WINDSCREEN WIPER WING STEPPER MOTOR CONTROL

 Windscreen wiper wing stepper motor control:

·        Windscreen wiper is a device which is used to clear the front glass of the cars,buses, train etc., during raining days. It will oscillate an arm back and forth in an arc like a windscreen wiper. A traditional mechanical solution for this problem is shown in fig.

·    It uses a brush-less stepper motor.It uses a principle of four-bar mechanisms.It is using a worm and gear to reduce the speed and to increase the torque up to 50:1. It consists of a crank which rotates about its center and a connecting rod which converts rotary movement to linear movement of the linkage .  An end of a connecting rod is connected to the crank and other with wiper arm. Rotation of crank causes connecting rod to impart an oscillatory motion to wiper arm. We can also have wiper arm in the passenger side, a linkage will connect both the sides.

·     An alternative mechatronics approach for this problem is to use a stepper motor. For operating a stepper motor a microprocessor or a micro controller can be used.The input to the stepper motor is required to cause it to rotate a number of steps in one direction and reversing the same number of steps in other direction while the data is reversed.

  

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Rain Sensor:

·         When the vehicle is started the rain sensor gets the supply power and it will scan for the moisture content in the windshield.The sensor is interfaced with the micro controller. An infrared beam is reflected off the outside surface of the windshield to the infrared sensor array. When moisture strikes the windshield, the system experiences an interruption to its infrared beam. Advanced analog and  digital signal processing determines the intensity of rain or snow. The sensor communicates to the wiper control module to switch on the wiper motor and controls the wipers automatically according to the moisture intensity detected.

• The sensor will send output voltage according to the rain amount. If there is no rain then the voltage will be more than 4V and if it is raining the output will be less than 4V. When rain is detected then the motor will be turned on at lower speed. If the voltage drops less than 2.5V then the motor will be turned ON at higher speed.

TYPES:

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