Papers by Keyword: Pressure Control

Abstract: A pneumatic microvalve which can be used in pneumatic pressure control for lab-on-a-chip applications is presented in this paper. In order to realize a feedback control and miniaturization, a micro stepper-motor is selected to control the opening of the microvalve. After introducing the structure and working principle of the pneumatic microvalve driven by a stepper-motor, the static flow rate simulation of pneumatic stepper-motor microvalve is processed in the condition of different opening sizes of the microvalve and pressure difference over the valve. The stepper-motor microvalve is fabricated and corresponding control circuit is designed. Experiments on static and dynamic characteristics of the microvalve are carried out. Good agreement has been shown between the simulation and experimental results.

Abstract: The paper presents the general structure and the feedback control method of a compact type of driving simulator, having a mobile suspended seat actuated by pneumatic muscles. The completed simulator is intended to be used as an advertising demonstrator for the university and also for various research projects. In order to better observe the viability and behavior of the proposed feedback structure, a scaled model is constructed using similar pneumatic muscle actuation of a 3+1 DOF suspended mass. For analysis purposes, multi-step pressure and tri-state muscle contraction control is employed. The feedback data is exchanged between the software simulator and the motion control PLC by using a custom software application.

Abstract: In the present paper is presented a numerical simulation of an electro-hydro-mechanical system of adaptive transmission of mechanical power. This system is based on a hydraulic circuit consists of a hydraulic pump with constant flow and a hydraulic motor with variable flow ordered so that the pressure in the circuit to remain constant. For a variation of the ramp and step signal sources of loads, are presented the main features of operation of adaptive transmission. Analysis of dynamic stability of mechanical transmission is made through the linear analysis with Bode diagrams. Simulation of transmission operation is performed with AMESim.

Abstract: When trains with high speed pass through the tunnel, there is pressure fluctuation in the tunnel which will cause discomfort of the driver and the passengers. Using unsteady one dimensional flow model, the aerodynamic effect caused by the train with speed of 120km/s running through the tunnel was calculated and analyzed. The results show that the routine tunnel size of Ф5.5m for metro lines can not meet the standard for comfort level. Instead, tunnels with inner diameters of 6.8m and 10.36m were recommended.

Abstract: Algorithm and structure of automatic pressure control in main oil pipeline are proposed in the article. Model of a process is being researched. Obtained results are being described terms energy losses minimization during pressure control. Crucial feature of an algorithm is an application of additional bypass valve.

Abstract: A gas pressure regulation system with a control valve is introduced. The selection method, considering the effect of the valve opening and the movement of the valve spool upon the valve control performances of the gas pressure, is discussed, and the effect of pressure control with the selected control valve is presented. The results show that the control valve that is selected using the proposed method has good control characteristics of the gas pressure.

Abstract: By analyzing pressure control process of some wind tunnel spraying water supply system, a simplified method is presented, which can avoid interference between different pressure control circuits. Regulating valve is the key control equipment, and its regulating formula is given after detailed calculations and analysis. The simulation of pressure control for spraying water supply system is researched based on AMESim, which provides the theoretical support for experiment. In the end,experimental results show that the control method is effective, and water pressure precision can meet the technical requirements.

Abstract: Pressure type pneumatic measuring is the most wildly used method in overlap value testing, which depends strongly on the constant pressure of gas supplying. However,control of pressureisrarely done before.This paper presentsa design of a new overlap value measuring system with pressure control sub-system, mechanical platformand a program-controlled sub-system. A hybrid controller is developed combined with fuzzyself-adjusting PID and time-optimal control. The final version of this controller is a computationally efficient analytic scheme suitable for implementation in thereal-time closed-loop pressure digitalcontrol. At last, the system control software developed on LabVIEW is briefly introduced.

Abstract: Owing to nonlinearity, time-delay and complexity of pressure control system in vacuum casting (VC) process, the traditional pressure tuning method can’t guarantee the good performance and thus high quality product nowadays. In this paper, a novel pressure control strategy for vacuum casting process, combining fuzzy PID and neural network methods, is proposed to solve this problem. The proposed strategy can on-line regulate pressure difference between low and upper chambers of VCM to meet the pressure requirement in VC process, thus ensuring high quality part. With the aid of Matlab and configuration software – Forcecontrol, the proposed fuzzy self-tuning controller is implemented in a sample machine. The experiment result shows that the presented pressure controller can track the pressure profile accurately and thus can further improve the product quality.

Abstract: With the development of the advanced precision-guided missile and anti-missile system, high precision, high penetration ability and Low energy consumption have become an important direction for the missile. A new missile electro-hydraulic actuation system with dual independent closed-loop is put forward with the trend of high performance and energy-saving, and then the operating principle and process are discussed. Finally the accurate mathematical model is established, and the influence of the different basic pressure on the dynamic performance is analyzed. The simulation results show that the new proposed scheme has made great improvements in reducing the zero-control current of the system, but the efficiency and performance of the actuation system should be considered integrated due to the decrease of the dynamic performance, so it is practical for the future development of the missile electro-hydraulic actuation system.