Intelligent grenade and security method thereof

Abstract

The application provides an intelligent hand grenade and a security method thereof. The security method comprises the following steps: setting a theftproof device of the intelligent hand grenade to start, collecting motion information of the intelligent hand grenade, calculating the motion information of the intelligent hand grenade, judging whether the motion state of the intelligent hand grenade is in a stolen state, and locking a fuse device of the intelligent hand grenade when the motion state of the intelligent hand grenade is in the stolen state. The security method can improve the transportation safety of the hand grenade and prevent the hand grenade from being lost and used for dangerous purposes.

Description

Technical Field

[0001] This invention belongs to the field of data analysis, specifically relating to an intelligent grenade and its security method. Background Technology

[0002] Hand grenades and other dangerous weapons possess massive destructive power, and their loss can cause enormous harm. The transportation and storage of hand grenades are subject to strict requirements, necessitating real-time and effective close tracking to prevent theft or misuse. Currently, there is a greater need for security technologies to prevent theft and misuse of hand grenades and other dangerous weapons. Although patent document CN107403531B provides a method, device, and readable storage medium for preventing theft of personal belongings, which can promptly issue an alarm when personal belongings are stolen or lost during daily use, it is still insufficient to prevent large-scale damage caused by dangerous weapons. Summary of the Invention

[0003] The purpose of this invention is to propose an intelligent grenade and its security method to solve one or more technical problems existing in the prior art, and at least provide a beneficial option or create conditions.

[0004] This invention provides a smart grenade and its security method. The anti-theft device installed on the smart grenade is activated, the movement information of the smart grenade is collected, the movement information of the smart grenade is calculated, and it is determined whether the movement state of the smart grenade is in a stolen state. If it is in a stolen state, the fuse device of the smart grenade is locked.

[0005] To achieve the above objectives, according to one aspect of the present invention, a smart grenade is provided, comprising an anti-theft device, a positioning device, a signal transmission device, a fuse device, a processor, and a memory, as well as a computer program stored in the memory and executable on the processor. The computer program controls whether the smart grenade detonates, and the processor executes the computer program in modules of the following system:

[0006] The motion recording module is used to activate the anti-theft device installed in the smart grenade;

[0007] A trajectory sensing module is used to collect the motion information of the smart grenade;

[0008] A motion calculation module is used to calculate the motion information of the smart grenade;

[0009] The motion detection module is used to determine whether the smart grenade is in a stolen state.

[0010] An anti-theft module is used to lock the fuse device of the smart grenade.

[0011] This invention also provides a security method for a smart grenade, wherein the security method for the smart grenade is applied to the smart grenade and includes the following steps:

[0012] S100, the anti-theft device installed on the smart grenade is activated;

[0013] S200, collect the motion information of the smart grenade;

[0014] S300, calculate the motion information of the smart grenade;

[0015] S400, determine whether the smart grenade is in a stolen state;

[0016] S500, when the device is stolen, the fuse of the smart grenade is locked.

[0017] The smart grenade further includes: a grenade body, the surface of which is provided with a pressure-activated switch, and the surface of the grenade body away from the pressure-activated switch being movably connected to an anti-theft device; a fixed half-ring is fixedly connected to the center of both the front and back of the anti-theft device, the inner wall of which is movably connected to the surface of the grenade body, and a clamping half-ring is fixedly connected to one end of the fixed half-ring on the back of the grenade body via a hinge; a mounting plate is fixedly connected to the surface of the fixed half-ring via a hinge, and the end of the mounting plate away from the fixed half-ring is movably connected to the surface of the clamping half-ring via a screw; a pressure-activated switch locking device is fixedly connected to the surface of the clamping half-ring, and the pressure-activated switch locking device is used to either lock (prevent detonation) the fuse of the smart grenade or to open the fuse of the smart grenade;

[0018] The pressure-activated switch locking device includes a solenoid valve and mounting screws. A circuit board is fixedly connected to the inner wall of the anti-theft device by screws. A UWB tag is provided on the surface of the circuit board. The UWB tag includes a vibration switch, a positioning chip, a clock circuit module, an accelerometer, a microcontroller, and a power supply housing. A lithium battery is provided inside the power supply housing. The vibration switch, positioning chip, clock circuit module, accelerometer, and lithium battery inside the power supply housing are all electrically connected to the microcontroller via wires. The microcontroller and lithium battery are electrically connected to the solenoid valve via wires. The solenoid valve receives signals from the microcontroller. The microcontroller can be used to execute steps S100 to S500 in the security method of the smart grenade. The solenoid valve is used to control the opening or locking of the pressure-activated switch.

[0019] The fuse device includes the pressure-activated switch, which controls whether the smart grenade detonates.

[0020] The positioning device includes the UWB tag;

[0021] The signal transmission device is used to transmit or receive data or to transmit signals from the UWB tag.

[0022] The anti-theft device includes the circuit board, a UWB tag on the surface of the circuit board, and the UWB tag includes a vibration switch, a positioning chip, a clock circuit module, an acceleration sensor, a microcontroller and a power supply housing, and a lithium battery inside the power supply housing; a UWB base station is set up at the location where the smart grenade is stored, and the UWB base station has a wireless transmission module inside for controlling, communicating, transmitting data or positioning the smart grenade.

[0023] Furthermore, in S100, the method for activating the anti-theft device installed on the smart grenade is as follows: the anti-theft device is connected to the signal transmission device, and the anti-theft device detects the activation signal obtained through the signal transmission device; when no activation signal is received, the anti-theft device is put into a sleep state, and the current coordinates of the smart grenade are recorded as the reference coordinates, that is, the coordinates of the smart grenade when the anti-theft device is activated are the reference coordinates; when the activation signal is received, the anti-theft device is controlled to activate and perform a self-test.

[0024] Furthermore, in S200, the method for collecting the motion information of the smart grenade is as follows:

[0025] Upon receiving the activation signal, the coordinates of the smart grenade are acquired at multiple consecutive different moments.

[0026] The coordinates of the smart grenade at each time point are obtained.

[0027] A Cartesian coordinate system is constructed with the reference coordinates as the origin. The Euclidean distance between the reference coordinates and the coordinates of the smart grenade at each time moment is calculated. The angle between the straight line formed by the reference coordinates and the coordinates of the smart grenade at each time moment is calculated on the Cartesian coordinate system. The two-dimensional array composed of the Euclidean distance and the angle at each time moment is used as each element, and the sequence composed of the order of each time moment is called the motion information of the smart grenade. Thus, the motion information is obtained.

[0028] Furthermore, in S300, the method for calculating the motion information of the smart grenade is as follows:

[0029] Obtain the motion information of the smart grenade.

[0030] Using a curve fitting algorithm, the coordinates of each different moment contained in the motion information of the smart grenade are fitted into a curve in time sequence as the motion trajectory of the grenade.

[0031] Let the trajectory of the grenade be curve Fline, and the number of elements in the motion information of the smart grenade be n. Random sampling is performed on curve Fline to obtain n different sampling points. The set of these n different sampling points is Fset. (Here, instead of using the original n coordinates at different times, n sampling points are randomly sampled from the fitted curve. The advantage of this is that the coordinates of the smart grenade at multiple different times are random in real-world scenarios. This randomness is a high-frequency event in the practical application of grenades. Sudden impacts caused by theft or other factors deviating from the original trajectory can lead to large deviations in the coordinates of the original trajectory at multiple times, which is extremely detrimental to statistically analyzing the trajectory of lost grenades and hinders their recovery.) The probability of a grenade is reduced, and the method further extracts the coordinates of the grenade at multiple different times, which can reduce the interference of random factors and effectively improve the fault tolerance in the accuracy calculation process. Each sampling point consists of the angle value between the coordinates of the smart grenade represented by the sampling point and the reference coordinates and the Euclidean distance value at a certain time. That is, a sampling point is an array composed of the angle value and the Euclidean distance value. The sequential number of each sampling point in Fline with the initial coordinate as the starting point is i, then i∈[1,n]. The sampling point with the number i is F(i). The sine value of the angle between the sampling point F(i) and the reference coordinates is g(i). The Euclidean distance value between the sampling point F(i) and the coordinates of the communication base station is e(i).

[0032] The motion state of the smart grenade can be calculated from this.

[0033] Furthermore, in S400, the method for determining whether the smart grenade is in a stolen state is as follows:

[0034] Based on calculations of the smart grenade's motion state, it is determined whether the grenade is in a stolen state, specifically as follows:

[0035] The boolean value `state` represents the movement state of the smart grenade. If `state` is True, it is in a normal state; if `state` is False, it is in a stolen state. Specifically:

[0036] S401, calculate the arithmetic mean of the Euclidean distances between each sampling point and the reference coordinates as e(avg);

[0037] S402, calculate the throw degree of each sampling point, and denote the throw degree of sampling point F(i) as por(i). The formula for calculating por(i) is:

[0038] ,

[0039] (The beneficial effects of calculating the throw angle are as follows: Given the randomness and suddenness of grenade displacement in actual scenarios, existing measurement techniques for calculating grenade positioning neglect the probabilistic influence and continuous relationship between coordinates at different times, making it difficult to estimate the continuous influence between coordinates. However, the throw angle described in this method, based on the calculation of sum(g,e), statistically analyzes the continuous probability of the included angle value and Euclidean distance value at different times. Then, by calculating the deviation of e(i) from the average level e(avg) and using g(i) for probability correction, it effectively reflects the probabilistic influence and continuous relationship between coordinates at different times, which is more conducive to the positioning and tracking of grenades in actual scenarios. It can be used for the safe tracking of grenades during transportation and the safe and stable storage of grenades.)

[0040] Where sum(g,e) represents the summation of the products of each g(i) and e(i) over i∈[1,n], and its calculation formula is:

[0041] ,

[0042] S403, obtain the mode or arithmetic mean of the Euclidean distance values ​​e(i) corresponding to each sampling point F(i) as e(mode), and determine whether e(mode) is greater than e(avg). If so, use e(mode) as the point selection threshold; otherwise, use e(avg) as the point selection threshold.

[0043] S404, calculate the absolute value of the difference between the Euclidean distance value e(i) corresponding to each sampling point F(i) and the selection threshold. Select the sampling point with the smallest absolute value of the difference with the selection threshold from each sampling point F(i) as the selected sampling point. Let the value of the index of the selected sampling point in [1,n] be i1, and the selected sampling point be F(i1). Get the throw degree corresponding to F(i1) as por(i1).

[0044] S405, obtain sampling point F(1) with sequence number 1, obtain sampling point F(n) with sequence number n, calculate the absolute value of the difference between the included angle value of F(1) and the included angle value of F(n) as the first and last angle difference, use the first and last angle difference as the angle and calculate the sine value of the angle as the sine value of the first and last angle difference; (using the first and last angle difference as the benchmark can effectively solve the problem of the grenade being passively rolled back due to the influence of external shock waves and blasting airflow during the movement. In this case, it is necessary to control the grenade to prevent it from exploding, otherwise it will pose a great danger to the transportation work;)

[0045] S406, determine whether the sine value of the difference between the first and last angles is less than 1 / 2 (i.e., the difference between the first and last angles is less than 30°, which can maximize the accuracy and safety of grenade transportation). If yes, go to S408; otherwise, go to S407.

[0046] S407, calculate the arithmetic mean of the throws of each sampling point in the set Fset except F(i1) as the throw mean, and determine whether the throw mean is less than the value of por(i1). If yes, go to S408; otherwise, go to S409.

[0047] S408, set state to False and output;

[0048] S409, set state to True and output;

[0049] A state of False indicates that the grenade is currently in a stolen state, while a state of True indicates that the grenade is in a normal state.

[0050] Furthermore, in S500, when the device is stolen, the method for locking the fuse of the smart grenade is as follows:

[0051] When the smart grenade receives a signal indicating that it is stolen, or when the smart grenade receives a signal indicating that it is stolen, the fuse device of the smart grenade is blocked, that is, the fuse device controls the smart grenade to prevent it from detonating, thereby preventing the fuse of the smart grenade from detonating.

[0052] The beneficial effects of this invention are as follows: This invention provides a smart grenade and its security method. The anti-theft device installed on the smart grenade is activated, the movement information of the smart grenade is collected, the movement information of the smart grenade is calculated, and it is determined whether the movement state of the smart grenade is in a stolen state. When it is in a stolen state, the fuse device of the smart grenade is blocked, thereby achieving the beneficial effects of improving the safety of grenade transportation and preventing the grenade from being lost and used for dangerous purposes. Attached Figure Description

[0053] The above and other features of the present invention will become more apparent from the detailed description of the embodiments shown in conjunction with the accompanying drawings. In the accompanying drawings, the same reference numerals denote the same or similar elements. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort. In the drawings:

[0054] Figure 1 The diagram shown is a flowchart of a security method for a smart grenade;

[0055] Figure 2The diagram shown is a system structure diagram of a smart grenade. Detailed Implementation

[0056] The following will provide a clear and complete description of the concept, specific structure, and technical effects of the present invention in conjunction with the embodiments and accompanying drawings, so as to fully understand the purpose, solution, and effects of the present invention. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0057] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0058] like Figure 1 The diagram shown is a flowchart of a security method for a smart grenade according to the present invention. Figure 2 The diagram shown is a system structure diagram of a smart grenade according to the present invention. The following is a description of the system structure of the grenade. Figure 1 and Figure 2 This paper describes a smart grenade and its security method according to an embodiment of the present invention.

[0059] The security method for a smart grenade is applied to the smart grenade, such as... Figure 1 As shown, the security method for a smart grenade includes the following steps:

[0060] S100, the anti-theft device installed on the smart grenade is activated;

[0061] S200, collect the motion information of the smart grenade;

[0062] S300, calculate the motion information of the smart grenade;

[0063] S400, determine whether the smart grenade is in a stolen state;

[0064] S500, when the device is stolen, the fuse of the smart grenade is locked.

[0065] The smart grenade includes an anti-theft device, a positioning device, a signal transmission device, a fuse device, a processor, a memory, and a computer program stored in the memory and executable on the processor. The computer program controls whether the smart grenade detonates. Figure 2As shown, the processor executes the computer program in the following system modules. Preferably, the smart grenade may include the structure of a passive UWB grenade safety protection device as described in patent document CN213631825U, wherein each module implements the steps in the security method of the smart grenade:

[0066] The motion recording module is used to activate the anti-theft device installed in the smart grenade;

[0067] A trajectory sensing module is used to collect the motion information of the smart grenade;

[0068] A motion calculation module is used to calculate the motion information of the smart grenade;

[0069] The motion detection module is used to determine whether the smart grenade is in a stolen state.

[0070] An anti-theft module is used to lock the fuse device of the smart grenade.

[0071] The smart grenade may further include: a grenade body, the surface of which is provided with a pressure-activated switch, and the surface of the grenade body away from the pressure-activated switch being movably connected to an anti-theft device; a fixed half-ring is fixedly connected to the center of both the front and back of the anti-theft device, the inner wall of which is movably connected to the surface of the grenade body, a clamping half-ring is fixedly connected to one end of the fixed half-ring on the back of the grenade body via a hinge, a mounting plate is fixedly connected to the surface of the fixed half-ring via a hinge, the end of the mounting plate away from the fixed half-ring is movably connected to the surface of the clamping half-ring via a screw, and a pressure-activated switch locking device is fixedly connected to the surface of the clamping half-ring, the pressure-activated switch locking device being used to lock the fuse of the smart grenade and to open the fuse of the smart grenade;

[0072] The pressure-activated switch locking device includes a solenoid valve and mounting screws. A circuit board is fixedly connected to the inner wall of the anti-theft device by screws. A UWB tag is provided on the surface of the circuit board. The UWB tag includes a vibration switch, a positioning chip, a clock circuit module, an accelerometer, a microcontroller, and a power supply housing. A lithium battery is provided inside the power supply housing. The vibration switch, positioning chip, clock circuit module, accelerometer, and lithium battery inside the power supply housing are all electrically connected to the microcontroller via wires. The microcontroller and lithium battery are electrically connected to the solenoid valve via wires. The solenoid valve receives signals from the microcontroller. The microcontroller can be used to execute steps S100 to S500 in the security method of the smart grenade. The solenoid valve is used to control the opening or locking of the pressure-activated switch.

[0073] The fuse device includes the pressure-activated switch, which controls whether the smart grenade detonates.

[0074] The positioning device includes the UWB tag;

[0075] The signal transmission device is used to transmit or receive data or to transmit signals from the UWB tag.

[0076] The anti-theft device includes the circuit board, a UWB tag on the surface of the circuit board, and the UWB tag includes a vibration switch, a positioning chip, a clock circuit module, an acceleration sensor, a microcontroller and a power supply housing, and a lithium battery inside the power supply housing; a UWB base station is set up at the location where the smart grenade is stored, and the UWB base station has a wireless transmission module inside for controlling, communicating, transmitting data or positioning the smart grenade.

[0077] Preferably, the smart grenade can be an improvement on a passive UWB grenade safety protection device based on the publication number CN213631825U, and the anti-theft device can correspond to the control shell of the passive UWB grenade safety protection device described in the publication number CN213631825U.

[0078] Furthermore, in S100, the method for activating the anti-theft device installed on the smart grenade is as follows: the anti-theft device is connected to the signal transmission device, and the anti-theft device detects the activation signal obtained through the signal transmission device; when no activation signal is received, the anti-theft device is put into a sleep state, and the current coordinates of the smart grenade are recorded as the reference coordinates; when the activation signal is received, the anti-theft device is activated and performs a self-test.

[0079] Furthermore, in S200, the method for collecting the motion information of the smart grenade is as follows:

[0080] Upon receiving the activation signal, the coordinates of the smart grenade are acquired at multiple consecutive different moments.

[0081] At each moment, the coordinates of the smart grenade are obtained. A Cartesian coordinate system is constructed with the reference coordinates as the origin. The Euclidean distance between the reference coordinates and the coordinates of the smart grenade at each moment is calculated. The angle between the straight line formed by the reference coordinates and the coordinates of the smart grenade at each moment is also calculated on the Cartesian coordinate system. The two-dimensional array composed of the Euclidean distance and the angle at each moment is used as each element, and the sequence composed of the order of each moment is called the motion information of the smart grenade. Thus, the motion information is obtained.

[0082] Furthermore, in S300, the method for calculating the motion information of the smart grenade is as follows:

[0083] The motion information of the smart grenade is obtained, and a curve fitting algorithm is used to fit the coordinates of the smart grenade at different times in time sequence as the motion trajectory of the grenade.

[0084] Let the trajectory of the grenade be curve Fline, and let the number of elements in the motion information of the smart grenade be n. Randomly sample n different sampling points from curve Fline, and the set of the n different sampling points is Fset. Each sampling point consists of the angle between the coordinates of the smart grenade at a certain moment and the reference coordinates and the Euclidean distance. That is, a sampling point is an array composed of the angle and the Euclidean distance. The sequential number of each sampling point in Fline with the initial coordinate as the starting point is i, then i∈[1,n]. The sampling point with the number i is F(i). Let the sine of the angle between sampling point F(i) and the reference coordinates be g(i), and let the Euclidean distance between sampling point F(i) and the coordinates of the communication base station be e(i).

[0085] The motion state of the smart grenade can be calculated from this.

[0086] Furthermore, in S400, the method for determining whether the smart grenade is in a stolen state is as follows:

[0087] Based on calculations of the smart grenade's motion state, it is determined whether the grenade is in a stolen state, specifically as follows:

[0088] The boolean value `state` represents the movement state of the smart grenade. If `state` is True, it is in a normal state; if `state` is False, it is in a stolen state. Specifically:

[0089] S401, calculate the arithmetic mean of the Euclidean distances between each sampling point and the reference coordinates as e(avg);

[0090] S402, calculate the throw degree of each sampling point, and denote the throw degree of sampling point F(i) as por(i). The formula for calculating por(i) is:

[0091] ,

[0092] Where sum(g,e) represents the summation of the products of each g(i) and e(i) over i∈[1,n], and its calculation formula is:

[0093] ,

[0094] S403, obtain the mode or arithmetic mean of the Euclidean distance values ​​e(i) corresponding to each sampling point F(i) as e(mode), and determine whether e(mode) is greater than e(avg). If so, use e(mode) as the point selection threshold; otherwise, use e(avg) as the point selection threshold.

[0095] S404, calculate the absolute value of the difference between the Euclidean distance value e(i) corresponding to each sampling point F(i) and the selection threshold. Select the sampling point with the smallest absolute value of the difference with the selection threshold from each sampling point F(i) as the selected sampling point. Let the value of the index of the selected sampling point in [1,n] be i1, and the selected sampling point be F(i1). Get the throw degree corresponding to F(i1) as por(i1).

[0096] S405, obtain the sampling point with the sequence number 1 as F(1), obtain the sampling point with the sequence number n as F(n), calculate the absolute value of the difference between the included angle value of F(1) and the included angle value of F(n) as the first and last angle difference, use the first and last angle difference as the angle and calculate the sine value of the angle as the sine value of the first and last angle difference.

[0097] S406, determine whether the sine value of the difference between the first and last angles is less than 1 / 2. If yes, go to S408; otherwise, go to S407.

[0098] S407, calculate the arithmetic mean of the throws of each sampling point in the set Fset except F(i1) as the throw mean, and determine whether the throw mean is less than the value of por(i1). If yes, go to S408; otherwise, go to S409.

[0099] S408, set state to False and output;

[0100] S409, set state to True and output;

[0101] A state of False indicates that the grenade is currently in a stolen state, while a state of True indicates that the grenade is in a normal state.

[0102] Furthermore, in S500, when the device is stolen, the method for locking the fuse of the smart grenade is as follows:

[0103] When the smart grenade receives a signal indicating that it is stolen, or when the smart grenade receives a signal indicating that it is stolen, the fuse device of the smart grenade is blocked, thereby preventing the fuse of the smart grenade from detonating.

[0104] Preferably, all undefined variables in this invention, if not explicitly defined, can be manually set thresholds.

[0105] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete component gate circuits, transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor. This processor is the control center of the smart grenade, connecting various sub-areas of the smart grenade via various interfaces and lines.

[0106] The memory can be used to store the computer program and / or modules. The processor implements various functions of the smart grenade and its security method by running or executing the computer program and / or modules stored in the memory and calling the data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the mobile phone (such as audio data, phonebook, etc.). In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0107] This invention provides a smart grenade and its security method. The anti-theft device installed on the smart grenade is activated to collect the movement information of the smart grenade. The movement information of the smart grenade is calculated to determine whether the movement state of the smart grenade is in a stolen state. If it is in a stolen state, the fuse device of the smart grenade is locked. This invention achieves the beneficial effects of improving the security of grenade transportation and preventing the grenade from being lost and used for dangerous purposes.

[0108] Although the invention has been described in considerable detail and particularly with regard to several of the described embodiments, it is not intended to limit itself to any of these details or embodiments or any particular embodiment, thereby effectively covering the intended scope of the invention. Furthermore, the invention has been described above with respect to embodiments foreseeable by the inventors in order to provide a useful description, and non-substantial modifications to the invention that have not yet been foreseen may still represent equivalent modifications.

Claims

1. A security method for a smart grenade, comprising the following steps: S100, the anti-theft device installed on the smart grenade is activated; S200, collect the motion information of the smart grenade; S300, calculate the motion information of the smart grenade; S400, determine whether the smart grenade is in a stolen state; S500, when the device is stolen, the fuse of the smart grenade is locked; In S100, the method for activating the anti-theft device set on the smart grenade is as follows: when no activation signal is received, the anti-theft device is put into a dormant state, and the current coordinates of the smart grenade are recorded as the reference coordinates; when an activation signal is received, the anti-theft device is activated and a self-test is performed. In S200, the method for collecting the motion information of the smart grenade is as follows: Upon receiving the activation signal, the coordinates of the smart grenade are acquired at multiple consecutive different moments. At each moment, the coordinates of the smart grenade are obtained. A Cartesian coordinate system is constructed with the reference coordinates as the origin. The Euclidean distance between the reference coordinates and the coordinates of the smart grenade at each moment is calculated. The angle between the straight line formed by the reference coordinates and the coordinates of the smart grenade at each moment is calculated on the Cartesian coordinate system. The two-dimensional array composed of the Euclidean distance and the angle at each moment is used as each element. The sequence composed of the Euclidean distance and the angle at each moment is called the motion information of the smart grenade. Thus, the motion information is obtained. In S300, the method for calculating the motion information of the smart grenade is as follows: The motion information of the smart grenade is obtained, and a curve fitting algorithm is used to fit the coordinates of the smart grenade at different times in time sequence as the motion trajectory of the grenade. Let the trajectory of the grenade be curve Fline, and let the number of elements in the motion information of the smart grenade be n. Randomly sample n different sampling points from curve Fline, and the set of the n different sampling points is Fset. Each sampling point consists of the angle between the coordinates of the smart grenade at a certain moment and the reference coordinates and the Euclidean distance. That is, a sampling point is an array composed of the angle and the Euclidean distance. The sequential number of each sampling point in Fline with the initial coordinate as the starting point is i, then i∈[1,n]. The sampling point with the number i is F(i). Let the sine of the angle between sampling point F(i) and the reference coordinates be g(i), and let the Euclidean distance between sampling point F(i) and the coordinates of the communication base station be e(i). The motion state of the smart grenade is thus calculated. Furthermore, in S400, the method for determining whether the smart grenade is in a stolen state is as follows: Based on calculations of the smart grenade's motion state, it is determined whether the grenade is in a stolen state, specifically as follows: The boolean value `state` represents the movement state of the smart grenade. If `state` is True, it is in a normal state; if `state` is False, it is in a stolen state. Specifically: S401, calculate the arithmetic mean of the Euclidean distances between each sampling point and the reference coordinates as e(avg); S402, calculate the throw degree of each sampling point, and denote the throw degree of sampling point F(i) as por(i). The formula for calculating por(i) is: ； Where sum(g,e) represents the summation of the products of each g(i) and e(i) over i∈[1,n], and its calculation formula is: ； S403, obtain the mode or arithmetic mean of the Euclidean distance values ​​e(i) corresponding to each sampling point F(i) as e(mode), and determine whether e(mode) is greater than e(avg). If so, use e(mode) as the point selection threshold; otherwise, use e(avg) as the point selection threshold. S404, calculate the absolute value of the difference between the Euclidean distance value e(i) corresponding to each sampling point F(i) and the selection threshold. Select the sampling point with the smallest absolute value of the difference with the selection threshold from each sampling point F(i) as the selected sampling point. Let the value of the index of the selected sampling point in [1,n] be i1, and the selected sampling point be F(i1). Get the throw degree corresponding to F(i1) as por(i1). S405, obtain the sampling point with the sequence number 1 as F(1), obtain the sampling point with the sequence number n as F(n), calculate the absolute value of the difference between the included angle value of F(1) and the included angle value of F(n) as the first and last angle difference, use the first and last angle difference as the angle and calculate the sine value of the angle as the sine value of the first and last angle difference. S406, determine whether the sine value of the difference between the first and last angles is less than 1 / 2. If yes, go to S408; otherwise, go to S407. S407, calculate the arithmetic mean of the throws of each sampling point in the set Fset except F(i1) as the throw mean, and determine whether the throw mean is less than the value of por(i1). If yes, go to S408; otherwise, go to S409. S408, set state to False and output; S409 sets state to True and outputs it.

2. The security method for a smart grenade according to claim 1, characterized in that, In S500, when the device is stolen, the method for locking the fuse of the smart grenade is as follows: When the smart grenade receives a signal indicating that it is stolen, or when the smart grenade receives a signal indicating that it is stolen, the fuse device of the smart grenade is blocked, thereby preventing the fuse of the smart grenade from detonating.

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