device performs measurement and the central controller performs signal processing to obtain the armature speed v _fi at this moment and this position;

Step 2-2:

则在延迟时间Δt₁后触发第1级激励电源，所述延迟时间Δt₁满足：

令s＝s+1，令i＝i-1，跳转出本循环执行步骤3；if

Then the first stage excitation power supply is triggered after a delay time Δt ₁ , and the delay time Δt ₁ satisfies:

Let s=s+1, let i=i-1, jump out of this loop and execute step 3;

则不准备触发任何激励电源，令i＝i-1；if

Then no excitation power supply is to be triggered, and i=i-1;

Step 3: Circulate the following steps 3-1 and 3-2 until the armature passes the first photoelectric probe behind the center line of the first-stage drive coil and passes the center line of the first-stage drive coil;

Step 3-1: When the armature moves to the i-th photoelectric probe behind the center line of the first-stage drive coil, the distance between the armature and the center line of the s-th-stage drive coil is l _fis =(i+s-3/2)h. The armature speed measuring device performs measurement and the central controller performs signal processing to obtain the armature speed v _fi at this moment and this position;

Step 3-2:

则立即触发第s级激励电源，令s＝s+1，令i＝i-1；if

Then the s-th level excitation power supply is triggered immediately, let s = s + 1, let i = i - 1;

则在延迟时间Δt_s后触发第s级激励电源，所述延迟时间Δt_s满足：

令s＝s+1，令i＝i-1；if

Then the s-th level excitation power supply is triggered after a delay time Δt _s , and the delay time Δt _s satisfies:

Let s = s + 1, let i = i - 1;

则不准备触发任何激励电源，令i＝i-1；if

Then no excitation power supply is to be triggered, and i=i-1;

Step 4: When the armature passes through the center line of the first-stage drive coil and moves to the first photoelectric probe _Gz1 in front of the center line of the first-stage drive coil, the s-stage excitation power supply is triggered and turned on. This moment is _ts , and the distance between the armature and the center line of the first-stage drive coil is _xs = h/2; the armature speed measuring device performs measurement and the central controller performs signal processing to obtain the armature speed _vs at this position at time _ts ;

Step 5: cyclically execute the following steps 5-1, 5-2 and 5-3 until the time t _n at which the n-th stage excitation power supply is turned on is obtained:

Step 5-1: triggering and turning on the s+1th level excitation power supply at time ts ₊₁ , wherein the time _ts+1 satisfies:

v_s为时刻t_s电枢速度，a为电枢运动平均加速度，h为相邻两级驱动线圈中心间距，t_m为驱动线圈放电电流从零至达到最大值时的时间间隔；

v _s is the armature speed at time t _s , a is the average acceleration of the armature motion, h is the center distance between two adjacent drive coils, and t _m is the time interval when the discharge current of the drive coil changes from zero to the maximum value;

Step 5-2: The central controller calculates the estimated armature speed at time _ts+1 :

Step 5-3: Let s=s+1.

Compared with the prior art, the solution provided by this application includes at least the following beneficial technical effects:

(1) The launcher of the present invention adopts a composite drive mode of high-pressure gas and electromagnetic ejection. Compared with a single-stage cannon driven by high-pressure gas, the launcher's driving capacity is increased by several times. The multi-stage energy-enabling characteristics of the electromagnetic drive device can be utilized to solve the high energy supply problem required by large-caliber equipment by increasing the number of excitation power supplies and drive coil stages.

(2) The launch device of the present invention adopts a composite drive mode of high-pressure gas and electromagnetic ejection. An insulating launch tube is arranged between the driving coil (primary) and the armature (secondary) of the electromagnetic ejection device. Relevant studies have shown that the larger the caliber, the higher the electromagnetic coupling efficiency and electromagnetic energy conversion efficiency. When the caliber is below 50 mm, the coupling efficiency and electromagnetic energy conversion efficiency will drop sharply. The launch tube caliber of the present invention is set to be at least greater than or equal to 50 mm. Compared with the electromagnetically driven two-stage gun, the launch tube caliber is increased several times while ensuring a higher energy conversion efficiency, which is particularly suitable for large-size and large-mass model ballistic target testing.

(3) High-pressure gas drive alone or multi-stage electromagnetic drive alone has its own unique internal ballistic characteristics. When high-pressure gas drive alone is used, the initial acceleration of the projectile is fast, but the pressure at the bottom of the projectile decreases rapidly, and it is impossible to provide a high average pressure for the projectile, resulting in poor internal ballistic performance and weak follow-up. When electromagnetic ejection drive alone is used, the armature needs to accelerate from a standstill and accelerates slower than the initial acceleration of high-pressure gas drive. The present invention adopts a composite drive method based on high-pressure gas first and electromagnetic ejection later, combining the advantages of their respective driving characteristics, first driving the armature with high-pressure gas to accelerate quickly, giving the armature a certain initial velocity when electromagnetic launch is started, and then utilizing the electromagnetic ejection device's excitation power supply and drive coil axial distribution, multi-stage empowerment, and single-stage independent regulation and control characteristics. By regulating the circuit structure parameters and electromagnetic parameters at each level, the energy storage and empowerment schemes are optimized, ensuring a high energy conversion efficiency while making the speed and acceleration of the model motion process more stable and controllable, improving the internal ballistic characteristics overall, and achieving "soft launch".

(4) The launch device of the present invention adopts a composite drive mode of high-pressure gas and electromagnetic catapult, which has higher structural sealing and safety, and is a safer, cleaner and more efficient power source than gunpowder or hydrogen-oxygen explosion.

(5) 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 the electromagnetic driving force as an independent power source for ballistic targets will have more and more advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a ballistic target structure of a first-stage gas cannon driven by electromagnetic ejection assistance;

FIG2 is a schematic diagram of an electromagnetic ejection device and a timing trigger control system;

FIG3 is a schematic diagram showing the arrangement and timing trigger control method of the armature speed measuring device;

FIG4 is a schematic diagram of the structure of a high-pressure air chamber section;

FIG5 is a schematic diagram of the Hough nut connection structure between the sections of the high-pressure gas gun tube;

FIG6 is a schematic diagram of the connection structure between the high-pressure gas chamber and the high-pressure gas gun barrel flange;

FIG7 is a schematic diagram of the flange connection structure between the high-pressure gas gun tube and the electromagnetic launch tube;

FIG8 is a schematic diagram of the flange connection structure between the electromagnetic transmitting tube segments;

Figure 9 is a top view of the expansion tank, test chamber and related measurement and control equipment.

Description of Figure Numbers:

1-high-pressure gas propulsion section; 101-high-pressure gas chamber; 10101-high-pressure gas chamber cavity; 10102-exhaust cavity; 10103-compensation hole; 10104-buffer cavity; 10105-check valve; 10106-damping cavity; 10107-spring; 10108-valve body; 10109-intake valve; 10110-exhaust valve; 102-connecting mechanism A; 10201-steel flange pipe fitting Aa; 10202-steel flange pipe fitting Ab; 10203-steel bolt assembly Ac; 103-high-pressure gas barrel; 10301-high pressure Section k of gas gun barrel; 10302-section k+1 of high pressure gas gun barrel; 10303-Huff nut assembly; 2-armature; 3-model; 4-connecting mechanism B; 401-steel flange pipe fitting Ba; 402-insulating flange pipe fitting Bb; 403-bolt assembly Bc; 5-electromagnetic ejection device; 501-electromagnetic launch tube; 50101-section k of electromagnetic launch tube; 50102-section k+1 of electromagnetic launch tube; 502-driving coil; 503-metal layer; 504-charger; 50401-charging switch; 505-excitation power supply; 505 01-energy storage pulse capacitor bank; 50502-main switch; 50503-freewheeling switch; 506-insulating flange connection mechanism C; 50601-insulating flange pipe fitting Ca; 50602-insulating flange pipe fitting Cb; 50603-insulating bolt assembly Cc; 6-expansion tank; 601-expansion tank and vacuum system interface; 602-expansion tank side observation window; 603-expansion tank top observation window; 7-test cabin; 701-test cabin and vacuum system interface; 702-test cabin side observation window; 703-test cabin top observation window; 8-measurement and control system; 801-central controller; 802-pulse trigger circuit; 803-armature speed measuring device in the transmitting tube; 80301-photoelectric sensor body; 80302-photoelectric probe; 804-excitation power supply voltage measuring device; 805-driving coil current measuring device; 806-model speed measuring device in the expansion box; 807-binocular vision measurement system of the expansion box; 808-model speed measuring device in the test cabin; 809-test cabin schlieren; 810-test cabin binocular vision measurement system; 811-test cabin light radiation measuring instrument; 9-support mechanism; 10-track system.

DETAILED DESCRIPTION

The present invention will be described more clearly and completely below in conjunction with the accompanying drawings. A person skilled in the art will be able to implement the present invention based on these descriptions.

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

As shown in FIGS. 1 and 2 , a ballistic target based on an electromagnetic ejection-assisted driven first-stage gas cannon includes a high-pressure gas propulsion section 1, an armature 2, a model 3, an electromagnetic ejection device 5, an expansion tank 6, a test chamber 7 and a measurement and control system 8.

The high-pressure gas propulsion section 1 includes a high-pressure gas chamber 101 and a high-pressure gas gun barrel 103. The electromagnetic ejection device 5 includes an electromagnetic launch tube 501 and a multi-stage drive coil 502 wound on the electromagnetic launch tube 501. The high-pressure gas chamber 101, the high-pressure gas gun barrel 103, the electromagnetic launch tube 501, the expansion tank 6 and the test chamber 7 are connected in sequence. The electromagnetic ejection device 5 may also include an excitation power supply 505 for supplying power to the multi-stage drive coil 502 and a charger 504 for charging the excitation power supply. The charger 504 may use an IGBT series resonant constant current charging power supply.

The high-pressure gas gun barrel 103 is equipped with an armature 2 and a model 3, and the armature 2 is behind the model 3. The high-pressure gas chamber 101 is filled with high-pressure gas. The high-pressure gas gun barrel 103 in front of the model 3, the electromagnetic launch tube 501, the expansion tank 6 and the test chamber 7 are filled with test gas. In a preferred embodiment, the high-pressure gas in the high-pressure gas chamber 101 is high-pressure air or high-pressure nitrogen or high-pressure helium, and the gas pressure is not greater than 30MPa; the test gas filled in the high-pressure gas gun barrel 103 in front of the model 3, the electromagnetic launch tube 501, the expansion tank 6 and the test chamber 7 is air, and the air pressure is 10Pa~0.2MPa.

The high-pressure gas chamber 101 releases high-pressure gas, driving the armature 2 and the model 3 to move forward and fly out of the high-pressure gas gun tube 103. In the electromagnetic launch tube 501, the armature 2 pushes the model 3 to be launched at high speed under the combined drive of the high-pressure gas thrust and the electromagnetic force. The model 3 passes through the expansion tank 6 and enters the test chamber 7.

In one embodiment, after the gas in the high-pressure chamber is released, it drives the armature and the piston to move in an isentropic expansion mode. The total pressure P _1x and the total temperature T _1x of the gas in the high-pressure chamber are expressed as follows:

Wherein, γ ₁ is the specific heat ratio of high-pressure gas, P ₁₀ is the initial pressure of high-pressure gas, T ₁₀ is the initial temperature of high-pressure gas, V ₁₀ is the initial volume of high-pressure gas, x is the distance moved by armature 2, D is the inner diameter of electromagnetic transmitting tube 501, and V _1x (x) is the volume of high-pressure gas when armature 2 moves x distance.

In one embodiment, the high-pressure gas chamber 101 includes a release mechanism, which is a piston-type release mechanism or a double-diaphragm release mechanism, which plays the role of isolating gas and opening quickly.

In one embodiment, the high pressure gas gun barrel 103 is made of metal material, preferably gun steel material.

The electromagnetic transmitting tube 501 plays a guiding role. In one embodiment, the electromagnetic transmitting tube 501 is made of insulating material to ensure that the driving coil 502 and the armature 2 are not electrically conductive, and to ensure good electromagnetic induction between the driving coil 502 and the armature 2. The maximum operating temperature of the electromagnetic transmitting tube 501 can reach 260 degrees Celsius, so that the temperature rise caused by the acceleration of the armature 2 is within the operating temperature range of the electromagnetic transmitting tube 501. The electromagnetic transmitting tube 501 is preferably made of high-strength resin-based composite materials or high-strength ceramic materials.

In one embodiment, the conductor of the electromagnetic ejection device driving coil 502 is made of copper material, and the outside of the driving coil 502 conductor is covered with insulating material. The electromagnetic ejection device 5 may also include a metal layer 503, which may be covered on the outside of the multi-stage driving coil 502. The metal layer 503 plays an electromagnetic shielding role and plays a structural strengthening role for the electromagnetic launch tube 501 and the multi-stage driving coil 502.

In one embodiment, 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.

In one embodiment, model 3 is a full-caliber model without a buttstock or a combination model with a buttstock; when model 3 is a full-caliber model without a buttstock, model 3 passes through an expansion box and enters a test chamber after being fired; when model 3 is a combination model with a buttstock, the combination model consists of a model body and a buttstock, and after model 3 is fired, the buttstock and the model body are separated in the expansion box, and the model body enters the test chamber.

In one embodiment, the number of multi-stage drive coils of the electromagnetic ejection device 1 is n, where n≥3. Under the conditions of the set model peak velocity, average acceleration, pump tube diameter and other basic parameters, the acceleration length, electric energy-kinetic energy conversion efficiency and expected total energy are reasonably estimated, and combined with the single-stage drive coil and the excitation power supply limit parameter conditions (voltage resistance, current resistance, stress, temperature rise, equipment cost, etc.), the reasonable number of drive coils 502 is determined after comprehensive consideration, so as to achieve efficient and safe acceleration of the armature 2 and the model 3. If the number of drive coils 502 is too small, the single-stage energy is too large, which affects the safety, technical difficulty and cost of the drive coils 502 and the excitation power supply 505; if the number of drive coils 502 is too large, the single-stage energy 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 greatly increases the equipment footprint and equipment cost.

In one embodiment, the ratio of the length of each stage of the driving coil 502 of the electromagnetic catapult device 1 to the inner diameter of the electromagnetic launch tube 501 is 0.4 to 1.7, and the ratio of the distance between the end faces of the adjacent stages of the driving coil 502 to the inner diameter of the electromagnetic launch tube 501 is 0.1 to 0.3. By properly setting the length of the driving coil 502, it is beneficial to make the mutual inductance gradient and the overall driving capacity of the driving coil 502 and the armature 2 within a reasonable range.

In one embodiment, as shown in FIG2 , each stage of the driving coil 502 of the electromagnetic ejection device is respectively connected to an independent excitation power supply 505, and the excitation power supply 505 includes an energy storage pulse capacitor group 50501, a main switch 50502, and a freewheeling switch 50503. The energy storage pulse capacitor group 50501 can be connected in series with the main switch 50502, and connected in parallel with the freewheeling switch 50503 at both ends of the driving coil 502. Both ends of the energy storage pulse capacitor group 50501 are also connected to both ends of the charger 504 through a charging switch 50401.

The charger 504 is connected to the energy storage pulse capacitor group 50501 through the charging switch 50401; before the excitation power supply 505 works, the charging switch 50401 is turned on, and the charger 504 charges the energy storage pulse capacitor group 50501. When the energy storage pulse capacitor group 50501 is charged to a predetermined voltage, the charging switch 50401 is turned off, and the charger 504 stops charging.

The excitation power source 505 is discharged step by step by using a timing trigger control method through the measurement and control system 8. The measurement and control system 8 monitors the voltage information of the excitation power source 505, the current information of the driving coil 502, the pressure and temperature information of the high-pressure gas and the test gas, the motion information of the high-pressure gas barrel 103, the electromagnetic launch tube 501, the armature 2 and the model 3 in the expansion tank 6, and the motion information, aerodynamic/thermal information, aerodynamic physical information or high-speed collision information of the model 3 in the test chamber 7 through sensors.

The measurement and control system 8 includes a central controller 801, a pulse trigger circuit 802, and an armature speed measuring device 803. The central controller 801 is preferably a digital signal processor DSP or a field programmable logic gate array FPGA. The armature speed measuring device 803 includes a photoelectric sensor body 80301 and a photoelectric probe 80302. A plurality of photoelectric probes 80302 of the armature speed measuring device 803 are installed on the wall of the high-pressure gas gun tube 103 and the electromagnetic transmitting tube 501 at intervals along the armature movement direction; the photoelectric sensor body 80301 and the photoelectric probe 80302 are connected through optical fibers. The photoelectric probe 80302 of the armature speed measuring device 803 can send a pulse light signal of a certain frequency to the armature 2 through the through holes on the wall of the high-pressure gas gun tube 103 and the electromagnetic transmitting tube 501 and receive the light signal reflected from the self-reflective light ring, and convert the light signal into an electrical signal and transmit it to the central controller 801.

The central controller 801 processes the electrical signal to obtain the moment and speed of the armature 2 (specifically, the area where the armature 2 is located at or close to the rear end face, and the rear refers to the direction in which the armature 2 is away from the model 3) passing through the photoelectric probe 80302, and calculates the expected triggering moment of the to-be-triggered stage through the timing trigger control method, or queries the pre-stored data table to obtain the expected triggering moment of the to-be-triggered stage. At the expected triggering moment, the central controller sends a trigger control signal to the pulse trigger circuit 802, and the pulse trigger circuit 802 outputs a power pulse to turn on the main switch 50502 of the next-level excitation power supply, so that the energy storage pulse capacitor group 50501 discharges through the drive coil 502. When the voltage of the energy storage pulse capacitor group 50501 drops to zero, the freewheeling switch 50503 is turned on, the main switch 50502 is turned off, and the drive coil 502 continues to flow through the freewheeling switch 50503 until the discharge current drops to zero. Each level of excitation power supply works step by step in this way.

v_za为电枢2(具体是电枢2位于或接近后端面的区域)在电磁发射管501内第1级驱动线圈中心线处速度，h为相邻驱动线圈中心线轴向间距，t_m为驱动线圈放电电流从零上升至最大值时的时间间隔。在一些实施例中，v_za满足0＜v_za≤1500m/s。优选

在一些实施例中，t_m可以根据

确定，L_d为驱动线圈放电电流经二级管续流之前的放电回路所有自感之和，C为储能电容器组电容值。As shown in Fig. 3, at least m photoelectric probes _Gf1 , _Gf2 , ..., Gfi _-1 , _Gfi , ..., _Gfm-1 , _Gfm are evenly arranged axially backward from the center line of the first-stage driving coil. The axial spacing between the first photoelectric probe _Gf1 and the center line of the first-stage driving coil is h/2, and the axial spacing between adjacent photoelectric probes is h.

_vza is the velocity of the armature 2 (specifically, the area where the armature 2 is located at or near the rear end face) at the center line of the first stage drive coil in the electromagnetic transmitting tube 501, h is the axial spacing between the center lines of adjacent drive coils, and _tm is the time interval when the discharge current of the drive coil rises from zero to the maximum value. In some embodiments, _vza satisfies 0 _＜ vza≤1500m/s.

In some embodiments, _tm can be calculated based on

It is determined that _Ld is the sum of all self-inductances of the discharge circuit before the discharge current of the driving coil is freewheeling through the diode, and C is the capacitance value of the energy storage capacitor group.

At least n photoelectric probes _Gz1 , _Gz2 , ..., _Gzj , Gzj ₊₁ , ..., _Gzn-1 , _Gzn are evenly arranged axially forward from the center line of the first-stage driving coil. The first photoelectric probe _Gz1 is located on the tube wall between the first-stage driving coil and the second-stage driving coil. The distance between the first photoelectric probe _Gz1 and the center line of the first-stage driving coil is equal to the distance between the first photoelectric probe _Gz1 and the center line of the second-stage driving coil. The axial intervals between adjacent photoelectric probes are h.

The timing trigger control method executed by the central controller may be specifically as follows.

Step 1: Before the test, the armature 2 and the model 3 are pre-placed in the rear end of the high-pressure gas gun tube 103 and at an appropriate position near the outlet of the high-pressure gas chamber 101. First, the exhaust valve 10110 of the high-pressure gas chamber 101 is opened, and at the same time, the armature speed measuring device 803 is controlled to emit a light signal into the tube at an appropriate frequency. The high-pressure gas chamber 101 releases high-pressure gas to drive the armature 2, and the armature 2 pushes the model 3 to move forward in the high-pressure gas gun tube 103, and the speed of the armature 2 and the model 3 increases continuously.

Step 2: Waiting to trigger the first stage excitation power supply, s = 1, when the armature 2 moves past the mth photoelectric probe behind the center line of the first stage drive coil, i = m. Execute the following steps 2-1 and 2-2 repeatedly until the first stage excitation power supply is triggered:

Step 2-1: When the armature 2 moves past the i-th photoelectric probe behind the center line of the first-stage drive coil, the distance between the armature 2 and the center line of the first-stage drive coil is l _fi1 =(i-1/2)h. The armature speed measuring device 803 performs measurement and the central controller 801 performs signal processing to obtain the speed v _fi of the armature 2 at this moment and this position;

Step 2-2:

则在延迟时间Δt₁后触发第1级激励电源，延迟时间Δt₁满足：

令s＝s+1，令i＝i-1，跳转出本循环执行步骤3；if

Then the first stage excitation power supply is triggered after the delay time Δt ₁ , and the delay time Δt ₁ satisfies:

Let s=s+1, let i=i-1, jump out of this loop and execute step 3;

则不准备触发任何激励电源，令i＝i-1；if

Then no excitation power supply is to be triggered, and i=i-1;

When i=1, the loop is jumped out, s=s+1 is set, and step 3 is executed.

Step 3: Execute the following steps 3-1 and 3-2 repeatedly until the armature 2 passes the first photoelectric probe behind the center line of the first-stage driving coil and passes the center line of the first-stage driving coil.

Step 3-1: When the armature 2 moves to the i-th photoelectric probe behind the center line of the first-stage driving coil, the distance between the armature 2 and the center line of the s-th-stage driving coil is l _fis =(i+s-3/2)h. The armature speed measuring device 803 performs measurement and the central controller 801 performs signal processing to obtain the speed v _fi of the armature 2 at this moment and this position.

Step 3-2:

则立即触发第s级激励电源，令s＝s+1，令i＝i-1；if

Then the s-th level excitation power supply is triggered immediately, let s = s + 1, let i = i - 1;

则在延迟时间Δt_s后触发第s级激励电源，延迟时间Δt_s满足：

令s＝s+1，令i＝i-1；if

Then the s-th level excitation power supply is triggered after the delay time Δt _s , and the delay time Δt _s satisfies:

Let s = s + 1, let i = i - 1;

则不准备触发任何激励电源，令i＝i-1。if

Then no excitation power supply is to be triggered, and i=i-1.

Step 4: When the armature 2 passes through the center line of the first-stage driving coil and moves to the first photoelectric probe _Gz1 in front of the center line of the first-stage driving coil, the s-th stage excitation power supply is triggered to be turned on. This moment is _ts . The distance between the armature 2 and the center line of the first-stage driving coil is _xs =h/2. The armature speed measuring device 803 performs measurement and the central controller 801 performs signal processing to obtain the speed _vs of the armature 2 at this position at time _ts .

Step 5: cyclically execute the following steps 5-1, 5-2 and 5-3 until the time t _n at which the n-th stage excitation power supply is turned on is obtained:

Step 5-1: At time _ts+1, the s+1th level excitation power supply is triggered to turn on. At time _ts+1, the following conditions are satisfied:

v_s为时刻t_s电枢2速度，a为电枢2运动平均加速度，h为相邻两级驱动线圈中心间距，t_m为驱动线圈放电电流从零至达到最大值时的时间间隔；

v _s is the speed of armature 2 at time t _s , a is the average acceleration of armature 2, h is the center distance between two adjacent driving coils, and t _m is the time interval from zero to the maximum value of the discharge current of the driving coil;

Step 5-2: The central controller calculates the estimated speed of armature 2 at time _ts+1 :

将此预计速度作为时刻t_s+1时电枢2实际速度的近似值，同时通过中央控制器可以计算得到时刻t_s+1时电枢2与第1级驱动线圈中心线间距的近似值为x_s+1＝x_s+h-at_m(t_s+1-t_s)＜x_s+h；

This estimated speed is used as the approximate value of the actual speed of the armature 2 at time _ts+1 . At the same time, the central controller can calculate the approximate value of the distance between the armature 2 and the center line of the first-stage driving coil at time _ts+1 as xs ₊₁ = _xs +h- _atm ( _ts+1 - _ts ) < _xs +h;

Step 5-3: Let s=s+1.

In some scenarios, the time and speed when the armature 2 passes the jth photoelectric probe _Gzj and the j+1th photoelectric probe _Gzj+1 in front of the center line of the first-stage driving coil are _tzj , _vzj and _tzj+1 , vzj ₊₁ respectively, where the time and speed when the armature 2 passes the first photoelectric probe _Gz1 in front of the center line of the first-stage driving coil are _tz1 = _ts , _vz1 = _vs respectively; the time and speed estimated values when the armature 2 passes the j+1th photoelectric probe Gzj ₊ in front of the center line of the first-stage driving coil can be calculated by the central controller:

The photoelectric probes _Gz2 , ..., _Gzj , Gzj ₊₁ , ..., _Gzn-1 , _Gzn can be used to measure the time and speed when the armature 2 passes through the corresponding position, and compare them with the estimated time and speed calculated by the central controller 801, so as to facilitate the monitoring and analysis of the motion state of the armature 2 and the timing trigger control effect, but may not participate in the dynamic control of the timing trigger.

Furthermore, the energy storage pulse capacitor group 50501 is composed of metallized film self-healing pulse capacitors, the energy volume ratio of the metallized film self-healing pulse capacitor is greater than or equal to 0.5MJ/m ³ , and the working life is greater than or equal to 1000 times.

Furthermore, the main switch 50502 is a spark gap switch or a semiconductor high-voltage switch composed of a thyristor.

Furthermore, the freewheeling switch 50503 is composed of a combination of semiconductor high-voltage diodes.

As shown in FIG2 , the measurement and control system 8 may further include an excitation power supply voltage measuring device 804 and a drive coil current measuring device 805. The excitation power supply voltage measuring device 804 may be used to monitor the voltage of the energy storage pulse capacitor bank 50501. The drive coil current measuring device 805 may be used to monitor the current of the drive coil 502.

High-pressure gas propulsion section 1 embodiment:

As shown in FIG4 , the high-pressure gas chamber 101 is connected to the high-pressure gas gun barrel 103 through the connecting mechanism A102. The high-pressure gas chamber 101 includes a piston-type release mechanism, the principle of which is: the high-pressure gas enters the exhaust chamber 10102 from the intake valve 10109, and the pressure in the exhaust chamber 10102 continues to rise, so that the valve body piston moves to the right to compress the spring 10107 and finally presses the valve body against the entrance of the high-pressure gas chamber 101. At the same time, the one-way valve 10105 is opened, and the high-pressure gas enters the inner chamber 10101 of the high-pressure gas chamber from the exhaust chamber 10102, and the intake valve 10109 is closed after reaching a predetermined pressure. When release is required, the exhaust valve 10110 is opened, and the high-pressure gas in the exhaust chamber 10102 is quickly discharged, and the gas enters the damping chamber 10106 through the compensation hole 10103. Due to the huge pressure difference between the left and right ends of the valve body piston and the elastic force of the spring 10107, the valve body 10108 moves rapidly to the left, and the valve body 10108 leaves the entrance of the high-pressure gas chamber 101. The high-pressure gas in the inner cavity 10101 of the high-pressure gas chamber immediately enters the high-pressure gas barrel 103, driving the armature 2 to push the model 3 to move forward in the high-pressure gas barrel 103. When the left end of the valve body enters the buffer chamber 10104, the gas in the buffer chamber 10104 is compressed, which prevents the valve body 10108 from directly colliding with the release mechanism.

Due to the limitation of manufacturing process, the length of pipes of the same specification is usually limited. When the high-pressure gas gun tube 103 or the electromagnetic launch tube 501 needs to be connected to each other in sections by pipes of the same specification, the sections are connected by flange structure, Huff nut structure or Huff clamp structure.

An embodiment of the connection mechanism between the sections of the high-pressure gas gun tube 103:

As shown in FIG5 , the kth section 10301 of the high-pressure gas gun barrel is adjacent to the k+1th section of the high-pressure gas gun barrel. The right end of the kth section 10301 of the high-pressure gas gun barrel is provided with a concave stop, and the left end of the k+1th section 10302 of the high-pressure gas gun barrel is provided with a convex stop. The two are connected and fastened by a steel half nut assembly 10303 .

In one embodiment, the high-pressure gas chamber 101 is connected to the high-pressure gas gun tube 103 via a connecting mechanism A102; the connecting mechanism A102 is a flange structure or an open serrated thread structure.

The flange connection embodiment of the high pressure gas chamber 101 and the high pressure gas gun tube 103:

As shown in FIG6 , the inlet straight pipe section of the high-pressure gas chamber 101 is connected to the left end of the high-pressure gas gun barrel 103 through a connecting mechanism A102. The inlet straight pipe section of the high-pressure gas chamber 101 has a concave stopper, and the left end of the high-pressure gas gun barrel 103 has a convex stopper. The connecting mechanism A102 includes a steel flange pipe fitting Aa10201, a steel flange pipe fitting Ab10202, and a steel bolt assembly Ac10203. The steel flange pipe fitting Aa10201 and the steel flange pipe fitting Ab10202 are respectively fixed to the outer surface of the inlet straight pipe section of the high-pressure gas chamber 101 and the outer surface of the left end of the high-pressure gas gun barrel 103 by threads or welding, and the steel flange pipe fitting Aa10201 and the steel flange pipe fitting Ab10202 are connected and fastened by the steel bolt assembly Ac10203.

In one embodiment, the ratio of the volume of the high-pressure gas gun tube 103 to the volume of the high-pressure gas chamber 101 is ≥1.0.

In one embodiment, the high-pressure gas gun tube 103 is connected to the electromagnetic launch tube 501 via a connecting mechanism B4, and the connecting mechanism B4 is a flange structure.

Embodiment B4 of the connection mechanism between the high-pressure gas gun tube 103 and the electromagnetic launch tube 501:

As shown in Figure 7, the high-pressure gas gun barrel 103 has the same inner diameter as the electromagnetic launch tube 501. Usually, the wall thickness of the high-pressure gas gun barrel 103 is larger, and the wall thickness of the electromagnetic launch tube 501 is smaller. The high-pressure gas gun barrel 103 is connected to the electromagnetic launch tube 501 through a connecting mechanism B4. The connecting mechanism B4 includes a steel flange pipe Ba401, an insulating flange pipe Bb402 and a bolt assembly Bc403. The steel flange pipe Ba401 is fixed to the outer surface of the right end of the high-pressure gas gun barrel 103 by thread or welding, and the insulating flange pipe Bb is fixed to the outer surface of the left end of the electromagnetic launch tube 501 by bonding. The steel flange pipe Ba401 and the insulating flange pipe Bb are connected and tightened by the bolt assembly Bc403.

In one embodiment, the high-pressure gas gun tube 103 and the electromagnetic launch tube 501 are coaxial with each other and have the same inner diameter, which is not less than 50 mm.

Embodiment of the connection mechanism between the sections of the electromagnetic transmitting tube 501:

As shown in Fig. 8, the electromagnetic transmitting tube k section 50101 and the electromagnetic transmitting tube k+1 section 50102 are adjacent and connected by an insulating flange connection mechanism C506. The insulating flange pipe fitting Ca50601 with a concave stop and the insulating flange pipe fitting Cb50602 with a convex stop are respectively bonded and fixed to the outer surface of the left end of the electromagnetic transmitting tube k section 50601 and the outer surface of the right end of the electromagnetic transmitting tube k+1 section, and the two are connected and fastened by an insulating bolt assembly Cc50603.

Expansion tank, test chamber and related measurement and control device embodiments:

As shown in Fig. 9, the expansion tank 6 and the test chamber 7 are filled with air with a pressure range of 10Pa to 0.2MPa. The expansion tank 6 is provided with a vacuum system interface 601, a plurality of side optical windows 602 and a top optical window 603, a plurality of expansion tank internal model velocity measuring devices 806 are installed on the side, and a plurality of expansion tank binocular vision measurement systems 807 for measuring the dynamic process of separation of the combined model support and the model body are installed on the side and top; the test chamber 7 is provided with a vacuum system interface 701, a plurality of side optical windows 702 and a top optical window 703, a plurality of test chamber internal model velocity measuring devices 808, a flow field display schlieren 809 and an optical radiation measurement system 711 for measuring optical radiation characteristics are installed on the side, and a binocular vision measurement system 710 for measuring the model flight attitude is installed on the side and top.

In one embodiment, the expansion tank 6 and the test chamber 7 are equipped with a model velocity measurement system, a camera system for measuring the model position and posture, a shadow/schlieren instrument for flow field display, and a light radiation measurement system for measuring light radiation characteristics.

In one embodiment, the ballistic target includes several supporting mechanisms 9 and a track system 10. The supporting mechanisms 9 are respectively located below the high-pressure gas chamber 101, the high-pressure gas gun barrel 103, the electromagnetic launch tube 501, the expansion tank 5 and the test chamber 7. The supporting mechanisms 9 are installed on the track system 10 and can move along the track.

The working principle of the present invention is as follows:

触发导通第s+1级激励电源，循环执行时序触发控制方法相关步骤，直到导通第n级激励电源。在匀加速运动过程中，电枢2在气体推力和已导通放电的若干级驱动线圈电磁力复合作用下推动模型向前运动。电枢2在电磁力及后端面气体推力、前端面轻质气体阻力的复合作用下推动模型3高速飞出电磁发射管501。模型3为不带弹托的全口径模型时，发射后经过膨胀箱6进入试验舱7；模型3为带弹托的组合体模型时，弹托和模型本体在膨胀箱6内实现分离，模型本体进入试验舱7。Before the test, the armature 2 is placed in an appropriate position (such as: inside the rear end of the high-pressure gas barrel, near the outlet of the high-pressure gas chamber). During the test, the exhaust valve 10110 of the high-pressure gas chamber 101 is first opened, and the armature speed measuring device 803 is controlled to emit a light signal into the high-pressure gas barrel 103 at an appropriate frequency. The high-pressure gas chamber 101 releases high-pressure gas to drive the armature 2 to push the model 3 forward in the high-pressure gas barrel 103, and the speed of the armature 2 and the model 3 increases continuously. When the armature 2 moves through the mth photoelectric probe behind the center line of the first-stage drive coil, the armature 2 has a certain initial velocity. The armature speed measuring device 803 performs measurement, the central controller 801 performs signal processing, and the relevant steps of the timing trigger control method are cyclically executed to solve the first-stage estimated trigger time. At the expected triggering moment, the central controller 801 sends a trigger control signal to the pulse trigger circuit 802, and the pulse trigger circuit 802 outputs a power pulse to turn on the first-stage excitation power main switch 50502, so that the first-stage energy storage pulse capacitor group 50501 discharges through the first-stage drive coil 502. After the voltage of the energy storage pulse capacitor group 50501 drops to zero, the drive coil 502 continues to flow through the freewheeling switch 50503, and the pulse current excites the pulse magnetic field to cause the armature 2 to generate eddy current and be acted upon by electromagnetic force. After the first stage is triggered, the armature 2 pushes the model forward under the combined action of the gas thrust and the electromagnetic force of the first-stage drive coil. Continue to execute the relevant steps of the timing trigger control method, and after triggering several stages of excitation power, the armature 2 moves under the combined action of the gas thrust and the electromagnetic force of several stages of the drive coils that have been turned on and discharged, passes through the first photoelectric probe behind the center line of the first-stage drive coil, and passes through the center line of the first-stage drive coil. At time _ts , armature 2 moves to the first photoelectric probe in front of the center line of the first-stage drive coil, triggering the s-stage excitation power supply to be turned on, and the speed of armature 2 at this moment is measured to obtain the speed _vs. After time _ts , armature 2 basically moves at a roughly constant acceleration.

The s+1th level excitation power supply is triggered and the steps related to the timing trigger control method are executed cyclically until the nth level excitation power supply is turned on. During the uniform acceleration motion, the armature 2 pushes the model forward under the combined action of the gas thrust and the electromagnetic force of the several levels of driving coils that have been turned on and discharged. The armature 2 pushes the model 3 to fly out of the electromagnetic launch tube 501 at high speed under the combined action of the electromagnetic force, the gas thrust of the rear end face, and the light gas resistance of the front end face. When the model 3 is a full-caliber model without a buttstock, it passes through the expansion box 6 and enters the test chamber 7 after launch; when the model 3 is a combined model with a buttstock, the buttstock and the model body are separated in the expansion box 6, and the model body enters the test chamber 7.

The present invention has been described in detail above in conjunction with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements can be made to the technical solution of the present invention and its implementation methods, which all fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims. The contents not described in detail in the specification of the present invention belong to the common technology of those skilled in the art. The present invention is further described below by taking the implementation methods of the accompanying drawings as an example. The following examples are only descriptive, not restrictive, and the scope of protection of the present invention cannot be limited by them.

Claims (15)

1. A ballistic target based on electromagnetic ejection auxiliary drive of a first-stage gas cannon, characterized in that it is used to perform flight measurement of a model (3), the ballistic target comprising a high-pressure gas propulsion section (1), an armature (2), a model (3), an electromagnetic ejection device (5), an expansion tank (6), a test chamber (7) and a measurement and control system (8); wherein, The high-pressure gas propulsion section (1) comprises a high-pressure gas chamber (101) and a high-pressure gas gun tube (103); the high-pressure gas gun tube (103) is equipped with the armature (2) and the model (3); the armature (2) is located behind the model (3); The electromagnetic ejection device (5) comprises an electromagnetic launch tube (501), a multi-stage drive coil (502) wound on the electromagnetic launch tube (501), an excitation power supply (505) for supplying power to the multi-stage drive coil (502), and a charger (504) for charging the excitation power supply (505); the high-pressure gas chamber (101), the high-pressure gas gun tube (103), the electromagnetic launch tube (501), the expansion tank (6), and the test chamber (7) are connected in sequence; The high-pressure gas chamber (101) releases gas to drive the armature (2) and the model (3) to move forward and fly out of the high-pressure gas gun tube (103); in the electromagnetic launch tube (501), the armature (2) pushes the model (3) under the combined drive of gas thrust and electromagnetic force; the model (3) flies out of the electromagnetic launch tube (501) and passes through the expansion box (6) into the test chamber (7); The measurement and control system (8) is used to determine the triggering moment of each level of excitation power supply (505) according to the moving speed and position of the armature (2). 2. The ballistic target according to claim 1, characterized in that the high-pressure gas propulsion section (1) satisfies at least one of the following: The gas in the high-pressure gas chamber (101) is air, nitrogen or helium, and the gas pressure is not greater than 30 MPa; The high-pressure gas chamber (101) is connected to the high-pressure gas gun tube (103) via a flange structure or an open sawtooth thread structure; After the gas in the high-pressure gas chamber (101) is released, the total pressure P _1x and the total temperature T _1x of the gas in the high-pressure gas chamber (101) are expressed as follows:

Wherein, γ ₁ is the specific heat ratio of the gas, P ₁₀ is the initial pressure of the gas, T ₁₀ is the initial temperature of the gas, V ₁₀ is the initial volume of the gas, x is the distance moved by the armature (2), D is the inner diameter of the electromagnetic transmitting tube (501), and V _1x (x) is the volume of the gas when the armature (2) moves a distance x; The high-pressure gas chamber (101) comprises a release mechanism, which is a piston-type release mechanism or a double-break film-type release mechanism; The ratio of the volume of the high-pressure gas gun tube (103) to the volume of the high-pressure gas chamber (101) is ≥ 1.0; The high-pressure gas gun tube (103) is made of gun steel. 3. The ballistic target according to claim 1, characterized in that the electromagnetic ejection device (5) satisfies at least one of the following conditions: The electromagnetic transmitting tube (501) is made of a resin-based composite material or a ceramic material, and the maximum operating temperature can reach 260 degrees Celsius; The number of stages of the multi-stage driving coil (502) of the electromagnetic ejection device (5) is n, where n≥3; The structural parameters and electromagnetic parameters of the driving coils (502) and the excitation power supply (505) at each level are the same; The ratio of the length of each stage driving coil (502) to the inner diameter of the electromagnetic transmitting tube (501) is 0.4 to 1.7; The ratio of the distance between adjacent end faces of adjacent stage driving coils (502) to the inner diameter of the electromagnetic transmitting tube (501) is 0.1 to 0.3; The conductor of the driving coil (502) is made of copper, and the outside of the conductor of the driving coil (502) is covered with insulating material; The exterior of the multi-stage driving coil (502) is entirely covered by a metal layer (503). 4. The ballistic target according to claim 1 is characterized in that the excitation power supply (505) comprises an energy storage pulse capacitor group (50501), a main switch (50502), and a freewheeling switch (50503); the energy storage pulse capacitor group (50501) is connected in series with the main switch (50502), and is connected in parallel with the freewheeling switch (50503) at both ends of the driving coil (502); the two ends of the energy storage pulse capacitor group (50501) are also connected to the two ends of the charger (504) through a charging switch (50401); the on and off of the main switch (50502) and the charging switch (50401) are controlled by the measurement and control system (8). 5. The ballistic target according to claim 4, characterized in that the excitation power supply (505) satisfies at least one of the following: The energy storage pulse capacitor group (50501) is composed of a combination of metallized film self-healing pulse capacitors, the energy volume ratio of the metallized film self-healing pulse capacitor is greater than or equal to 0.5MJ/m ³ , and the working life is greater than or equal to 1000 times; The main switch (50502) is a spark gap switch or a high-voltage switch composed of a semiconductor thyristor; The freewheeling switch (50503) is composed of a combination of semiconductor high-voltage diodes. 6. The ballistic target according to claim 1, characterized in that the measurement and control system (8) comprises a central controller (801), a pulse trigger circuit (802) and an armature speed measuring device (803); The armature speed measuring device (803) comprises a photoelectric sensor body (80301) and a plurality of photoelectric probes (80302), wherein the plurality of photoelectric probes (80302) are installed at intervals on the wall of the high-pressure gas gun tube (103) and the electromagnetic transmitting tube (501) along the moving direction of the armature (2), and the photoelectric sensor body (80301) and the photoelectric probes (80302) are connected via optical fibers; The photoelectric probe (80302) sends a pulse light signal to the armature (2) through the through holes on the wall of the high-pressure gas gun tube (103) and the electromagnetic transmitting tube (501) and receives the reflected light signal, and the photoelectric sensor body (80301) converts the light signal into an electrical signal and transmits it to the central controller (801); The central controller (801) processes the electrical signal to obtain the time and speed at which the armature (2) passes through the photoelectric probe (80302), and calculates the estimated triggering time of the to-be-triggered stage according to the timing triggering control method; At the expected triggering moment, the central controller (801) sends a trigger control signal to the pulse triggering circuit (802), and the pulse triggering circuit (802) outputs a power pulse to trigger the switching on of the to-be-triggered stage excitation power supply (505), so that the energy storage pulse capacitor group (50501) of the to-be-triggered stage excitation power supply (505) is discharged through the driving coil (502). 7. The ballistic target according to claim 6, characterized in that the photoelectric probe (80302) is used to detect the rear end of the armature (2). 8. The ballistic target according to claim 6 or 7, characterized in that at least m photoelectric probes G _f1 , G _f2 , ..., G _fi-1 , G _fi , ..., G _fm-1 , G _fm are evenly arranged axially backward from the center line of the first-stage driving coil, the axial spacing between the first photoelectric probe G _f1 and the center line of the first-stage driving coil is h/2, and the axial spacing between adjacent photoelectric probes is h.

The speed of the armature (2) at the center line of the first-stage driving coil in the electromagnetic transmitting tube (501) is v _za , and t _m is the time interval when the discharge current of the driving coil rises from zero to a maximum value; At least n photoelectric probes _Gz1 , _Gz2 , ..., _Gzj , Gzj ₊₁ , ..., _Gzn-1 , _Gzn are evenly arranged axially forward from the center line of the first-level driving coil. The first photoelectric probe _Gz1 is located on the tube wall between the first-level driving coil and the second-level driving coil. The distance between the first photoelectric probe _Gz1 and the center line of the first-level driving coil is equal to the distance between the first photoelectric probe _Gz1 and the center line of the second-level driving coil. The axial interval between adjacent photoelectric probes is h. 9. The ballistic target according to claim 8, characterized in that

10. The ballistic target according to claim 8, wherein _tm is based on

It is determined that _Ld is the sum of all self-inductances of the discharge circuit before the discharge current of the driving coil is freewheeling through the diode, and C is the capacitance value of the energy storage capacitor group. 11. The ballistic target according to claim 8, wherein the timing trigger control method comprises: Step 1: The high-pressure gas chamber (101) releases gas to drive the armature (2) to push the model (3) forward; Step 2: Let s = 1. When the armature (2) moves past the mth photoelectric probe behind the center line of the first-stage drive coil, i = m. Circulate the following steps 2-1 and 2-2 until the first-stage excitation power supply is triggered: Step 2-1: When the armature (2) moves past the i-th photoelectric probe behind the center line of the first-stage driving coil, the distance between the armature (2) and the center line of the first-stage driving coil is l _fi1 =(i-1/2)h. The armature speed measuring device (803) performs measurement and the central controller (801) performs signal processing to obtain the speed v _fi of the armature (2) at this moment and this position; Step 2-2: if

Then the first stage excitation power supply is triggered after a delay time Δt ₁ , and the delay time Δt ₁ satisfies:

Let s=s+1, let i=i-1, jump out of this loop and execute step 3; if

Then no excitation power supply is to be triggered, and i=i-1; Step 3: cyclically execute the following steps 3-1 and 3-2 until the armature (2) passes the first photoelectric probe behind the center line of the first-stage driving coil and passes the center line of the first-stage driving coil; Step 3-1: When the armature (2) moves to the i-th photoelectric probe behind the center line of the first-stage driving coil, the distance between the armature (2) and the center line of the s-th-stage driving coil is l _fis =(i+s-3/2)h. The armature speed measuring device (803) performs measurement and the central controller (801) performs signal processing to obtain the speed v _fi of the armature (2) at this moment and this position; Step 3-2: if

Then the s-th level excitation power supply is triggered immediately, let s = s + 1, let i = i - 1; if

Then the s-th level excitation power supply is triggered after a delay time Δt _s , and the delay time Δt _s satisfies:

Let s = s + 1, let i = i - 1; if

Then no excitation power supply is to be triggered, and i=i-1; Step 4: When the armature (2) passes through the center line of the first-stage drive coil and moves to the first photoelectric probe _Gz1 in front of the center line of the first-stage drive coil, the s-stage excitation power supply is triggered and turned on. This moment is _ts , and the distance between the armature (2) and the center line of the first-stage drive coil is _xs = h/2; the armature speed measuring device (803) performs measurement, and the central controller (801) performs signal processing to obtain the speed _vs of the armature (2) at this position at the moment _ts ; Step 5: cyclically execute the following steps 5-1, 5-2 and 5-3 until the time t _n at which the n-th stage excitation power supply is turned on is obtained: Step 5-1: triggering and turning on the s+1th level excitation power supply at time ts ₊₁ , wherein the time _ts+1 satisfies:

v _s is the speed of the armature (2) at time t _s , a is the average acceleration of the armature (2) motion, h is the center distance between two adjacent driving coils, and 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; Step 5-2: The central controller (801) calculates the estimated speed of the armature (2) at time _ts+1 to be

Step 5-3: Let s=s+1. 12. The ballistic target according to claim 11, characterized in that the distance _xs+1 between the center line of the armature (2) and the first-stage driving coil at time ts ₊₁ satisfies: xs ₊₁ = _xs +h- _atm ( _ts+1 - _ts )< _xs +h, where _xs is the distance between the center line of the armature (2) and the first-stage driving coil at time _ts . 13. The ballistic target according to claim 11, characterized in that the time and speed when the armature (2) passes the jth photoelectric probe _Gzj and the j+1th photoelectric probe Gzj ₊₁ in front of the center line of the first-stage driving coil are _tzj , _vzj and _tzj+1 , vzj ₊₁ respectively, and the time and speed when the armature (2) passes the j+1th photoelectric probe _Gzj+1 in front of the center line of the first-stage driving coil are

14. The ballistic target according to claim 1, characterized in that the ballistic target satisfies at least one of the following: The high-pressure gas gun tube (103) and the electromagnetic launch tube (501) are coaxial with each other and have the same inner diameter, which is not less than 50 mm; The high-pressure gas gun tube (103) is connected to the electromagnetic launch tube (501) via a flange structure; The high-pressure gas gun tube (103) or the electromagnetic launch tube (501) is connected to each other in sections by pipes of the same specification, and each section is connected by a flange structure, a Hough nut structure or a Hough clamp structure; The armature (2) is in the form of an integral solid cylinder or a hollow cylinder; The armature (2) is made of aluminum or aluminum alloy; 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) passes through an expansion box (6) and enters a test chamber (7) after firing. When the model (3) is a combined model with a buttstock, the combined model consists of a model body and a buttstock. After the model (3) is fired, the buttstock and the model body are separated in the expansion box (6), and the model body enters the test chamber (7). The expansion tank (6) and the test chamber (7) are equipped with a model velocity measurement system, a camera system for measuring the position and posture of the model (3), a shadow/schlieren instrument for flow field display, and a light radiation measurement system for measuring light radiation characteristics; The ballistic target comprises a plurality of supporting mechanisms and a track system, wherein the supporting mechanisms are respectively located below the high-pressure gas chamber (101), the high-pressure gas gun tube (103), the electromagnetic launch tube (501), the expansion tank (6) and the test chamber (7), and the supporting mechanisms are installed on the track system and can move along the track; The charger (504) adopts an IGBT series resonant constant current charging power supply; The test gas filled in the high-pressure gas gun tube (103) in front of the model (3), the electromagnetic launch tube (501), the expansion box (6) and the test chamber (7) is air, and the air pressure is 10Pa to 0.2MPa; The speed v za of the armature (2) at the center line of the first-stage driving coil in the electromagnetic transmitting tube (501) _satisfies 0＜v _za ≤1500m/s. 15. A timing trigger control method, characterized in that the method is applied to the ballistic target according to any one of claims 8 to 13, and the method comprises: Step 1: The high-pressure gas chamber releases gas to drive the armature to push the model forward; Step 2: Let s = 1. When the armature moves past the mth photoelectric probe behind the center line of the first-stage drive coil, i = m. Circulate the following steps 2-1 and 2-2 until the first-stage excitation power supply is triggered: Step 2-1: When the armature moves past the ith photoelectric probe behind the center line of the first-stage drive coil, the distance between the armature and the center line of the first-stage drive coil is l _fi1 =(i-1/2)h. The armature speed measuring device performs measurement and the central controller performs signal processing to obtain the armature speed v _fi at this moment and this position; Step 2-2: if

Then the first stage excitation power supply is triggered after a delay time Δt ₁ , and the delay time Δt ₁ satisfies:

Let s=s+1, let i=i-1, jump out of this loop and execute step 3; if

Then no excitation power supply is to be triggered, and i=i-1; Step 3: Circulate the following steps 3-1 and 3-2 until the armature passes the first photoelectric probe behind the center line of the first-stage drive coil and passes the center line of the first-stage drive coil; Step 3-1: When the armature moves to the i-th photoelectric probe behind the center line of the first-stage drive coil, the distance between the armature and the center line of the s-th-stage drive coil is l _fis =(i+s-3/2)h. The armature speed measuring device performs measurement and the central controller performs signal processing to obtain the armature speed v _fi at this moment and this position; Step 3-2: if

Then the s-th level excitation power supply is triggered immediately, let s = s + 1, let i = i - 1; if

Then the s-th level excitation power supply is triggered after a delay time Δt _s , and the delay time Δt _s satisfies:

Let s = s + 1, let i = i - 1; if

Then no excitation power supply is to be triggered, and i=i-1; Step 4: When the armature passes through the center line of the first-stage drive coil and moves to the first photoelectric probe _Gz1 in front of the center line of the first-stage drive coil, the s-stage excitation power supply is triggered and turned on. This moment is _ts , and the distance between the armature and the center line of the first-stage drive coil is _xs = h/2; the armature speed measuring device performs measurement and the central controller performs signal processing to obtain the armature speed _vs at this position at time _ts ; Step 5: cyclically execute the following steps 5-1, 5-2 and 5-3 until the time t _n at which the n-th stage excitation power supply is turned on is obtained: Step 5-1: triggering and turning on the s+1th level excitation power supply at time ts ₊₁ , wherein the time _ts+1 satisfies:

v _s is the armature speed at time t _s , a is the average acceleration of the armature motion, h is the center distance between two adjacent drive coils, and t _m is the time interval when the discharge current of the drive coil changes from zero to the maximum value; Step 5-2: The central controller calculates the estimated armature speed at time _ts+1 :

Step 5-3: Let s=s+1.

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