India is a country where the maximum number of deaths occurs due to road accidents and most of these occur due to over speeding. Manifold attempts have been made to produce reliable and efficient means of detecting over speeding vehicles. The hand held over speeding detector is one such device. The disadvantage of such a device was that it was cumbersome and required expert hands for it's operation; also by the time a speed reading is obtained, the vehicle would long have gone.
Thus the necessities for a more reliable and easily operable device made us think of doing the same as a project. The special features of this device are that it can be operated from as far as 100m and thus the over speeding vehicle can easily be identified.Also, distinct from the conventional speed detector, this device operates not on the echo principle or the Doppler effect, but on highly coherent laser beams. There is also the added advantage that it can be setup on any road and is also easily transferable.
Overview Of The Product
The product is a sleek hand held device that can be operated by the traffic official whenever he observes an over speeding vehicle, to obtain the correct speed of the vehicle. It has a 2 digit 7-segment display, which can display speeds up to 97km/h. It also has two switches, which are used for starting the device and for enabling it only when required. The state of the device is indicted by three status indicating LEDs which display the following conditions: a green LED indicating power on, an orange LED indicating the set or enabled condition, and a red LED indicating speeds in excess of 100 km/h.
This sleek and handy version enables the traffic official to operate the device without any problem and with utmost ease. Moreover, the product uses only the most commonly available CMOS ics, which facilitate easy maintenance. The circuit in itself is very simple and easy to implement so that troubleshooting is made very simple. The other features of the device are that it can be easily set upon any road and can be easily transferred. Also, since this can operate on any source of light, it is easily implementable and guarantees satisfactory performance.
Principle Of Operation
The operation of "Over speed Detector" depends on the simple one-dimensional equation of motion, i.e. speed= distance /time. It consists basically of a source - sensor couple and a hand held device. The source- sensor couple is placed on the road at a distance of 1m from each other.When the operator gets a visual indication that a vehicle is over speeding, he can initiate the device from as far as 100m.When the vehicle cuts the first laser beam, the sensor is set and the transition pulse is transferred to the hand held device.
The device now starts counting from a fixed clock. When the vehicle cuts the second laser beam, the transition pulse is again transferred to the device, which stops the counting. What we have now obtained is the time taken for the vehicle to cover a distance of 1m. This count is then decoded to obtain the speed-reading. Once the speed-reading is obtained, the official can decided whether the vehicle is over speeding or not as per the rules and regulations pertaining to different road conditions.