Vehicle Speed and Length Estimation Using Data from Two Anisotropic Magneto-Resistive (AMR) Sensors

Abstract

Methods for estimating a car’s length are presented in this paper, as well as the results achieved by using a self-designed system equipped with two anisotropic magneto-resistive (AMR) sensors, which were placed on a road lane. The purpose of the research was to compare the lengths of mid-size cars, i.e., family cars (hatchbacks), saloons (sedans), station wagons and SUVs. Four methods were used in the research: a simple threshold based method, a threshold method based on moving average and standard deviation, a two-extreme-peak detection method and a method based on the amplitude and time normalization using linear extrapolation (or interpolation). The results were achieved by analyzing changes in the magnitude and in the absolute z-component of the magnetic field as well. The tests, which were performed in four different Earth directions, show differences in the values of estimated lengths. The magnitude-based results in the case when cars drove from the South to the North direction were even up to 1.2 m higher than the other results achieved using the threshold methods. Smaller differences in lengths were observed when the distances were measured between two extreme peaks in the car magnetic signatures. The results were summarized in tables and the errors of estimated lengths were presented. The maximal errors, related to real lengths, were up to 22%.

A Novel Vehicle Detection Method Based on the Fusion of Radio Received Signal Strength and Geomagnetism

“…The algorithm principle of the traditional single magnetism-based method has been described deeply in the literature [5,19,20]. Generally, the vehicle existence detected based on the change in the magnetism is greater than a specific threshold, the vehicle leaving detection is based on the change in the magnetism is less than a specific threshold within a certain time window.…”

“…At present, there are various vehicle detection methods, such as inductance loop [2,3,4], geomagnetic sensor [5], microwave radar, infrared, video, etc. The video vehicle detector has the advantages of high detection accuracy, stability and reliability and widely used in the world.…”

Allocation Method for Mobile Charging Vehicles Based on the Spatial Charging Demand

“…As an intelligent optimization algorithm, the immune algorithm has favourable ability of seeking the global excellent result, which is suitable for multi-extreme value condition [17]- [19]. In combination with the feature of the immune algorithm, the resident spot and the amount of the MCV are optimized by the immune algorithm, which takes the best service rate and coverage into consideration.…”

Practical Methods for Vehicle Speed Estimation Using a Microprocessor-Embedded System with AMR Sensors

“…Speed was evaluated using four methods: method 1—the location of the maximum value of the cross-correlation function in the time domain [ 15 ], method 2—the location of the minimum value of the SAD function in the time domain [ 9 ], method 3—the location of the maximum value of the circular convolution of two sequences (using DFT and IDFT algorithms) [ 5 , 16 ], method 4—the difference in gravity (mass) centers of two discrete signals [ 17 ]. …”

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