Windscreen wiper control system and control method

Abstract

The invention discloses a windscreen wiper control system and method, the system comprises a single-chip microcomputer, the single-chip microcomputer is electrically connected with an LCD display, a key module, a rainfall sensing module and a motor driving chip, the key module comprises a first key, a second key, a third key and a fourth key, and the motor driving chip is electrically connected with the first key. The rainfall sensing module comprises a humidity sensor and an analog-to-digital converter, the motor driving chip is electrically connected with a stepping motor, and the output end of the stepping motor is connected with a windscreen wiper; the control method comprises a manual control method and an automatic control method. The speed of the windscreen wiper can be automatically adjusted according to the rainfall, and the driving safety is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent wipers, and in particular to a wiper control system and a control method. Background Art

[0002] Electric windshield wipers are driven by motors and are generally composed of wiper arms, wiper blade assemblies, rubber brush blades, brush blade supports, brush blade holders, wiper arm spindles, wiper base plates, motors, speed reduction mechanisms, drive rod systems, drive rod hinges, wiper switches, and wiper switch knobs. Of course, wipers with wiper ECUs are also equipped with electronic control units (ECUs). Electric windshield wipers are driven by motors. The left and right wiper blades of the wiper are pressed against the outer surface of the windshield by the wiper arms. The motor drives the speed reduction mechanism to rotate, and through the drive rod system, it makes reciprocating motions, driving the wiper arms and wiper blades to swing left and right to wipe the windshield.

[0003] Traditional wipers rely on manual control by the driver. When the rain changes suddenly, the driver needs to divert attention to adjust the wiper speed, which poses a great safety hazard when driving at high speeds or in bad weather conditions. The driver needs to stay highly focused during long driving, and manually adjusting the wipers all the time will increase the operational burden and psychological pressure, which may lead to accidents. Summary of the invention

[0004] The purpose of the present invention is to overcome the existing defects and provide a wiper control system and a control method which can automatically adjust the speed of the wiper according to the amount of rainfall, thereby improving driving safety.

[0005] The technical solution to achieve the above object is: a wiper control system, comprising a single chip microcomputer, wherein the single chip microcomputer is electrically connected to an LCD display, a key module, a rain sensor module and a motor drive chip;

[0006] The button module includes a first button, a second button, a third button and a fourth button, and the single chip microcomputer is electrically connected to the first button, the second button, the third button and the fourth button respectively;

[0007] The rain sensing module includes a humidity sensor and an analog-to-digital converter. The single-chip microcomputer is electrically connected to the humidity sensor via the analog-to-digital converter. The motor driving chip is electrically connected to a stepper motor. The output end of the stepper motor is connected to a wiper.

[0008] Preferably, the single chip microcomputer is also electrically connected to a first indicator light and a second indicator light.

[0009] Preferably, the single chip microcomputer, LCD display, key module, rain sensor module, motor drive chip, first indicator light and second indicator light are all connected to a PCB board.

[0010] Preferably, a power supply is provided on the PCB board, and the power supply is electrically connected to each electrical component.

[0011] Preferably, the control method of the wiper control system includes a manual control method and an automatic control method.

[0012] The manual control method includes the following steps:

[0013] S1 first turns on the power switch, each module enters the initialization mode, and the LCD display shows the current status of the system;

[0014] S2 Press the first button to enter the manual mode static state. At this time, the stepper motor stops rotating and the wiper gear is in gear "0". At the same time, the LCD display shows the current state of the system;

[0015] S3 judges the amount of rain by naked eyes. When it is light rain, the third button is pressed, and the wiper gear is at gear "1". The speed of the stepper motor is controlled by the single-chip microcomputer and the motor driver chip. When it is heavy rain, the fourth button is pressed, and the wiper gear is at gear "2". The speed of the stepper motor is controlled by the single-chip microcomputer and the motor driver chip. At the same time, the LCD display shows the current status of the system.

[0016] The automatic control method comprises the following steps:

[0017] S11 first turns on the power switch, each module enters the initialization mode, and the LCD display shows the current status of the system;

[0018] S12 presses the second button to enter the automatic mode. The rain sensing module automatically detects the amount of rainfall, and after automatic judgment and analysis, switches the wiper gear between "0", "1" and "2". The microcontroller and motor driver chip control the speed of the stepper motor. At the same time, the LCD display shows the current status of the system.

[0019] The beneficial effects of the present invention are as follows: the single-chip microcomputer is electrically connected to an LCD display, a key module, a rain sensing module and a motor driving chip respectively, the amount of rain is detected by a humidity sensor, and the signal is transmitted to the single-chip microcomputer via an analog-to-digital converter. The stepper motor is controlled by the joint action of the single-chip microcomputer and the motor driving chip, and the stepper motor can control and adjust the speed of the wiper, thereby improving driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the present invention;

[0021] Figure 2 It is a working principle diagram of the present invention;

[0022] Figure 3 It is the overall flow chart of the manual mode of the present invention;

[0023] Figure 4 It is the overall flow chart of the automatic mode of the present invention.

[0024] In the figure: 1. single chip microcomputer; 2. first button; 3. second button; 4. third button; 5. fourth button; 6. LCD display; 7. analog-to-digital converter; 8. humidity sensor; 9. motor driver chip; 10. stepper motor; 11. first indicator light; 12. second indicator light; 13. PCB board. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0026] The present invention will be further described below in conjunction with the accompanying drawings.

[0027] Example 1

[0028] like Figure 1 and Figure 2 As shown, a wiper control system includes a single chip microcomputer 1 (the single chip microcomputer 1 is the existing STC89C52 single chip microcomputer), an LCD display 6, a key module, a rain sensor module and a motor drive chip 9 (the motor drive chip 9 is the existing ULN2003A motor drive chip).

[0029] The single-chip computer 1 is electrically connected to an LCD display 6 (the LCD display 6 is an existing dot-matrix liquid crystal display LCD1602), a key module, a rain sensor module and a motor drive chip 9. The single-chip computer 1 is responsible for data acquisition, status display and command reception and execution, and is connected to a data acquisition interface, a status display interface and a command control interface. The LCD display 6 is used to display the amount of rain, the working state of the wiper, the gear size and the upper and lower limits of the starting rainfall, and provide real-time system information. The key control module is used to switch the working mode of the wiper, adjust the gear, set the upper and lower limits of the rainfall, etc., and these parameters can be adjusted manually;

[0030] Software settings for LCD display 6: The initialization function LCD1602_Init is used to initialize the LCD display 6. The initialization steps include setting the display mode, display control, cursor setting and screen clearing operations. First, the display mode is set to 8-bit data interface, two-line display and 5x7 dot matrix characters. Next, the display control is set to display on and cursor off. The text movement mode is set to text not moving and address automatically +1. Finally, the screen is cleared and a delay is performed to ensure the stability of command execution.

[0031] The display update function display is used to periodically update the content on the LCD display 6. The function first sets the display address to the first position of the first line, and then displays the character and numerical information in sequence. By judging the numerical range, the display format is adjusted to align the display content. The display includes water level information, and the characters of hundreds, tens and ones are displayed according to the size of the numerical value. The system's working mode and the status of the stepper motor 10 can also be displayed: if the system is in automatic mode, the character A is displayed; if it is in manual mode, the character M is displayed; if the stepper motor 10 is started, the character K is displayed; if the motor stops, the character G is displayed.

[0032] Next, the function sets the display address to the first position of the second line, displays the upper and lower water level information, and if the current state is 1 and the S0 flag is true, clears the upper water level display area; if not, displays the hundreds, tens, and ones characters according to the water level; displays the lower water level information in the same way as the upper limit; if the current state is 2 and the S0 flag is true, clears the lower water level display area; otherwise, displays the lower water level characters.

[0033] Software settings of the button module: The button module includes a first button 2, a second button 3, a third button 4 and a fourth button 5. The P3 port of the single-chip computer 1 is electrically connected to the first button 2, the second button 3, the third button 4 and the fourth button 5 respectively. The button processing function key_dispose is used to detect and process button input. The function scans the status of each button in a loop and de-bounces the status of each button. When it is detected that the button module is pressed and de-bounced, the system will switch the current state. The state variable state cycles between 0, 1, and 2. State 0 indicates that the system is in the automatic / manual mode switching state, state 1 indicates that the system is in the upper limit water level setting state, and state 2 indicates that the system is in the lower limit water level setting state.

[0034] When it is detected that the second button 3 is pressed, if the current system state is 1 (upper water level setting), the upper water level water_h is increased, and the new water level value is written to the EEPROM storage; if the current system state is 2 (lower water level setting), the lower water level water_l is increased, and the new water level value is written to the EEPROM storage; if the current system state is 0 (automatic / manual mode switching), the automatic / manual mode A_M is switched, and the stepper motor 10 start flag star_off is reset.

[0035] When it is detected that the third button 4 is pressed, if the current system state is 1 (upper water level setting), the upper water level water_h is reduced, and the new water level value is written to the EEPROM storage; if the current system state is 2 (lower water level setting), the lower water level water_l is reduced, and the new water level value is written to the EEPROM storage; if the current system state is 0 (automatic / manual mode switching) and the system is in manual mode, the stepper motor 10 start flag star_off is switched, and the stepper motor 10 speed flag speed_flag is adjusted.

[0036] When it is detected that the fourth button 5 is pressed, if the system is in automatic mode, the speed flag speed_flag of the stepper motor 10 is increased and cycles between 0, 1, and 2 to control the speed of the stepper motor 10 .

[0037] The single chip computer 1 is also electrically connected to a first indicator light 11 and a second indicator light 12. In addition, the key processing function also includes control logic for the states of the first indicator light 11 and the second indicator light 12. When the system is in automatic mode, the first indicator light 11 is turned on; when the system is in manual mode, the second indicator light 12 is turned on; according to the value of the motor speed flag speed_flag, the delay value Value of the motor is adjusted to control the speed of the motor;

[0038] Software settings of the motor driver chip 9: The motor driver chip 9 is electrically connected to a stepper motor 10 (the stepper motor 10 is an existing 28BYJ-48 stepper motor), and the output end of the stepper motor 10 is connected to a wiper; precise control of the stepper motor 10 is achieved through hardware connection and software control.

[0039] The forward and reverse steps are defined by two arrays zz and fz respectively. Each array contains the stepping sequence of the stepper motor 10 when it rotates forward and reverse. Each element represents the power-on state of a coil. By outputting these steps in sequence, the stepper motor 10 rotates. DJ_dat is defined to record the number of steps of the stepper motor 10, loop is used to record the current step position, speed_flag controls the speed of the stepper motor 10, Value is the delay value, which is used to adjust the rotation speed of the stepper motor 10, A_M represents the automatic / manual mode of the stepper motor 10, and star_off is used to control the start and stop of the stepper motor 10.

[0040] The motor control function control_motor realizes the forward and reverse control of the stepper motor 10. The function first determines whether the A_M variable is 0, that is, whether the system is in automatic mode. If so, the police_dispose function is called to process the sensor data to determine the running status and speed of the motor. If the star_off flag is 0, it means that the motor is in the starting state and the rotation of the motor is controlled. When rotating forward, the step data of the zz array is output to the P1 port through the whi le loop to realize the rotation of the motor. After each step is completed, the delay function LCD1602_delay is used to delay control of the speed, and the step index and number of steps are updated. When reversing, the step data of the fz array is output to the P1 port to realize the reversal of the motor back to the initial position.

[0041] Software setting of the rain sensing module: The rain sensing module includes a humidity sensor 8 (the humidity sensor 8 is the existing YL-69 humidity sensor) and an analog-to-digital converter 7 (the analog-to-digital converter 7 is the existing ADC0832 analog-to-digital converter). The single-chip computer 1 is electrically connected to the humidity sensor 8 through the analog-to-digital converter 7. The sensor data processing function poll_dispose is used to process the state of the stepper motor 10 according to the data of the humidity sensor 8. First, the infrared detection is turned off, and then the start and speed mode of the stepper motor 10 are determined according to the current water level value dat_value and the preset upper and lower limit thresholds water_h and water_l. If the current water level value is greater than the upper limit threshold, the motor is started and set to high-speed mode; if the current water level value is between the upper and lower limits, the motor is started and set to low-speed mode; if the current water level value is less than the lower limit threshold, the motor will stop working.

[0042] The timer interrupt functions time_0 and time_1 are used to regularly update the motor status and realize automatic control. The time_0 interrupt is used to regularly read the sensor data and calculate the current water level value. Each time the interrupt is triggered, the current counter values ​​TH0 and TL0 are reset, and the current water level value is obtained by accumulating the sensor data read multiple times and calculating the average value. The time_1 interrupt is used to update the LCD display and process key input. Each time the interrupt is triggered, the display function is called to update the display content, and the key_dispose function is called to process the key status.

[0043] The analog signal of the humidity sensor 8 is converted into a digital signal by the analog-to-digital converter 7 and transmitted to the single-chip microcomputer 1 for processing.

[0044] The timer interrupt function time_0 is used to periodically collect data from the humidity sensor 8 and calculate the current water level value. The function first resets the timer counter values ​​TH0 and TL0 to ensure timing accuracy. The frequency of data collection is controlled by counting the variable ms_1. When ms_1 is less than 10, the sampled value dat1 of the humidity sensor 8 is accumulated in a loop. Each sampling reads the output value of the analog-to-digital converter 7 through the A_D function, which represents the digital value after the analog signal of the humidity sensor 8 is converted. After collecting 10 times, the average value is calculated, and the actual water level value is calculated based on the characteristics and calibration parameters of the humidity sensor 8. If the average value dat1 is less than or equal to 36, it is set to 36 to prevent negative values ​​from occurring. Subtract 36 from dat1 and divide it by 2.19 to get the actual water level percentage dat. Finally, reset the variables i and dat1 to prepare for the next round of sampling. When the ms_1 count reaches 10, the S0 flag is inverted and ms_1 is reset.

[0045] The system state control function poll_dispose determines the system's operating state and control parameters according to the current water level value dat_value and the preset upper water level water_h and lower water level water_l thresholds. Turn off the infrared flag ir_on to ensure that the data of the humidity sensor 8 is not disturbed. When dat_value is greater than the upper water level water_h, start the stepper motor 10, set star_off to 0, and set speed_flag to 2, indicating high-speed mode. When dat_value is between the lower water level water_l and the upper water level water_h, start the stepper motor 10, set star_off to 0, and set speed_flag to 1, indicating low-speed mode. When dat_value is less than the lower water level water_l, stop the stepper motor 10, set star_off to 1, and set speed_flag to 0, indicating a stationary state.

[0046] The single chip microcomputer 1, LCD display 6, key module, rain sensor module, motor drive chip 9, first indicator light 11 and second indicator light 12 are all connected to a PCB board 13; a power supply is provided on the PCB board 13, and the power supply is electrically connected to each electrical component, and the power supply can supply power to each electrical component.

[0047] The control method of the wiper control system includes a manual control method and an automatic control method.

[0048] Combination Figure 3 Specifically, the manual control method includes the following steps:

[0049] S1 first turns on the power switch, and each module enters the initialization mode. In the manual mode, the letter M will be displayed on the LCD display 6, indicating that the wiper is currently controlled manually;

[0050] S2 Press the first button 2 to enter the manual mode static state. At this time, the stepper motor 10 stops rotating and the wiper gear is in gear "0". In the initial state, the letter G will be displayed on the LCD display 6, which means that the wiper is currently in a static state. At the same time, the first indicator light 11 will light up to indicate that the wiper is not turned on. In this state, the different functions of the wiper can be switched and tested by operating other buttons on the PCB board 13;

[0051] S3 judges the amount of rain with naked eyes. When it is drizzling, the third button 4 is pressed. At this time, the LCD display 6 shows that the wiper gear is "1" and the letter will change from G to K. This change indicates that the wiper starts to work and will swing back and forth at a slow speed.

[0052] When the rainfall is heavy, press the fourth button 5, the gear position of the wiper will change from "1" to "2", which means that the wiper starts to swing at a higher speed to cope with heavier rainfall. Press the fourth button 5 again, the gear position will change from "2" to "0", and the wiper will stop working;

[0053] Combination Figure 4 Specifically, the automatic control method includes the following steps:

[0054] S11 first turns on the power switch, and each module enters the initialization mode. In the manual mode, when the second button 3 on the control panel is pressed, the letter M on the LCD display 6 will change to A, and at the same time, the second indicator light 12 lights up, indicating that the wiper has switched to the automatic mode;

[0055] S12 Press the second button 3 to enter the automatic mode. The rain sensor module automatically detects the amount of rain. After automatic judgment and analysis, the wiper gear is switched between "0", "1" and "2". In the automatic mode, the rain sensor automatically detects the amount of rain. When the rain is lower than the preset lower limit, the wiper will remain stationary and the gear will be displayed as "0". When the rain exceeds the lower limit but is not higher than the upper limit, the wiper will automatically start and start working in low speed mode. At this time, the gear will change from "0" to "1". Increase the amount of rain. When the detected rain exceeds the preset upper limit, the wiper will automatically switch to high speed working mode. At this time, the wiper gear will change from "1" to "2" to cope with stronger rainfall.

[0056] Example 2

[0057] The upper and lower limits of wiper rainfall can also be adjusted according to needs, so as to cope with rainfall in different situations. In automatic mode, when the first button 2 is pressed, the upper limit value will start to flash, indicating that the upper limit value can be adjusted at this time. Pressing the second button 3 can increase the value of the upper limit value, and pressing the third button 4 can decrease the value of the upper limit value. When the upper limit value is adjusted, press the first button 2 again, the lower limit value will start to flash. At this time, the lower limit value can be adjusted in the same way. Press the second button 3 to increase the value of the lower limit value, or press the third button 4 to decrease the value of the lower limit value. After all adjustments are completed, press the first button 2 again to save all settings. Even after power failure, the system will still retain the adjusted upper and lower limits when power is restored, ensuring that the wiper automatically adjusts to the most suitable working state under different rainfall conditions.

[0058] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified, or some or all of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wiper control system, characterized in that: It comprises a single chip microcomputer (1), wherein the single chip microcomputer (1) is electrically connected to an LCD display (6), a key module, a rain sensor module and a motor drive chip (9); The key module comprises a first key (2), a second key (3), a third key (4) and a fourth key (5), and the single chip computer (1) is electrically connected to the first key (2), the second key (3), the third key (4) and the fourth key (5) respectively; The rain sensing module comprises a humidity sensor (8) and an analog-to-digital converter (7); the single-chip computer (1) is electrically connected to the humidity sensor (8) via the analog-to-digital converter (7); the motor driving chip (9) is electrically connected to a stepping motor (10); and the output end of the stepping motor (10) is connected to a wiper.

2. The wiper control system according to claim 1, characterized in that: The single chip computer (1) is also electrically connected to a first indicator light (11) and a second indicator light (12).

3. The wiper control system according to claim 1, characterized in that: The single chip computer (1), LCD display (6), key module, rain sensor module, motor drive chip (9), first indicator light (11) and second indicator light (12) are all connected to a PCB board (13).

4. The wiper control system according to claim 3, characterized in that: The PCB (13) is provided with a power supply, and the power supply is electrically connected to each electrical component.

5. A control method for a wiper control system according to any one of claims 1 to 4, comprising a manual control method and an automatic control method, The manual control method includes the following steps: S1 first turns on the power switch, and each module enters the initialization mode, and the LCD display (6) displays the current status of the system; S2 presses the first button (2) to enter the manual mode static state, at which time the stepper motor (10) stops rotating, the wiper gear is in gear "0", and at the same time, the LCD display (6) displays the current state of the system; S3 judges the amount of rainfall by naked eyes. When it is light rain, the third button (4) is pressed. At this time, the gear of the wiper is at gear "1", and the speed of the stepper motor (10) is controlled by the single-chip computer (1) and the motor driver chip (9); when it is heavy rain, the fourth button (5) is pressed. At this time, the gear of the wiper is at gear "2", and the speed of the stepper motor (10) is controlled by the single-chip computer (1) and the motor driver chip (9). At the same time, the LCD display (6) displays the current state of the system; The automatic control method comprises the following steps: S11 first turns on the power switch, each module enters the initialization mode, and the LCD display (6) displays the current status of the system; S12 presses the second button (3) to enter the automatic mode, the rain sensing module automatically detects the amount of rain, and after automatic judgment and analysis, switches the gear of the wiper between gear "0", gear "1" and gear "2", the single chip computer (1) and the motor driving chip (9) control the speed of the stepping motor (10), and at the same time, the LCD display (6) displays the current state of the system.

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