Wiper control method, wiper control device, and computer-readable recording medium

Abstract

A wiper control method, a wiper control apparatus, and a computer-readable recording medium are provided. The wiper control apparatus obtains an area of a pulse width modulation (PWM) control signal generated for driving a wiper motor while a wiper moves in a predefined section, and controls a speed of the wiper based on a result of comparing the area with at least one predefined reference value. Accordingly, damage to the wiper motor can be prevented.

Description

[0001] [Cross-reference to related applications]

[0002] This application is based on and claims priority over Korean Patent Application No. 10-2021-0081037, filed on June 22, 2021, with the Korean Intellectual Property Office, the full disclosure of which is incorporated herein by reference. Technical Field

[0003] One or more embodiments relate to a wiper control method and apparatus, and more specifically, to a wiper control method, apparatus, and computer-readable recording medium for controlling a wiper by identifying a load applied to a wiper motor. Background Technology

[0004] Wipers configured to wipe away raindrops by moving in a left-right direction are mounted on the windshield of a vehicle. An automatic wiper device is configured to automatically detect rainwater on the windshield and control the wiping speed based on the amount of rainwater. The wipers can also operate at a speed manually set by the user. The load applied to the wiper motor can vary depending on the friction between the windshield and the wiper, the wiper speed, etc., and the wiper motor may be damaged when an excessive load is applied. Therefore, to protect the wiper motor, it is necessary not only to simply control the wiper speed based on the amount of rainwater on the windshield, but also to consider the real-time load applied to the wiper motor. Summary of the Invention

[0005] The technical objective achieved by the embodiments of this disclosure is to provide a wiper control method and apparatus for preventing damage to the wiper motor by identifying the load applied to the wiper motor in real time without additional sensors.

[0006] Additional aspects will be set forth in part in the description which follows, and these aspects will become apparent in part from the description, or may be learned by practicing the embodiments presented in this disclosure.

[0007] According to one or more embodiments, a wiper control method implemented by a wiper control device includes: obtaining an area of ​​a pulse width modulation (PWM) control signal generated to drive a wiper motor while the wiper is moving in a predefined section; comparing the area with at least one predefined reference value; and controlling the speed of the wiper based on the result of comparing the area with the at least one predefined reference value.

[0008] According to one or more embodiments, a wiper control device includes: an area calculation unit configured to obtain an area of ​​a pulse width modulation (PWM) control signal generated to drive a wiper motor while the wiper is moving in a predefined section; a comparison unit configured to compare the area with at least one predefined reference value; and a control unit configured to control the speed of the wiper based on the result of comparing the area with the at least one predefined reference value. Attached Figure Description

[0009] The above and other aspects, features, and advantages of certain embodiments of this disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0010] Figure 1 This is a diagram of components of an example of a wiper drive device according to an embodiment.

[0011] Figure 2 This is a diagram illustrating an example of a pulse width modulation (PWM) control signal according to an embodiment.

[0012] Figure 3 This is a flowchart of an example of a wiper control method according to an embodiment.

[0013] Figure 4 This is a diagram illustrating an example of obtaining the area of ​​the PWM control signal according to an embodiment.

[0014] Figure 5 This is a diagram illustrating an example of a method for obtaining the area of ​​a PWM control signal generated in a wiper movement segment according to an embodiment.

[0015] Figure 6 This is a diagram of components of an example of a wiper control device according to an embodiment. Detailed Implementation

[0016] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein the same reference numerals refer to the same elements throughout. In this respect, the embodiments may take different forms and should not be considered as limited to the description set forth herein. Therefore, the embodiments are described below with reference to the figures only to illustrate various aspects of this description. The term "and / or" as used herein includes any and all combinations of one or more of the related listed items. Using expressions such as "at least one of" before the list of elements modifies the entire list of elements without modifying individual elements within the list.

[0017] The wiper control method and apparatus according to the embodiments will be described in detail below with reference to the accompanying drawings.

[0018] Figure 1This is a diagram of components of an example of a wiper drive device 100 according to an embodiment.

[0019] Reference Figure 1 The wiper drive unit 100 may include a micro-control unit (MCU) 110, a Hall sensor 120, and a motor driver 130. Additionally, the wiper drive unit 100 may also include various components, such as a connector 140 configured to receive power. However, for ease of explanation, this embodiment will be described primarily based on the components shown in the accompanying drawings.

[0020] Hall sensor 120 can identify the position of the wiper and provide the identified position to MCU 110. For example, Hall sensor 120 can identify whether the wiper is in a parked position or whether the wiper is in the lowest position (LRP) or highest position (URP) of the wiper's movement segment. According to the prior art, there are various methods for identifying the current position of the wiper, and Hall sensor 120 is not limited to its name and can be implemented according to various techniques for identifying the position of the wiper according to the prior art.

[0021] MCU 110 can generate a pulse width modulation (PWM) control signal for controlling the windshield wipers and provide the PWM control signal to motor driver 130. MCU 110 can use various methods according to existing technology to generate PWM control signals. For example, when the automatic windshield wipers operate automatically based on the amount of rain on the vehicle's windshield, MCU 110 can calculate the wiper speed based on information about the amount of rain received from an external device (e.g., a rain sensor, etc.) and generate a PWM control signal for controlling the calculated wiper speed. As another example, when the user manually inputs the wiper speed, MCU 110 can generate a PWM control signal for controlling the wipers with the manually input wiper speed. Methods for generating PWM control signals to control the speed of automatic or manual windshield wipers (i.e., methods implemented by MCU 110) are well known and will not be further elaborated upon.

[0022] Based on the PWM control signal provided from the MCU 110, the motor driver 130 can provide motor drive current to the wiper motor 150. The wiper motor 150 can have different rotational speeds depending on the amount of motor drive current, and therefore, the speed of the wipers connected to the wiper motor 150 can be controlled.

[0023] The MCU 110 can control the wiper motor 150 via feedback, allowing the wipers to move at a speed set automatically or manually. It is well known that the wiper speed can be configured to reach a predefined target speed by controlling the wiper motor via feedback using a PWM control signal, and therefore, its description is omitted. Furthermore, this embodiment can be implemented using various methods according to related technologies for controlling the wiper speed using a PWM control signal, and is not limited to the description herein.

[0024] To control the wipers to a target speed, the load applied to the wiper motor 150 can vary depending on various external environmental factors (such as the friction between the vehicle's windshield and the wipers, vehicle speed, impurities, etc.). For example, when the wipers move at speed A, the load applied to the wiper motor 150 in rainy weather may be different from the load applied to the wiper motor 150 in sunny weather.

[0025] As a method for identifying the load applied to the wiper motor 150, there may be methods using a current sensor that measures the amount of current transmitted to the wiper motor 150 and / or a temperature sensor that measures the temperature generated in the wiper motor 150. However, in this case, additional sensors are required, and therefore, the structure of the wiper drive unit 100 may become complex and the manufacturing cost may increase.

[0026] Therefore, according to this embodiment, a method is provided for identifying the load applied to the wiper motor 150 based on a PWM control signal generated by the MCU 110. Hereinafter, reference is first made to... Figure 2 This aspect will be explained in detail. Furthermore, the wiper control device according to the embodiment, which will be described below, can be implemented as follows: Figure 1 The wiper driver device 100 shown is part of the MCU 110, or is implemented to be connected to Figure 1 The MCU 110 shown is a standalone device. However, for ease of explanation, the following description will primarily focus on the implementation of the wiper control mechanism as follows: Figure 1 This shows a portion of the MCU 110.

[0027] Figure 2 This is a diagram illustrating an example of a PWM control signal according to an embodiment.

[0028] Reference Figure 2 The PWM control signal may include a pulse consisting of an on signal segment and an off signal segment, and may control the amount of motor drive current transmitted to the wiper motor 150 based on the length of the cycle T from the on signal segment to the pulse (i.e., the duty cycle).

[0029] Figure 3This is a flowchart of an example of a wiper control method according to an embodiment.

[0030] Reference Figure 3 The wiper control device can calculate the area of ​​the PWM control signal generated while the wiper is moving within a predefined section (S300). For example, the wiper control device can calculate the area of ​​the PWM control signal generated by the MCU while the wiper is moving from the lowest position to the highest position within the predefined section of the wiper. An example of calculating the area is... Figure 4 and Figure 5 As shown in the image.

[0031] The wiper control device can compare the area of ​​the PWM control signal with at least one predefined reference value (S310) and control the wiper speed based on the result of the comparison between the area of ​​the PWM control signal and the at least one predefined reference value (S320). For example, when only one reference value is defined, the wiper control device can assume that a large load is applied to the wiper motor when the area of ​​the PWM control signal is greater than the reference value, and the wiper control device can reduce the wiper speed by a predetermined value or rate (e.g., reduce it by 10% from the current speed), or change the wiper speed to a predetermined speed.

[0032] For example, in a scenario where the automatic wiper is controlled to have speed A based on rainfall, when the area of ​​the PWM control signal is greater than a reference value, the wiper control device can control the wiper to have speed B, which is lower than speed A. When the area of ​​the PWM control signal decreases to below the reference value, the wiper control device can stop the control intervention to restore the wiper speed to speed A. In other words, when the MCU 110 of the wiper driver device 100 controls the wiper speed using a conventional method and simultaneously receives a control command from the wiper control device, the MCU 110 can first process the command from the wiper control device.

[0033] Alternatively, the wiper control unit can identify a dry windshield when the area of ​​the PWM control signal is greater than a reference value, and can identify a wet windshield when the area of ​​the PWM control signal is equal to or less than the reference value. The wiper control unit can generate various control values. For example, the wiper control unit can provide external devices with a value regarding the identified windshield state, or it can use this value to control the wiper speed differently.

[0034] Figure 4 This is a diagram illustrating an example of obtaining the area of ​​the PWM control signal according to an embodiment.

[0035] Reference Figure 4Each pulse of the PWM control signal includes on signal segments 400 and 410 and an off signal segment. The wiper control device can obtain the area of ​​the PWM control signal by accumulating the areas of the on signal segments 400 and 410 of each pulse. For example, the wiper control device can obtain the area of ​​the on signal segments 400 and 410 of the pulse by using the frequency (i.e., pulse cycle T), the duty cycle of each pulse, and the amplitude (i.e., height Vo) of each pulse of the PWM control signal. When the pulse cycle T and the amplitude Vo of the PWM control signal are fixed values, the wiper control device can obtain the area of ​​each pulse by identifying only the duty cycle of each pulse.

[0036] Figure 5 This is a diagram illustrating an example of a method for obtaining the area of ​​a PWM control signal generated in a wiper movement segment according to an embodiment.

[0037] Reference Figure 5 The wiper control device can obtain the area of ​​the PWM control signal generated while the wiper is moving within a predefined section. According to this embodiment, for ease of explanation, it is shown that the area of ​​the PWM control signal generated while the wiper is moving from the lowest position LRP to the highest position URP is obtained. Figure 1 The example shown is of the area of ​​the PWM control signal generated by the MCU 110 of the wiper driver device 100. However, the predefined segment used to obtain the area of ​​the PWM control signal may be configured differently depending on the embodiment. For example, the predetermined segment may include a segment in which the wiper performs one reciprocating motion, a predetermined interval in which the wiper performs a uniform motion, or a predetermined angle segment.

[0038] When the number of pulses in the PWM control signal generated by MCU 110 is n as the wiper moves from the lowest position LRP to the highest position URP, the wiper control device can calculate the area of ​​the PWM control signal by accumulating the area of ​​the on signal segment of each pulse, as shown in the reference. Figure 4 As stated above.

[0039] According to another embodiment, the wiper control device can identify the duty cycle, etc., of the PWM control signal generated in a wiper movement segment (e.g., the segment from the lowest position to the highest position) based on a predetermined cycle Δt. Here, the cycle Δt for the duty cycle of the PWM control signal that the wiper control device can identify may be different from the pulse cycle T of the PWM control signal. For example, the cycle Δt for the duty cycle, etc., that the wiper control device can identify may be longer than the pulse cycle T of the PWM control signal. The wiper control device can set the duty cycles d1, d2... and dn of the PWM control signal (i.e., ...). Figure 4The area of ​​the corresponding pulse turn-on signal segment is accumulated (the duty cycle is identified for the corresponding cycle) to calculate the area of ​​the PWM control signal (S=d1+d2+...+dn).

[0040] When the wiper drive device 100 controls the wipers to operate at a uniform speed, the friction between the wipers and the windshield, etc., can change according to external environmental factors, and therefore, the load applied to the wiper motor can change. For example, due to friction, the duty cycle distribution 500 of the PWM control signal generated when the wipers are driven at speed A on a sunny day (i.e., when the windshield is dry) may differ from the duty cycle distribution 510 of the PWM control signal generated when the wipers are driven at speed A on a rainy day (i.e., when the windshield is wet). A >S B In other words, when the friction of the wipers increases, the MCU 110 may have to supply more current to the wiper motor by increasing the duty cycle of the PWM control signal to maintain speed A. However, when the friction of the wipers decreases, the MCU 110 can maintain speed A by supplying less current to the wiper motor by decreasing the duty cycle of the PWM control signal.

[0041] Figure 6 This is a diagram of components of an example of a wiper control device 600 according to an embodiment.

[0042] Reference Figure 6 The wiper control device 600 may include an area calculation unit 610, a comparison unit 620, and a control unit 630. Each component of the wiper control device 600 may be implemented as software, loaded into memory, and executed by a processor. For example, the wiper control device 600 according to this embodiment may be implemented as... Figure 1 A portion of the MCU 110 shown.

[0043] As the wiper moves within a predefined section, the area calculation unit 610 can obtain the area of ​​the PWM control signal generated to drive the wiper motor. An example of a method for obtaining the area of ​​the PWM control signal is shown in... Figure 4 and Figure 5 middle.

[0044] The comparison unit 620 can compare the area of ​​the PWM control signal with at least one predefined reference value.

[0045] The control unit 630 can control the speed of the wiper based on the result of a comparison between the area of ​​the PWM control signal and the at least one predefined reference value. For example, when multiple reference values ​​are defined, the control unit 630 can control the speed of the wiper differently according to the reference value among the multiple reference values ​​that corresponds to the area of ​​the PWM control signal.

[0046] This disclosure can also be implemented as computer-readable code in a computer-readable recording medium. Computer-readable recording media include all types of recording devices that store data readable by a computer system. Examples of computer-readable recording media include read-only memory (ROM), random-access memory (RAM), compact disk (CD)-ROM, solid-state drive (SSD) storage devices, optical data storage devices, etc. Computer-readable recording media can also be distributed across a network-coupled computer system, allowing computer-readable code to be stored and executed in a distributed manner.

[0047] As described above, according to one or more of the embodiments of this disclosure, damage to the wiper motor can be prevented by using software to identify the load applied to the wiper motor without adding additional hardware components. As another example, it is possible to identify whether the windshield is wet or dry.

[0048] It should be understood that the embodiments described herein are to be considered illustrative only and not for limiting purposes. The description of features or aspects within each embodiment should generally be considered applicable to other similar features or aspects in other embodiments. Although one or more embodiments have been described with reference to the figures, those skilled in the art will understand that various changes in form and detail may be made herein without departing from the spirit and scope defined by the foregoing claims.

Claims

1. A wiper control method implemented by a wiper control device, said wiper control device controlling the wiper by taking into account the load of the wiper motor that varies according to various external environmental factors, the wiper control method comprising: The wiper is controlled using a pulse width modulation control signal to achieve a predefined target speed; As the wiper moves between a lowest position and a highest position, the area is obtained by accumulating a pulse width modulation control signal on signal segment generated to drive the wiper motor, wherein the duty cycle of the pulse width modulation control signal varies between the lowest position and the highest position, and the on signal segment is obtained based on the amplitude and duty cycle of the pulse width modulation control signal. The area is compared with at least one predefined reference value; as well as The target speed of the wiper is changed based on the result of comparing the area with the at least one predefined reference value.

2. The wiper control method according to claim 1, wherein obtaining the area comprises obtaining the sum of the areas of each of the pulses of the pulse width modulation control signal by using the voltage, duty cycle, and cycle of the pulse width modulation control signal generated while the wiper is moving in a predefined section.

3. The wiper control method according to claim 1, wherein obtaining the area includes identifying the duty cycle of the pulse width modulation control signal for each predetermined time interval in a predefined segment and accumulating the pulse area obtained based on the duty cycle identified for each predetermined time interval.

4. The wiper control method according to claim 1, wherein comparing the area with the at least one predefined reference value includes identifying the windshield as dry when the area is greater than the at least one predefined reference value and identifying the windshield as wet when the area is equal to or less than the at least one predefined reference value.

5. The wiper control method according to claim 1, wherein changing the speed comprises: When the area is greater than the at least one predefined reference value, reduce the target speed of the wiper. When the area is lower than the at least one predefined reference value, the wiper speed is restored to the target speed.

6. A wiper control device, said wiper control device controlling the wiper by taking into account the load of the wiper motor that varies according to various external environmental factors, comprising: The control unit is configured to use a pulse width modulation control signal to control the wiper to achieve a predefined target speed; An area calculation unit is configured to obtain an area by accumulating on signal segments of multiple pulse width modulation control signals generated to drive the wiper motor while the wiper moves between a lowest position and a highest position, wherein the duty cycle of the pulse width modulation control signals varies between the lowest position and the highest position, and the on signal segments are obtained based on the amplitude and duty cycle of the pulse width modulation control signals. as well as The comparison unit is configured to compare the area with at least one predefined reference value; The control unit is configured to change the target speed of the wiper based on the result of comparing the area with the at least one predefined reference value.

7. The wiper control device according to claim 6, wherein the area calculation unit is further configured to identify the duty cycle of the pulse width modulation control signal for each predetermined time interval in a predefined segment and to accumulate the pulse area obtained based on the duty cycle identified for each predetermined time interval.

8. The wiper control device of claim 6, wherein the control unit is further configured to reduce the target speed of the wiper when the area is greater than the at least one predefined reference value, and to restore the speed of the wiper to the target speed when the area is less than the at least one predefined reference value.

9. The wiper control device of claim 6, wherein the control unit is further configured to identify that the windshield is in a dry state when the area is greater than the at least one predefined reference value and to identify that the windshield is in a wet state when the area is equal to or less than the at least one predefined reference value.

10. A computer-readable recording medium having a computer program recorded thereon for performing the method of claim 1.

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