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

Abstract

A discharge circuit for a wiper motor of a vehicle and a wiper system including the discharge circuit, the discharge circuit being disposed in a domain controller configured to control a power source to supply power to the wiper motor; the windshield wiper motor comprises a winding; the discharging circuit comprises a low-side driving LSD circuit used for releasing voltage induced in a winding, the first end of the LSD circuit is connected between a power source and the winding of the windshield wiper motor, the 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 between the power source and the ground in series, and the resistor is connected with the power source. When the domain controller controls the power supply to supply power to the wiper motor to drive the wiper to operate, the LSD circuit is controlled by the domain controller to be disconnected, and when the domain controller controls the power supply to stop supplying power to the wiper motor, the LSD circuit is switched off. The LSD circuit is controlled by the domain controller to be switched on so as to release the induced voltage in the winding. According to the discharge circuit, the induced voltage in the motor winding can be rapidly switched on and flows to the ground.

Description

Technical Field

[0001] The invention relates to an electronic circuit, in particular to a discharge circuit for a vehicle windshield 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 wipers are driven by a wiper motor with a winding. Users can start the wipers according to weather conditions or cleaning needs, and the wipers can be driven to swing repeatedly on the windshield for cleaning. After the wipers are finished using, the user can choose to stop supplying power to the wiper motor to end the wiper operation. However, after the wiper motor driving the wipers is powered off, there is still an induced voltage in the winding of the wiper motor. The induced voltage may have an adverse effect on the power supply circuit of the wipers, and at the same time bring an uncomfortable or unsafe user experience to the user. Summary of the invention

[0004] 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 the wiper operation through the winding; wherein the discharge circuit includes: a low-side drive LSD circuit, 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 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 supply and the ground, and the low-side drive LSD circuit is controlled to be turned on and off by the semiconductor switch 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.

[0005] 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.

[0006] 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.

[0007] According to the discharge circuit of the present disclosure, the resistor is at least used for current limiting.

[0008] According to the discharge circuit disclosed in the present invention, the domain controller further includes 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.

[0009] 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.

[0010] According to the discharge circuit disclosed in the present invention, the low-side drive LSD circuit includes a diagnostic pin, and the domain controller also diagnoses whether the low-side drive LSD circuit is faulty through the diagnostic pin of the low-side drive LSD circuit via the micro-control unit MCU.

[0011] According to the discharge circuit disclosed herein, 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.

[0012] According to the discharge circuit disclosed in the present invention, 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.

[0013] The discharge circuit according to the present disclosure further includes an electrostatic discharge (ESD) protection circuit, and the electrostatic discharge (ESD) protection circuit is used to at least partially reduce the induced voltage in the winding.

[0014] The present disclosure provides a domain controller, including the discharge circuit according to the present disclosure described above. The detailed features of the domain controller according to the present disclosure refer to the above description of the discharge circuit, which will not be repeated here for the sake of simplicity.

[0015] The present disclosure provides a motor vehicle, comprising the discharge circuit according to the present disclosure and / or the domain controller according to the present disclosure. The detailed features of the motor vehicle according to the present disclosure refer to the above description of the discharge circuit and the domain controller, which will not be repeated here for the sake of simplicity.

[0016] 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 arranged 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.

[0017] According to the discharge circuit and wiper system disclosed in the present invention, 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 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 arc or spark, so the number of uses or life 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

[0018] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description in conjunction with the accompanying drawings, in which:

[0019] Figure 1 It is a windshield wiper usage scenario;

[0020] Figure 2a It is a windshield wiper system;

[0021] Figure 2b It is another type of wiper system;

[0022] Figure 3 is a discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure;

[0023] Figure 4 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure;

[0024] Figure 5 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure;

[0025] Figure 6 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure;

[0026] Figure 7 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure;

[0027] Figure 8 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure.

[0028] Fig. 9 A windshield wiper system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0029] Before proceeding to the following detailed description, it may be advantageous to set forth definitions of certain words and phrases used throughout this disclosure. The terms "include" and "comprises" and their derivatives are meant to include, but are not limited to. The term "controller" or "control unit" refers to 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 local or remote. The phrase "at least one," 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 in the list may be required. For example, "at least one of A, B, C" includes any one of the following combinations: A, B, C, A and B, A and C, B and C, A and B and C.

[0030] 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.

[0031] The various embodiments of the principles of the present disclosure described below in conjunction with the accompanying drawings are only for illustration, and should not be interpreted as limiting the scope of the present disclosure in any way. It will be appreciated 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 different orders, and the desired results can still be achieved. In addition, the process depicted in the accompanying drawings does not necessarily require the specific order shown or the sequential order to achieve the desired results. In a specific embodiment, multitasking and parallel processing may be advantageous.

[0032] The text and drawings are provided as examples only to help understand the present disclosure. They should not be interpreted as limiting the scope of the claims attached to the present disclosure in any way. Although certain embodiments and examples have been provided, it is clear to those skilled in the art based on the content of the present disclosure that the embodiments and examples shown can be changed without departing from the scope of the present disclosure.

[0033] Figure 1 This is a windshield wiper usage scenario.

[0034] like Figure 1 The wiper usage scenario shown includes a windshield 110 and a wiper 120 .

[0035] The windshield 110 can be located at the front window or the rear window and other possible positions of the vehicle. For the purpose of clear vision, it is necessary to use a windshield wiper 120 to clean the windshield 110 .

[0036] The wiper 120 may be configured to be driven by a wiper motor to swing repeatedly to clean the windshield 110 .

[0037] Figure 2a It is a windshield wiper system.

[0038] like Figure 2a The wiper system shown may be installed in a variety of vehicles. Vehicles include, but are not limited to, cars, tractors (with or without trailers), buses, recreational vehicles, minivans or SUVs, construction equipment, agricultural equipment, aircraft, etc. Figure 2a As shown, the wiper system may include a power source 210 , a wiper motor 220 , and a wiper 120 .

[0039] 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, and the like.

[0040] The wiper motor 220 may be configured to receive an input voltage from the power source 210 and drive the wiper 120 to move through the winding 222. The wiper motor 220 may include a DC motor such as a permanent magnet DC motor and an electromagnetic DC motor, and an AC motor such as a synchronous AC motor and an asynchronous AC motor. Figure 2a As shown, the wiper motor 120 may include one winding 222, but those skilled in the art will appreciate that the wiper motor 220 may include more windings. For example, more windings with different numbers of turns may correspond to more speed modes.

[0041] The wiper 120 may include one or more of a bone wiper, a boneless wiper, and a composite wiper. The wiper 120 may be configured to be driven by a wiper motor 220 using a winding 222 to remove rain, snow, ice, washing liquid, water, or debris on the windshield.

[0042] Now refer to Figure 2a describe Figure 1 Wiper usage scenarios. Figure 1 In the scenario of the present invention, the user can start the wiper 120 according to the weather conditions or cleaning needs, and the wiper 120 can be driven to swing repeatedly on the windshield 110 for cleaning. After the use of the wiper 120 is over, the user can choose to stop supplying power to the wiper motor 220 to end the operation of the wiper 120. However, after the wiper motor 220 that drives the wiper 120 is stopped from being powered, the induced voltage still exists in the winding 222 of the wiper motor 220. For example, the user can instruct the power supply 110 to stop supplying power to the wiper motor 220 at time T1 to stop the operation of the wiper 120. However, due to the induced voltage still existing in the winding 222, the wiper 120 may continue to be driven to move and stop at time T3. The position where the wiper 120 finally stops at time T3 may not be what the user expects and may interfere with the user's field of vision. This brings an uncomfortable experience to the user and may pose a safety hazard. In addition, the induced voltage existing in the winding 222 may be of reverse polarity relative to the power supply voltage of the power supply 110, so there may be damage to the power supply 110.

[0043] Figure 2b It is another type of wiper system.

[0044] Figure 2b Zhongyu Figure 2a The same components will not be described repeatedly. Figure 2b The wiper system in the embodiment further includes a transient voltage suppression diode (TVS) diode or a Zener diode 230 .

[0045] Now refer to Figure 2b describe Figure 1Wiper usage scenarios. Figure 1 In the scenario, after the wiper motor 220 driving the wiper 120 is powered off, there is still an induced voltage in the winding 222 of the wiper motor 220. For example, the user can instruct the power supply 110 to stop supplying power to the wiper motor 220 at time T1 to stop the operation of the wiper 120. However, due to the induced voltage still existing in the winding 222, the wiper 120 may continue to be driven to move. At this time, the TVS diode or the Zener diode 230 may act and release the induced voltage in the winding 222 of the wiper motor 220. However, the induced voltage in the winding 222 is large, and the ability of the TVS diode or the Zener diode 230 to release the induced voltage is limited, resulting in a slow release speed of the induced voltage. Therefore, the wiper 120 may stop at T2, which is slightly shorter than T3. The position where the wiper 120 finally stops at time T2 may still not be what the user expects, and may interfere with the user's field of view. This brings an uncomfortable experience to the user and may pose a safety hazard. In addition, the induced voltage in the winding 222 may be of reverse polarity relative to the supply voltage of the power supply 110, so there may still be damage to the power supply 110. In addition, the TVS diode or the Zener diode 230 is not controlled by the user and will only act when the induced voltage value reaches its threshold, so the flexibility is poor.

[0046] Figure 3 A discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure.

[0047] Figure 3 Zhongyu Figure 2a The same components will not be described repeatedly. Figure 3 The discharge circuit further includes a low side driver LSD circuit 310 and a domain controller 230. Figure 3 As shown, the low-side driver LSD circuit 310 is provided in the domain controller 230. The low-side driver LSD circuit 310 in the domain controller 230 can be used to release the voltage induced in the winding. Figure 3 As shown, the first end of the low-side drive LSD circuit 310 is connected between the power supply and the winding of the wiper motor, and the second end of the low-side drive LSD circuit is connected to the ground. The domain controller or regional controller 230 can be the core of each functional domain of the car. Relying on the high-performance domain master processor, rich hardware interface resources and powerful software functional characteristics, the domain controller can integrate the core functions that originally require many automobile control units ECU to implement, greatly improving the system function integration, coupled with the standardized interface of data interaction, so it can greatly reduce the development and manufacturing costs of this part. The domain controller 230 can be connected to the power supply 210 and the wiper motor 220. The domain controller 230 can control the power supply 210 to supply power to the wiper motor 220, and control the conduction and disconnection of the low-side drive LSD circuit 310.

[0048] The low side driver LSD circuit 310 may include a semiconductor switch device 311 and a resistor 322 connected in series between a power supply and a ground. Figure 3 As shown, 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 the resistor 312, and the other end of the resistor 312 can be connected to the ground, and 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 are not described in detail herein. The low-side drive LSD circuit 310 can receive an LSD control signal (not shown in the figure) 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.

[0049] 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 drive LSD circuit may receive an LSD control signal indicating disconnection from the domain controller 230. The LSD control signal sent by the domain controller 230 may be associated with a user's indication of whether the power supply 210 supplies power to the wiper motor 220. In response to the control signal indicating disconnection, the low-side drive LSD circuit may be controlled to be disconnected through the semiconductor switch device 311. At this time, the low-side drive LSD circuit 310 does not affect the power supply of the power supply 210 to the wiper motor 220.

[0050] 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 drive LSD circuit may receive a control signal indicating conduction from the domain controller 230. In response to the control signal indicating conduction, the low-side drive LSD circuit may be controlled to be turned on through the semiconductor switch device 311. At this time, the large current generated by the induced voltage in the winding 222 in the wiper motor 220 may be quickly conducted to the ground through the low-side drive LSD circuit 310. Figure 1In the example scenario, the position where the wiper 120 finally stops can be almost the same as the position where the wiper 120 is at time T1 when the user indicates to stop supplying power to the wiper motor 220. Therefore, the user can control the wiper 120 to stop at the position desired by the user. And because the induced voltage in the winding 222 of the wiper motor 220 is quickly released, the power supply 210 can be protected from damage. In addition, since the low-side drive circuit LSD turns on and off the large current generated by the induced voltage through the semiconductor switching device 311, there is no problem of arc or spark of the electromagnetic relay or the traditional mechanical switch, so the number of uses or life of the low-side drive circuit LSD is significantly more. In addition, the discharge circuit can be turned on and off in a controlled manner according to the control signal indicated by the user, so the flexibility is better.

[0051] 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.

[0052] 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 inductor isolation drive IGBT device. Other types of IGBT devices are also possible.

[0053] In one embodiment, the low-side driver LSD circuit 310 can be selected according to the size of the discharge current generated by the induced voltage. The size of the discharge current can affect the heating condition 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, and a lower discharge current may correspond to a lower performance low-side driver LSD circuit 310.

[0054] In one embodiment, the low-side drive LSD circuit 310 can be selected according to 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 heating of the low-side drive LSD circuit 310 when it is turned on. For example, in the case of determining the size of the discharge current, a shorter discharge duration may mean that the low-side drive 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 drive 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 low electrical and heat dissipation performance.

[0055] Figure 4 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure.

[0056] Figure 4 Zhongyu Figure 3 The same components will not be described repeatedly. Figure 4 The domain controller 230 included in the embodiment also includes a microcontroller unit (MCU) 410. The microcontroller unit MCU 410 can be connected to the power supply 210 and the low-side driver LSD circuit 310. The microcontroller unit MCU is also called a single-chip microcomputer, which is a microcomputer that integrates a central processing unit, a memory, a timer / counter, various input and output interfaces, etc. on an integrated circuit chip.

[0057] The micro-control unit MCU 410 controlled by the domain controller 230 may be configured to send control signals to the power supply 210 and the low-side drive LSD circuit respectively in response to user instructions. In one embodiment, in response to receiving an instruction from the user to make the power supply 210 supply power to the wiper motor 220, the micro-control unit MCU 410 may send a power control signal indicating power supply to the power supply 210. At the same time or before sending the power control signal indicating power supply to the power supply 210, the micro-control unit MCU 410 may send an LSD control signal indicating that the low-side drive LSD circuit 310 is disconnected to the low-side drive LSD circuit 310. In one embodiment, in response to receiving an instruction from the user to make the power supply 210 stop supplying power to the wiper motor 220, the micro-control unit MCU 410 may send a power control signal indicating that the power supply 210 stops supplying power to the wiper motor 220. At the same time or after sending the power control signal indicating that the power supply stops supplying power to the power supply 210, the micro-control unit MCU 410 may send an LSD control signal indicating that the low-side drive LSD circuit 310 is turned on to the low-side drive LSD circuit 310.

[0058] Figure 5is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure.

[0059] Figure 5 Zhongyu Figure 4 The same components are not described again. Although not shown, a voltage detection component may be connected between the micro-control unit MCU410 of the domain controller 230 and point P. The voltage detection component may be configured to detect a voltage at point P, which may represent a voltage outputted from the power supply 210 configured with the low-side drive LSD circuit 310 to the wiper motor 220. Figure 5 The domain controller 230 in the embodiment can be configured to monitor the voltage output by the power supply 210, for example, through the micro-control unit MCU 410. When the domain controller 230 monitors that the voltage output by the power supply 210 is abnormal through the micro-control unit MCU 410, the abnormal cause can be further diagnosed by itself or in other ways, for example, a power failure or a low-side driver LSD circuit 310 failure, etc.

[0060] The low-side driver LSD circuit 310 may include a diagnostic pin D. The diagnostic pin D may send a diagnostic signal indicating whether the low-side driver LSD circuit 310 is faulty to the micro-control unit 410 of the domain controller 230. 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 a diagnostic signal in response to a request from the micro-control unit MCU 410 of the domain controller 230, or alternatively, the low-side driver LSD circuit 310 may send a diagnostic signal periodically.

[0061] Figure 6 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure.

[0062] Figure 6 Zhongyu Figure 3 The same components will not be described repeatedly. Figure 6 The discharge circuit also includes an LSD power supply 610. Figure 6As shown, the LSD power supply 610 can be arranged in the domain controller 230. The LSD power supply 610 can be configured to supply power to the LSD low-side drive LSD circuit 310 to realize the function of the low-side drive LSD circuit 310. The voltage of the LSD power supply 610 can be smaller than the voltage of the power supply 210, and the two can be separated. The LSD power supply 610 can be configured to provide at least a portion of the control voltage that controls the semiconductor switch device 311 to be turned on and off and to supply power to other operations of the low-side drive LSD circuit 310, for example, the diagnostic operation of the low-side drive LSD circuit 310. In one embodiment, the low-side drive LSD circuit 310 can enter the sleep mode in response to a control signal that the wiper is not enabled or in response to a control signal indicating that the sleep mode is entered. When the low-side drive LSD circuit 310 enters the sleep mode, the LSD power supply 610 can disconnect the connection with the low-side drive LSD circuit 310, thereby stopping supplying power to it to save power.

[0063] Figure 7 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure.

[0064] Figure 7 Zhongyu Figure 6 The same components will not be described repeatedly. Figure 7 The discharge circuit also includes a reverse polarity protection circuit 710. Figure 7 As shown, the reverse polarity protection circuit 710 can be set in the domain controller 230. One end of the reverse polarity protection circuit 710 is connected to the low-side drive LSD circuit 310, and the other end of the reverse polarity protection circuit 710 is connected between the power supply 210 and the wiper motor 220. The reverse polarity protection circuit 710 can be configured to prevent the reverse polarity voltage flowing to the power supply 210 from being generated in the low-side drive LSD circuit 310 when the LSD power supply 610 is mistakenly reversely connected to the low-side drive 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 by a unidirectionally conducting diode. In one embodiment, the reverse polarity protection circuit 710 can be implemented by a PMOS device. In one embodiment, the reverse polarity protection circuit 710 can be implemented by a combination of an NMOS device and a pump-up circuit.

[0065] Figure 8 is another discharge circuit for a vehicle wiper motor according to an embodiment of the present disclosure.

[0066] Figure 8 Zhongyu Figure 3 The same components will not be described repeatedly. Figure 8 The discharge circuit also includes an electrostatic discharge (ESD) protection circuit 810. Figure 8As shown, an electrostatic discharge (ESD) protection circuit 810 may be provided in the domain controller 230. The electrostatic discharge (ESD) protection circuit 810 may be connected between the power supply 210 and the wiper motor 220. The electrostatic discharge of the wiper motor 220 or other components not shown may cause a reverse electrostatic discharge pulse to flow to the power supply, which may cause a sudden failure or potential failure of the power supply. The ESD protection circuit 810 may include one or more of a transient suppression diode TVS tube, a multilayer varistor MLV, a metal oxide varistor MOV, a polymer ESD protection device, and a glass ceramic ESD protection device. When a reverse electrostatic discharge pulse flows to the power supply due to the wiper motor 220 or other components not shown, the ESD protection circuit 810 may act to discharge the electrostatic discharge pulse to protect the power supply. In one embodiment, when the winding to which power supply is stopped has an induced voltage due to electromagnetic induction therein, the ESD protection circuit 810 may reduce the induced voltage to a certain extent. Therefore, the ESD protection circuit 810 may also at least partially alleviate the adverse effects caused by the induced voltage.

[0067] although Figure 4-Figure 8 The discharge circuit is shown to include a micro-control unit MCU 410, an LSD power supply 610, a reverse polarity protection circuit 710, and an ESD protection circuit 810, respectively. However, as will be understood by those skilled in the art, 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.

[0068] The domain controller or regional controller is the core of each functional domain of the car. It is mainly composed of three parts: domain master processor, operating system, and application software and algorithms. Relying on high-performance domain master processor, rich hardware interface resources and powerful software functional characteristics, the domain controller can integrate the core functions that originally require many automotive control units ECU to implement, greatly improving the system function integration, coupled with the standardized interface for data interaction, it can greatly reduce the development and manufacturing costs of this part. The discharge circuit described in this article can be used in a domain controller or regional controller.

[0069] Fig. 9 A windshield wiper system according to an embodiment of the present disclosure.

[0070] according to Fig. 9 The wiper system shown may include a battery module 910 , an inductive voltage release module 920 , a wiper module 930 , and a domain controller 940 .

[0071] 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.

[0072] The low side drive LSD circuit 922 included in the inductive voltage release module 920 may be based on Figure 3-Figure 8 The low side drive LSD circuit described in or a combination thereof. Fig. 9 As shown, the inductive voltage release module can be set in the domain controller 940. The low-side drive 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 supply power to the wiper module 930 normally; 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 power module 910 to be turned on, thereby protecting the power module 910 from inductive damage and making the wiper 934 stop at the position desired by the user.

[0073] 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 to move through the power from the power module 910 and through the winding 933. The wiper motor 932 may include a DC motor such as a permanent magnet DC motor and an electromagnetic DC motor, and an AC motor such as a synchronous AC motor and an asynchronous AC motor. Fig. 9 One winding 933 is shown in the figure, but those skilled in the art will appreciate that the wiper motor 932 may include more windings to correspond to more wiper operation modes. Fig. 9 One winding 933 is shown in the figure, but those skilled in the art will understand that the wiper motor 932 may include more windings to correspond to more wiper operation modes. In one example, more windings may each correspond to a low-side drive LSD circuit 922. In another example, only when the induced voltage generated in the winding is higher than the threshold, these windings may each correspond to a low-side drive LSD circuit 922. For example, the windings with more than a threshold number of turns may each correspond to a low-side drive LSD circuit 922 or only the winding with the highest number of turns may correspond to a low-side drive LSD circuit 922.

[0074] The wiper 934 may include one or more of a bone wiper, a boneless wiper, and a composite wiper. The wiper 934 may be configured to be driven by a wiper motor 932 through a winding 933 to remove rain, snow, ice, washing liquid, water, or debris on the windshield.

[0075] The domain controller 940 may be the core of each functional domain of the automobile. The domain controller 940 may be connected to the power module 910 and the wiper module 930. The domain controller 940 may control the power module 910 to supply power to the wiper motor 932, and control the on and off of the low side drive LSD circuit 922.

[0076] like Fig. 9 In the wiper system shown, when the power module 910 normally supplies power to the wiper module 930, the domain controller 940 controls the low-side drive LSD circuit 922 to turn off, and the power consumption generated is extremely small. 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 drive LSD circuit 922 to turn on, so the power module 910 is protected. The low-side drive LSD circuit 922 can quickly guide the large current generated by the induced voltage in the winding 933 of the wiper motor 932 to the ground, so the wiper 933 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 low-side drive LSD circuit 922 is a semiconductor switch device, and there is no problem of arc or electric spark, so the number of uses or life is significantly more. In addition, the low-side drive LSD circuit 922 can be turned on and off in a controlled manner according to user instructions, so it is more flexible.

[0077] Although the present disclosure has been described with exemplary embodiments, various changes and modifications may be suggested to one skilled in the art. The present disclosure is intended to encompass such changes and modifications as fall within the scope of the appended claims.

[0078] Any description in the present invention should not be construed as implying that any particular element, step, or function is an essential element that must be included in the claims scope. The scope of the patented subject matter is limited solely 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; Among them, when the domain controller controls the power supply 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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