Standby power supply system for vehicle door lock

Abstract

The invention belongs to the technical field of automobile door locks, and discloses a vehicle door lock standby power supply system which comprises a door lock unit and a standby power supply, the standby power supply is connected with the door lock unit through a control unit, the control unit judges whether a vehicle collides according to pulse width changes of collision signals, and if the pulse width changes, the standby power supply is started. If yes, it is judged that the vehicle collides, then preset time is delayed, then the standby power supply is controlled to supply power to the door lock unit, and unlocking is achieved; and if the pulse width does not change, judging that the vehicle is not collided, and not performing subsequent processing. According to the method, more serious damage caused by the fact that a vehicle door is opened due to the fact that people touch the vehicle by mistake during rolling of the vehicle can be reduced, guarantee can be provided for safe unlocking of the vehicle door under the crisis situation, smooth implementation of follow-up rescue is guaranteed, and meanwhile whether the vehicle is collided or not is judged according to pulse width changes of collision signals. The vehicle-mounted collision signal self-change rule is better met, the practicability is higher, and the application range is wider.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile door locks, and in particular relates to a vehicle door lock backup power supply system. Background Art

[0002] At present, most cars still use the traditional low-voltage power supply network, with a single power supply supplying power to the load. During driving, once a vehicle collides, the entire vehicle may lose power, and the door lock control unit will not have enough energy to unlock the door, which will cause the door lock to remain in a locked state, and rescuers will not be able to open the door, affecting safety. In reality, this phenomenon occurs from time to time. At the same time, unlocking the door after a collision is also one of the important certification items of the national standard collision test. In order to reduce the risk of the door not being able to be unlocked smoothly after a vehicle collision, a backup power supply can be used to power the door lock control unit. When the main power supply fails and cannot supply power, the backup power supply is used to unlock the door and successfully rescue the people in the car.

[0003] An existing patent with application number CN115912602A and name "A method for connecting a backup power supply with a single power input" discloses that the backup power supply automatically outputs energy for unlocking the vehicle doors during a collision, without considering whether the vehicle's state is suitable for unlocking at this time. For example, during a violent collision that causes the vehicle to roll over, if the door is unlocked successfully, the door may be opened due to accidental touch or system failure, thereby causing further risk of casualties to the people in the vehicle. At the same time, the backup power supply of this patent can only directly output energy when the load KL30 line is disconnected, and it cannot determine whether the vehicle is in a collision state at this time, and may cause over-capacity and erroneous energy output. Summary of the invention

[0004] The present invention provides a vehicle door lock backup power supply system, which solves the technical problem that the prior art outputs a door unlocking signal as long as the load line is disconnected. If the vehicle is in a rolling state at this time, it is easy to accidentally open the door, causing further casualties.

[0005] The present invention can be achieved through the following technical solutions:

[0006] A vehicle door lock backup power supply system comprises a door lock unit and a backup power supply, wherein the backup power supply is connected to the door lock unit via a control unit, and the control unit is used to judge whether a vehicle has collided according to a change in the pulse width of a collision signal, and if the pulse width changes, it is judged that the vehicle has collided, and then the backup power supply is controlled to supply power to the door lock unit after a predetermined delay to achieve unlocking;

[0007] If the pulse width does not change, it is determined that the vehicle has not collided and no subsequent processing is performed.

[0008] By utilizing the predetermined time of delay, it is possible to avoid using the backup power supply to power the door lock unit during an intense collision or at the beginning of a collision. This can not only reduce the risk of doors opening due to accidental touch by occupants during vehicle rollover, causing more serious injuries, but also provide protection for the safe unlocking of doors in crisis situations, ensuring the smooth implementation of subsequent rescue. At the same time, it can determine whether a vehicle has collided based on the pulse width change of the collision signal (of course, normal pulse fluctuations need to be ignored), which is more in line with the changing rules of the vehicle-mounted collision signal itself, is more practical, and has a wider range of applications.

[0009] Furthermore, the control unit includes a judgment module, a delay module and a discharge control switch.

[0010] The judgment module adopts a double-trigger monostable multivibrator structure to judge whether the pulse width of the collision signal changes; the delay module also adopts a double-trigger monostable multivibrator structure to delay for a first predetermined time after the pulse width of the collision signal changes, and output a door unlocking signal, while closing the discharge control switch to control the backup power supply to continuously supply power to the door lock unit for a second predetermined time to ensure unlocking.

[0011] A monostable multivibrator is an electronic circuit with a single stable state and a quasi-stable state. It can generate a delay of a predetermined time after receiving a trigger signal, and then automatically return to a stable state from the quasi-stable state. Its principle is to use positive feedback and an inverter to achieve that when the input signal exceeds a certain threshold, the output will flip and remain for a period of time, and then automatically return to its original state. Therefore, it has a wide range of applications in the fields of timers, delay devices, pulse generators, etc. The present invention uses a double-trigger monostable multivibrator to construct a judgment module that acts as a pulse generator to determine whether the pulse width of the collision signal changes, thereby determining whether a vehicle has collided, and then uses a double-trigger monostable multivibrator to construct a judgment module that acts as a delay device to ensure that the door unlocking signal is delayed output, and minimize the door opening due to accidental touch during the rolling period to reduce further damage. At the same time, the door lock unit is continuously powered during the door opening period to ensure that the door can be opened, and the door will not be unable to open due to lack of power supply during the operation of the door lock unit.

[0012] Further, the judgment module includes a first double-trigger monostable multivibrator, wherein the two oscillators are respectively recorded as oscillator I and oscillator II, and the delay module includes a second double-trigger monostable multivibrator, wherein the two oscillators are respectively recorded as oscillator III and oscillator IV.

[0013] Pin B of the oscillator I is connected to the output end of the collision signal, and its pin / Q and the collision signal output end are connected to pin / A of the oscillator II through respective diodes. The oscillator II is connected to pin B of the oscillator III, and pin Q of the oscillator III is connected to pin / A of the oscillator IV. Pin Q of the oscillator IV is connected to the discharge control switch.

[0014] Further, the pulse width of the output signal of the oscillator I is between the pulse width of the collision signal without collision and the pulse width of the collision signal with collision;

[0015] Since the output end of the collision signal and the pin / Q of the oscillator I are connected to the pin / A of the oscillator II through their own diodes, the two diodes together form an OR gate. As is known to all, the pin / A is triggered by a falling edge, and the pulse width of the output signal of the oscillator I is between the pulse width of the collision signal without collision and the pulse width of the collision signal with collision. When there is no collision, although the output of the collision signal and the pin / A changes between high level and low level, there will always be a high level at the same time, so the oscillator II will not be triggered; and when a collision occurs, a low level will be generated during a high level period of the normal output of the oscillator I, and at this time, the input signal of the pin / A of the oscillator II will have a falling edge, thereby triggering the oscillator II.

[0016] The pulse width of the output signal of the oscillator II is greater than the pulse width of the output signal of the oscillator III. The pulse width of the output signal of the oscillator III is set to a first predetermined time period to ensure that during the delay period of the door opening, the delay time will not be uncontrollable due to changes in the input signal of the oscillator III;

[0017] The pulse width of the output signal of the oscillator IV is set to the closing time of the discharge control switch, that is, the time period of the second predetermined time, to provide an action time for opening the door, that is, sufficient unlocking time.

[0018] Furthermore, the input end of the judgment module is connected to the output end of the collision signal, and the output end thereof is connected to the input end of the delay module. The output end of the delay module is connected to the discharge control switch, and the discharge control switch is connected between the backup power supply and the door lock unit.

[0019] Further, the discharge control switch includes a pair of back-to-back PMOS tubes, namely a first PMOS tube and a second PMOS tube, both of which have body diodes, the source of the first PMOS tube is connected to the backup power supply, the gate of the first PMOS tube is connected to the drain of the first NMOS tube, the source of the first NMOS tube is grounded, and the gate of the first NMOS tube is connected to the output end of the door unlocking signal;

[0020] The source of the second PMOS tube is connected to the door lock unit, and the gate thereof is connected to the drain of the second NMOS tube. The source of the second NMOS tube is grounded, and the gate thereof is connected to the output end of the first comparator. The negative end of the first comparator is connected to the main power supply, and the positive end is connected to the positive pole of the backup power supply.

[0021] Furthermore, the backup power supply is connected to the main power supply through a delayed cut-off module and a charging management module in sequence. The main power supply is also directly connected to a door lock unit. The delayed cut-off module is used to cut off the connection between the backup power supply and the main power supply during the delay period. The charging management module is used to control the main power supply to charge the backup power supply.

[0022] Furthermore, the delay cut-off module includes a second comparator and a third comparator connected in series, wherein the negative end of the second comparator is connected to the main power supply, the positive end thereof is connected to the positive electrode of the backup power supply, and the output end thereof is connected to the negative end of the third comparator, the positive end of the third comparator is connected to the reference voltage, and the output end thereof is connected to the gate of the third NMOS tube, the source of the third NMOS tube is grounded, and the drain thereof is connected to the gate of the third PMOS tube, and the third PMOS tube has a body diode, the source thereof is connected to the positive electrode of the backup power supply, and the drain thereof is connected to the charging management module. By comparing the voltages of the main power supply and the backup power supply, the delay cut-off module is triggered to operate, and the circuit through which the backup power supply supplies power to the door lock unit through the charging management module is cut off, thereby ensuring that the door lock unit will not be powered during the delay period, causing the door to be opened by mistake.

[0023] Furthermore, the main power supply is also connected to the door lock unit through an anti-backflow module, and the anti-backflow module is used to ensure that current can only flow from the main power supply to the door lock unit to prevent reverse flow.

[0024] The beneficial technical effects of the present invention are as follows:

[0025] 1. By detecting the pulse width change of the collision signal, it is determined whether the vehicle has collided, and then the door unlocking signal is output after a predetermined delay. This can not only reduce the risk of the door opening due to accidental touch by the occupants during the vehicle rollover, causing more serious injuries, but also provide protection for the safe unlocking of the door in a crisis situation, ensuring the smooth implementation of subsequent rescue. At the same time, judging whether the vehicle has collided based on the pulse width change of the collision signal is more in line with the change law of the vehicle-mounted collision signal itself, and is more practical and has a wider range of applications.

[0026] 2. A delayed cut-off module is added to the control unit. The delayed cut-off module is set between the charging management module and the backup power supply. The dual-pass comparator is used to compare the voltages of the backup power supply Upack and the main power supply KL30, and the shutdown and conduction of the third PMOS tube are controlled according to the comparison result. Once a collision occurs, the voltage comparison result changes, driving the shutdown of the third PMOS tube to ensure that the backup power supply will not discharge the load Load_KL30 through the charging management module during the delay period, thereby improving safety.

[0027] 3. Two double-trigger monostable multivibrators are used to construct a judgment module and a delay module, wherein oscillator I is used to detect pulse width changes, and the output signal of oscillator I and the collision signal are processed through an OR gate and then input into oscillator II, and then the pulse width of the pulse signal output by oscillator II is controlled by an RC circuit to make it greater than the output pulse width of oscillator III, i.e., the first predetermined time, to ensure that the input signal of oscillator III does not change during the delay period, and finally the second predetermined time, i.e., the discharge time, is limited by the output pulse width of oscillator IV to make it greater than the action time of the door lock unit, to ensure that the door can be opened, and at the same time, since the input pin / A of oscillator IV is a falling edge trigger, as long as the first predetermined time is reached, the output of oscillator III will produce a falling edge, and oscillator IV will be triggered, thereby ensuring the smooth execution of the second predetermined time, and the entire structure very cleverly realizes the detection of collision signals, the limitation of delay time and discharge time, and the circuit structure is simple and convenient to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is the overall circuit structure block diagram of the present invention;

[0029] Figure 2 It is a schematic diagram of the circuit structure of the anti-backflow module of the present invention;

[0030] Figure 3 Schematic diagram of the circuit structure of the charging management module of the present invention;

[0031] Figure 3 Schematic diagram of the circuit structure of the charging management module of the present invention;

[0032] Figure 4 Schematic diagram of the circuit structure of the discharge control module of the present invention;

[0033] Figure 5 It is a block diagram of the overall circuit structure of the delay control of the present invention;

[0034] Figure 6 It is a schematic diagram of the circuit structure of the delay control module of the present invention;

[0035] Figure 7 Schematic diagram of the output waveform of oscillator I in the judgment module of the present invention when no collision occurs;

[0036] Figure 8 It is a schematic diagram of the output waveform of the oscillator I in the judgment module of the present invention when a collision occurs;

[0037] Fig. 9 It is a schematic diagram of the circuit structure of the delay cut-off module of the present invention; DETAILED DESCRIPTION

[0038] The specific implementation of the present invention is described in detail below with reference to the accompanying drawings and preferred implementation examples.

[0039] like Figure 1 As shown, the present invention provides a specific embodiment of a vehicle door lock backup power supply system, including an anti-backflow module, a delay cut-off module, a charging management module, a backup power supply such as an overcapacitor, a discharge control switch and a delay control module, wherein the delay cut-off module, the discharge control switch and the delay cut-off module are jointly constructed into a control unit, the anti-backflow module is connected in series between the main power supply KL30 and the load Load_KL30 such as a door lock unit on the main circuit, and the overcapacitor is connected to the output end of the anti-backflow module through the charging management module; if the main power supply voltage is normal, the main power supply supplies power to the load through the anti-backflow module, and charges the overcapacitor through the charging management module at the same time, at this time, when the delay control module normally receives the collision signal and the door unlocking signal, it only forwards the signal and does not control the overcapacitor to discharge; if the vehicle collides, the judgment module identifies the collision signal and delays for a period of time, and the delay module turns on the discharge control switch to control the overcapacitor to supply power to the load Load_KL30, and at the same time, the delay cut-off module is used to cut off the electrical connection between the charging management module and the overcapacitor to prevent the overcapacitor from supplying power to the load Load_KL30 in advance during the delay period.

[0040] The details are as follows:

[0041] like Figure 2 As shown in the figure, the backflow prevention module is composed of an ideal diode controller chip and an N-channel MOSFET connected to it, achieving a forward voltage drop as low as 20mV, and ensuring that the current flows unidirectionally from the main power supply KL30 to the load Load_KL30, and there will be no reverse current, so that the energy stored in the supercapacitor will not be released. In addition, when the load Load_KL30 is short-circuited, the current of the N-channel MOSFET tube must be able to meet the requirement of being greater than the fuse action current, and the backflow prevention module cannot be damaged before the fuse is activated. The ideal diode controller chip, that is, the Oring controller chip LM74700, is connected to the source, drain and gate of the N-channel MOSFET tube, and controls the conduction and shutdown of the N-channel MOSFET tube according to the voltage between the source and the gate, realizing low-loss reverse protection.

[0042] like Figure 3As shown, the charging management module uses a PFET Buck switch controller, and the enable port EN is connected to the output end of the ignition signal KL15 through a diode or an ideal diode, which has reverse polarity protection characteristics. After KL15 is powered on, the charging circuit controlled by the PFET Buck switch controller is enabled to charge the overcapacitor, and its input port VIN is connected to the output port of the anti-backflow module, and low-loss reverse protection is achieved through the Oring controller + high-power MOSFET of the anti-backflow module. During charging, the PFET Buck switch controller uses the feedback signal FB to achieve constant on-time control. During the PFET off period, the load current is provided by the inductor and the output capacitor. When the output voltage drops, the feedback input pin FB voltage also drops. When it drops to the threshold, the PFET will turn on immediately; during the PFET on period, the inductor current rises, causing the voltage on the feedback input pin FB to rise until it exceeds the feedback comparison threshold, thereby achieving the output target voltage Vout.

[0043] like Figure 4 As shown, the discharge control switch uses a pair of back-to-back PMOS combination switches, and the switch and disconnection of the pair of tubes are controlled by the delay control module. The input end of the pair of tubes is connected to the output end of the backup power supply, and the output end is connected to the output end of the anti-backflow module, which is used to prevent the main circuit from directly charging the backup power supply, causing overcurrent or overcapacity damage to the charging circuit. Specifically, the discharge control switch includes a pair of back-to-back PMOS tubes, namely a first PMOS tube and a second PMOS tube, both of which have body diodes, the source of the first PMOS tube is connected to the backup power supply, the gate is connected to the drain of the first NMOS tube, the source of the first NMOS tube is grounded, and the gate is connected to the output end of the door unlocking signal; the source of the second PMOS tube is connected to the door lock unit, the gate is connected to the drain of the second NMOS tube, the source of the second NMOS tube is grounded, and the gate is connected to the output end of the first comparator, the negative end of the first comparator is connected to the main power supply, and the positive end is connected to the positive pole of the backup power supply.

[0044] When the tube is turned on, a forward voltage drop of 100mV can be achieved, reducing energy loss when the supercapacitor is powered. The first PMOS tube on the left, namely PMOS1, is driven by the gate unlock signal UNLOCK_CTRL through a first NMOS tube. Under normal conditions, that is, when no collision occurs, UNLOCK_CTRL has no output, the first NMOS tube is in a disconnected state, and PMOS1 is not input with a driving voltage and is in a disconnected state, so the supercapacitor will not discharge Load_KL30.

[0045] When the supercapacitor is in the charging state and Upack < KL30, the first comparator CTRL_1 outputs a low level, the first NMOS transistor is in the off state, the second PMOS transistor, i.e., PMOS2, does not receive the driving voltage and is in the off state, and the current cannot flow from the load KL30 into the supercapacitor, protecting the supercapacitor from being damaged due to excessive charging current.

[0046] When a collision occurs and the main power supply fails, the door unlock signal UNLOCK_CTRL outputs a high level, the first NMOS transistor conducts, and the gate of PMOS1 is grounded. At this time, since the voltage on the supercapacitor side is relatively high, PMOS1 is driven to conduct by the negative gate-source voltage; at the same time, when KL30 is short-circuited or open-circuited due to the collision at the KL30 end and KL30 < Upack, the first comparator CTRL_1 outputs a high level, the second NMOS transistor conducts, and the gate of PMOS2 is grounded. At this time, due to the presence of the body diode in PMOS2, the supercapacitor can directly discharge to the load Load_KL30, the source voltage of PMOS2 increases, thereby generating a negative gate-source voltage, which in turn drives PMOS2 to also conduct, reducing the loss of the output energy of the supercapacitor.

[0047] The function of the delay control module is to output the door unlock signal after delaying for a first predetermined time after receiving and recognizing the collision signal, control the supercapacitor to discharge to Load_KL30, and it is necessary to ensure that the door unlock signal can be normally output. At the same time, it needs to continuously discharge for a second predetermined time to ensure that the action of the door lock unit is completed and the door lock can be completely opened. It mainly has the following functions:

[0048] 1. Delay the output of the door unlock signal

[0049] As Figure 5 shown, in the normal state, that is, when no collision occurs, the discharge control switch S1 is off, the circuit on the backup power supply side is not conducting, and the circuit on the Load_KL30 side is conducting to ensure the normal output of the door unlock signal; when a collision occurs, the circuit on the Load_KL30 side cannot work properly due to the collision, and the main switch S2 on the main power supply side is off. At this time, the delay control module can close S1 after delaying for a first predetermined time to conduct the circuit, thereby outputting the door unlock signal to ensure that the unlocking action can be successfully completed when the backup power supply outputs energy.

[0050] For the vehicle control system, under normal circumstances, the waveform of the collision signal CDS_CTRL is a sawtooth wave. When a collision occurs, the waveform of the collision signal CDS_CTRL is still a sawtooth wave, but the pulse width is narrower than that under normal circumstances. Therefore, the present invention uses two double-trigger monostable multivibrators to construct a delay control module, uses the first double-trigger monostable multivibrator to construct a judgment module, uses the characteristics of the oscillator to realize the detection and processing of the collision signal CDS_CTRL, and judges whether the collision occurs by identifying the pulse width change of the collision signal. Then, the second double-trigger monostable multivibrator is used to construct a delay module. When the collision occurs, the pulse width change of the collision signal CDS_CTRL is monitored, and the Q output of the first double-trigger monostable multivibrator is used as the input of the second double-trigger monostable multivibrator. After a delay of the first predetermined time, the door unlocking signal UNLOCK_CONTROL is output, and at the same time, the closing time of the discharge control switch, that is, the second predetermined time, is controlled to ensure that the door lock unit has enough time to perform the door opening operation.

[0051] The first double-trigger monostable multivibrator and the second double-trigger monostable multivibrator are both powered by a linear regulator LDO, and the input of the LDO is provided by a backup power supply such as a voltage signal of a supercapacitor and an ignition signal KL15 of a vehicle at the same time.

[0052] By attaching Figure 6 The working mode of the double-trigger monostable multivibrator explains the principle of the delay control module in detail:

[0053] The functions of each pin of the double-trigger monostable multivibrator are generally / A for falling edge trigger, B for rising edge trigger, / CLR for rising edge trigger, and the pulse width length of the output pulse signal Q can be adjusted by connecting the resistor R and the capacitor C through the pins Rext / Cext and Cext respectively. The two oscillators of the first double-trigger monostable multivibrator are respectively recorded as oscillator I and oscillator II, and the two oscillators of the second double-trigger monostable multivibrator are respectively recorded as oscillator III and oscillator IV;

[0054] For the first double-trigger monostable multivibrator, in the normal state, i.e., when no collision occurs, the collision signal CDS_CTRL is input to pin B of oscillator I according to the waveform corresponding to the fixed pulse width ta. / A and / CLR are not triggered. At this time, / Q is also output to oscillator II according to the fixed pulse width tw. And in the present invention, the output of pin / Q of oscillator I and the output terminal of the collision signal CDS_CTRL are respectively connected to pin / A of oscillator II through their respective diodes, which is equivalent to using two diodes to parallel the output of the CDS_CTRL signal and pin / Q to form an OR gate. Assuming that the pulse width tw of the waveform output by pin / Q is less than the pulse width ta of the collision signal CDS_CTRL when no collision occurs and greater than the pulse width tb of the collision signal CDS_CTRL when a collision occurs, and the OR gate requires both inputs to be low level to output a low level. As long as any one input is high level, the output must be high level. Due to the setting of the pulse width of the collision signal CDS_CTRL and the pulse width output by pin / Q, when no collision occurs, there is at least one high level at any moment. Therefore, the input of pin / A of oscillator II always remains at a high level. And pin / A of oscillator II is triggered by the falling edge. Therefore, there is no signal output at pin Q of oscillator II, as Figure 7 shown.

[0055] When a collision occurs, the pulse width of the collision signal CDS_CTRL becomes smaller. When ta < tw, a falling edge will be generated in the waveform output by pin / Q of oscillator I, and the input to pin / A of oscillator II will also change, with a falling edge appearing. At this time, it will trigger the output signal of pin Q of oscillator II, as Figure 8 shown.

[0056] At this time, the output pulse width length of pin Q can be controlled by adjusting the resistor R and capacitor C at Rext / Cext and Cext of oscillator II to be greater than the pulse signal of the first predetermined time t1 for the delay and output to pin B of oscillator III, ensuring that during the output of oscillator III, the signal corresponding to the input pin does not change; at the same time, by adjusting Rext / Cext and Cext of oscillator III, a delay pulse of the first predetermined time t1 is generated and output to pin / A of oscillator IV. Pin / A is triggered by the falling edge. Therefore, after the first predetermined time t1 of delay, a falling edge will be generated, which will trigger oscillator IV to generate an output signal. By adjusting Rext / Cext and Cext of oscillator IV, a pulse signal with a pulse width length of the second predetermined time, i.e., the discharge time ton, is output via pin Q to the discharge control module to turn on the switch to cause the backup power supply, such as a supercapacitor, to discharge the door lock unit, and its discharge duration is ton.

[0057] 2. During the delay period, it is controlled that the backup power supply supercapacitor cannot discharge from the charging management module to the load door lock unit

[0058] A delay cut-off module is connected in series between the output end of the charging management module and the backup power supply overcapacity. The discharge cut-off module includes a P-channel MOSFET switch, and a dual-channel comparator controls the closing / opening of the switch to ensure that during the delay period, the backup power supply will not output energy to Load_KL30 through the charging management module. Specifically, Fig. 9 As shown, the delay cut-off module includes a second comparator and a third comparator connected in series, the negative end of the second comparator is connected to the main power supply, the positive end is connected to the positive electrode of the backup power supply, and the output end is connected to the negative end of the third comparator, the positive end of the third comparator is connected to the reference voltage, and the output end is connected to the gate of the third NMOS tube, the source of the third NMOS tube is grounded, and the drain is connected to the gate of the third PMOS tube, namely PMOS3, the third PMOS tube, namely PMOS3, has a body diode, the source is connected to the positive electrode of the backup power supply, and the drain is connected to the charging management module. By comparing the voltages of the main power supply and the backup power supply, the delay cut-off module is triggered to work, and the backup power supply can be cut off to supply power to the door lock unit through the charging management module, thereby ensuring that the door lock unit will not be powered during the delay period, causing the door to be accidentally opened.

[0059] When no collision occurs, the voltage U_Pack of the backup power supply super-capacitor module is less than the load voltage KL30. At this time, the second comparator CTRL_1 of the dual-channel comparator outputs a low level, the third comparator CTRL_2 outputs a high level, the third NMOS tube is turned on, and the gate of the third PMOS tube, namely PMOS3, is grounded. At this time, due to the presence of the body diode of the third PMOS tube, namely PMOS3, the charging management module can charge the super-capacitor, and the source voltage of the third PMOS tube increases to generate a negative gate-source voltage, thereby driving the third PMOS tube to turn on, thereby reducing the voltage drop loss of the charging circuit;

[0060] When a collision occurs and causes the load KL30 end to be short-circuited or open-circuited, the voltage U_Pack of the supercapacitor module is greater than the load voltage KL30, the second comparator CTRL_2 outputs a high level, the third comparator CTRL_3 outputs a low level, the third NMOS tube is in a disconnected state, and the third PMOS tube, i.e., PMOS3, is not input with a driving voltage and is in a disconnected state, ensuring that the supercapacitor will not discharge Load_KL30 through the charging management module during the collision delay period.

[0061] Although specific embodiments of the present invention are described above, those skilled in the art should understand that these are merely examples and that various changes or modifications may be made to these embodiments without departing from the principles and essence of the present invention. Therefore, the scope of protection of the present invention is limited by the appended claims.

Claims

1. A vehicle door lock backup power supply system, characterized in that: It includes a door lock unit and a backup power supply, wherein the backup power supply is connected to the door lock unit through a control unit, and the control unit determines whether the vehicle has collided according to the pulse width change of the collision signal. If the pulse width changes, it is determined that the vehicle has collided, and then the backup power supply is controlled to supply power to the door lock unit after a predetermined delay to achieve unlocking; If the pulse width does not change, it is determined that the vehicle has not collided and no subsequent processing is performed.

2. The vehicle door lock backup power supply system according to claim 1, characterized in that: The control unit includes a judgment module, a delay module and a discharge control switch. The judgment module adopts a double-trigger monostable multivibrator structure to judge whether the pulse width of the collision signal changes; the delay module also adopts a double-trigger monostable multivibrator structure to delay for a first predetermined time after the pulse width of the collision signal changes, and output a door unlocking signal, while closing the discharge control switch to control the backup power supply to continuously supply power to the door lock unit for a second predetermined time to ensure unlocking.

3. The vehicle door lock backup power supply system according to claim 2, characterized in that: The judgment module includes a first double-trigger monostable multivibrator, wherein the two oscillators are respectively recorded as oscillator I and oscillator II; the delay module includes a second double-trigger monostable multivibrator, wherein the two oscillators are respectively recorded as oscillator III and oscillator IV; Pin B of the oscillator I is connected to the output end of the collision signal, and its pin / Q and the collision signal output end are connected to pin / A of the oscillator II through respective diodes, the oscillator II is connected to pin B of the oscillator III, the pin Q of the oscillator III is connected to pin / A of the oscillator IV, and the pin Q of the oscillator IV is connected to the discharge control switch.

4. The vehicle door lock backup power supply system according to claim 3, characterized in that: The pulse width of the output signal of the oscillator I is between the pulse width of the collision signal without collision and the pulse width of the collision signal with collision; The pulse width of the output signal of the oscillator II is greater than the pulse width of the output signal of the oscillator III, and the pulse width of the output signal of the oscillator III is set to a time period of a first predetermined time; The pulse width of the output signal of the oscillator IV is set to the time period of the closing time of the discharge control switch, that is, the second predetermined time.

5. The vehicle door lock backup power supply system according to claim 2, characterized in that: The input end of the judgment module is connected to the output end of the collision signal, and the output end thereof is connected to the input end of the delay module. The output end of the delay module is connected to the discharge control switch, and the discharge control switch is connected between the backup power supply and the door lock unit.

6. The vehicle door lock backup power supply system according to claim 5, characterized in that: The discharge control switch includes a pair of back-to-back PMOS tubes, namely a first PMOS tube and a second PMOS tube, both of which have body diodes, the source of the first PMOS tube is connected to the backup power supply, the gate of the first PMOS tube is connected to the drain of the first NMOS tube, the source of the first NMOS tube is grounded, and the gate of the first NMOS tube is connected to the output end of the door unlocking signal; The source of the second PMOS tube is connected to the door lock unit, and the gate thereof is connected to the drain of the second NMOS tube. The source of the second NMOS tube is grounded, and the gate thereof is connected to the output end of the first comparator. The negative end of the first comparator is connected to the main power supply, and the positive end is connected to the positive pole of the backup power supply.

7. The vehicle door lock backup power supply system according to claim 5, characterized in that: The backup power supply is connected to the main power supply via a delayed cut-off module and a charging management module in sequence. The main power supply is also directly connected to a door lock unit. The delayed cut-off module is used to cut off the connection between the backup power supply and the main power supply during the delay period. The charging management module is used to control the main power supply to charge the backup power supply.

8. The vehicle door lock backup power supply system according to claim 7, characterized in that: The delayed cut-off module includes a second comparator and a third comparator connected in series, wherein the negative end of the second comparator is connected to the main power supply, the positive end thereof is connected to the positive electrode of the backup power supply, and the output end thereof is connected to the negative end of the third comparator, the positive end of the third comparator is connected to the reference voltage, and the output end thereof is connected to the gate of the third NMOS tube, the source of the third NMOS tube is grounded, and the drain thereof is connected to the gate of the third PMOS tube, the third PMOS tube has a body diode, the source thereof is connected to the positive electrode of the backup power supply, and the drain thereof is connected to the charging management module.

9. The vehicle door lock backup power supply system according to claim 6, characterized in that: The main power supply is also connected to the door lock unit through an anti-backflow module, and the anti-backflow module is used to ensure that current can only flow from the main power supply to the door lock unit to prevent reverse flow.

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