Proportional-Integral-Derivative (PID) controllers have been regarded as one of the most prevalent and successful techniques for controlling dynamic systems. However, in the presence of uncertainties and complicated systems, their operation may be undesirable. The major purpose of this research is to assess and improve the performance of the PID controller in the variable load crop spraying quadcopter navigation system using fuzzy-based approaches. At first, the PID controller parameters are fixed and then are tuned based on a look-up table according to the quadcopter load changes. The simulations reveal that the PID controller with fixed parameters or based on the lookup table does not have its expected performance, in the presence of uncertainties such as load variations, and hence it is required to tune the parameters more correctly. Therefore, here the fuzzy systems are utilized for online parameter tuning of the PID controller in the parameters in the variable load spraying quadcopter navigation system. The proposed fuzzy-based PID controller achieves higher accuracy and more stable navigation compared with the fixed-parameter PID controller or look-up table.

In this paper, a new method for flocking quadcopters is introduced. For this purpose, the idea of two-level control has been used, where the high-level controller is the same as the flocking algorithm and acts as the path designer of quadcopters. Moreover, tracking of the generated desired path is performed by a low-level controller. The main focus of this paper is on the high-level controller. A novel leaderless flocking algorithm is introduced, where new potential functions are generated using fuzzy logic to achieve a proper lattice. The introduced potential functions have a minimum value in the lattice positions. Therefore, the control signal minimizes its value by using the gradient-descent method to reach the desired situation. A safety radius is defined for every agent such that using the proposed flocking algorithm, the quadcopters do not enter each other's safety region. The stability and convergence of the structural and transitional dynamics of the system are shown. Finally, the proposed method is evaluated through simulations of five quadcopters. The results show that The proposed method provides better performance in creating a lattice, and maintaining obstacle as compared with recently published methods in literature.

Electrooculogram is a bio-potential signal that can play an important role in Brain Computer Interface systems. EOG, which is the result of moving human eye bulb, has the advantage of relatively easy recording due to its higher amplitude and signal-to-noise ratio compared to other modalities (e. g. EEG). Real-time processing, classification, and feature extraction are another important factors in applicable BCI systems. In the present study, a real-time processing and cost effective BCI system have been designed and developed based on EOG signals. It contains an updated eyeglass for fixing EOG electrodes on the subject’ s face and a 3D accelerometer for detecting subject’ s movement. EOG signals were acquired by subject’ s eye movement toward the four middle part of screen edges, which was placed in front of him/her. Expected results of the system was real-time generating of four different digital commands (quadcopter navigation) based on the eye movement of a subject in four different directions (up, down, left and right). At the end system have been tested on five different Subjects (five trials for each subject), and 94. 4% of system accuracy in detecting eye movements have been achieved.

Progressive collapse studies generally assess the performance of the structure under gravity and blast loads, while earthquakes may also lead to the progressive collapse of a damaged structure. In this study, the progressive collapse response of concentrically braced dual systems with steel moment-resisting frames was assessed under seismic loads through pushover analysis using triangular and uniform lateral load patterns. Two different bracing types (X and inverted V braces) were considered, and their performances were compared under different lateral load patterns using the Nonlinear static alternate path method recommended in the Unified Facilities Criteria (UFC) guideline. Eventually, the seismic progressive collapse resistance of models was compared to their progressive collapse response under gravity loads. These studies showed that models under the seismic progressive collapse loads satisfied UFC acceptance criteria and limited rehabilitation objective. The structures had better performance under seismic progressive collapse than models under gravity loads because of more resistance, ductility, suitable load redistribution, and more structural elements that participated in load redistribution. Furthermore, despite studies on progressive collapse under gravity loads, the dual system with X braces showed better progressive collapse performance (more resistance, residual reserve strength ratio and ductility) under seismic loads than the model with inverted V braces.

One of the systems that be used in order to prove efficiency of control methods with its easy structure, is inverted pendulum system. The object of controlling this system is equilibrium of pendulum with limited states. For this purpose, different methods are used. One of the best methods is fuzzy controller with defuzzy supervisory controller. In almost methods, limitation of initial conditions is important problem. In this paper for solving this problem, a new method is proposed. Because of similarity to back stepping method but its more applications than last method, we named this method to Generalized Back stepping Method.

Staggered truss system is one of the types of lateral bracing systems in steel structures. In this system, lateral forces are transmitted through the rigid floor diaphragm between adjacent trusses. The columns of the staggered truss system are placed only in the outer walls and the middle columns are removed. Hence, a large open space without columns is achievable, which is architecturally appropriate. In this paper, the effect of geometric characteristics of staggered truss systems such as the ratio of the opening length, the type and arrangement of the side trusses in seismic performance is investigated using ETABS software. For this purpose, the ability of the analytical model was first validated to estimate the available experimental results. It was observed that the analytical result is in good agreement with the results of the Experimental model. Then, by examining several different models, the effect of the length of the middle opening was investigated on the seismic parameters of the Staggered truss system. The results showed that the ratio of the length of the middle opening is very important in seismic performance; So that this ratio can have a direct effect on the ductility and stiffness of the structure. Finally, the effect of truss type used in side openings was evaluated on the best span ratio based on the best level of seismic performance. In this paper, three types of structures are used: short, medium and high.

By applying finite difference formula to time discretization and the cubic B-splines for spatial variable, a numerical method for solving the inverse system of Burgers equations is presented. Also, the convergence analysis and stability for this problem are investigated and the order of convergence is obtained. By using two test problems, the accuracy of presented method is verified. Additionally, obtained numerical results of the cubic B-spline method are compared to trigonometric cubic B-spline method, exponential cubic Bspline method and radial basis function method. Implementation simplicity and less computational cost are the main advantages of proposed scheme compared to previous proposals.