Abstract: Application of high-speed on-off valve in the hydraulic cylinder speed control system was researched in this paper. Series and parallel application schemes between high-speed on-off valve and hydraulic cylinder are proposed. Model of high-speed on-off valve and hydraulic circuit were established to carry out simulation. The speed and acceleration curve of hydraulic cylinder were achieved by the means of simulation with Simulink. The simulation curves show that, two application schemes can both control the speed of hydraulic cylinder effectively. Series application scheme can be only applied to small flow hydraulic system; parallel application scheme has wider application.
Abstract: This paper presents the digital PID controller design of magnetic levitation application. The highly nonlinear of electromagnetic suspension (EMS) system is hardly and limited the system control subjected to prescribed stability of system. Due to the nonlinear dynamics of system, the linearization of the nonlinear EMS plant is described by linear model. An attraction force about the prescribed nominal operating point of current and air gap positioning is chosen for linearization at a nominal operating point. Such a linear system, digital PID controller is designed for controlling the EMS plant. The system stability is validated by experiment methods. From the results, the reference of air gap position can be tracked with the desired nominal operating air gap position control as shown in practical manner.
Abstract: MEMS gyroscopes of frame structures are capable of isolating the quadrature error between the drive motion and the sense motion, which is often utilized in current gyroscope design. But quality factors of previous reported gyroscopes of frame structure are hardly over 1000, which are far more less than that of gyroscopes manufactured before with only one mass block for sensing and driving. Although the effectiveness of isolating quadrature errors is proved, the sensitivity is decreased as well as the power consumption is increased for higher drive voltage. Reasons why MEMS gyroscopes of frame structure has low quality factors is pointed out here with a method of anchor loss mechanism, and the energy dissipation is modeled with a 2 degree of vibration system, which tells the relationship between the mass ratio of the inner mass and the outer frame and the spring factor ratio for supporting masses, and the quality factor assess techniques is proposed here. Therefore the admissible parameters of the mass ratio and the spring factor ratio are given, which makes MEMS gyroscopes of frame structures have advantages of quadrature error isolation as well as high sensitivity. In the end, gyroscopes with optimized parameters and reported parameters are manufactured on SOI wafer, and variations of the quality factors as expected proves the rationality of the proposed energy dissipation model in this paper. For Process limitations, quality factors of gyroscopes of frame structures are improved lower than expected, but far more improved than previous reported gyroscopes, and better results should be realized in more mature and stabilized process.
Abstract: In this paper SVPWM （Space vector pulse width modulate）inverter model was built with the Matlab/Simulink based on the principle of SVPWM. Then based on that built the models of submersible motor’s control system which is supplied by SVPWM-inverter．Finally, ran the simulation and gave the results.
Abstract: The paper takes the lock ring synchronizer as the research object, and introduces its structure, working principle. Through theoretical derivation, obtaining the calculation formula of the synchronization time and analyzing further the influeccing factors. The research has great help for the future design.
Abstract: The optimal design for stackable piezoelectric power generation device and its micropower energy storage method is presented in this work. In this configuration, three different arrangement designs of piezoelectric power generation devices were put and compared for obtaining a greater produced output power. Evidence shows that the Sample 2 among the three different arrangement stackable piezoelectric power generation devices could avoid damage to the PZT-5H and achieve a highest instantaneous output power (5.175mW). Moreover, to establish the high efficiency energy storage system, using low power buck converter IC (LTC3588-1) was proposed. The obtained results show that a 15mAh Ni-MH battery could be fully-charged within two hours by utilizing the optimal arrangement design stackable piezoelectric power generation device combining with micropower energy storage system.
Abstract: In this paper, a framework for integrating a real-time digital simulator and EMS-OPF program is proposed and addressed, through two different communication architectures: asynchronous and synchronous. Validation of these communication architectures is carried out by Ethernet UDP/IP (asynchronous) and analog channels of IO card (synchronous). With this framework, both dynamic and steady-state performance of a power system can be studied easily in real-time mode.
Abstract: For today carrying out of observational measuring and processing of the gained effects without computer technology practically is not available. The importance of using automatic devices becomes more and more obvious. In many cases, when the matter is to work out the experimental devices and methods, there is a problem connected with control of experimental devices and with carrying out automatic measurement. For a solution of this problem experimenters often use different special electric devices which connect experimental devices with computer technologies. For example, such devices are analog-digital (ADC) and digital-analog (DAC) converter systems of electrical circuits etc.
Abstract: As a result of man’s intensive activities, the pollution of the world oceans and the pollutions of domestic waters reached such scales that the natural mechanisms of clearance are not capable of their utilisation. It causes the breakage of ecological balance, which becomes more and more difficult to control and causes natural excitation on the future of biosphere. Anthropogenic pollution includes various components, among which, nowadays, the first place belongs to oil and oil products. Fighting against this kind of pollution is a modern problem. By the literal data, the annual anthropogenic flow of oil products in the sea is caused by the loss of oil on tankers. It is known number of contact and non-contact methods of the pollution analyses of oil. Among them, the spectral optical methods are widely used, the major advantage of which is their expressiveness and distance. The laser methods should also be mentioned. Among them, the most sensible method is fluorimetry.
Abstract: To enhance the power of the engine and improve the emissions performance, The Intake air temperature signal , knock signal, throttle signal and power supply voltage signal were used as the correction references for the ignition advance angle. According to the parameter characteristics, the schemes of the measurement and control were proposed. The sensors were selected and corresponding parameters were determined. And then parameters of signal processing circuits designed, so that determined the moment of ignition. The experiment proved that the electronic ignition system designed in this paper, can meet the expected demand.