scholarly journals Inductive Loop Axle Detector based on Resistance and Reactance Vehicle Magnetic Profiles

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2376 ◽  
Author(s):  
Zbigniew Marszalek ◽  
Tadeusz Zeglen ◽  
Ryszard Sroka ◽  
Janusz Gajda

The article presents a measurement system that captures two components of a motor vehicle’s magnetic profile, which are associated with the real and imaginary part of the impedance of a narrow inductive loop sensor. The proposed algorithm utilizes both components of the impedance magnetic profile to detect vehicle axles, including lifted axles. Accuracies of no less than 71.8% were achieved for vehicles travelling with a lifted axle, and no less than 98.8% for other vehicles. The axle detection accuracy was determined during a series of experiments carried out under normal traffic conditions, using profile analysis, video footage and reference signals from an axle load detector on a total of 4000 vehicles.

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4933 ◽  
Author(s):  
Zbigniew Marszalek ◽  
Krzysztof Duda

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.


Author(s):  
Robert L. Bertini ◽  
Aaron M. Myton

To improve freeway modeling and operations, it is important to understand how traffic conditions evolve in both time and space. The widespread availability of freeway sensor data makes detailed operational analysis possible in ways that were not available in the past. This study, inspired by several other studies of a 6-mi segment of Interstate 405 in Orange County, California, describes the evolution of traffic conditions over one morning peak period by using inductive loop detector data, including vehicle count and lane occupancy measured at 30-s intervals. With cumulative curves of vehicle count and occupancy, transformed in ways that enhanced their resolution, 10 bottleneck activations were identified in time and space over one morning peak period. At bottleneck activation, queue propagation was observed in generally predictable ways. Bottleneck outflows were carefully measured only while the bottlenecks were active, that is, while queued conditions persisted upstream and unqueued (freely flowing) conditions prevailed downstream. When bottlenecks were activated immediately following freely flowing conditions, outflow reductions were observed at queue formation. These reductions were consistent with those in previous studies. The study was limited in that only one day's data were analyzed and ramp data were not available on the day analyzed. Future research will include further analysis of the same site by using more recent data now that ramp counts are available in the California Performance Measurement System database. Understanding the mechanisms that lead to bottleneck activation is a critical step toward improving the understanding of how freeways function and is necessary for addressing operational issues. This clear understanding provides a foundation for determining ramp metering rates and addressing the freeway characteristics that cause bottlenecks to form.


Author(s):  
Anan Banharnsakun ◽  
Supannee Tanathong

Purpose Developing algorithms for automated detection and tracking of multiple objects is one challenge in the field of object tracking. Especially in a traffic video monitoring system, vehicle detection is an essential and challenging task. In the previous studies, many vehicle detection methods have been presented. These proposed approaches mostly used either motion information or characteristic information to detect vehicles. Although these methods are effective in detecting vehicles, their detection accuracy still needs to be improved. Moreover, the headlights and windshields, which are used as the vehicle features for detection in these methods, are easily obscured in some traffic conditions. The paper aims to discuss these issues. Design/methodology/approach First, each frame will be captured from a video sequence and then the background subtraction is performed by using the Mixture-of-Gaussians background model. Next, the Shi-Tomasi corner detection method is employed to extract the feature points from objects of interest in each foreground scene and the hierarchical clustering approach is then applied to cluster and form them into feature blocks. These feature blocks will be used to track the moving objects frame by frame. Findings Using the proposed method, it is possible to detect the vehicles in both day-time and night-time scenarios with a 95 percent accuracy rate and can cope with irrelevant movement (waving trees), which has to be deemed as background. In addition, the proposed method is able to deal with different vehicle shapes such as cars, vans, and motorcycles. Originality/value This paper presents a hierarchical clustering of features approach for multiple vehicles tracking in traffic environments to improve the capability of detection and tracking in case that the vehicle features are obscured in some traffic conditions.


Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6329
Author(s):  
Ruijun Li ◽  
Yongjun Wang ◽  
Pan Tao ◽  
Rongjun Cheng ◽  
Zhenying Cheng ◽  
...  

Laser beam drift greatly influences the accuracy of a four degrees of freedom (4-DOF) measurement system during the detection of machine tool errors, especially for long-distance measurement. A novel method was proposed using bellows to serve as a laser beam shield and air pumps to stabilize the refractive index of air. The inner diameter of the bellows and the control mode of the pumps were optimized through theoretical analysis and simulation. An experimental setup was established to verify the feasibility of the method under the temperature interference condition. The results indicated that the position stability of the laser beam spot can be improved by more than 79% under the action of pumping and inflating. The proposed scheme provides a cost-effective method to reduce the laser beam drift, which can be applied to improve the detection accuracy of a 4-DOF measurement system.


2012 ◽  
Vol 600 ◽  
pp. 80-87
Author(s):  
Di Ming Lou ◽  
Yi Jue Wang ◽  
Zhi Yuan Hu ◽  
Pi Qiang Tan

An experimental investigation was conducted using PEMS(portable emissions measurement system) to compare on-road emission characteristics of passenger cars fueled with several butanol-gasoline blends including a 10% and 20% butanol-gasoline blend (by volume) to that of gasoline. It was found that the higher the proportion of butanol blends in gasoline is the lower the emissions of CO, CO2, unburned hydrocarbons exhibited, while the emission level of NOx is just the opposite. Meanwhile, the emissions of gasoline passenger cars are related with both the traffic conditions and the vehicle speed. Thus, using butanol-gasoline blend fuel as well as improving the traffic conditions is important to lower the emissions of cars so that they are useful to environmental protection to a certain degree.


2013 ◽  
Vol 390 ◽  
pp. 343-349 ◽  
Author(s):  
Jerzy Merkisz ◽  
Pawel Fuc ◽  
Piotr Lijewski ◽  
Andrzej Ziolkowski

The paper describes the influence of the start-stop system on the exhaust emissions and fuel consumption. The tests were performed for two vehicles. The first one was a vehicle designed specifically to operate in city conditions. It was fitted with a gasoline engine of the displacement of 0.9 dm3 and maximum power output of 63.7 kW. The other vehicle was an SUV (Sports Utility Vehicle) fitted with a diesel engine of the displacement of 3.0 dm3. The measurements of the exhaust emission were carried out on the same route under actual traffic conditions. For the tests a portable exhaust emissions analyzer from the PEMS group SEMTECH DS was used (PEMS Portable Emissions Measurement System).


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