Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Fachhochschule Lausitz, Senftenberg Systems Engineering MASTER THESIS SAMPATH KUMAR UPPU (Matriculation Nr ) Supervisors: Prof. Dr.-Ing. E. Stein, FH Lausitz, Senftenberg Dr. H. Grüger Fraunhofer Institute for Photonic Microsystems, Dresden Prof. Dr.-Ing. B. K. Glück FH Lausitz, Senftenberg

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Contents  Introduction  Problem definition  Importance of this thesis work  Measurement of Earth’s field by using fluxgate sensor  Theoretical explanation  Advantages of fluxgate sensor  Experimental Set-up and measurement procedure  Measurement results  Comparison of vehicle signatures and equipotential lines  Interpretations of the results  Discussions  Conclusion  Future prospects

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Problem Definition:  With the increase of traffic on the roads the current traffic detection systems(Inductive loops) which are placed just below the earth‘s surface are not reliable.  Finding the appropriate vehicle recognition system. Aim of the Project:  The fluxgate sensor implementation in traffic detection system.  Finding the the appropriate sensor location and its direction of placement.

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Earth’s magnetic fieldThe earth’s magnetic field vector

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Vehicle disturbance in Earth‘s field: Ferrous object disturbance in uniform field:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Comparison of different magnetic elements with their operational range:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Comparison of low field magnetic sensors with the same resolution:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Sensor Type Measurement Range ResolutionCurrent Consumption Hall sensor±50mT0.1mT20mA Magnetoresistive sensor ± 10mT/ ±1mT200µT/20µT10mA IMS fluxgate sensor±200µT1µT35mA Comparison of different magnetic sensors:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Working Principle of Fluxgate Sensor:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Layout Diagram of FGS1/COB07:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Characteristics :  Two sensor axes are arranged in orthogonal directions.  The differential arrangement of fluxgate system filters out the even harmonics from the output signal.  With the differential arrangement the sensitivity will be twice as that of the single axis fluxgate sensor.  The output voltage is linear.  Low drift in sensitivity.  The excitation current required by ferromagnetic core to drive into saturationregion is 30-35mA.

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Advantages:  The sensor is not affected by weather conditions such as rain, fog, snow, wind etc., and dirt.  There is no problem to detect the vehicle even when the vehicle is projected into adjacent lane.  This sensor needs very low maintenance.  With this sensor both moving and standing vehicles can be detected.

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Experimental Set-up:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Measurement Procedure:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Offset measurement:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Measurement Results

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Measurement Results

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Measurement Results

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Comparison of magnitude field strength with respect to distance:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Magnitude variation for different depths: Z-40cm depth Z-80cm depth

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Z-120cm depth  The sensors in the middle(16cm, -16cm) are showing more deviation and which are away from the center are showing less deviation of the field.  This effect is beneficial when a sensor has to detect vehicles in a single lane of traffic with other lanes present. Magnitude variation for different depths:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Comparison of sensor signatures for different depths:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Comparison of sensor signatures for different depths:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Comparison of sensor signatures for different depths:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Comparison of sensor signatures for different depths:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Comparison of magnetic fields for a depth of 120cm:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Comparison of magnetic fields for a depth of 120cm:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Comparison of magnetic fields for a depth of 120cm:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Comparison of magnetic fields for a depth of 120cm:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Equipotential lines: Figure 21 Figure 22 Analysis of Equipotential lines: –Vehicle presence: Figure 24

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE  Signal distortion due to the 50Hz power line cycle  Magnetic noise(Barkhausen noise).  Resistance noise(long cable): Calculated by Nyquist.  The measurements are taken by passing the car in steps of 20cm over the sensors. The position accuracy is ±1cm.  The Passat may not be driven exactly in the middle of the ramp. The variation is ±2.5cm.  Forward and Backward measurements. Accuracy limitations in measurements:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Interpretations of the results: Overlapping of Passat on the signature:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Vehicle Direction:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Vehicle Detection: Positioning the sensor:

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Figure28 Advantage of taking Bz for Vehicle Detection: B-Magnitude=√ (B 2 x +B 2 y +B 2 z ) –To get the third-axis field the sensor is to be rotated by 90°.

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE  Sensors are to be placed symmetrically.  The waveforms at the outputs of the sensors are identical.  Vehicle’s velocity: Vehicle length calculation:  Velocity and the magnitude variation Vehicle classification: Discussions: Velocity measurement :

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Some applications of vehicle presence in daily life:  Car Wash Entry/Exit  Drive-through System  Loading Dock  Gate closing  Traffic Detection  Intelligent parking Lots  Toll Ways

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Conclusion: Achieved results:  Analysis of Bx, By, Bz, B-magnitude.  Drawing Equipotential lines.  Sensor which is very close: Earth’s field+ Remanence.  Appropriate depth for the proper signature of the vehicle is 100cm or 120cm.  Analysis of equipotential lines:  z-axis field is suitable for the vehicle detection.

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Correlation to Demands of Detection System  Noise correlation technique:  Extract the actual signal from the embedding  Differential arrangement of fluxgate system:  Twice the sensitivity  Power line cycle filter:  Noise is reduced  Signal to noise ratio is improved  With this method of measurement:  Vehicle signature is much accurate

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE Future Prospects:  Finding length of the vehicle.  Classification of vehicles.  In this project the magnetic field in x, y, z directions are measured and from those B-magnitude is calculated.  Analyzing the Earth’s magnetic field vector (  ) : Bx, By and Bz  Comparing the results with different vehicles.

Sampath Kumar, Uppu Investigation of Magnetic Pattern of Vehicles and Correlation to Demands of Detection Systems FH Lausitz/ SE THANK YOU FOR YOUR ATTENTION