Applied Mechanics and Materials Vols. 373-375

Abstract: With the application of inverter in high-voltage motor, the traditional current differential protection cant be used because of the variable frequency. So it adopts low sensitive current instantaneous protection as main protection, which doesnt meet the security standard of grid state. In order to improve the sensitivity and reliability of high-voltage motor protection, a new method based on current sampled values is proposed in this paper, which adapts to the variable frequency system. After a brief description about the impact of inverter on main protection of motors, it introduces the principle of sampled value current differential protection and variable RS sampled value algorithm. A matlab example is used to simulate. On the whole, the simulation and analysis of the calculation results verify the feasibility and reasonableness of the method. Therefore, it provides a new approach for the protection of high-voltage motor in variable frequency system.

Abstract: Four-rotor micro aerial robots, also called Quadrotor UAVs, have received much attention not only in academic research world but in military as well as commercial applications. In this paper, the quadrotor model is built and its dynamics character is analyzed by making a comparison with the missiles one. Furthermore, various modern strategies used for quadrotor control are presented.

Abstract: Monitors are added upon problematic siphons to avoid deadlocks. Li and Zhou add monitors to elementary siphons only while controlling the rest dependent siphons to save cost. After failing a Marking Linear Inequality (MLI) test, they perform a Linear Integer Programming (LIP) test (NP-hard). We proposed a new MLI test earlier to avoid the LIP and extended it to S3PGR2 (systems of simple sequential processes with general resource requirements) for strongly dependent siphons (SDS). The control policy for weakly dependent siphons (WDS) is rather conservative due to some negative terms in the MLI. This paper shows that WDS and SDS have the same controllability (i.e., MLI). As a result, the control for WDS needs no longer be that conservative. We also develop an optimization (by redundancy elimination) of the computation required for LIP test to ensure deadlock prevention of S3PR (Systems of Simple Sequential Processes with Resources). A favorable result for this policy is that any n-dependent (n>2) WDS (similar to SDS) needs no monitor and hence the complexity for synthesizing a controller becomes polynomial.

Abstract: Integrated design about guidance and control of homing unmanned aerial vehicle (UAV) is proposed. Firstly, an integrated guidance and control model with uncertainties can be described. Secondly, a nonlinear observer is designed for the integrated guidance and control model. Finally, the simulation results show that the nonlinear adaptive guidance law using the proposed integrated design model can perform better than the one designed separately.

Abstract: This paper proposes a robust adaptive neural network controller (RANNC) for electrode regulator system. An equivalent model in affine-like is derived for electrode regulator system. Then, the nonlinear control law is derived directly based on the affine-like equivalent model identified with neural networks, which avoids complex control development and intensive computation. Pretraining is not required and the weights of the neural networks used in adaptive control are directly updated online based on the input-output measurement. The proposed nonlinear controller is verified by computer simulations.

Abstract: The past decade witnessed a growing concern about the increasing energy consumption of central air-conditioning. Traditional PID control is practicable in partly cutting energy costs but not in achieving their energy-saving potential fully for those central air-conditioning, especially in great nonlinearity condition. To achieve this, the fussy-PID control and management-matrix strategy are introduced in this paper, with their advantages such as: better dynamic responsibility, better adaptability, better robust control, mathematic model invariant and heating/cooling on-demand allocation. Based on this theoretical assumption, an experiment is designed and implemented in a university library. Consequently, the experiment proves that the combined control system, with fussy-PID control and management-matrix strategy, is stable, fast, and feasible in energy-saving of central air-conditioning by targeting at its water system control.

Abstract: The strip thickness control of 1500 for hot rolling with the MATLAB simulation not only improve the accuracy [, the dynamic and steady state performance of the system [2], but also enhance the robustness of the system by the establishment of expert fuzzy controller. The expert fuzzy control in hot strip thickness control provides a new and available application example in this paper.

Abstract: Extended state observer (ESO) based output-feedback control strategy is proposed for the attitude control of a quadrotor aerial vehicle in this paper. By using ESO technique, the generalized disturbances are estimated from output signals. According to the sliding mode method, the attitude controller with disturbance compensations is proposed for the attitude tracking control of a quadrotor vehicle. The theoretical analysis reveals that all signals in the closed-loop system are ultimately uniformly bounded. The simulation results validate the efficiency of the proposed method.

Abstract: An adaptive dynamic sliding mode pitch control strategy for the output power control of wind generation systems in above rated wind speed range is presented in this paper. The corresponding controller is designed, which consists of an adaptive dynamic sliding mode controller, virtual damping controller. These variable pitch control systems have several advantages over the traditional wind turbines, such as reduction of the mechanical stress, improve quality of electric energy and mitigate tower fore-aft vibration and gearbox vibration. Traditionally, wind turbine pitch control system using mainly proportional integral (PI) controller. However, such kind of controller does not adequately handle some inaccuracies mainly leading to non-optimal power factor. These may decrease wind turbine performances. Therefore, using robust control and additional sensors to help the controller to achieve its objects more effectively, such as adaptive sliding mode control, damping controller will allow to tuning the wind turbine rated power to improve power quality. Finally, simulation results are demonstrated to validate the proposed controllers.

Abstract: Several control methods are discussed in this paper and the function of feedback of control is analyzed. The most important function of feedback is supervision, thus, make full use of the feedback information is a good way to study control problems. By using the characteristics of open-loop and closed-loop control and the effects of feedback, the authors design a controller structure and provide a feasible multi-mode intelligent control algorithm, moreover, the excellent performance of the algorithm is verified by simulation.