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Article
Implementation of Mobile Robot’s Navigation using SLAM based on Cloud Computing

Authors: H.M. Hasan --- T.H. Mohammed
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 6 Part (A) Engineering Pages: 634-639
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

This paper is concerned with the implementation of EKF-SLAM (Extended Kalman Filter- Simultaneous Localization and Mapping) algorithm using a cloud computing architecture based on ROS (Robot Operating System). The localization and mapping is essential step to navigate a mobile robot in unknown environment. The implemented EKF-SLAM has used a landmark that sensed using IR Emitter sensor provided by the Kinect camera to update a map of the environment and simultaneously estimate the robot’s position and orientation within the map. The implementation was done using three parts. The first one was the TurleBot Mobile robot with the Kinect camera, which was simulated in Gazebo environment. The second part was the EKF-SLAM running under the MATLAB to generate the Map and Location data. The third part was the ROS Master node, which runs on the cloud to enable part one and two to communicate using topics. The scan data from Kinect camera and the location data from the odometer is transferred from the first part to the second part through ROS Master node after impaired with zero mean Gaussian noise . Then the second part performs EKF-SLAM and transmit the corrections to the first part through the ROS Master node as well.

Keywords

Cloud Computing --- EKF --- Gazebo --- Kinect --- Kinect


Article
Performance Comparison of Two Estimators for Two-Phase Permanent Magnet Synchronous Motor
مقارنة اداء مخمنين لمحرك تزامني ذو طورين وذات مغانيط دائمية

Author: Dr. Amjad J. Humaidi . امجد جليل حميد
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2011 Volume: 14 Issue: 1 Pages: 46-60
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

This paper presents and compares the performance of two Kalman filter schemes, the discrete extended Kalman filter (EKF) and unscented Kalman filter (UKF) for estimating the states (winding currents, rotor speed and rotor angular position) of two-phase Permanent Magnet Synchronous Motor (PMSM). Estimating the states of the system is performed by propagating the mean and covariance of the state distribution. For linear systems, the general recursive Kalman filter algorithm based on MMSE (minimum mean squared error) is the straightforward estimation technique to be implemented. For nonlinear systems, extended Kalman filter (EKF) is considered to be the best nonlinear estimator. The EKF is based on linearizing the state and output equations at every sampling instant. Therefore, this estimator requires continuously computation of the Jacobian matrix. The unscented Kalman filter (UKF) is based on implementation of the unscented transformation (UT) to the nonlinear state distribution (motor model). The UT uses the intuition that it is easier to approximate a probability distribution than it is to approximate an arbitrary nonlinear function or transformation. Apply this intuition to motor model, a set or cloud of points are generated around each state of motor model with specified sample mean and sample covariance. The nonlinear function (PMSM model) is applied to each of these points in turn to yield a transformed sample, and the predicted mean and covariance are calculated from the transformed sample. Based on predicted mean and covariance the UKF recursive algorithm can be developed. The performance comparisons are based on standard deviation estimation errors of both estimators and the time computation effort required execute the algorithms of both filters. The simulated results show that the UKF gives best estimates at motor low speed, while its estimation performance degrade at high motor speed. On the other hand, the EKF shows bad estimation characteristics at low frequency and it yields good estimates at high source frequency. However,, the EKF algorithm keeps lower time computation effort over wide range of rotor speed than that required to execute the UKF software for the same range of source frequency. The PMSM motor model and the algorithms of both filters are built in Matlab package using S-function capability and scalar control strategy are used to account for constant stator magnetizing flux.

يقدم البحث نموذجين من مرشحات كالمان ((Kalman Filters؛ وهما مرشح كالمان المعدل (Extended Kalman Filter) ؛ و((unscented Kalman filter وذلك لتخمين متغيرات المنظومة (states) وتشمل تيارات ملفات المجال، وزاوية والسرعة الزاوية للجزء الدوار (rotor). يعتمد مرشح كالمان المعدل في تخمين المتغيرات على تحويل ألانموذج اللاخطي الى أنموذج خطي. لذلك من الضروري حساب مصفوفة جاكوبين (Jaccobian Matrix) في كل لحظة زمنية. بينما يعتمد ((unscented Kalman filter على توليد عينات من النقاط بطريقة معينة يمكن استخدامها لغرض حساب المتوسط الحسابي (mean) والتباين ((covariance للمتغيرالعشوائي ذو توزيع ((Gaussian، حيث يتم تمرير هذه النقاط بالانموذج اللاخطي للمنظومة وايجاد، مرة اخرى، المتوسط الحسابي (mean) والتباين ((covariance لناتج خرج هذه النقاط لدرجة دقة تصل الى حدين فقط من متوالية تيلر (Taylor series). اثبت النتائج ان (UKF) يتميز باداء عالي للتخمين في حالة السرع الواطئة للجزء الدوار، بينما يتفوق اداء (EKF) في حالة السرع العالية للمحرك التزامني. وكذلك فان الزمن المستغرق لتنفيذ خوارزمية (EKF) هي اقل من الزمن المطلوب لتنفيذ خوارزمية (UKF) ولجميع مديات السرع للمحرك التزامني


Article
Sensorless Speed Estimation of Permanent Magnet Synchronous Motor Using Extended Kalman Filter

Authors: Hala W. Khalid --- Dr.Farazdaq R. Yasien
Journal: IRAQI JOURNAL OF COMPUTERS,COMMUNICATION AND CONTROL & SYSTEMS ENGINEERING المجلة العراقية لهندسة الحاسبات والاتصالات والسيطرة والنظم ISSN: 18119212 Year: 2018 Volume: 18 Issue: 1 Pages: 64-81
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

This paper presents a new approach in the modeling and the design of sensorless control method for the Permanent Magnet Synchronous Motor (PMSM) based on the use of the Extended Kalman Filter (EKF). The fourth order EKF is proposed to estimates the states: motor speed ω, rotor angular position, θ and the currents from the measured currents and voltages. The linearization of the nonlinear PMSM model is done in the α_β coordinate system to perform the operation of the EKF.The three phases Space Vector Pulse Width Modulation (SVPWM) inverter usually implemented as a part of the Field Oriented Control (FOC) strategy which has become a standard in the control of PMSM.


Article
State Estimation of Direct Field Orientation Control Induction Motor Drive by Using Kalman Filter
تخمين المعطيات للمحرك الحثي ذو سيطرة توجية المجال المغناطيسي المباشر بأستخدام مرشحات الكالمان

Author: Mohammed Khalil Hussain
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2012 Volume: 30 Issue: 15 Pages: 2725-2745
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Field oriented control (FOC) method of an induction motor (IM), allows high performance speed and torque response to be achieved from an induction motor. The present work selects the direct field orientation control induction motor (DFOCIM) as an effective method for eliminating the coupling effect between torque and flux. In the present work, two schemes of estimators have been used, standard kalman filter (SKF) and Extended kalman filter (EKF) for estimating stator current, rotor flux and rotor speed. The performance comparison is based on evaluation of estimation error of both estimators. The performances of suggested estimators are assessed in terms of tracking performance and noise rejection capability.

تحقق سيطرة توجيه المجال المغناطيسي الاداء العالي لاستجابة السرعة والعزم في المحرك الحثي . في العمل الحالي تم اختيار سيطرة توجيه المجال المغناطيسي المباشر كأحد الطرق الفعالة لازالة التاثير المتبادل بين العزم والفيض المغناطيسي للمحرك الحثي وتم استخدام نوعين من التخمين , Standard Kalman Filter (SKF) و Extended Kalman Filter (EKF) لتخمين تيار الجزء الثابت وفيض الجزء الدوار وسرعة الجزء الدوار للمحرك الحثي : وتم مقارنة الاداء بتقدير الخطا للنوعين وتم تقييم الاداء من ناحية تتبع الاداء وكذلك قابلية رفض الضوضاء.

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