Muhammad Haris Afzal

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This paper presents an algorithm for calibrating erroneous tri-axis magnetometers in the magnetic field domain. Unlike existing algorithms, no simplification is made on the nature of errors to ease the estimation. A complete error model, including instrumentation errors (scale factors, nonorthogonality, and offsets) and magnetic deviations (soft and hard(More)
Engineering and Technology Karachi in 2002. Before joining the University of Calgary, he worked as a research engineer for six years with NESCOM Pakistan in the field of avionics navigation and control systems. Professor Gérard Lachapelle holds a CRC/iCore Chair in Wireless Location in the Department of Geomatics Engineering at the University of Calgary(More)
Low cost magnetometers can be used for estimating the orientation with respect to the magnetic North. Although magnetometers work very well in clean magnetic environments like in the outdoors, they are strongly influenced by magnetic perturbations produced by manmade infrastructure in the indoors. Calibration techniques exist that can be used to compensate(More)
—Heading estimation plays an important role in pedestrian navigation applications. Although gyroscopes are considered to be the primary sensors for orientation estimation, the errors associated with these sensors require periodic updates from other sources. In case of small hand-held devices, these other sources are accelerometers for roll and pitch(More)
Most portable systems like smart-phones are equipped with low cost consumer grade sensors, making them useful as Pedestrian Navigation Systems (PNS). Measurements of these sensors are severely contaminated by errors caused due to instrumentation and environmental issues rendering the unaided navigation solution with these sensors of limited use. The overall(More)
Determining orientation with respect to a known reference plays an important role in almost all modes of navigation. As the sensors required for measuring magnetic field have found their way into portable navigation devices, researchers have started investigating their application to orientation estimation in different environments. Nevertheless, the(More)
Although the equations' derivation in our paper published in Sensors 2011 [1] is correct, a typo has been found in the summarizing Equations (48) and (49). The dot on the B in the skew matrix should be removed. Equations (48) and (49) should be corrected as:
In this work, the homotopy analysis method (HAM) is applied to solve the fourth-order parabolic partial differential equations. This equation practically arises in the transverse vibration problems. The proposed iterative scheme finds the solution without any discritization, linearization, or restrictive assumptions. Some applications are given to verify(More)
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