Build your own Black Ice Detection system for your car using AutoPi
The term “Black ice” refer to a winter phenomenon, where a layer of ice on the road is so thin it becomes transparent and thus appears “black” from the road below. This is a very common situation during winter times and can create hazardous situations for vehicles and pedestrians. The phenomenon often occurs when the temperature is right around freezing point and when a light rain hits a road surface which is below freezing point.
Did you know?
Over 1,300 people are killed and more than 116,800 people are injured in vehicle crashes on snowy, slushy or icy pavement annually.
The Bureau of General Safety in Maine (United States) has issued a list of things to watch out for when driving, this includes:
- Pavement looks new or dark
- Low-lying areas which can collect melted water that can refreeze
- Use seat covers
- Shaded road areas, where the sun can not heat it up
- Slow down
- Wear seatbelts
- Drive with headlights on
- Increase safety margins to vehicles ahead
- Avoid quick steering movements
What is AutoPi?
AutoPi is a small device that plugs into the OBD-II port of your car.
Once connected, the AutoPi device will automatically start working. It has 4G/3G connectivity, so it is always connected to the Internet. It also comes with a lot of other features, for example continuous GPS tracking. One of the main advantages of the AutoPi is its many extension options.
It comes with an online cloud dashboard, that you can login to from any device. From here you can setup your system and do real-time tracking of your vehicle telematics.
Black Ice detection using AutoPi
Some car models have outside temperature sensors built in. These temperature sensors is meant to measure the outside air temperature, but often does not give a precise reading of the air temperature because of engine heating. And when dealing with “black ice” it is more precise to know the surface temperature.
AutoPi has a lot of extension possibilities through one of its ports. This makes it possible to build and extend a lot of different things with your AutoPi. An example is this infrared temperature sensor from Phidgets Inc:
This specific sensor can be connected directly to one of the USB ports of the AutoPi dongle. An infrared thermometer measures the infrared energy from an object and uses this to determine the temperature of that object (or surface). Using this technique it is possible to measure temperature without touching the object.
The infrared temperature sensor is mounted on the vehicle (a specific casing can be acquired for the Phidgets sensor) and set to point towards the road surface in a forward pointing angle, this must be calibrated to give the best result.
When the sensor has been installed in the vehicle, it is simply connected to the USB port of the AutoPi.
The AutoPi dongle and IoT platform contains a lot of possibilities to extend the temperature input from the Phidget sensor. Because all of the input and outputs in the AutoPi dongle, it can be combined in a rule based system (also known as an if-this-then-that system). Using this it is possible to build an in-car warning system using the built-in speaker in the AutoPi dongle.
The AutoPi dongle will record the temperature measured by the infrared temperature sensor, and based on the rules defined in the AutoPi cloud dashboard it is able to react on these measurements. An example could be to warn the driver by, using the speaker in the dongle. This can be accomplished using a cloud based service, like Google Assistant.
This is an example of how the AutoPi can be used to extend the usage and safety of your vehicle. We hope you got a better understanding of what you can do with the AutoPi.
Other blog posts for further reading
Saving your car interior on a hot day - Making a cabin overheating protection system using AutoPi
Studies show that on a hot summer day the temperature inside your vehicle will rise dramatically within just 10 minutes after you parked. HeatKill.org reports that with an outside temperature of 27 C (80 F), the inside temperature could rise to as high as 37 C (99 F) after just 10 minutes. The inside of your car becomes an oven roasting your interior. The sun will permanently damage the color and look of everything it touches, thereby degrading the value of your car.
Switching from Raspberry Compute to Raspberry Zero
During the design phase of the AutoPi, it was decided to use the Raspberry Compute Module. The Raspberry Compute Module is small, versatile and expandable in a lot of ways, which suited the AutoPi project perfect. All the pinouts from the Broadcom BCM2835 processor is available through the SODIMM DDR2 interface on the Compute Module. This gave us a lot of possibilities during the design phase of the AutoPi and therefore the Compute module was an obvious choice for us as a main processor.
Discover hidden functions in your car (using CAN bus sniffing)
All modern vehicles today is controlled by multiple Electronic Control Units (ECU), which you can think of as small computers controlling all electrical components in your car. Using the OBD-II port and an AutoPi it is possible to communicate with the ECUs. One of the ECU’s is called the Engine Control Module (ECM). This is responsible for communication with a lot of subsystems, like transmission, power steering, windows and doors. These subsystems communicates on a network bus called Controller Area Network (CAN), by broadcasting messages on the bus.