In this article, you will learn about the PLC-based automatic car washing system project using ladder logic programming and explanation.

PLC Car Washing

Problem Solution

1. The car entry sensor triggers the process and turns the conveyor belt ON to move the car.
2. The soapy water sprinkler turns ON when the stage 1 sensor detects the car and does the process for a certain time.
3. Brusher turns ON when stage 2 sensors detect the car and do the process for a certain time.
4. The clean water sprinkler turns ON when stage 3 sensors detect the car and do the process for a certain time.
5.  The dryer turns ON when stage 4 sensors detect the car and do the process for a certain time.
6. The car exit sensor triggers the conveyor motor to turn off.

PLC Car Washing Logic

PLC Program Description

1. Latching rung to operate the system through Master Start and Stop PB.
2. The car entry sensor triggers the memory bit which will turn on the conveyor motor
3. ON/OFF operation of conveyer motor is happening in this rung using various conditions like Sensor input and timer done output.
4. When the car reached stage 1 sensor conveyor motor should stop and the water sprinkler should be ON for 10 sec. At the end of the water sprinkler timer, Conveyer will again be ON because of the parallel contact
5. When the car reached stage 2 sensor conveyor motor should stop and the brusher should ON for 10 sec. At the end of the brushing process, Conveyer will again be ON because of the parallel contact.
6. When the car reached stage 3 sensor conveyor motor should stop and the water sprinkler should be ON for 10 sec. At the end of the water sprinkler timer, Conveyer will again be ON because of the parallel contact.
7. When the car reached stage 4 sensor conveyor motor should stop and the water sprinkler should be ON for 10 sec. At the end of the water sprinkler timer, Conveyer will again be ON because of the parallel contact.
8. When the car reached the exit, the car exit sensor will trigger the car wash done indication lamp.

Note: This PLC example is from the Omron PLC course.

Author: Hema