Browsing by Subject "Phong illumination model"

Now showing 1 - 4 of 4

Open Access
Improved range estimation using simple infrared sensors without prior knowledge of surface characteristics
(Institute of Physics Publishing Ltd., 2005) Yüzbaşioglu, Ç.; Barshan, B.
This paper describes a new method for position estimation of planar surfaces using simple, low-cost infrared sensors. The intensity data acquired with infrared sensors depend highly on the surface properties and the configuration of the sensors with respect to the surface. Therefore, in many related studies, either the properties of the surface are determined first or certain assumptions about the surface are made in order to estimate the distance and the orientation of the surface relative to the sensors. We propose a novel method for position estimation of surfaces with infrared sensors without the need to determine the surface properties first. The method is considered to be independent of the type of surface encountered since it is based on searching for the position of the maximum value of the intensity data rather than using absolute intensity values which would depend on the surface type. The method is verified experimentally with planar surfaces of different surface properties. An intelligent feature of our system is that its operating range is made adaptive based on the maximum intensity of the detected signal. Three different ways of processing the intensity signals are considered for range estimation. The absolute mean range error for the method resulting in the lowest errors is 0.15 cm over the range from 10 to 50 cm. The cases where the azimuth and elevation angles are nonzero are considered as well. The results obtained demonstrate that infrared sensors can be used for localization to an unexpectedly high accuracy without prior knowledge of the surface characteristics.
Open Access
Improved range estimation using simple infrared sensors without prior knowledge of surface characteristics
(2004) Yüzbaşıoğlu, R. Çağrı
This thesis describes a new method for range estimation using low-cost infrared sensors. The intensity data acquired with infrared sensors depends highly on the surface properties and the con guration of the sensors with respect to the surface. Therefore, in many related studies, either the properties of the surface are determined rst or certain assumptions about the surface are made in order to estimate the distance and the orientation of the surface relative to the sensors. We propose a novel method for position estimation of surfaces with infrared sensors without the need to determine the surface properties rst. The method is relatively independent of the type of surface encountered since it is based on searching the maximum value of the intensity rather than using absolute intensity values for a given surface which would depend on the surface type. The method is veri ed experimentally with planar surfaces of di erent surface properties. An intelligent feature of our system is that its operating range is made adaptive based on the intensity of the detected signal. Three di erent ways of processing the intensity signals are considered for range estimation. The overall absolute mean error in the range estimates has been calculated as 0.15 cm in the range from 10 to 50 cm. The cases where the azimuth and elevation angles are nonzero are considered as well. The results obtained demonstrate that infrared sensors can be used for localization to an unexpectedly high accuracy without prior knowledge of the surface characteristics.
Open Access
A new method for range estimation using simple infrared sensors
(IEEE, 2005-08) Yüzbaşıoǧlu, Çağrı; Barshan, Billur
We describe a new method for position estimation of planar surfaces using simple, low-cost infrared (IR) sensors. The intensity data acquired with IR sensors depends highly on the surface properties and the configuration of the sensors with respect to the surface. Therefore, in many related studies, either the properties of the surface are determined first or certain assumptions about the surface are made to estimate the distance and the orientation of the surface relative to the sensors. We propose a novel method for position estimation of surfaces with IR sensors without the need to determine the surface properties first. The method is considered to be independent of the type of surface encountered since it is based on searching the position of the maximum value of the intensity data rather than using absolute intensity values. The method is verified experimentally with planar surfaces of different surface properties. An intelligent feature of our system is that its operating range is made adaptive based on the maximum intensity of the detected signal. The absolute mean range error for the method resulting in the lowest errors is 0.15 cm over the range from 10 to 50 cm. The cases where the azimuth and elevation angles are nonzero are considered as well. The results obtained demonstrate that IR sensors can be used for localization to an unexpectedly high accuracy without prior knowledge of the surface characteristics. © 2005 IEEE.
Open Access
Rule-based target differentiation and position estimation based on infrared intensity measurements
(SPIE, 2003) Aytaç, T.; Barshan, B.
This study investigates the use of low-cost infrared sensors in the differentiation and localization of target primitives commonly encountered in indoor environments, such as planes, corners, edges, and cylinders. The intensity readings from such sensors are highly dependent on target location and properties in a way that cannot be represented in a simple manner, making the differentiation and localization difficult. We propose the use of angular intensity scans from two infrared sensors and present a rule-based algorithm to process them. The method can achieve position-invariant target differentiation without relying on the absolute return signal intensities of the infrared sensors. The method is verified experimentally. Planes, 90-deg corners, 90-deg edges, and cylinders are differentiated with correct rates of 90%, 100%, 82.5%, and 92.5%, respectively. Targets are localized with average absolute range and azimuth errors of 0.55 cm and 1.03 deg. The demonstration shows that simple infrared sensors, when coupled with appropriate processing, can be used to extract a significantly greater amount of information than they are commonly employed for.