A ballistic target based on electromagnetic catapult-assisted three-stage light gas gun

Abstract

A ballistic target based on an electromagnetic catapult-assisted three-stage light gas gun includes a first-stage gas propulsion section, an electromagnetic catapult device, an armature, a first-stage piston, a first-stage high-pressure pump pipe, a first- and second-stage connecting mechanism, a second-stage pump pipe, a second-stage piston, a second- and third-stage connecting mechanism, a projectile, a launch tube, an expansion tank, a test chamber, and a measurement and control system. The first-stage gas chamber releases high-pressure gas to drive the armature and the first-stage piston forward and out of the first-stage gas pump pipe. Within the first-stage electromagnetic pump pipe, the armature pushes the first-stage piston to move and compress the light gas under the combined action of the high-pressure gas thrust and electromagnetic force. The high-pressure light gas in the second-stage gas chamber breaks through the second-stage diaphragm, pushing the second-stage piston to compress the light gas in the second-stage pump pipe. The high-temperature and high-pressure light gas in the third-stage gas chamber breaks through the third-stage diaphragm, driving the projectile at high speed out of the launch tube, through the expansion tank, and into the test chamber. The present invention improves the driving capacity of traditional three-stage light gas guns by several times, and has better and more controllable interior ballistic performance. It is also safer, cleaner, and more efficient.

Description

Technical Field

[0001] The present application relates to the technical field of hypervelocity flight ground simulation test or hypervelocity collision loading test, and in particular to a ballistic target based on a three-stage light gas gun assisted by electromagnetic catapult drive. Background Art

[0002] A ballistic target is an aerodynamic ground test device that allows aerodynamic test projectiles to fly freely in a static atmosphere. It can simulate real-world flight flow conditions and is suitable for conducting tests such as aerodynamic / thermal, aerodynamic physics, and hypervelocity impact tests. A ballistic target primarily consists of a projectile launcher, a test system, and a measurement and control system. The power source for a ballistic target launcher is typically gunpowder, compressed gas, or hydrogen-oxygen detonation, with a two-stage gunpowder-driven light gas cannon being the most common. Traditional two-stage guns use gunpowder as the driving force. The high-pressure gas from the gunpowder combustion propels a piston at high speed, compressing the light gas (hydrogen or helium) in the pump tube to a high temperature and high pressure. This high-pressure light gas then propels the projectile to the desired test velocity. Due to the safety, uncertainty, and driving capacity limitations of gunpowder, the launch velocity of gunpowder-driven ballistic targets currently typically ranges from 2 km / s to 6 km / s. Currently, space debris impacting spacecraft can reach maximum velocities exceeding 14 km / s, with an average impact velocity of 9 km / s. Spacecraft protection assessment urgently requires hypervelocity impact ground simulation test equipment with stronger driving capabilities and higher projectile launch velocities to support experimental research.

[0003] In recent years, to enhance driving capabilities and increase projectile launch speeds, China has intensified research on power sources and structural forms for light gas guns. Chinese Patent Publication No. CN102778171B, published on April 22, 2015, is titled "A Three-Stage Light Gas Gun Powered by Compressed Nitrogen." The application discloses a three-stage light gas gun powered by compressed nitrogen in the first stage. The front section of the launch tube incorporates a replaceable ablation ring, which improves interstage energy utilization and reduces the risk of ablation within the gun itself, resulting in greater safety than gunpowder and hydrogen-oxygen detonation methods. However, the driving capability remains relatively weak, and the ability to launch large-mass projectiles (over 1g) at ultra-high speeds exceeding 8km / s is insufficient.

[0004] Chinese patent publication number CN106895739A, publication date June 27, 2017, is titled "Three-stage light gas gun based on hydrogen-oxygen mixed detonation." The application discloses a three-stage light gas gun with a first-stage drive using a hydrogen-oxygen mixed detonation method. The gun has a stronger loading capacity than high-pressure nitrogen and can stably launch a 1g projectile at a speed exceeding 10km / s. However, its shortcomings are that the mass and size of the projectile are relatively small, and the driving capacity still needs to be improved. At the same time, the domestic management requirements for flammable gases are strict, and the technical safety, reliability, and test economy are relatively poor.

[0005] Chinese patent publication number 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. Compared with traditional drive methods, it has stronger driving ability and better internal ballistic performance, is safer than gunpowder drive, mixed gas detonation and other methods, occupies less space and has a higher firing speed than high-pressure nitrogen-driven two-stage light gas guns; however, its shortcomings are that compared with traditional drive methods, the initial acceleration is slow and the overall cost is high (especially the pulse power supply system including the energy storage pulse capacitor group), and because it is still a two-stage light gas gun structure, the stable firing speed of the projectile still needs to be improved. At the same time, when the filling parameters are not ideal, the plastic piston is prone to rebound near the secondary air chamber, resulting in insufficient compression or equipment damage. Summary of the Invention

[0006] The purpose of the present invention is to solve the problems of weak driving capability, insufficient projectile launch speed, and poor interior ballistic performance of the existing three-stage light gas gun as the core launch device of the ballistic target, explore the potential of the driving mode of the electromagnetic catapult device, and provide a three-stage light gas gun with a first stage that uses a high-pressure gas and electromagnetic catapult series composite drive as a launch device for an ultra-high-speed ballistic target. The driving capability is improved, so that the projectile can stably reach a launch speed of more than 9 km / s, and even a launch speed of more than 14 km / s, meeting the requirements of ground simulation tests of hypervelocity impacts of space debris on spacecraft. At the same time, the interior ballistic performance is improved, and a high-speed, efficient, controllable, safe, and clean test platform is provided for tests such as aerodynamic / thermal, aerodynamic physics, and hypervelocity collisions.

[0007] In the first aspect, a ballistic target for a three-stage light gas gun driven by an electromagnetic catapult is provided, comprising a first-stage gas propulsion section, an electromagnetic catapult device, an armature, a first-stage piston, a first-stage high-pressure pump pipe, a first- and second-stage connecting mechanism, a second-stage pump pipe, a second-stage piston, a second- and third-stage connecting mechanism, a projectile, a launch tube, an expansion tank, a test chamber, and a measurement and control system; wherein,

[0008] The first-stage gas propulsion section includes a first-stage gas chamber and a first-stage gas pump pipe;

[0009] The electromagnetic ejection device includes a primary electromagnetic pump tube, a multi-stage drive coil wound on the primary electromagnetic pump tube, an excitation power supply for supplying power to the multi-stage drive coil, and a charger for charging the excitation power supply;

[0010] The first and second stage connection mechanism includes a second stage air chamber and a second stage diaphragm, and the second and third stage connection mechanism includes a third stage air chamber and a third stage diaphragm; the first stage gas pump pipe, the first stage electromagnetic pump pipe, the first stage high-pressure pump pipe, and the second stage air chamber are connected in sequence, the second stage air chamber is connected to the second stage pump pipe with a second stage diaphragm provided therebetween, the second stage pump pipe is connected to the third stage air chamber, the third stage air chamber is connected to the launch tube with a third stage diaphragm provided therebetween, and the launch tube is connected to the expansion tank and the test chamber in sequence;

[0011] The first-stage gas pump pipe inlet section is equipped with an armature and a first-stage piston, the armature is located behind the first-stage piston, the second-stage pump pipe inlet section is equipped with a second-stage piston, the second-stage piston is located in front of the second-stage diaphragm, and the launch tube inlet section is equipped with a projectile, the projectile is located in front of the third-stage diaphragm;

[0012] The first-stage air chamber releases high-pressure gas, driving the armature and the first-stage piston to move forward and fly out of the first-stage gas pump pipe;

[0013] The electromagnetic catapult device generates pulse current and pulse magnetic field through discharge of multi-stage driving coils;

[0014] The excitation power supply is triggered step by step to discharge the multi-stage drive coil step by step. The armature moves under the combined action of the gas thrust and the electromagnetic force generated by the multi-stage drive coil and pushes the first-stage piston. The first-stage piston flies out of the electromagnetic pump pipe and enters the first-stage high-pressure pump pipe.

[0015] The first-stage gas pump tube, the first-stage electromagnetic pump tube, the first-stage high-pressure pump tube and the second-stage air chamber in front of the first-stage piston are filled with light gas. The light gas in the first-stage gas pump tube, the first-stage electromagnetic pump tube, the first-stage high-pressure pump tube and the second-stage air chamber breaks through the second-stage diaphragm under the compression of the first-stage piston, pushing the second-stage piston forward in the second-stage pump tube;

[0016] The secondary pump tube and the tertiary air chamber in front of the secondary piston are filled with light gas. The light gas in the secondary pump tube and the tertiary air chamber breaks through the tertiary diaphragm under the compression of the secondary piston, driving the projectile to fly out of the launch tube and enter the test chamber through the expansion box;

[0017] 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.

[0018] In conjunction with the first aspect, in certain implementations of the first aspect, the first-stage gas propulsion section satisfies at least one of the following:

[0019] The gas in the primary gas chamber is air, nitrogen or helium, and the gas pressure is not greater than 30 MPa;

[0020] The first-level air chamber is connected to the first-level gas pump pipe through a flange structure or an open sawtooth thread structure; the first-level air chamber includes a release mechanism, which is a piston release mechanism or a double-break film release mechanism;

[0021] The ratio of the volume of the first-stage gas pump tube to the volume of the first-stage gas chamber is ≥1.0;

[0022] The primary gas pump tube is made of gun steel;

[0023] The inner wall roughness of the primary gas pump tube is Ra≤1.6;

[0024] The total pressure of gas in the first-level gas chamber P 1x and total temperature T 1x The expression is:

[0025]

[0026] Among them, γ1 is the specific heat ratio of high-pressure gas, P 10 is the initial pressure of the gas in the first-stage gas chamber, T 10 is the initial temperature of the gas in the first-stage gas chamber, V 10 is the initial volume of gas in the first-stage air chamber, x is the distance the armature moves, D is the inner diameter of the electromagnetic pump tube, V 1x (x) is the volume of gas when the armature moves a distance x.

[0027] In conjunction with the first aspect, in certain implementations of the first aspect, the electromagnetic catapult device satisfies at least one of the following:

[0028] The first-stage electromagnetic pump tube is made of high-strength resin-based composite material or high-strength ceramic material, and the maximum operating temperature can reach 260 degrees Celsius;

[0029] The charger is an IGBT series resonant constant current charging power supply;

[0030] The inner wall roughness of the first-stage electromagnetic pump tube is Ra≤1.6;

[0031] The ratio of the length of each stage driving coil of the electromagnetic catapult device to the inner diameter of the first stage electromagnetic pump tube is 0.4 to 1.7;

[0032] The ratio of the distance between adjacent end faces of adjacent stage driving coils to the inner diameter of the first stage electromagnetic pump tube is 0.1 to 0.3.

[0033] 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.

[0034] In conjunction with the first aspect, in certain implementations of the first aspect, the excitation power supply satisfies at least one of the following:

[0035] 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;

[0036] The main switch is a spark gap switch or a high-voltage switch composed of a semiconductor thyristor;

[0037] The freewheeling switch is composed of a combination of semiconductor high-voltage diodes.

[0038] In conjunction with the first aspect, in certain implementations of the first aspect, the primary high-pressure pump tube satisfies at least one of the following:

[0039] The ratio of the mass of the first-stage piston to the cross-sectional area of ​​the first-stage high-pressure pump pipe is greater than 500kg / m 2 ;

[0040] The first-level high-pressure pump pipe is made of gun steel;

[0041] The inner wall roughness of the first-level high-pressure pump pipe is Ra≤1.6.

[0042] In conjunction with the first aspect, in certain implementations of the first aspect, the secondary air chamber satisfies at least one of the following:

[0043] The total pressure of light gas in the secondary air chamber before the secondary diaphragm breaks is P 2x and total temperature T 2x The expression is:

[0044]

[0045] Where γ2 is the initial specific heat ratio of the light gas in the secondary chamber, P 20 is the initial pressure of the light gas in the secondary gas chamber, T 20 is the initial temperature of the light gas in the secondary chamber, V 20 is the initial total volume of the first-stage gas pump tube, first-stage electromagnetic pump tube, first-stage high-pressure pump tube, and second-stage air chamber in front of the first-stage piston, x is the movement distance of the first-stage piston, D is the inner diameter of the first-stage electromagnetic pump tube, V 2x (x) is the volume of light gas in the closed space between the primary piston and the secondary diaphragm when the primary piston moves a distance x;

[0046] The secondary air chamber includes a first large-diameter straight pipe section, a first variable-diameter section and a first small-diameter straight pipe section; the ratio of the length of the first large-diameter straight pipe section to the first variable-diameter section is 0.4 to 0.8, and the ratio of the length of the first small-diameter straight pipe section to the first variable-diameter section is 0.2 to 0.5; the first variable-diameter section adopts a conical cylinder structure with a first small cone angle, and the cone angle is 5° to 10°. The ratio of the length of the first-level high-pressure pump pipe to the first variable-diameter section of the secondary air chamber is 3 to 10.

[0047] In conjunction with the first aspect, in certain implementations of the first aspect, the secondary pump tube satisfies at least one of the following:

[0048] The secondary pump tube is made of gun steel;

[0049] The ratio of the inner diameter of the first-level high-pressure pump tube to the inner diameter of the second-level pump tube is 2.1 to 2.4;

[0050] The ratio of the inner diameter of the secondary pump tube to the inner diameter of the launch tube is 3.5 to 4.5;

[0051] The ratio of the length to the inner diameter of the secondary pump tube is 190 to 230;

[0052] The inner wall roughness of the secondary pump tube is Ra≤0.8.

[0053] In combination with the first aspect, in certain implementations of the first aspect, the three-stage air chamber includes a second large-diameter straight pipe section, a second variable-diameter section, and a second small-diameter straight pipe section, and the roughness of the inner wall of the three-stage air chamber is Ra≤0.8; the ratio of the length of the second large-diameter straight pipe section to the second variable-diameter section of the three-stage air chamber is 0.5~1.0, and the ratio of the length of the second small-diameter straight pipe section to the second variable-diameter section is 0.3~0.6; the cone angle of the second variable-diameter section of the three-stage air chamber is 10°~20°.

[0054] In conjunction with the first aspect, in certain implementations of the first aspect, the transmitting tube satisfies at least one of the following:

[0055] The launch tube is made of gun steel;

[0056] The ratio of the launch tube length to the inner diameter is 280 to 420;

[0057] The roughness of the inner wall of the launch tube is Ra≤0.8.

[0058] 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 an armature speed measuring device;

[0059] The armature speed measuring device includes a photoelectric sensor body and a plurality of photoelectric probes, the plurality of photoelectric probes being installed on the outer walls of the first-level gas pump pipe, the first-level electromagnetic pump pipe and the first-level high-pressure pump pipe at intervals along the movement direction of the armature, and the photoelectric sensor body and the photoelectric probes being connected via optical fibers;

[0060] The photoelectric probe sends a pulse light signal to the armature through the through holes on the walls of the first-level gas pump tube, the first-level electromagnetic pump tube and the first-level high-pressure pump 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;

[0061] The central controller processes the electrical signal to obtain the time and speed at which the armature passes the photoelectric probe, and calculates the expected triggering time of the to-be-triggered stage according to the timing triggering control method;

[0062] 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 is discharged through the driving coil.

[0063] 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.

[0064] In combination with the first aspect, in some implementations of the first aspect, at least m photoelectric probes are evenly arranged axially backward from the center line of the first-stage driving coil. The first photoelectric sensor G f1 The axial distance from the center line of the first-stage driving coil is h / 2, and the axial distance between adjacent photoelectric probes is h; v za is the speed of the armature at the center line of the first stage driving coil in the electromagnetic pump tube, t m It is the time interval when the discharge current of the driving coil rises from zero to the maximum value;

[0065] At least n photoelectric probes G are evenly arranged axially forward from the center line of the first-stage driving coil. z1 , G z2 ,…,G zj , G zj+1 ,…,G zn-1 , G zn , the first photoelectric sensor G z1 Located on the pipe wall between the first and second stage drive coils, the first photoelectric sensor G z1 The distance from the center line of the first stage driving coil is the same as the first photoelectric probe G z1 The distance between the center lines of the second-stage driving coil is equal, and the axial spacing between adjacent photoelectric probes is h.

[0066] In conjunction with the first aspect, in certain implementations of the first aspect,

[0067] In conjunction with the first aspect, in certain implementations of the first aspect, t m according to OK, L d It is the sum of all self-inductances of the discharge circuit before the discharge current of the driving coil is freewheeled by the diode, and C is the capacitance value of the energy storage capacitor group.

[0068] In conjunction with the first aspect, in certain implementations of the first aspect, the timing trigger control method includes:

[0069] Step 1: The first-stage air chamber releases gas to drive the armature to push the first-stage piston forward;

[0070] 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; repeat the following steps 2-1 and 2-2 until the first-stage excitation power supply is triggered:

[0071] Step 2-1: When the armature moves past 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 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 at this moment and this position fi ;

[0072] Step 2-2:

[0073] if Then the first stage excitation power supply is triggered after the delay time Δt1, and the delay time Δt1 satisfies: Let s = s + 1, let i = i - 1, jump out of this loop and execute step 3;

[0074] if Then no excitation power supply is to be triggered, and i=i-1;

[0075] Step 3: Repeat the steps 3-1 and 3-2 until the armature passes the first photoelectric probe behind the center line of the first-stage drive coil;

[0076] 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-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 at this moment and this position fi ;

[0077] Step 3-2:

[0078] if Then the s-th level excitation power supply is triggered immediately, let s = s + 1, let i = i - 1;

[0079] if Then at the delay time Δt s After triggering the s-th level excitation power supply, the delay time Δt s satisfy: Let s = s + 1, let i = i - 1;

[0080] if Then no excitation power supply is to be triggered, and i=i-1;

[0081] Step 4: When the armature passes through the center line of the first stage drive coil and moves to the first photoelectric probe G in front of the center line of the first stage drive coil z1 When the s-th level excitation power supply is triggered and turned on, this moment is t s , the distance between the armature and the center line of the first stage drive coil is x s =h / 2; the armature speed measuring device performs measurement and the central controller performs signal processing to obtain t s The armature speed v at this position at this moment s ;

[0082] Step 5: Loop through the following steps 5-1, 5-2, and 5-3 until the moment t at which the n-th stage excitation power supply is turned on is obtained. n :

[0083] Step 5-1: At time t s+1 Triggering the conduction of the s+1th level excitation power supply, the time t s+1 satisfy:

[0084] v s is time t s Armature speed, a is the average acceleration of armature motion, h is the center distance between two adjacent drive coils, t m It is the time interval from when the discharge current of the driving coil changes from zero to when it reaches the maximum value;

[0085] Step 5-2: Calculate the time t through the central controller s+1 The expected armature speed is

[0086]

[0087] Step 5-3: Let s=s+1.

[0088] In combination with the first aspect, in some implementations of the first aspect, at time t s+1 The distance between the armature and the center line of the first stage drive coil is x s+1 Satisfy: x s+1 =x s +h-at m (t s+1 -t s )<x s +h,x s is time t s The distance between the armature and the center line of the first-stage driving coil.

[0089] In combination with the first aspect, in certain implementations of the first aspect, the armature passes through the jth photoelectric probe G in front of the center line of the first stage drive coil. zj , j+1th photoelectric sensor G zj+1 The time and speed are t zj 、v zj and t zj+1 、v zj+1 , the armature passes the j+1th photoelectric probe G in front of the center line of the first stage drive coil zj+1 The estimated time and speed are

[0090] In conjunction with the first aspect, in certain implementations of the first aspect, the ballistic target satisfies at least one of the following:

[0091] The first-level gas pump pipe, the first-level electromagnetic pump pipe, and the first-level high-pressure pump pipe are coaxial with each other and have the same inner diameter, which is not less than 50 mm;

[0092] The light gas filled in the first-stage gas pump pipe, the first-stage electromagnetic pump pipe, the first-stage high-pressure pump pipe, the second-stage air chamber in front of the first-stage piston, the second-stage pump pipe in front of the second-stage piston, and the third-stage air chamber is hydrogen or helium, and the pressure of the hydrogen or helium is 0.01-1.0 MPa; the test gas filled in the launch tube, the expansion box and the test chamber in front of the projectile is air, and the air pressure is 10 Pa-0.2 MPa;

[0093] The inlet end of the first-level electromagnetic pump pipe is connected to the outlet end of the first-level gas pump pipe through a flange structure;

[0094] The outlet end of the first-stage electromagnetic pump pipe is connected to the inlet end of the first-stage high-pressure pump pipe through a flange structure;

[0095] When the first-level gas pump pipe, the first-level electromagnetic pump pipe, the first-level high-pressure pump pipe, the second-level pump pipe, and the launch pipe are connected to each other in sections of pipes of the same specifications, each section is connected by a flange structure, a Hough nut structure, or a Hough clamp structure;

[0096] The first large-diameter straight pipe section and the first small-diameter straight pipe section of the secondary air chamber are respectively provided with convex stoppers; the outlet end of the first-level high-pressure pump pipe is provided with a concave stopper; the inlet end of the secondary pump pipe is provided with a concave stopper, a secondary diaphragm groove, and a first tapered groove in sequence along the center line, the diameter of the concave stopper is larger than the secondary diaphragm groove, and a secondary diaphragm is placed in the secondary diaphragm groove; the diameter of the first tapered groove gradually decreases from one end of the diaphragm groove, the maximum diameter of the first tapered groove is smaller than the diameter of the secondary diaphragm groove, and the minimum diameter of the first tapered groove is equal to the inner diameter of the secondary pump pipe; the convex stopper of the first large-diameter straight pipe section of the secondary air chamber is adapted to the concave stopper at the outlet end of the first-level high-pressure pump pipe; the convex stopper of the first small-diameter straight pipe section of the secondary air chamber is adapted to the concave stopper at the inlet end of the secondary pump pipe;

[0097] The second large-diameter straight pipe section and the second small-diameter straight pipe section of the three-stage air chamber are respectively provided with convex stoppers; the outlet end of the secondary pump pipe is provided with a concave stopper; the inlet end of the launch tube is provided with a concave stopper, a three-stage diaphragm groove, and a second tapered groove in sequence along the center line, the diameter of the concave stopper is larger than the three-stage diaphragm groove, and a three-stage diaphragm is placed in the three-stage diaphragm groove; the diameter of the second tapered groove gradually decreases from one end of the diaphragm groove, the maximum diameter of the second tapered groove is smaller than the diameter of the three-stage diaphragm groove, and the minimum diameter of the second tapered groove is equal to the inner diameter of the launch tube; the convex stopper of the second large-diameter straight pipe section of the three-stage air chamber is adapted to the concave stopper at the outlet end of the secondary pump pipe; the convex stopper of the second small-diameter straight pipe section of the three-stage air chamber is adapted to the concave stopper at the inlet end of the launch tube;

[0098] The armature structure is an integral solid cylinder or a hollow cylinder;

[0099] The armature material is aluminum or aluminum alloy;

[0100] The structure of the first-stage piston or the second-stage piston is an integral cylindrical type or a three-stage type in which a piston head, a steel counterweight, and a piston tail are sequentially connected as one body. The piston head and piston tail of the first-stage piston or the second-stage piston are made of polyethylene or polytetrafluoroethylene.

[0101] The secondary diaphragm or tertiary diaphragm adopts a flat plate structure and is provided with a "cross"-shaped four-petal groove or an "*"-shaped six-petal groove; the secondary diaphragm or tertiary diaphragm is made of austenitic stainless steel or aluminum alloy with a tensile strength greater than 500 MPa;

[0102] The projectile is a full-caliber projectile without a sabot or a combined projectile with a sabot. When the projectile is a full-caliber projectile without a sabot, the ratio of the projectile length to the diameter is greater than 0.5. After the projectile is fired, it passes through an expansion box and enters the test chamber. When the projectile is a combined projectile with a sabot, the combined projectile consists of a projectile body and a sabot. The sabot is a split-petal combination structure with two to eight petals, and the sabot material is polycarbonate, high-pressure polyethylene, or nylon. After the projectile is fired, the sabot and the projectile body are separated in the expansion box, and the projectile body enters the test chamber.

[0103] The expansion tank and the test chamber are equipped with a projectile velocity measurement system, a camera system for measuring the projectile position and posture, a shadow / schlieren instrument for flow field display, and a light radiation measurement system for measuring light radiation characteristics;

[0104] The ballistic target includes several supporting mechanisms and a track system. The supporting mechanisms are respectively located under the first-level gas chamber, the first-level gas pump pipe, the first-level electromagnetic pump pipe, the first-level high-pressure pump pipe, the second-level pump pipe, the launch pipe, the expansion tank and the test chamber. The supporting mechanisms are installed on the track system and can move along the track.

[0105] The speed of the armature at the center line of the first stage driving coil in the first stage electromagnetic pump tube is v za , the outlet velocity of the first-stage electromagnetic pump tube is v zb , 0<v za <v zb ≤1000m / s.

[0106] 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, the method comprising:

[0107] Step 1: The first-stage air chamber releases gas to drive the armature to push the first-stage piston forward;

[0108] 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; repeat the following steps 2-1 and 2-2 until the first-stage excitation power supply is triggered:

[0109] Step 2-1: When the armature moves past 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 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 at this moment and this position fi ;

[0110] Step 2-2:

[0111] if Then the first stage excitation power supply is triggered after the delay time Δt1, and the delay time Δt1 satisfies: Let s = s + 1, let i = i - 1, jump out of this loop and execute step 3;

[0112] if Then no excitation power supply is to be triggered, and i=i-1;

[0113] Step 3: Repeat the steps 3-1 and 3-2 until the armature passes the first photoelectric probe behind the center line of the first-stage drive coil;

[0114] 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-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 at this moment and this position fi ;

[0115] Step 3-2:

[0116] if Then the s-th level excitation power supply is triggered immediately, let s = s + 1, let i = i - 1;

[0117] if Then at the delay time Δt s After triggering the s-th level excitation power supply, the delay time Δt s satisfy: Let s = s + 1, let i = i - 1;

[0118] if Then no excitation power supply is to be triggered, and i=i-1;

[0119] Step 4: When the armature passes through the center line of the first stage drive coil and moves to the first photoelectric probe G in front of the center line of the first stage drive coil z1 When the s-th level excitation power supply is triggered and turned on, this moment is t s , the distance between the armature and the center line of the first stage drive coil is x s =h / 2; the armature speed measuring device performs measurement and the central controller performs signal processing to obtain t s The armature speed v at this position at this moment s ;

[0120] Step 5: Loop through the following steps 5-1, 5-2, and 5-3 until the moment t at which the n-th stage excitation power supply is turned on is obtained. n :

[0121] Step 5-1: At time t s+1 Triggering the conduction of the s+1th level excitation power supply, the time t s+1 satisfy:

[0122] v s is time t s Armature speed, a is the average acceleration of armature motion, h is the center distance between two adjacent drive coils, t m It is the time interval from when the discharge current of the driving coil changes from zero to when it reaches the maximum value;

[0123] Step 5-2: Calculate the time t through the central controller s+1 The expected armature speed is

[0124]

[0125] Step 5-3: Let s=s+1.

[0126] Compared with the existing technology, the solution provided by this application includes at least the following beneficial technical effects:

[0127] (1) Light gas guns powered by gunpowder, high-pressure gas, etc. have a theoretical upper limit on the launch speed, while multi-stage coil electromagnetic drive has the characteristics of axial distribution, multi-stage accumulation, and modular integration. In theory, there is almost no upper limit on energy output and speed when conditions such as power supply, site, and energy storage allow. The first-stage drive of the launch device of the present invention is connected in series with the electromagnetic catapult device after the high-pressure gas. On the basis of giving full play to the driving capacity of the high-pressure gas, the electromagnetic driving capacity can be superimposed by increasing the number of excitation power supplies and driving coils along the axial direction according to the required total energy storage requirements calculated according to the required kinetic energy and energy conversion efficiency, thereby effectively improving the overall driving capacity. Compared with traditional driving methods such as gunpowder, hydrogen-oxygen detonation, and high-pressure gas, the driving capacity can be increased by at least several times. Under the condition of a certain launch tube caliber or projectile size and mass, the projectile launch speed can be greatly improved, so that gram-level projectiles can stably reach a launch speed of more than 9 km / s, or even a launch speed of more than 14 km / s, which can meet the ground simulation test requirements of space debris hypervelocity impact on spacecraft.

[0128] (2) The first-stage drive of the launch device of the present invention adopts a composite drive mode of high-pressure gas and electromagnetic ejection in series. Since there is a certain proportional relationship between the inner diameters of the first-stage electromagnetic pump tube, the second-stage pump tube and the launch tube, the improvement of the first-stage drive capability can increase the inner diameters of the first-stage electromagnetic pump tube, the second-stage pump tube and the launch tube, as well as the size and mass of the projectile while ensuring a certain ultra-high launch speed, thereby expanding and improving the parameter range of the hypervelocity collision simulation projectile.

[0129] (3) Both high-pressure gas drive alone and multi-stage electromagnetic drive alone have their own unique internal ballistic characteristics. When driven by high-pressure gas alone, the initial acceleration of the projectile is fast, but the base pressure decreases rapidly, which cannot provide a high average pressure for the projectile, resulting in poor internal ballistic performance and weak follow-up. Compared with high-pressure gas drive alone, the initial acceleration is slow when driven by electromagnetic catapult alone. The first-stage drive of the present invention is connected in series with the electromagnetic catapult device after the high-pressure gas, which can combine the advantages of the driving characteristics of the two methods. First, the armature is driven by high-pressure gas to accelerate quickly, and a certain initial velocity is given to the armature when the electromagnetic catapult is started. Then, the electromagnetic catapult device is used to continuously and efficiently energize. At the same time, by utilizing the characteristics of axial distribution of the excitation power supply and the drive coil, multi-stage energization, and independent regulation of the single stage, the energy storage and energization schemes are optimized by regulating the circuit structure parameters and electromagnetic parameters of each level, ensuring a high energy conversion efficiency while improving the internal ballistic characteristics through overall regulation.

[0130] (4) The first-stage drive of the present invention adopts a series structure of a high-pressure gas propulsion section and an electromagnetic catapult device. When the filling parameters are not ideal and the plastic piston rebounds near the secondary air chamber, the piston and armature moving in the opposite direction will reversely compress the gas in the first-stage air chamber of the high-pressure gas propulsion section, the gas pump pipe, the electromagnetic pump pipe of the electromagnetic catapult device, and the high-pressure pump pipe. Due to the "air cushion" effect of the space such as the first-stage air chamber, it can play a damping role in buffering the reverse movement of the piston, so that the piston and armature gradually decelerate in the opposite direction or oscillate and decelerate until they stop, thereby preventing damage to the equipment and pipelines.

[0131] (5) Due to the high cost of electrical equipment such as the pulse power supply system of the energy storage pulse capacitor group, when the output of kinetic energy is the same, the construction cost of a single electromagnetic catapult drive device is higher than that of a single high-pressure gas drive device (especially in flight ground simulation research institutions with relatively complete compressed gas facilities). The launch first-stage drive of the present invention adopts a composite method of high-pressure gas and electromagnetic catapult device in series. On the basis of giving full play to the driving capabilities of the two driving methods, the cost characteristics of the driving methods are comprehensively balanced. Under the condition of the same overall driving capability, the construction cost is lower than that of a single electromagnetic catapult drive device.

[0132] (6) The first-stage drive of the present invention adopts the electromagnetic force generated by the discharge induction of multi-stage electromagnetic coils as a safe, clean and efficient power source, which can 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.

[0133] (7) With the breakthrough of high energy density energy storage technology, high voltage switch technology and high strength new insulation material technology bottlenecks, the future synchronous electromagnetic coil propulsion device can be modularized, miniaturized, lightweight and intelligent. Electromagnetic thrust will have more and more advantages as an independent power source or an important part of the power source of light gas guns and ballistic targets. BRIEF DESCRIPTION OF THE DRAWINGS

[0134] Figure 1 This is a schematic diagram of the ballistic target structure of a three-stage light gas gun based on electromagnetic catapult assisted drive;

[0135] Figure 2 This is a schematic diagram of the electromagnetic catapult device and the timing measurement and control system;

[0136] Figure 3 Schematic diagram of the arrangement of the armature speed measuring device and the principle of the timing trigger control method;

[0137] Figure 4 This is a schematic diagram of the structure of the first-stage gas propulsion section;

[0138] Figure 5 This is a schematic diagram of the flange connection structure between the first-stage gas chamber and the first-stage gas pump pipe;

[0139] Figure 6This is a schematic diagram of the Hough nut connection structure between the segments of the first-stage gas pump pipe;

[0140] Figure 7 This is a schematic diagram of the flange connection structure between the first-stage gas pump pipe and the first-stage electromagnetic pump pipe;

[0141] Figure 8 This is a schematic diagram of the flange connection structure between the segments of the first-stage electromagnetic pump pipe;

[0142] Figure 9 This is a schematic diagram of the flange connection structure between the first-stage electromagnetic pump pipe and the first-stage high-pressure pump pipe;

[0143] Figure 10 This is a schematic diagram of the flange connection structure between the segments of the first-level high-pressure pump pipe;

[0144] Figure 11 It is a structural diagram of the first and second level connection mechanism;

[0145] Figure 12 This is a schematic diagram of the flange connection structure between the secondary pump pipe sections;

[0146] Figure 13 It is a schematic diagram of the structure of the second and third level connection mechanism;

[0147] Figure 14 This is a schematic diagram of the flange connection structure between launch tube segments;

[0148] Figure 15 This is a top-down schematic diagram of the expansion tank, test chamber and related measurement and control equipment.

[0149] Description of Figure Numbers:

[0150] 1-First-stage gas propulsion section; 101-First-stage gas chamber; 10101-First-stage gas chamber cavity; 10102-Exhaust cavity; 10103-Compensating hole; 10104-Buffer cavity; 10105-Check valve; 10106-Damping cavity; 10107-Spring; 10108-Valve body; 10109-Inlet valve; 10110-Exhaust valve; 102-Connecting mechanism A; 10201-Steel flange fitting Aa; 10202-Steel flange fitting Ab; 10203-Steel bolt assembly Ac; 103-First-stage gas pump pipe; 10301-First-stage gas pump pipe section k; 10302-First-stage gas pump pipe section k+1; 104-Haff nut assembly;

[0151] 2-Armature;

[0152] 3-First-stage piston;

[0153] 4-Connection mechanism B; 401-Steel flange pipe fitting Ba; 402-Insulation flange pipe fitting Bb; 403-Bolt assembly Bc;

[0154] 5 - Electromagnetic ejection device; 501 - First-stage electromagnetic pump pipe; 50101 - First-stage electromagnetic pump pipe section k; 50102 - First-stage electromagnetic pump pipe section k+1; 502 - Driving coil; 503 - Metal layer; 504 - Charger; 50401 - Charging switch; 505 - Excitation power supply; 50501 - 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;

[0155] 6-Connection mechanism D; 601-Insulation flange pipe fitting Da; 602-Steel flange pipe fitting Db; 603-Bolt assembly Dc;

[0156] 7-First-stage high-pressure pump pipe; 701-First-stage high-pressure pump pipe section k; 702-First-stage high-pressure pump pipe section k+1; 703-Steel flange connection mechanism E; 70301-Steel flange pipe fitting Ea; 70302-Steel flange pipe fitting Eb; 70303-Steel bolt assembly Ec;

[0157] 8-first and second level connection mechanism; 801-second level diaphragm; 802-second level air chamber; 803-steel flange pipe fitting Fa; 804-steel flange pipe fitting Fb; 805-steel bolt assembly Fc;

[0158] 9-Secondary piston;

[0159] 10-Secondary pump pipe; 1001-Secondary pump pipe section k; 1002-Secondary pump pipe section k+1; 1003-Steel flange connection mechanism G; 100301-Steel flange pipe fitting Ga; 100302-Steel flange pipe fitting Gb; 100303-Steel bolt assembly Gc;

[0160] 11-Second and third stage connection mechanism; 1101-Third stage diaphragm; 1102-Third stage air chamber; 1103-Steel flange pipe fitting Ha; 1104-Steel flange pipe fitting Hb; 1105-Steel bolt assembly Hc;

[0161] 12-projectiles;

[0162] 13-launching tube; 1301-launching tube section k; 1302-launching tube section k+1; 1303-steel flange connection mechanism J; 130301-steel flange pipe fitting Ja; 130302-steel flange pipe fitting Jb; 130303-steel bolt assembly Jc;

[0163] 14-Expansion tank; 1401-Expansion tank and vacuum system interface; 1402-Expansion tank side observation window; 1403-Expansion tank top observation window;

[0164] 15-Test chamber; 1501-Interface between test chamber and vacuum system; 1502-Observation window on the side of test chamber; 1503-Observation window on the top of test chamber;

[0165] 16 - Measurement and control system; 1601 - Central controller; 1602 - Pulse trigger circuit; 1603 - Armature speed measuring device; 160301 - Photoelectric sensor body; 160302 - Photoelectric probe; 1604 - Excitation power supply voltage measuring device; 1605 - Driving coil current measuring device; 1606 - Projectile speed measuring device in expansion chamber; 1607 - Binocular vision measurement system for expansion chamber; 1608 - Projectile speed measuring device in test chamber; 1609 - Schlieren instrument in test chamber; 1610 - Binocular vision measurement system in test chamber; 1611 - Optical radiation measuring instrument in test chamber;

[0166] 17-support mechanism;

[0167] 18-Track system. DETAILED DESCRIPTION

[0168] 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.

[0169] 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.

[0170] like Figure 1 、 Figure 2 、 Figure 4 and Figure 5 As shown, a ballistic target based on a three-stage light gas gun driven by an electromagnetic catapult auxiliary drive includes a first-stage gas propulsion section 1, an armature 2, a first-stage piston 3, a connecting mechanism B4, an electromagnetic catapult device 5, a connecting mechanism D6, a first-stage high-pressure pump pipe 7, a first- and second-stage connecting mechanism 8, a second-stage piston 9, a second-stage pump pipe 10, a second- and third-stage connecting mechanism 11, a projectile 12, a launch tube 13, an expansion tank 14, a test cabin 15, a measurement and control system 16, a support mechanism 17, and a track system 18.

[0171] The first-stage gas propulsion section 1 includes a first-stage gas chamber 101 and a first-stage gas pump tube 103. The electromagnetic ejection device includes a first-stage electromagnetic pump tube 501, a multi-stage drive coil 502 wound around the first-stage electromagnetic pump tube 501, an excitation power supply 505 that powers the multi-stage drive coil, and a charger 504 that charges the excitation power supply 505. In one embodiment, the charger 504 is an IGBT series resonant constant current charging power supply. The first-stage and second-stage connection mechanism includes a second-stage gas chamber 802 and a second-stage diaphragm 801. The second-stage and third-stage connection mechanism includes a third-stage gas chamber 1102 and a third-stage diaphragm 1101.

[0172] The primary gas pump tube 103, the primary electromagnetic pump tube 501, the primary high-pressure pump tube 7, and the secondary air chamber 802 are connected in sequence. The secondary air chamber 802 is connected to the secondary pump tube 10, with the secondary diaphragm 801 interposed therebetween. The secondary pump tube 10 is connected to the tertiary air chamber 1102. The tertiary air chamber 1102 is connected to the launch tube 13, with the tertiary diaphragm 1101 interposed therebetween. The launch tube 13 is connected in sequence to the expansion tank 14 and the test chamber 15.

[0173] The inlet section of the primary gas pump tube 103 houses the armature 2 and the primary piston 3, with the armature 2 positioned behind the primary piston 3. The inlet section of the secondary pump tube 10 houses the secondary piston 9, which is positioned in front of the secondary diaphragm 801. The inlet section of the launch tube 13 houses the projectile 12, which is positioned in front of the tertiary diaphragm 1101.

[0174] The primary air chamber 101 is filled with high-pressure gas. Light gas is also filled in the primary gas pump tube 103, primary electromagnetic pump tube 501, primary high-pressure pump tube 7, and secondary air chamber 802 in front of the primary piston 3. The secondary pump tube 10 and tertiary air chamber 1102 in front of the secondary piston 9 are also filled with light gas. The launch tube 13, expansion tank 14, and test chamber 15 in front of the projectile 12 are also filled with test gas.

[0175] The primary air chamber 101 releases high-pressure gas, driving the armature 2 and primary piston 3 forward and out of the primary gas pump tube 103. The electromagnetic catapult 5 generates pulsed current and a pulsed magnetic field through discharges in the multi-stage drive coil 502. Under the combined action of the high-pressure gas thrust and electromagnetic force, the armature 2 propels the primary piston 3 forward within the primary electromagnetic pump tube 501. The primary piston 3 accelerates in the primary electromagnetic pump tube 502, decelerates in the primary high-pressure pump tube 7, and finally stops in the secondary air chamber 802. The light gas within the primary electromagnetic pump tube 501, primary high-pressure pump tube 7, and secondary air chamber 802 increases in pressure under the compression of the primary piston 3. Once it reaches a predetermined pressure, it breaks through the secondary diaphragm 801, pushing the secondary piston 9 forward within the secondary pump tube 10. The light gas within the secondary pump tube 10 and tertiary air chamber 1102, compressed by the secondary piston 9, reaches a high-temperature and high-pressure state. At this predetermined pressure, it breaks through the tertiary diaphragm 1101, propelling the projectile 12 at high speed out of the launch tube 13. The projectile 12 passes through the expansion tank 14 and enters the test chamber 15.

[0176] In one embodiment, the primary air chamber 101 includes a release mechanism, which is a piston-type release mechanism or a double-diaphragm release mechanism, which serves to isolate the gas and quickly open.

[0177] In one embodiment, the high-pressure gas filled in the primary gas chamber 101 is high-pressure air, high-pressure nitrogen, or high-pressure helium, and the pressure of the high-pressure gas is no more than 30 MPa.

[0178] In one embodiment, the light gas filled in the first-level gas pump tube 103 in front of the first-level piston 3, the first-level electromagnetic pump tube 501, the first-level high-pressure pump tube 7 and the second-level air chamber 802 and the second-level pump tube 10 and the third-level air chamber 1102 in front of the second-level piston 9 is hydrogen or helium, and the pressure of hydrogen or helium is 0.01~1.0MPa.

[0179] In one embodiment, the launch tube 13 in front of the projectile 12, the expansion tank 14 and the test chamber 15 are filled with a test gas which is air, and the air pressure is 10Pa to 0.2MPa.

[0180] In one embodiment, the ratio of the volume of the primary gas pump tube 103 to the volume of the primary gas chamber 101 is ≥1.0.

[0181] In one embodiment, the primary gas pump tube 103, the primary electromagnetic pump tube 501, and the primary high-pressure pump tube 7 are coaxial with each other and have the same inner diameter, which is not less than 50 mm.

[0182] In one embodiment, after the gas in the first-stage air chamber 101 is released, it pushes the armature 2 and the first-stage piston 3 to move in an isentropic expansion mode. The total pressure of the gas in the first-stage air chamber 101 is P 1x and total temperature T 1x The expression is:

[0183]

[0184]

[0185] Among them, γ1 is the specific heat ratio of high-pressure gas, P 10 is the initial pressure of the high-pressure gas in the first-stage gas chamber, T 10 is the initial temperature of the high-pressure gas in the first-stage gas chamber, V 10 is the initial volume of high-pressure gas in the first-stage gas chamber 101, x is the distance moved by the armature 2, D is the inner diameter of the electromagnetic pump tube, V 1x (x) is the volume of high pressure gas when the armature 2 moves a distance x.

[0186] In one embodiment, the first-stage piston 3 compresses the light gas in a near isentropic compression mode; the ratio of the mass of the first-stage piston 3 to the cross-sectional area of ​​the first-stage high-pressure pump pipe 7 is greater than 500 kg / m 2 .

[0187] In one embodiment, the total pressure of the light gas in the secondary gas chamber 802 before the secondary diaphragm 801 ruptures is P 2x and total temperature T 2x The expression is:

[0188]

[0189] Wherein, γ2 is the initial specific heat ratio of the light gas in the secondary gas chamber 802, P 20 is the initial pressure of the light gas in the secondary gas chamber 802, T 20 is the initial temperature of the light gas in the secondary gas chamber 802, V 20 is the initial total volume of the primary gas pump tube 103, the primary electromagnetic pump tube 501, the primary high-pressure pump tube 7, and the secondary air chamber 802 in front of the primary piston 3, x is the movement distance of the primary piston 3, D is the inner diameter of the primary electromagnetic pump tube 501, and V 2x (x) is the volume of light gas in the closed space between the primary piston 3 and the secondary diaphragm 801 when the primary piston 3 moves a distance x.

[0190] In one embodiment, the secondary diaphragm 801 adopts a flat plate structure and is provided with a "cross"-shaped four-petal groove or an "*"-shaped six-petal groove; the secondary diaphragm material is austenitic stainless steel with a tensile strength greater than 500 MPa.

[0191] In one embodiment, the first-level gas pump tube 103, the first-level high-pressure pump tube 7, the second-level pump tube 10, and the launch tube 13 are made of metal materials, preferably gun steel materials.

[0192] In one embodiment, the inner wall roughness of the first-level gas pump tube 103, the first-level electromagnetic pump tube 501, and the first-level high-pressure pump tube 7 is Ra≤1.6.

[0193] In one embodiment, the first-stage electromagnetic pump tube 501 is made of insulating material, preferably a high-strength resin-based composite material or a high-strength ceramic material, and the maximum operating temperature can reach 260 degrees Celsius.

[0194] In one embodiment, the ratio of the length to the inner diameter of the secondary pump tube 10 is 190-230.

[0195] In one embodiment, the ratio of the length to the inner diameter of the launch tube 13 is 280-420.

[0196] In one embodiment, the ratio of the inner diameters of the primary high-pressure pump tube 7 to the secondary pump tube 10 is 2.1 to 2.4.

[0197] In one embodiment, the ratio of the inner diameter of the secondary pump tube 10 to the inner diameter of the launch tube 13 is 3.5 to 4.5.

[0198] In one embodiment, the inner wall roughness of the secondary pump tube 10 and the launch tube 13 is Ra≤0.8.

[0199] In one embodiment, the number of drive coils 502 of the electromagnetic catapult device 5 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, electric energy-kinetic energy conversion efficiency, and expected total energy are reasonably estimated. In addition, the single-stage drive coil and the excitation power supply limit parameter conditions (voltage resistance, current resistance, stress, temperature rise, equipment cost, etc.) are combined and considered to determine a reasonable number of drive coils 502 stages to facilitate efficient and safe acceleration of the armature 2 and the first-stage piston 3. If the number of drive coils 502 stages is too small, the single-stage energy is too large, affecting the safety, technical difficulty, and cost of the drive coils 502 and the excitation power supply 505. If the number of drive coils 502 stages 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.

[0200] In one embodiment, the ratio of the length of each drive coil 502 to the inner diameter of the first electromagnetic pump tube 501 is 0.4 to 1.7, and the ratio of the distance between the facing end faces of adjacent drive coils 502 to the inner diameter of the first electromagnetic pump tube 501 is 0.1 to 0.3. By properly setting the length of the drive coil 502, the mutual inductance gradient and overall driving capacity between the drive coil 502 and the armature 2 are kept within a reasonable range.

[0201] In one embodiment, 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 an insulating material.

[0202] In one embodiment, the entire exterior of the multi-stage drive coil is covered by a metal layer 503 , which acts as an electromagnetic shield and structurally strengthens the primary electromagnetic pump tube 501 and the multi-stage drive coil.

[0203] The electromagnetic catapult 5 comprises a first-stage electromagnetic pump tube 501, n-stage (n greater than or equal to 3) drive coils 502 wound around the first-stage electromagnetic pump tube 501, a metal layer 503, an excitation power supply 505 for powering the drive coils 502, and a charger 504 for charging the excitation power supply 505. The conductors of the electromagnetic catapult drive coils 502 are wound with copper flat strip or copper tube. The conductors are coated with a composite material made of high-strength fibers such as glass fiber, Kevlar, and Chailong, and epoxy resin. The metal layer coats the entire multi-stage drive coils, providing electromagnetic shielding and structural reinforcement for the launch tube and multi-stage drive coils.

[0204] In one embodiment, Figure 2 As shown, each stage of the drive coil 502 is connected to an independent excitation power supply 505, which includes an energy storage pulse capacitor bank 50501, a main switch 50502, and a freewheeling switch 50503. The energy storage pulse capacitor bank 50501 can be connected in series with the main switch 50502 and in parallel with the freewheeling switch 50503 at both ends of the drive coil 502. The two ends of the energy storage pulse capacitor bank 50501 are also connected to the two ends of the charger 504 via a charging switch 50401.

[0205] 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.

[0206] The excitation power supply 505 is controlled by a timing trigger method through the measurement and control system 16 to achieve step-by-step discharge of the excitation power supply 505. The measurement and control system 16 monitors the voltage information of the excitation power supply 505, the current information of the drive coil 502, the pressure and temperature information of the high-pressure gas, light gas, and test gas, the motion information of the armature 2, the first-stage piston 3, and the second-stage piston 9, the motion information of the launch tube 13, the expansion tank 14, and the projectile in the test chamber 15, and the aerodynamic / thermal information, aerodynamic physical information, or high-speed collision information of the projectile in the test chamber 15 through sensors.

[0207] The measurement and control system 16 includes a central controller 1601, a pulse trigger circuit 1602, and an armature speed measuring device 1603. The central controller 1601 is preferably a digital signal processor (DSP) or a field programmable gate array (FPGA). The armature speed measuring device 1603 includes a photoelectric sensor body 160301 and photoelectric probes 160302. Multiple photoelectric probes 160302 of the armature speed measuring device 1603 are installed at intervals along the armature's motion direction on the walls of the primary gas pump tube 103 and the primary electromagnetic pump tube 501. The photoelectric sensor body 160301 and the photoelectric probes 160302 are connected via optical fibers. The photoelectric probes 160302 of the armature speed measuring device 1603 can emit pulsed light signals of a certain frequency to the armature through holes in the walls of the primary gas pump tube 103 and the primary electromagnetic pump tube 501, receive light signals reflected from the self-reflective light ring, convert the light signals into electrical signals, and transmit them to the central controller.

[0208] The central controller 1601 processes the electrical signal to determine the moment and speed of the armature 2 (specifically, the area at or near the rear end face of the armature 2, with rear referring to the direction of the armature 2 away from the piston 3) passing through the photoelectric probe 160302. Using a sequential trigger control method, the central controller calculates the expected triggering time for the stage to be triggered, or retrieves the expected triggering time from a pre-stored data table. At the expected triggering time, the central controller sends a trigger control signal to the pulse trigger circuit 1602, which outputs a power pulse to turn on the main switch 50502 of the next-stage excitation power supply, discharging the energy-storage pulse capacitor bank 50501 through the drive coil 502. When the voltage of the energy-storage pulse capacitor bank 50501 drops to zero, the freewheeling switch 50503 turns on, the main switch 50502 turns off, and the drive coil 502 continues to flow through the freewheeling switch 50503 until the discharge current drops to zero. Each stage of the excitation power supply operates in a similar manner.

[0209] like Figure 3 As shown, at least m photoelectric probes are evenly arranged axially backward from the center line of the first-stage driving coil. The first photoelectric sensor G f1 The axial distance between the center line of the first-stage driving coil is h / 2, and the axial distance between adjacent photoelectric probes is h.

[0210] v za is the speed 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 distance between the center lines of adjacent drive coils, and t m It is the time interval when the discharge current of the driving coil rises from zero to the maximum value. In some embodiments, t m Can be based on OK, Ld It is the sum of all self-inductances of the discharge circuit before the discharge current of the driving coil is freewheeled by the diode, and C is the capacitance value of the energy storage capacitor group.

[0211] At least n photoelectric probes G are evenly arranged axially forward from the center line of the first-stage driving coil. z1 , G z2 ,…,G zj , G zj+1 ,…,G zn-1 , G zn , the first photoelectric sensor G z1 Located on the pipe wall between the first and second stage drive coils, the first photoelectric sensor G z1 The distance from the center line of the first stage driving coil is the same as the first photoelectric probe G z1 The distance between the adjacent photoelectric probes is h.

[0212] The timing trigger control method executed by the central controller may be specifically as follows.

[0213] Step 1: Before the test, the armature 2 and primary piston 3 are positioned appropriately within the rear end of the primary gas pump tube 103, near the outlet of the primary air chamber 101. First, the exhaust valve 10110 of the primary air chamber 101 is opened, and the armature speed measuring device 1603 is controlled to emit a light signal into the tube at an appropriate frequency. The primary air chamber 101 releases high-pressure gas, driving the armature 2. This in turn pushes the primary piston 3 forward within the primary gas pump tube 103, causing the speed of the armature 2 and primary piston 3 to continuously increase.

[0214] 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. Repeat the following steps 2-1 and 2-2 until the first stage excitation power supply is triggered:

[0215] 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 1603 performs measurement, and the central controller 1601 performs signal processing to obtain the armature 2 speed v at this moment and this position fi ;

[0216] Step 2-2:

[0217] if Then the first stage excitation power supply is triggered after the delay time Δt1, and the delay time Δt1 satisfies: Let s = s + 1, let i = i - 1, jump out of this loop and execute step 3;

[0218] if Then no excitation power supply is to be triggered, and i=i-1;

[0219] When i=1, jump out of this loop, set s=s+1, and execute step 3.

[0220] Step 3: Repeat the steps 3-1 and 3-2 until the armature 2 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.

[0221] Step 3-1: When the armature 2 moves to 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 s-stage drive coil is l fis =(i+s-3 / 2)h, the armature speed measuring device 1603 performs measurement, and the central controller 1601 performs signal processing to obtain the armature 2 speed v at this moment and this position fi .

[0222] Step 3-2:

[0223] if Then the s-th level excitation power supply is triggered immediately, let s = s + 1, let i = i - 1;

[0224] if Then at the delay time Δt s Then trigger the s-th level excitation power supply, delay time Δt s satisfy: Let s = s + 1, let i = i - 1;

[0225] if Then no excitation power supply is to be triggered, and i=i-1.

[0226] Step 4: When the armature 2 passes through the center line of the first stage drive coil and moves to the first photoelectric probe G in front of the center line of the first stage drive coil z1 When the s-th level excitation power supply is triggered and turned on, this moment is t s , the distance between the center line of armature 2 and the first stage driving coil is x s =h / 2, the armature speed measuring device 1603 performs measurement, and the central controller 1601 performs signal processing to obtain t s At this moment, the speed of armature 2 is v s .

[0227] Step 5: Loop through the following steps 5-1, 5-2, and 5-3 until the moment t at which the n-th stage excitation power supply is turned on is obtained. n :

[0228] Step 5-1: At time t s+1Triggering the conduction of the s+1th level excitation power supply, time t s+1 satisfy:

[0229] v s is time t s Armature 2 speed, a is the average acceleration of armature 2, h is the center distance between two adjacent drive coils, t m It is the time interval from when the discharge current of the driving coil changes from zero to when it reaches the maximum value;

[0230] Step 5-2: The central controller 1601 calculates the time t s+1 The estimated speed of armature 2 is

[0231] This estimated speed is taken as the time t s+1 The approximate value of the actual speed of the armature 2 at the time t s+1 The approximate value of the distance between the center line of the armature 2 and the first stage drive coil is x s+1 =x s +h-at m (t s+1 -t s )<x s +h;

[0232] Step 5-3: Let s=s+1.

[0233] In some scenarios, the armature 2 passes the jth photoelectric probe G in front of the center line of the first stage drive coil. zj , j+1th photoelectric sensor G zj+1 The time and speed are t zj 、v zj and t zj+1 、v zj+1 , where armature 2 passes the first photoelectric probe G in front of the center line of the first stage drive coil z1 The time and speed are t z1 =t s 、v z1 =v s The central controller can calculate the j+1th photoelectric probe G in front of the center line of the first-stage drive coil when the armature 2 passes through. zj+ The estimated time and speed are

[0234] Photoelectric probe G z2 ,…,G zj , G zj+1 ,…,G zn-1 , G znIt can be used to measure the time and speed when the armature 2 passes the corresponding position, and compare it with the time and speed predicted values ​​calculated by the central controller 1601, so as to facilitate the monitoring and analysis of the motion state of the armature 2 and the timing trigger control effect, but it does not need to participate in the dynamic control of the timing trigger.

[0235] Furthermore, the energy storage pulse capacitor group 50501 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.

[0236] Furthermore, the main switch 50502 is a spark gap switch or a high-voltage switch composed of a semiconductor thyristor.

[0237] Furthermore, the freewheeling switch 50503 is composed of a combination of semiconductor high-voltage diodes.

[0238] like Figure 2 As shown, the measurement and control system 16 may further include an excitation power supply voltage measuring device 1604 and a drive coil current measuring device 1605. The excitation power supply voltage measuring device 1604 may be used to monitor the voltage of the energy storage pulse capacitor bank 50501. The drive coil current measuring device 1605 may be used to monitor the current of the drive coil 502.

[0239] First stage gas propulsion section 1 embodiment:

[0240] like Figure 4As shown, the primary gas propulsion section 1 comprises a primary air chamber 101, a connection mechanism A102 between the primary air chamber 101 and the primary gas pump tube, and a primary gas pump tube 103. The primary air chamber 101 is connected to the primary gas pump tube 103 via the connection mechanism A102. The primary air chamber 101 includes a piston-type release mechanism. Its principle is as follows: high-pressure gas enters the exhaust chamber 10102 through the inlet valve 10109. The pressure in the exhaust chamber 10102 continues to rise, causing the valve body piston to move rightward, compressing the spring 10107 and ultimately pressing the valve body against the inlet of the primary air chamber 101. Simultaneously, the one-way valve 10105 opens, allowing high-pressure gas from the exhaust chamber 10102 to enter the primary air chamber inner chamber 10101. Once the pressure reaches a predetermined level, the inlet valve 10109 closes. To release the pressure, the exhaust valve 10110 opens, rapidly discharging the high-pressure gas in the exhaust chamber 10102. Simultaneously, 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 spring 10107, valve body 10108 moves rapidly to the left, leaving the entrance of the primary air chamber 101. The high-pressure gas in the inner cavity 10101 of the primary air chamber immediately enters the primary gas barrel 103, driving the armature 2 and thus pushing the primary piston 3 forward within the primary 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, preventing the valve body 10108 from directly colliding with the release mechanism.

[0241] Example of the connection mechanism A102 between the first-stage gas chamber 101 and the first-stage gas pump tube 103:

[0242] like Figure 5 As shown, the inlet of the primary air chamber 101 is connected to the inlet of the primary gas pump pipe 103 via a connection mechanism A102. A concave stopper is provided at the inlet of the primary air chamber 101, while a convex stopper is provided at the left end of the primary gas pump pipe 103. Connection mechanism A102 comprises a steel flange pipe fitting Aa10201, a steel flange pipe fitting Ab10202, and a steel bolt assembly Ac10203. The steel flange pipe fittings Aa10201 and Ab10202 are respectively secured to the outer surfaces of the inlet of the primary air chamber 101 and the inlet of the gas pump pipe 103 by threads or welding. The steel flange pipe fittings Aa10201 and Ab10202 are connected and secured by the steel bolt assembly Ac10203.

[0243] Example of connection between segments of the primary gas pump pipe 103:

[0244] like Figure 6As shown, the first-level gas pump pipe section k 10301 and the first-level gas pump pipe section k+1 are adjacent to each other, the first-level gas pump pipe section k 10301 has a concave stop at the right end, and the first-level gas pump pipe section k+1 10302 has a convex stop at the left end, and the two are connected and fastened by a steel half nut assembly 104.

[0245] Example of connecting the primary gas pump tube 103 and the primary electromagnetic pump tube 501:

[0246] like Figure 7 As shown, the first-level gas pump pipe 103 has the same inner diameter as the first-level electromagnetic pump pipe 501. The first-level gas pump pipe 103 is a steel pipe with a relatively large wall thickness, while the first-level electromagnetic pump pipe 501 is an insulating pipe with a relatively small wall thickness. The first-level gas pump pipe 103 is connected to the first-level electromagnetic pump pipe 501 via a connecting mechanism B4. The connecting mechanism B4 includes a steel flange pipe fitting Ba401, an insulating flange pipe fitting Bb402, and a bolt assembly Bc403. The steel flange pipe fitting Ba401 is fixed to the outer surface of the outlet end of the first-level gas pump pipe 103 by threading or welding, and the insulating flange pipe fitting Bb402 is fixed to the outer surface of the inlet end of the first-level electromagnetic pump pipe 501 by bonding. The steel flange pipe fitting Ba401 and the insulating flange pipe fitting Bb402 are connected and tightened by the bolt assembly Bc403.

[0247] Example of connection between segments of the first-stage electromagnetic pump pipe 501:

[0248] like Figure 8 As shown, the first-stage electromagnetic pump pipe section k 50101 and the first-stage electromagnetic pump pipe section k+1 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 to the outer surface of the left end of the first-stage electromagnetic pump pipe section k 50101 and the outer surface of the right end of the first-stage electromagnetic pump pipe section k+1 50102. The two are connected and tightened by an insulating bolt assembly Cc50603.

[0249] Example of connecting the first-level electromagnetic pump tube 501 with the first-level high-pressure pump tube 7:

[0250] like Figure 9As shown, the first-stage electromagnetic pump pipe 501 and the first-stage high-pressure pump pipe 7 have the same inner diameter. Typically, the first-stage electromagnetic pump pipe 501 is an insulating pipe with a relatively thin wall thickness, while the first-stage high-pressure pump pipe 7 is a steel pipe with a relatively thick wall thickness. The first-stage electromagnetic pump pipe 501 is connected to the first-stage high-pressure pump pipe 7 via a connection mechanism D6. Connection mechanism D6 includes an insulating flange pipe fitting Da601, a steel flange pipe fitting Db602, and a bolt assembly Dc603. The insulating flange pipe fitting Da601 is fixed to the outer surface of the outlet end of the first-stage electromagnetic pump pipe 501 by bonding, and the steel flange pipe fitting Db602 is fixed to the outer surface of the inlet end of the first-stage high-pressure pump pipe 7 by threading or welding. The insulating flange pipe fitting Da601 and the steel flange pipe fitting Db602 are connected and tightened by the bolt assembly Dc603.

[0251] Example of connection between 7 sections of the first-level high-pressure pump pipe:

[0252] like Figure 10 As shown, the first-level high-pressure pump pipe section k 701 and the first-level high-pressure pump pipe section k+1 702 are adjacent, and the concave stop provided at the right end of the first-level high-pressure pump pipe section k 701 is adapted to the convex stop provided at the left end of the first-level high-pressure pump pipe section k+1 702; the steel flange pipe fitting Ea70301 and the steel flange pipe fitting Eb70302 are respectively fixed to the outer surface of the right end of the first-level high-pressure pump pipe section k 701 and the outer surface of the left end of the first-level high-pressure pump pipe section k+1 702 by threads or welding, and the two are connected and fastened by a steel bolt assembly Ec70303.

[0253] Example of connection between the primary high-pressure pump pipe 7 and the secondary pump pipe 10:

[0254] like Figure 11 As shown, in one embodiment, the secondary air chamber 802 includes a first large-diameter straight pipe section, a first diameter-reducing section and a first small-diameter straight pipe section, the first large-diameter straight pipe section and the first small-diameter straight pipe section are respectively provided with convex stoppers, and the cone angle of the first diameter-reducing section is 5° to 10°; the tertiary air chamber 1102 includes a second large-diameter straight pipe section, a second diameter-reducing section and a second small-diameter straight pipe section, the second large-diameter straight pipe section and the second small-diameter straight pipe section are respectively provided with convex stoppers, and the cone angle of the second diameter-reducing section is 10° to 20°.

[0255] In some embodiments, the ratio of the length of the first large-diameter straight pipe section to the first variable-diameter section is 0.4 to 0.8, the ratio of the length of the first small-diameter straight pipe section to the first variable-diameter section is 0.2 to 0.5, and the ratio of the length of the first-stage high-pressure pump tube 7 to the first variable-diameter section of the secondary air chamber 802 is 3 to 10.

[0256] In some embodiments, the inner wall roughness of the tertiary air chamber 1102 is Ra≤0.8; the length ratio of the second large diameter straight pipe section to the second reduced diameter section of the tertiary air chamber 1102 is 0.5-1.0, and the length ratio of the second small diameter straight pipe section to the second reduced diameter section is 0.3-0.6.

[0257] like Figure 11 As shown, in one embodiment, a concave stop is provided at the outlet end of the first-level high-pressure pump tube 7, and the concave stop is adapted to the convex stop of the first large-diameter straight pipe section of the secondary air chamber 802; a concave stop, a secondary diaphragm groove, and a first conical groove are provided in sequence at the inlet end of the secondary pump tube 10 along the center line, and the concave stop is adapted to the convex stop of the first small-diameter straight pipe section of the secondary air chamber 802, and the diameter of the concave stop is larger than the secondary diaphragm groove, and the secondary diaphragm 801 is placed in the secondary diaphragm groove; the diameter of the first conical groove gradually decreases from one end of the diaphragm groove, the maximum diameter of the first conical groove is smaller than the diameter of the secondary diaphragm groove, and the minimum diameter of the first conical groove is equal to the inner diameter of the secondary pump tube 10.

[0258] Example of connecting the two-stage pump pipe 10 segments:

[0259] like Figure 12 As shown, the secondary pump pipe section k 1001 and the secondary pump pipe section k+1 1002 are adjacent, and the concave stop provided at the right end of the secondary pump pipe section k 1001 is adapted to the convex stop provided at the left end of the secondary pump pipe section k+1 1002; the steel flange pipe fitting Ga100301 and the steel flange pipe fitting Gb100302 are respectively fixed to the outer surface of the right end of the secondary pump pipe section k 1001 and the outer surface of the left end of the secondary pump pipe section k+1 1002 by threads or welding, and the two are connected and fastened by a steel bolt assembly Gc100303.

[0260] Secondary pump tube 10 and launch tube 13 connection embodiment:

[0261] like Figure 13 As shown, further, a concave stop is provided at the outlet end of the secondary pump tube 10, and the concave stop is adapted to the convex stop of the second large-diameter straight pipe section of the tertiary air chamber 1102; a concave stop, a tertiary diaphragm groove, and a second conical groove are provided in sequence at the inlet end of the launch tube 13 along the center line, and the concave stop is adapted to the convex stop of the second small-diameter straight pipe section of the tertiary air chamber 1102, and the diameter of the concave stop is larger than the tertiary diaphragm groove, and the tertiary diaphragm 1101 is placed in the tertiary diaphragm groove; the diameter of the second conical groove gradually decreases from one end of the diaphragm groove, the maximum diameter of the second conical groove is smaller than the diameter of the tertiary diaphragm groove, and the minimum diameter of the second conical groove is equal to the inner diameter of the launch tube 13.

[0262] Example of connection between segments of launch tube 13:

[0263] like Figure 14As shown, the launch tube section k 1301 and the launch tube section k+1 1302 are adjacent to each other, and the concave stop provided at the right end of the launch tube section k 1301 is adapted to the convex stop provided at the left end of the launch tube section k+1 1302; the steel flange pipe fitting Ja 130301 and the steel flange pipe fitting Jb 130302 are respectively fixed to the outer surface of the right end of the launch tube section k 1301 and the outer surface of the left end of the launch tube section k+1 1302 by threads or welding, and the two are connected and fastened by a steel bolt assembly Jc 130303.

[0264] 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.

[0265] In one embodiment, the structure of the first-stage piston 3 or the second-stage piston 9 is an integral cylindrical structure or a three-section structure in which the piston head, steel counterweight, and piston tail are connected in sequence as one body. The piston head and piston tail of the first-stage piston 3 or the second-stage piston 9 are made of polyethylene or polytetrafluoroethylene.

[0266] In one embodiment, the secondary diaphragm 801 or the tertiary diaphragm 1101 adopts a flat plate structure and is provided with a "cross" or "*" shaped groove. The secondary diaphragm 801 or the tertiary diaphragm 1101 is made of stainless steel or aluminum alloy.

[0267] In one embodiment, the projectile 12 is a full-caliber projectile without a buttress or a combination projectile with a buttress; when the projectile 12 is a full-caliber projectile without a buttress, the ratio of the length to the diameter of the projectile 12 is greater than 0.5, and after the projectile 12 is fired, it passes through the expansion box 14 and enters the test chamber 15; when the projectile 12 is a combination projectile with a buttress, the combination projectile consists of a projectile body and a buttress, and the buttress is a split-petal combination structure with two to eight petals, and the buttress material is polycarbonate or high-pressure polyethylene or nylon. After the projectile 12 is fired, the buttress and the projectile body are separated in the expansion box 14, and the projectile body enters the test chamber 15.

[0268] In one embodiment, the expansion tank 14 and the test chamber 15 are equipped with a projectile velocity measurement system, a camera system for measuring the projectile position and posture, a shadow / schlieren device for displaying the flow field, and a light radiation measurement system for measuring light radiation characteristics.

[0269] Expansion tank 14, test chamber 15 and related measurement and control device embodiments:

[0270] like Figure 15As shown, the expansion tank 14 and the test chamber 15 are filled with air at a pressure range of 10 Pa to 0.2 MPa. The expansion tank 14 is provided with a vacuum system interface 1401, multiple side optical windows 1402, and a top optical window 1403. Multiple expansion tank projectile velocity measuring devices 1606 are installed on the side. Multiple expansion tank binocular vision measurement systems 1607 for measuring the dynamic process of separation between the combined projectile sabot and the projectile body are installed on the side and top. The test chamber 15 is provided with a vacuum system interface 1501, multiple side optical windows 1502, and a top optical window 1503. Multiple test chamber projectile velocity measuring devices 1608, a flow field display schlieren instrument 1609, and an optical radiation measurement system 1611 for measuring optical radiation characteristics are installed on the side. A binocular vision measurement system 1610 for measuring the projectile flight attitude is installed on the side and top.

[0271] In one embodiment, the ballistic target includes several supporting mechanisms 17 and a track system 18. The supporting mechanisms 17 are respectively located below the first-level air chamber 101, the first-level gas pump tube 103, the first-level electromagnetic pump tube 501, the first-level high-pressure pump tube 7, the second-level pump tube 10, the launch tube 13, the expansion tank 14 and the test chamber 15. The supporting mechanisms 17 are installed on the track system 18 and can move along the track.

[0272] The working principle of the present invention is as follows:

[0273] Before the test, the armature 2 and the piston 3 are placed at appropriate positions in the inlet end of the first-stage gas pump tube 103, with the armature 2 behind the first-stage piston 3; the second-stage piston 9 is placed in the inlet section of the second-stage pump tube 10 and in front of the second-stage diaphragm 801; the projectile 12 is placed in the inlet section of the launch tube 13 and in front of the third-stage diaphragm 1101; the first-stage gas pump tube 103, the first-stage electromagnetic pump tube 501, the first-stage high-pressure pump tube 7 and the second-stage air chamber 802 in front of the first-stage piston 3 and the second-stage pump tube 10 and the third-stage air chamber 1102 in front of the second-stage piston 9 are filled with 0.01 to 1.0 MPa of hydrogen or helium; the launch tube 13, the expansion tank 14 and the test chamber 15 in front of the projectile 12 are filled with 10 Pa to 0.2 MPa of air; and the energy storage pulse capacitor groups 50501 at each level are charged to the set voltage.

[0274] During the test, the exhaust valve 10110 of the first-stage air chamber 101 is first opened. Simultaneously, the armature speed measuring device 1603 is controlled to emit a light signal at an appropriate frequency into the first-stage gas pump tube 103. The high-pressure gas released from the first-stage air chamber 101 drives the armature 2, which pushes the first-stage piston 3 forward within the first-stage gas pump tube 103. The speeds of the armature 2 and the first-stage piston 3 continuously increase. When the armature 2 passes the mth photoelectric probe behind the centerline of the first-stage drive coil, the armature 2 has a certain initial velocity. The armature speed measuring device 1603 performs measurement, and the central controller 1601 performs signal processing. The steps of the sequential trigger control method are then repeatedly executed to calculate the expected trigger time of the first stage. At the expected triggering time of the first stage, central controller 1601 sends a trigger control signal to pulse trigger circuit 1602. Pulse trigger circuit 1602 outputs a power pulse to turn on the first-stage excitation power supply main switch 50502, causing the first-stage energy storage pulse capacitor bank 50501 to discharge through the first-stage drive coil 502. After the voltage of the energy storage pulse capacitor bank 50501 drops to zero, the drive coil 502 continues to flow through the freewheeling switch 50503. The pulse current excites a pulse magnetic field, generating eddy currents in the armature 2 and subjecting it to electromagnetic force. After the first stage is triggered, the armature 2 pushes the first-stage piston 3 forward under the combined action of gas thrust and the electromagnetic force of the first-stage drive coil. Continuing with the relevant steps of the sequential triggering control method, after triggering several stages of the excitation power supply, the armature 2 moves under the combined action of gas thrust and the electromagnetic force of several stages of the discharged drive coils, passing the first photoelectric sensor behind the centerline of the first-stage drive coil and passing through the centerline of the first-stage drive coil. At time t s , the armature 2 moves to the first photoelectric probe in front of the center line of the first-stage drive coil, triggering the conduction of the s-stage excitation power supply, and the speed of the armature 2 at this moment is measured. s Time t s After that, the armature 2 basically moves at a constant acceleration. The s+1th stage excitation power supply is triggered and the steps of the sequential trigger control method are executed repeatedly until the nth stage excitation power supply is turned on. During uniform acceleration, the armature 2 propels the first-stage piston 3 forward under the combined action of electromagnetic force, gas thrust at the rear end, and light gas resistance at the front end. The armature 2 then flies out of the first-stage electromagnetic pump tube 501 at high speed and enters the first-stage high-pressure pump tube 7. The first-stage piston 3 decelerates in the first-stage high-pressure pump tube 7 and decelerates to a final stop in the second-stage air chamber 802. During this process, the light gas in the first-stage electromagnetic pump tube 501, the first-stage high-pressure pump tube 7 and the second-stage air chamber 802 increases in pressure under the compression of the first-stage piston 3, and breaks through the second-stage diaphragm 801 after reaching the rupture pressure of the second-stage diaphragm 801, pushing the second-stage piston 9 to move forward in the second-stage pump tube 10; the light gas in the second-stage pump tube 10 and the third-stage air chamber 1102 increases in temperature and pressure under the compression of the second-stage piston 9, and the high-temperature and high-pressure light gas in the third-stage air chamber 1102 reaches the rupture pressure of the third-stage diaphragm 1101 and then breaks through the third-stage diaphragm 1101, pushing the projectile 12 to be launched out of the launch tube 13 at high speed. When the projectile 12 is a full-caliber projectile without a sabot, it passes through the expansion box 14 and enters the test chamber 15 after being fired; when the projectile 12 is a combined projectile with a sabot, the sabot and the projectile body are separated in the expansion box 14, and the projectile body enters the test chamber 15.

[0275] 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 ballistic target based on a three-stage light gas gun driven by electromagnetic catapult, characterized in that: The invention comprises a first-stage gas propulsion section (1), an electromagnetic ejection device (5), an armature (2), a first-stage piston (3), a first-stage high-pressure pump pipe (7), a first-stage and second-stage connecting mechanism (8), a second-stage pump pipe (10), a second-stage piston (9), a second-stage and third-stage connecting mechanism (11), a projectile (12), a launch tube (13), an expansion tank (14), a test chamber (15) and a measurement and control system (16); wherein, The first-stage gas propulsion section (1) comprises a first-stage gas chamber (101) and a first-stage gas pump pipe (103); The electromagnetic ejection device (5) comprises a primary electromagnetic pump tube (501), a multi-stage drive coil (502) wound on the primary electromagnetic pump 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 first and second level connection mechanism (8) includes a second level air chamber (802) and a second level diaphragm (801); the second and third level connection mechanism (11) includes a third level air chamber (1102) and a third level diaphragm (1101); the first level gas pump pipe (103), the first level electromagnetic pump pipe (501), the first level high pressure pump pipe (7), and the second level air chamber (802) are connected in sequence; the second level air chamber (802) is connected to the second level pump pipe (10) with the second level diaphragm (801) provided therebetween; the second level pump pipe (10) is connected to the third level air chamber (1102); the third level air chamber (1102) is connected to the launch tube (13) with the third level diaphragm (1101) provided therebetween; the launch tube (13) is connected to the expansion tank (14) and the test chamber (15) in sequence; The inlet section of the first-stage gas pump tube (103) is equipped with an armature (2) and a first-stage piston (3), the armature (2) is located behind the first-stage piston (3), the inlet section of the second-stage pump tube (10) is equipped with a second-stage piston (9), the second-stage piston (9) is located in front of the second-stage diaphragm (801), and the inlet section of the launch tube (13) is equipped with a projectile (12), the projectile (12) is located in front of the third-stage diaphragm (1101); The first-stage air chamber (101) releases high-pressure gas, driving the armature (2) and the first-stage piston (3) to move forward and fly out of the first-stage gas pump pipe (103); The electromagnetic ejection device (5) generates pulse current and pulse magnetic field through discharge of a multi-stage driving coil (502); The excitation power supply (505) is triggered step by step to discharge the multi-stage drive coil (502) step by step, and the armature (2) moves under the combined action of the gas thrust and the electromagnetic force generated by the multi-stage drive coil (502) and pushes the first-stage piston (3), and the first-stage piston (3) flies out of the electromagnetic pump pipe and enters the first-stage high-pressure pump pipe (7); The first-stage gas pump tube (103), the first-stage electromagnetic pump tube (501), the first-stage high-pressure pump tube (7) and the second-stage air chamber (802) in front of the first-stage piston (3) are filled with light gas. The light gas in the first-stage gas pump tube (103), the first-stage electromagnetic pump tube (501), the first-stage high-pressure pump tube (7) and the second-stage air chamber (802) breaks through the second-stage diaphragm (801) under the compression of the first-stage piston (3), thereby pushing the second-stage piston (9) to move forward in the second-stage pump tube (10); The secondary pump tube (10) and the tertiary air chamber (1102) in front of the secondary piston (9) are filled with light gas. The light gas in the secondary pump tube (10) and the tertiary air chamber (1102) breaks through the tertiary diaphragm (1101) under the compression of the secondary piston (9), driving the projectile (12) to fly out of the launch tube (13) and enter the test chamber (15) through the expansion box (14); The measurement and control system (16) is used to determine the triggering time of each level of the excitation power supply (505) according to the moving speed and position of the armature (2); The total pressure of gas in the first-stage gas chamber (101) is P 1x and total temperature T 1x The expression is: Among them, γ1 is the specific heat ratio of high-pressure gas, P 10 is the initial pressure of the gas in the first-stage gas chamber (101), T 10 is the initial temperature of the gas in the first-stage gas chamber (101), V 10 is the initial volume of gas in the first-stage gas chamber (101), x is the distance traveled by the armature (2), D is the inner diameter of the electromagnetic pump tube, V 1x (x) is the volume of gas when the armature (2) moves a distance x.

2. The ballistic target according to claim 1, wherein The first-stage gas propulsion section (1) satisfies at least one of the following: The gas in the primary gas chamber (101) is air, nitrogen or helium, and the gas pressure is no more than 30 MPa; The primary air chamber (101) is connected to the primary gas pump pipe (103) via a flange structure or an open sawtooth thread structure; the primary air chamber (101) includes 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 primary gas pump tube (103) to the volume of the primary gas chamber (101) is ≥1.0; The primary gas pump pipe (103) is made of gun steel; The inner wall roughness of the primary gas pump tube (103) is Ra≤1.

6.

3. The ballistic target according to claim 1, wherein The electromagnetic ejection device (5) satisfies at least one of the following conditions: The first-level electromagnetic pump tube (501) is made of a high-strength resin-based composite material or a high-strength ceramic material, and the maximum operating temperature can reach 260 degrees Celsius; The charger (504) is an IGBT series resonant constant current charging power supply; The inner wall roughness of the first-stage electromagnetic pump tube (501) is Ra≤1.6; The ratio of the length of each stage driving coil (502) of the electromagnetic ejection device (5) to the inner diameter of the first stage electromagnetic pump 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 first stage electromagnetic pump tube (501) is 0.1 to 0.

3.

4. The ballistic target according to claim 1, wherein 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) via 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 (16).

5. The ballistic target according to claim 4, wherein: 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, 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 (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, wherein The primary high-pressure pump pipe (7) satisfies at least one of the following: The ratio of the mass of the first-stage piston (3) to the cross-sectional area of ​​the first-stage high-pressure pump pipe (7) is greater than 500 kg / m 2 ; The first-level high-pressure pump pipe (7) is made of gun steel; The inner wall roughness of the first-level high-pressure pump pipe (7) is Ra≤1.

6.

7. The ballistic target according to claim 1, wherein The secondary air chamber (802) satisfies at least one of the following: The total pressure P of the light gas in the secondary air chamber (802) before the secondary diaphragm (801) ruptures 2x and total temperature T 2x The expression is: Wherein, γ2 is the initial specific heat ratio of the light gas in the secondary gas chamber (802), P 20 is the initial pressure of the light gas in the secondary gas chamber (802), T 20 is the initial temperature of the light gas in the secondary gas chamber (802), V 20 is the initial total volume of the first-stage gas pump tube (103), the first-stage electromagnetic pump tube (501), the first-stage high-pressure pump tube (7), and the second-stage air chamber (802) in front of the first-stage piston (3), x is the movement distance of the first-stage piston (3), D is the inner diameter of the first-stage electromagnetic pump tube (501), and V 2x (x) is the volume of light gas in the closed space between the first-stage piston (3) and the second-stage diaphragm (801) when the first-stage piston (3) moves a distance x; The secondary air chamber (802) comprises a first large-diameter straight pipe section, a first diameter-reducing section, and a first small-diameter straight pipe section; the length ratio of the first large-diameter straight pipe section to the first diameter-reducing section is 0.4 to 0.8, the length ratio of the first small-diameter straight pipe section to the first diameter-reducing section is 0.2 to 0.5, the first diameter-reducing section adopts a cone structure with a small cone angle of 5° to 10°, and the length ratio of the first high-pressure pump pipe (7) to the first diameter-reducing section of the secondary air chamber (802) is 3 to 10.

8. The ballistic target according to claim 1, wherein The secondary pump tube (10) satisfies at least one of the following: The secondary pump pipe (10) is made of gun steel; The ratio of the inner diameters of the first-stage high-pressure pump tube (7) and the second-stage pump tube (10) is 2.1 to 2.4; The ratio of the inner diameter of the secondary pump tube (10) to the inner diameter of the launch tube (13) is 3.5 to 4.5; The ratio of the length to the inner diameter of the secondary pump tube (10) is 190 to 230; The inner wall roughness of the secondary pump tube (10) is Ra≤0.

8.

9. The ballistic target according to claim 1, wherein The tertiary air chamber (1102) comprises a second large-diameter straight pipe section, a second reduced-diameter section, and a second small-diameter straight pipe section. The inner wall roughness of the tertiary air chamber (1102) is Ra≤0.8; the length ratio of the second large-diameter straight pipe section to the second reduced-diameter section of the tertiary air chamber (1102) is 0.5-1.0, and the length ratio of the second small-diameter straight pipe section to the second reduced-diameter section is 0.3-0.6; and the cone angle of the second reduced-diameter section of the tertiary air chamber (1102) is 10°-20°.

10. The ballistic target according to claim 1, wherein The transmitting tube (13) satisfies at least one of the following: The launch tube (13) is made of gun steel; The ratio of the length to the inner diameter of the launch tube (13) is 280 to 420; The inner wall roughness of the transmitting tube (13) is Ra≤0.

8.

11. The ballistic target according to claim 1, wherein The ballistic target satisfies at least one of the following: The first-level gas pump pipe (103), the first-level electromagnetic pump pipe (501), and the first-level high-pressure pump pipe (7) are coaxial with each other and have the same inner diameter, which is not less than 50 mm; The light gas filled in the first gas pump pipe (103) in front of the first piston (3), the first electromagnetic pump pipe (501), the first high-pressure pump pipe (7), the second air chamber (802), the second pump pipe (10) in front of the second piston (9), and the third air chamber (1102) is hydrogen or helium, and the pressure of the hydrogen or helium is 0.01-1.0 MPa; the test gas filled in the launch tube (13) in front of the projectile (12), the expansion box (14) and the test chamber (15) is air, and the air pressure is 10 Pa-0.2 MPa; The inlet end of the first-level electromagnetic pump pipe (501) is connected to the outlet end of the first-level gas pump pipe (103) via a flange structure; The outlet end of the first-level electromagnetic pump pipe (501) is connected to the inlet end of the first-level high-pressure pump pipe (7) via a flange structure; When the first-level gas pump pipe (103), the first-level electromagnetic pump pipe (501), the first-level high-pressure pump pipe (7), the second-level pump pipe (10), and the launch pipe (13) are connected to each other in sections of pipes of the same specifications, each section is connected by a flange structure, a half nut structure, or a half clamp structure; The first large-diameter straight pipe section and the first small-diameter straight pipe section of the secondary air chamber (802) are respectively provided with convex stoppers; the outlet end of the primary high-pressure pump pipe (7) is provided with a concave stopper; the inlet end of the secondary pump pipe (10) is provided with a concave stopper, a secondary diaphragm (801) groove, and a first conical groove in sequence along the center line, the concave stopper having a diameter greater than that of the secondary diaphragm (801) groove, and the secondary diaphragm (801) is placed in the secondary diaphragm (801) groove; the diameter of the first conical groove gradually decreases from one end of the diaphragm groove, the maximum diameter of the first conical groove is smaller than the diameter of the secondary diaphragm (801) groove, and the minimum diameter of the first conical groove is equal to the inner diameter of the secondary pump pipe (10); the convex stopper of the first large-diameter straight pipe section of the secondary air chamber (802) is adapted to the concave stopper of the outlet end of the primary high-pressure pump pipe (7); the convex stopper of the first small-diameter straight pipe section of the secondary air chamber (802) is adapted to the concave stopper of the inlet end of the secondary pump pipe (10); The second large-diameter straight pipe section and the second small-diameter straight pipe section of the three-stage air chamber (1102) are respectively provided with convex stoppers; the outlet end of the two-stage pump pipe (10) is provided with a concave stopper; the inlet end of the launch tube (13) is provided with a concave stopper, a three-stage diaphragm (1101) groove, and a second conical groove in sequence along the center line, the concave stopper having a diameter larger than the three-stage diaphragm (1101) groove, and the three-stage diaphragm (1101) is placed in the three-stage diaphragm (1101) groove; the second conical groove The diameter of the tapered groove gradually decreases from one end of the diaphragm groove, the maximum diameter of the second tapered groove is smaller than the diameter of the tertiary diaphragm (1101) groove, and the minimum diameter of the second tapered groove is equal to the inner diameter of the launch tube (13); the convex stop of the second large-diameter straight pipe section of the tertiary air chamber (1102) is adapted to the concave stop of the outlet end of the secondary pump pipe (10); the convex stop of the second small-diameter straight pipe section of the tertiary air chamber (1102) is adapted to the concave stop of the inlet end of the launch tube (13); 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 structure of the first-stage piston (3) or the second-stage piston (9) is an integral cylindrical type or a three-stage type in which a piston head, a steel counterweight, and a piston tail are sequentially connected as one body. The piston head and the piston tail of the first-stage piston (3) or the second-stage piston (9) are made of polyethylene or polytetrafluoroethylene. The secondary diaphragm (801) or the tertiary diaphragm (1101) adopts a flat plate structure and is provided with a "cross"-shaped four-petal groove or an "*"-shaped six-petal groove; the material of the secondary diaphragm (801) or the tertiary diaphragm (1101) is austenitic stainless steel or aluminum alloy with a tensile strength greater than 500 MPa; The projectile (12) is a full-caliber projectile (12) without a buttstock or a combined projectile (12) with a buttstock. When the projectile (12) is a full-caliber projectile (12) without a buttstock, the ratio of the length to the diameter of the projectile (12) is greater than 0.

5. After the projectile (12) is fired, it passes through an expansion box (14) and enters a test chamber (15). When the projectile (12) is a combined projectile (12) with a buttstock, the combined projectile (12) consists of a projectile (12) body and a buttstock. The buttstock is a split-petal combination structure with two to eight petals. The buttstock material is polycarbonate, high-pressure polyethylene, or nylon. After the projectile (12) is fired, the buttstock and the projectile (12) body are separated in the expansion box (14), and the projectile (12) body enters the test chamber (15). The expansion tank (14) and the test chamber (15) are equipped with a projectile (12) velocity measurement system, a camera system for measuring the position and posture of the projectile (12), a shadow / schlieren instrument for flow field display, 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 first-level gas chamber (101), the first-level gas pump pipe (103), the first-level electromagnetic pump pipe (501), the first-level high-pressure pump pipe (7), the second-level pump pipe (10), the launch tube (13), the expansion tank (14) and the test chamber (15). The supporting mechanisms are installed on the track system and can move along the track. The speed of the armature (2) at the center line of the first-stage driving coil (502) in the first-stage electromagnetic pump tube (501) is v za , the outlet velocity of the first-stage electromagnetic pump tube (501) is v zb , 0<v za <v zb ≤1000m / s.

12. The ballistic target according to claim 1, wherein The measurement and control system (16) includes a central controller (1601), a pulse trigger circuit (1602) and an armature speed measuring device (1603); The armature speed measuring device (1603) comprises a photoelectric sensor body (160301) and a plurality of photoelectric probes (160302), wherein the plurality of photoelectric probes (160302) are installed at intervals along the movement direction of the armature (2) on the outer walls of the first-level gas pump pipe (103), the first-level electromagnetic pump pipe (501) and the first-level high-pressure pump pipe (7), and the photoelectric sensor body (160301) and the photoelectric probes (160302) are connected via optical fibers; The photoelectric probe (160302) sends a pulse light signal to the armature (2) through the through holes on the walls of the first-level gas pump tube (103), the first-level electromagnetic pump tube (501) and the first-level high-pressure pump tube (7) and receives the reflected light signal. The photoelectric sensor body (160301) converts the light signal into an electrical signal and transmits it to the central controller (1601); The central controller (1601) processes the electrical signal to obtain the moment and speed at which the armature (2) passes through the photoelectric probe (160302), and calculates the expected triggering moment of the to-be-triggered stage according to the timing triggering control method; At the expected triggering moment, the central controller (1601) sends a trigger control signal to the pulse triggering circuit (1602), and the pulse triggering circuit (1602) outputs a power pulse to trigger the turning 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).

13. The ballistic target according to claim 12, wherein: At least m photoelectric probes G are evenly arranged axially backward from the center line of the first-stage driving coil. f1 , G f2 ,…,G fi-1 , G fi ,…,G fm-1 , G fm , the first photoelectric sensor G f1 The axial distance from the center line of the first-stage driving coil is h / 2, and the axial distance between adjacent photoelectric probes is h; v za is the speed of the armature (2) at the center line of the first stage driving coil in the electromagnetic pump tube, t m It is the time interval when the discharge current of the driving coil rises from zero to the maximum value; At least n photoelectric probes G are evenly arranged axially forward from the center line of the first-stage driving coil. z1 , G z2 ,…,G zj , G zj+1 ,…,G zn-1 , G zn , the first photoelectric sensor G z1 Located on the pipe wall between the first and second stage drive coils, the first photoelectric sensor G z1 The distance from the center line of the first stage driving coil is the same as the first photoelectric probe G z1 The distance between the center lines of the second-stage driving coil is equal, and the axial spacing between adjacent photoelectric probes is h.

14. A ballistic target based on a three-stage light gas gun driven by electromagnetic catapult, characterized in that: The invention comprises a first-stage gas propulsion section (1), an electromagnetic ejection device (5), an armature (2), a first-stage piston (3), a first-stage high-pressure pump pipe (7), a first-stage and second-stage connecting mechanism (8), a second-stage pump pipe (10), a second-stage piston (9), a second-stage and third-stage connecting mechanism (11), a projectile (12), a launch tube (13), an expansion tank (14), a test chamber (15) and a measurement and control system (16); wherein, The first-stage gas propulsion section (1) comprises a first-stage gas chamber (101) and a first-stage gas pump pipe (103); The electromagnetic ejection device (5) comprises a primary electromagnetic pump tube (501), a multi-stage drive coil (502) wound on the primary electromagnetic pump 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 first and second level connection mechanism (8) includes a second level air chamber (802) and a second level diaphragm (801); the second and third level connection mechanism (11) includes a third level air chamber (1102) and a third level diaphragm (1101); the first level gas pump pipe (103), the first level electromagnetic pump pipe (501), the first level high pressure pump pipe (7), and the second level air chamber (802) are connected in sequence; the second level air chamber (802) is connected to the second level pump pipe (10) with the second level diaphragm (801) provided therebetween; the second level pump pipe (10) is connected to the third level air chamber (1102); the third level air chamber (1102) is connected to the launch tube (13) with the third level diaphragm (1101) provided therebetween; the launch tube (13) is connected to the expansion tank (14) and the test chamber (15) in sequence; The inlet section of the first-stage gas pump tube (103) is equipped with an armature (2) and a first-stage piston (3), the armature (2) is located behind the first-stage piston (3), the inlet section of the second-stage pump tube (10) is equipped with a second-stage piston (9), the second-stage piston (9) is located in front of the second-stage diaphragm (801), and the inlet section of the launch tube (13) is equipped with a projectile (12), the projectile (12) is located in front of the third-stage diaphragm (1101); The first-stage air chamber (101) releases high-pressure gas, driving the armature (2) and the first-stage piston (3) to move forward and fly out of the first-stage gas pump pipe (103); The electromagnetic ejection device (5) generates pulse current and pulse magnetic field through discharge of a multi-stage driving coil (502); The excitation power supply (505) is triggered step by step to discharge the multi-stage drive coil (502) step by step, and the armature (2) moves under the combined action of the gas thrust and the electromagnetic force generated by the multi-stage drive coil (502) and pushes the first-stage piston (3), and the first-stage piston (3) flies out of the electromagnetic pump pipe and enters the first-stage high-pressure pump pipe (7); The first-stage gas pump tube (103), the first-stage electromagnetic pump tube (501), the first-stage high-pressure pump tube (7) and the second-stage air chamber (802) in front of the first-stage piston (3) are filled with light gas. The light gas in the first-stage gas pump tube (103), the first-stage electromagnetic pump tube (501), the first-stage high-pressure pump tube (7) and the second-stage air chamber (802) breaks through the second-stage diaphragm (801) under the compression of the first-stage piston (3), thereby pushing the second-stage piston (9) to move forward in the second-stage pump tube (10); The secondary pump tube (10) and the tertiary air chamber (1102) in front of the secondary piston (9) are filled with light gas. The light gas in the secondary pump tube (10) and the tertiary air chamber (1102) breaks through the tertiary diaphragm (1101) under the compression of the secondary piston (9), driving the projectile (12) to fly out of the launch tube (13) and enter the test chamber (15) through the expansion box (14); The measurement and control system (16) is used to determine the triggering time of each level of the excitation power supply (505) according to the moving speed and position of the armature (2); The measurement and control system (16) includes a central controller (1601), a pulse trigger circuit (1602) and an armature speed measuring device (1603); The armature speed measuring device (1603) comprises a photoelectric sensor body (160301) and a plurality of photoelectric probes (160302), wherein the plurality of photoelectric probes (160302) are installed at intervals along the movement direction of the armature (2) on the outer walls of the first-level gas pump pipe (103), the first-level electromagnetic pump pipe (501) and the first-level high-pressure pump pipe (7), and the photoelectric sensor body (160301) and the photoelectric probes (160302) are connected via optical fibers; The photoelectric probe (160302) sends a pulse light signal to the armature (2) through the through holes on the walls of the first-level gas pump tube (103), the first-level electromagnetic pump tube (501) and the first-level high-pressure pump tube (7) and receives the reflected light signal. The photoelectric sensor body (160301) converts the light signal into an electrical signal and transmits it to the central controller (1601); The central controller (1601) processes the electrical signal to obtain the moment and speed at which the armature (2) passes through the photoelectric probe (160302), and calculates the expected triggering moment of the to-be-triggered stage according to the timing triggering control method; At the expected triggering moment, the central controller (1601) sends a trigger control signal to the pulse triggering circuit (1602), and the pulse triggering circuit (1602) outputs a power pulse to trigger the switching on of the to-be-triggered stage excitation power supply (505), causing the energy storage pulse capacitor group (50501) of the to-be-triggered stage excitation power supply (505) to discharge through the driving coil (502); At least m photoelectric probes G are evenly arranged axially backward from the center line of the first-stage driving coil. f1 , G f2 ,…,G fi-1 , G fi ,…,G fm-1 , G fm , the first photoelectric sensor G f1 The axial distance from the center line of the first-stage driving coil is h / 2, and the axial distance between adjacent photoelectric probes is h; v za is the speed of the armature (2) at the center line of the first stage driving coil in the electromagnetic pump tube, t m It is the time interval when the discharge current of the driving coil rises from zero to the maximum value; At least n photoelectric probes G are evenly arranged axially forward from the center line of the first-stage driving coil. z1 , G z2 ,…,G zj , G zj+1 ,…,G zn-1 , G zn , the first photoelectric sensor G z1 Located on the pipe wall between the first and second stage drive coils, the first photoelectric sensor G z1 The distance from the center line of the first stage driving coil is the same as the first photoelectric probe G z1 The distance between the center line of the second-stage driving coil is equal to that of the adjacent photoelectric probes, and the axial distance between the adjacent photoelectric probes is h; The timing trigger control method includes: Step 1: The first-stage air chamber (101) releases gas to drive the armature (2) to push the first-stage piston (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; the following steps 2-1 and 2-2 are executed cyclically until the first-stage excitation power supply (505) 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 (1603) performs measurement, and the central controller (1601) performs signal processing to obtain the armature (2) speed v at this moment and this position fi ; Step 2-2: if Then the first stage excitation power supply (505) is triggered after a delay time Δt1, and the delay time Δt1 satisfies: Let s = s + 1, let i = i - 1, jump out of this loop and execute step 3; if Then no excitation power supply (505) is to be triggered, and i=i-1; Step 3: Circulate 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; 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 (1603) performs measurement, and the central controller (1601) performs signal processing to obtain the armature (2) speed v at this moment and this position fi ; Step 3-2: if Then the s-th level excitation power supply (505) is immediately triggered, and s=s+1 and i=i-1; if Then at the delay time Δt s Then trigger the s-th level excitation power supply (505), the delay time Δt s satisfy: Let s = s + 1, let i = i - 1; if Then no excitation power supply (505) 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 G in front of the center line of the first stage driving coil z1 When the s-th level excitation power supply (505) is triggered to turn on, this moment is t s , the distance between the armature (2) and the center line of the first stage driving coil is x s =h / 2; the armature speed measuring device (1603) performs measurement, and the central controller (1601) performs signal processing to obtain t s The speed of the armature (2) at this moment is v s ; Step 5: cyclically execute the following steps 5-1, 5-2 and 5-3 until the moment t at which the n-th stage excitation power supply (505) is turned on is obtained. n : Step 5-1: At time t s+1 Triggering the conduction of the s+1th level excitation power supply (505), the time t s+1 satisfy: v s is time t s Armature (2) speed, a is the average acceleration of armature (2) motion, h is the center distance between two adjacent drive coils, t m It 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 (1601) calculates the time t s+1 The estimated speed of the armature (2) is Step 5-3: Let s=s+1.

15. The ballistic target according to claim 14, wherein The photoelectric probe (160302) is used to detect the rear end of the armature (2).

16. The ballistic target according to claim 14, wherein:

17. The ballistic target according to claim 14, wherein: t m according to OK, L d It is the sum of all self-inductances of the discharge circuit before the discharge current of the driving coil is freewheeled by the diode, and C is the capacitance value of the energy storage capacitor group.

18. The ballistic target according to claim 14, wherein Time t s+1 The distance between the armature (2) and the center line of the first stage driving coil is x s+1 Satisfy: x s+1 =x s +h-at m (t s+1 -t s )<x s +h,x s is time t s The distance between the armature (2) and the center line of the first-stage driving coil.

19. The ballistic target according to claim 14, wherein The armature (2) passes through the jth photoelectric probe G in front of the center line of the first stage driving coil zj , j+1th photoelectric sensor G zj+1 The time and speed are t zj 、v zj and t zj+1 、v zj+1 , the armature (2) passes the j+1th photoelectric probe G in front of the center line of the first stage driving coil zj+1 The estimated time and speed are 20. A timing trigger control method, the method being applied to the ballistic target according to claim 13, the method comprising: Step 1: The first-stage air chamber releases gas to drive the armature to push the first-stage piston 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; repeat 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 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 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 at this moment and this position fi ; Step 2-2: if Then the first stage excitation power supply is triggered after the delay time Δt1, and the delay time Δt1 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: Repeat the steps 3-1 and 3-2 until the armature passes the first photoelectric probe behind 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-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 at this moment and this position fi ; 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 at the delay time Δt s After triggering the s-th level excitation power supply, the delay time Δt s satisfy: 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 G in front of the center line of the first stage drive coil z1 When the s-th level excitation power supply is triggered and turned on, this moment is t s , the distance between the armature and the center line of the first stage drive coil is x s =h / 2; the armature speed measuring device performs measurement and the central controller performs signal processing to obtain t s The armature speed v at this position at this moment s ; Step 5: Loop through the following steps 5-1, 5-2, and 5-3 until the moment t at which the n-th stage excitation power supply is turned on is obtained. n : Step 5-1: At time t s+1 Triggering the conduction of the s+1th level excitation power supply, the time t s+1 satisfy: v s is time t s Armature speed, a is the average acceleration of armature motion, h is the center distance between two adjacent drive coils, t m It 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: Calculate the time t through the central controller s+1 The expected armature speed is Step 5-3: Let s=s+1.

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