External ballistic parameter measuring device and measuring method based on electric field sensor array

Abstract

The invention relates to the technical field of cannonball outer trajectory measurement, in particular to an outer trajectory parameter measuring device and method based on an electric field sensor array. The system comprises a detection array composed of four electric field sensors. The method comprises the following steps: according to an electric field intensity change rate detected by an electric field sensor when a charged projectile flies nearby the electric field sensor, establishing each parameter relational expression by combining a Coulomb law; and carrying out indirect measurement on the position and the speed of the charged projectile according to the calibration and speed calibration equation. According to the invention, the electric field sensor is used for non-contact measurement of outer ballistic parameters based on the electrostatic detection technology, no interference is caused to the projectile, the cost is low, and the operation is simple; the device is high in adaptability, can be suitable for various different measurement environments, and is wide in application range.

Description

Technical Field

[0001] The present invention relates to the technical field of external ballistic measurement of projectiles, and specifically to an external ballistic parameter measurement device and method based on an electric field sensor array. Technical Background

[0002] The methods for measuring the external ballistics of projectiles include contact measurement and non-contact measurement. With the development of sensor technology and data processing capabilities, non-contact measurement technology has received increasing attention. Especially in the military field, the measurement of external ballistic parameters of projectiles has extended from physical targets such as wooden targets and steel targets to virtual target surfaces such as light screen targets, electromagnetic targets, and acoustic targets. However, there is currently no method for measuring the external ballistic parameters of projectiles based on the principle of electrostatic detection.

[0003] In the literature with the publication number "CN106054256A", a method for non-contact tracking and detecting a moving charge source is disclosed. This method realizes the positioning operation of the moving charge by constructing a multi-pole plate detection array. It can be found that the problems it has are as follows: 1. When the multi-pole plate array detects the moving charge source, only its position information can be obtained, and its velocity characteristics cannot be obtained simultaneously; 2. This method needs to process the output voltage signal to obtain the charge amount on the plate, and the processing process is complex and cumbersome, and it is easy to generate systematic errors. In the solution given by Vinci S, Zhu J, Hull D. Analysis of electrostatic charge on small-arms projectiles [C] / / Active and Passive Signatures III. SPIE, 2012, 8382: 163-173., the static charge analysis of small-arms projectiles is carried out by using an electric field sensor. The measurement of the charge amount of the projectile is mainly realized by combining the relationship between the output voltage of the D-dot sensor and the change rate of the electric field strength with Coulomb's law. This sensor has good real-time performance and small distortion, and the design cost of the sensor is relatively low compared with other non-contact electrostatic detectors. However, it has the drawback that it cannot track the motion characteristics of the projectile.

[0004] In the current methods for non-contact measurement of external ballistic parameters of projectiles, when using a light screen target for measurement, stable beam projection is required, and the light screen target is very sensitive to the reflection characteristics of the target surface of the object to be measured. If there is a reflective material on the target surface, it may lead to measurement errors. When using an electromagnetic target for measurement, electromagnetic waves attenuate rapidly in the air, and it is difficult to realize the measurement of the target hitting of the projectile. When using an acoustic target for measurement, it is extremely dependent on the working environment and is greatly affected by factors such as wind speed and temperature, and it is only applicable to hypersonic projectiles. Whether it is a light screen target, an electromagnetic target, or a sound speed target, they are all costly to operate and are a limiting factor in military projects.

[0005] In summary, continuously optimizing the method for measuring external ballistic parameters based on an electric field sensor array has become a key research direction for scientific researchers in this field. Summary of the Invention

[0006] The object of the present invention is to provide a device and method for measuring external ballistic parameters based on an electric field sensor array, so as to realize the measurement of various parameters during the external ballistic flight of a projectile through non-contact electrostatic detection of the charged projectile, and overcome the problems of single detection information of the projectile motion characteristics and high operation cost existing in the prior art.

[0007] To achieve the above object, the present invention provides the following technical solutions: A device and method for measuring external ballistic parameters based on an electric field sensor array, including the following steps:

[0008] An external ballistic parameter measurement device based on an electric field sensor array, comprising a detection array composed of four electric field sensors, characterized in that: one of the electric field sensors, denoted as a, serves as a reference coordinate electric field sensor and is installed on the measurement plane as the origin of the reference coordinate system, and the remaining three electric field sensors, denoted as b, c, and d respectively, serve as three-axis positioning electric field sensors.

[0009] A measurement method for an external ballistic parameter measurement device based on an electric field sensor array, including the following steps:

[0010] Step 1: According to the measurement principle of the electric field sensor and in combination with Coulomb's law, obtain the electrostatic detection formula of the electric field sensor;

[0011] Step 2: The projectile is fired horizontally, and timing starts when the firing is triggered;

[0012] Step 3: Record the moments when passing near sensors a, c, and d, and the output voltages of the sensors at these moments;

[0013] Step 4: Record the moment when the output voltage of sensor b is the same as the output voltage of sensor a;

[0014] Step 5: Calculate the flight speed of the projectile along the firing direction according to the recorded time intervals;

[0015] Step 6: Substitute the output voltages of sensors a, c, and d into the calibration equation to solve for the coordinate position of the projectile.

[0016] Preferably, in step 1, the electrostatic detection formula of the electric field sensor is obtained in combination with Coulomb's law, and its mathematical expression:

[0017]

[0018] In the formula: A effis the effective area of the electric field sensor; g is the acceleration due to gravity; q is the charge of the projectile; t is the time for the projectile to travel from the firing point to the measurement point; v is the flight speed of the projectile; z is the z-axis coordinate of the world coordinate system with the electric field sensor as the origin of the coordinate system, the x-axis direction as the flight direction of the projectile, and the z-axis direction as the normal direction of the measurement plane; y is the y-axis coordinate of the world coordinate system; V out is the output voltage of the electric field sensor.

[0019] Preferably, in the fifth step, the velocity of the projectile along the firing direction is calculated according to the time interval between the two records, and its calculation expression is:

[0020]

[0021] In the formula: x 0 is the x-axis position of sensor b in the reference coordinate system; t 1 is the time when sensors a, c, and d are first recorded; t 2 is the time when sensor b is second recorded.

[0022] Preferably, in the sixth step, according to the output voltages of sensors a, c, and d, substituting them into the calibration equation to determine 5,

[0023] the coordinates y and z of the projectile in the reference coordinate system, and the mathematical expression of its calibration equation is:

[0024]

[0025] In the formula: t 1 is the time for the projectile to travel from the firing point to the first recorded time; v is the flight speed of the projectile; z is the z-axis coordinate of the projectile on the reference coordinate system composed of the electric field sensor a as the origin of the reference coordinate system, the x-axis direction as the flight direction of the projectile, and the z-axis direction as the normal direction of the measurement plane; z 0 is the z-axis coordinate of sensor d in the reference coordinate system; y is the y-axis coordinate of the projectile in the reference coordinate system; y 0 is the y-axis coordinate of sensor c in the reference coordinate system; V outa is the output voltage of sensor a; V outc is the output voltage of sensor c; V outd is the output voltage of sensor d; α, β are voltage proportionality coefficients.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] 1. The present invention provides a device for measuring the external ballistic parameters of a projectile based on the principle of electrostatic detection. The known non-contact methods for measuring external ballistic parameters mainly use light screen targets, electromagnetic targets, and acoustic targets for measurement. Their installation and maintenance require highly professional equipment and technology, the operation is relatively complex, and they rely on professional equipment support. There is a lack of a method for measuring the external ballistic parameters of a projectile based on electrostatic detection. The device of the present invention is a four-electric-field sensor array, which can measure the position information and velocity information of a charged projectile, with a large number of measured parameters and simple operation.

[0028] 2. Based on the independently designed device, the present invention utilizes the self-measurement principle of the electric-field sensor combined with Coulomb's law to obtain the relationship between position, time, velocity, and charge quantity. Then, a four-electric-field sensor array is designed to realize the measurement of the external ballistic parameters of a flying projectile based on electrostatic detection technology. The present invention uses four electric-field sensors to form a detection array to perform electrostatic detection on a flying projectile, and then combines the calibration formula and the velocity measurement formula to realize the measurement of the external ballistic parameters of the projectile. It can be seen from the calibration formula that this method does not need to consider the electrostatic charge quantity of the projectile during the measurement process, and it has high accuracy and good anti-interference performance. Compared with the multi-plate detection array in the entire electrostatic detection process of the present invention, while measuring the position of the projectile, the measurement of its velocity is also incorporated, making the acquisition of external ballistic parameters more comprehensive.

[0029] 3. The present invention has strong applicability. Since the electric-field sensor in the system is only affected by the change in the electric-field intensity caused by the measurement target, it can adapt to a variety of different measurement environments and conditions, is non-invasive to the measurement target, and has a wide range of applications. It can be applied to both military and civilian fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the layout of the detection unit of the present invention;

[0031] Figure 2 It is a schematic diagram of the measurement principle of the electric-field sensor under the action of the measurement plane of the present invention;

[0032] Figure 3 It is a schematic diagram of the relative position between the projectile and the electric-field sensor. DETAILED DESCRIPTION OF THE INVENTION

[0033] The following further clearly and completely describes the present invention with reference to the drawings in the specific embodiments of the present invention. This specific embodiment is only used to explain the present invention and is not used to limit the present invention.

[0034] See Figure 1, the present invention provides an external ballistic parameter measurement device based on an electric field sensor array, including a detection array composed of four electric field sensors, characterized in that: one of the electric field sensors, denoted as a, serves as a reference coordinate electric field sensor and is installed on the measurement plane as the origin of the reference coordinate system, and the remaining three electric field sensors, denoted as b, c, and d respectively, serve as three-axis positioning electric field sensors.

[0035] A measurement method for an external ballistic parameter measurement device based on an electric field sensor array includes the following steps:

[0036] Step 1: Refer to Figure 2 , according to the measurement principle of the electric field sensor and in combination with Coulomb's law, the electrostatic detection formula of the electric field sensor is obtained. The mathematical expression of the electrostatic detection formula of the electric field sensor is:

[0037]

[0038] In the formula: A eff is the effective area of the electric field sensor; g is the acceleration due to gravity; q is the charge of the projectile; t is the time for the projectile to travel from the shooting point to the measurement point; v is the flight speed of the projectile; z is the z-axis coordinate of the world coordinate system formed with the origin of the coordinate system of the electric field sensor, the x-axis direction being the flight direction of the projectile and the z-axis direction being the normal direction of the measurement plane; y is the y-axis coordinate of the world coordinate system; V out is the output voltage of the electric field sensor.

[0039] Step 2: The projectile is fired horizontally and timing starts when the shooting is triggered;

[0040] Step 3: Record the moments when passing by sensors a, c, and d, and the output voltages of the sensors at those moments;

[0041] Step 4: Record the moment when the output voltage of sensor b is the same as that of sensor a;

[0042] Step 5: Calculate the flight speed of the projectile along the shooting direction according to the recorded time intervals:

[0043] Calculate the speed of the projectile along the shooting direction according to the time intervals recorded twice. The calculation expression is:

[0044]

[0045] In the formula: x 0 is the x-axis position of sensor b in the reference coordinate system; t 1 is the moment when sensors a, c, and d are first recorded; t 2 is the moment when sensor b is second recorded.

[0046] Step 6: Refer to Figure 3, according to the output voltages of sensors a, c, and d, substitute them into the calibration equation to solve for the projectile coordinate position:

[0047] The coordinates of the projectile in the reference coordinate system are y and z, and the mathematical expression of its calibration equation is:

[0048]

[0049] In the formula: t 1 is the time from the shooting point to the first recording time of the projectile; v is the flight speed of the projectile; z is the z-axis coordinate of the projectile in the reference coordinate system formed with the origin of the electric field sensor a as the origin of the reference coordinate system, the x-axis direction as the flight direction of the projectile, and the z-axis direction as the normal direction of the measurement plane; z 0 is the z-axis coordinate of sensor d in the reference coordinate system; y is the y-axis coordinate of the projectile in the reference coordinate system; y 0 is the y-axis coordinate of sensor c in the reference coordinate system; V outa is the output voltage of sensor a; V outc is the output voltage of sensor c; V outd is the output voltage of sensor d; α, β are voltage proportionality coefficients.

[0050] The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An external ballistic parameter measurement device based on an electric field sensor array, comprising a detection array composed of four electric field sensors, characterized in that: One of the electric field sensors, denoted as a, is used as a reference coordinate electric field sensor and is installed on the measurement plane as the origin of the reference coordinate system. The remaining three electric field sensors, denoted as b, c, and d, are used as three-axis positioning electric field sensors.

2. A method for measuring an external ballistic parameter measurement device based on an electric field sensor array, characterized in that: The following steps are involved: Step 1: Based on the measurement principle of the electric field sensor and combined with Coulomb's law, the electrostatic detection formula of the electric field sensor is obtained; Step 2: The projectile is fired in a horizontal direction, and the timing starts when the firing is triggered; Step 3: Record the time when the sensor passes near sensors a, c, and d, and the output voltage of the sensors at that time; Step 4: Record the moment when the output voltage of sensor b is the same as the output voltage of sensor a; Step 5: Calculate the flying speed of the projectile along the shooting direction according to the recorded time interval; Step 6: Substitute the output voltages of sensors a, c, and d into the calibration equation to solve for the projectile coordinate position.

3. The measuring method of the exterior ballistic parameter measuring device based on the electric field sensor array according to claim 2 is characterized in that: In step 1, the electrostatic detection formula of the electric field sensor is obtained by combining Coulomb's law, and its mathematical expression is: Where: A eff is the effective area of ​​the electric field sensor; g is the acceleration of gravity; q is the charge of the projectile; t is the time it takes for the projectile to travel from the shooting point to the measuring point; v is the projectile flight speed; z is the z-axis coordinate of the world coordinate system composed of the electric field sensor as the origin of the coordinate system, the x-axis direction as the projectile flight direction, and the z-axis direction as the normal direction of the measurement plane; y is the y-axis coordinate of the world coordinate system; V out is the output voltage of the electric field sensor.

4. The measuring method of the external ballistic parameter measuring device based on the electric field sensor array according to claim 2 is characterized in that: In step 5, the speed of the projectile along the shooting direction is calculated according to the time interval between the two records, and the calculation expression is: Where: x0 is the x-axis position of sensor b in the reference coordinate system; t1 is the time when sensors a, c, and d are recorded for the first time; t2 is the time when sensor b is recorded for the second time.

5. The measuring method of the external ballistic parameter measuring device based on the electric field sensor array according to claim 2 is characterized in that: In step 6, the output voltages of sensors a, c, and d are brought into the calibration equation to determine the coordinates y and z of the projectile in the reference coordinate system. The mathematical expression of the calibration equation is: Where: t1 is the time from the shooting point to the first recording of the projectile; v is the flight speed of the projectile; z is the z-axis coordinate of the projectile in the reference coordinate system composed of the electric field sensor a as the origin of the reference coordinate system, the x-axis direction as the projectile flight direction, and the z-axis direction as the normal direction of the measurement plane; z0 is the z-axis coordinate of sensor d in the reference coordinate system; y is the y-axis coordinate of the projectile in the reference coordinate system; y0 is the y-axis coordinate of sensor c in the reference coordinate system; V outa is the output voltage of sensor a; V outc is the output voltage of sensor c; V outd is the output voltage of sensor d; α and β are voltage proportional coefficients.

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