Multifrequency Vector Measurement System for Reliable Vehicle Magnetic Profile Assessment

Abstract

This paper describes the design and the performance of simultaneous, multifrequency impedance measurement system for four inductive-loop (IL) sensors which have been developed for vehicle parameters measurement based on vehicle magnetic profile (VMP) analysis. Simultaneous impedance measurement on several excitation frequencies increases the VMP measurement reliability because typical electromagnetic interferences (EMI) are narrowband, and should not simultaneously affect, in the same way, all measurement bands that are spread in the frequency, i.e., it is expected that at least one measurement band is disturbance-free. The system consists of two standard and two slim IL sensors, specially designed and installed, the analogue front-end, and an industrial computer with digital-to-analogue and analogue-to-digital converters accessed via field-programmable gate array (FPGA). The impedance of the IL sensors is obtained by vector measurement of voltages from auto-balancing bridge (ABB) front-end. Complex voltages are demodulated from excitation frequencies with FIR filters designed with the flat-top windows. The system is capable of delivering VMPs in real-time mode, and also storing voltages for off-line postprocessing and analysis. Field distributions and sensitivities of slim and standard IL sensors are also discussed. Field test confirmed assumed increased reliability of VMP measurement for proposed simultaneous multifrequency operational mode.

Load Estimation of Moving Passenger Cars Using Inductive-Loop Technology

“…Digital processing is carried out using an industrial NI-PXI computer with a data acquisition card containing an FPGA module. Detailed technical information about the IL sensors construction and the implementation of the MFIM method is given in [ 24 ]. Compared to [ 24 ], the following significant changes have been additionally applied.…”

“…MFIM has also been used to detect and size DNA fragments [ 23 ]. However, as recent research shows, the MFIM system for IL sensors provides more reliable signals for various purposes [ 24 , 25 ]. The MFIM system output signal is called vehicle magnetic profile (VMP).…”

“…This relation originates from the dependence of the passenger vehicle clearance value on the vehicle load mass and finally the VMP. It is also highlighted that the slim IL sensors [ 24 , 25 ] are better suited for the task than the wide IL sensors. They allow the building of a system for estimating the load mass of a passenger vehicle within a maximum error of around 30 kg and approximate estimation of the number of passengers under the assumption of an average passenger mass, e.g., 70 kg.…”

Electronics for Sensors

“…This Special Issue contains a selection of 16 papers covering photomultiplier tubes and silicon photomultipliers (PMTs and SiPMs) interfaces and applications [1][2][3], techniques for monitoring radiation levels [4,5], electronics for biomedical applications [6][7][8], design and applications of time-to-digital converters [9][10][11], interfaces for image sensors [12,13] and general-purpose theory and topologies for electronic interfaces [14][15][16].…”

“…In [ 14 ], Zhang et al propose a modeling of the temperature hysteresis of inertial navigation systems used in aerial navigation and a novel compensation methodology. Marszalek and Duda, in [ 15 ], present the design and performances of a simultaneous and multifrequency impedance measurement system used with four inductive loop sensors for detecting vehicles’ magnetic profile. Finally, in [ 16 ], Pettinato et al propose a current reference circuit based on the LT199x amplifier, which has increased accuracy and linearity with respect to commonly adopted op-amp-based solutions.…”