CN111650402B

CN111650402B - Trajectory vertex identification method based on triaxial accelerometer

Info

Publication number: CN111650402B
Application number: CN202010408912.8A
Authority: CN
Inventors: 张祥金; 杨雨悦
Original assignee: Nanjing University of Science and Technology
Current assignee: Nanjing University of Science and Technology
Priority date: 2020-05-14
Filing date: 2020-05-14
Publication date: 2022-04-12
Anticipated expiration: 2040-05-14
Also published as: CN111650402A

Abstract

The invention belongs to the field of fuze control, and particularly relates to a trajectory vertex identification method based on a triaxial accelerometer. The scheme comprises a projectile body and a fuse, wherein the fuse is fixedly arranged in the projectile body; the axis of the fuze is superposed with the axis of the projectile body; the fuse is fixedly provided with a PCB board, and the PCB board is provided with a power module, a triaxial accelerometer, a CPLD and a peripheral circuit. According to the scheme, two triaxial accelerometers arranged inside a detonator of a mortar shell are used for measuring xy plane and z axis acceleration values borne by the projectile in the ballistic flight process, and whether the projectile is in a launching state and reaches a ballistic vertex is judged through a threshold value + sequence + time window algorithm, so that an environment excitation signal is provided for remote fuse relief of the detonator. The invention adopts the accelerometer arranged in the fuse to judge the ballistic vertex signal, thereby controlling the state of the safety switch, and having the advantages of no damage to the pneumatic appearance of the projectile body, no need of an additional power-electricity conversion structure, easy engineering, high reliability and the like.

Description

Trajectory vertex identification method based on triaxial accelerometer

Technical Field

The invention belongs to the field of fuze control, and particularly relates to a trajectory vertex identification method based on a triaxial accelerometer.

Background

According to the requirements of GJB373A-97 and GJB6456-2008 on fuze design, the fuze electronic safety and fuse-release device needs two static switches and one dynamic switch as an initiation energy spacer, and environmental excitation signals for starting the fuse switches are independent from each other and are obtained from different environments. The electronic fuse safety and safety relief device is only applied to high-value weapon systems such as guided missiles, torpedoes and the like at present, and conventional ammunition such as mortar shells and the like is yet to be popularized.

Because the shot of the mortar is a micro-spinning shot, the fuze release environmental force of the mortar is generally the second environmental information such as aerodynamic force, electric insurance and the like except the recoil force in the current design, but the mortar has the defects of poor universality, poor fuze sealing property, short release distance and the like.

Disclosure of Invention

The invention aims to provide a trajectory vertex identification method based on a triaxial accelerometer, which is characterized in that two triaxial accelerometers arranged in a plane mortar shell fuse measure xy plane and z axis acceleration values borne by the projectile in a trajectory flight process, and whether the projectile is in a launching state and reaches a trajectory vertex is judged through a threshold value + sequence + time window algorithm, so that an environment excitation signal is provided for fuse arming.

The technical solution for realizing the purpose of the invention is as follows: a trajectory vertex identification method based on three-axis accelerometers is characterized in that two three-axis accelerometers arranged in a mortar shell fuse are used for measuring xy plane and z axis acceleration values borne by a projectile in a trajectory flight process, and whether the projectile is in a launching state and reaches a trajectory vertex is judged through a threshold value + sequence + time window algorithm.

Further, two triaxial accelerometer symmetric arrangement are in projectile body barycenter both sides, and triaxial accelerometer's three sensitive axle is respectively: the x axis points to the direction of the center of mass of the projectile, the y axis points to the advancing direction of the longitudinal axis of the projectile, and the z axis points to the tangential direction of the projectile.

Furthermore, the axis of the fuse is superposed with the axis of the projectile body, a PCB is fixedly arranged on the fuse, and the installation position of the PCB is vertical to the axis; and the PCB is provided with a power module, a CPLD, a triaxial accelerometer and a peripheral circuit.

Further, the specific steps of judging whether the projectile is in a launching state and reaches the ballistic vertex through the threshold + sequence + time window algorithm are as follows:

and setting a threshold A of the combined acceleration of the projectile on the xy plane of the projectile axis according to the measurement error of the triaxial accelerometer, setting a larger time window T according to the time range of the projectile to reach the vertex of the trajectory, sampling at the frequency f in the time window T, comparing with the threshold A, and releasing the safety switch if the logic of the CPLD module is met.

step (1): after the forced missile is launched, the CPLD acquires the accelerations of the x axis, the y axis and the z axis of the two triaxial accelerometers every 1ms in a time window T, and the accelerations are respectively marked as a_x1、a_x2、a_y1、a_y2、a_z1、a_z2And calculating the resultant acceleration a of the xy plane_xy；

Step (2): setting the maximum value a of the initial resultant acceleration_xymaxWhen the calculated total acceleration a is 0_xyIs compared with the maximum value if a_xyIf greater than the maximum value, update and overwrite a with the current value_xymax；

And (3): setting two addsInitial z-axis acceleration a of the speedometer_z0A is 0, collected_z1、a_z2Are respectively connected with a_z0By comparison, if a is in T/1ms times_z1、a_z2Are all less than a_z0If the shot is shot, the shot is shot and is off-line; if there is one of times a in T/1ms_z1、a_z2Is greater than or equal to a_z0If the shot is not in a normal launching state, the fuse can not release the safety switch state, and T is a preset time window;

and (4): real-time monitoring a_xymaxWhen a is sampled 3 times in succession_xymaxNot updated, compare it to a threshold A if a_xymaxIf the value is larger than or equal to the threshold value, the projectile reaches the ballistic vertex or just passes the ballistic vertex, and the CPLD sends out a corresponding safety release signal of the safety switch.

Compared with the prior art, the invention has the remarkable advantages that:

(1) the invention adopts the accelerometer arranged in the fuse to judge the ballistic vertex signal, thereby controlling the state of the safety switch, and having the advantages of no damage to the pneumatic appearance of the projectile body, no need of an additional power-electricity conversion structure, easy engineering, high reliability and the like; the application in electronic safety and safety release device can realize small-sized low-cost design.

(2) Because the launching environment of the projectile is not much in the available environment excitation signals, the invention provides the environment excitation signals by adopting a ballistic vertex signal identification mode, and provides a new scheme for the application of an electronic safety and safety relief device on the projectile.

(3) The distance generated by the solution signal exceeds half of the forced ejection stroke, so that remote safety relief control can be realized, and high safety of design is guaranteed.

(4) The invention adopts a double-accelerometer measurement mode to offset the error of the accelerometer system.

Drawings

Fig. 1 is a schematic view of the installation of the arming device of the full electronic safety system of the projectile fuse of the present invention.

Fig. 2 is a schematic structural diagram of a three-axis accelerometer in the arming device of the full electronic safety system of the projectile fuse of the present invention.

Description of reference numerals:

1-projectile-forcing projectile, 2-projectile-forcing fuze, 3-triaxial accelerometer I and 4-triaxial accelerometer II.

Detailed Description

The present invention is described in further detail below with reference to the attached drawing figures.

As shown in fig. 1-2, the invention comprises a projectile body and a projectile fuse 2, wherein the projectile fuse 2 is fixedly arranged in the projectile body, and the axis of the projectile fuse 2 is coincident with the axis of the projectile body; a PCB is fixedly arranged on the fuse, and the installation position of the PCB is vertical to the axis; the PCB is provided with a power module, a CPLD, a triaxial accelerometer and a peripheral circuit; two triaxial accelerometer symmetric arrangement are in projectile body barycenter both sides, and three sensitive axle is respectively: the x axis points to the direction of the center of mass of the projectile body, the y axis points to the advancing direction of the longitudinal axis of the projectile body, and the z axis points to the tangential direction of the projectile body; the fuse comprises a fuse shell and a hardware circuit; and the hardware circuit is embedded and fixed in the fuse shell.

The ballistic apex identification method of the present application is as follows:

two triaxial accelerometers are arranged in a mortar shell fuze to measure xy plane and z axis acceleration values borne by the projectile in a launching environment, and whether the projectile is in a launching state and reaches a trajectory vertex is judged through a threshold value + sequence + time window algorithm, so that environmental information excitation is provided for fuse relief.

Firstly, a threshold value A of the combined acceleration of the projectile on a projectile axis xy plane is set according to the measurement error of the accelerometer, a larger time window T is set according to the time range of the projectile to reach the top point of the trajectory, sampling is carried out in the time window at the frequency f and is compared with the threshold value A, and the safety switch is released if the logic of the CPLD module is met.

The specific implementation process is as follows:

(1) after the forced missile is launched, the CPLD acquires the accelerations of the x axis, the y axis and the z axis of the two triaxial accelerometers every 1ms in a time window T, and the accelerations are respectively marked as a_x1、a_x2、a_y1、a_y2、a_z1、a_z2And calculating the resultant acceleration a of the xy plane_xy；

(2) Setting the maximum value a of the initial resultant acceleration_xymaxWhen the calculated total acceleration a is 0_xyIs compared with the maximum value if a_xyIf greater than the maximum value, update and overwrite a with the current value_xymax，；

(3) Setting initial z-axis acceleration a of two accelerometers_z0A is 0, collected_z1、a_z2Are respectively connected with a_z0By comparison, if a is in T/1ms times_z1、a_z2Are all less than a_z0If the shot is shot, the shot is shot and is off-line; if there is one of times a in T/1ms_z1、a_z2Is greater than or equal to a_z0If the bullet is not in the normal launching state, the fuse can not release the state of the safety switch. T is a preset duration.

(4) Real-time monitoring a_xymaxWhen a is sampled 3 times in succession_xymaxNot updated, compare it to a threshold A if a_xymaxIf the value is larger than or equal to the threshold value, the projectile reaches the ballistic vertex or just passes the ballistic vertex, and the CPLD sends out a corresponding safety release signal of the safety switch.

The present invention is not limited to the embodiments, but various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A trajectory vertex identification method based on three-axis accelerometers is characterized in that two three-axis accelerometers arranged in a mortar shell fuse are used for measuring xy plane and z axis acceleration values borne by a projectile in a trajectory flight process, and whether the projectile is in a launching state and reaches a trajectory vertex is judged through a threshold value + sequence + time window algorithm;

two triaxial accelerometer symmetric arrangement are in projectile body barycenter both sides, and three sensitive axle of triaxial accelerometer is respectively: the x axis points to the direction of the center of mass of the projectile body, the y axis points to the advancing direction of the longitudinal axis of the projectile body, and the z axis points to the tangential direction of the projectile body;

the axis of the fuse is overlapped with the axis of the projectile body, a PCB is fixedly arranged on the fuse, and the installation position of the PCB is vertical to the axis; the PCB is provided with a power module, a CPLD, a triaxial accelerometer and a peripheral circuit;

the specific steps of judging whether the projectile is in a launching state and reaches a ballistic vertex through a threshold value + sequence + time window algorithm are as follows:

setting a threshold A of the combined acceleration of the projectile on a projectile axis xy plane according to the measurement error of the triaxial accelerometer, setting a larger time window T according to the time range of the projectile reaching the ballistic vertex, sampling at a frequency f in the time window T, comparing with the threshold A, and releasing the safety switch if the time meets the logic of a CPLD module;

step (1): after the mortar shell is launched, the CPLD acquires the accelerations of the x axis, the y axis and the z axis of two three-axis accelerometers every 1ms in a time window T, and the accelerations are respectively marked as a_x1、a_x2、a_y1、a_y2、a_z1、a_z2And calculating the resultant acceleration a of the xy plane_xy；

And (3): setting initial z-axis acceleration a of two accelerometers_z0A is 0, collected_z1、a_z2Are respectively connected with a_z0By comparison, if a is in T/1ms times_z1、a_z2Are all less than a_z0If the shot is shot, the shot is shot and is off-line; if there is one of times a in T/1ms_z1、a_z2Is greater than or equal to a_z0If the shot is not in a normal launching state, the fuse can not release the safety switch state, and T is a preset time window;