A Highly Selective Vehicle Classification Utilizing Dual-Loop Inductive Detector

Abstract

In general, currently employed vehicle classification algorithms based on the magnetic signature can distinguish among only a few vehicle classes. The work presents a new approach to this problem. A set of characteristic parameters measurable from the magnetic signature and limits of their uncertainty intervals are determined independently for each predefined class. The source of information on the vehicle parameters is its magnetic signature measured in a system that enables independent measurement of two signals, i.e. changes in the active and reactive component of the inductive loop impedance caused by a passing vehicle. These innovations result in high selective classification system, which utilizes over a dozen vehicle classes. The evaluation of the proposed approach was carried out for good vehicles consisting of 2-axle tractor and a 3-axle semi-trailer.

SiDIVS: Simple Detection of Inductive Vehicle Signatures with a Multiplex Resonant Sensor

“…Modern inductive detectors of vehicle presence are digital because they provide more reliable, accurate, and precise measurements than analogue detectors. Although there exist ILDs measuring other types of variations in the coil, like impedance [ 22 ], currently, the majority of ILDs indirectly measure variations in inductance as indicated in Equation ( 1 ). These variations are caused by the presence of a vehicle in the detection area of the inductive loop, which produces a decrease of inductance.…”

“…Furthermore, due to the function not being fully multiplexed and to the use of the same frequencies in near loops, such development causes significant interferences between channels (also known as crosstalk ). The work in [ 22 ] also presents a very complex hardware with a detector that obtains inductive vehicle signatures by measuring changes in coil impedance, separating its real part (R) from its imaginary part (X). It uses an analogue hardware, which integrates a self-balanced bridge when no vehicles are present, and two synchronous demodulators for obtaining the R and X signatures corresponding to each vehicle.…”

A comparison of the properties of conditioning systems cooperating with the eddy-current inductive loop sensor

“…In the field of vehicle classification IL sensors are used in a number of ways [4,5,6] that largely depend on the output signal of the measurement channel, wherein the sensor is working [7]. A key element of this channel is the conditioning signal system which, apart from the sensor and the measured object (vehicle), influences the parameters of the output signal.…”

“…A key element of this channel is the conditioning signal system which, apart from the sensor and the measured object (vehicle), influences the parameters of the output signal. These signals can be then used for classification purposes [4,6]. However, it is not possible to use the signals from various systems for the same classification process.…”

New methods in the application of inertial and magnetic sensors in online pattern recognition problems

“…Two loops are needed for speed measurement, heading direction estimation, and vehicle classification. Classification is usually done using the estimated axle-count and vehicle length, which is computed using the measured speed and the detection length [71]. Some methods also exist which use only a single loop for classification [72][73].…”