Door lock and method for diagnosing opening and closing of door lock

Abstract

The invention relates to a door lock (1) for locking a door (3) of a motor vehicle (2), comprising a diagnosable switch (4) comprising a parallel resistor (6), a switch (7) configured to determine the position of the door (3), and a series resistor (8), the parallel resistor (6) being connected in parallel with the switch (7) and connected in series with the series resistor (8), and a diagnostic circuit (5) for detecting the position of the door (3), comprising a series resistor (8), a pull-up resistor (11) configured to receive a pull-up voltage from a power source (16), a voltage divider (12) comprising a midpoint (13), and a microcontroller (14), where the diode (10) is connected between the series resistor (8) and the voltage divider (12), the midpoint (13) is connected to the microcontroller (14), the diode (10) is connected to the pull-up resistor (11) towards an anode of the voltage divider (12), and the diode (10) is connected to the microcontroller (14) towards a cathode of the voltage divider (12). And the microcontroller (14) is configured to determine whether the midpoint voltage of the midpoint (13) is related to the switching position of the switch (7).

Description

TECHNICAL FIELD

[0001] The invention relates to a door lock for locking a door of a motor vehicle, comprising a diagnosable switch comprising a parallel resistor, a switch configured to determine a position of the door and a series resistor, wherein the parallel resistor is connected in parallel to the switch and in series to the series resistor. The invention further relates to a method for diagnosing a switch of a door lock for locking a door of a motor vehicle, wherein the door lock comprises a diagnosable switch comprising a parallel resistor, a switch configured to determine a position of the door and a series resistor, wherein the parallel resistor is connected in parallel to the switch and in series to the series resistor. BACKGROUND

[0002] Switches are commonly used in automotive door lock applications to sense positions of specific scenarios. Common positions include a "main position" to identify a closed door, an "open position" to identify an open door and a "secondary position" to identify an intermediate state close to the "main position".

[0003] Such switches involve several safety requirements that need to be diagnosed in depth by dedicated circuits and methods to ensure that the diagnosis is continuously performed in normal and energy saving modes.

[0004] In terms of circuits, diagnosable switches are commonly used (e.g. with a structure of parallel and series resistors built-in). However, the circuits and related methods of the prior art often do not meet the safety requirements, especially in energy saving mode. SUMMARY

[0005] It is therefore an object of the invention to provide a simple, economic and / or reliable solution for improving the diagnosis technology of door lock switches.

[0006] The objects of the invention are solved by the features of the independent claims. Preferred embodiments are specified in the dependent claims.

[0007] The above objects are therefore achieved by a door lock for locking a door of a motor vehicle, comprising:

[0008] a diagnosable switch comprising a parallel resistor, a switch configured to determine a position of the door and a series resistor, wherein the parallel resistor is connected in parallel to the switch and in series to the series resistor; and

[0009] a diagnosis circuit comprising a diode, a pull-up resistor configured to receive a pull-up voltage from a power supply, a voltage divider comprising a midpoint, and a microcontroller, wherein the diode is connected between the series resistor and the voltage divider, the midpoint is connected to the microcontroller, the anode of the diode towards the voltage divider is connected to the pull-up resistor, and the microcontroller is configured to determine whether a midpoint voltage of the midpoint is related to a switch position of the switch.

[0010] The proposed door lock and the corresponding method described below provide a simple and reliable solution for continuous diagnostics of the switch during normal operation and in energy-saving mode, particularly suitable for performing diagnostic routines for the switch, the diagnostic switch, and / or the door lock. The proposed diagnostic circuitry can detect open-circuit, battery short-circuit, and ground short-circuit faults in the switch or the diagnostic switch, respectively. For example, in an open-circuit condition, the diode isolates the diagnostic circuitry from the diagnostic switch and allows external devices (e.g., via Advanced Driver Assistance Systems (ADAS) devices) to connect via a pull-up voltage.

[0011] The power source can be the vehicle's main power source, preferably provided by the vehicle's battery, for example, providing 12 or 24 V DC power. The door lock preferably includes a motor configured to actuate the door lock to lock and unlock the vehicle's doors. More generally, "door lock" should be understood as a device for locking a movable element between an open and closed position, thereby opening and closing access to the interior compartments of the vehicle, including, for example, the trunk, tailgate, hood or other enclosed compartments, window regulators, sunroof, and side doors of the vehicle.

[0012] The vehicle can be an electric vehicle. The door lock may include a housing made of metal, plastic, or a combination thereof. In particular, the electric motor, the diagnostic switch, and the diagnostic circuit are preferably housed within this housing. Furthermore, the diagnostic switch and the diagnostic circuit may be housed within an electronic housing disposed within the housing and / or the door lock.

[0013] According to a preferred embodiment, the microcontroller is provided as a system base chip, a microprocessor, and / or may be part of a door lock and / or an electronic control unit (ECU) of a motor vehicle. The system base chip is preferably provided as an integrated circuit that integrates multiple functions of the automotive electronic control unit (ECU) on a single chip. The system base chip and / or the microcontroller may include embedded functions such as voltage regulators, monitoring functions, reset generators, watchdog functions, bus interfaces (e.g., local interconnect network (LIN), CAN bus, etc.), wake-up logic, and / or power switches. The microcontroller preferably includes analog input peripherals connected to this midpoint, such as analog-to-digital converters (ADCs). The term "connection" should preferably be understood as electrical connection.

[0014] The switch or the diagnostic switch is preferably operatively and / or mechanically connected to the door to determine the door's position. This position can be, for example, closed ("main position"), open ("open"), and / or an intermediate position near the closed position ("intermediate position"). The diode can be any diode known in the art that allows current to flow primarily in one direction. The pull-up resistor is preferably connected to the power supply. The diode is preferably connected with its cathode to one end of the series resistor, while the other end of the series resistor is connected to the parallel resistor. Determining whether the midpoint voltage is related to the switch's position specifically means checking whether the switch position matches the corresponding and / or estimated voltage of the midpoint voltage. For example, if the midpoint voltage is zero, a fault exists (e.g., a short circuit to ground); if the midpoint voltage is equal to the voltage of the power supply, a fault also exists (e.g., a short circuit to the power supply); if the midpoint voltage is close to a low threshold (e.g., 1V), the determined location is valid; if the midpoint voltage is close to a high threshold (e.g., 3V), the determined location is valid; and if the midpoint voltage is close to an open circuit voltage threshold (e.g., 2V), a fault also exists.

[0015] According to a preferred embodiment, the parallel resistor, the switch, and / or the voltage divider are grounded at one end. Preferably, the other ends of the switch and the parallel resistor are connected to each other. The voltage divider preferably comprises two resistors connected in series, with the midpoint located at the junction of the two resistors.

[0016] In another preferred embodiment, the door lock, particularly the diagnostic circuit, includes a filter capacitor connected to the midpoint and preferably grounded. Specifically, one end of the filter capacitor is connected to the midpoint, while the other end is grounded. The filter capacitor is preferably configured to filter out low-frequency components.

[0017] According to another preferred embodiment, the door lock, particularly the diagnostic circuit, includes a pull-up switch connected to the pull-up resistor (specifically, one end of the pull-up resistor) and configured to receive the pull-up voltage from the power supply, wherein the microcontroller is configured to switch the pull-up switch. The pull-up switch may be an electronic switch, such as a transistor or MOSFET.

[0018] In another preferred embodiment, the microcontroller is configured to determine whether the pull-up voltage at the midpoint is related to the switch's position, specifically only when the pull-up switch is on. Preferably, the microprocessor uses a polling pulse method (e.g., by periodic pulses with a very low duty cycle) to switch the voltage that can be received by the pull-up resistor. In this respect, the microcontroller preferably reads the midpoint voltage only when a pulse is activated. The midpoint voltage is preferably compared with the switch state for verification before initiating any action related to the door position.

[0019] According to another preferred embodiment, the microprocessor is configured to periodically and / or continuously switch the voltage that can be received by the pull-up resistor. Preferably, the microprocessor is configured to periodically and / or continuously determine whether the midpoint voltage is related to the switching position of the switch.

[0020] In another preferred embodiment, the microcontroller is configured to issue a fault signal if the midpoint voltage is not related to the switch position. If such a fault is detected regarding the fault signal, the microcontroller can notify of the fault on a bus interface, such as via a CAN or LIN interface, so that internal and / or external safety actions can be assessed and hazards avoided. Alternatively or additionally, the fault signal can be sent to the vehicle's electronic control unit (ECU).

[0021] According to another preferred embodiment, the microcontroller includes an energy-saving mode with a corresponding wake-up function, and the microcontroller is configured to determine, upon wake-up, whether the midpoint voltage of the midpoint is related to the switching position of the switch. During such an energy-saving mode, the power consumption of the microcontroller is reduced compared to the normal operating mode, for example, by 50%, 70%, 90%, or 100%. This wake-up function can be triggered, in particular, by an internal handle trigger. In such cases, when action is required, the proposed diagnostic routine can be executed, and only safety actions are performed. The diagnostic routine can be re-executed before the microcontroller enters the energy-saving mode. Thus, the additional power consumption caused by periodic wake-ups solely for diagnostic purposes can be avoided, since during energy-saving mode, the vehicle battery may be depleted and / or other bus devices may be unable to operate on the main bus interface (e.g., via CAN and / or LIN buses).

[0022] This objective is also achieved by a motor vehicle that includes door locks as described above and a battery as a power source.

[0023] This objective is also achieved by a method for diagnosing the switch of a door lock used to lock a motor vehicle door, wherein the door lock includes:

[0024] A diagnostic switch includes a parallel resistor, a switch configured to determine the position of a vehicle door, and a series resistor, wherein the parallel resistor is connected in parallel with the switch and in series with the series resistor.

[0025] A diagnostic circuit, including a diode, a pull-up resistor configured to receive a pull-up voltage from a power supply, and a voltage divider including a midpoint, wherein the diode is connected between the series resistor and the voltage divider, and the diode is connected to the pull-up resistor toward the anode of the voltage divider, the method comprising the steps of:

[0026] Determine whether the midpoint voltage is related to the switch position.

[0027] According to a preferred embodiment, the door lock includes a pull-up switch connected to the pull-up resistor and configured to receive a pull-up voltage from the power supply. The method includes the following steps:

[0028] Switch the pull-up switch.

[0029] In another preferred embodiment, the method includes the following steps:

[0030] When the pull-up switch is turned on, determine whether the midpoint voltage is related to the switch position.

[0031] According to a further preferred embodiment, the method includes the following steps:

[0032] The voltage that the pull-up resistor can accept is switched periodically and / or continuously.

[0033] In another preferred embodiment, the method includes the following steps:

[0034] If the midpoint voltage is not related to the switch position, a fault signal is issued.

[0035] According to a further preferred embodiment, the diagnostic circuit specifically includes a microprocessor connected to the midpoint, wherein the microcontroller includes an energy-saving mode with a corresponding wake-up function, and includes the following steps:

[0036] After waking up the microprocessor, determine whether the midpoint voltage is related to the switch position.

[0037] Those skilled in the art can derive further implementation schemes and advantages of this method from the door lock described above. Attached Figure Description

[0038] These and other aspects of the invention will become apparent from and be explained with reference to the embodiments described below.

[0039] In the attached diagram:

[0040] Figure 1 A schematic circuit diagram of a diagnostic switch and diagnostic circuit for a vehicle door lock, according to a preferred embodiment, is shown. Detailed Implementation

[0041] Figure 1 A schematic circuit diagram is shown, in which only a door lock 1 for locking the door 3 of a vehicle 2 (shown only schematically). The vehicle 2 includes four side doors, one of which, 3, is located at... Figure 1The diagram illustrates that each vehicle door is equipped with a door lock 1. In addition to the side doors 3 of the vehicle 2, the door lock 1 can also be associated with the rear hatch, hood or other enclosed compartments, window regulators, and sunroof.

[0042] The door lock 1 includes a housing made of plastic, metal, or a combination thereof. Within this housing, particularly within a separate electronic housing (not shown), are arranged a diagnostic switch and diagnostic circuit 5.

[0043] The diagnostic switch 4 includes a parallel resistor 6, a switch 7 configured to determine the position of the door 3, and a series resistor 8. The parallel resistor 6 and the switch 7 are connected in parallel with one end grounded 9. The other end is connected to the series resistor 8, such that the parallel resistor 6 and the series resistor 8 are connected in parallel. The switch 7 provides a mechanical switch operably connected to the door 3.

[0044] The diagnostic circuit 5 includes a diode 10, a pull-up resistor 11, a voltage divider 12 including a midpoint 13, a microcontroller 14, and optionally a filter capacitor 15. The diode 10 has its cathode connected to the other end of the series resistor 8, such that the series resistor 8 is connected between the cathode and the parallel resistor 6. The anode of the diode 10 is connected to the pull-up resistor 11 and one end of the voltage divider 12.

[0045] The voltage divider 12 includes two resistors connected in series, forming the midpoint 13 between the two resistors. The other end of the voltage divider 12 is grounded at 9. The filter capacitor 15 is connected between the midpoint 13 and grounded at 9, i.e., in parallel to one of the two resistors in the voltage divider 12. The microcontroller 14 includes an analog input peripheral, such as an analog-to-digital converter (ADC), whose input is connected to the midpoint 13.

[0046] The vehicle 2 includes a main power supply 16, which is provided by a standard vehicle battery known in the prior art and provides a main power supply voltage of 12 VDC. The main power supply voltage is supplied to the other end of the pull-up resistor 11 via a pull-up switch 17. The electronically controlled pull-up switch 17 is switched by the microcontroller 14, specifically via the digital-to-analog converter output of the microcontroller 14.

[0047] This diagnostic circuit 5 can detect open circuits, battery short circuits (i.e., main power supply 16 short circuits), and ground 9 short circuits. Therefore, diode 10 isolates the diagnostic circuit 5 when switch 7 is open, allowing external device connection. During test routine operation, the main power supply voltage of main power supply 16 is supplied to the pull-up resistor 11 controlled by the pull-up switch 17 operated by microcontroller 14, and subsequently to the midpoint 13. Microcontroller 14 can thus determine whether the midpoint voltage of midpoint 13 is related to the switching position of switch 7.

[0048] The voltage supplied to the pull-up resistor 11 by the pull-up switch 17 is periodically controlled by the microcontroller 14 according to a polling pulse method. When a pulse is activated, the microcontroller 14 reads an analog value from the midpoint 13 and determines whether the value is acceptable / valid before performing any action (e.g., confirming the state of the switch 7 with the control unit of the vehicle 2). Therefore, the microcontroller 14 is provided as an SBC (System Base Chip).

[0049] During the normal operation of the door 3, the diagnostics provided by the diagnostic switch 4 and the diagnostic circuit 5 are continuous: if a fault is detected in the switch 7, the fault will be notified on the bus interface of the microcontroller 14 (e.g., provided as CAN or LIN), so that the internal safety actions of the vehicle 2 can be evaluated and the vehicle 2 or the door 3 can be prevented from falling into a dangerous state.

[0050] The microcontroller 14 includes a power-saving mode with a corresponding wake-up function, wherein upon wake-up, the microcontroller 14 determines whether the midpoint voltage of the midpoint 13 is related to the switching position of the switch 7. During such a power-saving mode, reduced power consumption is desired. Therefore, the diagnostic routine is executed only when action is required, such as via an internal handle trigger. In this case, only a safety action is performed, prior to which the microcontroller 14 is placed in the aforementioned power-saving mode to re-execute the diagnostic routine. This method thus avoids the additional power consumption caused by periodic wake-ups solely for diagnostic purposes, since during power-saving mode, the main power supply 16 is unavailable, and other bus devices cannot operate on the bus interface.

[0051] While the invention has been illustrated and described in detail in the accompanying drawings and foregoing description, such illustrations and descriptions should be considered illustrative or exemplary rather than restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be realized by those skilled in the art who, in practicing the claimed invention, study the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality. The fact that certain measures are recited only in mutually different dependent claims does not mean that a combination of these measures cannot be used advantageously. Any reference signs in the claims should not be construed as limiting the scope.

[0052] Figure Labels

[0053] 1. Car door lock

[0054] 2 Motor vehicles

[0055] 3 doors

[0056] 4. Diagnostic switch

[0057] 5. Diagnostic Circuit

[0058] 6 Parallel resistors

[0059] 7 Switches

[0060] 8 Series resistors

[0061] 9. Grounding

[0062] 10 Diodes

[0063] 11 Pull-up resistor

[0064] 12 voltage divider

[0065] 13 Midpoint

[0066] 14 Microcontrollers

[0067] 15. Filter capacitors

[0068] 16 Power Supply

[0069] 17 Pull-up switch

Claims

1. A door lock (1) for locking the doors (3) of a motor vehicle (2), including The diagnostic switch (4) includes a parallel resistor (6), a switch (7) configured to determine the position of the door (3), and a series resistor (8), wherein the parallel resistor (6) is connected in parallel with the switch (7) and in series with the series resistor (8), and The diagnostic circuit (5) includes a diode (10), a pull-up resistor (11) configured to receive a pull-up voltage from a power supply (16), a voltage divider (12) including a midpoint (13), and a microcontroller (14), wherein the diode (10) is connected between the series resistor (8) and the voltage divider (12), the midpoint (13) is connected to the microcontroller (14), the diode (10) is connected to the pull-up resistor (11) with the anode of the voltage divider (12), and the microcontroller (14) is configured to determine whether the midpoint voltage of the midpoint (13) is related to the switching position of the switch (7).

2. The door lock according to the preceding claim, wherein, The switch (7), the parallel resistor (6), and the voltage divider (12) are grounded (9).

3. The door lock (1) according to any one of the preceding claims includes a filter capacitor (15) connected to the midpoint (13) and preferably grounded (9).

4. The door lock (1) according to any one of the preceding claims includes a pull-up switch (17) connected to the pull-up resistor (11) and configured to receive a pull-up voltage from the power supply (16), wherein the microcontroller (14) is configured to switch the pull-up switch (17).

5. The door lock (1) according to the preceding claim, wherein, The microcontroller (14) is configured to determine whether the pull-up voltage at the midpoint (13) is related to the switching position of the switch (7) when the pull-up switch (17) is turned on.

6. The door lock (1) according to any one of the preceding claims, wherein, The microcontroller (14) is configured to periodically and / or continuously switch the voltage that the pull-up resistor (11) can receive.

7. The door lock (1) according to any one of the preceding claims, wherein, The microcontroller (14) is configured to issue a fault signal if the midpoint voltage is not related to the switch position.

8. The door lock (1) according to any one of the preceding claims, wherein, The microcontroller (14) includes an energy-saving mode with a corresponding wake-up function, and the microcontroller (14) is configured to determine after wake-up whether the midpoint voltage of the midpoint (13) is related to the switch position of the switch (7).

9. A motor vehicle (2) comprising a door lock (1) according to any one of the preceding claims and a battery as a power source (16).

10. A method for diagnosing the switch (7) of a door lock (1) for locking a door (3) of a motor vehicle (2), wherein the door lock (1) comprises: The diagnostic switch (4) includes a parallel resistor (6), a switch (7) configured to determine the position of the door (3), and a series resistor (8), wherein the parallel resistor (6) is connected in parallel with the switch (7) and in series with the series resistor (8), and The diagnostic circuit (5) includes a diode (10), a pull-up resistor (11) configured to receive a pull-up voltage from a power supply (16), and a voltage divider (12) including a midpoint (13), wherein the diode (10) is connected between the series resistor (8) and the voltage divider (12), and the diode (10) is connected to the pull-up resistor (11) toward the anode of the voltage divider (12). The method includes the following steps: Determine whether the midpoint voltage of the midpoint (13) is related to the switch position of the switch (7).

11. The method according to the preceding claim, wherein, The door lock (1) includes a pull-up switch (17) connected to the pull-up resistor (11) and configured to receive a pull-up voltage from a power source (16). The method includes the following steps: Switch the pull-up switch (17).

12. The method according to any one of the preceding claims, comprising the following steps: When the pull-up switch (17) is turned on, determine whether the midpoint voltage of the midpoint (13) is related to the switch position of the switch (7).

13. The method according to any one of the preceding claims, comprising the following steps: The voltage that the pull-up resistor (11) can accept is switched periodically and / or continuously.

14. The method according to any one of the preceding claims, comprising the following steps: If the midpoint voltage is not related to the switch position, a fault signal is issued.

15. The method according to any one of the preceding claims, comprising a microcontroller (14) connected to the midpoint (13), wherein the microcontroller includes a power-saving mode with a corresponding wake-up function, the method comprising the steps of: After waking up the microcontroller (14), determine whether the midpoint voltage of the midpoint (13) is related to the switch position of the switch (7).

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