Rain Detection System for Power Windows in Automob…….ppt

Rain Detection System for Power Windows in Automobiles Group Four Brian Mitterer, Rob Herzog, Chintan Patel ECE 445 Senior Design Introduction We designed a sensor system that detects rain and rolls up the windows in an automobile The object is to grant the driver the convenience of having his or her car windows automatically close in the event of rain Benefits Protects the inside of a vehicle from water damage caused by rain Provides safety to the driver and passengers by eliminating distraction Provides convenience to drivers by allowing them to keep windows open while they are away and not having to rush out to close them if it begins to rain Product Features Reliable and low cost Compatible with any car with power windows Automatic drying with complete rooftop coverage Compact and easy to install User-override switch Rain Detection System System Overview Hardware components: Rain sensors, override switch, microcontroller, motor relays, voltage regulator and car battery Software components: Microcontroller (PIC) logic to implement the various functionalities. Overall Block Diagram Sensors Three proposals for the sensor to be used in the system Plan was to test all three designs and make an engineering decision based on resistance, sensitivity, reliability and dry time Sensor # 1 Overview First rain sensor design had three copper conducting plates with sponge material between them With this sensor placed on-end on top of the vehicle, rain water would saturate the sponges This would complete the circuit and allow current to flow from one conducting plate to another through the water in the sponge Senor # 1 Diagram Sensor # 1 Performance Resistance Sponge Thickness (in.) Avg. Resistance (Ohms) 1/4 2.4 MΩ 1/2 3.0 MΩ 1/8 1.6 MΩ Sensitivity needed to be soaked to detect Dry Time ~ 4 - 6 hours Reliability sponge will decay over time Sensor # 2 Overview Second rain sensor design consisted of two copper conducting plates covered with insulation o