High-reliability initiation control circuit based on fuze

Abstract

The application discloses a high-reliability ignition control circuit based on a fuse, comprising an energy storage unit, a charging unit, a firing control unit, a short-circuit protection unit and a microcontroller; the energy storage unit is connected with a working power input end at an input side and connected with the charging unit and the microcontroller at an output side; the microcontroller is connected with the firing control unit and the short-circuit protection unit at an output side; the charging unit is connected with a firing voltage input end of the firing control unit at an output side; and the firing control unit is connected with a firing voltage input end of the short-circuit protection unit at an output side. The application can effectively prevent common cause failure problems, improve the working reliability of the ignition circuit in power-on and power-off and in a severe electromagnetic environment, effectively solve the early explosion problem of the fuse possibly generated in a test process, and has the advantages of small size, high applicability and reliability and the like due to the all-electronic design and simple circuit.

Description

Technical Field

[0001] This invention belongs to the technical field of fuze detonation control circuits, specifically relating to a high-reliability detonation control circuit based on a fuze. Background Technology

[0002] The detonation control circuit of the fuze is responsible for issuing the final detonation command, and its reliability is an important consideration for engineers. When the fuze is tested with the warhead or during flight testing, under the influence of impact acceleration and various physical fields (including lightning, nuclear electromagnetic pulse, electrostatic discharge, and triboelectricity), the detonation control circuit will be interfered with through conduction or electromagnetic radiation. The control strategy of the detonation control circuit will fail, which will easily cause the fuze to detonate prematurely. To prevent this failure, the design of the detonation control circuit needs to be optimized to improve the reliability of the detonation control strategy. Traditional detonation control circuits typically use a single electronic device switch to control the ignition voltage of the pyrotechnic device. While the circuit is simple, it has poor anti-interference performance. Transient interference signals can be directly injected into the ignition circuit through current or coupled into the ignition circuit through rapidly changing electromagnetic fields. In recent years, some engineers have improved the design of detonation control circuits by implementing electronic short-circuit protection for the pyrotechnic device. This method has suppressed transient signal interference to some extent, but it does not effectively control the ignition voltage. If the short-circuit protection design fails, there is still a risk of accidental detonation of the pyrotechnic device. Some detonation control circuits use multiple points to control the ignition voltage, but this method does not provide short-circuit protection for the pyrotechnic device, and the detonation control circuit has a single control strategy, making it prone to common-cause failures. Summary of the Invention

[0003] This invention provides a highly reliable detonation control circuit based on a fuze. It uses a dual-point series connection mode of a current-controlled thyristor and a voltage-controlled field-effect transistor to control the ignition voltage of the charging capacitor. At the same time, the field-effect transistor controls the electric pyrotechnic device to be in a short-circuit protection state when it is not in the detonation working state through microcontroller commands and RC filter circuits, eliminating the risk of premature detonation caused by instantaneous failure of the control circuit. The ignition command control terminal adopts an anti-common cause failure and error prevention design, which greatly improves the reliability of the fuze.

[0004] To achieve the above objectives, the present invention employs the following technical solution:

[0005] A high-reliability detonation control circuit based on a fuze includes an energy storage unit, a charging unit, an ignition control unit, a short-circuit protection unit, and a microcontroller. The energy storage unit is connected to the working power input terminal on its input side and to the charging unit and the microcontroller on its output side. The microcontroller is connected to the ignition control unit and the short-circuit protection unit on its output side. The charging unit is connected to the ignition voltage input terminal of the ignition control unit on its output side and to the ignition voltage input terminal of the short-circuit protection unit on its output side.

[0006] As a preferred embodiment of the above scheme, the microcontroller is a 32-bit microcontroller based on the M23 core, and the microcontroller is equipped with control I / O ports P1.1, P1.2, P2.2 and sampling port P2.1.

[0007] As a preferred embodiment of the above scheme, the short-circuit protection unit includes sampling resistors R7 and R8, a field-effect transistor V4, a pull-up resistor R9, a pull-down resistor R10, and a RC filter network R12 and C4. One end of the sampling resistors R7 and R8 is connected in series to GND, and the other end is connected to the sampling I / O port P2.1 of the microcontroller. The other end of the sampling resistor R8 is connected to the ignition voltage input of the ignition control unit. The RC filter network R12 and C4 and the pull-down resistor R10 are connected in series. The input side of the series connection is connected to the control I / O port P2.2 of the microcontroller, and the output side is connected to the gate of the field-effect transistor V4 and GND. The gate of the field-effect transistor V4 is also connected to one end of the pull-up resistor R9. The drain and source of the field-effect transistor V4 are connected to the two ends of the electro-explosive device for parallel short-circuit protection.

[0008] As a preferred embodiment of the above scheme, the ignition control unit includes a thyristor V2, an RC filter network C2 and R4, a current-limiting resistor R3, a PNP transistor V3, a protection resistor R5, a pull-down resistor R6, and a bypass capacitor C3. The protection resistor R5, the pull-down resistor R6, and the bypass capacitor C3 are connected in series. The input side of the series connection is connected to the control I / O ports P1.1 and P1.2 of the microcontroller. The output side is connected to the base and emitter of the PNP transistor V3, respectively. The collector of the PNP transistor V3 is connected in parallel with the current-limiting resistor R3, the RC filter network C2, and R4 and then connected to the control electrode of the thyristor V2. The anode of the thyristor V3 is connected to the ignition output voltage of the ignition control unit, and the cathode of the thyristor V3 is connected to the ignition voltage input terminal of the short-circuit protection unit.

[0009] As a preferred embodiment of the above scheme, the charging unit includes a current-limiting resistor R1, a switching diode V1, a charging capacitor C1, and a bleeder resistor R2 connected in series. The input side of the series connection is connected to the charging power input terminal VCC2 and the output ground of the linear regulator U1, and the output side is connected to the ignition voltage input terminal of the ignition control unit. Only when the microcontroller P1.1 outputs a low level, P1.2 outputs a high level, and P2.2 outputs a low level can the ignition voltage of the charging capacitor C1 be applied to the electric pyrotechnic device.

[0010] As a preferred embodiment of the above scheme, the energy storage unit includes Schottky diodes V5, V6, and V7, a current-limiting resistor R11, energy storage capacitors C5 and C6, and a linear regulator U1. The Schottky diodes V5, V6, and V7 are connected in parallel, with their input sides connected to the working power supply input terminal VCC1 and their output sides connected to the input terminal of the linear regulator U1. The current-limiting resistor R11 is connected in series on the input sides of V6 and V7. The energy storage capacitor C5 is connected to the common terminal of Schottky diode V6 and the power supply ground, and the energy storage capacitor C6 is connected to the common terminal of Schottky diode V7 and the power supply ground. The power supply ground is connected to the input terminal of the linear regulator U1.

[0011] As a preferred embodiment of the above scheme, Schottky diode V5 is a single-tube Schottky diode, and Schottky diodes V6 and V7 are dual-tube Schottky diodes.

[0012] As a preferred embodiment of the above scheme, the power input terminal of the energy storage unit is connected to one end of the pull-up resistor R9 of the short-circuit protection unit after passing through Schottky diodes V5, V6, and V7 to provide a pull-up voltage.

[0013] Due to the above structure, the beneficial effects of the present invention are as follows:

[0014] 1. The ignition control unit of the detonation control circuit adopts a current-type control device thyristor, and the short-circuit protection unit adopts a voltage-type control device field-effect transistor. Different control types of semiconductor tubes are used in the design. At the same time, the microcontroller has an error-proof design for the control commands of the ignition control unit, which effectively prevents common cause failure and improves the reliability of the detonation circuit in power-on and power-off and in harsh electromagnetic environments.

[0015] 2. The short-circuit protection unit of the detonation control circuit connects the field-effect transistor and the electro-explosive transistor in parallel. In a safe state, the electro-explosive is protected against short circuit by an electronic switch. At the same time, the control gate of the field-effect transistor is pulled up. If a single point failure of the microcontroller occurs during the dynamic test, the field-effect transistor will remain in the conducting state, and the electro-explosive will be short-circuited, effectively solving the problem of premature detonation of the fuse that may occur during the test.

[0016] 3. The detonation control circuit adopts a fully electronic design, which has the advantages of simple circuit, small size, applicability and high reliability. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0018] Figure 1 This is the circuit schematic diagram of the present invention. Detailed Implementation

[0019] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0020] like Figure 1 As shown, this embodiment provides a high-reliability detonation control circuit based on a fuze, including an energy storage unit 1, a charging unit 2, an ignition control unit 3, a short-circuit protection unit 4, and a microcontroller 5. The input side of the energy storage unit 1 is connected to the working power input terminal, and the output side is connected to the charging unit 2 and the microcontroller 5. The output side of the microcontroller 5 is connected to the ignition control unit 3 and the short-circuit protection unit 4. The output side of the charging unit 2 is connected to the ignition voltage input terminal of the ignition control unit 3, and the output side of the ignition control unit 3 is connected to the ignition voltage input terminal of the short-circuit protection unit 4.

[0021] in:

[0022] The microcontroller 5 is a 32-bit microcontroller based on the M23 core. The microcontroller 5 is equipped with control I / O ports P1.1, P1.2, P2.2 and sampling port P2.1. The control I / O ports P1.1 and P1.2 of the microcontroller 5 are of the same type.

[0023] The short-circuit protection unit 4 includes sampling resistors R7 and R8, a field-effect transistor V4, a pull-up resistor R9, a pull-down resistor R10, and a RC filter network R12 and C4. One end of the sampling resistors R7 and R8 is connected in series to GND, and the other end is connected to the sampling IO port P2.1 of the microcontroller 5. The other end of the sampling resistor R8 is connected to the ignition voltage input of the ignition control unit 3. The analog voltage is collected in real time after being divided by the sampling resistors R7 and R8 to monitor the ignition voltage value output by the ignition control unit 3. The RC filter network R12 and C4, along with the pull-down resistor R10, are connected in series. The input side is connected to the control I / O port P2.2 of the microcontroller 5, and the output side is connected to the gate and GND of the field-effect transistor V4. When control port P2.2 outputs a high level, exceeding the threshold voltage of V4 (1.2V), V4 is in the on-state. Its on-resistance is in the mΩ range, while the internal resistance of the pyrotechnic device is in the Ω range. Therefore, the discharge circuit passes through the field-effect transistor. When a detonation signal is required, P2.2 outputs a low level, V4 is cut off, and the discharge circuit passes through the pyrotechnic device with lower resistance, causing it to ignite. The gate of V4 is also connected to one end of the pull-up resistor R9, and the drain and source of V4 are connected in parallel across the pyrotechnic device for short-circuit protection. The pull-up voltage on pull-up resistor R9 ensures that MOSFET V4 remains on during testing and in the event of a single-point failure at the microcontroller 5 control terminal, preventing the short circuit of the electrical components. Furthermore, the presence of pull-down resistor R10, RC filter network R12, and C4 between the gate and source of MOSFET V4 helps to mitigate the Miller effect in MOSFET V4 gate control, improving its reliability. R12 is in the hundreds of ohms range, R8, R9, and R10 are in the tens of kΩ range, and R7 is 1 kΩ.

[0024] The ignition control unit 3 includes a thyristor V2, an RC filter network C2 and R4, a current-limiting resistor R3, a PNP transistor V3, a protection resistor R5, a pull-down resistor R6, and a bypass capacitor C3. The protection resistor R5, pull-down resistor R6, and bypass capacitor C3 are connected in series. The input side of this series connection is connected to the control I / O ports P1.1 and P1.2 of the microcontroller 5. The output side is connected to the base and emitter of the PNP transistor V3, respectively. The collector of the PNP transistor V3 is connected in parallel with the current-limiting resistor R3, the RC filter network C2, and R4, and then connected to the control electrode of the thyristor V2. The anode of the thyristor V3 is connected to the ignition output voltage of the ignition control unit 3, and the cathode of the thyristor V3 is connected to the ignition voltage input terminal of the short-circuit protection unit 4. The current-limiting resistors R3, R4, R5, and R6 are in the kΩ range, and C2 and C3 are in the μF range. The trigger current of the control electrode of the thyristor V3 is no greater than 200μA, and the trigger voltage is no greater than 0.8V.

[0025] When the microcontroller's control ports P1.1 and P1.2 are configured to be low and high respectively, the PNP transistor V3 is effectively turned on. Any other instruction combination will not turn on the PNP transistor V3, effectively suppressing common-mode interference. The RC filter network C2 and R4 effectively suppress transient interference signals at the control terminal of thyristor V2.

[0026] The thyristor V2 of the ignition control unit 3 is a current-controlled device, and the field-effect transistor V4 of the short-circuit protection unit 4 is a voltage-controlled device. By using two different control methods, namely current and voltage, the ignition voltage discharge of the charging capacitor is controlled in a two-point series mode, which further suppresses the common cause interference failure problem and improves the reliability of the discharge of the charging capacitor C1.

[0027] The charging unit 2 includes a current-limiting resistor R1, a switching diode V1, a charging capacitor C1, and a bleeder resistor R2 connected in series. The input side of the series connection is connected to the charging power input terminal VCC2 and the output ground of the linear regulator U1. The output side is connected to the ignition voltage input terminal of the ignition control unit 3. The bleeder resistor R2 has a resistance of MΩ or higher, capable of discharging the voltage on the charging capacitor C1 during testing and detonation. The ignition voltage of the charging capacitor C1 can only be applied to the pyrotechnic device when P1.1 of the microcontroller 5 is low, P1.2 is high, and P2.2 is low. The charging time constant is 4*R1*C1, where R1 is in the hundreds of Ω range, C1 is in the μF range, and the charging time is completed within milliseconds.

[0028] The energy storage unit 1 includes Schottky diodes V5, V6, and V7, a current-limiting resistor R11, energy storage capacitors C5 and C6, and a linear regulator U1. The Schottky diodes V5, V6, and V7 are connected in parallel, with their input side connected to the working power supply input terminal VCC1 and their output side connected to the input terminal of the linear regulator U1. Among them, Schottky diode V5 is a single-transistor Schottky diode, and Schottky diodes V6 and V7 are dual-transistor Schottky diodes. The current-limiting resistor R11 is connected in series on the input side of V6 and V7. The energy storage capacitor C5 is connected to the common terminal of Schottky diode V6 and the power supply ground, and the energy storage capacitor C6 is connected to the common terminal of Schottky diode V7 and the power supply ground. The power supply ground is connected to the input terminal of the linear regulator U1. The linear regulator U1 can convert the input voltage VCC1 into a stable output VCC3 to power the microcontroller 5. The energy storage time of the energy storage unit 1 is 4*R11*(C5+C6), the resistance of R11 is in the hundreds of Ω range, and the capacitance of C5 and C6 is in the hundreds of μF range.

[0029] The power input terminal of energy storage unit 1 is connected to one end of pull-up resistor R9 of short-circuit protection unit 4 via Schottky diodes V5, V6, and V7, providing a pull-up voltage. This pull-up voltage, after being divided by pull-up resistor R9 and pull-down resistor R10, results in a gate voltage of MOSFET V4 that is greater than the MOSFET's turn-on voltage. In non-detonation states, this pull-up voltage ensures that MOSFET V4 of short-circuit protection unit 4 remains on, preventing accidental activation of the pyrotechnic device. Energy storage unit 1 ensures that the detonation control circuit continues to operate even when external power is lost during dynamic processes. The energy storage time is determined by the resistance value of current-limiting resistor R11 and the capacitance values ​​of energy storage capacitors C5 and C6. R11 has a resistance value in the hundreds of ohms range, and C5 and C6 have capacitance values ​​in the hundreds of μF range.

[0030] The working principle of the above structure:

[0031] When the fuse needs to output an initiation signal, and the input voltage VCC1 is at the power supply voltage input terminal, the energy storage unit 1 converts VCC1 to a stable VCC3 through the linear regulator U1 to power the microcontroller 5; on the other hand, it charges through the energy storage capacitors C5 and C6 to ensure that the initiation control circuit works for a certain period of time after losing energy during the dynamic test. When the charging power supply VCC2 is input, the charging capacitor C1 is charged through R1. When the fuse is ready to detonate, the microcontroller 5 outputs a low level on P1.1 and a high level on P1.2. The voltage between the base and emitter of the PNP transistor V3 is 0.7V higher than the cutoff voltage of the transistor V3, so the emitter junction is turned on and current flows between the base and collector. As a result, the thyristor V2 is turned on due to the control electrode trigger current. The ignition voltage of the charging capacitor enters the short-circuit protection unit 4 through the thyristor V2. At this time, the microcontroller 5 collects the analog voltage divided by the sampling resistor R7 and calculates the ignition voltage value. At the same time, the control port P2.2 outputs a low level, and the field-effect transistor V4 is turned off and does not conduct. Therefore, the discharge circuit ignites the electric pyrotechnic device with a small internal resistance.

[0032] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high reliability initiation control circuit based on a fuze, characterized in that: It includes an energy storage unit (1), a charging unit (2), an ignition control unit (3), a short-circuit protection unit (4), and a microcontroller (5). The energy storage unit (1) is connected to the working power input terminal on the input side and to the charging unit (2) and microcontroller (5) on the output side. The microcontroller (5) is connected to the ignition control unit (3) and short circuit protection unit (4) on the output side. The charging unit (2) is connected to the ignition voltage input terminal of the ignition control unit (3) on the output side. The ignition control unit (3) is connected to the ignition voltage input terminal of the short circuit protection unit (4) on the output side. The short-circuit protection unit (4) includes sampling resistors R7 and R8, field-effect transistor V4, pull-up resistor R9, pull-down resistor R10, and RC filter network R12 and C4; The sampling resistors R7 and R8 are connected in series. One end is connected to GND, and the other end is connected to the sampling IO port P2.1 of the microcontroller (5). The other end of the sampling resistor R8 is connected to the ignition voltage input of the ignition control unit (3). The RC filter network R12 and C4 and the pull-down resistor R10 are connected in series. After being connected in series, the input side is connected to the control IO port P2.2 of the microcontroller (5), and the output side is connected to the gate of the field effect transistor V4 and GND. The gate of the field effect transistor V4 is also connected to one end of the pull-up resistor R9. The drain and source of the field effect transistor V4 are connected to the two ends of the electric pyrotechnic device for parallel short-circuit protection. The ignition control unit (3) includes a thyristor V2, a resistor-capacitor filter network C2 and R4, a current-limiting resistor R3, a PNP transistor V3, a protection resistor R5, a pull-down resistor R6, and a bypass capacitor C3. The protection resistor R5, pull-down resistor R6 and bypass capacitor C3 are connected in series. The input side of the series connection is connected to the control IO ports P1.1 and P1.2 of the microcontroller (5). The output side is connected to the base and emitter of the PNP transistor V3 respectively. The collector of the PNP transistor V3 is connected in parallel with the current limiting resistor R3, the RC filter network C2 and R4 and then connected to the control electrode of the thyristor V2. The anode of the thyristor V3 is connected to the ignition output voltage of the ignition control unit (3). The cathode of the thyristor V3 is connected to the ignition voltage input terminal of the short circuit protection unit (4).

2. The high-reliability initiation control circuit based on a fuse according to claim 1, characterized in that: The microcontroller (5) is a 32-bit microcontroller based on the M23 core. The microcontroller (5) is equipped with control I / O ports P1.1, P1.2, P2.2 and sampling port P2.

1.

3. The high-reliability initiation control circuit based on a fuse according to claim 1, characterized in that: The charging unit (2) includes a current-limiting resistor R1, a switching diode V1, a charging capacitor C1 and a discharge resistor R2 connected in series. The input side of the series connection is connected to the charging power input terminal VCC2 and the output ground of the linear regulator U1. The output side is connected to the ignition voltage input terminal of the ignition control unit (3). Only when the microcontroller (5) outputs a low level at P1.1, a high level at P1.2 and a low level at P2.2 can the ignition voltage of the charging capacitor C1 be applied to the electric firework.

4. The high-reliability initiation control circuit based on a fuse according to claim 1, characterized in that: The energy storage unit (1) includes Schottky diodes V5, V6, and V7, a current-limiting resistor R11, energy storage capacitors C5 and C6, and a linear regulator U1; The Schottky diodes V5, V6, and V7 are connected in parallel, with their input sides connected to the working power supply input terminal VCC1 and their output sides connected to the input terminal of the linear regulator U1. A current-limiting resistor R11 is connected in series on the input sides of V6 and V7. The energy storage capacitor C5 is connected to the common terminal of Schottky diode V6 and the power supply ground, and the energy storage capacitor C6 is connected to the common terminal of Schottky diode V7 and the power supply ground. The power supply ground is connected to the input terminal of the linear regulator U1.

5. A high reliability initiation control circuit based on a fuze according to claim 4, characterized in that: Schottky diode V5 is a single-tube Schottky diode, while Schottky diodes V6 and V7 are dual-tube Schottky diodes.

6. A high reliability initiation control circuit based on a fuze according to claim 4, characterized in that: The working power input terminal of the energy storage unit (1) is connected to one end of the pull-up resistor R9 of the short-circuit protection unit (4) after passing through Schottky diodes V5, V6, and V7, to provide pull-up voltage.

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