| 摘要 |
In the method for measuring the speed of vehicles on a measurement section of known length, the voltage pulses produced by the loads in the detector cables when they are driven over are firstly differentiated by an electronic circuit, amplified and subsequently fed to a fast analog/digital converter which enables the signals obtained to be evaluated by computer. Digital pulse recognition by means of numerical integration of the rise in the signal of the received voltage pulse is performed in the computer. The precise drive-over instant is determined for each detector cable by providing that after the maximum value of the received voltage pulse is exceeded the zero crossing is detected by the computer and fixed as measuring point for time measurement in order to determine the driving (road) speed. In order to ensure a unique vehicle identification when measuring speed, the signals coming from an induction loop arranged upstream of or between the detector cables are linked to the voltage pulses coming from the detector cables in such a way that there is produced from the received signals and voltage pulses a pulse combination which can be evaluated in the computer in order to prevent erroneous measurement due to a plurality of vehicle axles.
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