Device for estimating the behavior of road-users

Claim 1

Device for determining the proportion of traffic of moving bodies exceeding a speed threshold, the device comprising a case, the case comprising sensing means for providing a signal representative of the speed of a moving body and having a converting means to convert the sensed signal into a train of pulses which converting means adjusts the frequency of the pulses according to the speed of the sensed body and further having counting means for counting the number of pulses in a time period; and the case further comprising, mounted externally thereof, a means to indicate the number of moving bodies exceeding the threshold and a means to indicate the total number of moving bodies sensed, wherein the case contains: a power source and a Doppler effect sensor, arranged to convey a sensed signal to an amplifier stage and thence to a counter control logic state, and then via an impedance adjustment circuit and derivative filter means, to a variable gain amplifier and a pass band filter; the signal then being conveyed to a trigger stage having a variable input arranged to supply a signal to a first monostable circuit which conveys a signal to a photocoupler controlling a counter to count the total number of bodies sensed, and a signal to a second monostable circuit to invert and to count the voltage peaks, the second circuit being connected to a logic circuit to convey the signal with inverted peaks to a program counter to count a value representing a predetermined speed threshold, and a signal to a third monostable circuit which controls a photocoupler arranged to activate a programmable counter to count those signals having a frequency equal to or greater than the programmed number in the counter therefor, thereby to count the number of moving bodies exceeding the speed threshold.