Papers by Author: Yu Wan Cen

Abstract: The distributing flow system with slide valves is generally used for nitrogen-inflating hydraulic beaker, but it has some main bad problems. To solve these problems, a new distributing flow system was designed by applying the technology of screw-in cartridge. Then, the system mathematical model for the hydraulic breaker was proposed, and the performance of hydraulic breaker was analyzed by simulation. The simulation results show the principle of the distributing flow system designed is correct and feasible, moreover established mathematical model is accurate and reliable. It provides a viable technical approach and theoretical reference for the development of high-performance hydraulic breaker.

Abstract: To improve the regulating characteristics of impact energy, simplify structure of hydraulic hammer, a new pulse modulation hydraulic hammer is presented in the paper which can help regulate its impact frequency easily. The motion equations of the hydraulic hammer are established, its simulation model is obtained and the dynamic simulation is carried out on AMESim. The dynamics of high-speed ON/OFF valve is taken into account in the simulation model. The tendency of simulation results conforms to experimental results; it shows that the pulse modulation hydraulic hammer is feasible, and the hydraulic hammer model is reasonable. The time delay in high working frequency is also analyzed.

Abstract: For the demand of AGV’s environment modeling and path-planning,the paper discusses how to establish static environment model of visibility graph and proposes a visibility table method.Moreover,based on the environment modeling,we put forward a new kind of global path-planning algorithm by the combination between ant colony algorithm and immune regulation.

Abstract: The steel strip processing systems rely on accurate lateral positioning to achieve high processing speeds and improved product quality. In real steel strip process systems are not just nonlinear and time-varying but also highly uncertain. This research focuses on the disturbance estimation approach to modeling unknown dynamics of physical plant. The Euler’s beam theory with boundary condition is considered to derive the equation of the moving steel strip. To consider unknown dynamics in the real steel strip, a nonlinear state space equation is employed to describe unknown dynamics of the moving steel strip. The nonlinear part of this system is proposed as an unknown disturbance input to this system. The neural-based observer (NNO) is designed to estimate nonlinear unknown dynamics. The online weight-updating mechanism is a modified version of the backpropagation algorithm with a simple structure together with an error-modification term added to guarantee the robustness of the observer. The measure of sensor and estimation of observer pair of input and output is used to train the weight of NN. The simulation and measure result shown that the NNO can track the un-modeling dynamic of nonlinear systems.

Abstract: As electro-hydraulic control system of strip steel CPC has some special characteristics, such as strong nonlinear, changes in structural parameters, serious time-delay and the very difficultly of establishing accurate mathematical model, the integral-separate PID improved predictive control algorithm was proposed on the basis of the new mathematical model. Firstly, the integral-separate PID algorithm was used to make system asymptotic stability and reduce overshoot of system. Secondly, the predictive control algorithm was proposed, error feedback correction model was improved, and predictive control signal was optimized with rolling method. Finally, the system was simulated and analyzed in noise and pulse disturbance. The simulation results show that this algorithm can effectively improved abilities of anti-noise and anti-load disturbance, increases robustness and tracking capability of strip steel CPC system; furthermore, it can improved speed of system response and decrease time-delay and overshoot of system. Therefore, this algorithm can well meet the need of electro-hydraulic control system for strip steel CPC system.