Detection circuit for monitoring automobile collision signal

Abstract

The utility model discloses a detection circuit for monitoring an automobile collision signal. The detection circuit comprises a voltage conversion module, a rectification module, a current-limiting driving module, an isolation driving module, a comparator module and a latch module, the voltage conversion module, the rectification module, the current limiting driving module, the isolation driving module, the comparator module and the latch module are connected in sequence; a collision current signal of a whole vehicle end is input into the voltage conversion module and then is processed by the voltage conversion module, the rectification module, the current limiting driving module, the isolation driving module, the comparator module and the latch module in sequence, and then the latch module outputs the signal. According to the detection circuit for monitoring the automobile collision signal, two groups of backward diodes are additionally arranged at the rear end of the collision signal for rectification processing, so that bidirectional detection of the collision signal is realized, and the use scene of the circuit is widened.

Description

Technical Field

[0001] The utility model belongs to the technical field of automobile collision detection, and in particular relates to a detection circuit for monitoring automobile collision signals. Background Art

[0002] Existing vehicles generally have collision signal detection capabilities. The collision signal input from the vehicle to the BMS is typically in the form of current. This current is converted into a voltage signal by a resistor in the preceding stage. After passing through an integration circuit and a current-limiting drive circuit, the isolated drive module is activated only when its voltage exceeds the threshold voltage of the isolated drive module, preventing collisions caused by normal vehicle movement from triggering the drive signal. Furthermore, the collision signal input and the drive signal are electrically isolated by the isolated drive module, preventing interference caused by differences in reference ground potential due to grounding or other reasons.

[0003] However, existing collision type detection circuits can generally only detect the positive vehicle collision current. In actual applications, it is found that the polarity of the input collision signal varies under different vehicle operating conditions and is not necessarily fixed in the positive direction, which will greatly affect the reliability of the detection circuit. Utility Model Content

[0004] The present invention provides a detection circuit for monitoring automobile collision signals to solve the above-mentioned technical problems, specifically adopting the following technical solutions:

[0005] A detection circuit for monitoring automobile collision signals, comprising: a voltage conversion module, a rectifier module, a current limiting drive module, an isolation drive module, a comparator module and a latch module;

[0006] The voltage conversion module, the rectification module, the current limiting driving module, the isolation driving module, the comparator module and the latch module are connected in sequence;

[0007] The collision current signal at the vehicle end is input to the voltage conversion module, and then processed in sequence by the voltage conversion module, the rectifier module, the current limiting drive module, the isolation drive module, the comparator module and the latch module, and the latch module outputs the signal.

[0008] Furthermore, the voltage conversion module includes a resistor R19, and both ends of the resistor R19 are connected to the signal input port.

[0009] Furthermore, the rectifier module includes a Schottky diode D2, a Schottky diode D4, a Schottky diode D6, a Schottky diode D8 and a resistor R17;

[0010] One end of the resistor R19 is respectively connected to the cathode of the Schottky diode D2 and the anode of the Schottky diode D4, and the other end of the resistor R19 is respectively connected to the cathode of the Schottky diode D8 and the anode of the Schottky diode D6. One end of the resistor R17 is respectively connected to the anode of the Schottky diode D2 and the anode of the Schottky diode D8, and the other end of the resistor R17 is respectively connected to the cathode of the Schottky diode D4 and the cathode of the Schottky diode D6.

[0011] Furthermore, the current limiting driving module includes a resistor R15, a capacitor C16, a diode D5, a capacitor C17, a resistor R20, a resistor R21, a capacitor C18 and a transistor Q2;

[0012] One end of the resistor R15, one end of the capacitor C16, and the positive electrode of the diode D5 are connected to the other end of the resistor R17, the negative electrode of the diode D5 is connected to the capacitor C17 and one end of the resistor R20, the other end of the resistor R20 is connected to the resistor R21, one end of the capacitor C18, and the base of the transistor Q2, and the capacitor C16, the capacitor C17, the resistor R21, the other end of the capacitor C18, and the emitter of the transistor Q2 are connected to one end of the resistor R17.

[0013] Furthermore, the isolation driving module includes an optocoupler isolation chip U4;

[0014] Port 1 of the optocoupler isolation chip U4 is connected to the other end of the resistor R15 , and port 3 of the optocoupler isolation chip U4 is connected to the collector of the transistor Q2 .

[0015] Furthermore, the comparator module includes a resistor R1, a resistor R16, a capacitor C15, a resistor R14, a resistor R22 and a comparator chip U3;

[0016] One end of the resistor R1 is respectively connected to VCC, port 6 of the optocoupler isolation chip U4, the resistor R14, the resistor R22 and port 5 of the comparator chip U3; the other end of the resistor R1 is connected to the resistor R16 and port 5 of the optocoupler isolation chip U4; the other end of the resistor R16 is connected to port 4 of the comparator chip U3 and the capacitor C15; the other end of the capacitor C15 is connected to port 4 of the optocoupler isolation chip U4, port 2 of the comparator chip U3 and ground; the other end of the resistor R14 is connected to port 3 of the comparator chip U3; and the other end of the resistor R22 is connected to port 1 of the comparator chip U3.

[0017] Furthermore, the latch module includes a latch chip U5;

[0018] Port 1 of the latch chip U5 is connected to port 1 of the comparator chip U3, port 2 of the latch chip U5 is grounded, ports 3, 5, and 6 of the latch chip U5 are connected to VCC, and port 4 of the latch chip U5 outputs signals.

[0019] Furthermore, the latch module further comprises a resistor R18;

[0020] Port 4 of the latch chip U5 is connected to the resistor R18 and outputs a signal through the resistor R18.

[0021] The utility model is beneficial in that the detection circuit provided for monitoring automobile collision signals realizes bidirectional detection of collision signals by adding two sets of reverse diodes at the rear end of the collision signal for rectification processing, thereby broadening the application scenarios of this circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application 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 application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0023] Figure 1 This is a schematic diagram of a detection circuit for monitoring automobile collision signals according to the present application. DETAILED DESCRIPTION

[0024] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0025] In the description of this application, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and can refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0026] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0027] like Figure 1 The present invention shows a detection circuit for monitoring automobile collision signals, which includes: a voltage conversion module, a rectifier module, a current limiting drive module, an isolation drive module, a comparator module and a latch module.

[0028] The voltage conversion module, the rectification module, the current limiting drive module, the isolation drive module, the comparator module and the latch module are connected in sequence.

[0029] The collision current signal at the vehicle end is input to the voltage conversion module, and then processed in sequence by the voltage conversion module, rectifier module, current limiting drive module, isolation drive module, comparator module and latch module, and the latch module outputs the signal.

[0030] The voltage conversion module is mainly composed of resistors, and its purpose is to convert the current signal into a voltage signal. Specifically, in the embodiment of the present application, the voltage conversion module includes a resistor R19, and both ends of the resistor R19 are connected to the signal input port.

[0031] The rectifier module is composed of four Schottky diodes and a resistor, and the purpose is to convert voltage signals of different polarities into forward signals for easy processing. In an embodiment of the present application, the rectifier module includes Schottky diode D2, Schottky diode D4, Schottky diode D6, Schottky diode D8 and resistor R17. One end of resistor R19 is respectively connected to the cathode of Schottky diode D2 and the anode of Schottky diode D4, the other end of resistor R19 is respectively connected to the cathode of Schottky diode D8 and the anode of Schottky diode D6, one end of resistor R17 is respectively connected to the anode of Schottky diode D2 and the anode of Schottky diode D8, the other end of resistor R17 is respectively connected to the cathode of Schottky diode D4 and the anode of Schottky diode D6.

[0032] In an embodiment of the present application, the current limiting driving module includes a resistor R15, a capacitor C16, a diode D5, a capacitor C17, a resistor R20, a resistor R21, a capacitor C18, and a transistor Q2. One end of the resistor R15, one end of the capacitor C16, and the positive electrode of the diode D5 are connected to the other end of the resistor R17, the negative electrode of the diode D5 is connected to the capacitor C17 and one end of the resistor R20, the other end of the resistor R20 is connected to the resistor R21, one end of the capacitor C18, and the base of the transistor Q2, and the other ends of the capacitor C16, capacitor C17, resistor R21, capacitor C18, and the emitter of the transistor Q2 are connected to one end of the resistor R17.

[0033] The current-limiting driver module includes voltage divider, integration, and current-limiting driver components. Specifically, resistors R20 and R21 form a voltage divider circuit that divides the voltage signal input from the rectifier module. This allows the voltage triggering transistor Q2 to be set based on the desired threshold. Diode D5 prevents noise on the driver side from affecting the optocoupler driver input. Resistor R15 limits excessive current on the optocoupler driver side. R20 and C18 form an integration circuit (filtering) to trigger the input signal at a specific time.

[0034] The isolation driver module includes an optocoupler isolation chip U4. Port 1 of the optocoupler isolation chip U4 is connected to the other end of the resistor R15, and port 3 of the optocoupler isolation chip U4 is connected to the collector of the transistor Q2.

[0035] In an embodiment of the present application, the comparator module includes a resistor R1, a resistor R16, a capacitor C15, a resistor R14, a resistor R22, and a comparator chip U3. One end of the resistor R1 is connected to VCC, port 6 of the optocoupler isolation chip U4, the resistor R14, the resistor R22, and port 5 of the comparator chip U3, respectively. The other end of the resistor R1 is connected to the resistor R16 and port 5 of the optocoupler isolation chip U4. The other end of the resistor R16 is connected to port 4 of the comparator chip U3 and the capacitor C15. The other end of the capacitor C15 is connected to port 4 of the optocoupler isolation chip U4, port 2 of the comparator chip U3, and ground. The other end of the resistor R14 is connected to port 3 of the comparator chip U3, and the other end of the resistor R22 is connected to port 1 of the comparator chip U3.

[0036] In the embodiment of the present application, the comparator module adopts a hysteresis comparator circuit design. This module introduces a positive feedback network (R22) on the basis of a single threshold voltage comparator with a reverse input to form a reverse input hysteresis comparator with a dual threshold value.

[0037] In the embodiments of the present application, the latch module includes a latch chip U5. Port 1 of latch chip U5 is connected to port 1 of comparator chip U3, port 2 of latch chip U5 is grounded, ports 3, 5, and 6 of latch chip U5 are connected to VCC, and port 4 of latch chip U5 outputs a signal. Furthermore, the latch module also includes a resistor R18. Port 4 of latch chip U5 is connected to resistor R18, and the signal output is performed through resistor R18.

[0038] Specifically, the latch module uses a D flip-flop, and the latching effect is achieved by inputting the signal to be latched on the CP pin side.

[0039] Working principle:

[0040] The vehicle's collision signal is in the form of a current. After this current is input, it passes through resistor R19 in the voltage conversion module, converting it into a voltage signal for subsequent signal processing. The converted voltage signal then passes through the rectifier module, where two sets of oppositely-spaced Schottky diodes handle input voltages of different polarities, outputting them as voltages of the same polarity. R17 prevents excessive impedance at the rear end of the rectifier module from preventing diode D5 from conducting. After the input voltages of different polarities are rectified and driven by a current-limiting driver, the voltage is split into two paths: one to drive transistor Q2 and the other to drive optocoupler isolator U4. Diode D5 ensures unidirectional conductivity and prevents noise from the transistor driver from affecting the optocoupler driver. Resistors R20 and R21 form a voltage divider circuit to divide the input voltage. To turn on transistor Q2, the voltage across R21 must be equal to or greater than the conduction voltage drop across the PN junction of transistor Q2. Adjusting the resistance values ​​of R20 and R21 adjusts the input voltage threshold that triggers the transistor to conduct. R20 and C18 form an integration (filtering) circuit that integrates the input signal and the signal input time. Transistor Q2 is turned on only when the integral value exceeds a preset value, preventing external transient surges from causing malfunction of the collision detection. Resistor R15 acts as a current-limiting resistor to prevent excessive current from driving the optocoupler isolation chip U8.

[0041] When the input circuit of the optocoupler isolation is driven, the output pin is pulled to the ground potential and the output is valid low.

[0042] The comparator module introduces a positive feedback network (R22) to a single-threshold voltage comparator with a reverse input, creating a dual-threshold reverse input hysteresis comparator. This prevents fluctuations in the isolator module's input signal from affecting the comparator's output. The hysteresis comparator's positive feedback network also provides a faster response. Finally, the comparator module's output signal is input to the latch module, which latches the valid signal. The latch module then outputs this stable signal to the MCU, completing the collision signal detection process.

[0043] Beneficial effects of this application:

[0044] This application realizes bidirectional detection of collision signals by rectifying them through two sets of reverse diodes at the back end of the collision signal, thus broadening the application scenarios of this circuit. In addition, a transistor and a diode as well as simple resistors and capacitors are mainly used on the current limiting drive module side to control the input of the isolation drive. The circuit can achieve the effect more simply and save costs. At the same time, a correspondingly faster comparator is used in the output processing at the back end of the isolator, which can transmit signals to the latch module more quickly, reduce delays, and improve the rationality and reliability of the design.

[0045] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the scope of protection of the present invention.

Claims

1. A detection circuit for monitoring automobile collision signals, characterized in that: Contains: voltage conversion module, rectifier module, current limiting drive module, isolation drive module, comparator module and latch module; The voltage conversion module, the rectification module, the current limiting driving module, the isolation driving module, the comparator module and the latch module are connected in sequence; The collision current signal of the vehicle is input to the voltage conversion module, and then processed in sequence by the voltage conversion module, the rectifier module, the current limiting drive module, the isolation drive module, the comparator module and the latch module, and then the latch module outputs the signal; The voltage conversion module includes a resistor R19, and both ends of the resistor R19 are connected to the signal input port; The rectifier module includes a Schottky diode D2, a Schottky diode D4, a Schottky diode D6, a Schottky diode D8 and a resistor R17; One end of the resistor R19 is respectively connected to the cathode of the Schottky diode D2 and the anode of the Schottky diode D4, and the other end of the resistor R19 is respectively connected to the cathode of the Schottky diode D8 and the anode of the Schottky diode D6. One end of the resistor R17 is respectively connected to the anode of the Schottky diode D2 and the anode of the Schottky diode D8, and the other end of the resistor R17 is respectively connected to the cathode of the Schottky diode D4 and the cathode of the Schottky diode D6.

2. The detection circuit for monitoring automobile collision signals according to claim 1, characterized in that: The current limiting driving module includes a resistor R15, a capacitor C16, a diode D5, a capacitor C17, a resistor R20, a resistor R21, a capacitor C18 and a transistor Q2; One end of the resistor R15, one end of the capacitor C16, and the positive electrode of the diode D5 are connected to the other end of the resistor R17, the negative electrode of the diode D5 is connected to the capacitor C17 and one end of the resistor R20, the other end of the resistor R20 is connected to the resistor R21, one end of the capacitor C18, and the base of the transistor Q2, and the capacitor C16, the capacitor C17, the resistor R21, the other end of the capacitor C18, and the emitter of the transistor Q2 are connected to one end of the resistor R17.

3. The detection circuit for monitoring automobile collision signals according to claim 2, characterized in that: The isolation drive module includes an optocoupler isolation chip U4; Port 1 of the optocoupler isolation chip U4 is connected to the other end of the resistor R15 , and port 3 of the optocoupler isolation chip U4 is connected to the collector of the transistor Q2 .

4. The detection circuit for monitoring automobile collision signals according to claim 3, characterized in that: The comparator module includes a resistor R1, a resistor R16, a capacitor C15, a resistor R14, a resistor R22 and a comparator chip U3; One end of the resistor R1 is respectively connected to VCC, port 6 of the optocoupler isolation chip U4, the resistor R14, the resistor R22 and port 5 of the comparator chip U3, the other end of the resistor R1 is connected to the resistor R16 and port 5 of the optocoupler isolation chip U4, the other end of the resistor R16 is connected to port 4 of the comparator chip U3 and the capacitor C15, the other end of the capacitor C15 is connected to port 4 of the optocoupler isolation chip U4, port 2 of the comparator chip U3 and ground, the other end of the resistor R14 is connected to port 3 of the comparator chip U3, and the other end of the resistor R22 is connected to port 1 of the comparator chip U3.

5. The detection circuit for monitoring automobile collision signals according to claim 4, characterized in that: The latch module includes a latch chip U5; Port 1 of the latch chip U5 is connected to port 1 of the comparator chip U3, port 2 of the latch chip U5 is grounded, ports 3, 5, and 6 of the latch chip U5 are connected to VCC, and port 4 of the latch chip U5 outputs signals.

6. The detection circuit for monitoring automobile collision signals according to claim 5, characterized in that: The latch module further includes a resistor R18; Port 4 of the latch chip U5 is connected to the resistor R18 and outputs a signal through the resistor R18.

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