Mohammad Amin Jarrah

Development and calibration of low cost MEMS IMU for UAV applications

In this paper, an affordable and reliable low-cost inertial measurement unit (IMU) is designed using commercial off-the-shelf (COTS) components. Micro electro-mechanical systems (MEMS) accelerometers and rate-gyros are used, and a methodology for calibrating the resulting IMU is developed when the precise orientation of the IMU is unknown. The proposed methodology requires no precise mechanical platform for the accelerometer while as simple rotating table is utilized for the rate-gyros calibration. The proposed calibration methods utilize the fact that ideally the norm of the measured output of the accelerometer and gyro cluster is equal to the magnitude of applied force and rotational velocity, respectively. Least squares method is used to evaluate the accelerometers and gyros model coefficients.

Attitude stabilization of quadrotor UAV using Backstepping Fuzzy Logic & Backstepping Least-Mean-Square controllers

Inspired by advantages of backstepping control theory combined with rule-based control technique and with least-mean-square algorithm, this paper introduces the Backstepping Fuzzy Logic controller (BFL) and Backstepping Least Mean Square controller (BLMS) as new approaches to control the attitude stabilization of quadrotor UAV. In this paper a recursive Lyapunov function is introduced to ensure the stability around a fixed set-point using backstepping control algorithm. The BFL controller utilizes the advantage of fuzzy logic to schedule the backstepping controller parameters. This resulted in improved performance compeered with that achieved by backstepping controller alone. On the other hand, the BLMS controller is used to minimize the control efforts by finding the parameters of backstepping controller which provide minimum control efforts to the system. Finally, a comparison between Backstepping, BFL and BLMS controllers are presented. BLMS controller suffered from a slow time response while having reduced control effort when compared with the BFL controller. Combined performance of the BFL controller was superior to the backstepping or BLMS controller.

Integrated simulation platform for indoor quadrotor applications

In this paper, an integrated simulation platform is developed for indoor quadrotor applications. The simulation platform mainly consists of two subsystems, the controller subsystem; the other subsystem is an indoor interactive environment. The two integrated subsystems can be highly deployed in quadrotor systems development cycle and validation of different algorithms for indoor navigation. Moreover, the simulation platform has visualization capability and tuning flexibility. These features provide the necessary ability to implement and inspect the developed algorithm in different scenario conditions before implementing them for indoor applications.

Optimization of Intelligent Approach for Low-Cost INS/GPS Navigation System

Due to the inherent highly nonlinear vehicle state error dynamics obtained from low-cost inertial navigation system (INS) and Global Positioning System (GPS) along with the unknown statistical properties of these sensors, the optimality/accuracy of the classical Kalman filter for sensor fusion is not guaranteed. Therefore, in this paper, low-cost INS/GPS measurement integration is optimized based on different artificial intelligence (AI) techniques: Neural Networks (NN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) architectures. The proposed approaches are aimed at achieving high-accuracy vehicle state estimates. The architectures utilize overlapping windows for delayed input signals. Both the NN approaches and the ANFIS approaches are used once with overlapping position windows as the input and once with overlapping position and velocity windows as the input. Experimental tests are conducted to evaluate the performance of the proposed AI approaches. The achieved accuracy is presented and discussed. The study finds that using ANFIS, with both position and velocity as input, provides the best estimates of position and velocity in the navigation system. Therefore, the dynamic input delayed ANFIS approach is further analyzed at the end of the paper. The effect of the input window size on the accuracy of state estimation is also discussed.

Intelligent fault detection and fusion for INS/GPS navigation system

In this paper, an Adaptive Neuro-Fuzzy Inference System (ANFIS) is proposed for low-cost navigation of ground vehicles. The ANFIS structure is proposed for fusing the measurements of the Global Positioning System (GPS) and inertial measurement unit (IMU). Low-cost GPS receivers provide the position and velocity of the vehicle at a lower rate than the IMU sampled vehicle dynamics. Additionally, the GPS measurements might be missed/delayed due to receivers inability to lock on the signal or due to obstruction from neighboring vehicles or infrastructures. Therefore, the variable delay between the IMU and GPS signals is selected as an additional input to the ANFIS architecture. The performance of the proposed ANFIS architecture is demonstrated through experimental results. The instrumentation system used in this experiment consists of a microcontroller system, a GPS receiver, and an IMU.

Adaptive Integral Backstepping Controller for an autonomous rotorcraft

in this paper, a new control approach is proposed using Adaptive Integral Backstepping Controller (AIBC) for controlling an autonomous rotorcraft. The recursive Lyapunov methodology in the backstepping technique will ensure the system stability, the integral action will increase the system robustness against disturbances and model uncertainties, and the adaptation law will estimate the modeling errors caused by assumptions in simplifying the complexity of the helicopter model. In addition, a Lyapunov-based Velocity Controller (LVC) is introduced to work side by side with the AIBC for hover and like-hover control. Simulation results show that the proposed algorithms are capable of controlling the nonlinear helicopter model, while showing robustness against disturbances and model uncertainties.

Low-cost, high-accuracy, state estimation for vehicle collision prevention system

In this paper, a low-cost navigation system with high integrity and reliability is proposed for enhancing highway traffic safety in adverse weather situations, such as a foggy or rainy weather. A high-integrity, 15-state, estimation filter is proposed to obtain a high accuracy state estimate. The filter utilizes a vehicle velocity constraint measurement to enhance the accuracy of the estimate. Two estimations filters, the Kalman filter (KF) and the information filter (IF), are designed and compared to obtain the estimate of the vehicle state. An instrumentation system that consists of a microcontroller, a GPS receiver, an IMU, encoders, and a Zigbee transceiver is constructed. The microcontroller provides a vehicle navigation solution at 50 Hz by fusing the measurements of the IMU, the GPS receiver and the digital compass using the proposed filter design. Experimental tests, using the proposed system, are conducted and the obtained results are presented. These results are processed with and without the velocity constraints. The estimation accuracy improvement with the addition of the velocity constraints is demonstrated. Also, results of a static test are used to assess the accuracy of the low-cost navigation systems against a commercial solution.

Incidence and prognosis of stent thrombosis following percutaneous coronary intervention in Middle Eastern patients: The First Jordanian Percutaneous Coronary Intervention Registry (JoPCR1).

BACKGROUND The incidence, risk factors, and outcome of stent thrombosis (ST) after percutaneous coronary intervention (PCI) in Middle Eastern patients are largely unknown. OBJECTIVE To determine the incidence, risk factors and outcome in our population. DESIGN Retrospective study of a prospective multicenter registry of consecutive patients who underwent PCI between January 2013 and February 2014 (JoPCR1). SETTING 12 tertiary care centers in Amman and Irbid, Jordan. PATIENTS AND METHODS We collected clinical baseline and follow-up data. MAIN OUTCOME MEASURES Incidence of stent thrombosis. RESULTS The mean (standard deviation) age of patients (n=2426) was 59.0 (10.1) years and 20.6% were women. Stents (n=3038) were drug eluting (89.6%), bare metal (9.4%) or bioabsorbable (1.0%). After 1 year, 47 patients (1.97%) had ST, including 44 (94%) definite and 3 (6%) probable ST. Patients who had ST presented with sudden death (n=6; 12.2%) or with a nonfatal event (n=43; 87.8%). Nonfatal events included non-ST-segment elevation acute coronary syndrome (26; 53%), acute ST segment elevation myocardial infarction (n=15; 31%) or heart failure (n=2; 4.1%). ST was associated with significantly higher one-month (22.0% vs. 0.7%) and one-year (12.3% vs. 0.73%) mortality rates compared with patients who did not have ST (P<.001). ST patients were younger (mean age 52.9 years vs. 58.4 years), had heart failure (64% vs. 18%), left ventricular ejection fraction (LVEF) <45% (36% vs. 13%), ST-segment deviation (70% vs. 48%), and elevated cardiac biomarkers blood levels (62% vs. 40%). In the multivariate analysis, the only factor that was significantly associated with ST was the heart failure (OR = 3.5, 95% confidence interval: 1.8, 6.6; P<.0001). CONCLUSIONS The incidence of ST was not different from that in other regions and was associated with an increased one-year mortality. Younger age, heart failure, low LVEF, ST-segment deviation, and elevated blood levels of cardiac biomarkers were predictors of ST. LIMITATIONS Possible selection bias, recall bias, and missing or incomplete information. The majority of patients were lost to follow up after the 6th month. The registry may not fully represent PCI practice and outcome in all areas in the country or region.

Outcomes of Middle Eastern patients undergoing percutaneous coronary intervention: The primary analysis of the First Jordanian PCI Registry

Aim: This is a prospective multicenter registry designed to evaluate the incidence of adverse cardiovascular events in Middle Eastern patients undergoing percutaneous coronary interventions (PCI). The registry was also designed to determine the predictors of poor outcomes in such patients. Methods and Results: We enrolled 2426 consecutive patients who underwent PCI at 12 tertiary care centers in Jordan between January 2013 and February 2014. A case report form was used to record data prospectively at hospital admission, discharge, and 12 months of follow-up. Mean age was 56 ± 11 years, females comprised 21% of the study patients, 62% had hypertension, 53% were diabetics, and 57% were cigarette smokers. Most patients (77%) underwent PCI for acute coronary syndrome. In-hospital and 1-year mortality rates were 0.78% and 1.94%, respectively. Definite or probable stent thrombosis occurred in 9 patients (0.37%) during hospitalization and in 47 (1.94%) at 1 year. Rates of target vessel repeat PCI and coronary artery bypass graft surgery at 1 year were 3.4% and 0.6%, respectively. The multivariate analysis revealed that cardiogenic shock, congestive heart failure, ST-segment deviation, diabetes, and major bleeding were significantly associated with higher risk of 1-year mortality. Conclusions: In this first large Jordanian registry of Middle Eastern patients undergoing PCI, patients treated were relatively young age population with low in-hospital and 1-year adverse cardiovascular events. Certain clinical features were associated with worse outcomes and may warrant aggressive therapeutic strategies.