Applied Mechanics and Materials Vols. 300-301

Abstract: Definition of magneto hydrodynamic explosive munition is introduced. The technology that magneto hydrodynamic loaded EFP is presented. The magneto hydrodynamic power is generated by MFCG. The physical model of magneto hydrodynamic explosive munition using ferroelectric ceramics as primary source is established. The equivalent circuit of primary source, MFCG and magneto hydrodynamic accelerating model is analyzed by current transfer process. The security system is designed for the new ammunition, and its initiation timing is analyzed. A microsecond detonation control method is also given.

Abstract: According to the real structure and work condition of a high-flow gas pressure control valve used in recycling generating electricity project, a multidisciplinary design optimization (MDO) model is set up. Taking the structure and flow field analysis results as designing criterion, the MDO framework is put forward, which realizing the integration of multidisciplinary and two physical fields of control valve. To ensure that the gas transmission capacity which is the design prerequisite, the optimization takes reducing noise of control valve as system goal, while the valve wall thickness and flow velocity are decreased. And the Reynolds number, stress intensity and body total weight are also meet requirements. From the standpoint of fluid and structure, to realize MDO is of great practical significance for advancing research level of high-flow control valves.

Abstract: It is usually difficult to establish an accurate mathematical model for hydraulic servo system because of its complicated and non-linear properties. However, bond-graph method has its unique advantages in modeling such as processing multiple energy conversions. Furthermore, good results could be achieved by combining fuzzy control with normal PID control. As a result of air current load interfering with the system in changeable and complicated environment, process control is obviously important. Taking 1MW wind turbine pitch-control system as an example, a simulation research based on the above method is conducted.

Abstract: Abstract. PC-based open CNC system can fully take advantage of the computer's hardware and software resources, which can use a common high-level language: Visual C++ or Visual Basic to program. User can mix and use the standardized peripherals, application software flexibly, we use the self-developed five-axis CNC machine is experimental platform, which can develop open CNC system based on PC and motion control card. Using of five-axis machine motion control design based on "PC + motion control card" on Visual C++ platform.

Abstract: At present the spray cooling method is used to the high carbon chrome bearing steel in the forging process. The traditional manual method of spray cooling controlling easily cause the slow cooling speed and uneven. Especially above 850 degrees Celsius, it is possible to produce reticular carbide which affects the bearing service life. According to the shortage of the existing technology, the paper design a kind of bearing forging controlled cooling device which can accurately control the spray cooling mainly consisted of delivery area, spray area, soak area and measuring temperature area. This device can complete spray cooling, soaking, measuring temperature, and other functions, effectively solves bearing forging spray cooling accurate controlling problem.

Abstract: In this paper, we propose a wTouch interface for controlling a human-centered intelligent wheelchair. The wTouch interface is a touch panel which performs similar joystick manipulations while it provides convenient wheelchair control interface, as well as offers useful wheelchair status. In addition, reactive navigation techniques are also developed by combining with the obstacle information to perform collision free navigations. The obstacle detection sensor uses a laser range finder and the reactive navigation uses the artificial potential field approach. Finally, a wTouch wheelchair prototype is produced in our laboratory for evaluating the performance of reactive navigations.

Abstract: Electrically heated boiler is a large inertia, time invariant and nonlinear process. Classical PID control algorithm cannot make the system meet up the needs of performance index. Dynamic matrix control (DMC) predictive control algorithm is adopted to control electrically heated boiler temperature. Simulation result shows that the temperature control system’s overshoot is zero, settling time is 200s, the steady-state error is 9.7574e-006. Compared with PID control, DMC predictive control decreases the overshoot and settling time and improves the system dynamic performance. Aim at disturbance, improved DMC control algorithm is put forward and enhance the system disturbance suppression ability.

Abstract: With the development of the new kinds of permanent magnetic materials and the tech of drive circuits, more and more electromechanical actuators have been used in the space applications, such as tactical missiles, smart UAV and so on. This study presents an electromechanical actuator actuated by four Brushless DC motors (BLDC) driven rudder wings .Two different control schemes are implemented to regulate the output angle of the EMA rudder wings. Namely a fuzzy logic PID controller （Fuzzy-PID）and a genetic algorithm optimized PID (GA-PID) controller. The feasibility of the two controllers is evaluated both numerically and experimentally, it is shown that Fuzzy-PID leads to a loss of control in high frequency conditions, while, GA-PID can ensure the precise angle control and an accurate tracking performance.

Abstract: According to the requirement of smooth operation and accurate positioning for AC speed regulating system of mine hoist, a new control system that based on vector control of Fuzzy-PID was designed. The best control scheme for mine hoist was obtained, which was also validated by simulation comparison with conventional PID control system in the MATLAB/Simulink. The result showed that the proposal was feasible and had practical value.

Abstract: In general, the conventional sliding mode control design is assumed that the upper boundary of parameter variations and external disturbances is known, it causes high frequency chattering and high gain phenomenon by using sign function, else steady-state error by using sat function. Immune-Fuzzy theorem simplifies the complexity of humor system, as well as introducing fuzzy control. This paper presents an Immune-Fuzzy sliding mode controller (FISMC) not only eliminate the system uncertainty but also overcomes the drawback of sign function and sat function. Finally, the performance of the proposed method is verified by simulation. The proposed FISMC shows the robustness for the motor parameters variation and the improvement of chattering phenomenon.