Papers by Author: Yong Wang

Abstract: A vibro-impact dynamic model of a typical single-stage spur gear train has been proposed in this study. The lumped parameter dynamic model includes the constant meshing stiffnesses, the linear time-invariant viscous damping values and the gear clearance (backlash) non-linearity allowing teeth separations. With taking account of the effect on impact of gear tooth when meshing, the dynamic equations of motion are solved for the steady period response by use of analytical method under given periodic motion conditions. The feasibility of the given periodic motion conditions is demonstrated by comparing the analytical results with that of numeric simulation method. A Poincaré map of the system is established. The stability and bifurcation of the system are studied using analytical methods. Finally, the theoretical analyses are verified using numerical simulation.

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: Hydrostatic transmission with secondary regulation can regenerate inertial and gravitational energy of load. Based on deeply analyzing the working principles and energy-saving theory of the secondary regulating transmission system under variable pressure rail, regenerating the transmission system’s inertial energy by controlling rotation speed was put forward. Considering large changes of the parameters of the transmission system and its non-linearity, a fuzzy-neural network control was adopted, and the mathematical model of the system was established, then the simulations of the performance of the transmission system has been conducted. The conclusion was made that the inertial energy can be reclaimed and reused,and the self-adaptive ability and controlling performance of the secondary hydraulic transmission system is improved.

Abstract: The flow coupled secondary hydraulic lifting system of the excavator bucket was presented, also its structure, working principle, and performances. The math model of the lifting system is established, using the math mode to control the hydraulic accumulator, and then realize process controlling of the energy recycling and reusing. Further, the system pressure range was expanded, the energy reusing effect and efficiency were improved.

Abstract: A secondary hydraulic transmission control method is presented based on the fuzzy-neural network control which introduces the fuzzy control into neural network. The simulation results show the self-adaptive ability and controlling performance of the secondary hydraulic transmission system is improved.

Abstract: Direct drive electro-hydraulic actuator is a new type of hydraulic transmission with easy maintenance and high efficiency, which has been widely used in municipal engineering (such as water pipe network, gas pipe network), nuclear power plants, and other occasions. For these applications, we designed the electro-hydraulic valve actuator based on Internet of things technology (IOT for short). This paper introduces the mechanical structure and the working principle of the direct-drive electro-hydraulic valve actuator, analyzes IOT architecture. Detailed design was carried on according to the IOT architecture and related experiments have been done. The actuator can automatically, accurately control valve opening, be monitored by PC remotely, display device real-time information through LCD and be operated by touch screen.

Abstract: Direct drive volume control (DDVC) electro-hydraulic servo system has many advantages compared to the valve control system. However, its application scopes were restricted by its poor dynamic performance. To study the reason for the low dynamic response, mechanical model of DDVC electro-hydraulic servo system is established. Structure parameters influencing the dynamic performance are analyzed. To optimize the structure parameters, the methodology of orthogonal experiment is presented. The selection of factors and levels of the experiment and the choice of the evaluation index are also revealed. The proposed methodology is carried out by simulation software and an optimal configuration is obtained. The dynamic response of the DDVC system with the optimal parameters is simulated. The results show that the dynamic performances are improved. The cross-over frequencyincreases from 0.0046 rad/s to 0.0442 rad/s, and the rise time T_r decreases from 488.6s to 47.90s.

Abstract: Control valve is a kind of essential terminal control component controlling the parameters of fluid such as flow and pressure in process-control. However it is a complex nonlinear, multi-input and single-output (MISO) system that is hard to model by traditional methodologies. To establish the pressure model of control valve, this paper presents a Hammerstein modeling method based on the least squares support vector machines (LS-SVM). The linear model parameters and the static nonlinearity of Hammerstein model can be obtained simultaneously by solving a set of linear equations followed by the singular value decomposition (SVD). As an example, a set of actual production data from a controlling system of chlorine in the salt chemistry industry were applied. The simulation results demonstrate that the obtained LS-SVM Hammerstein model can efficiently approximate the pressure of a control valve. Furthermore, the proposed LS-SVM Hammerstein model can be used in artificial intelligent control and the default diagnosis.

Abstract: Apply the CFD numerical simulation the internal flow field and noise when the control valve is bonnet leakage and trouble-free. Research shows that bonnet leaking has almost no effect on valve inlet and outlet flow field. It is an impact on valve body flow field and the greatest impact on balance cavity. It changes the flow direction of the balance cavity and produces right vortex, in balance cavity where originally without noise, the tremendous noise appeares and improves the noise of the surrounding area.

Abstract: Establish valve stem leakage flow channel model, apply the CFD numerical simulation the internal flow field and noise. Research shows that it is no effect on the valve inlet and outlet flow field when the valve stem leakage. It is no effect on the valve body flow field and the greatest influence the balance cavity flow field. Changing the flow direction of the balance cavity and produce left vortex, it break left vortex of right part. New tremendous noise sources appear the balance cavity and improve the noise of surrounding areas.