Applied Mechanics and Materials Vols. 644-650

Abstract: Control of pulp pH value is the key step in the process of washing zinc oxide. Due to the characteristics of large time delay and strong nonlinear, the control of pulp pH value is very difficult. In this paper, aiming at the above problem and according to the features of washing operation of zinc oxide powder, design a control system of a fuzzy controller, secondary fuzzy controller and PI controller.

Abstract: During the rice mill structural design process, static analysis is an extremely important field, not only decide to what the structure size is, but also for the subsequent fatigue analysis, providing the basis for the overall stability analysis. In this paper, vertical screw conveyor vertical rice mill, rice discrete element analysis simulation under different speed, the internal movement of materials to simulate the process for improving the productivity of the vertical screw conveyor has a certain significance. Providing an important basis for further design optimization of the rice mill structure.

Abstract: In this paper, the monitoring and management system of bridge crane is developed. The various parameters in the system can be set via client computer, without facing the noisy environment to manage the equipment on site. Through a simple and efficient combination of hardware and software resources, working environment for the staff is improved and downsizing for efficiency is realized. At the same time, executives can keep abreast of the field operation and real-time data, and the system can strengthen the function of the communication between the machine equipment. Practice proves that the system is a kind of convenient, quick, safe and effective management method.

Abstract: Because of the reliability requirement for the motor driving system in practical application, and based on analysis of the working principle of a fault-tolerant inverter, the direct torque control (DTC) for brushless direct current motor (BLDCM) fed by four-switch three-phases inverter (FSTPI) when the inverter faults is widely studied. According to the characteristics of (BLDCM), the voltage space vector for BLDCM-DTC fed by FSTPI is redefined due to the dissymmetric voltage space vector of TPFSI. To reduce the number of power device switching, the implementation method of four-switch SVPWM with seven-segment scheme was presented. Therefore, the system model is established as a result of the detailed analysis of voltage space vector and the control principle of the BLDCM-DTC without flux linkage observation fed by FSTPI. The validity and effectiveness of the proposed scheme have been verified through the simulation and experimental results.

Abstract: To find the optimal path of mobile robots,a novel robot path planning strategy based on hierarchical control fuzzy algorithm has been proposed.The path planning strategy which developed to overcome the collision and avoidance problem in path planning of robot is inspired by fuzzy control concept,in order to achieving a target that making robots to follow a non-collision rapid and accurate path in uncertain environment.Simulation results showed that the strategy using fuzzy algorithm could meet the feasibility and validity demand.

Abstract: Real-time accuracy of the permanent magnet synchronous motor (PMSM) parameter directly affects the performance of the servo system. In this paper, the model reference adaptive parameter identification method, the parameters of permanent magnet synchronous motor running as the actual model , the mathematical model derived from the equation of state in the d, q coordinate system as the theoretical model , in order to calculate the real-time stator resistance , inductance and rotor flux value . Thereby increasing the accuracy of the vector control .Using simulink simulation results show that, The system can quickly and accurately calculate the real-time parameters and the applied control.

Abstract: This paper proposes a stator flux and rotor speed estimation method for induction motor (IM) based on extended complex Kalman filter (ECKF). A complex-valued model is adopted that allows a simpler and more effective state estimation of IM. And a third order ECKF has been designed for IM model by neglecting the mechanical equation, which is a valid hypothesis when the motor is operated at a constant rotor speed. The stator flux and rotor speed estimation obtained from ECKF are applied for direct torque control (DTC) of induction motor. This method for state estimation is more effective and easier than the one performed on the corresponding real-valued model, as it obtains observability conditions directly in terms of stator current and flux complex-valued vectors. The proposed ECKF achieves a good performance in DTC of IM. Simulation experiment results in Matlab/Simulink environment validate the proposed method.

Abstract: NOx emission of diesel engine is an important pollutant to the environment, in the bench test of SCR technology for the diesel engine NOx reducing effect. Diesel engine NOx to ESC test cycle emission by 10.73,down to 3.24; ETC test cycle of the diesel engine NOx emission decreased from 9.533 to 2.98, the diesel engine emissions to meet Euro IV emission standards. Experimental results showed that SCR can effectively reduce NOx emission of diesel engine and the pollution of the environment.

Abstract: SSCR system is different from traditional SCR on the source of the NH₃ produced, with the method of ammonium salt decomposition into NH3, directly spraying the NH₃ into the SCR catalytic box to react with the NOx in the auto exhaust. So on the structure, new SSCR replace the Urea nozzle with a NH₃ nozzle. The nozzle flow rate is related with the nozzle opening time, frequency and the back pressure and so many other factors. So in our experiment, we completed the control strategy of nozzle opening time on Mototron platform, and using the method of drainage obtained the experimental data of the nozzle flow rate.

Abstract: A large cement factory as an example, according to the requirements of process and control parameters of production line of raw mill, this paper researches and designs the automatic control system of cement raw mill production line based on PCS7 and PROFIBUS. The design of the whole system consists of three levels: field layer, control layer and operation layer which are connected by Ethernet and PROFIBUS implementation, and focus on the design of the feed flow includeing feed composition, feed machine speed loop control etc. Through the on-site operation, the system is stable and reliable, and has good application and promotion effect.