Direct current motor self-checking circuit for electronic parking system

Abstract

The utility model discloses a direct current motor self-checking circuit for an electronic parking system, which belongs to the field of automobile electronic control, and comprises a positive end sampling loop ADH and a negative end sampling loop ADL which are connected to two ends of an EPB motor, and a self-checking loop connected to the negative end sampling loop ADL, the self-checking loop comprises an NPN triode Q1 and a PNP triode Q2, and the positive end sampling loop ADH and the negative end sampling loop ADL are connected to the negative end sampling loop ADL. The base electrode of the NPN triode Q1 is connected with a single-chip microcomputer used for outputting PWM waves, the emitter electrode of the NPN triode Q1 is grounded, the collector electrode of the NPN triode Q1 is connected with the base electrode of the PNP triode Q2, the collector electrode of the PNP triode Q2 is connected with the power supply end Vin, and the emitter electrode of the PNP triode Q2 is connected to the negative end sampling loop ADL. By adopting the direct current motor self-checking circuit for the electronic parking system, the self-checking function of the EPB motor can be realized and the fault diagnosis can be carried out through scanning and sampling of the pins of the single chip microcomputer.

Description

Technical Field

[0001] The utility model relates to the technical field of automobile electronic control, in particular to a DC motor self-test circuit for an electronic parking system. Background Art

[0002] With the continuous advancement of automotive technology, electronic parking brakes (EPBs) have gradually replaced traditional mechanical parking brakes, becoming standard equipment in modern vehicles due to their significant advantages such as ease of operation and reliable performance. However, if the EPB motor does not have a self-diagnosis function, a motor failure will cause the motor to malfunction during parking, potentially leading to serious safety hazards such as vehicle coasting.

[0003] To solve the above problems, some electronic parking systems equipped with motor self-test circuits have appeared on the market. For example, CN117681846A discloses an electronic parking control system for electric vehicles, including: an EPB module, a vehicle main controller, a peripheral control circuit, a right parking motor and a left parking motor. After the vehicle is started, a self-test is performed. If an abnormality is found during the self-test, the vehicle cannot run and cannot be towed. The trailer button on the EPB module is turned to the towing position, the EPB module releases the electronic parking, and the vehicle can be towed normally. The EPB module also sends a signal to the vehicle main controller, and the vehicle main controller can no longer drive the vehicle to run. The vehicle is towed to a maintenance center for repair. After the repair is successful, the gear position of the EPB module is turned to the running gear, and the vehicle is restarted. At this time, the vehicle can execute the operating logic when the self-test is normal.

[0004] It can be seen that most existing self-test circuits can only perform simple self-test operations and lack comprehensive fault diagnosis capabilities. This requires maintenance personnel to spend more time and energy on troubleshooting when facing these problems, increasing the difficulty of automobile maintenance work, seriously affecting maintenance efficiency and quality, and also causing many inconveniences to car owners. Utility Model Content

[0005] The purpose of the utility model is to provide a DC motor self-test circuit for an electronic parking system to solve the above technical problems.

[0006] To achieve the above-mentioned objectives, the present invention provides a DC motor self-test circuit for an electronic parking system, comprising a positive terminal sampling circuit ADH, a negative terminal sampling circuit ADL connected to both ends of the EPB motor, and a self-test circuit connected to the negative terminal sampling circuit ADL, the self-test circuit comprising an NPN transistor Q1 and a PNP transistor Q2, the base of the NPN transistor Q1 being connected to a single-chip microcomputer for outputting a PWM wave, the emitter of the NPN transistor Q1 being grounded, the collector of the NPN transistor Q1 being connected to the base of the PNP transistor Q2, the collector of the PNP transistor Q2 being connected to a power supply terminal Vin, the emitter of the PNP transistor Q2 being connected to the negative terminal sampling circuit ADL, and the positive terminal sampling circuit ADH and the negative terminal sampling circuit ADL being both connected to the single-chip microcomputer.

[0007] Preferably, an anti-backflow diode Q3 is further connected in series between the emitter of the PNP transistor Q2 and the negative end sampling loop ADL, wherein the anti-backflow diode Q3 is unidirectionally conductive in the direction of the negative end sampling loop ADL.

[0008] Preferably, a voltage divider circuit is connected to both the positive end sampling circuit ADH and the negative end sampling circuit ADL, and the voltage divider circuit includes a first-stage voltage divider resistor connected between the anti-backflow diode Q3 and the negative end sampling circuit ADL, a second-stage voltage divider resistor connected in series to the negative end sampling circuit ADL or the positive end sampling circuit ADH, and a third-stage voltage divider resistor with one end connected to the negative end sampling circuit ADL or the positive end sampling circuit ADH, and the other end of the third-stage voltage divider resistor is grounded.

[0009] Preferably, both the positive end sampling loop ADH and the negative end sampling loop ADL are connected to a filter loop, and the filter loop includes a capacitor with one end connected to the positive end sampling loop ADH or the negative end sampling loop ADL, and the other end of the capacitor is grounded.

[0010] Preferably, current-limiting resistors are connected in series to both the positive terminal sampling loop ADH and the negative terminal sampling loop ADL.

[0011] Therefore, the present invention adopts the above-mentioned DC motor self-test circuit for the electronic parking system, which has the following beneficial effects:

[0012] 1. By monitoring the working status of the motor in real time, it can not only perform basic self-test operations, but also has comprehensive fault diagnosis functions and timely alarm when abnormalities are detected, which can greatly reduce the probability of faults;

[0013] 2. It can provide detailed fault information to help maintenance personnel quickly locate problems, improve maintenance efficiency, and ensure the safety and reliability of vehicles.

[0014] 3. It can be realized by only using transistors, diodes and resistors and capacitors. The circuit is simple, low cost and powerful.

[0015] In summary, the safety of the electronic parking system has been significantly improved, bringing a more reliable user experience to car owners and maintenance personnel.

[0016] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The utility model is a wiring schematic diagram of a DC motor self-test circuit for an electronic parking system. DETAILED DESCRIPTION

[0018] In the description of the present utility model, it should be noted that the terms "upper", "lower", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships in which the utility model product is usually placed when in use. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In the description of the present utility model, it should also be noted that, unless otherwise clearly specified and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be a communication between the internal parts of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0019] The following describes the embodiments of the present invention in detail with reference to the accompanying drawings.

[0020] like Figure 1 As shown, a DC motor self-test circuit for an electronic parking system includes a positive terminal sampling circuit ADH and a negative terminal sampling circuit ADL connected to both ends of the EPB motor, and a self-test circuit connected to the negative terminal sampling circuit ADL. The self-test circuit includes an NPN transistor Q1 and a PNP transistor Q2. The base of the NPN transistor Q1 is connected to a single-chip microcomputer for outputting a PWM wave, the emitter of the NPN transistor Q1 is grounded, the collector of the NPN transistor Q1 is connected to the base of the PNP transistor Q2, the collector of the PNP transistor Q2 is connected to the power supply terminal Vin, the emitter of the PNP transistor Q2 is connected to the negative terminal sampling circuit ADL, and the positive terminal sampling circuit ADH and the negative terminal sampling circuit ADL are both connected to the single-chip microcomputer.

[0021] An anti-backflow diode Q3 is also connected in series between the emitter of the PNP transistor Q2 and the negative end sampling loop ADL, wherein the anti-backflow diode Q3 is unidirectionally conducted in the direction of the negative end sampling loop ADL, wherein the anti-backflow diode Q3 is used to prevent current backflow, and the current limiting resistor R1 is used to prevent excessive current in the event of a short circuit.

[0022] A voltage divider circuit is connected to both the positive end sampling circuit ADH and the negative end sampling circuit ADL. The voltage divider circuit includes a first-stage voltage divider resistor R1 connected between the anti-backflow diode Q3 and the negative end sampling circuit ADL, a second-stage voltage divider resistor R2 or R5 connected in series to the negative end sampling circuit ADL or the positive end sampling circuit ADH, and a third-stage voltage divider resistor R3 or R6 with one end connected to the negative end sampling circuit ADL or the positive end sampling circuit ADH. The other end of the third-stage voltage divider resistor R3 or R6 is grounded.

[0023] The positive end sampling loop ADH and the negative end sampling loop ADL are both connected to a filter loop, which includes a capacitor C1 or C2 with one end connected to the positive end sampling loop ADH or the negative end sampling loop ADL, and the other end of the capacitor C1 or C2 is grounded.

[0024] The positive end sampling circuit ADH and the negative end sampling circuit ADL are both connected in series with a current limiting resistor R4 or R7.

[0025] Working principle: During normal operation, the MCU IO port outputs a PWM wave to control the switch of the NPN transistor Q1. When the output is high, the NPN transistor Q1 is turned on, which in turn drives the PNP transistor Q2 to turn on. At this time, the power supply terminal Vin passes through the anti-backflow diode Q3 and the current limiting resistor R1 to the negative end sampling circuit ADL, and the MCU detects the voltage value;

[0026] When the EPB motor is short-circuited to the power supply, the voltage at both ends of the EPB motor increases to the power supply voltage, causing the voltage at both ends of the positive end sampling circuit ADH and the negative end sampling circuit ADL to increase to the power supply voltage. At this time, the voltage acquisition value is greater than the threshold (the voltage value during normal operation is set as the threshold), and the EPB motor short-circuit fault to the power supply can be determined and output;

[0027] When the EPB motor is short-circuited to the ground, both ends of the EPB motor are grounded, and the collected values ​​at both ends of the positive end sampling circuit ADH and the negative end sampling circuit ADL are 0, the EPB motor short-circuit fault can be determined and output;

[0028] When the external wiring harness is supplying voltage, the EPB motor is equivalent to an external power supply. At this time, even if the microcontroller outputs a low level, the voltage value can still be collected, and the collected voltage value is higher than the set threshold, and the external wiring harness voltage supply fault can be determined and output.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A DC motor self-test circuit for an electronic parking system, characterized by: It includes a positive terminal sampling circuit ADH, a negative terminal sampling circuit ADL connected to both ends of the EPB motor, and a self-test circuit connected to the negative terminal sampling circuit ADL. The self-test circuit includes an NPN transistor Q1 and a PNP transistor Q2. The base of the NPN transistor Q1 is connected to a single-chip microcomputer for outputting a PWM wave, the emitter of the NPN transistor Q1 is grounded, the collector of the NPN transistor Q1 is connected to the base of the PNP transistor Q2, the collector of the PNP transistor Q2 is connected to the power supply terminal Vin, the emitter of the PNP transistor Q2 is connected to the negative terminal sampling circuit ADL, and the positive terminal sampling circuit ADH and the negative terminal sampling circuit ADL are both connected to the single-chip microcomputer.

2. The DC motor self-test circuit for an electronic parking system according to claim 1, characterized in that: An anti-backflow diode Q3 is further connected in series between the emitter of the PNP transistor Q2 and the negative end sampling loop ADL, wherein the anti-backflow diode Q3 is unidirectionally conductive in the direction of the negative end sampling loop ADL.

3. The DC motor self-test circuit for an electronic parking system according to claim 2, characterized in that: A voltage divider circuit is connected to both the positive end sampling circuit ADH and the negative end sampling circuit ADL. The voltage divider circuit includes a first-stage voltage divider resistor connected between the anti-backflow diode Q3 and the negative end sampling circuit ADL, a second-stage voltage divider resistor connected in series to the negative end sampling circuit ADL or the positive end sampling circuit ADH, and a third-stage voltage divider resistor with one end connected to the negative end sampling circuit ADL or the positive end sampling circuit ADH. The other end of the three-stage voltage divider resistor is grounded.

4. The DC motor self-test circuit for an electronic parking system according to claim 3, characterized in that: The positive end sampling loop ADH and the negative end sampling loop ADL are both connected to a filter loop. The filter loop includes a capacitor with one end connected to the positive end sampling loop ADH or the negative end sampling loop ADL, and the other end of the capacitor is grounded.

5. The DC motor self-test circuit for an electronic parking system according to claim 4, characterized in that: Current limiting resistors are connected in series to both the positive end sampling loop ADH and the negative end sampling loop ADL.

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