Applied Mechanics and Materials Vols. 220-223

Abstract: A mathematical model of engine throttle as the controlled object is established and then the neural network algorithms and PID control are combined. With the self -learning function of the neural network, self -tunings of PID parameters are realized. The method overcomes disadvantages of PID as parameters which are difficult to determine and embodies better intelligence and robustness of the neural network, the simulation is researched by Matlab and the results show that the PID neural network controller is more accurate and adaptive than conventional PID.

Abstract: Harvesting energy from the environment has been widely investigated to power and maintain low-power devices. This paper reviews the potential energy sources, piezoelectric conversion mechanism, recently proposed piezoelectric energy harvesters (PEH), and micropower management circuits. It can be concluded that the output power of PEH is still comparatively small, especially when the ambient excitation frequencies deviate from PEH’s resonant frequency. Future work should focus on tuning or widening the operate frequency of PEH so that it can match the ambient vibration frequency at all time. Moreover, flow energy harvesting techniques compatible with MEMS techniques demand in-depth study to facilitate the fabrication of micro PEHs.

Abstract: To ensure that the vehicular satellite receiver get enough of their own real-time, accurate attitude information, considering the requirements low-cost, MEMS (Micro- Electron Mechanical System) inertial device is applied to the design of attitude positioning system for satellite receiver. Because of the low accurate degree, inertial navigation can’t fully used to help receiver to produce parameter. This paper undertakes to make use of parameter of velocity and attitude produced by laser gyro navigation system that installed in the head of the vehicle as MEMS inertial positioning system external combination information resource. And to integrate the MEMS inertial positioning system in the model of combining velocity and attitude by using Sage-Hausa adaptive filtering algorithm to evaluate the error of inertial navigation system on line, and rectify its calculating result so as to improve its degree of accurate. Through numerous analogical grounds vehicle operation experiments, the MEMS attitude positioning could reach the degree of accurate requirements by satellite receiver, therefore the testing program is feasible.

Abstract: From the view of engineering, based on expatiating the features of systems biology, the paper discusses the workflows and the research emphasis of systems biology. It also explains how to model and analyze the dynamic process of signal transmitting network for a biological system by an example. Based on the complexity and uncertainty of the mathematical model, the right methods are chosen to realize the effective estimation of state variables and model parameters for the biochemical pathway.

Abstract: In order to improve the control accuracy and response speed of the intelligent vehicle steering system, a DC-motor controlled steering system using an IPC (Industrial personal computer) is designed. The hardware of the system is developed by analyzing the dynamic steering model. A new control method of Fuzzy-PID controller with RSDA (Rough Set Data Analysis) is proposed. Experimental results using the proposed control strategy show better performance and robust properties than the ordinary Fuzzy-PID.

Abstract: Adaptive projectile is intelligent ammunition that adopts optical, mechanical, electrical, material and other high-tech and takes simple guidance or adaptive way of trajectory. It can sensitively recognize the target and automatically attack the target. Aiming at the requirements of the adaptive projectile, a novel piezoelectric actuator is designed in this paper. Through certain technology, ceramic rod is made by piling up and sintering piezoelectric ceramic chip, and four ceramic rods are evenly fixed along the circumference on the backplane of the actuator, then the four ceramic rods are applied with different size, positive and negative voltage, the linear displacement is coupled by spherical linkage and angular displacement can be output at the predetermined position of the cross circumference. Based on the design, the mechanical model and piezoelectric heap coupling mathematical model of actuator are made. After calculating, piezoelectric ceramic heap of type PST150/14/120VS20 should be used. In theory, under the condition of static state and no-load, a maximum angular displacement output of 4.5 degrees can be achieved. After numerical simulation, when the head angle is 4.5 degrees, the range extending rate of the adaptive shell can reach 80%.

Abstract: This paper presents a Fuzzy Logic Control Strategy (FLCS) for an Extended-range Electric Vehicle (E-REV) with series structure. The control strategy design objective of the E-REV is fuel economy. Based on the State of Charge (SOC) of the battery and the desired power for driving, the power required by the vehicle is split between the engine/generator set and the battery by the FLCS. The engine can be operated consistently in a very high efficiency area and the SOC of the battery can be maintained at a reasonable level. Some standard driving cycles and two control strategies of Power Follower Control Strategy (PFCS) and FLCS were simulated with AVL-Cruise and Matlab/Simulink to analyze the vehicle performance. Some simulation results are compared and discussed: the FLCS indicates better performance in terms of fuel consumption.

Abstract: In order to achieve an effective control approach for hypersonic vehicle over a wide flight envelope with uncertainties of structural dynamics and system parameters, a unified modeling and improved switching controller design approach is proposed, and the Adams Customized Development Platform of Flight (ACDPF) has been developed to implement it. The paper firstly discusses the main issues related to the model of the ACDPF, which can be set parameters by several blocks. And it also supports the reuse of modeling among similar missions, thus cutting down the design effort for new model. Then, the improved switching control with baseline controllers and robust adaptive controllers are selected in order to adjust control law to compensate for uncertainty. Finally, the effectiveness of the proposed approach is demonstrated by illustrative case studies and simulation results show that the approach provides a well tracking performance.

Abstract: This paper describes a precision control method for a magnetic drive actuator used for the laser cutting to realize high speed and high accuracy machining. Firstly, a zero bias current method is applied to drive the electromagnets to achieve a high-precision and long-stroke of the actuator. Secondly, a compensation method of the zero point of the displacement sensors is presented to prevent the generation of the disturbance force produced by the elastic hinges. Finally, the positioning performance of the actuator is evaluated through experiments and the experimental results show that the actuator has a positioning resolution of the order of micrometer, a bandwidth greater than 130Hz, and a positioning stroke of 1mm.

Abstract: Smart materials are a group of solid-state materials whose geometric shape can be related to an energy input in the form of heat, light, electric field, or magnetic field. In the application of active materials to electromechanical energy conversion, electrical energy may be input to the material and the resulting deformation of the material can be used to move a load. The most common smart materials are piezoelectrics, magnetostrictive, and SMAs. In this paper, a microgripper is designed based right angle flexure hinge and driven through piezoelectric ceramic stack. The calculation formulas of amplifying ratio and natural frequency of the microgripper structure were derived. From the analysis, the maximum stress is 147Mpa that under the allowable stress of 65Mn. It can work in a stable status.The results indicate that, the microgripper all are satisfy the need of design .