Advanced Materials Research Vol. 1016

Abstract: A new hybrid model of control implementation is developed to realize trajectory-tracking controllers for quadrotor Unmanned Aerial Vehicles (UAV). This model is based on the Computational Fluid Dynamics (CFD) model and hybrid automata in order to accurately implement control parts of these vehicles, and can be applied to most standard quadrotor UAV platforms. The paper brings out step-by-step the controller development lifecycle for a quadrotor UAV, including the configuration and aerodynamic calculation model for the gathering preliminary inputs of the control application, the control analysis of dynamic model and general architecture, as well as the control design performed by specializing hybrid automata. The detailed design model is then converted into the implementation model by using open-source platforms in order to quickly simulate and realize the trajectory-tracking controller for this quadrotor UAV. Finally, this application was completely deployed and successfully taken on trial flights.

Abstract: Following the Model-Driven Architecture (MDA) approach, we have modeled and implemented a planar trajectory planning and tracking controller designed for Autonomous Underwater Vehicles or Autonomous Surface Vessels (AUVs/ASVs). Our approach covers steps such as the requirement, analysis, design and implementation to model and realize a controller for most standard AUV/ASV platforms. It also allows the designed elements to be customizable and re-usable in the development of new applications of AUV/ASV controllers. The paper describes step-by-step the development lifecycle of planar trajectory-tracking controller for AUVs/ASVs. Based on this approach, a horizontal trajectory-tracking controller of a miniature autonomous submerged vehicle is completely developed and successfully taken on trial trip.

Abstract: The numerical simulation method of active flow control technology was studied in this paper. The simplified mathematical model of the active flow control is established with unsteady velocity boundary condition at the specific location of model surface. The reliability of flow control model was verified by standard cases of CFDVAL2004, and the capability of capturing micro-jet flow characteristics for Spalart-Allmaras (SA) and Menter’s Shear Stress Transport (SST) turbulence model were analyzed. The results showed that the accuracy of SA turbulence model is better than the SST model, and flow control model meet the accuracy requirements for numerical simulation method.

Abstract: Investigation of symbolic representations of environments plays an important role for solution of various problems of robot visual navigation. In this paper, we study methods of symbolic trajectory description for mobile robot navigation. For this purpose, we use the fresco approach. We consider the problem of salient frescoes selection. In particular, we consider various modifications of the Levenshtein distance method. Also, we use different circular strings methods.

Abstract: A biped robot based its mobility imitating human movements; this development is focused on the movement of the lower limbs. The mobility of the robot is made by servomotors; because they work in a very similar way as the joints of the human’s lower limbs but with some restrictions. The logic of this system was coded on VHDL language to be implemented in a FPGA. The reason for using this hardware; is because it had fast reaction speed, its implementation is friendly and versatile also is able to handle multiple processes in parallel. This paper describes the servo characteristics and how it was used to through an FPGA make possible move a robot who imitates the human movements in the sagittal plane, also show the mechanical design. Shows that the FPGA is better suited in this case than a micro controller to follow multiple paths at the same time.

Abstract: Developing a robust control algorithm for an aircraft engine requires an accurate nonlinear mathematical model. In formation of a nonlinear mathematical model, some components like compressor and turbine are modeled by using component maps. These maps show the connection between the compressor performance parameters. To show this connection, map data is digitized by using some techniques. In this study, we digitized a compressor map data by using ANFIS (Adaptive Neuro Fuzzy Inference System). RMSE (Root Mean Square Error) were calculated for different types of FIS (Fuzzy Inference System) structures constructed with different number of membership functions. The model was formed by using all valid data which is collected from a small turboprop engine compressor. Results demonstrate that the designed ANFIS structure can serve as an alternative model to estimate both online and offline compressor performance parameters.

Abstract: Observation system is implementing an automatic visual for observation that has recently got a considerable interest to researchers. Nowadays, technology has reached a stage where mounting video camera is cheap and friendly-user tools causing a widespread usage of cameras in public or private areas. Finding available human resources to sit and watch the imagery is too expensive for most organizations to afford the cost of human operators. Moreover, observation process by operators is error prone due to fatigue, negligence and lack of ubiquitous surveillance. Therefore, it is important to develop an accurate and efficient automatic video analysis system for monitoring patient activity that will create good opportunities by saving the cost of human resource employment because vision system can perform observation process for 24 hours per day. The system will allow us to detect unusual events in the scene and warrant the attention of whomever in charge to take preventive actions. The purpose of visual observation is not to replace human eyes with camera, but to accomplish the entire observation task as automatic as possible

Abstract: This paper is focused on the application of Adaptive Nuerofuzzy Inference system (ANFIS) techniques in the model-based Fault Detection and Isolation (FDI). The objective of this study has been to create an online system for condition monitoring and diagnosis of specific faults for a Gas Turbine (GT) power plant. In order to study FDI and condition monitoring, accurate model of GT is needed. In this paper, the nonlinear Rowen's model is developed in Matlab/Simulink software to simulate the GT system behavior. Then, regarding the gain of artificial intelligence systems in FDI, the neurofuzzy inference system with capability of reliable learning and data approximating, is employed in developing the proposed FDI algorithm. In this paper, three types of faults have been considered, fault in the fuel flow rate, fault in the performance of turbine which affects the turbine exit gas temperature, and fault in the turbine which affects the turbine output torque. The results illustrate the effectiveness of the method in detecting and isolating the specified faults. Regarding the quality and the accuracy of the proposed algorithm, the method is introduced as the remarkable FDI methods of the stationary GT systems possibly extending to other similar applications.

Abstract: This paper addresses forward and inverse kinematics of a specific class of serial-parallel manipulators, known as 2(6-UPU) manipulators. This manipulator composed of two modules which consist of elementary manipulators with the parallel structure of Stewart Platform. At first, the Kinematics Model of the hybrid manipulator is obtained. As there is a highly nonlinear relations between joint variables, and position and orientation of the end effectors, the inverse kinematic problem of these manipulators is quite complicated to solve. In this study, wavelet based neural network (WNN) with its inherent learning ability, is used to solve the inverse kinematic problem. Also, proposed wavelet neural network is applied to approximate the paths of mid and upper plates in circle and spiral trajectories. Finally, the results of simulation show high accurate performance of proposed method.

Abstract: In this paper we present measurements and measurement methods carried out on construction and building materials in our Building Physics laboratory in University of Debrecen, Faculty of Engineering, Hungary. The investigations with different methods are so significant from the point of view of thermal sizing and designing of the buildings. The laboratory measurements of the thermal properties of materials and in-built structures are very important either for the manufacturers or the designers. In this communication the measurement result are presented. Thermal conductivities will be calculated after steady state thermal resistance measurements both from Calibration hot box (CC) and Heat Flux measurements carried out by Hukseflux (HF) apparatus. Calorific values of some insulating materials will be presented after combusting them in a CAL2K ECO type bomb calorimeter.