A parking system wake-up device and judgment method

Abstract

The present invention relates to parking brake technology and discloses a parking system wake-up device and judgment method. The device comprises an EPB main controller and a vehicle power supply. The device is characterized by also including an EPB switch with a parking wake-up function. The vehicle power supply provides a battery power supply (BAT) and an ignition power supply (IGN) to the EPB main controller. The EPB switch is connected to the battery power supply (BAT) and the ignition power supply (IGN). The present invention includes a power wake-up module. When in quiescent state, the power chip is inoperative, resulting in zero quiescent current, which helps protect the power supply. The system designed by the present invention also has higher safety performance.

Description

Technical Field

[0001] The present invention relates to a parking brake technology, and in particular to a parking system awakening device and a judgment method. Background Art

[0002] Article 4.2.1.25.E of GB12676-2014 "Technical Requirements and Test Methods for Braking Systems of Commercial Vehicles and Trailers" stipulates: After turning off the ignition / start switch that controls the power of the braking equipment and / or removing the key, the parking brake can still be engaged, but the brake cannot be released.

[0003] For example, the prior art CN201920173924.X discloses a control switch circuit for an automotive electronic parking system EPB. After the power is cut off, the EPB switch can be awakened and the brakes can still be released, which does not meet the above requirements. When the vehicle is stopped and the ignition power is turned off, the EPB system is generally in sleep mode or power-off mode. During this period, the EPB system electronic control unit (ECU for short) will reduce its own power consumption to a minimum. Generally, the total current does not exceed 1 mA, and the current in sleep mode or power-off mode is called static current. Although the static current is very small, for vehicles that are parked for a long time, long-term leakage current will cause serious power supply to the car battery, affecting the vehicle start-up, and even damage the car battery.

[0004] For example, CN201811482322.9 in the existing technology can meet certain voltage resistance requirements and ensure ultra-low power consumption. At the same time, it integrates multiple high-side switches, has CAN communication function, SPI communication function, watchdog function, and can output 5V and 3.3V. There are fewer types of power supply chips and the price is higher.

[0005] In static mode, although the power chip and EPB switch are working periodically and the ASIC chip enters the lowest power consumption mode, its life and performance will still be affected, which will shorten its service life and have a greater impact on system security.

[0006] The ECU will wake up and exit sleep mode before entering normal operating mode. This indicates that even after turning off the ignition / start switch (which controls the braking system's power) and / or removing the key, the parking brake can still be engaged and released, which is inconsistent with GB12676-2014. The system's parking button, release button, and AUTOHOLD mode button all have the ability to wake the system, meaning pressing any button will cause the system to exit sleep mode. This makes it easy for the system to exit sleep mode by mistake, resulting in unnecessary work and current consumption. When the vehicle is turned off and the ignition signal drops to 0, the system automatically determines the vehicle's status, automatically executes the parking command, locks the wheels, and shortly thereafter enters sleep mode. This indicates that the vehicle automatically enters the parking state after the power is lost. Summary of the Invention

[0007] The present invention addresses the problem that although the power chip and EPB switch are periodically working and the ASIC chip enters the lowest power consumption mode, the power supply life and performance are still affected, which has a significant impact on system security. A parking system wake-up device and judgment method are provided.

[0008] In order to solve the above technical problems, the present invention is solved by the following technical solutions:

[0009] A parking system wake-up device includes an EPB main controller and a vehicle power supply; the device also includes an EPB switch with a parking wake-up function; the vehicle power supply provides a battery power BAT and an ignition power IGN to the EPB main controller; and the EPB switch is connected to the battery power BAT and the ignition power IGN.

[0010] Preferably, the EPB switch includes an EPB switch MCU unit and a switching power supply module, the parking wake-up end of the switching power supply module is connected to the EPB parking wake-up switch S3, the other end of the EPB parking wake-up switch S3 is connected to the battery power BAT end of the switching power supply module, and the PWR_Ctl of the EPB switch MCU unit is connected to the PWR_Ctl end of the switching power supply module, so that the switching power supply module maintains the power output state.

[0011] Preferably, the EPB main controller includes a main power module, a main controller MCU, and a CAN bus with a CAN wake-up function; the main power module receives the battery power BAT and the ignition power IGN, and converts the received power and transmits it to the main controller MCU; the CAN bus with a CAN wake-up function is connected to the CAN bus of the EPB switch.

[0012] Preferably, the main power supply module includes a main power supply chip U2, and the power output terminal VDD of the main power supply chip U2 is connected to the MCU terminal of the main controller; the power input terminal of the main power supply chip U2 is connected to a diode D1, and the other end of the diode D1 is connected to the battery power supply BAT terminal; the enable terminal High_level_en of the main power supply chip U2 is connected to a MOS tube Q1, the S end of the MOS tube Q1 is connected to the diode D1 and the resistor R1, and the G end of the MOS tube Q1 is connected to the resistor R1 and the resistor R2; the other end of the resistor R2 is connected to the transistor T2, the emitter of the transistor T2 is connected to the resistor R4, the resistor R3, the resistor R5, and the resistor R9, the other end of the resistor R9 is connected to the diode D8, the other end of the resistor R3 is connected to the diode D6, the other end of the resistor R5 is connected to the diode D7, and the other end of the resistor R4 is grounded.

[0013] Preferably, the switching power supply module includes a switching power supply chip U1, the BAT end of the switching power supply chip is connected to a diode D11, the high_level_en end is connected to a resistor R19, a resistor R14 and a diode D18, the resistor R19 and the diode D18 are connected in series, and the other end of the diode D18 is connected to the EPB parking wake-up switch S3.

[0014] Preferably, the switching power supply module further includes diodes D13, D15, D16, and a resistor R13; the diode D16, the resistor R13, the diode D13, and the diode D15 are connected in series in sequence, the other end of the diode D16 is connected to the PWR_Ctl terminal of the switch MCU, the other end of the diode D13 is connected to the resistor R16, the other end of the resistor R16 is connected to the resistor R17 and the resistor R18, the other end of the resistor R18 is connected to the capacitor C17, and the other ends of the capacitor C17 and the resistor R17 are both grounded.

[0015] In order to solve the above technical problems, the present invention further provides a parking system wake-up determination method, which includes any of the parking system wake-up devices described above, and the method includes:

[0016] The parking system switch voltage is determined by setting the PWR_Ctl terminal output of the switch MCU to a high level, thereby determining the parking system switch voltage;

[0017] The ignition power supply voltage VHCU is determined by collecting the AD terminal voltage of the switching power supply module in the EPB switch unit to determine the ignition power supply voltage VHCU;

[0018] The parking system power-off mode is determined by comparing the ignition power supply voltage VHCU with the set power-on threshold;

[0019] The parking wake-up power-on mode is determined by comparing the voltage Vh of the sensor in the EPB switch unit with the threshold Vha to determine that it is the parking wake-up power-on mode.

[0020] As a preferred method, the ignition power supply voltage VHCU is determined by sampling the AD value of the AD1 port to obtain the voltage Vad1 of the AD1 port. Assuming that the voltage drop of D15 is U D15 , then the ignition voltage VHCU=Vad1*(R16+R17) / R17+U D15 .

[0021] Preferably, the parking system power-off mode is determined by setting the ignition power-on voltage threshold V12 and the ignition power-off voltage threshold V11. When the ignition power supply voltage VHCU is greater than the ignition power-on voltage threshold V12, it is in the ignition power-on mode. Otherwise, the ignition power supply voltage VHCU is compared with the ignition power-off voltage threshold V11. When the ignition power supply voltage VHCU is less than the ignition power-off voltage threshold V11, it is in the ignition power-off mode.

[0022] Preferably, the voltage Vh of the sensor in the EPB switch unit is obtained through the output curve of the EPB switch handle angle change.

[0023] The present invention has significant technical effects due to the adoption of the above technical solutions:

[0024] The power chip used in the present invention is the most common power chip with a single function, a wide variety of types on the market, and a low price; thus, the cost of the entire parking system is low;

[0025] When the present invention is in static state, the single chip microcomputer, the power supply chip and the like do not work, the static current is zero, and the safety is higher.

[0026] The present invention complies with the GB 12676-2014 standard. Even if a child is in a keyless car and the car is parked on a slope, the car will not slide down the slope after being triggered by mistake, thus avoiding danger. At the same time, the brake cannot be easily released and the car cannot be towed away without a key.

[0027] In the EPB switch of the present invention, the EPB parking wake-up switch S3 will be turned on only when the EPB switch handle position of the EPB switch is pulled down to 24.5 degrees, thereby waking up the system, reducing false triggering, and thus unnecessary work and current consumption.

[0028] At the same time, after the power is cut off, the system of the present invention will put it in the parking position. There are two ways to put the system in the release position after the power is cut off, which is convenient for towing. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a block diagram of the EPB switch of the present invention;

[0030] Figure 2 is a block diagram of the parking system of the present invention;

[0031] Figure 3 This is the EPB switch module power wake-up circuit diagram of the present invention;

[0032] Figure 4 This is a power awakening circuit diagram of the EPB main controller module of the present invention;

[0033] Figure 5 This is an output curve diagram of the EPB switch handle angle change of the present invention;

[0034] Figure 6 This is a flow chart of the power-on mode judgment of the EPB switch module system of the present invention. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0036] Example 1

[0037] Figure 1 As shown, the vehicle power supply provides dual power supplies to the EPB switch, one of which is the battery power BAT and the other is the vehicle ignition power IGN.

[0038] After turning off the ignition / start switch that controls the power energy of the brake equipment and / or removing the key, BAT still has power but IGN has no power; by operating the EPB switch to enable parking wake-up, the switching power supply module of the EPB switch is awakened. The switching power supply module of the EPB switch converts the voltage of BAT into a 5V power supply. After the switch MCU is powered on, it starts working. The PWR_Ctl output of the switch MCU is high to keep the switching power supply module of the EPB switch in the power output state; even if the parking wake-up is invalid after releasing the EPB switch, the switch MCU can still work normally; the EPB switch works normally after being powered on.

[0039] The switching power supply module switching power supply chip U1 of the EPB switch is a high-level enable chip, and BAT is the vehicle battery power supply. When the vehicle battery power supply is normally supplied, the ignition power supply IGN or the EPB parking wake-up switch can be used to make the high-level enable port High_level_en of U1 obtain a high level, thereby converting the vehicle battery power supply into a 5V power supply, and the switch MCU works normally.

[0040] like Figure 3 In the diagram, diodes D11, D18, and D15 prevent reverse power connection. When the ignition power supply (IGN) is disconnected, diodes D13 and D15 prevent the EPB parking wake-up switch S3 from switching on and then diverting the battery power to the IGN network, misleading the EPB main controller into believing normal power is on. D13 prevents the battery power or the power output from the switch MCU from interfering with the MCU's assessment of the system power status. Diode D16 prevents cross-current from the ignition power or battery power supply to the MCU ports, potentially damaging the switch MCU. The MCU's control port withstand voltage is lower than that of the ignition power and battery power supplies, preventing high voltage from directly acting on the MCU's control port.

[0041] In this embodiment, when D13 is replaced with a wire and the parking wake-up switch S3 is turned on, the battery power supply BAT voltage is divided by D18, R19, R16, and R17, and then applied to the switch MCU's AD acquisition port AD1 through the current-limiting resistor R18. Similarly, when the switch MCU's control port "PWR_Ctl" outputs a high level, a voltage is also applied to the switch MCU's AD acquisition port AD1. Both situations can affect the determination of whether the ignition power supply is powered. With the addition of D13, D13's reverse blocking function prevents its voltage from affecting the determination of whether the ignition power supply is powered.

[0042] The switch MCU can obtain the voltage Vad1 of the AD1 port by collecting the AD value of the AD1 port; assuming that the voltage drop of D15 is 0.7V, the ignition voltage VHCU = Vad1*(R16+R17) / R17+0.7.

[0043] The withstand voltage of the MCU's control port is lower than that of the ignition power supply and battery power supply, which prevents high voltage from directly acting on the MCU's control port.

[0044] The output voltage Vh of the Hall sensor changes with the angle of the EPB switch handle. When the EPB switch handle is at the 0° zero position, that is, it is not moving, the voltage at the zero point is calibrated as Vhb; when the EPB switch handle is at the 20° ignition point misoperation judgment position, the voltage is set as Vha, such as Figure 5 .

[0045] The switching power supply module includes a switching power supply chip U1. The BAT end of the switching power supply chip is connected to a diode D11. The high_level_en end is connected to a resistor R19, a resistor R14 and a diode D18. The resistor R19 and the diode D18 are connected in series. The other end of the diode D18 is connected to the EPB parking wake-up switch S3.

[0046] The switching power supply module also includes diodes D13, D15, D16, and resistor R13. Diode D16, resistor R13, diode D13, and diode D15 are connected in series. The other end of diode D16 is connected to the Pwr_ctl terminal of the switching MCU. The other end of diode D13 is connected to resistor R16, which is connected to resistors R17 and R18. The other end of resistor R18 is connected to capacitor C17. The other ends of capacitor C17 and resistor R17 are both grounded. Switching power supply chip U1 is a high-level power enable chip.

[0047] The resistors R16 and R17 are designed to ensure that the voltage on the AD acquisition port AD1 of the MCU within the effective input range of the ignition power supply IGN does not exceed the operating voltage of the MCU, and a certain margin is left.

[0048] Resistors R16 and R17 are designed to ensure that the voltage on the MCU's AD acquisition port AD1 does not exceed the MCU's operating voltage within the effective input range of the ignition power supply IGN, with a certain margin. R18 is a current-limiting resistor. The MCU calculates the ignition power supply voltage based on the voltage on AD1 and determines whether the system is in ignition power-on mode, ignition power-off mode, or other fault mode.

[0049] Assuming that the EPB system is a 24V system, the general power supply voltage range is 18V to 32V. When the voltage obtained by voltage division on R17 is greater than or equal to 5V, the switch MCU uniformly recognizes it as 5V. Leaving a certain margin means that when the voltage is 32V, the voltage obtained by voltage division on R17 is slightly less than 5V, such as 4.5V.

[0050] Example 2

[0051] Based on Example 1, this embodiment is an electronic parking brake system with a parking wake-up function, including an EPB main controller and a vehicle power supply; it also includes an EPB switch with a parking wake-up function; the vehicle power supply provides battery power BAT and ignition power IGN to the EPB main controller; the EPB switch is connected to the battery power BAT and the ignition power IGN.

[0052] The EPB main controller includes a main power module, a main controller MCU, and a CAN bus with a CAN wake-up function; the main power module receives the battery power BAT and the ignition power IGN, and converts the received power and transmits it to the main controller MCU; the CAN bus with a CAN wake-up function is connected to the CAN bus of the EPB switch.

[0053] The main power supply module includes a main power supply chip U2, and the power output terminal VDD of the main power supply chip U2 is connected to the MCU terminal of the main controller; the power input terminal of the main power supply chip U2 is connected to a diode D1, and the other end of the diode D1 is connected to the battery power supply BAT terminal; the enable terminal High_level_en of the main power supply chip U2 is connected to a MOSFET Q1, the S end of the MOSFET Q1 is connected to the diode D1 and the resistor R1, and the G end of the MOSFET Q1 is connected to the resistors R1 and R2; the other end of the resistor R2 is connected to the transistor T2, and the emitter of the transistor T2 is connected to the resistors R4, R3, R5, and R9, the other end of the resistor R9 is connected to the diode D8, the other end of the resistor R3 is connected to the diode D6, the other end of the resistor R5 is connected to the diode D7, and the other end of the resistor R4 is grounded.

[0054] The main power module includes diodes D1, D6, D7, D8, resistors R1, R2, R3, R4, R5, R9, NPN transistor T2, P-channel MOS tube Q1, and main power chip U2.

[0055] Diode D1 is used to prevent reverse power connection. The maximum voltage difference between the S-level and G-level of the P-channel MOS transistor Q1 is VGSmax. When the ignition power supply IGN is powered on, or the PWR_Hold port of the MCU outputs a high level, or the CAN wake-up signal is valid (outputs a high level), the collector and emitter of T2 are turned on;

[0056] The voltage divider network composed of D1, R1, R2, D8, and T2 needs to ensure that when the vehicle power reaches its maximum value, the voltage VR1 divided by R1 is less than VGSmax, thereby ensuring that the P-channel MOS tube Q1 will not break down due to overvoltage.

[0057] Resistors R3 and R4 are designed to ensure that the collector and emitter of T2 are effectively turned on when the MCU's PWR_Hold port outputs a high level. Resistors R5 and R4 are designed to ensure that the collector and emitter of T2 are effectively turned on within the effective input range of the ignition power supply IGN. Resistors R9 and R4 are designed to ensure that the collector and emitter of T2 are effectively turned on when the AN wake-up signal is valid.

[0058] Diode D6 is used to prevent the ignition power supply IGN from being connected to the MCU port and burning the MCU; diode D7 is used to prevent the power supply from being connected reversely. At the same time, when the ignition power supply IGN is powered off, it prevents the high level output by the MCU's PWR_Hold port from being connected to the ignition power supply IGN and affecting other ECUs connected to the ignition power supply IGN and causing them to mistakenly judge that the power is not turned off.

[0059] Diode D8 is used to prevent the ignition power supply IGN from being connected to the CAN wake-up port and thus burning the internal CAN bus with CAN wake-up function;

[0060] When the ignition power supply IGN is powered on or the CAN wake-up port outputs a high level or the PWR_Hold port outputs a high level, the collector and emitter of T2 are turned on, and then the S-stage and D-stage of the P-channel MOS tube Q1 are turned on, thereby enabling the main power chip U2. The main power chip outputs +5V, and the main MCU works normally.

[0061] Example 3

[0062] Based on the above embodiment, this embodiment is a judgment method with parking wake-up function, through the process Figure 6 It can be seen that the EPB switch sends the system power status to the EPB main controller through the switch CAN bus.

[0063] The switch MCU calculates the ignition power supply voltage VHCU through the voltage on AD1, and then combines it with the output voltage Vh of the Hall sensor to determine the system power status. The power status includes ignition power-on mode, parking wake-up power-on or complete power-off.

[0064] Assuming the EPB system is a 24V system with a general power supply voltage range of 18V to 32V, a voltage V12 slightly lower than the minimum power supply voltage is set as the ignition power-on threshold, for example, V12 = 17V. When the ignition power is lost, the theoretically collected ignition voltage is 0V. A voltage V12 slightly higher than the minimum 0V is set as the ignition power-off threshold, for example, V11 = 0.5V. VHCU is used to determine whether the ignition is powered on or off. If VHCU is greater than the set threshold V12, it is determined to be ignition powered on; if VHCU is less than the set threshold V11, it is determined to be ignition powered off. After the ignition is determined to be powered off, if the output voltage Vh of the Hall sensor is greater than the set threshold Vha, it is determined to be in the parking wake-up power-on state. If the output voltage Vh of the Hall sensor is between the set threshold Vhb ± 0.2V, it is determined to be completely powered off.

Claims

1. A parking system wake-up device, including an EPB main controller and a vehicle power supply; characterized in that: It also includes an EPB switch with a parking wake-up function; the vehicle power supply provides battery power BAT and ignition power IGN to the EPB main controller; the EPB switch is connected to the battery power BAT and ignition power IGN; The EPB switch includes an EPB switch MCU unit, a switching power module, and a Hall sensor. The parking wake-up terminal of the switching power module is connected to the EPB parking wake-up switch S3. The other end of the EPB parking wake-up switch S3 is connected to the battery power BAT terminal of the switching power module. The PWR_Ctl of the EPB switch MCU unit is connected to the PWR_Ctl terminal of the switching power module, so that the switching power module maintains the power output state. The output voltage Vh of the Hall sensor changes with the angle of the EPB switch handle; The switching power supply module includes a switching power supply chip U1, the BAT terminal of the switching power supply chip is connected to a diode D11, the high_level_en terminal is connected to a resistor R19, a resistor R14 and a diode D18, the resistor R19 and the diode D18 are connected in series, and the other end of the diode D18 is connected to the EPB parking wake-up switch S3; the switching power supply module also includes diodes D13, D15, D16, and a resistor R13; the diode D16, the resistor R13, the diode D13, and the diode D15 are connected in series in sequence, the other end of the diode D16 is connected to the PWR_Ctl terminal of the switch MCU, the other end of the diode D13 is connected to the resistor R16, the other end of the resistor R16 is connected to the resistor R17 and the resistor R18, the other end of the resistor R18 is connected to the capacitor C17, and the other ends of the capacitor C17 and the resistor R17 are both grounded.

2. The parking system wake-up device according to claim 1, characterized in that: The EPB main controller includes a main power module, a main controller MCU, and a CAN bus with a CAN wake-up function; the main power module receives the battery power BAT and the ignition power IGN, and converts the received power and transmits it to the main controller MCU; the CAN bus with a CAN wake-up function is connected to the CAN bus of the EPB switch.

3. The parking system wake-up device according to claim 2, characterized in that: The main power supply module includes a main power supply chip U2, and the power output terminal VDD of the main power supply chip U2 is connected to the MCU terminal of the main controller; the power input terminal of the main power supply chip U2 is connected to a diode D1, and the other end of the diode D1 is connected to the battery power supply BAT terminal; the enable terminal High_level_en of the main power supply chip U2 is connected to a MOSFET Q1, the S end of the MOSFET Q1 is connected to the diode D1 and the resistor R1, and the G end of the MOSFET Q1 is connected to the resistors R1 and R2; the other end of the resistor R2 is connected to the transistor T2, the emitter of the transistor T2 is connected to the resistors R4, R3, R5, and R9, the other end of the resistor R9 is connected to the diode D8, the other end of the resistor R3 is connected to the diode D6, the other end of the resistor R5 is connected to the diode D7, and the other end of the resistor R4 is grounded.

4. A parking system wake-up judgment method, characterized in that: The parking system wake-up device according to any one of claims 1 to 3, wherein the method comprises: The parking system switch voltage is determined by setting the PWR_Ctl terminal output of the switch MCU to a high level, thereby determining the parking system switch voltage; The ignition power supply voltage VHCU is determined by collecting the AD terminal voltage of the switching power supply module in the EPB switch unit to determine the ignition power supply voltage VHCU; The parking system power-off mode is determined by comparing the ignition power supply voltage VHCU with the set power-on threshold; The parking wake-up power-on mode is determined by comparing the voltage Vh of the sensor in the EPB switch unit with the threshold Vha to determine that it is the parking wake-up power-on mode.

5. The parking system wake-up determination method according to claim 4, characterized in that: To determine the ignition power supply voltage VHCU, the switch MCU obtains the voltage Vad1 of the AD1 port by collecting the AD value of the AD1 port. Assuming that the voltage drop of D15 is U D15 , then the ignition voltage VHCU=Vad1*(R16+R17) / R17+ U D15 .

6. The parking system wake-up determination method according to claim 4, characterized in that: To determine the parking system power-off mode, set the ignition power-on voltage threshold V12 and the ignition power-off voltage threshold V11. When the ignition power supply voltage VHCU is greater than the ignition power-on voltage threshold V12, the ignition power-on mode is selected. Otherwise, the ignition power supply voltage VHCU is compared with the ignition power-off voltage threshold V11. When the ignition power supply voltage VHCU is less than the ignition power-off voltage threshold V11, the ignition power-off mode is selected.

7. The parking system wake-up determination method according to claim 4, characterized in that: The voltage Vh of the sensor in the EPB switch unit is obtained through the output curve of the EPB switch handle angle change.

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