JP2008114684A - Wiper device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiper device easily specifying factors for a change when the change occurs in a load of a motor for reciprocating a wiper blade. <P>SOLUTION: A fluctuation pattern detected by a fluctuation pattern detection unit 22 is compared with a reference pattern stored in a reference pattern storage unit 24 by a pattern comparison unit 26, and a factor of a change when a fluctuation state of a load on a motor 12 is changed from a fluctuation state indicated by the reference pattern, is specified based on the result of comparison by the pattern comparison unit 26. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wiper device, and more particularly to a wiper device that reciprocates a wiper blade to wipe away raindrops attached to a contact surface with which the wiper blade contacts.

  2. Description of the Related Art Conventionally, vehicles such as automobiles have been provided with a wiper device in order to prevent the field of view from being lowered due to raindrops attached to the windshield when it rains. This wiper device wipes raindrops adhering to the windshield by reciprocating a wiper blade. The driver controls the operation speed and interval of the wiper blade by switching the operation changeover switch of the wiper device according to the rainfall.

  By the way, the amount of raindrops that hit the windshield of a vehicle that travels during raining varies not only with the influence of the rainfall, but also with the traveling speed of the vehicle. For this reason, in order to maintain the optimal state of view in urban areas where the traveling speed changes frequently, the driver must frequently perform switching operation of the operation changeover switch, and the operation is complicated. there were.

  As a technique for solving this problem, Patent Document 1 discloses that a wiper blade is 1 by making use of the fact that the load of a motor for reciprocating the wiper blade changes according to the amount of raindrops attached to the windshield. A technique is disclosed in which the load of the motor is detected from the reciprocation time of the reciprocation, the amount of raindrops adhering to the windshield is obtained from the detected motor load, and the operation speed and interval of the wiper blade are controlled according to the amount of raindrops. Yes.

Further, in Patent Document 2, for example, when a wiper blade is reciprocated in a vehicle that is operating at high speed on a highway or the like, a forward path when the wiper blade reciprocates due to wind hitting the windshield is disclosed. In order to eliminate the feeling that the driver feels strange due to a difference in the speed of the return path, the current value of the motor when the predetermined time has elapsed from the start of the forward path operation when the wiper blade is reciprocated and the return path operation The motor load in the forward path and the return path is detected from the energized current value of the motor when a predetermined time has elapsed from the start, and different voltages are applied to the motor during the forward path operation and the backward path operation of the wiper blade based on the motor load. A technique for controlling in this way is disclosed.
JP 7-137606 A Japanese Patent Laid-Open No. 2003-40087

  By the way, in the wiper device, the reciprocation time for which the wiper blade makes one reciprocation varies depending on the state of the windshield such as the amount of raindrops attached to the windshield, dirt (for example, sand), temperature, and humidity.

  Further, in the wiper device, the reciprocation time for which the wiper blade makes one reciprocation may change depending on the wind hitting the windshield.

  For this reason, in the case where the technique disclosed in Patent Document 1 is applied to detect the load of the motor from the change in the reciprocating time, and the amount of raindrops is obtained from the detected motor load, the load of the motor that causes the wiper blade to reciprocate There is a problem that it is not possible to determine whether the windshield has changed due to the windshield state such as raindrops attached to the windshield or the windshield hitting the windshield.

  For this reason, in the technique disclosed in Patent Document 1, for example, when the round trip time changes due to wind hitting the windshield, it is assumed that the amount of raindrops attached to the windshield has changed. The operating speed and interval may change.

  The technique disclosed in Patent Document 2 is a technique for reducing the difference in operation speed between the forward path and the return path of the wiper blade, and is not a technique for identifying the cause of the change from a change in the motor load.

  The present invention has been made to solve the above-described problems, and provides a wiper device that can easily identify a factor of a change in a load of a motor that reciprocates a wiper blade. For the purpose.

  In order to achieve the above object, the invention according to claim 1 is directed to a motor that reciprocates the wiper blade, and detection that detects a variation pattern indicating a variation state of a load on the motor when the wiper blade is reciprocated. Storage means for previously storing, as a reference pattern, the fluctuation pattern when the wiper blade is reciprocated with a predetermined external factor with respect to the contact surface with which the wiper blade contacts when reciprocating; Comparison means for comparing the fluctuation pattern detected by the detection means with a reference pattern stored in the storage means, and a fluctuation state in which the fluctuation state of the load on the motor is indicated by the reference pattern based on the comparison result by the comparison means And a specifying means for specifying a factor of the change when the change occurs.

  According to the first aspect of the present invention, the detecting means detects the fluctuation pattern indicating the fluctuation state of the load on the motor when the wiper blade is reciprocated, while the storage means detects the wiper blade when reciprocating. The fluctuation pattern when the wiper blade is reciprocated with the external factor with respect to the contact surface contacting with a predetermined state is stored in advance as a reference pattern.

  Here, in the present invention, the fluctuation pattern detected by the detection means is compared with the reference pattern stored in the storage means by the comparison means, and the fluctuation state of the load on the motor based on the comparison result by the comparison means is determined by the specifying means. When the change occurs from the fluctuation state indicated by the reference pattern, the factor of the change is specified.

  As described above, according to the first aspect of the present invention, the fluctuation pattern when the wiper blade is reciprocated with the external factor with respect to the contact surface with which the wiper blade contacts during the reciprocating operation being a predetermined state is stored as the reference pattern. Is stored in advance, a fluctuation pattern indicating a fluctuation state of the load on the motor when the wiper blade is reciprocated is detected, the detected fluctuation pattern is compared with a reference pattern stored in the storage means, and the comparison is performed. Based on the result, the load change state for the motor is changed when the change state occurs from the change state indicated by the reference pattern. Therefore, the load of the motor for reciprocating the wiper blade has changed. It is possible to easily identify the cause of the change in the case.

  In the present invention, as in the invention described in claim 2, the predetermined state may be a state in which a predetermined amount of water droplets are attached to the contact surface and the wind on the contact surface is no wind.

  According to the present invention, as in the third aspect of the invention, the detection means detects a variation pattern for each of the forward path and the return path when the wiper blade is reciprocated, and the storage means May be stored in advance for each of the forward path and the return path when the wiper blade is reciprocated, and the comparison unit may compare the variation pattern with the reference pattern for each of the forward path and the return path.

  According to a fourth aspect of the present invention, the detecting means detects the current value of the current supplied to the motor or the fluctuation state of the rotational speed of the motor when the wiper blade is reciprocated as in the fourth aspect. By doing so, you may detect the fluctuation pattern which shows the fluctuation state of the load of the said motor.

  Further, as in the invention according to claim 5, the comparing means of the present invention calculates the average value of the load fluctuation state indicated by the fluctuation pattern of the load fluctuation state indicated by the reference pattern stored in the storage means. The variation pattern may be compared with the reference pattern by comparing with an average value.

  Further, according to the present invention, as in the invention described in claim 6, the storage means temporarily stores at least a predetermined number of variation patterns detected by the detection means in order from the most recently detected pattern, The comparison means compares the fluctuation pattern detected by the detection means with the reference pattern stored in the storage means and the fluctuation pattern retroactive to the predetermined number from the fluctuation pattern stored in the storage means, and the comparison means Detection means for detecting an abrupt change in load on the motor based on the comparison result may be further provided.

  On the other hand, in order to achieve the above object, the invention according to claim 7 detects a fluctuation pattern indicating a fluctuation state of a load applied to the motor that reciprocates the wiper blade and the motor when the wiper blade is reciprocated. Detection means; storage means for temporarily storing at least a predetermined number of variation patterns detected by the detection means in order from the most recently detected one; and storing the variation patterns detected by the detection means in the storage means Comparison means for comparing with the fluctuation pattern that is traced back by the predetermined number from the fluctuation pattern, and detection means for detecting sudden fluctuations in the load on the motor based on the comparison result by the comparison means.

  According to the seventh aspect of the present invention, the detection means detects a fluctuation pattern indicating a fluctuation state of the load on the motor when the wiper blade is reciprocated, and the storage means detects the fluctuation pattern detected by the detection means. At least a predetermined number is temporarily stored in order from the most recently detected one.

  Here, in the present invention, the comparison unit compares the variation pattern detected by the detection unit with a variation pattern retroactive to the variation pattern stored in the storage unit, and the detection unit compares the variation pattern detected by the comparison unit. Based on this, sudden fluctuations in the load on the motor are detected.

  Thus, according to the seventh aspect of the present invention, the fluctuation pattern indicating the fluctuation state of the load on the motor when the wiper blade is reciprocated is detected, and the detected fluctuation pattern is at least sequentially from the most recently detected one. A predetermined number is temporarily stored in the storage means, and the detected fluctuation pattern is compared with a fluctuation pattern that is a predetermined number backward from the fluctuation pattern stored in the storage means, and a sudden load on the motor is suddenly determined based on the comparison result. Since the change is detected, it is possible to detect that the load of the motor has changed suddenly.

  As described above, according to the present invention, the fluctuation pattern when the wiper blade is reciprocated with the external factor with respect to the contact surface with which the wiper blade contacts during the reciprocating operation being a predetermined state is stored in advance by the storage means as the reference pattern. In addition, a fluctuation pattern indicating a fluctuation state of the load on the motor when the wiper blade is reciprocated is detected, and the detected fluctuation pattern is compared with a reference pattern stored in the storage unit, and based on the comparison result. Since the cause of the change when the change state of the load on the motor changes from the change state indicated by the reference pattern is specified, the change of the load of the motor that causes the wiper blade to reciprocate is detected. The effect that the factor of change can be specified easily is acquired.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 shows a configuration of a wiper device 10 according to the present embodiment. Hereinafter, the case where the present invention is applied to a wiper device that is mounted on a vehicle and wipes raindrops attached to a windshield by reciprocating a wiper blade will be described.

  As shown in the figure, the wiper device 10 has a wiper blade 11 for wiping raindrops adhering to the windshield, a motor 12 for reciprocating the wiper blade 11, and a motor 12 for reciprocating the wiper blade 11. And a microcomputer (hereinafter referred to as a “microcomputer”) 14 that detects a fluctuation pattern indicating a fluctuation state of the load and outputs a drive control signal for controlling the rotation speed of the motor 12 based on the detection result. .

  The motor 12 drives the wiper blade 11 in a reciprocating manner by driving at a rotational speed corresponding to the drive control signal input from the microcomputer 14. The motor 12 is provided with a rotary encoder 16. The rotary encoder 16 outputs a pulse signal having a period corresponding to the rotation speed of the motor 12 to the microcomputer 14.

  The microcomputer 14 includes a CPU (central processing unit), a ROM, and a RAM, and a drive control program (see also FIG. 4), a reference pattern, and the like described later are stored in advance in the ROM. Yes.

  By the way, in the wiper apparatus 10, when raindrops adhere to the windshield, the load on the motor 12 when the wiper blade 11 is reciprocated is smaller than when no raindrops adhere, so the rotational speed of the motor 12 is reduced. Get faster.

  FIG. 2 shows fluctuations in the rotational speed of the motor 12 in the forward path and the return path when the wiper blade 11 is reciprocated in the wet state where raindrops are attached to the windshield and in the dry state where no raindrops are attached. An example of the state is shown. The horizontal axis indicates the numerical value of 1 to 10 in ascending order from one end side to the boundary point of one end, the other end, and the divided area of the operation range when the operation range when the wiper blade 11 reciprocates is divided into nine equal parts. The wiping position within the operation range of the wiper blade 11 is shown in correspondence with FIG.

  Further, in the wiper device 10, when the wind is hitting the windshield, the fluctuation state of the load on the motor 12 is different between the forward path and the return path when the wiper blade 11 is reciprocated. The fluctuation state of is different.

  Therefore, the microcomputer 14 detects a variation pattern indicating a variation state of the load on the motor 12 when the wiper blade 11 is reciprocated, compares the detected variation pattern with a reference pattern, and based on the comparison result, the wiper blade 11. When the motor is reciprocated, a factor causing a change in the load of the motor 12 is specified, and a control drive control signal corresponding to the specified factor is output. In the present embodiment, the fluctuation pattern shows a fluctuation state of the rotational speed of the motor 12 in the forward path and the return path when the wiper blade 11 is reciprocated based on the pulse signal input from the rotary encoder 16. Detect fluctuation patterns.

  On the other hand, FIG. 3 shows a functional block diagram showing a functional configuration of the microcomputer 14 according to the present embodiment.

  The microcomputer 14 detects the fluctuation pattern indicating the fluctuation state of the rotational speed of the motor 12 when the wiper blade 11 is reciprocated based on the pulse signal input from the rotary encoder 16, and the reference. A reference pattern storage unit 24 that stores patterns in advance, a pattern comparison unit 26 that compares a variation pattern detected by the variation pattern detection unit 22 with a reference pattern stored in the reference pattern storage unit 24, and a comparison by the pattern comparison unit 26 Based on the result, when the change state of the load on the motor 12 changes from the change state in the reference pattern, the change factor specifying unit 28 for specifying the factor of the change and the factor specified by the change factor specifying unit 28 Motor drive control unit 3 for outputting a drive control signal for controlling the drive of the motor 12 It is equipped with a door.

  The reference pattern storage unit 24 according to the present embodiment attaches a predetermined amount of water droplets to the contact surface of the windshield that the wiper blade 11 contacts when the wiper blade 11 reciprocates and winds the contact surface. A variation pattern indicating a variation state of the rotational speed of the motor 12 in the forward path and the backward path as shown in FIG. 2 when the wiper blade 11 is reciprocated in a windless state is stored in advance separately as a reference pattern. Yes.

  In addition, the pattern comparison unit 26 according to the present embodiment stores the average values of the rotational speed fluctuation states indicated by the detected forward and backward fluctuation patterns in the reference pattern storage unit 24 for each of the forward and backward paths. It compares with the average value of the fluctuation state of the rotational speed shown by the made reference pattern.

  Further, the change factor specifying unit 28 according to the present embodiment specifies the cause of the fluctuation of the load of the motor 12 based on the comparison result for each of the forward path and the return path by the pattern comparison unit 26.

  By the way, in the wiper device 10 according to the present embodiment, each function shown in FIG. 3 is implemented by software by executing a drive control program.

  Next, with reference to FIG. 4, the operation of the wiper apparatus 10 when executing the drive control program according to the present embodiment will be described in detail. The drive control program is executed by the microcomputer 14 when an operation switch (not shown) that controls the operation of the wiper device 10 is turned on. Here, a case will be described in which reference pattern information is stored in the reference pattern storage unit 24 in order to avoid complications.

  In step 100 of the figure, a pulse signal input from the rotary encoder 16 is detected when the wiper blade 11 reciprocates, and at each wiping position in the operation range in the forward path and the return path when the wiper blade 11 reciprocates. A fluctuation pattern indicating a fluctuation state of the rotation speed of the motor 12 is detected.

  In the next step 102, the average value of the fluctuation state of the rotational speed indicated by the detected forward and backward fluctuation patterns and the average value of the fluctuation state of the rotational speed indicated by the reference pattern stored in the reference pattern storage unit 24 are obtained. The average value of the fluctuation state of the rotation speed indicated by the fluctuation pattern is compared with the average value of the fluctuation state of the rotation speed indicated by the reference pattern.

  In the next step 108, the factor causing the change in the load of the motor 12 is specified based on the comparison result.

  For example, in a wet state in which a predetermined amount of water droplets adhere to the contact surface of the windshield that comes into contact with the wiper blade 11 when reciprocating, and there is no wind on the contact surface, an example is shown in FIG. As shown, the fluctuation pattern and the reference pattern substantially coincide with each other on the forward path and the return path. In addition, the load on the motor 12 decreases when the amount of water droplets adhering to the contact surface of the windshield increases. However, when the amount of adhering water droplets exceeds a certain amount, the load on the motor 12 becomes substantially constant. The fluctuation pattern falls within a predetermined range of change from the reference pattern in both the forward path and the return path.

  On the other hand, when the windshield contact surface is in a dry state where no water droplets are attached and there is no wind on the contact surface, the load on the motor 12 for reciprocating the wiper blade 11 increases. As shown in FIG. 5B, the fluctuation pattern is generally smaller than the reference pattern in both the forward path and the backward path.

  On the other hand, when water droplets adhere to the windshield contact surface and the wind is hitting the windshield, as shown in FIG. 5C as an example, the fluctuation pattern is larger than the reference pattern in the forward path, On the return path, the variation pattern becomes smaller than the reference pattern.

  Therefore, by comparing the average value of the fluctuation state of the rotational speed indicated by the fluctuation pattern for each of the forward path and the return path with the average value of the fluctuation state of the rotational speed indicated by the reference pattern, the adhesion state of the water droplet on the contact surface from the comparison result And the state of the wind with respect to a contact surface can be specified.

  Therefore, in this step 108, when the average value of the fluctuation state of the rotational speed indicated by the fluctuation pattern in both the forward path and the return path is within a predetermined value from the average value of the fluctuation state of the rotational speed indicated by the reference pattern, Identify the glass as wet. This predetermined value is experimentally determined as defining a range in which the windshield is in a wet state that requires wiping with the wiper blade 11.

  On the other hand, the average value of the fluctuation state of the rotation speed indicated by the fluctuation pattern on one of the forward path and the return path is smaller than the average value of the fluctuation state of the rotation speed indicated by the reference pattern, and is indicated by the fluctuation pattern on the other of the forward path and the return path. When the average value of the fluctuation state of the rotational speed is larger than the average value of the fluctuation state of the rotation speed indicated by the reference pattern, it is specified that the wind is hitting the windshield.

  On the other hand, if the average value of the fluctuation state of the rotation speed indicated by the fluctuation pattern is smaller than the above predetermined value from the average value of the fluctuation condition of the rotation speed indicated by the reference pattern on both the forward path and the return path, it is determined that the rainfall has decreased. To do.

  In the next step 110, a drive control signal for controlling the rotation speed of the motor 12 according to the state of attachment of water droplets on the specified contact surface and the state of wind on the contact surface is output.

  In this step 110, when it is specified that the windshield is in a wet state, the wiper blade 11 is reciprocated while maintaining the rotational speed of the motor 12. When it is determined that the amount of rain has decreased, the rotational speed of the motor 12 is decreased to decrease the operating speed of the wiper blade 11, or the interval for reciprocating the wiper blade 11 is increased. When it is specified that the wind is hitting the windshield, for example, the wiper blade 11 is applied to the windshield with respect to an arm pressure adjusting device (not shown) that can adjust the pressure for pressing the wiper blade 11 against the windshield. Instruct to increase the pressure to be pressed.

  In the next step 112, it is determined whether or not an operation changeover switch (not shown) that controls the operation of the wiper apparatus 10 is turned off. If a negative determination is made, the process proceeds to step 100, whereas an affirmative determination is made. Terminates this drive control program.

  As described above, according to the present embodiment, the pattern comparison unit 26 compares the variation pattern detected by the variation pattern detection unit 22 with the reference pattern stored in the reference pattern storage unit 24, and the change factor identification unit 28 Since the variation state of the load on the motor 12 is changed from the variation state indicated by the reference pattern based on the comparison result by the pattern comparison unit 26, the cause of the change is specified, so that the wiper blade 11 is reciprocated. The factor of the change when the load of the motor 12 to be changed is changed can be easily specified.

[Second Embodiment]
By the way, when the vehicle equipped with the wiper device 10 is traveling, the wind hitting the windshield includes components due to the traveling wind corresponding to the vehicle speed of the vehicle and winds other than the traveling wind, for example, as shown in FIG. Thus, the fluctuation state of the load of the motor 12 changes due to the influence of the traveling wind and the head wind.

  Therefore, in the second embodiment, an example of determining a change in the load of the motor 12 due to the traveling wind corresponding to the vehicle speed of the vehicle with respect to the windshield and the wind other than the traveling wind when the wiper blade 11 is reciprocated. explain.

  FIG. 7 shows the configuration of the wiper device 10 according to the second embodiment. The same parts in FIG. 1 as those in FIG. 1 are denoted by the same reference numerals as those in FIG.

  As shown in the figure, the microcomputer 14 is connected to a vehicle speed sensor 18 that outputs a speed signal corresponding to the traveling speed of the vehicle, and a vehicle speed signal output from the vehicle speed sensor 18 is input. Thereby, the microcomputer 14 can detect the vehicle speed X of the vehicle based on the vehicle speed signal.

  FIG. 8 is a functional block diagram showing a functional configuration of the microcomputer 14 according to the present embodiment. Note that the same parts in FIG. 3 as those in FIG. 3 are denoted by the same reference numerals as those in FIG.

  In the load change amount deriving unit 40 according to the present embodiment, the change amount by which the average value of the fluctuation state of the rotational speed of the motor 12 changes in the forward path and the return path when the vehicle speed X of the vehicle and the wiper blade 11 are reciprocated. The relationship information indicating the relationship is stored in advance. In the load change amount deriving unit 40 according to the present embodiment, a function Rv (X) indicating a relationship between the vehicle speed X of the vehicle and the change amount is stored in advance as the relationship information. The load change amount deriving unit 40 detects the vehicle speed X of the vehicle based on the vehicle speed signal, and based on the detected vehicle speed X, the change amount of the average value of the rotational speed of the motor 12 in the forward path and the return path from the function Rv (X). Is derived.

  The pattern comparison unit 46 according to the present embodiment uses the average values of the rotational speed fluctuation states indicated by the detected forward and backward fluctuation patterns as changes in the forward and backward paths derived by the load change amount deriving unit 40. Correct each amount. If there is a difference in the average value of the fluctuation state of the rotational speed indicated by the fluctuation pattern of the forward path and the backward path after correction, the fluctuation pattern includes the influence of wind other than the traveling wind on the windshield. The pattern comparison unit 46 adds the same values with different signs to the average values of the forward and return paths so that there is no difference between the corrected average values of the forward and return paths when the influence of winds other than the traveling wind is included. Then, the average value of the fluctuation state of the rotation speed indicated by the fluctuation pattern after the addition is compared with the average value of the fluctuation state of the rotation speed indicated by the reference pattern stored in the reference pattern storage unit 24 for each of the forward path and the return path. To do.

  FIG. 9 shows a flow of processing of the drive control program according to the second embodiment. In the figure, the same processes as those in FIG. 4 are denoted by the same reference numerals as those in FIG.

  In step 101, the vehicle speed X of the vehicle is detected based on the vehicle speed signal, and the amount of change in the average value of the rotational speed of the motor 12 in the forward path and the return path is derived from the function Rv (X) based on the detected vehicle speed X.

  In the next step 103, the average value of the fluctuation state of the rotational speed indicated by the detected forward and backward fluctuation patterns is corrected by the forward and backward change amounts derived in step 101, respectively. If there is a difference in the average value of the fluctuation state of the rotational speed indicated by the fluctuation pattern of the forward path and the return path, the sign of the average value of the forward path and the return path is different so that there is no difference in the average value of the forward path and the return path after correction. The same value is added to each other, and the average value of the rotational speed fluctuation state indicated by the fluctuation pattern after the addition is obtained, and the rotational speed fluctuation state indicated by the reference pattern stored in the reference pattern storage unit 24 for each of the forward path and the backward path Compare with the average value of.

  Thereby, as shown in FIG. 10, the fluctuation pattern after removing the change by the winds other than driving wind and driving wind from the detected fluctuation pattern can be compared with the reference pattern.

  As described above, according to the present embodiment, it is possible to determine whether the windshield is in a wet state or a dry state by removing the influence of wind.

  In the second embodiment, a case has been described in which the fluctuation pattern after removing changes due to winds other than the traveling wind and the traveling wind is compared with the reference pattern, but the present invention is not limited to this. For example, the average value of the fluctuation state of the rotation speed indicated by the fluctuation pattern after each correction with the change amount is used, and the fluctuation of the rotation speed indicated by the reference pattern stored in the reference pattern storage unit 24 for each forward path and return path. You may compare with the average value of a state. Thereby, the fluctuation | variation of the load of the motor 12 by the influence of winds other than driving | running | working wind with respect to a windshield can also be pinpointed.

[Third Embodiment]
In the third embodiment, a description will be given of an example in which a sudden change in the load on the motor 12 due to a gust blowing on the windshield is specified.

  Since the configuration of the wiper device 10 according to the third embodiment is the same as that of the first embodiment (see FIG. 1), description thereof is omitted here.

  FIG. 11 is a functional block diagram showing a functional configuration of the microcomputer 14 according to the present embodiment. Note that the same parts in FIG. 3 as those in FIG. 3 are denoted by the same reference numerals as those in FIG.

  As shown in the figure, the microcomputer 14 includes a fluctuation pattern temporary storage unit 50 that temporarily stores a predetermined number of detected fluctuation patterns in order from the most recently detected one.

  The pattern comparison unit 56 calculates the average value of the fluctuation state of the rotation speed indicated by the detected fluctuation pattern, the average value of the fluctuation state of the rotation speed indicated by the reference pattern stored in the reference pattern storage unit 24, and the reference pattern. Each of the values is compared with the average value of the fluctuation state of the rotational speed indicated by the fluctuation pattern that is back a predetermined number of times from the fluctuation pattern stored in the storage unit 24.

  The change factor specifying unit 58 specifies the cause of the fluctuation of the load of the motor 12 based on the comparison result for each of the forward path and the return path by the pattern comparison unit 56.

  FIG. 12 shows the flow of processing of the drive control program according to the third embodiment. In the figure, the same processes as those in FIG. 4 are denoted by the same reference numerals as those in FIG.

  In step 105, it is determined whether or not a variation pattern that is traced back a predetermined number from the variation pattern detected in the variation pattern temporary storage unit 50 is stored. If the determination is affirmative, the process proceeds to step 106, while a negative determination is made. When it becomes, it transfers to step 109.

  In step 106, the average value of the fluctuation state of the rotational speed indicated by the detected fluctuation pattern is the average value of the fluctuation state of the rotational speed indicated by the fluctuation pattern retroactive by a predetermined number from the fluctuation pattern stored in the reference pattern storage unit 24. Compare with the average value.

  In step 109, if there is a difference of a predetermined value or more as a result of the comparison in step 106, it is detected that there is a sudden load fluctuation of the motor 12, and the rotational speed of the motor 12 is maintained as it is. Take control.

  As a result, as shown in FIG. 13, it is possible to suppress a change in the operating speed of the wiper blade 11 due to a sudden change in the load of the motor 12 due to a gust of wind blowing on the windshield.

  As described above, according to the present embodiment, it is possible to detect that the load of the motor 12 has suddenly changed.

  In each of the above embodiments, a case has been described in which a change in the load of the motor 12 is detected by detecting a change in the rotational speed of the motor 12 when the wiper blade 11 reciprocates. For example, the load variation of the motor 12 may be detected by detecting the current value of the current supplied to the motor 12 when the wiper blade 11 reciprocates.

  In each of the above embodiments, the case where the average value of the fluctuation state of the rotational speed indicated by the fluctuation pattern is compared with the average value of the fluctuation state of the rotation speed indicated by the reference pattern has been described. For example, the peak value of the rotation speed may be compared, and the difference pattern is obtained by comparing the fluctuation pattern with the reference pattern at each wiping position where the wiper blade 11 reciprocates. Also good.

  In addition, the configurations (see FIGS. 1, 3, 7, 8, and 11) of the wiper device 10 and the microcomputer 14 described in the above embodiments are merely examples, and do not depart from the gist of the present invention. Needless to say, it can be appropriately changed.

  The processing flow of the drive control program (see FIGS. 4, 9, and 12) described in the above embodiments is also an example, and can be appropriately changed without departing from the gist of the present invention. Needless to say.

  In addition, the wiper device 10 described in each of the above embodiments is mounted on a vehicle and wipes raindrops attached to the windshield by reciprocating the wiper blade 11, but the present invention is not limited thereto. Is not to be done. That is, it is not limited to what is mounted on the vehicle, and the object to be wiped is not limited to the windshield, and further, what is wiped is not limited to raindrops.

It is a functional block diagram which shows the structure of the wiper apparatus which concerns on 1st Embodiment. It is a graph which shows the load of the motor at the time of making a wiper blade reciprocate. It is a functional block diagram which shows the function structure of the microcomputer which concerns on 1st Embodiment. It is a flowchart which shows the flow of a process of the drive control program which concerns on 1st Embodiment. It is a graph which shows the difference of the variation pattern and reference pattern which were detected concerning a 1st embodiment. It is a graph which shows the change of the fluctuation pattern by the influence of wind other than driving wind by driving | running | working of a vehicle, and driving wind. It is a functional block diagram which shows the structure of the wiper apparatus which concerns on 2nd Embodiment. It is a functional block diagram which shows the function structure of the microcomputer which concerns on 2nd Embodiment. It is a flowchart which shows the flow of a process of the drive control program which concerns on 2nd Embodiment. It is a schematic diagram which shows the flow at the time of comparing the fluctuation pattern and reference | standard pattern which concern on 2nd Embodiment. It is a flowchart which shows the flow of a process of a drive control program. It is a functional block diagram which shows the function structure of the microcomputer which concerns on 3rd Embodiment. It is a flowchart which shows the flow of a process of the drive control program which concerns on 3rd Embodiment. It is a graph which shows the change of the fluctuation pattern by the influence of a gust of wind.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Wiper apparatus 11 Wiper blade 12 Motor 22 Change pattern detection part (detection means)
24 Reference pattern storage unit (storage means)
26 Pattern comparison unit (comparison means)
28 Change factor identification unit (identification means, detection means)
50 Fluctuation pattern temporary storage section (storage means)

Claims (7)

A motor for reciprocating the wiper blade;
Detecting means for detecting a fluctuation pattern indicating a fluctuation state of a load on the motor when the wiper blade is reciprocated;
Storage means for preliminarily storing, as a reference pattern, the variation pattern when the wiper blade is reciprocated with a predetermined external factor with respect to the contact surface with which the wiper blade contacts when reciprocating;
Comparison means for comparing the variation pattern detected by the detection means with a reference pattern stored in the storage means;
A specifying means for specifying a factor of the change when the change state of the load on the motor is changed from the change state indicated by the reference pattern based on the comparison result by the comparison means;
Wiper device with The wiper device according to claim 1, wherein the predetermined state is a state in which a predetermined amount of water droplets are attached to the contact surface and no wind is applied to the contact surface. The detection means detects a fluctuation pattern separately for each of the forward path and the return path when the wiper blade is reciprocated.
The storage means stores in advance a reference pattern separately for each of the forward path and the return path when the wiper blade is reciprocated.
The wiper device according to claim 1, wherein the comparison unit compares the variation pattern with the reference pattern for each of the forward path and the return path. The detecting means detects a fluctuation state of a load state of the motor by detecting a fluctuation state of a current value of the current supplied to the motor or a rotation speed of the motor when the wiper blade is reciprocated. The wiper device according to any one of claims 1 to 3, wherein a pattern is detected. The comparison means compares the fluctuation pattern with the reference value stored in the storage means by comparing the average value of the load fluctuation state indicated by the fluctuation pattern with the average value of the load fluctuation state indicated by the reference pattern stored in the storage means. The wiper device according to any one of claims 1 to 4, wherein the wiper device is compared with a pattern. The storage means temporarily stores at least a predetermined number of variation patterns detected by the detection means in order from the most recently detected variation pattern,
The comparison unit compares the variation pattern detected by the detection unit with the reference pattern stored in the storage unit and the variation pattern traced back from the variation pattern stored in the storage unit, respectively.
The wiper device according to any one of claims 1 to 5, further comprising detection means for detecting sudden fluctuations in a load on the motor based on a comparison result by the comparison means. A motor for reciprocating the wiper blade;
Detecting means for detecting a fluctuation pattern indicating a fluctuation state of a load on the motor when the wiper blade is reciprocated;
Storage means for temporarily storing at least a predetermined number of the fluctuation patterns detected by the detection means in order from the most recently detected pattern;
Comparison means for comparing the fluctuation pattern detected by the detection means with the fluctuation pattern retroactive to the predetermined number of times from the fluctuation pattern stored in the storage means;
Detecting means for detecting a sudden change in load on the motor based on a comparison result by the comparing means;
Wiper device with

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