Applied Mechanics and Materials Vols. 336-338

Abstract: According to the problem of nonlinear and uncertainty in robot control, this paper proposes a PID control algorithm based on CMAC neural network model, for the elimination of the influence of uncertainty caused by robot system parameters and external disturbance. The simulation results show that this algorithm can effectively overcome the uncertainties and external disturbance of robot system model, this algorithm has good robustness and stability, its performance is superior to the traditional PID control algorithm.

Abstract: Using the energy estimates and Gagliardo-Nirenberg type inequalities, the uniform boundedness and global existence of solutions for a predator-prey model with Holling IV functional response with self- and cross-diffusion are proved.

Abstract: In order to analyze the dynamic characteristics of the concrete pump closed type hydraulic system in the process of pumping, we add two speed sensors and power units in the system, to achieve the dynamic loading of the pumping load by judging the main oil cylinder speed. We also establish the concrete pump closed type hydraulic system model for the dynamic simulation. The results show that in the process of pumping, pumping pressure keeps constant value and no pressure impact. Meanwhile the piston displacement linearity increases or decreases and the piston velocity keep the constant value.

Abstract: Taking pure electric vehicle as object, it has been studied for the temperature and over-current in power system of electric vehicles under different working conditions firstly, the sensor location selected also be analyzed. Based on BP neural network method, the tipping point of spontaneous combustion has been estimated through simulation, and the results show that this approach is effective.

Abstract: Firstly, the current situation of China and the necessity of importing virtual simulation technologies in production manufacturing were analyzed. And then, virtual simulation, Virtual manufacturing and their advantages were introduced. After that, the current developments of the virtual simulation technology at home and abroad were reviewed. Based on the analyses of the advantages of the current researches, virtual simulation technology existing issues and improving approaches were pointed out. Finally, the development direction was proposed.

Abstract: This paper constructs a coal-conveying control system based on programmable logic controller (PLC), which is applied to the residual heat and pressure integrated energy-saving technological transformation projects, and realizes the performance of security, reliable and efficient operation. This control system consists of the PLC control system, computer control system and industrial television monitoring system. After more than one year of actual operation shows that the system structure is reasonable, reliable operation, at the same time, reduce labor intensity, improve the utilization rate of equipment, the stable operation also provides a practical reference for other similar projects.

Abstract: In the photovoltaic power generation systems, photovoltaic battery output characteristic effect by the illumination intensity and environment temperature is very big, and has the obvious nonlinear characteristics. Therefore, it is necessary to photovoltaic battery maximum power point tracking control. This paper gives a brief introduction to the characteristics of photovoltaic battery, and puts forward an improved maximum power tracking control method, through the simulation experiments prove that the of validity this method .

Abstract: In order to analyze the contact stresses between dowels and surrounding concrete in the dowel-jointed cement concrete pavement, the 3-D finite element model is used to simulate the stress concentration in concrete around the dowel bars under traffic loading. The stress and strain responses on the concrete surface have been calculated and they are also verified with self-design full-scale experiments. Results show that the strain data from the numerical simulation agrees well with the full-scale experiment. As a result, the research indicates that the 3-D finite element model is an efficient and accurate method to calculate the interaction characteristics between dowel bars and surrounding concrete. Besides, the high press stress concentration on the concrete up dowels and the tensile stress concentration on the concrete besides dowels will cause the initial crack development in the concrete material surrounding the dowels, which is the main reason leading to the dowel bar deterioration. In this paper, a more concrete and detailed numerical analysis method will be provided to analysis the stresses concentration at steel-concrete interface in the concrete structure.

Abstract: In the past decade, developing solid oxide fuel cell (SOFC) systems for micro combined heat and power applications (micro-CHP, 1-10 kW_e) is one of the hot spots in the world energy field. To meet the requirements for system optimization and control design of SOFC micro-CHP systems, in this paper a dynamic model of an SOFC micro-CHP system is developed, based on which dynamic simulations are also carried out. Simulation results show that the present model can reflect the behavior of the SOFC micro-CHP system quite well; the influence of one component on another is an important factor to determine system dynamic behavior; as the system comprises many components and concerns different physical and chemical processes, it has dynamic processes with several kinds of time scales; for the air preheating need, the heat-exchange area of air pre-heater is quite big, which leads to its big thermal inertia, and causes the dynamic process lasting for several ten thousands of seconds.

Abstract: The scene graph structure of Fischer-Tropsch synthesis (FTS) was constructed. In the meanwhile, the assembly unit model of equipment was designed. The main FTS reactor and its mathematical physical model were described. Platform for chemical process simulation was established, on base of the virtual assembly for FTS. The method of data transfer in common chemical process simulation was proposed. The composition and flow rate of components, as well as the temperature and pressure of the FTS reactor was investigated by the one dimensional quasi homogeneous model. The relative error is less than 3% between the calculation and experiment. The accuracy of the system process simulation is reliable. It is verified that the simulation method of chemical process is feasible on base of the virtual assembly. This work studies a new way for simulation of the FTS, and also provides technologic supports for the simulation of chemical process based on virtual assembly.