I am looking for a device for which can be installed behind the wheels of a motor vehicle which will detect and alert driver based upon its proximity to the roadside kerb. This will early warning system which can help avoid damage to the tyre/rim which costs a fortune to repair. Please have a look at the attached drawing first and then continue reading.
You will notice here that a upside down Y shaped arm (lets call it YA) is attached behind the wheel to the point where brakes are attached to the hub / axle. Further down the arm two sections will split here one will detect kerb nearness if reversing (rear one) or proceeding (front one). Keep in mind that steering wheel will move whole wheel, since our YA is attached to brakes mounting it will move with the wheel and will always remains to the same position from the viewpoint of wheel. We have to keep sensors away from the wheel exactly as much as needed to avoid any interferences from tyres. Spring attached to both the arms will ensure that it is fully flexible incase any minor impact occurs to the YA. Spring will be necessary due to proximity from the ground too.
Mode of operation:
During installation ultrasound distance sensor will have to be calibrated due to variance of width among various types of tyres. Once calibrated sensor will keep sensing while car is started. We have to use a vibration sensor to detect when car has been started and when turned off. Based upon car's start/stop whole unit should wakeup or go to sleep. Distance sensor will keep looking ahead (laser straight) for any obstacles beyond tyre width, for example if tyre width is [url removed, login to view] (245mm) then it should look from [url removed, login to view] to 24.5+30cm=[url removed, login to view] maximum. Based upon the distance of obstacle sensed a continuous frequency beep should be made by attached buzzer. Frequency and buzzer intensity should be highest if obstacle is less then [url removed, login to view] and frequency should reduce as distance increases upto no sound beyond 50 cm. Keep in mind that sensor has to be detecting kerb and other obstacles, kerb is the main requirement which is like concrete cement (gray or dark gray colour) and often having an angle likely to be around 10 degree to 30 degrees negative or positive. Buzzer will be mounted on the arm itself and we can set it to play different sound for different wheels in the same car. Main struggle is power here which I don't want to draw from car battery because of stretching cables across the car issue. I would like to use portable power solution here, e.g. a rechargeable battery with charger connected to a low power dynamo having a small fan blade to use wind power blowing under the car (which will always happen when car is moving) however moving part could be prone to failure and will collect dirt and grease over period of time. We can use other options like shake charger or simple rechargeable battery. Before we decide on power we have to calculate how much current will be drawn on this device, only then we can conclude what to use.
Keep in mind we have to use the cheapest possible solution in smallest possible package to be able make it viable solution.
I want a micro-controller based circuit for this project and I will detail some minute details and sensor's behaviour with the distance once we start making it.