- Cairo, Muhafazat al Qahirah, Egypt
Gamal Elnashar
Millitary Technical College, Electronic Engineering, Faculty Member
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In this paper, a comparative study between different PID tunning techniques is presented. The proposed techniques are applied to solve the formation configuration problem for a cooperative team of unmanned vehicles. The formation problem... more
In this paper, a comparative study between different PID tunning techniques is presented. The proposed techniques are applied to solve the formation configuration problem for a cooperative team of unmanned vehicles. The formation problem for the cooperative team is divided into two levels of control, one is the backstepping control technique for the stabilization of the team members positions as a higher controller. Simultaneously, PID controller receives the desired position to stabilize the attitude control as a lower controller to track the desired planning trajectories. The main contribution of this paper is the comparison between the different control approaches in tunning the PID gains to stabilize attitude control for the leader quadrotor. Simulation results present the assessment of the proposed PID control technique compared with different PID tuning approaches such as local optimal control, fraction order, Ziegler-Nichols and genetic algorithm. Moreover, disturbance rejection and white noise attenuation criterions are inspected to evaluate the ability of the proposed controllers to preserve the stability of the system.
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Formation configuration is one of the major intrinsic strategies used in cooperative Unmanned Air Vehicles field. In this paper, Backstepping-PID control technique for cooperative quadrotors unmanned aerial vehicles are developed to solve... more
Formation configuration is one of the major intrinsic strategies used in cooperative Unmanned Air Vehicles field. In this paper, Backstepping-PID control technique for cooperative quadrotors unmanned aerial vehicles are developed to solve the formation problem. The proposed controller is divided into couple of parts working together. Backstepping controller is used to stabilize the position control as a higher controller. Simultaneously, PID controller receives the desired position to stabilize the attitude control as a lower controller to track the desired planning trajectories. The main contribution of this paper is using Fraction Order Approach, and Local Optimal Approach to refine the PID lower controller gains. The tunning of the PID gains through the proposed PID tuning approaches guarantee the stabilization of the attitude control for all the team members. Simulation results present the success of the proposed PID tuning approaches in solving the formation problem for coopera...
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In this paper, we consider the problem of designing a MIMOFMRLC for multi-input multi-output (MIMO) systems that are highly nonlinear and possess a strong coupling effect between their states. It presents a challenging system to control.... more
In this paper, we consider the problem of designing a MIMOFMRLC for multi-input multi-output (MIMO) systems that are highly nonlinear and possess a strong coupling effect between their states. It presents a challenging system to control. The paper introduces analysis of the passive line of sight (LOS) stabilization system. The nonlinear dynamics of the system are first derived. An intelligent fuzzy controller is introduced. The fuzzy control presents a nonlinear control technique that compensates the system nonlinearity; hence, it is more appropriate to stabilize and control the system under consideration. The fuzzy controller is designed to decouple the relationship between the system state variables. The controller performance is verified through simulations and results. Such a controller possesses a learning mechanism that is able to form its rule-base by watching the system behavior. The learning mechanism utilizes a reference model that describes the desired performance. The design process of the controller and simulation results of implementing the controller to the system is introduced. Finally, comparative analysis between different developed controllers is conducted. It discusses the advantages and disadvantages of each control algorithm
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This paper seeks to investigate the calculation of the prediction angle of the fire control problem. An integrated prediction angle of fire control system including a movable gun and line-of-sight tracker was derived analytically.... more
This paper seeks to investigate the calculation of the prediction angle of the fire control problem. An integrated prediction angle of fire control system including a movable gun and line-of-sight tracker was derived analytically. Numerical methods developed over many years will be used to calculate the prediction angle components (lead, curvature correction, and jump correction). The most challenging computational problem associated with fire control has always been determined using projectile trajectory. Prediction equations of motion must be solved simultaneously to determine the location of the future point of impact. Because targets are small and move rapidly in three dimensions, a system of automatic computation and transmission of firing data to the gun had become necessary to the satisfactory solution of the fire control problem. In this paper, we will make use of the numerical theory to develop an accurate and efficient scheme for predicting the present and future position of a manoeuvring target.
This paper is devoted to studying both the global and local stability of dynamical neural networks. In particular, it has focused on nonlinear neural networks with perturbation. Properties relating to asymptotic and exponential stability... more
This paper is devoted to studying both the global and local stability of dynamical neural networks. In particular, it has focused on nonlinear neural networks with perturbation. Properties relating to asymptotic and exponential stability and instability have been detailed. This paper also looks at the robustness of neural networks to perturbations and examines if the related properties have been preserved. Circumstances for global and local exponential stability of nonlinear neural network dynamics have been studied. We mentioned that the local exponential stability of any equilibrium point of dynamical neural networks is equivalent to the stability of the linearized system around that equilibrium point. From this, some well-known and new sufficient conditions for local exponential stability of neural networks have been obtained. The Lyapunov’s procedure has been used to analyze the stability property of nonlinear dynamical systems and many outcomes have been combined and generalize...
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The target assignment for cooperative Unmanned aerial vehicles is a critical topic. Most target assignment approaches yield computational complexity when dealing with multiple UAVs. This work offers target assignment approaches and... more
The target assignment for cooperative Unmanned aerial vehicles is a critical topic. Most target assignment approaches yield computational complexity when dealing with multiple UAVs. This work offers target assignment approaches and resolves multiple UAVs problems by introducing a proposal of target assignment approaches. The main contribution of this work is solving the target assignment problem using optimal time approach and gain maximization approach in double stages. At the first stage, the urgently desired target to be fetched from the detected target group is selected by using the proposed objective function based on three attribute values of targets (threating weight - importance weight - separating distance). At the second stage, the proposed objective function is used and assign related UAVs for selected desired targets by considering the coverage factors, adaptive-limitation and constrains.
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Formation reconfiguration is one of the most significant subjects of the collaborative quadrotors unmanned aerial vehicles (UAVs). In this paper, a backstepping-PID (proportional-integral-derivative) controller is used with a group of... more
Formation reconfiguration is one of the most significant subjects of the collaborative quadrotors unmanned aerial vehicles (UAVs). In this paper, a backstepping-PID (proportional-integral-derivative) controller is used with a group of multiple collaborative quadrotors to track desired predesigned trajectory. The proposed backstepping-PID controller composed of two-loops of control. First loop is an external-loop for the higher-controller for position control, and the second loop is an internal-loop for the lower-controller for attitude control. The proposed controller uses a backstepping controller as a higher-controller and an PID controller as a lowercontroller. The main contribution in this paper is resolving the formation reconfiguration issue for the collaborative quadrotors in dynamic moving obstacles-loaded environment. Simulation results of collaborative quadrotors show that the proposed backstepping-PID controller enables formation reconfiguration of the collaborative quadr...
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Optimal human forearm trajectories structure was investigated using Optimal Regulator. First, the continuous dynamics of the human forearm were established on the basis of the relation between muscle torque and neural control signal and... more
Optimal human forearm trajectories structure was investigated using Optimal Regulator. First, the continuous dynamics of the human forearm were established on the basis of the relation between muscle torque and neural control signal and employed Riccati differential equation to obtain the optimal movement trajectory of the human forearm. The model and control of a human forearm is analyzed. In the advanced control of robotic manipulators, it is important for manipulators to track trajectories in a wide range of work place. If speed and accuracy is required, the control using conventional methods is difficult to realize because of the high nonlinearity of the robot system. In this work; we study the problem of human hand control carrying a mass. The equation of motion and the natural frequency of the forearm
Formation reconfiguration is one of the main strategies for cooperative quadrotors unmanned aerial vehicles (CQUAVs). This paper tackles the problem of formation reconfiguration for a team of CQUAVs in dynamic obstacles loaded... more
Formation reconfiguration is one of the main strategies for cooperative quadrotors unmanned aerial vehicles (CQUAVs). This paper tackles the problem of formation reconfiguration for a team of CQUAVs in dynamic obstacles loaded environment. A double layer backstepping control approach is utilized in a decentralized manner to control the formation of the CQUAVs team members while avoiding the dynamic obstacles. The first layer controls the position of the members with respect to the whole desired formation, and the second layer controls the attitude of the members. The main contribution in this work is applying the double layer backstepping control approach to solve the collision avoidance issues for a team of CQUAVs while keeping the desired formation in the presence of dynamic obstacles. The simulation results show the success of the proposed control approach in avoiding the dynamic obstacles guaranteeing the safety of the whole CQUAVs team members. Moreover, the proposed controller...
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There is an increasing trend towards object detection from aerial and satellite images. Most of the recent state-of the-art widely used object detection researches based on local features use the scanning of images by the sliding window.... more
There is an increasing trend towards object detection from aerial and satellite images. Most of the recent state-of the-art widely used object detection researches based on local features use the scanning of images by the sliding window. In this paper we propose an approach to localize the candidate objects by using the clustering of locations of the matched keypoints, this method has a benefits of minimizing the no of points to be processed by the classifier, and with more accuracy. In this paper, this approach is tested by SIFT and SURF local features detector and descriptor. This approach can be used as an object detection technique by itself or executed as a pre-step before apply the machine learning trained classifiers to achieve more precise results.
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A leader-follower structure is one of the main structures in the formation tactics for cooperative Unmanned aerial vehicles (UAVs). In this paper, the problem of a faulty leader in the leader-follower structure is tackled. A cyclic... more
A leader-follower structure is one of the main structures in the formation tactics for cooperative Unmanned aerial vehicles (UAVs). In this paper, the problem of a faulty leader in the leader-follower structure is tackled. A cyclic strategy is introduced to solve this problem guaranteeing the success of the whole squadron mission. The proposed strategy depends mainly on training all the members of the squadron to perform the leader activities through different time slice during the mission. The main contribution of this paper is introducing a new cyclic strategy capable in solving the faulty leader problem. The simulation results prove the success of the designed cyclic strategy in different scenarios guaranteeing the stability of the squadron formation in the transition time slice during the substitution of the leader. Moreover, the results show the success of the squadron in achieving the desired mission.
For any fire control system, performance improvement of Line Of Sight (LOS) stabilization subsystem enhances its mission capabilities. Designing controllers for a LOS stabilization subsystem, which is subjected to model uncertainty, is an... more
For any fire control system, performance improvement of Line Of Sight (LOS) stabilization subsystem enhances its mission capabilities. Designing controllers for a LOS stabilization subsystem, which is subjected to model uncertainty, is an interesting and challenging problem. In this paper different control techniques for LOS stabilization subsystem are used. The designed controllers are classical Proportional-Integral (PI) controller, genetically tuned PI controller, Linear Quadratic Regulator (LQR) controller, Linear Quadratic Gaussian (LQG) controller, and H∞ controller. Their performances in normal conditions are compared. They are also compared from robustness to model uncertainty point of view. Simulation results are used to determine the effectiveness of each controller in normal conditions and also when the system is subjected to model uncertainty. Keywords—Classical Proportional-Integral (PI) Controller; Genetically Tuned PI controller; Linear Quadratic Regulator (LQR) Contr...
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This paper presents a design and implementation of a real-time, vision-based target tracking system for unmanned aerial vehicle (UAV). The particle filter framework integrated with Lucas-Kanade optical flow technique to predict and... more
This paper presents a design and implementation of a real-time, vision-based target tracking system for unmanned aerial vehicle (UAV). The particle filter framework integrated with Lucas-Kanade optical flow technique to predict and correct the state of the moving target based on its dynamic and observation models. The optical flow estimates the corresponding feature points in the new image frame related to the previously detected/estimated points. The Maximum Likelihood Estimation SAmple Consensus (MLESAC) method is applied to estimate the ego-motion transformation matrix using the old and new sets of the feature points. This matrix is incorporated with the target dynamic model to give more accurate prediction results of its state. Two optimized types of features are extracted to build the target observation model. They include extended Haar-like rectangles and edge orientation histogram (EOH) features. A Gentle AdaBoost classifier is applied on these features to distinguish and cho...
The main focus of this paper is taken on the direct solution to the nonlinear autonomous underwater vehicle (AUV) dynamics including the performance and stability of a proposed controller without any restricting assumptions on the... more
The main focus of this paper is taken on the direct solution to the nonlinear autonomous underwater vehicle (AUV) dynamics including the performance and stability of a proposed controller without any restricting assumptions on the AUV's angles during the diving process. Because assumptions may cause severe result in practical applications, Six Degree of Freedom (6DOF) dynamic modeling has been taken into consideration. In fact, performance and stability of AUV has become the most important issue related to nonlinear control problems. In this paper a simulation for modeling and control of motion of an underwater vehicle in 6DOF is presented. Two main controllers are designed to control the depth and the heading of the underwater vehicle. Also, a pitch, yaw and roll attitude controllers are designed to keep the vehicle at a constant depth. Combining the useful properties of each one to improve the performance and stability of the overall controller. The resulting nonlinear control...
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Formation reconfiguration is one of the most important tactics used in the field of cooperative Unmanned Air Vehicles. In this paper, formation reconfiguration for a team of vertical takeoff and landing quadrotors is managed by a... more
Formation reconfiguration is one of the most important tactics used in the field of cooperative Unmanned Air Vehicles. In this paper, formation reconfiguration for a team of vertical takeoff and landing quadrotors is managed by a classical approach of proportional-integral-derivative (PID) controller. PID controller is designed to regulate the attitude and the altitude for every quadrotor of a cooperative team respecting the separating span and velocity constraints. PID controller results are compared with a backstepping controller developed for the same system. The mathematical model of the propositioned system is derived initially, and then a PID controller using simplex and genetic algorithms is designed qualifying the cooperative quadrotors to track the desired trajectories. Simulation results present the assessment of PID control strategy along with backstepping control strategy in different scenarios including proposal flight mission in obstacle-free surroundings, and obstacle...
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Planning and scheduling systems are needed to manage Earth-observing satellites for satisfying the optimum usage of the constellation's resources. This is a combinatorial optimization NP-hard problem that is solved in this paper... more
Planning and scheduling systems are needed to manage Earth-observing satellites for satisfying the optimum usage of the constellation's resources. This is a combinatorial optimization NP-hard problem that is solved in this paper using the constraint programming technique. The proposed system can deal with a heterogeneous constellation that consists of satellites with different maneuverability, placed in different orbits, and loaded with different payloads. The system's user can choose one of six optimization objectives, three of them were not used before, for constructing the satellites' mission plan. Searching within the system is performed using one of five different search algorithms. The system produces plans with different planning horizons ranging from one track to more than one month. The obtained results depict that the proposed system behaves, comparatively, in a perfect manner even when dealing with a complicated case study consisting of three satellites, 2,500 targets, and a one-month planning horizon.
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Planning and scheduling systems are needed to manage Earth-observing satellites for satisfying the optimum usage of the constellation's resources. This is a combinatorial optimization NP-hard problem that is solved in this paper using the... more
Planning and scheduling systems are needed to manage Earth-observing satellites for satisfying the optimum usage of the constellation's resources. This is a combinatorial optimization NP-hard problem that is solved in this paper using the constraint programming technique. The proposed system can deal with a heterogeneous constellation that consists of satellites with different maneuverability, placed in different orbits, and loaded with different payloads. The system's user can choose one of six optimization objectives, three of them were not used before, for constructing the satellites' mission plan. Searching within the system is performed using one of five different search algorithms. The system produces plans with different planning horizons ranging from one track to more than one month. The obtained results depict that the proposed system behaves, comparatively, in a perfect manner even when dealing with a complicated case study consisting of three satellites, 2,500 targets, and a one-month planning horizon.
Research Interests:
In this paper, we consider the problem of designing a MIMOFMRLC for multi-input multi-output (MIMO) systems that are highly nonlinear and possess a strong coupling effect between their states. It presents a challenging system to control.... more
In this paper, we consider the problem of designing a MIMOFMRLC for multi-input multi-output (MIMO) systems that are highly nonlinear and possess a strong coupling effect between their states. It presents a challenging system to control. The paper introduces analysis of the passive line of sight (LOS) stabilization system. The nonlinear dynamics of the system are first derived. An intelligent fuzzy controller is introduced. The fuzzy control presents a nonlinear control technique that compensates the system nonlinearity; hence, it is more appropriate to stabilize and control the system under consideration. The fuzzy controller is designed to decouple the relationship between the system state variables. The controller performance is verified through simulations and results. Such a controller possesses a learning mechanism that is able to form its rule-base by watching the system behavior. The learning mechanism utilizes a reference model that describes the desired performance. The de...