Discharge circuit for vehicle wiper motor and wiper system comprising discharge circuit

Abstract

A discharge circuit for a vehicle wiper motor and a wiper system comprising the discharge circuit. The discharge circuit is provided in a domain controller, and the domain controller is configured to control a power supply to supply power to the wiper motor; the wiper motor comprises a winding; the discharge circuit comprises: a low-side driver (LSD) circuit configured to release a voltage induced in the winding, wherein a first end of the LSD circuit is connected between the power supply and the winding of the wiper motor, and a second end of the LSD circuit is connected to the ground; the LSD circuit comprises a semiconductor switching device and a resistor which are connected in series between the power supply and the ground; when the domain controller controls the power supply to supply power to the wiper motor to drive a wiper to operate, the LSD circuit is controlled to be disconnected by the domain controller; and when the domain controller controls the power supply to stop supplying power to the wiper motor, the LSD circuit is controlled to be connected by the domain controller so as to release the induced voltage in the winding. The discharge circuit of the present disclosure can enable the induced voltage in the motor winding to be quickly conducted to the ground.

Description

Discharge circuit for vehicle wiper motor and wiper system including the discharge circuit Technical Field

[0001] The present invention relates to an electronic circuit, in particular to a discharge circuit for a vehicle wiper motor. Background Art

[0002] Currently, vehicles generally include windshield wipers (also known as windshield wipers or windshield wipers, etc.) for clearing rain, snow, ice, washer fluid, water, or debris from the windshield of the cab.

[0003] Most windshield wipers are driven by a wiper motor with windings. Users can activate the wipers based on weather conditions or cleaning needs, and the wipers are driven to repeatedly oscillate across the windshield to clean. After the wipers are finished using the wipers, the user can choose to stop the wiper motor from being powered. However, even after the wiper motor is powered off, induced voltage may still exist in the motor's windings. This induced voltage may adversely affect the wiper's power supply circuitry, resulting in an uncomfortable or unsafe user experience.

[0004] Summary of the Invention

[0005] The present disclosure provides a discharge circuit for a vehicle wiper motor, wherein the discharge circuit is arranged in a domain controller, the domain controller is configured to control a power supply to supply power to the wiper motor, the domain controller is connected to the power supply and the wiper motor, the power supply is configured to supply power to the wiper motor; the wiper motor includes a winding and is configured to drive a wiper operation through the winding; wherein the discharge circuit includes: a low-side drive (LSD) circuit for releasing a voltage induced in the winding, wherein a first end of the low-side drive (LSD) circuit is connected between the power supply and the winding of the wiper motor, and a second end of the low-side drive (LSD) circuit is connected to ground, wherein the low-side drive (LSD) circuit includes a semiconductor switching device and a resistor connected in series between the power supply and ground, and the low-side drive (LSD) circuit is controlled to be turned on and off by the semiconductor switching device; wherein when the domain controller controls the power supply to supply power to the wiper motor to drive the wiper operation, the low-side drive (LSD) circuit is controlled to be turned off by the domain controller, and when the domain controller controls the power supply to stop supplying power to the wiper motor, the low-side drive (LSD) circuit is controlled to be turned on by the domain controller to release the induced voltage in the winding.

[0006] According to the discharge circuit of the present disclosure, the semiconductor switch device included in the low-side drive (LSD) circuit includes one or more of a MOS device and an IGBT device.

[0007] According to the discharge circuit disclosed herein, the low-side drive LSD circuit is selected according to the size of the discharge current generated by the induced voltage and the discharge duration.

[0008] According to the discharge circuit of the present disclosure, the resistor is at least used for current limiting.

[0009] According to the discharge circuit disclosed herein, the domain controller further includes a micro-control unit MCU, and the domain controller controls whether the power supply is supplied to the wiper motor and the on and off of the low-side drive LSD circuit through the micro-control unit MCU.

[0010] According to the discharge circuit of the present disclosure, the domain controller further monitors, through the micro control unit MCU, the voltage outputted by the power supply to the wiper motor via the discharge circuit for the vehicle wiper motor.

[0011] According to the discharge circuit disclosed herein, the low-side driver LSD circuit includes a diagnostic pin, and the domain controller further diagnoses whether the low-side driver LSD circuit is faulty via the diagnostic pin of the low-side driver LSD circuit through the micro-control unit MCU.

[0012] According to the discharge circuit of the present disclosure, the low-side drive LSD circuit includes an LSD power supply, wherein the LSD power supply is configured to supply power for diagnostic operations of the low-side drive LSD circuit and provide at least a portion of a control voltage for controlling the on and off of a semiconductor switching device, and the LSD power supply is turned off when the low-side drive LSD circuit is dormant.

[0013] According to the discharge circuit disclosed herein, it also includes a reverse polarity protection circuit, wherein one end of the reverse polarity protection circuit is connected to the low-side drive LSD circuit, and the other end of the reverse polarity protection circuit is connected between the power supply and the wiper motor, and the reverse polarity protection circuit is used to protect the power supply from the reverse polarity voltage generated by the low-side drive LSD circuit.

[0014] The discharge circuit according to the present disclosure further includes an electrostatic discharge (ESD) protection circuit, which is configured to at least partially reduce the induced voltage in the winding.

[0015] The present disclosure provides a domain controller, including the discharge circuit according to the present disclosure described above. Detailed features of the domain controller according to the present disclosure are described above in the description of the discharge circuit, which will not be repeated here for the sake of simplicity.

[0016] The present disclosure provides a motor vehicle including the discharge circuit and / or the domain controller described above. Detailed features of the motor vehicle according to the present disclosure are described above with reference to the discharge circuit and the domain controller, and are omitted for brevity.

[0017] The present disclosure provides a wiper system, comprising: a wiper module, the wiper module comprising: a wiper motor, the motor comprising one or more windings, the motor being configured to use power from a power module to drive a wiper through the one or more windings, the wiper being operably coupled to one of the one or more windings; a power module, the power module being configured to supply power to the wiper module; an inductive voltage release module, the inductive voltage release module being disposed in a domain controller, the domain controller being configured to control the power module to supply power to the wiper module, the domain controller being connected to the power module and the wiper module, the inductive voltage release module comprising at least one low-side drive LSD circuit, the at least one low-side drive LSD circuit corresponding to one of the one or more windings The low-side drive LSD circuit is used to release the voltage induced in the winding, wherein the first end of the low-side drive LSD circuit is connected between the power module and the winding of the wiper motor, and the second end of the low-side drive LSD circuit is connected to the ground, wherein the low-side drive LSD circuit includes a semiconductor switching device and a resistor connected in series between the power module and the ground, and the low-side drive LSD circuit is controlled to be turned on and off by the semiconductor switching device; wherein, when the domain controller controls the power module to supply power to the wiper motor to drive the wiper operation, the low-side drive LSD circuit is controlled to be disconnected by the domain controller, and when the domain controller controls the power module to stop supplying power to the wiper motor, the low-side drive LSD circuit is controlled to be turned on by the domain controller to release the induced voltage in the winding.

[0018] According to the discharge circuit and wiper system disclosed herein, when the power supply is normally supplying power to the wiper motor, the discharge circuit is turned off. When the power supply stops supplying power to the wiper motor, the discharge circuit is controlled to be turned on, so that the induced voltage existing in the winding of the wiper motor can be conducted to the ground through the discharge circuit. The discharge circuit can quickly conduct the large current generated by the induced voltage existing in the winding of the wiper motor to the ground, so that the wiper can stop at the position desired by the user. The switch that turns on and off the large current generated by the induced voltage in the discharge circuit is a semiconductor switching device, and there is no problem of arcing or electric sparks, so the number of uses or lifespan is significantly longer. In addition, the discharge circuit can be turned on and off in a controlled manner according to user instructions, so it is more flexible. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0020] Figure 1 is a windshield wiper usage scenario;

[0021] Figure 2a is a windshield wiper system;

[0022] Figure 2b is another wiper system;

[0023] FIG3 is a discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure;

[0024] FIG4 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure;

[0025] FIG5 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure;

[0026] FIG6 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure;

[0027] FIG7 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure;

[0028] FIG. 8 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure.

[0029] FIG. 9 is a windshield wiper system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0030] Before proceeding with the following detailed description, it may be advantageous to set forth the definitions of certain words and phrases used throughout this disclosure. The terms "comprise" and "include" and their derivatives mean including, but not limited to. The term "controller" or "control unit" means any device, system, or part thereof that controls at least one operation. Such a controller may be implemented in hardware, or a combination of hardware and software and / or firmware. The functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. The phrase "at least one of," when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item from the list may be required. For example, "at least one of A, B, C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, A and B and C.

[0031] Definitions for other specific words and phrases are provided throughout this disclosure. Those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior and future uses of such defined words and phrases.

[0032] The various embodiments of the principles of the present disclosure described below in conjunction with the accompanying drawings are merely illustrative and should not be construed as limiting the scope of the present disclosure in any way. It will be understood by those skilled in the art that the principles of the present disclosure can be implemented in any appropriately arranged system or device. In some cases, the actions described in the present disclosure can be performed in a different order and still achieve the desired result. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or the sequential order to achieve the desired result. In specific embodiments, multitasking and parallel processing may be advantageous.

[0033] The text and drawings are provided as examples only to aid understanding of the present disclosure. They should not be construed as limiting the scope of the claims appended hereto in any way. Although certain embodiments and examples have been provided, it will be apparent to those skilled in the art based on the contents of this disclosure that modifications may be made to the embodiments and examples shown without departing from the scope of this disclosure.

[0034] Figure 1 shows a scenario where wipers are used.

[0035] The wiper usage scenario shown in FIG1 includes a windshield 110 and a wiper 120 .

[0036] Windshield 110 can be positioned at front window or rear window and other possible positions of vehicle.For the purpose of clear vision, need to use windshield wiper 120 to clean windshield 110.

[0037] The wiper 120 may be configured to be driven by a wiper motor to swing repeatedly to clean the windshield 110 .

[0038] Figure 2a shows a windshield wiper system.

[0039] The windshield wiper system shown in FIG2a can be installed in various vehicles. Vehicles include, but are not limited to, cars, tractors (with or without trailers), buses, recreational vehicles, minivans or sport utility vehicles (SUVs), construction equipment, agricultural equipment, aircraft, etc. As shown in FIG2a , the windshield wiper system may include a power supply 210 , a wiper motor 220 , and a wiper 120 .

[0040] The power source 210 may be configured to provide an input voltage to the wiper motor 220. The power source 210 may be a battery of the vehicle, such as a nickel-cadmium battery, a nickel-metal hydride battery, a lithium-ion battery, a polymer battery, a lead-acid battery, or the like.

[0041] The wiper motor 220 can be configured to receive an input voltage from the power supply 210 and drive the wiper 120 via a winding 222. The wiper motor 220 can include DC motors such as permanent magnet DC motors and electromagnetic DC motors, as well as AC motors such as synchronous AC motors and asynchronous AC motors. As shown in FIG2 a , the wiper motor 120 can include a single winding 222. However, those skilled in the art will appreciate that the wiper motor 220 can include more windings. For example, more windings with different numbers of turns can correspond to more speed modes.

[0042] The wipers 120 may include one or more of a boned wiper, a boneless wiper, and a composite wiper. The wipers 120 may be configured to be driven by a wiper motor 220 using a winding 222 to remove rain, snow, ice, washer fluid, water, or debris from the windshield.

[0043] Referring now to FIG. 2 a , the wiper usage scenario of FIG. 1 will be described. In the scenario of FIG. 1 , the user can activate the wiper 120 based on weather conditions or cleaning needs. The wiper 120 can be driven to repeatedly oscillate across the windshield 110 for cleaning. After the wiper 120 is finished using the wiper 120, the user can choose to stop powering the wiper motor 220. However, even after power is removed from the wiper motor 220, an induced voltage may still be present in the winding 222 of the wiper motor 220. For example, at time T1, the user can instruct the power supply 110 to stop powering the wiper motor 220 to stop the wiper 120. However, due to the induced voltage still present in the winding 222, the wiper 120 may continue to move and stop at time T3. The position at which the wiper 120 finally stops at time T3 may not be the user's desired position and may obstruct the user's field of vision. This can cause discomfort to the user and pose a potential safety hazard. Furthermore, the induced voltage in the winding 222 may be of reverse polarity relative to the supply voltage of the power supply 110 , and thus may be harmful to the power supply 110 .

[0044] Figure 2b shows another wiper system.

[0045] The components in FIG2b that are the same as those in FIG2a are not described again. The wiper system in FIG2b further includes a transient voltage suppression (TVS) diode or a Zener diode 230 .

[0046] Referring now to Figure 2b , the wiper usage scenario of Figure 1 will be described. In the scenario of Figure 1 , after the wiper motor 220 driving the wiper 120 is powered off, an induced voltage still exists in the winding 222 of the wiper motor 220. For example, at time T1, the user can instruct the power supply 110 to stop powering the wiper motor 220 to stop the wiper 120. However, due to the induced voltage still existing in the winding 222, the wiper 120 may continue to be driven. In this case, the TVS diode or Zener diode 230 may activate and discharge the induced voltage in the winding 222 of the wiper motor 220. However, the induced voltage in the winding 222 is large, and the TVS diode or Zener diode 230 has limited ability to discharge the induced voltage, resulting in a slow discharge rate. Therefore, the wiper 120 may stop at time T2, which is slightly shorter than time T3. The position at which the wiper 120 finally stops at time T2 may still not be the user's desired position and may interfere with the user's field of view. This creates an uncomfortable experience for the user and may pose a safety hazard. Furthermore, the induced voltage in winding 222 may have the opposite polarity to the supply voltage of power supply 110, potentially damaging power supply 110. Furthermore, the TVS diode or Zener diode 230 is not user-controllable and only activates when the induced voltage reaches its threshold, thus limiting flexibility.

[0047] FIG3 is a discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure.

[0048] Components identical to those in Figure 2a are not described again in Figure 3. The discharge circuit in Figure 3 also includes a low-side driver (LSD) circuit 310 and a domain controller 230. As shown in Figure 3, the low-side driver (LSD) circuit 310 is located within the domain controller 230. The low-side driver (LSD) circuit 310 within the domain controller 230 can be used to discharge voltage induced in the windings. As shown in Figure 3, the first end of the low-side driver (LSD) circuit 310 is connected between the power supply and the windshield wiper motor windings, while the second end of the low-side driver (LSD) circuit is connected to ground. The domain controller or regional controller 230 can be the core of each functional domain in the vehicle. Leveraging its high-performance domain master processor, extensive hardware interface resources, and powerful software features, the domain controller can integrate core functions that would otherwise require multiple vehicle control units (ECUs), significantly improving system integration. Furthermore, the standardized data exchange interface significantly reduces development and manufacturing costs for these functions. The domain controller 230 can be connected to the power supply 210 and the wiper motor 220. The domain controller 230 may control the power supply 210 to supply power to the wiper motor 220 , and control the on and off of the low-side drive LSD circuit 310 .

[0049] The low-side drive LSD circuit 310 may include a semiconductor switch device 311 and a resistor 322 connected in series between a power supply and ground. As shown in Figure 3, one end of the semiconductor switch device 311 of the low-side drive LSD circuit 310 can be connected between the power supply 210 and the wiper motor 220, and the other end of the semiconductor switch device 311 can be connected to a resistor 312, and the other end of the resistor 312 can be connected to the ground. Other series connection modes are also possible. The resistor 312 can, for example, play a role in current limiting. As will be understood by those skilled in the art, the low-side drive LSD circuit 310 may also include other components, which will not be described in detail herein. The low-side drive LSD circuit 310 may receive an LSD control signal (not shown) from the domain controller 230 to control the low-side drive LSD circuit 310 to be turned on and off through the semiconductor switch device 311.

[0050] In one embodiment, when the domain controller 230 controls the power supply 210 to supply power to the wiper motor 220 to drive the wiper operation, the low-side driver LSD circuit may receive an LSD control signal from the domain controller 230 indicating a disconnection. The LSD control signal sent by the domain controller 230 may be associated with a user's instruction regarding whether the power supply 210 is supplying power to the wiper motor 220. In response to the control signal indicating a disconnection, the low-side driver LSD circuit may be controlled to disconnect via the semiconductor switching device 311. In this case, the low-side driver LSD circuit 310 does not affect the power supply to the wiper motor 220 by the power supply 210.

[0051] In one embodiment, when the domain controller 230 controls the power supply 210 to stop supplying power to the wiper motor 220, the low-side driver (LSD) circuit can receive a control signal from the domain controller 230 instructing it to turn on. In response to the control signal instructing it to turn on, the low-side driver (LSD) circuit can be controlled to turn on via the semiconductor switching device 311. At this point, the high current generated by the induced voltage in the winding 222 of the wiper motor 220 can be quickly conducted to ground via the low-side driver (LSD) circuit 310. In the example scenario of FIG. 1 , the position at which the wiper 120 finally stops can be substantially the same as the position at time T1 when the user instructs the wiper motor 220 to stop supplying power. Therefore, the user can control the wiper 120 to stop at the desired position. Furthermore, because the induced voltage in the winding 222 of the wiper motor 220 is quickly discharged, the power supply 210 can be protected from damage. Furthermore, because the low-side driver circuit LSD conducts and disconnects the high current generated by the induced voltage via the semiconductor switching device 311, there is no arcing or sparking associated with electromagnetic relays or traditional mechanical switches. Therefore, the low-side driver circuit LSD significantly increases its service life. Furthermore, the discharge circuit can be controlled to conduct and disconnect based on a user-instructed control signal, providing greater flexibility.

[0052] In one embodiment, the semiconductor switch device 311 may include a MOS device. For example, the semiconductor switch device 311 may include one or more of a P-channel enhancement MOS device, a P-channel depletion MOS device, an N-channel enhancement MOS device, and an N-channel depletion MOS device. Other types of MOS devices are also possible.

[0053] In one embodiment, the semiconductor switch device 311 may include an IGBT device. For example, the semiconductor switch device 311 may include one or more of a level-shift drive IGBT device, an optocoupler isolation drive IGBT device, a capacitor isolation drive IGBT device, and an inductive isolation drive IGBT device. Other types of IGBT devices are also possible.

[0054] In one embodiment, the low-side driver LSD circuit 310 can be selected based on the magnitude of the discharge current generated by the induced voltage. The magnitude of the discharge current can affect the heat generation of the low-side driver LSD circuit 310 when it is turned on. For example, a higher discharge current may correspond to a higher-performance low-side driver LSD circuit 310, while a lower discharge current may correspond to a lower-performance low-side driver LSD circuit 310.

[0055] In one embodiment, the low-side driver LSD circuit 310 can be selected based on the required discharge duration of the discharge current generated by the induced voltage. The required discharge duration of the discharge current generated by the induced voltage can affect the heat generation of the low-side driver LSD circuit 310 when it is turned on. For example, when the magnitude of the discharge current is determined, a shorter discharge duration may mean that the low-side driver LSD circuit 310 needs to dissipate the energy corresponding to the induced voltage in the winding 222 in a shorter time, which requires the LSD circuit 310 to have higher electrical and heat dissipation performance; a longer discharge duration may mean that the low-side driver LSD circuit 310 can dissipate the energy corresponding to the induced voltage in the winding 222 in a longer time, which requires the LSD circuit 310 to have relatively lower electrical and heat dissipation performance.

[0056] FIG. 4 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure.

[0057] Components in FIG4 that are identical to those in FIG3 are not described again. The domain controller 230 in FIG4 also includes a microcontroller (MCU) 410. MCU 410 can be connected to the power supply 210 and the low-side driver (LSD) circuit 310. An MCU, also known as a single-chip microcomputer (MCU), is a microcomputer that integrates a central processing unit (CPU), memory, a timer / counter, and various input / output interfaces on a single integrated circuit chip.

[0058] The micro-control unit MCU 410 controlled by the domain controller 230 can be configured to send control signals to the power supply 210 and the low-side driver LSD circuit in response to user instructions. In one embodiment, in response to receiving an instruction from the user to cause the power supply 210 to supply power to the wiper motor 220, the micro-control unit MCU 410 can send a power control signal to the power supply 210 to instruct it to supply power. Simultaneously with or before sending the power control signal to the power supply 210 to instruct it to supply power, the micro-control unit MCU 410 can send an LSD control signal to the low-side driver LSD circuit 310 to instruct it to disconnect. In one embodiment, in response to receiving an instruction from the user to cause the power supply 210 to stop supplying power to the wiper motor 220, the micro-control unit MCU 410 can send a power control signal to the power supply 210 to instruct it to stop supplying power. Simultaneously with or after sending the power control signal to the power supply 210 to instruct it to disconnect, the micro-control unit MCU 410 can send an LSD control signal to the low-side driver LSD circuit 310 to instruct it to disconnect.

[0059] FIG. 5 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure.

[0060] Components identical to those in FIG. 4 are not described again in FIG. Although not shown, a voltage detection component may be connected between the microcontroller unit MCU 410 of the domain controller 230 and point P. This voltage detection component may be configured to detect the voltage at point P, which may represent the voltage outputted by the power supply 210, which is equipped with the low-side driver LSD circuit 310, to the wiper motor 220. The domain controller 230 in FIG. 5 may be configured, for example, via the microcontroller unit MCU 410, to monitor the voltage outputted by the power supply 210. When the domain controller 230 detects an abnormal voltage outputted by the power supply 210 via the microcontroller unit MCU 410, it may further diagnose the cause of the abnormality, such as a power supply failure or a failure of the low-side driver LSD circuit 310, by itself or in other ways.

[0061] The low-side driver LSD circuit 310 may include a diagnostic pin D. The diagnostic pin D may send a diagnostic signal to the micro-control unit 410 of the domain controller 230, indicating whether the low-side driver LSD circuit 310 is faulty. The micro-control unit MCU 410 of the domain controller 230 may determine whether the low-side driver LSD circuit 310 is faulty based on the diagnostic signal. The low-side driver LSD circuit 310 may send the diagnostic signal in response to a request from the micro-control unit MCU 410 of the domain controller 230. Alternatively, the low-side driver LSD circuit 310 may send the diagnostic signal periodically.

[0062] FIG. 6 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure.

[0063] Components in FIG. 6 that are identical to those in FIG. 3 are not described again. The discharge circuit in FIG. 6 also includes an LSD power supply 610. As shown in FIG. 6 , the LSD power supply 610 can be provided in the domain controller 230. The LSD power supply 610 can be configured to supply power to the LSD low-side driver (LSD) circuit 310 to implement the functions of the LSD low-side driver (LSD) circuit 310. The voltage of the LSD power supply 610 can be lower than the voltage of the power supply 210, and the two can be separate. The LSD power supply 610 can be configured to provide at least a portion of the control voltage that controls the on and off of the semiconductor switching device 311 and to power other operations of the LSD low-side driver (LSD) circuit 310, such as diagnostic operations of the LSD low-side driver (LSD) circuit 310. In one embodiment, the LSD low-side driver (LSD) circuit 310 can enter a sleep mode in response to a control signal indicating that the wipers are not enabled or in response to a control signal indicating that the low-side driver (LSD) circuit 310 enters a sleep mode. When the LSD low-side driver (LSD) circuit 310 enters the sleep mode, the LSD power supply 610 can disconnect from the LSD low-side driver (LSD) circuit 310, thereby stopping power supply to the low-side driver (LSD) circuit 310 to save power.

[0064] FIG. 7 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure.

[0065] Components identical to those in FIG. 6 are not described again in detail in FIG. The discharge circuit in FIG. 7 also includes a reverse polarity protection circuit 710. As shown in FIG. 7 , the reverse polarity protection circuit 710 can be provided in the domain controller 230. One end of the reverse polarity protection circuit 710 is connected to the low-side driver LSD circuit 310, and the other end is connected between the power supply 210 and the wiper motor 220. The reverse polarity protection circuit 710 can be configured to prevent a reverse polarity voltage from being generated in the low-side driver LSD circuit 310 and flowing to the power supply 210 if the LSD power supply 610 is mistakenly reversely connected to the low-side driver LSD circuit 310. The reverse polarity protection circuit 710 can be implemented in various ways. In one embodiment, the reverse polarity protection circuit 710 can be implemented using a unidirectionally conducting diode. In one embodiment, the reverse polarity protection circuit 710 can be implemented using a PMOS device. In another embodiment, the reverse polarity protection circuit 710 can be implemented using a combination of an NMOS device and a pump-up circuit.

[0066] FIG. 8 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure.

[0067] Components identical to those in FIG. 3 are not described again in FIG. The discharge circuit in FIG. 8 also includes an electrostatic discharge (ESD) protection circuit 810. As shown in FIG. 8 , the ESD protection circuit 810 can be provided in the domain controller 230. The ESD protection circuit 810 can be connected between the power supply 210 and the wiper motor 220. Electrostatic discharge from the wiper motor 220 or other components (not shown) can cause a reverse electrostatic discharge pulse to flow toward the power supply, potentially causing sudden or latent failure of the power supply. The ESD protection circuit 810 can include one or more of a transient suppressor diode (TVS), a multilayer varistor (MLV), a metal oxide varistor (MOV), a polymer ESD protection device, or a glass-ceramic ESD protection device. When a reverse electrostatic discharge pulse to flow toward the power supply is caused by the wiper motor 220 or other components (not shown), the ESD protection circuit 810 can operate to discharge the electrostatic discharge pulse, thereby protecting the power supply. In one embodiment, when an induced voltage is present in the winding to which power is de-energized due to electromagnetic induction, the ESD protection circuit 810 can reduce the induced voltage to a certain extent. Therefore, the ESD protection circuit 810 can also at least partially alleviate the adverse effects caused by the induced voltage.

[0068] Although Figures 4 to 8 respectively show that the discharge circuit includes a micro-control unit MCU 410, an LSD power supply 610, a reverse polarity protection circuit 710, and an ESD protection circuit 810, as those skilled in the art will understand, the discharge circuit may include one or more of the micro-control unit MCU 410, the LSD power supply 610, the reverse polarity protection circuit 710, and the ESD protection circuit 810 at the same time.

[0069] A domain controller (or regional controller) is the core of each functional domain in a vehicle. It primarily consists of three components: a domain master processor, an operating system, and application software and algorithms. Leveraging its high-performance domain master processor, extensive hardware interface resources, and robust software features, the domain controller can integrate core functions that would otherwise require multiple ECUs, significantly improving system integration. Furthermore, the standardized data exchange interface significantly reduces development and manufacturing costs. The discharge circuit described in this article can be applied to domain controllers or regional controllers.

[0070] FIG. 9 is a windshield wiper system according to an embodiment of the present disclosure.

[0071] The wiper system shown in FIG. 9 may include a battery module 910 , an inductive voltage release module 920 , a wiper module 930 and a domain controller 940 .

[0072] The power module 910 may be configured to provide power to the wiper module 930. The power module 910 may include a battery of the vehicle, such as a nickel-cadmium battery, a nickel-metal hydride battery, a lithium-ion battery, a polymer battery, a lead-acid battery, and the like.

[0073] The low-side driver LSD circuit 922 included in the inductive voltage release module 920 can be a low-side driver LSD circuit according to the description of FIG3-FIG8 or a combination thereof. As shown in FIG9 , the inductive voltage release module can be provided in the domain controller 940. When the domain controller 940 controls the power module 910 to supply power to the wiper module 930 normally, the low-side driver LSD circuit 922 included in the inductive voltage release module 920 can be controlled by the domain controller 940 to be turned off to maintain power delivery; when the domain controller 940 controls the power module 910 to stop supplying power to the wiper module 930, the low-side driver LSD circuit 922 can be controlled by the domain controller 940 to be turned on when the domain controller 940 controls the power module 910 to stop supplying power to the wiper module 930, thereby protecting the power module 910 from inductive damage and allowing the wiper 934 to stop at the user's desired position.

[0074] The wiper module 930 may include a wiper motor 932 and a wiper 934. The wiper motor 932 may be configured to drive the wiper 934 via windings 933 using power from the power module 910. The wiper motor 932 may include DC motors such as permanent magnet DC motors and electromagnetic DC motors, as well as AC motors such as synchronous AC motors and asynchronous AC motors. Although FIG9 shows a single winding 933, those skilled in the art will appreciate that the wiper motor 932 may include more windings to accommodate a wider range of wiper operating modes. Although FIG9 shows a single winding 933, those skilled in the art will appreciate that the wiper motor 932 may include more windings to accommodate a wider range of wiper operating modes. In one example, each of the multiple windings may correspond to a low-side driver (LSD) circuit 922. In another example, each of the windings may correspond to a low-side driver (LSD) circuit 922 only when the induced voltage generated in the winding is above a threshold. For example, windings with a number of turns exceeding a threshold may each correspond to a low-side driver LSD circuit 922 or only the winding with the highest number of turns may correspond to a low-side driver LSD circuit 922 .

[0075] The wipers 934 may include one or more of a bone wiper, a boneless wiper, and a composite wiper. The wipers 934 may be configured to be driven by a wiper motor 932 via a winding 933 to remove rain, snow, ice, washer fluid, water, or debris from the windshield.

[0076] The domain controller 940 can be the core of each functional domain of the vehicle. The domain controller 940 can be connected to the power module 910 and the wiper module 930. The domain controller 940 can control the power module 910 to supply power to the wiper motor 932 and control the conduction and disconnection of the low-side driver (LSD) circuit 922.

[0077] As shown in the wiper system of Figure 9, when the power module 910 is normally supplying power to the wiper module 930, the domain controller 940 controls the low-side driver (LSD) circuit 922 to shut down, resulting in minimal power consumption. When the domain controller 940 controls the power module 910 to stop supplying power to the wiper module 930, the domain controller 940 controls the low-side driver (LSD) circuit 922 to turn on, thereby protecting the power module 910. The low-side driver (LSD) circuit 922 can quickly direct the high current generated by the induced voltage in the winding 933 of the wiper motor 932 to ground, allowing the wiper 933 to stop at the user's desired position. The switch that turns the high current generated by the induced voltage on and off in the low-side driver (LSD) circuit 922 is a semiconductor switching device, eliminating arcing or sparking issues, significantly extending its service life. Furthermore, the low-side driver (LSD) circuit 922 can be controlled to turn on and off according to user instructions, providing greater flexibility.

[0078] Although the present disclosure has been described with exemplary embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims.

[0079] Any description in the present invention should not be construed as implying that any particular element, step, or function is essential to be included in the scope of the claims. The scope of the patented subject matter is limited only by the claims.

Claims

1. A discharge circuit for a vehicle wiper motor, in, The discharge circuit is arranged in a domain controller, the domain controller is configured to control a power supply to supply power to a wiper motor, the domain controller is connected to the power supply and the wiper motor, the power supply is configured to supply power to the wiper motor; The wiper motor includes a winding, and is configured to drive the wiper operation through the winding; Wherein, the discharge circuit comprises: A low-side drive LSD circuit, used for releasing the voltage induced in the winding, wherein a first end of the low-side drive LSD circuit is connected between a power supply and a winding of a wiper motor, and a second end of the low-side drive LSD circuit is connected to ground, wherein the low-side drive LSD circuit comprises a semiconductor switch device and a resistor connected in series between the power supply and ground, and the low-side drive LSD circuit is controlled to be turned on and off by the semiconductor switch device; Among them, when the domain controller controls the power supply to supply power to the wiper motor to drive the wiper operation, the low-side drive LSD circuit is controlled to be disconnected by the domain controller; when the domain controller controls the power supply to stop supplying power to the wiper motor, the low-side drive LSD circuit is controlled to be turned on by the domain controller to release the induced voltage in the winding.

2. The discharge circuit according to claim 1, wherein: The semiconductor switch device included in the low-side drive LSD circuit includes one or more of a MOS device and an IGBT device.

3. The discharge circuit according to claim 1, wherein: The low side drive LSD circuit is selected according to the size of the discharge current generated by the induced voltage and the discharge duration.

4. The discharge circuit according to claim 1, wherein: The resistor is at least used for current limiting.

5. The discharge circuit according to claim 1, wherein: The domain controller further comprises a micro control unit MCU, and the domain controller controls whether the power supply supplies power to the wiper motor and the on and off of the low side drive LSD circuit through the micro control unit MCU.

6. The discharge circuit according to claim 5, wherein: The domain controller also monitors, through the micro control unit MCU, a voltage outputted from a power supply to a wiper motor via the discharge circuit for a vehicle wiper motor.

7. The discharge circuit according to claim 5, wherein: The low-side driver LSD circuit includes a diagnostic pin, and wherein the domain controller further diagnoses whether the low-side driver LSD circuit is faulty through the micro-control unit MCU via the diagnostic pin of the low-side driver LSD circuit.

8. The discharge circuit according to claim 1, wherein: The low-side drive LSD circuit includes an LSD power supply, wherein the LSD power supply is configured to supply power for diagnostic operations of the low-side drive LSD circuit and to provide at least a portion of a control voltage for controlling the on and off of a semiconductor switching device, and the LSD power supply is turned off when the low-side drive LSD circuit is dormant.

9. The discharge circuit according to claim 8, further comprising a reverse polarity protection circuit, wherein: One end of the reverse polarity protection circuit is connected to the low-side drive LSD circuit, and the other end of the reverse polarity protection circuit is connected between the power supply and the wiper motor. The reverse polarity protection circuit is used to protect the power supply from the reverse polarity voltage generated by the low-side drive LSD circuit. 10 . The discharge circuit of claim 1 , further comprising an electrostatic discharge (ESD) protection circuit for at least partially reducing an induced voltage in the winding.

11. A domain controller comprising the discharge circuit according to any one of claims 1 to 10.

12. A motor vehicle comprising a discharge circuit according to any one of claims 1 to 10 and / or a domain controller according to claim 11.

13. A windshield wiper system, comprising: A windshield wiper module, the windshield wiper module comprising: A wiper motor, the motor comprising one or more windings, the motor being configured to use power from a power module to drive a wiper through the one or more windings, a wiper operably coupled to one of the one or more windings; a power module, wherein the power module is configured to supply power to the wiper module; An induced voltage release module, wherein the induced voltage release module is arranged in a domain controller, wherein the domain controller is configured to control the power supply module to supply power to the wiper module, wherein the domain controller is connected to the power supply module and the wiper module, wherein the induced voltage release module comprises at least one low-side drive LSD circuit, wherein the at least one low-side drive LSD circuit corresponds to one winding of one or more windings, wherein the low-side drive LSD circuit is used to release the voltage induced in the winding, wherein a first end of the low-side drive LSD circuit is connected between the power supply module and the winding of the wiper motor, and a second end of the low-side drive LSD circuit is connected to ground, Wherein, the low-side drive LSD circuit includes a semiconductor switch device and a resistor connected in series between the power module and the ground, and the low-side drive LSD circuit is controlled to be turned on and off by the semiconductor switch device; When the domain controller controls the power module to supply power to the wiper motor to drive the wiper operation, The low-side drive LSD circuit is controlled to be disconnected by the domain controller. When the domain controller controls the power supply module to stop supplying power to the wiper motor, the low-side drive LSD circuit is controlled to be turned on by the domain controller to release the induced voltage in the winding.

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