Advanced Materials Research Vols. 562-564

Abstract: Aiming at ac motor closed-loop control difficult, a frequency conversion system was designed base on PLC and fuzzy algorithm. This paper deals with a PLC and frequency converter controle AC induction motor method, as well as constructed two-dimensional fuzzy controller by PLC, realize the dynamic control of nonlinear systems, avoiding the complexity of modeling, improve the system stability and anti-jamming capability. On-site testing shows that this system has a high intelligence and better robustness, can frequency control of motor speed accurately.

Abstract: EtherCAT fieldbus is widely used in the NC field for its superior performance. Based on ADX CNC, a pure-software open CNC system designed by Amoy Dynamics (Xiamen) CO., LTD，this paper comprehensively compares VersioBus with EtherCAT which are two communication platforms supported by ADX CNC and explicitly introduces the application of EtherCAT fieldbus in pure-software open CNC system with a real example. The application results show that the system is stable, fast response and high precision.

Abstract: Vehicle reference model with two degree of freedom and multi-body vehicle dynamic model are set up at first. This paper presents a Fuzzy control strategy to deal with the nonlinear, time-varying characteristics of the system, which can control the feedback of yaw rate and side slip angle. The simulation results show that the Fuzzy control method can remarkably enhance the handling stability and safety of the vehicle in complex road and driving conditions.

Abstract: Because both of the volume and the weight of the photoelectric platform are small, the structure of two frames and two axes is used in the photoelectric platform. As the key component of the photoelectric platform, the main frame should have sufficient strength and rigidity. In order to achieve this object, three-dimensional entity model of the main frame is established using CATIA software. Then the finite-element analysis of the model is finished with ANSYS Workbench. Based on the analysis results, the weak links of the main frame is found. Then these links are improved and the main frame is analyzed again. After improving the structure, the results of the finite-element analysis show that the main frame meets the requirements of design and has perfect overall performance.

Abstract: It is crucial to measure dust concentration precisely, but it normally varies with changes of working conditions. To increase precision and on-line performance of coal dust sensor, an adaptive pattern recognition algorithm was presented. The signals of unitary angular spectrums were chosen as the adaptive eigenvector for pattern recognition and pattern bank was established in advance. Furthermore, the ratio of the sum of inner signals to that of outer signals about the diffraction angular was considered as the eigenvector of subclass pattern classification. After classification, pattern could be recognized easily and rapidly. Subsequently, number of detailed patterns within different pattern groups was increased reasonably. The errors of total coal dust and respiring coal dust decline from 6% to 2.5% and from 9% to 3%, respectively. As a result, the precision of sensor achieves 95% during the measurement. It can be concluded that the adaptive pattern recognition algorithm is effective to improve the precision and real-time performance of coal dust sensor.

Abstract: The variation law of the average temperature with time in general case is derived by the differential equation of heat conduction which it is the reflection of the conservation of energy principle. The expression of the average temperature under the second boundary condition is given by the integral form of initial and boundary conditions. And what can be also derived are that the average temperature has a linear relationship with time when the boundary heat flux is constant, and it does not change with time under the adiabatic boundary condition.

Abstract: The inverse problem of parameter identification is deal with by minimizing an objective function that contains the difference between observed and calculated dam displacements. The optimization problem of minimizing objective function is solved with genetic algorithm. The calculated dam displacements are simulated by using finite element method according to water level change acting on dam upstream. The practical dam displacements are observed on the dam crest. The investigation shows that the forecasted dam displacements agree well with observed ones. The effectiveness of proposed inversion procedure is validated.

Abstract: Modern signal processing method is employed to peak resolution for four kinds of classical Tibetan Medicine X-ray diffraction patterns.Characterizing crystal diffraction peaks with Guass-Cauchy composite function, and combining with seventh polynomial characterizing the non-crystalline peak, the nonlinear least square method are adopted for peak resolution of Tibetan medicine XRD pattern. The result shows good handling effects of peak resolution.

Abstract: A novel model predictive control method was proposed for a class of dynamic processes with modest nonlinearities in this paper. In this method, a diagonal recurrent neural network (DRNN) is used to compensate nonlinear modeling error that is caused because linear model is regarded as prediction model of nonlinear process. It is aimed at offsetting the effect of model mismatch on the control performance, strengthening the robustness of predictive control and the stability of control system. Under a certain assumption condition, linear model predictive control method is extended to nonlinear process, which doesn’t need solve nonlinear optimization problem. Consequently, the computational efforts are reduced drastically. The simulation example shows that the proposed method is an effective control strategy with excellent tracing characteristics and strong robustness.

Abstract: The non-fragile robust H∞ controller was designed for a class of uncertain switched systems with delayed perturbations under additive perturbations of controller gain. A sufficient condition for the solvability of the non-fragile robust H∞ controller via state feedback was proved and presented, which based on a proper Lyapunov function and switching strategy, non-fragile robust H∞ controller can be obtained only by solving linear matrix inequalities. The systems under actions of the given controller are not only robust but also satisfy H∞ performance when controller changes, and thus have better adaptability against variety of the environment parameters. The simulation results show the effectiveness of the design method.