阅读说明：本技术 一种炮弹加速距离可控的磁阻式电磁炮及控制方法 (Magnetic resistance type electromagnetic gun with controllable shell acceleration distance and control method ) 是由 钟德刚 郑露华 吴春 于 2020-10-22 设计创作，主要内容包括：一种炮弹加速距离可控的磁阻式电磁炮,包括炮管、炮弹、主电路及控制电路,控制电路包含单片机及MOSFET驱动电路,通过控制器对主电路中的MOSFET的控制实现电磁炮加速线圈充放电时间的精确控制进而主动改变线圈内部的强磁场的维持时间,加速线圈磁场的变化与炮弹的加速距离有直接关系,通过多次测试获得线圈通电时间与炮弹射程的关系,最后利用这种关系实现炮弹加速距离的控制最终改变炮弹的射程。以及提供一种炮弹加速距离可控的磁阻式电磁炮的控制方法。本发明可有效解决常规磁阻式线圈炮电容容量选择困难、加速效率低等问题,并提高了炮弹的最大出口速度；同时在不增加其它控制装置的情况下,即可实现炮弹射程可控。(A magnetic resistance type electromagnetic gun with controllable accelerating distance of a cannonball comprises a gun barrel, the cannonball, a main circuit and a control circuit, wherein the control circuit comprises a single chip microcomputer and a MOSFET drive circuit, accurate control of charging and discharging time of an accelerating coil of the electromagnetic gun is achieved through control of a controller on MOSFET in the main circuit, maintaining time of a strong magnetic field inside the coil is actively changed, direct relation exists between change of a magnetic field of the accelerating coil and the accelerating distance of the cannonball, the relation between coil electrifying time and cannonball firing range is obtained through multiple tests, and finally the firing range of the cannonball is finally changed through control of the accelerating distance of the cannonball. And provides a control method of the magnetic resistance type electromagnetic cannon with controllable cannonball acceleration distance. The invention can effectively solve the problems of difficult selection of capacitance capacity, low acceleration efficiency and the like of the conventional reluctance type coil cannon, and improves the maximum outlet speed of the cannon; meanwhile, the range of the cannonball can be controlled under the condition of not increasing other control devices.)

1. A reluctance type electromagnetic cannon with controllable cannonball acceleration distance is characterized in that the reluctance type electromagnetic cannon comprises a cannon barrel, a cannonball, a main circuit and a controller,

the gun barrel consists of an accelerating coil and a plastic pipeline, the length of the accelerating coil is longer than that of the cannonball and is connected with a main circuit, the main circuit controls a current circulation path to realize the charging of a capacitor bank, the charging of the accelerating coil and the discharging of the residual energy of the accelerating coil, the size of the capacitor bank meets the condition that the voltage is reduced by less than 10 percent when the accelerating coil is charged, the controller consists of a single chip microcomputer and a driving chip of a power tube, the effective control on the main circuit is completed to realize the whole launching process of the reluctance type coil cannonball, and the outer diameter of the cannonball is close to the inner diameter of the gun barrel;

when the cannonball passes through the accelerating coil, the inductance of the coil presents a curve which rises firstly and then basically keeps unchanged and then falls, and because the magnitude of the magnetic resistance is in negative correlation with the inductance, if the voltage at two ends of the coil basically keeps unchanged in the running process of the cannonball, the cannonball moves by first accelerating, then equalizing speed and then decelerating; by controlling the discharge time t of the accelerating coil, the magnetic field change in the coil is actively changed, so that the accelerating interval of the cannonball is changed.

2. A magnetoresistive electromagnetic cannon with controllable cannonball acceleration distance as claimed in claim 1, characterized in that the main circuit comprises a controllable DC voltage regulator, a capacitor bank (C1), MOSFETs (VT1, VT2), a Schottky diode (D1), a power resistor (R1) and a coil, wherein the DC voltage source is connected in series with the capacitor bank (C1) and the MOSFET (VT2) to form a capacitor bank charging circuit, the capacitor bank (C1) is connected in series with the coil and the MOSFET (VT1) to form a capacitor bank discharging circuit, and the two ends of the coil are connected in parallel with an acceleration coil energy discharging circuit formed by the power resistor (R1) and the Schottky diode (D1).

3. A method for controlling a magnetoresistive electromagnetic cannon having a controllable cannonball acceleration distance as claimed in claim 1, wherein the method comprises the steps of:

(1) the gun barrel is fixed on the stable support, the gun barrel is inclined upwards for a set angle, the cannonball is loaded in place, and circuits of all parts are reliably connected;

(2) the controller controls the voltage-stabilized power supply to charge the capacitor bank;

(3) setting the discharge time t of the capacitor bank to the accelerating coil;

(4) stopping charging the capacitor bank, discharging the capacitor bank to the accelerating coil, stopping discharging the capacitor bank to the accelerating coil after t seconds, quickly releasing energy by the accelerating coil through a discharge circuit, and ejecting the cannonball;

(5) measuring and recording the shooting distance x of the cannonball;

(6) changing the discharge time t of the capacitor, and repeating the steps (2) to (5) to obtain different discharge times t₁，t₂，…，t_nShooting distance x of lower shell₁，x₂，…，x_n。

(7) Fitting the relation t ═ f (x) between the shooting distance of the cannonball and the discharge time by using a least square method;

(8) by using the relation t of the cannonball range and the discharge time f (x), the accelerating distance of the cannonball can be changed by only changing the discharge time t, and the cannonball range is controlled.

Technical Field

The invention belongs to the technical field of electromagnetic gun launching, and relates to a magnetic resistance type electromagnetic gun based on shell acceleration distance control and a control method.

Background content

The electromagnetic emission technology has been proposed in the first 19 th century, and at present, as the emission performance of the chemical energy emission device tends to be improved to the limit, the obstacles of the development of the electromagnetic emission technologies such as conductive materials, power supply and insulation technologies are removed one by one, and the development of the electromagnetic emission technology is gradually paid attention. Compared with the traditional mechanical energy and chemical energy emission technology, the electromagnetic emission technology has the following advantages: the device has the advantages of excellent acceleration capability, large emission quality, easy energy acquisition, good controllability and the like.

At the present stage, the reluctance type coil cannon is quite common, and the reluctance type coil cannon generally comprises a cannon barrel wound with an accelerating coil, an energy storage capacitor, a control circuit and a cannonball made of ferromagnetic materials, and the cannonball is pulled to move forwards in an accelerating mode by a strong magnetic field when the coil is electrified. When the cannonball passes through the center of the accelerating coil, the magnetic force which originally drives the cannonball to move forwards is changed into backward resistance, so that the capacity of an energy storage capacitor of a common reluctance type coil cannon cannot be too large, the magnetic field intensity is attenuated to a small value when the cannonball passes through the position with the maximum magnetic flux, and the reverse resistance to the cannonball is reduced. Therefore, the existing reluctance type coil cannon has the following defects:

(1) the capacitance capacity is very difficult to select, and whether the time of magnetic field intensity attenuation is close to or even the same as the time of the cannonball crossing the maximum magnetic flux position is difficult to ensure;

(2) in the accelerating process of the cannonball, the acceleration of the cannonball is quickly attenuated along with the change of a magnetic field, the maximum outlet speed of the cannonball is severely limited, and the efficiency of the electromagnetic cannonball is reduced;

(3) the range of the conventional magnetic resistance type coil cannon needs to be adjusted by means of a cannon barrel elevation angle, capacitor bank charging voltage and the like, so that an additional device is needed, and the size and the complexity of the electromagnetic cannon are increased.

Disclosure of Invention

In order to solve the defects that the existing reluctance type coil cannon is difficult in capacitance selection, low in cannonball acceleration efficiency, and requires an additional device to control the cannonball range, the invention provides a reluctance type coil cannon with controllable acceleration distance and a control method.

The technical scheme adopted by the invention for realizing the aim is as follows:

a magnetic resistance type electromagnetic cannon with controllable cannonball acceleration distance comprises a cannon barrel, a cannonball, a main circuit and a controller,

the gun barrel consists of an accelerating coil and a plastic pipeline, the length of the accelerating coil is longer than that of the cannonball and is connected with a main circuit, the main circuit controls a current circulation path to realize the charging of a capacitor bank, the charging of the accelerating coil and the discharging of the residual energy of the accelerating coil, the size of the capacitor bank meets the condition that the voltage is reduced by less than 10% when the accelerating coil is charged, the controller consists of a single chip microcomputer and a driving chip of a power tube, the effective control on the main circuit is completed to realize the whole launching process of the reluctance type coil cannonball, the outer diameter of the cannonball is close to the inner diameter of the gun barrel to reduce the reluctance and reduce the shake of the cannonball when the cannonball slides, and meanwhile, the cannonball can;

when the cannonball passes through the accelerating coil, the inductance of the coil presents a curve which rises firstly and then basically keeps unchanged and then falls, and because the magnitude of the magnetic resistance is in negative correlation with the inductance, if the voltage at two ends of the coil basically keeps unchanged in the running process of the cannonball, the cannonball moves by first accelerating, then equalizing speed and then decelerating; by controlling the discharge time t of the accelerating coil, the magnetic field change in the coil is actively changed, so that the accelerating interval of the cannonball is changed.

Further, the main circuit comprises a controllable direct current voltage stabilizing source, a capacitor bank (C1), MOSFETs (VT1, VT2), Schottky diodes (D1), a power resistor (R1) and coils, wherein the direct current voltage source is connected with the capacitor bank (C1) and the MOSFETs (VT2) in series to form a capacitor bank charging loop, the capacitor bank (C1) is connected with the coils and the MOSFETs (VT1) in series to form a capacitor bank discharging loop, and two ends of each coil are connected with an acceleration coil energy discharging loop formed by the power resistor (R1) and the Schottky diodes (D1) in parallel.

The cannonball is made of iron or other materials with good magnetic permeability;

a method of controlling a magnetoresistive electromagnetic cannon having a controllable cannonball acceleration distance, the method comprising the steps of:

(1) the gun barrel is fixed on the stable support, the gun barrel is inclined upwards for a set angle, the cannonball is loaded in place, and circuits of all parts are reliably connected;

(2) the controller controls the voltage-stabilized power supply to charge the capacitor bank;

(3) setting the discharge time t of the capacitor bank to the accelerating coil;

(4) stopping charging the capacitor bank, discharging the capacitor bank to the accelerating coil, stopping discharging the capacitor bank to the accelerating coil after t seconds, quickly releasing energy by the accelerating coil through a discharge circuit, and ejecting the cannonball;

(5) measuring and recording the shooting distance x of the cannonball;

(6) changing the discharge time t of the capacitor, and repeating the steps (2) to (5) to obtain different discharge times t₁，t₂，…，t_nShooting distance x of lower shell₁，x₂，…，x_n。

(7) Fitting the relation t ═ f (x) between the shooting distance of the cannonball and the discharge time by using a least square method;

(8) by using the relation t of the cannonball range and the discharge time f (x), the accelerating distance of the cannonball can be changed by only changing the discharge time t, and the cannonball range is controlled.

The invention has the following beneficial effects:

1) by accurately controlling the charging and discharging time of the coil, the accelerating distance of the cannonball can be changed, the shooting range of the cannonball can be controlled under the condition that the voltage of a capacitor bank, the elevation angle of a cannonball tube and the like are not changed, and the complexity of the device and the control is simplified.

2) By actively controlling the charging and discharging of the accelerating coil, the size of the capacitor bank can be simply selected as long as the capacitor bank is large enough.

3) The capacitor discharge time is related to the cannonball range, and energy does not need to be discharged every time of shooting. The recharging time of the capacitor is shortened, the service life is prolonged, and the efficiency of the device is improved.

4) In the accelerating process of the cannonball, the magnetic field intensity of the coil is not attenuated basically, and the cannonball can obtain higher outlet speed, so that the volume and the mass of the electromagnetic cannonball can be smaller under the condition of meeting the same outlet speed.

Drawings

FIG. 1 is a system block diagram of the present invention.

FIG. 2 shows the theoretical calculation result of the inductance of the acceleration coil and the position of the cannonball.

Fig. 3 is the actual measurement of acceleration coil inductance versus projectile position.

Fig. 4 shows a current flow path during charging of the capacitor bank.

Fig. 5 is a current flow path for charging the accelerating coil with energy from the capacitor bank.

Fig. 6 is a current flow path when the accelerating coil bleeds energy.

Detailed description of the invention

The invention is further described below with reference to the accompanying drawings.

Referring to fig. 1-6, a magnetic resistance type electromagnetic cannon with controllable cannonball acceleration distance comprises a cannon barrel 3, a cannonball 1, a main circuit and a control circuit, wherein the cannon barrel consists of an acceleration coil 2 and a plastic pipeline, and the cannonball 1 is made of iron or other materials with good magnetic conductivity; the length of the accelerating coil 2 is longer than that of the shell and is connected with a main circuit, the main circuit controls a current circulation path to realize the charging of a capacitor bank, the charging of the accelerating coil and the discharging of the residual energy of the accelerating coil, the size of the capacitor bank meets the condition that the voltage drop is less than 10% when the accelerating coil is charged, the controller consists of a single chip microcomputer and a driving chip of a power tube, the effective control of the main circuit is completed to realize the whole launching process of the reluctance type coil shell, the outer diameter of the shell is close to the inner diameter of a shell tube to reduce the reluctance and reduce the shake of the shell when the shell slides, and meanwhile, the shell can slide smoothly in the shell tube;

when the cannonball passes through the accelerating coil, the inductance of the coil presents a curve which rises firstly and then basically keeps unchanged and then falls, and because the magnitude of the magnetic resistance is in negative correlation with the inductance, if the voltage at two ends of the coil basically keeps unchanged in the running process of the cannonball, the cannonball moves by first accelerating, then equalizing speed and then decelerating; by controlling the discharge time t of the accelerating coil, the magnetic field change in the coil is actively changed, so that the accelerating interval of the cannonball is changed.

The main circuit comprises a controllable direct current voltage stabilizing source, a capacitor bank (C1), a MOSFET (VT1, VT2), a Schottky diode (D1), a power resistor (R1) and a coil, wherein the direct current voltage source is connected with the capacitor bank (C1) and the MOSFET (VT2) in series to form a capacitor bank charging loop, the capacitor bank (C1) is connected with the coil and the MOSFET (VT1) in series to form a capacitor bank discharging loop, and two ends of the coil are connected with an acceleration coil energy discharging loop formed by the power resistor (R1) and the Schottky diode (D1) in parallel. The controller consists of a singlechip and a drive circuit of an MOSFET (metal-oxide-semiconductor field effect transistor), the outer diameter of the cannonball is close to the inner diameter of the cannonball tube as much as possible so as to reduce the magnetic resistance and the shake of the cannonball during sliding, and meanwhile, the cannonball can smoothly slide in the cannonball tube.

When current flows through the coil, magnetic energy is stored in the magnetic field around the coil, and the magnetomotive force generated by the electrified coil is as follows:

F_m＝Ni＝ΦR_m#(1.1)

the magnetic energy stored by an ideal air-core coil can be expressed as:

according to the principle of virtual work, the pulling force of the electrified coil on the cannonball can be expressed as follows:

in the formula: n is the number of coil turns, i is the current in the coil, d Φ/dx is the rate of change of flux with displacement. The magnetic flux phi is related to the structural parameters of the coil, the material and shape of the projectile, the coil current, and varies with the position of the projectile relative to the coil.

The above formula approximately gives the stress condition in the cannonball movement process, and the magnetic flux in the practical situation is difficult to measure, but the current in the coil is supposed to be kept basically constant when the cannonball is launched, and the inductance variation trend of the coil along with the cannonball movement is basically consistent with the variation of the magnetic flux. Therefore, the stress condition of the cannonball in the coil can be analyzed by analyzing the inductance variation trend of the coil along with the movement of the cannonball.

Referring to fig. 2, this is the theoretical calculation of the inductance of the accelerating coil for different positions of the projectile in the coil. Because the magnetic resistance is in negative correlation with the inductance, the magnetic resistance of the coil is firstly reduced and then increased in the process of passing the cannonball through the coil. The inductance value of the coil is kept unchanged because the position of the cannonball is changed after the cannonball completely enters the coil, and the size of the magnetic resistance is basically not influenced, so that the length of the coil is slightly larger than the length of the cannonball.

Referring to fig. 3, this is an actual measurement of the inductance of the acceleration coil at different positions of the projectile in the coil. Because the accelerating coil is difficult to wind uniformly and the actual shape of the cannonball is different from the theoretical calculation, the actual measurement result of the inductance value can only be approximate to the theoretical calculation. The inductance variation curve actually measured is analyzed to obtain: the inductance rising stage is an acceleration interval of the cannonball; during the platform period when the inductance is basically unchanged, the shell approaches a uniform motion state; when the cannonball runs to the coil inductance value descending interval and the coil energy is not completely released, the cannonball is subjected to reverse driving force to perform deceleration movement.

The above analysis leads to the following conclusions about the manufacture and control of electromagnetic guns:

(1) the length of the electromagnetic gun accelerating coil is slightly longer than the length of the shell;

(2) when the cannonball runs to the beginning position of the inductance platform period, the energy supply of the coil is stopped, so that the outlet speed of the cannonball can reach the maximum;

(3) the accelerating distance of the cannonball can be effectively controlled by cutting off the energy supply of the coil at different times in the accelerating process of the cannonball, so that the outlet speed of the cannonball is changed.

Referring to fig. 4, this is a current flow path during charging of the capacitor bank. When the capacitor bank C1 is charged, the control circuit controls the VT2 to be turned on, and the dc voltage source charges the capacitor bank C1.

Referring to fig. 5, this is the current flow path for the capacitor bank to charge the accelerating coil. The control circuit controls VT2 to be switched off and VT1 to be switched on, the capacitor bank C1 releases electric energy to the accelerating coil, and the cannonball starts to move under the action of the magnetic field. The turn-on time of VT1 is denoted as t. The circuit can be equivalent to an RLC series circuit, and the voltage of the capacitor bank is U_c(t) the loop current is represented by I (t)The total loop resistance is denoted by R.

Current in the loop:

voltage across capacitor bank:

referring to fig. 6, this is the current flow path when the accelerating coil is discharging energy. The control circuit should turn off VT1 t seconds after capacitor bank C1 releases electric energy to the accelerating coil, so that the energy in the coil is quickly discharged through schottky diode D1 and power resistor R1, and the magnetic field strength is quickly attenuated. The circuit is equivalent to an RL series circuit, and the initial current of the circuit is I₀The decay of the current in the circuit over time can be expressed as:

a method of controlling a magnetoresistive electromagnetic cannon having a controllable cannonball acceleration distance, the method comprising the steps of:

(1) the gun barrel is fixed on the stabilizing support, and the gun barrel is inclined upwards by a certain angle, in the embodiment, 45 degrees is selected. The cannonball is loaded in place, and the circuits of all parts are reliably connected;

(2) the controller controls the voltage-stabilized power supply to charge the capacitor bank;

(3) setting the discharge time t of the capacitor bank to the accelerating coil;

(4) stopping charging the capacitor bank, discharging the capacitor bank to the accelerating coil, stopping charging the accelerating coil by the capacitor bank after t seconds, quickly releasing energy by the accelerating coil through a discharge circuit, and ejecting the cannonball;

(5) measuring and recording the shooting distance x of the cannonball;

(6) changing the discharge time t of the capacitor, and repeating the steps (2) to (5) to obtain a group of different discharge times t₁，t₂，…，t_nShooting distance x of lower shell₁，x₂,…，x_n；

(7) The present embodiment uses a least square method to fit the relationship x ═ f (t) between the shooting distance of the cannonball and the discharge time;

(8) by using the relation x of the cannonball range and the discharge time f (t), the accelerating distance of the cannonball can be changed by only changing the discharge time t, and then the cannonball range is controlled.

The embodiments described in this specification are merely illustrative of implementations of the inventive concepts, which are intended for purposes of illustration only. The scope of the present invention should not be construed as being limited to the particular forms set forth in the examples, but rather as being defined by the claims and the equivalents thereof which can occur to those skilled in the art upon consideration of the present inventive concept.