Anti-electromagnetic interference system for anti-explosion vehicle-mounted control unit of anti-explosion industrial vehicle

Abstract

The utility model discloses an anti-electromagnetic interference system for an anti-explosion vehicle-mounted control unit of an anti-explosion industrial vehicle, and relates to the technical field of special operation vehicles. According to the utility model, a parallel double-loop structure is additionally arranged at the output end of the photoelectric coupler of the vehicle-mounted control unit, the first loop transmits an output signal to the motor driving controller, and the second loop is directly grounded through the pull-down resistor. When the driving motor generates a strong electromagnetic field, parasitic charges formed by interference signals at the output end of the photoelectric coupler are quickly discharged through the low-impedance pull-down resistor, so that the potential of the input port of the controller is always lower than a logic low-level threshold value, and false triggering when no input signal exists is blocked; meanwhile, the forward rotation signal loop and the reverse rotation signal loop adopt independent photoelectric couplers and pull-down resistors, the reference potential is unified through common ground design, and cross interference is avoided. The industrial problem that electromagnetic interference cannot be effectively shielded due to space limitation in a traditional scheme is solved, and the control reliability and the operation safety of the anti-explosion industrial vehicle in an explosive environment are remarkably improved.

Description

Technical Field

[0001] This utility model relates to the field of special operation vehicle technology, and in particular to an anti-electromagnetic interference system for an explosion-proof industrial vehicle on-board control unit. Background Technology

[0002] As special equipment operating in explosive hazardous environments, explosion-proof industrial vehicles require their electrical control systems to meet stringent explosion-proof safety requirements. Currently, the commonly used technical solution in the industry is to encapsulate the on-board control unit within an explosion-proof cavity, using optocouplers to achieve physical isolation between input signals (low-voltage safety side) and output signals (high-voltage drive side), thereby blocking potential electrical spark propagation paths.

[0003] In practice, explosion-proof vehicle-mounted control units are typically positioned above the drive motor to save space. Their core component, the optocoupler (e.g., DIP / SOP packaged models), achieves high- and low-voltage circuit isolation through non-contact coupling between an input-side LED and an output-side phototransistor. When an external switch (e.g., a forward / reverse switch) is closed, the low-voltage signal on the input side drives the LED to illuminate, triggering the output-side phototransistor to conduct, thereby sending control commands to the motor driver. Theoretically, this design can meet explosion-proof requirements while also ensuring reliable transmission of control signals.

[0004] However, when the drive motor is running, its rotating magnetic field induces parasitic currents inside the vehicle control unit. In particular, the output transistor of the optocoupler (such as an NPN type) may mis-convert under the influence of a strong magnetic field, even without a signal on the input side, due to the electromotive force induced by the magnetic field. For example, after the forward switch is turned off, a residual voltage may remain at the output of the optocoupler, causing the controller to misinterpret the forward command as continuing, creating a logical conflict with the reverse command and triggering a system malfunction. Utility Model Content

[0005] The purpose of this invention is to provide an anti-electromagnetic interference system for an explosion-proof on-board control unit of an explosion-proof industrial vehicle, so as to solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, this utility model adopts the following technical solution: an anti-electromagnetic interference system for an explosion-proof industrial vehicle's on-board control unit, comprising a peripheral switch input module, an on-board control unit, a motor drive controller, and a drive motor connected in sequence, and a battery providing power to the peripheral switch input module, the on-board control unit, and the motor drive controller; the on-board control unit includes a first optocoupler and a second optocoupler; the input end of the first optocoupler is connected to a peripheral forward switch input module, and the output end is connected to the input port of the motor drive controller and a first pull-down resistor respectively through a parallel double circuit; the first end of the first pull-down resistor is connected to the output end of the first optocoupler, and the second end is grounded, forming an electromagnetic interference signal discharge circuit; the input end of the second optocoupler is connected to a peripheral reverse switch input module, and the output end is connected to the input port of the motor drive controller and a second pull-down resistor respectively through a parallel double circuit; the first end of the second pull-down resistor is connected to the output end of the second optocoupler, and the second end is grounded, forming an electromagnetic interference signal discharge circuit.

[0007] Preferably, the output terminal of the first optocoupler includes port 3 and port 4. Port 3 of the first optocoupler is connected to port J1 of the motor drive controller, and port 4 is connected to port J2 of the motor drive controller. When port J2 receives a signal, it is used to control the forward rotation of the drive motor. The first pull-down resistor is connected to port 4 of the second optocoupler in parallel.

[0008] More preferably, the output terminal of the second optocoupler includes port 3 and port 4. Port 3 of the second optocoupler is connected to port J1 of the motor drive controller, and port 4 is connected to port J3 of the motor drive controller. When port J3 receives a signal, it is used to control the drive motor to reverse. The second pull-down resistor is connected to port 4 of the second optocoupler in parallel.

[0009] More preferably, the first optocoupler, the second optocoupler, the first pull-down resistor, and the second pull-down resistor are integrated on the same PCB circuit board.

[0010] More preferably, the vehicle control unit is located directly above the drive motor.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0012] By setting parallel dual-loop structures (i.e., a signal loop connected to the input port of the motor drive controller and a discharge loop connected to the pull-down resistor) at the output terminals of the first and second optocouplers, when the drive motor generates a strong electromagnetic field, the parasitic charge formed at the output terminals of the optocouplers by the interference signal can be quickly discharged to ground through the first and second pull-down resistors. For example, when the forward switch is turned off, even if the motor magnetic field induces an abnormal voltage at the output terminal of the first optocoupler, this voltage will be discharged to ground through the pull-down resistor, stabilizing the output terminal potential at a logic low level. This prevents the controller from mistakenly judging that the forward signal continues to exist, thereby resolving system faults caused by forward / reverse command conflicts. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the system framework in the embodiment;

[0014] Figure 2 This is a schematic diagram of the system principle in the embodiment.

[0015] In the picture:

[0016] 1 — Vehicle control unit 2 — Motor drive controller

[0017] 3 — Drive motor 4 — First optocoupler

[0018] 5—Second optocoupler. Detailed Implementation

[0019] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0020] like Figure 1 and Figure 2 As shown, an anti-electromagnetic interference system for an explosion-proof industrial vehicle's on-board control unit includes a peripheral switch input module, an on-board control unit 1, a motor drive controller 2, and a drive motor 3 connected in sequence. It also includes a battery that provides power to the peripheral switch input module, the on-board control unit 1, and the motor drive controller 2. The on-board control unit includes a first optocoupler 4 and a second optocoupler 5.

[0021] In the above structure, the input end of the first optocoupler 3 is connected to the peripheral forward switch input module (shown as K1 in the figure), and the output end is connected to the input port of the motor drive controller 2 and the first pull-down resistor (shown as R1 in the figure) through parallel double loops. The first end of the first pull-down resistor is connected to the output end of the first optocoupler 3, and the second end is grounded, forming an electromagnetic interference signal discharge loop.

[0022] The input terminal of the second optocoupler 4 is connected to the external reverse switch input module (shown as K2 in the attached figure), and the output terminal is connected to the input port of the motor drive controller 2 and the second pull-down resistor (shown as R2 in the attached figure) through parallel double loops. The first end of the second pull-down resistor is connected to the output terminal of the second optocoupler, and the second end is grounded, forming an electromagnetic interference signal discharge loop.

[0023] Furthermore, the output of the first optocoupler includes port 3 and port 4. Port 3 of the first optocoupler is connected to port J1 of the motor drive controller, and port 4 is connected to port J2 of the motor drive controller. When port J2 receives a signal, it is used to control the forward rotation of the drive motor. The first pull-down resistor is connected to port 4 of the second optocoupler in parallel.

[0024] By connecting port 4 (output) of the first optocoupler to port J2 (forward signal receiver) of the motor drive controller, and connecting a first pull-down resistor in parallel with port 4, a dual-path "signal output + interference discharge" is formed: when the forward switch is closed, port 4 outputs a high level to drive port J2 to trigger the forward command; when the forward switch is open, the interference voltage generated by the magnetic field of the drive motor at port 4 is quickly discharged to ground through the first pull-down resistor, ensuring that the potential of port J2 is stable at a logic low level and eliminating the problem of "virtual voltage residue" caused by electromagnetic interference. At the same time, port 3 of the first optocoupler is directly connected to port J1 (common terminal) to provide a stable reference potential for the output circuit, which can avoid signal drift caused by ground line floating.

[0025] Meanwhile, the output of the second optocoupler includes port 3 and port 4. Port 3 of the second optocoupler is connected to port J1 of the motor drive controller, and port 4 is connected to port J3 of the motor drive controller. When port J3 receives a signal, it is used to control the reverse rotation of the drive motor. The second pull-down resistor is connected to port 4 of the second optocoupler in parallel.

[0026] The second optocoupler's port 4 is connected to port J3 (reverse signal receiver), and a second pull-down resistor is independently configured to achieve physical isolation and independent interference handling for the forward / reverse signal circuits: when the reverse switch is activated, the second pull-down resistor only directionally discharges interference from the circuit containing port J3, preventing interference signals from the forward circuit from coupling to the reverse circuit through the common terminal of J1. Furthermore, ports 3 of both the forward and reverse optocouplers are connected to the same port J1, unifying the signal reference ground. This simplifies the circuit layout and prevents potential difference interference caused by multiple grounding points, ensuring the controller accurately identifies the synchronous forward (J2) and reverse (J3) signals.

[0027] Furthermore, in this embodiment, the first optocoupler, the second optocoupler, the first pull-down resistor, and the second pull-down resistor are integrated on the same PCB circuit board. This integrated design ensures that the ground wires of the two signal discharge circuits are connected at a common point, eliminating potential differences caused by multiple grounding points. This improves the discharge efficiency of the pull-down resistors against interference voltage, balancing anti-interference performance with the miniaturization requirements of the explosion-proof vehicle control unit. This allows the vehicle control unit to be directly positioned above the drive motor.

[0028] The anti-electromagnetic interference system for explosion-proof industrial vehicle on-board control units provided in the above embodiment, based on the input-output physical isolation characteristics of optocouplers, adds a parallel dual-loop structure to the output terminal of the optocoupler of the on-board control unit: the first loop transmits the output signal to the motor drive controller, and the second loop is directly grounded through a pull-down resistor. When the drive motor generates a strong electromagnetic field, the parasitic charge formed at the output terminal of the optocoupler by the interference signal is quickly discharged through the low-impedance pull-down resistor, ensuring that the potential of the controller input port is always below the logic low-level threshold, thereby blocking false triggering when there is no input signal; at the same time, the forward and reverse signal loops use independent optocouplers and pull-down resistors, and a common ground design with a unified reference potential avoids cross-interference.

[0029] This invention eliminates signal drift and malfunctions caused by electromagnetic interference through the coordinated use of a dual-loop system of "signal transmission + dynamic discharge," greatly reducing the false flux rate of the optocoupler output under a strong magnetic field. The independent discharge circuit and PCB integration design significantly improve the discharge efficiency of interference charge, balancing anti-interference performance with the miniaturization requirements of the explosion-proof cavity. It solves the industry problem that traditional solutions cannot effectively shield electromagnetic interference due to space limitations, and significantly improves the control reliability and operational safety of explosion-proof industrial vehicles in explosive environments.

[0030] To facilitate understanding by those skilled in the art of the improvements of this utility model compared to the prior art, some of the accompanying drawings and descriptions of this utility model have been simplified. The above embodiments are preferred implementations of this utility model. In addition, this utility model can be implemented in other ways. Any obvious substitutions without departing from the concept of this technical solution are within the protection scope of this utility model.

Claims

1. An anti-electromagnetic interference system for an explosion-proof industrial vehicle's on-board control unit, characterized in that: It includes a peripheral switch input module, an on-board control unit, a motor drive controller, and a drive motor connected in sequence, and also includes a battery that provides power to the peripheral switch input module, the on-board control unit, and the motor drive controller; The vehicle control unit includes a first optocoupler and a second optocoupler; The input end of the first optocoupler is connected to the external forward switch input module, and the output end is connected to the motor drive controller input port and the first pull-down resistor respectively through parallel double circuits. The first end of the first pull-down resistor is connected to the output end of the first optocoupler, and the second end is grounded, forming an electromagnetic interference signal discharge circuit. The input terminal of the second optocoupler is connected to the external reverse switch input module, and the output terminal is connected to the motor drive controller input port and the second pull-down resistor respectively through parallel dual circuits. The first end of the second pull-down resistor is connected to the output terminal of the second optocoupler, and the second end is grounded, forming an electromagnetic interference signal discharge circuit.

2. The anti-electromagnetic interference system for explosion-proof industrial vehicle on-board control unit according to claim 1, characterized in that: The first optocoupler has an output terminal including port 3 and port 4. Port 3 of the first optocoupler is connected to port J1 of the motor drive controller, and port 4 is connected to port J2 of the motor drive controller. When port J2 receives a signal, it is used to control the forward rotation of the drive motor. The first pull-down resistor is connected to port 4 of the second optocoupler in parallel.

3. The anti-electromagnetic interference system for explosion-proof industrial vehicle on-board control unit according to claim 2, characterized in that: The output terminals of the second optocoupler include port 3 and port 4. Port 3 of the second optocoupler is connected to port J1 of the motor drive controller, and port 4 is connected to port J3 of the motor drive controller. When port J3 receives a signal, it is used to control the drive motor to reverse. The second pull-down resistor is connected to port 4 of the second optocoupler in parallel.

4. The anti-electromagnetic interference system for explosion-proof industrial vehicle on-board control unit according to claim 3, characterized in that: The first optocoupler, the second optocoupler, the first pull-down resistor, and the second pull-down resistor are integrated on the same PCB circuit board.

5. The anti-electromagnetic interference system for explosion-proof industrial vehicle on-board control unit according to any one of claims 1-4, characterized in that: The vehicle control unit is located directly above the drive motor.

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