Advanced Materials Research Vols. 989-994

Abstract: In view of characteristics owned by high and low gimbals, for instance pure lag, large inertia, strongly nonlinear and so on, which was employed in low light level (LLL) weapon sight reliability detection system. The basic working principle and mathematical model of Dahlin and Smith predictive control algorithm were mainly researched. And ideal control curves were obtained by software emulation. The simulated results showed that the two algorithms each have their advantages, shortcomings and the proper situations, but as to improve the control efficiency of system, the Dahlin is superior.

Abstract: According to the method described in Technical Manual of Aircraft Noise Evaluation Procedures, this system can predict the EPNL (Effective Perceived Noise Level) of aircraft take-off, approaching and side boundary. The system also contains the function of managing andcalling NPD database, and can assess the predictive value basing on the noise stringency curve. This saves a number of cost for the airworthiness certification of aircraft noise, and is a new engineering practice which has a good application value.

Abstract: It is the premise conditions of dynamic balance monitoring and control technology that the unbalance vibration signal is separated accurately. Based on the theory analysis of EMD (Empirical Mode Decomposition), the time field method of unbalance vibration signal separation is proposed. The basic principle is that the reference signal and radial vibration of rotor must be simultaneously measured, and then the IMF(Intrinsic Mode Function) components are separated based on the EMD method. The time field signal of unbalance vibration can be identified by comparing the IMF’s frequency with rotational frequency. The method effectiveness has been proved by experimental data analysis.

Abstract: The rapid prototyping technology was introduced, including its definition, principle and characteristics. The advantages of rapid prototyping technology in new product development were analyzed. Application of rapid prototyping technology in design of mechanical parts, industrial model, medical model, ceramic products, automobile model and products based on ergonomics was discussed. The feasibility of rapid prototyping technology in product design and the optimization direction was prospected.

Abstract: The effectiveness evaluation problem of electronic warfare command and control system (EWCCS) under complex electromagnetic environment is investigated by using the analytic hierarchy process (AHP) method. First, the evaluation hierarchy structures of EWCCS under complex electromagnetic environment are put forward and can be classified into target hierarchy, rule hierarchy and scheme hierarchy. Then, the AHP Algorithm is given as a preliminary knowledge to evaluate the effectiveness evaluation of EWCCS under complex electromagnetic environment. Finally, an effectiveness evaluation example of EWCCS under complex electromagnetic environment is considered by using AHP Algorithm.

Abstract: A problem of quadrotor’s control system based on DSP is investigated in this paper. STMS320F28335 is used as the main processer, due to its advantages of high-speed processing capability and powerful floating point processing capability. The inertial measurement unit is selected for inner-loop attitude control, while the optical flow sensor is adopted for outer-loop attitude compensation. Infrared range finder is choosed for altitude control with PID method. Quadrotor uses XBee-Pro wireless module to contact with ground station and sends statement information in accordance with the Mavlink protocol. Test results show that the control system is reliable and can meet the requirement of the attitude control system.

Abstract: One rolling bearing fault diagnosis method based on minimum entropy deconvolution (MED) and morphological filtering is proposed. Firstly, the strong background noise of rolling bearings is decreased by the MED method, then the morphological filtering which have different length of structure elements is designed and applied to the de-noised signal. Subsequently, bearing’s fault characteristic frequency is extracted by the amplitude spectrum analysis to the best morphological filtering component which have the maximum kurtosis. This method is used to analyze both a simulated bearing signal and an experimental inner ring fault signal, and the good result validated the effectiveness of this method.

Abstract: Prediction of disk spring failure life due to stress relaxation is necessary for users; the problem was not solved before. According to special test requirement, we modified a 100N mechanical testing machine into high temperature testing equipment which can be used for different types of disk spring. With a test for 36 days on a group of 45×22.5×3.5×2.5 mm disk springs, a result of prediction of 3.38% load loss ratio after 12 years relaxation is obtained, these disk springs are qualified. Our modified equipment has the advantages of real time, heavy loading, high sensitivity and good generality.

Abstract: Brick cutting machine is the important device during the process of making bricks. The automatic control system, device of power and the pattern of cutting machine have been developing well. The new ideas, new technology and achievement of the brick cutting machine are taken out. The important achievement and application of the cutting machines are introduced, as well as the development tendency.

Abstract: This paper designs a single-phase inverter.Battery as a 12V DC input, and output for the 24V,50 HZ standard AC wave. The load is resistive.The power supply adopts the Boost booster and two full-bridge inverter transform. For the control circuit, the preceding Boost converter using tl494 chip control closed-loop feedback and for the inverter part, adopting the 6N137 to finish the optical coupling isolation.Then,through the DSP (TMS320F2812) to complete the output of SPWM modulation.And the modulated SPWM signal can drive chip IR211 conducting the full bridge inverter. Finally, through a low-pass filter output the standard sine AC inverter power.