Missile-gun coupling effect angle monitoring method

Abstract

The application discloses a kind of gun projectile coupling effect angle monitoring method.Step one: according to the requirement of shooting, the artillery is arranged to the gun position, adopts quadrant instrument to adjust the angle of fire to the specified angle, rotates direction machine and makes the direction of fire to the specified angle.Step two: the side electronic theodolite is arranged on the ground on the right side of muzzle;The rear electronic theodolite is arranged on the ground directly behind the artillery.The theodolite support is reliably fixed on the ground.The side theodolite monitors the angle of fire, and the rear theodolite monitors the direction of fire.Step three: before the first projectile shooting, after adjusting the angle of fire and the direction of fire by quadrant instrument and direction machine, the angle of fire and the direction of fire of artillery before shooting are determined by theodolite.Step four: according to step three, the angle of fire and the direction of fire monitoring value of the second projectile to the n projectile before shooting are determined, and the difference between monitoring value and aiming value is obtained.Step five: after a group of projectiles complete shooting, the relationship between angle error and projectile landing point coordinates is analyzed, whether the shooting density is related to the angle of fire and the direction of fire monitoring value and the influence law are judged.

Description

Technical Field

[0001] This invention relates to a method for monitoring the firing angle of a projectile-gun coupling effect. Specifically, this invention relates to a method for monitoring changes in firing angle and direction during artillery firing based on an electronic theodolite. Background Technology

[0002] During artillery firing, the projectile undergoes not only high-speed translational motion within the barrel but also high-speed rotation around the barrel's axis and oscillation relative to that axis, creating the so-called projectile-gun coupling effect. This coupling effect causes random thermal deformation of the cradle and barrel, leading to random changes in the firing angle. Ultimately, this results in increased errors in firing angle measurement, deteriorating the artillery's firing accuracy.

[0003] The operating characteristics of artillery weapons are high temperature, high pressure, and high speed. After the gunpowder is ignited, it burns rapidly, generating high-temperature, high-pressure propellant gases that propel the projectile through the barrel with violent acceleration until it leaves the muzzle at high speed. Upon initiation, the recoil portion of the projectile recoils along the barrel axis. After leaving the muzzle, the high-temperature, high-pressure propellant gases are expelled, creating a complex aftereffect period that causes the recoil portion to continue recoiling until it stops at a predetermined length. Due to the strong excitation of the propellant gases on the artillery, not only does the recoil portion recoil, but all parts of the entire gun are also subjected to intense excitation, resulting in highly complex motion and stress. Firing not only causes strong translational movement of the artillery but also strong jumping and rotation, accompanied by strong impacts between components and high-speed time-varying vibrations throughout the gun. The artillery will produce very complex nonlinear vibrations. The entire operating process of the artillery lasts approximately tens to hundreds of milliseconds, exhibiting strong transient and random characteristics.

[0004] When a cannon is fired, the axial resultant force of the propellant gases in the barrel (called the barrel force or recoil force) causes the gun barrel and its fixed parts to move in the opposite direction to the projectile's travel; this action is called recoil. To reduce the force acting on the gun carriage, a special "buffer device" is added between the recoil section and the cradle; this "buffer device" is called a recoil deflector. This buffering effect does not change the total impulse of the propellant gases acting on the cannon; it simply transforms the large, instantaneously changing barrel force into a smaller, more gradually changing, and longer-lasting recoil resistance.

[0005] The "buffer device" is a hydraulic system that uses a recoil mechanism to buffer the recoil energy generated during firing. The fluid in the hydraulic system is a recoil-damping fluid. When the artillery fires, the barrel recoils and returns to its starting position. Simultaneously, the recoil-damping rod in the recoil mechanism moves along the recoil cylinder. The piston at the front of the recoil rod compresses the recoil-damping fluid, causing its temperature to rise. One of the main components of the recoil mechanism is the recoil brake. A small portion of the recoil energy is dissipated through friction and heat loss; most of it is absorbed by the recoil-damping fluid, causing it to heat up. This increased fluid temperature leads to a rise in the temperature of the recoil brake mechanism. Because the recoil brake is often located on the upper part of the cradle, in an asymmetrical arrangement relative to the cradle's vertical axis, the thermal expansion and deformation of the upper and lower parts of the cradle are uneven. The upper part of the cradle has a higher temperature and greater thermal expansion and deformation, while the lower part has a lower temperature and almost no thermal expansion and deformation. This causes the cradle axis to bend and deform. During the firing density assessment of large-caliber artillery, a set of shots consists of n rounds (typically n = 7-9 rounds). As the firing sequence increases, the temperature of the recoil fluid increases with each round (each round causes a temperature rise of 1-2°C in the recoil fluid). With the recoil mechanism positioned above the firing mechanism, as the firing sequence increases, the cradle axis bends downwards with each round, causing the elevation and depression angles to decrease progressively, resulting in a progressively larger projectile dispersion. Under the condition of progressively downward bending deformation of the cradle axis due to thermal factors, an abnormal phenomenon often occurs during maximum range ground density tests: the projectile impact points become increasingly closer with each shot. This dispersion pattern degrades the artillery's maximum range ground density performance, sometimes failing to meet tactical and technical requirements.

[0006] The cradle is a crucial component of an artillery piece. Its functions include supporting the recoil mechanism and providing guideways for the recoil and return motion of the gun barrel; providing a pivot for the gun barrel's elevation and depression; providing fulcrums or connection points for connecting with certain components and parts; and transferring loads to other parts of the frame during firing. The cradle is the main body of the elevation and depression mechanism, forming the gun barrel's elevation or depression section together with the recoil mechanism and other related mechanisms. It works in conjunction with the elevation mechanism and sights to give the gun barrel an elevation and depression angle. Sights are also mounted on the cradle. Large-caliber artillery often uses a cylindrical cradle, whose main components include the cradle body, front and rear brass liners, a front support, and a rear support. The front and rear supports are used to connect and fix the recoil mechanism.

[0007] During the firing process, the high-temperature, high-pressure, high-speed gas flow inside the gun barrel can reach temperatures of several thousand degrees Celsius. As the number of projectiles fired increases, the barrel temperature rises sharply. Due to various factors, the temperature distribution within the barrel structure is uneven, causing the barrel axis direction to change with the number of projectiles fired, ultimately leading to random changes in the gun's firing angle. This random change in firing angle is uncontrollable by the gun operator beforehand. The angle between the gun barrel axis and the horizontal plane is defined as the firing angle, and the angle between the projection of the barrel axis onto the horizontal plane and the left and right symmetrical planes of the gun is defined as the firing direction. Since the barrel axis direction cannot be measured quickly, it is converted into a measurement of the firing angle reference direction on the cradle. During gun design, a reference plane is selected on the cradle. At a firing angle of 0 degrees, this plane is parallel to the barrel axis, and its normal lies in the vertical plane. The firing angle direction is represented by the direction of the reference plane on the cradle. In actual operation, the quadrant is placed on this reference plane and adjusted until its horizontal bubble is centered; the quadrant's angle reading represents the firing angle reading. Before the artillery pieces leave the factory, the relationship between the reference plane and the firing angle is calibrated. During actual firing, the firing angle can be determined simply by placing a quadrant on this reference plane. However, due to the thermal deformation of the cradle and barrel caused by the firing process, unpredictable measurement errors occur in the firing angle measurement, ultimately leading to a decrease in the artillery's firing density and accuracy. The thermal deformation of the cradle caused by the firing process causes the orientation of the reference plane on the cradle to change randomly, introducing measurement errors; the thermal deformation of the barrel caused by the firing process prevents the orientation of the reference plane on the cradle from reflecting this change, also introducing measurement errors.

[0008] An electronic theodolite is a common optical measuring instrument, frequently used for angle measurement, with angle readings typically displayed digitally. The electronic theodolite's barrel contains a crosshair scale and has one horizontal and one vertical axis. With the aid of a pan-tilt head, the electronic theodolite's barrel can rotate with three degrees of freedom. When aligned with the gun muzzle, the electronic theodolite's barrel can detect the gun's firing angle. A quadrant is also an angle measuring instrument, using scale lines and a horizontal bubble to indicate the angle; in the field of artillery, it is commonly used to measure gun firing angles. The artillery involved in this invention primarily refers to large-caliber artillery.

[0009] As modern warfare places higher demands on artillery performance, artillery firing accuracy should also be improved. The impact of thermal deformation of the cradle and barrel on firing accuracy is becoming increasingly apparent. How to accurately test the firing angle and direction of artillery during firing has become a major concern for artillery operators. Summary of the Invention

[0010] To address the problem of accurately testing the firing angle and direction during artillery firing concentration tests, a method for monitoring the firing angle of the missile-gun coupling effect has been invented. This method involves an electronic theodolite, a quadrant, and a laser rangefinder. Two electronic theodolites are used, each with orthogonal crosshairs on its observation tube: one horizontal and one vertical. The electronic theodolite also includes a pan-tilt unit and a support. The pan-tilt unit is mounted on the support, and the observation tube is mounted on the pan-tilt unit. A display panel is located on the base of the observation tube. The steps involved in the method for monitoring the firing angle of the missile-gun coupling effect are as follows:

[0011] Step 1: According to the firing requirements, position the artillery in the gun position, use the quadrant to adjust the firing angle to the specified angle, and rotate the azimuth mechanism to make the firing direction the specified angle.

[0012] Step Two: Deploy the first electronic theodolite, designated as the lateral theodolite, 20 meters to the right of the gun muzzle; deploy the second electronic theodolite, designated as the rear theodolite, directly behind the gun. The supports for both the lateral and rear theodolites are reliably fixed to the ground. The lateral theodolite monitors the firing angle, and the rear theodolite monitors the firing direction.

[0013] Step 3: Before firing the first round, after adjusting the firing angle and direction using the quadrant and azimuth mechanism, determine the artillery's firing angle and direction using an electronic theodolite. Define the values ​​obtained from adjusting the firing angle and direction using the quadrant and azimuth mechanism as the aiming values. For a series of n rounds, the aiming values ​​remain constant. Define the values ​​obtained from determining the artillery's firing angle and direction using the electronic theodolite as the monitoring values. Due to thermal deformation of the artillery structure and other random factors, the monitoring values ​​will be randomly distributed and not constant; therefore, there will be differences between the monitoring values ​​and the aiming values.

[0014] Step 4: Following Step 3, determine the artillery firing angle and trajectory monitoring values ​​before firing the second to the nth rounds, and obtain the difference between the monitoring values ​​and the aiming values. Define the difference between the monitoring values ​​and the aiming values ​​as the angle error.

[0015] Step 5: After a group of projectiles has completed firing, analyze the relationship between the angle error and the coordinates of the projectile's landing point to determine whether the firing density is related to the monitoring values ​​of the firing angle and direction, and what the influencing patterns are.

[0016] The projectile-gun coupling effect firing angle monitoring method has significant advantages: 1) It directly tests the muzzle firing angle and trajectory using an electronic theodolite, accurately reflecting the firing angle and trajectory at the moment the projectile leaves the muzzle; 2) It eliminates the inability of traditional aiming methods to reflect changes in firing angle and trajectory caused by thermal deformation of the artillery structure and random factors, thus improving aiming accuracy; 3) It provides accurate firing angle and trajectory test data for artillery firing density analysis; 4) It can significantly improve the level of artillery testing technology in my country and plays an important supporting role in improving the level of artillery firing tables. Attached Figure Description

[0017] Appendix Figure 1This is a schematic diagram of a method for monitoring the firing angle of a missile-gun coupling effect. In the diagram, 1 represents the cradle, 2 represents the barrel, 3 represents the muzzle, 4 represents the electronic theodolite test line, and 5 represents the electronic theodolite. (Attached) Figure 1 The electronic theodolite positioned directly behind the artillery is not shown in the drawing.

[0018] Appendix Figure 2 This is a schematic diagram for firing angle testing. Points A and B are two adjacent points on the right outer surface of the muzzle along the barrel axis, and α represents the firing angle. The muzzle firing angle is represented by the change in elevation angle along the line connecting points A and B, with upward being positive and downward being negative. (Attached) Figure 2 Points M and N, two adjacent points directly above the outer surface of the muzzle along the barrel axis, are not marked; point M is in front, and point N is behind. Points A and M are observation points, which are equidistant from the muzzle and lie on the same cross-sectional circumference of the muzzle.

[0019] Appendix Figure 3 This is a schematic diagram of separate muzzle elevation and azimuth angle tests. Before the first round is fired, point A at the muzzle is selected as the measuring point. Before the second round is fired, due to thermal deformation of the artillery structure and random factors, point A at the muzzle moves to point C. This is the result of the combined effects of the muzzle firing angle and trajectory. The muzzle trajectory causes point A to move to point D, and the muzzle firing angle causes point A to move to point E. According to the principle of displacement synthesis, point A eventually moves to point C. The displacement of point A caused by the muzzle firing direction is x2, the displacement of point A caused by the muzzle firing angle is y2, and the angle caused by point A observed by the electronic theodolite on the muzzle side is α. 20 The distance from point O, the center of the electronic theodolite tube, to point A is l.

[0020] The elevation angle of the gun muzzle is the firing angle, and the azimuth angle of the gun muzzle is the firing direction.

[0021] Appendix Figure 4 This is a schematic diagram of the muzzle azimuth angle test. Before the first round is fired, point M at the muzzle is selected as the measuring point. Before the second round is fired, due to thermal deformation of the artillery structure and random factors, point M at the muzzle moves to point S. The displacement between M and S is x2. Point P is the center of the rear theodolite tube, and the distance between P and M is h. The muzzle azimuth angle caused by the displacement x2 is β2, which represents the firing direction error. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments. For ground-based concentrated firing tests at maximum range of large-caliber artillery, the method for monitoring the firing angle of the missile-gun coupling effect involves an electronic theodolite, a quadrant, and a laser rangefinder. Two electronic theodolites are used; each has orthogonal crosshairs, one horizontal and one vertical, in its telescope tube for observing the position of the measuring point. The electronic theodolite also includes a pan-tilt unit and a support. The pan-tilt unit is mounted on the support, and the telescope tube is mounted on the pan-tilt unit. A display panel for displaying the angle is located on the base of the telescope tube. The steps involved in the method for monitoring the firing angle of the missile-gun coupling effect are as follows:

[0023] Step 1: According to the firing requirements, position the cannon in its designated position. Select two adjacent points, A and B, along the barrel axis on the outer surface of the muzzle and mark them for observation. Measure the distance between points A and B. Similarly, select two adjacent points, M and N, directly above the muzzle along the barrel axis and mark them for observation. Use a quadrant to adjust the firing angle to the specified angle, and rotate the azimuth mechanism to achieve the desired firing direction.

[0024] Step Two: Deploy the first electronic theodolite, designated as the side theodolite, 20 meters to the right of the gun muzzle; deploy the second electronic theodolite, designated as the rear theodolite, 20 meters directly behind the gun. The supports for both the side and rear theodolites are reliably fixed to the ground. The side theodolite monitors the firing angle, and the rear theodolite monitors the firing direction. Use a laser rangefinder to measure the distances *l* and *h* from the center of the telescope tubes of the side and rear theodolites to the measuring point at the gun muzzle, respectively. Observe from the breech towards the muzzle to distinguish left from right.

[0025] Step 3: Before firing the first round, after adjusting the firing angle and direction to the specified values ​​using the quadrant and azimuth mechanism, determine the firing angle and direction of the artillery using an electronic theodolite. The rear theodolite is aimed at points M and N on the muzzle, and the monitored firing direction is β0; the side theodolite is aimed at points A and B on the muzzle, and the monitored firing angle is α0.

[0026] When aiming the gun muzzle with the rear theodolite, the horizontal graduation line in its scope tube is adjusted to a horizontal position with the help of the pan-tilt head. When aiming the gun muzzle with the side theodolite, the horizontal graduation line in its scope tube is adjusted to be parallel to the line connecting points A and B with the help of the pan-tilt head.

[0027] The aiming value is defined as the value obtained by adjusting the firing angle and direction using a quadrant and azimuth mechanism. In a firing process of n rounds, the aiming value remains constant. The monitoring value is defined as the value obtained by determining the firing angle and direction of the artillery using an electronic theodolite. Due to thermal deformation of the artillery structure and other random factors, the monitoring value will be randomly distributed and is not constant. There is a difference between the monitoring value and the aiming value.

[0028] Step 4: Separate the impact of firing direction error on firing angle error. Following Step 3, determine the artillery firing angle and firing direction monitoring values ​​before firing the second round, and obtain the difference between the monitoring values ​​and the aiming values. Define the difference between the monitoring values ​​and the aiming values ​​as the angle error, which includes firing direction error and firing angle error.

[0029] Before firing the second round, after adjusting the firing angle and direction to the specified values ​​using the quadrant and azimuth mechanism, the rear theodolite is aimed at the muzzle, and the monitored firing direction error is β2; the side theodolite is aimed at the muzzle, and the monitored firing angle error is α2. In the right-angled triangle PMS, the trigonometric relationship is as follows:

[0030]

[0031] Solving equation (1) for x2, we have...

[0032] x2=htanβ2 (2)

[0033] In right triangle OAC, the following trigonometric relationship holds:

[0034]

[0035] Solving equation (3) for z2, we have...

[0036] z2=ltanα 20 (4)

[0037] According to the Pythagorean theorem, we have

[0038]

[0039] Using the same method, the vertical displacement y2 corresponding to point B is obtained. Based on the difference between the vertical displacements of points A and B and the distance between them, the angle error α2 is obtained using the trigonometric relationship.

[0040] Step 5: Following Step 4, determine the firing direction error and firing angle error from the 3rd to the nth bullet.

[0041] Step Six: After a group of projectiles has completed firing, analyze the relationship between the angle of fire error, the direction of fire error, and the coordinates of the projectile's impact point to determine whether the firing density is related to the monitoring values ​​of the angle of fire and the direction of fire, and what the influencing patterns are.

[0042] When artillery fires, the errors in firing angle and direction are very small, generally less than 1 degree. Therefore, the same result can be obtained by using the relationship between arc length, circle radius, and central angle in the derivation of the above formula.

[0043] The difference between the monitored values ​​of the launch angle and trajectory of the nth projectile and those of the first projectile is defined as the launch angle error and trajectory error of the nth projectile.

Claims

1. A method for monitoring the firing angle of a projectile-gun coupling effect, characterized in that, The method for monitoring the firing angle of the missile-gun coupling effect involves an electronic theodolite, a quadrant, and a laser rangefinder. Two electronic theodolites are used; each has orthogonal crosshairs, one horizontal and one vertical, for observing the position of the measuring point. The electronic theodolite also includes a pan-tilt unit and a support. The pan-tilt unit is mounted on the support, and the firing tube is mounted on the pan-tilt unit. The base of the firing tube has a display panel for showing the angle. The steps involved in the method for monitoring the firing angle of the missile-gun coupling effect are as follows: Step 1: According to the firing requirements, position the cannon in the gun position, select two adjacent points A and B on the outer side of the muzzle along the barrel axis, make observation marks, and measure the distance between points A and B; Using the same principle, select two adjacent points, M and N, directly above the outer surface of the muzzle along the barrel axis and mark them for observation; use a quadrant to adjust the firing angle to the specified angle, and rotate the azimuth mechanism to make the firing direction to the specified angle; Step 2: Deploy the first electronic theodolite 20 meters to the right of the gun muzzle, designated as the side theodolite; deploy the second electronic theodolite 20 meters directly behind the gun, designated as the rear theodolite; secure the supports of the side and rear theodolites to the ground; the side theodolite monitors the firing angle, and the rear theodolite monitors the firing direction; use a laser rangefinder to measure the distances l and h from the center of the telescope tube of the side and rear theodolites to the measuring point at the gun muzzle; observe from the breech towards the muzzle to distinguish left from right; Step 3: Before firing the first round, after adjusting the firing angle and direction to the specified values ​​using the quadrant and azimuth mechanism, determine the firing angle and direction before firing using an electronic theodolite; then aim the theodolite at points M and N on the muzzle and monitor the obtained firing direction as β0. The theodolite was aimed at points A and B at the muzzle, and the monitored firing angle was α0. When aiming the gun muzzle with the rear theodolite, the horizontal scale line in its scope tube is adjusted to a horizontal state with the help of the gimbal; when aiming the gun muzzle with the side theodolite, the horizontal scale line in its scope tube is adjusted to be parallel to the line connecting points A and B with the help of the gimbal. The aiming value is defined as the value obtained by adjusting the firing angle and direction using a quadrant and azimuth mechanism. In a firing process of n rounds, the aiming value remains constant. The monitoring value is defined as the value obtained by determining the firing angle and direction using an electronic theodolite. Due to thermal deformation of the artillery structure and other random factors, the monitoring value will be randomly distributed and is not constant. There is a difference between the monitoring value and the aiming value. Step 4: Separate the influence of firing direction error on firing angle error; Following Step 3, determine the firing angle and firing direction monitoring values ​​before firing the second round, and obtain the difference between the monitoring value and the aiming value; Define the difference between the monitoring value and the aiming value as the angle error; The angle error involves firing angle error and firing direction error; Before firing the second round, after adjusting the firing angle and direction to the specified values ​​using the quadrant and azimuth mechanism, the theodolite was then aimed at the muzzle, and the monitored firing error was β2. The theodolite is aimed at the gun muzzle, and the monitored values ​​are processed to obtain the firing angle error α2; in the right triangle PMS, there is a trigonometric relationship: Solving equation (1) for x2, we have... x2=htanβ2 (2) In right triangle OAC, the following trigonometric relationship holds: Solving equation (3) for z2, we have... z2=ltanα 20 (4) Where α 20 These are direct observations from the theodolite, which include the influence of azimuth error; According to the Pythagorean theorem, the vertical displacement of point A is... The vertical displacement corresponding to point B was obtained using the same method. Based on the difference in vertical displacement between points A and B and the distance between them, the angle of incidence error α2 can be obtained using the trigonometric relationship. Step 5: Following Step 4, determine the firing direction error and firing angle error from the 3rd to the nth bullet; Step Six: After a group of n bullets has been fired, analyze the relationship between the angle of fire error, the direction of fire error and the coordinates of the bullet impact point, and determine whether the firing density is related to the monitoring values ​​of the angle of fire and the direction of fire, and what the influencing patterns are.

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