Machine gun electric filling driving and protecting device

Abstract

The invention relates to the technical field of firearms, in particular to a machine gun electric filling driving and protecting device which comprises an MCU, a power input assembly, an H-bridge circuit, a driving circuit, a buffer circuit, a PWM, a current sampling circuit, an overcurrent protection circuit and a control signal module, the power input assembly is connected with the H-bridge circuit, the driving circuit and the current sampling circuit are both connected with the H-bridge circuit, and the buffer circuit is connected with the PWM. The buffer circuit is connected with the driving circuit and the PWM, the PWM is further connected with the MCU, the current sampling circuit is further connected with the MCU, the overcurrent protection circuit is connected with the buffer circuit, the current sampling circuit and the MCU, and the control signal module is connected with the MCU, so that the technical problems that in the prior art, electric filling is low in reliability and does not have a self-protection function are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of firearms, and in particular to an electric loading, driving and protecting device for a machine gun. Background Art

[0002] Currently, electric reloading is an essential feature for remote-controlled weapon stations and unmanned strike equipment for small arms. Traditionally, electric reloading control and drive are integrated into the main control unit (MCU). Different weapon calibers require different reloading control and drive requirements, resulting in the need for custom development of MCUs for specific calibers. This results in relatively poor scalability and compatibility. Currently, the electric reloading control and drive systems in service or exported equipment are relatively simple and crude. Most systems utilize feedback from the reloading mechanism's sensor status to directly control the on / off state of power devices such as MOSFETs and relays to provide the rated forward and reverse voltages for the reloading motor. This approach fails to adequately account for motor stalls caused by misoperation, such as machine gun failure, mismatched ammunition belts, or foreign objects stuck in the reloading mechanism. Furthermore, operating conditions in full temperature environments are a concern. As a result, current remote-controlled weapons frequently experience damage to the reloading mechanism, reloading motor, and power components due to reloading jams, as well as damage caused by heat accumulation in high-temperature environments. The reliability of electric reloading urgently needs to be improved.

[0003] At the same time, in order to adapt to the rapid development of light weapons towards unmanned equipment, higher requirements are placed on the loading mechanism in terms of scalability and compatibility. The loading mechanism is not just a traditional terminal electromechanical combination component. It currently needs to be integrated into the system master control as an independent node. The master control can conveniently realize the loading function through general I / O or bus. The loading mechanism needs to have independent control, drive, protection and fault diagnosis capabilities, and can effectively implement protection when loading is abnormal, while protecting the mechanism itself from damage and causing no damage to the system. However, the current domestic research and practice on the integration of loading mechanisms as independent nodes into weapon equipment systems is relatively scarce.

[0004] In summary, the electric loading method in the prior art has low reliability and does not have a self-protection function. Summary of the Invention

[0005] The purpose of the present invention is to provide a machine gun electric loading drive and protection device, aiming to solve the technical problems in the existing technology that the electric loading method has low reliability and does not have a self-protection function.

[0006] To achieve the above-mentioned objectives, the present invention adopts a machine gun electric loading drive and protection device, including an MCU, a power input component, an H-bridge circuit, a drive circuit, a buffer circuit, a PWM, a current sampling circuit, an overcurrent protection circuit and a control signal module. The power input component is connected to the H-bridge circuit, the drive circuit and the current sampling circuit are both connected to the H-bridge circuit, the buffer circuit is both connected to the drive circuit and the PWM, the PWM is also connected to the MCU, the current sampling circuit is also connected to the MCU, the overcurrent protection circuit is connected to the buffer circuit, the current sampling circuit and the MCU, and the control signal module is connected to the MCU.

[0007] The power input component includes a power input module and a power circuit, and both the power input module and the power circuit are connected to the H-bridge circuit.

[0008] Wherein, the MCU adopts STM32F103 single chip microcomputer.

[0009] Among them, the machine gun electric loading drive and protection device is installed in the machine gun loading unit to form a mechatronic loading control module, realizing the terminal independent loading function or modularly integrated and installed in the main control unit to realize centralized control.

[0010] Specifically, the present invention first analyzes the first-shot loading principles of machine guns of different calibers, collects and tests the existing first-shot loading electric drive forms and power consumption during actual loading, and designs the working principles of the present invention to provide support for the hardware design and software design of the device.

[0011] Then, according to the loading principle and actual loading power consumption, PCB design is carried out: including MCU control circuit, PWM buffer and power drive circuit, H-bridge drive circuit, current and temperature sampling circuit and hardware overcurrent protection circuit; Further, based on the loading principle and actual loading power consumption, software design is carried out: including main function control design, PWM drive interface design, multi-channel ADC data acquisition and DMA transmission design, and control algorithm design; Finally, we conducted tests to verify the loading jam protection function using firearms of typical calibers under normal and high temperature conditions, including situations where the machine gun was not properly loaded, the ammunition belt did not match, and foreign objects were stuck in the loading mechanism. The following data was collected during loading tests on a 12.7mm caliber machine gun: Tests were conducted at both room temperature and 65°C (144°F) using standard on-board 24V power supplies, extreme 18V power supplies, and 30V power supplies. 180 loading stall tests were conducted at both room and high temperature, for a total of 360 stall tests. Throughout the tests, when the loading motor stalled, the current closed-loop protection was promptly triggered, and no electrical components exhibited burnout. The weapon station functioned normally, demonstrating the effectiveness of the protective measures.

[0012] The present invention provides an electric loading drive and protection device for machine guns. It features power-on slow start and overcurrent, overtemperature, and overload protection measures. This prevents stalling of the loading mechanism, which could damage the loading mechanism, loading motor, and power components, thereby improving the reliability of the equipment. This device utilizes universal hardware and software design, enabling first-shot loading for machine guns of varying calibers and offering high versatility.

[0013] The independent "node-type" device proposed in this invention can be easily connected to the main control system of weapons and equipment, and has strong system expansion and compatibility. This method solves the technical problems of the existing electric loading method with low reliability and lack of self-protection function. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 It is a principle block diagram of the electric loading drive and protection device for a machine gun of the present invention.

[0016] Figure 2 This is a control principle diagram of the electric loading drive and protection device for a machine gun of the present invention.

[0017] Figure 3 This is a schematic diagram of the MCU control principle of the device hardware of the present invention.

[0018] Figure 4 This is a schematic diagram of the hardware PWM buffer and power drive circuit of the device of the present invention.

[0019] Figure 5 This is a schematic diagram of the hardware overcurrent protection and temperature sampling circuit of the device of the present invention.

[0020] Figure 6 It is a software flow chart of the device of the present invention. DETAILED DESCRIPTION

[0021] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0022] See also Figures 1 to 6 ,in Figure 1 It is a principle block diagram of the electric loading drive and protection device for a machine gun of the present invention. Figure 2This is a control principle diagram of the electric loading drive and protection device for a machine gun of the present invention. Figure 3 This is a schematic diagram of the MCU control principle of the device hardware of the present invention. Figure 4 This is a schematic diagram of the hardware PWM buffer and power drive circuit of the device of the present invention. Figure 5 This is a schematic diagram of the hardware overcurrent protection and temperature sampling circuit of the device of the present invention. Figure 6 It is a software flow chart of the device of the present invention.

[0023] The present invention provides a machine gun electric loading drive and protection device, comprising an MCU, a power input component, an H-bridge circuit, a drive circuit, a buffer circuit, a PWM, a current sampling circuit, an overcurrent protection circuit, and a control signal module. The power input component is connected to the H-bridge circuit, the drive circuit and the current sampling circuit are both connected to the H-bridge circuit, the buffer circuit is both connected to the drive circuit and the PWM, the PWM is also connected to the MCU, the current sampling circuit is also connected to the MCU, the overcurrent protection circuit is connected to the buffer circuit, the current sampling circuit, and the MCU, and the control signal module is connected to the MCU.

[0024] The power input component includes a power input module and a power circuit, and both the power input module and the power circuit are connected to the H-bridge circuit.

[0025] Wherein, the MCU adopts STM32F103 single chip microcomputer.

[0026] Among them, the machine gun electric loading drive and protection device is installed in the machine gun loading unit to form a mechatronic loading control module, realizing the terminal independent loading function or modularly integrated and installed in the main control unit to realize centralized control.

[0027] In response to the low reliability of existing electric loading methods, the present invention improves reliability during abnormal loading by adding soft start and overload and overcurrent protection measures. The overall design concept is as follows: 1) After receiving external input of forward, reverse, and enable commands, the machine gun electric loading drive and protection device detects the current passing through the motor in real time, adjusts the output PWM signal, and controls the operation of the loading motor; 2) During the process of starting or stopping the motor, the PWM signal pulse width is gradually adjusted. The starting process is slow to prevent the motor from starting too fast, and the stopping process reduces the impact on the power supply when the motor stops; 3) Real-time detection of motor current and power board temperature. When the motor current exceeds the maximum set value, the software overcurrent protection is triggered. When the motor current exceeds the hardware protection value, the hardware overcurrent protection is triggered. When the average motor current over a period of time exceeds the set value, the software overload protection is triggered. 4) When the power board temperature exceeds the set value, the over-temperature protection is triggered. After the above protection occurs, the driver module fault feedback signal outputs a high level. After powering off and restarting the device, the fault disappears.

[0028] See also Figure 3 , Figure 3 This is the hardware MCU control principle diagram of the device of the present invention; The MCU uses STM32F103, and the minimum system consists of a clock circuit, a reset circuit, a power supply circuit, and a boot circuit. It is mainly used to receive loading control instructions, feedback loading status, and output loading control signals. The core control function is the PWM output function, which is implemented as follows: 1) The core control logic deeply encapsulates the timer (TIM) module through the STM32 HAL library, achieving high-precision PWM waveform generation and dynamic duty cycle adjustment. Symmetrical counting (up / down counting) generates symmetrical PWM waveforms, significantly reducing electromagnetic interference (EMI) during motor drive. The system clock source is 72MHz, and a 10kHz PWM signal is generated by configuring the prescaler value (Prescaler=35) and the auto-reload value (Period=99). The 10Khz frequency takes into account both the smoothness of the motor drive and the optimization of switching losses. The duty cycle can be adjusted in real time by directly operating the timer compare register (CCR); 2) Configure the dead time to 71 clock cycles (about 1 μs) through the TIM_BreakDeadTimeConfig structure to ensure that there is no risk of overlapping conduction when switching between the upper and lower transistors in the H-bridge circuit, thereby avoiding short-circuit damage; 3) When the motor starts, the duty cycle increases in 1% steps to avoid current shock and gradually increases to the target value to achieve a slow start; 4) Dynamically adjust the duty cycle based on real-time current feedback. For example, when a sudden load increase is detected, the duty cycle is automatically increased to maintain a stable speed, achieving load adaptive regulation. 5) Multi-channel complementary output PWM configuration: TIM1 channel 1 and channel 1N (PA7), and channel 2 and channel 2N (PB0) form complementary PWM pairs to drive the forward and reverse logic of the H-bridge circuit. Enabling the complementary channels through the HAL_TIMEx_PWMN_Start() function ensures hardware-level synchronization of motor direction control.

[0029] See also Figure 4 , Figure 4 This is a schematic diagram of the hardware PWM buffer and power drive circuit of the device of the present invention.

[0030] The MOS driver chip used is the EG3112, a half-bridge driver with interlocking protection for the upper and lower transistors. The PWM signal output by the MCU is transmitted to the MOS driver chip EG3112 through the RS8T245 buffer chip. The RS8T245's OE pin controls the output enable signal. When high, the output level is in a high-impedance state. By controlling this pin, the PWM signal can be quickly disconnected.

[0031] Because most loading motors are brushed DC motors with high stall currents, the circuit uses a dual MOS parallel drive solution to improve the safety margin of the drive hardware. The circuit design uses the NCEP065N12 MOS transistor, which has a maximum voltage resistance of 120V and a maximum current of 64A at 100°C. This meets the design's 24V, 750W drive requirements for the loading motors.

[0032] See also Figure 5 , Figure 5 This is a schematic diagram of the hardware overcurrent protection and temperature sampling circuitry of the device of the present invention. The machine gun electric loading drive and protection device includes two current sampling circuits to collect bus current and motor phase current. The current sampling chip used is the CC6920BSO-50A, a bidirectional current sampling chip with a zero current center value of 1.65V and a current resolution of 26.4mV / A. The power board temperature is collected via a thermistor.

[0033] The current sensor outputs signals to the MCU and comparator input terminals respectively. When the current exceeds the comparator setting value, the comparator outputs a high level and turns off the buffer chip PWM output. After the MCU receives the interrupt signal, it also turns off the PWM signal to play an overcurrent protection role.

[0034] To achieve high-precision current and temperature monitoring, ADC sampling uses the STM32 ADC module and DMA controller to build an efficient data acquisition architecture as follows: 1) ADC hardware configuration: Dual-channel scanning mode: Configure ADC1's channel 1 (PA1, current detection) and channel 5 (PA5, temperature detection) to continuous scanning mode. Optimize sampling time: Set the sampling time for each channel to 1.5 ADC clock cycles (ADC_SAMPLETIME_1CYCLE_5) and a single sampling time of 0.02 μs to balance speed and accuracy requirements. 2) DMA circular buffer mode: DMA1 channel 1 is configured in circular transfer mode (DMA_CIRCULAR) to achieve uninterrupted transmission of ADC data. The memory address is automatically incremented, and the storage structure is uint16_t adcConvertedValue[2], where index 0 is the current value and index 1 is the temperature value; 3) Temperature lookup table, filtering method: NTC characteristic table storage: predefined tempTable[] array, which stores the mapping relationship between ADC value and temperature, covering the range of -27°C to 150°C; Binary fast search: efficient temperature query is achieved through binarySearch() function; Finally, the real-time sampling values ​​are weighted filtered to suppress high-frequency noise and realize the first-order filtering algorithm.

[0035] See also Figure 6 , Figure 6 It is a software flow chart of the device of the present invention.

[0036] This paper designs DC motor loading control software based on an STM32 microcontroller, particularly suitable for high-precision, high-reliability loading scenarios. Through hardware abstraction layer design, multi-channel real-time data acquisition, a dynamic PI control algorithm, and a hierarchical fault protection mechanism, the software achieves precise control of the motor drive and rapid response to abnormalities. Upon receiving enable and forward and reverse control signals, the software controls the DC motor to operate in the set direction of motion. It also provides a motor power-on slow start function, as well as overcurrent protection, overload protection, and overtemperature protection.

[0037] The software is specifically implemented as follows: (1) System Architecture a. Hardware Abstraction Layer (HAL) design: decoupling hardware drivers from upper-layer logic; b. Dynamic PI control algorithm: Anti-integral saturation design combined with sliding average filtering improves control accuracy and dynamically adjusts PWM duty cycle; c. Multi-level fault protection mechanism: software overcurrent, hardware overcurrent, and overtemperature protection layered triggering; d. Real-time data acquisition architecture: DMA-based ADC dual-channel synchronous sampling reduces CPU load.

[0038] (2) Main function control design 2.1 Initialization phase a. Slow start on power-up: The program waits for 100ms delay to allow the hardware capacitor to charge and avoid current surge; b. Initialize timers TIM1, TIM2, and TIM3: TIM1 is used as the motor PWM output, TIM2 is used as a soft start to adjust the duty cycle, and TIM3 is used to count the working time; c. ADC and DMA initialization: ADC channels CH1 (motor current) and CH5 (temperature) are continuously scanned with 12-bit resolution; d.DMA transfer: After the ADC conversion is complete, the data is automatically stored in the adcConvertedValue[] array via DMA, corresponding to temperature and motor current, respectively. Real-time current and temperature data is collected for overcurrent, overload, and overtemperature protection.

[0039] 2.2 Main loop phase a. Read command function. Read the enable, forward, and reverse signals from the external servo control board. If both the forward and reverse signals are received simultaneously, a fault state is set. The enable signal takes priority; if not, the stop function is executed directly.

[0040] b. Motor processing function. Enable judgment: If not enabled, call the stop function; if enabled, set the working state according to the forward / reverse signal.

[0041] Forward: clear the IO port of XL, set WL high, and XH outputs PWM; Reverse: clear the IO port of WL, set XL high, and WH outputs PWM; Stop: All PWM duty cycles are cleared and IO ports are reset.

[0042] c. Current and temperature calculation: Obtain a stable average value of the ADC raw value multiple times and convert it into actual current (mA) and temperature (°C).

[0043] d. Overload protection flag (ol_Flag). After entering the 1ms count (for debounce or delay), if the current current ≥ the target current, the overload flag is triggered. Protection action: Set the fault flag, clear the PWM duty cycle, and stop the motor. Accumulated overload / overcurrent / overtemperature: If any of these protection conditions are triggered, the fault pin (Fault) is set high, stopping the motor.

[0044] e.PI algorithm adjusts PWM. Based on the difference between the current and the target current, the PI control algorithm dynamically adjusts the PWM duty cycle to achieve current closed-loop control.

[0045] f. Status check and protection: TIM3 performs periodic checks. If the motor runs continuously for more than 15 seconds, a timeout flag is returned.

[0046] (3) Control algorithm design Implementation of dynamic PI control algorithm and anti-saturation design: An improved PI controller is used. The PI (proportional-integral) algorithm is a classic control strategy that dynamically adjusts the system output to approach the target value by combining proportional control and integral control. Its combination of real-time feedback and anti-integral windup strategy can significantly improve control accuracy.

[0047] The total output formula of the PI algorithm is as follows:

[0048] Ki: Integral gain, which determines the compensation strength for the accumulated error; : The integral of the error from the initial moment to the current moment.

[0049] b. PI output calculation and limiting Error calculation and integral management in the program: For target current setting, the target current value (TARGET_CURRENT) is dynamically set according to the loading task requirements. For example, setting 18A corresponds to medium load conditions, and to prevent the integral term from overflowing, the integral value is hard-limited.

[0050] Control quantity synthesis: weighted sum of proportional term and integral term to generate PWM duty cycle instruction; Output limit protection: Ensures that the PWM value is within a safe range.

[0051] c Dynamic parameter adjustment strategy: Load Adaptation: Dynamically adjusts the Kp / Ki parameters based on the deviation between the motor's real-time current and the target. For example, if the error exceeds 2A, Kp is automatically increased to improve response speed.

[0052] Anti-disturbance design: Introduce feedforward compensation items to preload the impact of known load changes (such as sudden changes in material density) on the control quantity and reduce overshoot.

[0053] The electric loading drive and protection device for machine guns of this embodiment provides power-on slow start and overcurrent, overtemperature, and overload protection measures, preventing loading mechanism stalls that could damage the loading mechanism, loading motor, and power components, thereby improving equipment loading reliability. This device utilizes universal hardware and software design, enabling first-shot loading for machine guns of varying calibers and offering high versatility.

[0054] The independent "node-type" device proposed in this invention can be easily connected to the main control system of weapons and equipment, and has strong system expansion and compatibility. This method solves the technical problems of the existing electric loading method with low reliability and lack of self-protection function.

[0055] Specifically, the present invention first analyzes the first-shot loading principles of machine guns of different calibers, collects and tests the existing first-shot loading electric drive forms and power consumption during actual loading, and designs the working principles of the present invention to provide support for the hardware design and software design of the device.

[0056] Then, according to the loading principle and actual loading power consumption, PCB design is carried out: including MCU control circuit, PWM buffer and power drive circuit, H-bridge drive circuit, current and temperature sampling circuit and hardware overcurrent protection circuit; Further, based on the loading principle and actual loading power consumption, software design is carried out: including main function control design, PWM drive interface design, multi-channel ADC data acquisition and DMA transmission design, and control algorithm design; Finally, we conducted tests to verify the loading jam protection function using firearms of typical calibers under normal and high temperature conditions, including situations where the machine gun was not properly loaded, the ammunition belt did not match, and foreign objects were stuck in the loading mechanism. The following data was collected during loading tests on a 12.7mm caliber machine gun: Tests were conducted at both room temperature and 65°C (144°F) using standard on-board 24V power supplies, extreme 18V power supplies, and 30V power supplies. 180 loading stall tests were conducted at both room and high temperature, for a total of 360 stall tests. Throughout the tests, when the loading motor stalled, the current closed-loop protection was promptly triggered, and no electrical components exhibited burnout. The weapon station functioned normally, demonstrating the effectiveness of the protective measures.

[0057] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of the rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A machine gun electric loading drive and protection device, characterized in that: It includes an MCU, a power input component, an H-bridge circuit, a drive circuit, a buffer circuit, a PWM, a current sampling circuit, an overcurrent protection circuit and a control signal module. The power input component is connected to the H-bridge circuit, the drive circuit and the current sampling circuit are both connected to the H-bridge circuit, the buffer circuit is connected to the drive circuit and the PWM, the PWM is also connected to the MCU, the current sampling circuit is also connected to the MCU, the overcurrent protection circuit is connected to the buffer circuit, the current sampling circuit and the MCU, and the control signal module is connected to the MCU.

2. The machine gun electric loading drive and protection device according to claim 1, characterized in that: The power input component includes a power input module and a power circuit, and both the power input module and the power circuit are connected to the H-bridge circuit.

3. The machine gun electric loading drive and protection device according to claim 2, characterized in that: The machine gun electric loading drive and protection device is installed in the machine gun loading unit to form a mechatronic loading control module.

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