Simulated hand grenade and flight path measurement method

Abstract

The invention provides a simulated hand grenade and a flight path measuring method. The simulated hand grenade comprises a shell, a safety pin, a safety pin switch, a three-axis acceleration sensor, a three-axis magnetic compass, an air pressure sensor, a microprocessor and a wireless communication unit; the three-axis acceleration sensor, the three-axis magnetic compass and the air pressure sensor are electrically connected with the microprocessor; the wireless communication unit is electrically connected with the microprocessor; the safety pin switch is electrically connected with the microprocessor; the safety pin is mechanically connected with the safety pin switch; the problem that the simulated damage effect is distorted due to the fact that the distance between the explosion point and a person cannot be accurately judged through an existing simulated hand grenade is solved, the position of the explosion point of the simulated hand grenade can be more accurately obtained through the simulated hand grenade and the flight path measuring method, and the damage effect of the hand grenade can be more vividly simulated; the training quality is improved, and data support is provided for more refined training and assessment.

Description

Technical Field

[0001] The invention relates to a simulated hand grenade and a flight trajectory measurement method. Background Art

[0002] At present, live-fire confrontation training is developing in the direction of intelligence, and simulation equipment is often used in drills to replace actual weapons and equipment. Direct-aiming weapons usually use lasers instead of ammunition for live-fire confrontation training. The specific method is to install a laser transmitter on the weapon and install a laser decoding device on the personnel and equipment. During confrontation training, the weapon emits a coded laser beam. If the laser decoding device installed on the personnel and equipment receives the coded laser beam, it is judged to be hit. Indirect-aiming weapons usually use data to conduct live-fire confrontation training. The control center calculates the landing point of the shell based on the firing data of the artillery and makes decisions on the personnel and equipment within the damage range. Grenade is a weapon for close combat of the troops. The simulation method usually used is to simulate the explosion effect by sending out a wireless radio frequency signal when the delay fuse timing ends. The surrounding personnel and equipment will produce corresponding damage simulation after receiving the wireless signal.

[0003] The current simulated grenades have the following problems:

[0004] 1. Inconsistent with the damaging effect of actual grenades: The damaging effect of actual grenades depends on the distance between the explosion point and the personnel. The closer the distance, the greater the probability of personnel being hit by grenade fragments, and the more serious the injury; the farther the distance, the smaller the probability of personnel being hit by grenade fragments, and the lighter the injury. However, the wireless radio frequency signal simulated by the grenade is greatly affected by the signal power and antenna direction. After receiving the wireless radio frequency signal, personnel and equipment cannot accurately obtain the distance between the grenade explosion point. Therefore, the method of simulating grenade explosions through wireless radio frequency signals cannot accurately simulate the actual damaging effect of grenades, which makes the confrontation training seriously inconsistent with actual combat and seriously affects the effect of confrontation training.

[0005] 2. The patent "TW201520507A_Grenade Throwing Training System" uses a satellite positioning module installed on the grenade to determine the coordinate position of the grenade explosion point. This solution has serious defects: the positioning principle of the satellite positioning module is to use the antenna to receive the positioning signals of multiple Beidou or GPS satellites in the sky to calculate the current coordinates. Only when the antenna can stably receive signals from multiple satellites can it achieve positioning more accurately. If the number of satellites received by the antenna is too small or the signal is unstable, a very large positioning error will occur, and the positioning error may reach hundreds of meters or even kilometers. Because the satellite signal is very weak, an upward directional antenna is usually used to obtain the positioning signal. The simulated grenade will roll in the air after being thrown, and the direction of the directional antenna will change continuously. It will be impossible to stably receive the satellite positioning signal, and basically it is impossible to achieve satellite positioning, so it is impossible to accurately determine the location of the grenade explosion point. Summary of the invention

[0006] Purpose of the invention: The purpose of the present invention is to solve the problem that the existing simulated hand grenade cannot accurately measure the distance between the explosion point and the person, resulting in the inconsistency between the damage simulation and the damage effect of the actual hand grenade. The present invention provides a simulated hand grenade and a flight trajectory measurement method.

[0007] The simulated grenade comprises a shell, a safety pin, a safety pin switch, a three-axis acceleration sensor, a three-axis magnetic compass, an air pressure sensor, a microprocessor and a wireless communication unit.

[0008] The three-axis acceleration sensor, the three-axis magnetic compass, and the air pressure sensor are electrically connected to the microprocessor; the wireless communication unit is electrically connected to the microprocessor; and the safety pin switch is electrically connected to the microprocessor.

[0009] The safety pin is mechanically connected to the safety pin switch. After the safety pin is pulled out, the safety pin switch is actuated to output a switch signal to the microprocessor.

[0010] The three-axis acceleration sensor is used to measure the initial velocity of the grenade when it is thrown; the three-axis magnetic compass is used to measure the direction of the grenade when it is thrown; the air pressure sensor is used to measure the highest point of the grenade's flight trajectory; and the wireless communication unit is used to receive the current position information of the thrower or output grenade explosion information to the outside.

[0011] In order to achieve the purpose of the present invention, a method for measuring a simulated grenade flight trajectory is also disclosed, comprising the following steps:

[0012] Step 1: Before throwing a grenade, the thrower first pulls out the safety pin to activate the safety pin switch and output a switch signal to the microprocessor.

[0013] The microprocessor records the moment when the safety pin is pulled out, which is used to measure and calculate the initial velocity V of the throw. 0 The start time of

[0014] The microprocessor obtains the current position information of the throwing person;

[0015] The microprocessor starts the three-axis acceleration sensor and starts to continuously collect three-axis acceleration data a x ,a y ,a z ;

[0016] The microprocessor starts the three-axis magnetic compass and starts to continuously collect three-axis magnetic compass data m x ,m y ,m z ;

[0017] Step 2: During the grenade throwing process, as the arm swings, the grenade is acted upon by force, and the three-axis acceleration sensor outputs the three-axis acceleration data to the microprocessor in real time. The microprocessor integrates the three-axis acceleration to obtain the instantaneous velocity of the grenade at each time point in the throwing process. The coordinate position of the grenade when it is thrown is recorded as x 0 ,y 0 ,z 0 , the time when the grenade is thrown is recorded as t 0 , the time involved in the subsequent steps is t 0 Moments as a time reference;

[0018] Step 3: During the flight of the grenade, the microprocessor collects the value of the air pressure sensor in real time at a time interval of ΔT. The time when the air pressure sensor value is the minimum is the time t when the grenade reaches the highest point. h ;

[0019] Step 4: Calculate the vertical component V of the grenade's velocity when it is thrown v and the horizontal component V h ;

[0020] Step 5: Calculate the grenade's flight trajectory:

[0021] The relationship between the grenade's flying position x, y, z and flight time t in the air is as follows:

[0022] x=x 0 +V h ×t×cosA 0 ,

[0023] y=y 0 +V h ×t×sinA 0 ,

[0024]

[0025] Step 6: If the fuse delay time ends during the grenade flight, replace t in the formula of step 5 with the fuse delay time t e Substitute in the numbers and calculate the position of the grenade in the air when it explodes;

[0026] Step 7: When the absolute value of the grenade's total acceleration is greater than g, it means the grenade has landed. Record the landing time t d , replace t in the formula of step 5 with the landing time t d Substitute in and calculate the location of the grenade landing point, where g is the gravitational acceleration constant;

[0027] Step 8: When the grenade fuse delay ends, the wireless communication unit transmits the explosion point location information calculated by the microprocessor.

[0028] Step 2 includes: when the grenade is thrown, without considering the air resistance, the grenade is only affected by gravity, and the total acceleration is about 0. Therefore, the microprocessor can determine the time point t when the grenade is thrown according to the characteristic that the total acceleration is about 0. 0 , use the following formula to calculate the time t when the grenade is thrown 0 The speed value V of its three axes x 、V y 、V z :

[0029]

[0030]

[0031]

[0032] Use the following formula to calculate the grenade's 0 The initial velocity V at the moment of being thrown 0 :

[0033]

[0034] Place the grenade at t 0 The three-axis magnetic compass data at the time of being thrown is recorded as Using the three-axis magnetic compass data and the deviation value of the actual throwing direction, the actual throwing direction A of the grenade is obtained. 0 , and record the pressure sensor at the time t when the grenade is thrown 0 The air pressure value P 0 ;

[0035] The moment the grenade is thrown, the simulated fuse is activated and the fuse timing begins.

[0036] In step 2, the three-axis magnetic compass data and the deviation value of the actual throwing direction are obtained by having the thrower repeatedly throw the grenade for multiple times and then measuring and counting.

[0037] In step 2, the coordinate position of the grenade when it is thrown is approximately replaced by the position information of the thrower when it is thrown.

[0038] Step 3 includes: recording the current air pressure sensor value as P t , the pressure sensor value collected at the previous moment is recorded as P t-ΔT , when P t <P t-ΔT , it is judged that the grenade is still in the rising stage; when P t >P t-ΔT , then the grenade is judged to be in the falling stage; record the first occurrence of P t >Pt-ΔT Time t h0 , t h0 -ΔT is the time t when the grenade flies to the highest point h .

[0039] In step 4, the vertical component V of the grenade's velocity at the moment it is thrown is calculated using the following formula: v and the horizontal component V h , where g is the gravitational acceleration constant:

[0040] V v =g·t h ,

[0041]

[0042] The present invention also provides a storage medium storing a computer program or instruction. When the computer program or instruction is executed, the method for measuring the flight trajectory of a simulated grenade is implemented.

[0043] Beneficial effect: The present invention solves the problem that the simulated grenade cannot accurately judge the distance between the explosion point and the personnel, resulting in distortion of the simulated damage effect. The simulated grenade and the flight trajectory measurement method can more accurately obtain the position of the simulated grenade explosion point, and can more realistically simulate the damage effect of the grenade, improve the training quality, and provide data support for more refined training and assessment. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0045] Figure 1 This is a schematic diagram of the appearance of a simulated grenade.

[0046] Figure 2 This is a schematic diagram of a simulated grenade structure.

[0047] Figure 3 Schematic diagram of the grenade's flight trajectory.

[0048] Figure 4 The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0049] like Figure 1 and Figure 2 As shown, the present invention provides a simulated grenade, including a shell 1, a safety grip 2, a safety pin 3, a safety pin switch 4, a three-axis acceleration sensor 5, a three-axis magnetic compass 6, an air pressure sensor 7, a microprocessor 8 and a wireless communication unit 9.

[0050] The shell 1 consists of two parts, left and right, which are connected by screws. The shape of the shell 1 is exactly the same as that of a traditional hand grenade.

[0051] The safety pin 3 crosses the housing 1 and presses the reed of the safety pin switch 4, so that the safety pin switch 4 is in an open state. When the thrower pulls out the safety pin 3, the reed of the safety pin switch 4 is released, so that the safety pin switch 4 is in a closed state. The safety pin switch 4 can be a micro switch.

[0052] A three-axis acceleration sensor 5 , a three-axis magnetic compass 6 , an air pressure sensor 7 , a microprocessor 8 , and a wireless communication unit 9 are installed inside the housing 1 .

[0053] The three-axis acceleration sensor 5 is used to measure the initial velocity of the grenade when it is thrown; the three-axis magnetic compass 6 is used to measure the direction of the grenade when it is thrown; the air pressure sensor 7 is used to measure the highest point of the grenade's flight trajectory, and the wireless communication unit 9 is used to receive the current position information of the thrower or output the grenade explosion information to the outside. The three-axis acceleration sensor 5, the three-axis magnetic compass 6, the air pressure sensor 7 are electrically connected to the microprocessor 8; the wireless communication unit 9 is electrically connected to the microprocessor 8; the safety pin switch 4 is electrically connected to the microprocessor 8. The three-axis acceleration sensor 5 can use the MEMS chip of the LIS2DH12TR model, the three-axis magnetic compass 6 can use the MEMS chip of the LIS2MDL model, the air pressure sensor 7 can use the BMP280 chip, the microprocessor 8 can use the STM32F4 series ARM chip, and the wireless communication unit 9 can use the Zigbee communication module or the Bluetooth communication module.

[0054] The magnetic compass 5 is used to measure the direction angle of the grenade body. Usually, when throwing a grenade, the thrower holds the grenade safety grip 2 with the thumb, with the base of the thumb facing outward. Due to the consistency of individual throwing habits, the deviation value of the direction angle of the grenade body and the throwing direction angle at the moment of throwing the grenade is basically the same. The deviation value can be obtained by letting the thrower repeatedly throw the grenade for measurement and statistics. The statistical measurement method is a conventional means, so it will not be described in detail in this technical solution. The throwing direction of the grenade can be calculated based on the direction angle of the grenade body at the moment of throwing the grenade and the deviation value.

[0055] Figure 3 The figure shows a schematic diagram of the grenade's flight trajectory. The X-axis in the figure is the due east direction of the geodetic coordinate system, the Y-axis is the due north direction, and the Z-axis is upward.

[0056] 1. The throwing person is at the geographic coordinates (x 0 ,y 0 ,z 0 ) to throw a grenade, first pull out the safety pin 3, so that the safety pin switch 4 is actuated, and the switch signal is output to the microprocessor 8.

[0057] The microprocessor 8 records the moment when the safety pin 3 is pulled out as a time for measuring and calculating the initial velocity V of the throw. 0 The start time of the .

[0058] Since the throwing person is equipped with a positioning module, the simulated grenade can obtain the current position information of the throwing person through the Zigbee or Bluetooth wireless communication unit and transmit it to the microprocessor 8. The microprocessor 8 converts the geographic coordinates (x 0 ,y 0 ,z 0 ) as the initial position of the grenade when it is thrown.

[0059] The microprocessor 8 starts the three-axis acceleration sensor 5 and starts to continuously collect three-axis acceleration data a x ,a y ,a z .

[0060] The microprocessor 8 starts the three-axis magnetic compass 6 and starts to continuously collect the three-axis magnetic compass data m x ,m y ,m z .

[0061] 2. The microprocessor 8 can obtain the instantaneous speed of the three axes of the grenade at each time point during the throwing process by integrating the three-axis acceleration.

[0062] The microprocessor 8 can determine the time point when the grenade is thrown based on the characteristic that the combined acceleration is about 0, which is recorded as t 0 The grenade throwing time t can be calculated using the following formula 0 The speed values ​​of its three axes are:

[0063]

[0064]

[0065]

[0066] Grenade in t 0 The initial velocity V at the moment of being thrown 0 It can be calculated using the following formula:

[0067]

[0068] Place the grenade at t 0 The three-axis magnetic compass data at the time of being thrown is recorded and recorded as Using the three-axis magnetic compass data and the deviation value of the actual throwing direction, the actual throwing direction A of the grenade can be obtained. 0 . Record the pressure sensor 7 at the time t when the grenade is thrown 0 The air pressure value P0 .

[0069] The moment the grenade is thrown, the simulated fuse is activated and the fuse timing begins.

[0070] 3. During the flight of the grenade, the microprocessor 8 collects the value of the air pressure sensor 7 in real time at a time interval of ΔT, and the current air pressure sensor value is recorded as P t , the pressure sensor value collected at the previous moment is recorded as P t-ΔT , when P t <P t-ΔT , it is judged that the grenade is still in the rising stage; when P t >P t-ΔT , then the grenade is judged to be in the falling stage. Record the first occurrence of P t >P t-ΔT Time t h0 , t h0 -ΔT is the time t when the grenade flies to the highest point h .

[0071] 4. Calculate the vertical component V of the grenade's velocity when it is thrown v and the horizontal component V h :

[0072] V v =g·t h ;

[0073]

[0074] 5. The method for calculating the aerial flight trajectory of a grenade is as follows:

[0075] The relationship between the grenade's flying position x, y, z and flight time t in the air is as follows:

[0076] x=x 0 +V h ×t×cosA 0 ;

[0077] y=y 0 +V h ×t×sinA 0 ;

[0078]

[0079] 6. If the fuse delay time ends during the grenade's flight, replace the fuse delay time t in the grenade's air trajectory calculation formula with the grenade's air trajectory calculation formula t. e Substituting this in, we can calculate the position of the grenade in the air when it explodes.

[0080] 7. When the absolute value of the grenade's total acceleration is greater than g, it means that the grenade has landed. Record the landing time t d . Replace the t in the formula for calculating the grenade's aerial trajectory with the landing time t d Substituting this into the equation, we can calculate the location of the grenade landing point. Where g is the gravitational acceleration constant.

[0081] 8. At the end of the grenade fuse delay, the wireless communication unit 9 transmits the explosion point location information calculated by the microprocessor. After receiving the explosion point location information, the personnel around the explosion point calculate the distance between them and the explosion point in combination with their own location information, and perform damage calculation. Personnel damage calculation is a common method in actual military training, so it will not be described in detail in this technical solution.

[0082] Figure 4 The figure is a flow chart of the method for measuring the simulated grenade flight trajectory.

[0083] The present invention provides a method for simulating a hand grenade and measuring its flight trajectory. There are many methods and approaches to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims

1. A simulated grenade, characterized in that: It includes a housing, a safety pin, a safety pin switch, a three-axis acceleration sensor, a three-axis magnetic compass, an air pressure sensor, a microprocessor and a wireless communication unit; The three-axis acceleration sensor, the three-axis magnetic compass, and the air pressure sensor are electrically connected to the microprocessor; the wireless communication unit is electrically connected to the microprocessor; and the safety pin switch is electrically connected to the microprocessor; The safety pin is mechanically connected to the safety pin switch. When the safety pin is pulled out, the safety pin switch is actuated to output a switch signal to the microprocessor. The three-axis acceleration sensor is used to measure the initial velocity of the grenade when it is thrown; the three-axis magnetic compass is used to measure the direction of the grenade when it is thrown; the air pressure sensor is used to measure the highest point of the grenade's flight trajectory; and the wireless communication unit is used to receive the current position information of the thrower or output grenade explosion information to the outside.

2. A method for measuring a simulated grenade flight trajectory, characterized in that: The following steps are involved: Step 1: Before throwing the grenade, the thrower first pulls out the safety pin to activate the safety pin switch and outputs the switch signal to the microprocessor; The microprocessor records the moment of pulling out the safety pin as the starting time for measuring and calculating the initial velocity V0 of the throw; The microprocessor obtains the current position information of the throwing person; The microprocessor starts the three-axis acceleration sensor and starts to continuously collect three-axis acceleration data a x ,a y ,a z ; The microprocessor starts the three-axis magnetic compass and starts to continuously collect three-axis magnetic compass data m x ,m y ,m z ; Step 2: During the grenade throwing process, as the arm swings, the grenade is acted upon by force, and the three-axis acceleration sensor outputs the three-axis acceleration data to the microprocessor in real time. The microprocessor integrates the three-axis acceleration to obtain the instantaneous speed of the grenade at each time point in the three axes during the throwing process; the coordinate position of the grenade when it is thrown is recorded as x0, y0, z0, and the time point when the grenade is thrown is recorded as t0. The time involved in the subsequent steps is based on the time t0; Step 3: During the flight of the grenade, the microprocessor collects the value of the air pressure sensor in real time at a time interval of ΔT. The time when the air pressure sensor value is minimum is the time t when the grenade reaches the highest point. h ; Step 4: Calculate the vertical component V of the grenade's velocity when it is thrown v and the horizontal component V h ; Step 5: Calculate the grenade's flight trajectory: The relationship between the grenade's flying position x, y, z and flight time t in the air is as follows: x=x0+V h ×t×cosA0, y=y0+V h ×t×sinA0, Step 6: If the fuse delay time ends during the grenade flight, replace t in the formula of step 5 with the fuse delay time t e Substitute in the numbers and calculate the position of the grenade in the air when it explodes; Step 7: When the absolute value of the grenade's total acceleration is greater than g, it means the grenade has landed. Record the landing time t d , replace t in the formula of step 5 with the landing time t d Substitute in and calculate the location of the grenade landing point, where g is the gravitational acceleration constant; Step 8: When the grenade fuse delay ends, the wireless communication unit transmits the explosion point location information calculated by the microprocessor.

3. The method according to claim 2, characterized in that Step 2 includes: when the grenade is thrown, without considering the air resistance, the grenade is only affected by gravity, and the total acceleration is about 0. Therefore, the microprocessor determines the time point t0 when the grenade is thrown according to the characteristic that the total acceleration is about 0, and calculates the velocity value V of the three axes at the time t0 when the grenade is thrown using the following formula: x 、V y 、V z : Use the following formula to calculate the initial velocity V0 of the grenade when it is thrown at time t0: The three-axis magnetic compass data when the grenade is thrown at time t0 is recorded as Using the three-axis magnetic compass data and the deviation value of the actual throwing direction, the actual throwing direction A0 of the grenade is obtained, and the air pressure value P0 of the air pressure sensor at the time t0 when the grenade is thrown is recorded; The moment the grenade is thrown, the simulated fuse is activated and the fuse timing begins.

4. The method according to claim 3, characterized in that In step 2, the three-axis magnetic compass data and the deviation value of the actual throwing direction are obtained by having the thrower repeatedly throw the grenade for multiple times and then measuring and counting.

5. The method according to claim 4, characterized in that In step 2, the coordinate position of the grenade when it is thrown is approximately replaced by the position information of the thrower when it is thrown.

6. The method according to claim 5, characterized in that Step 3 includes: recording the current air pressure sensor value as P t , the pressure sensor value collected at the previous moment is recorded as P t-ΔT , when P t <P t-ΔT , it is judged that the grenade is still in the rising stage; when P t >P t-ΔT , then the grenade is judged to be in the falling stage; record the first occurrence of P t >P t-ΔT Time t h0 , t h0 -ΔT is the time t when the grenade flies to the highest point h .

7. The method according to claim 6, characterized in that In step 4, the vertical component V of the grenade's velocity at the moment it is thrown is calculated using the following formula: v and the horizontal component V h , where g is the gravitational acceleration constant: V v =g·t h , 8. A storage medium, characterized in that: A computer program or instruction is stored, and when the computer program or instruction is executed, the method according to any one of claims 2 to 7 is implemented.

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