Advanced Materials Research Vols. 139-141

Abstract: That the dynamic model is characteristic of nonlinearity and that linear equation design approach based on small perturbations of linear system has failed to meet the design requirements cause the study of the dynamic inversion control. Integrating the dynamic inversion theory and the UAV nonlinear mathematical model, the paper, in accordance with the speed of status variable change, has designed respectively the UAV inner-loop fast variable and outer-loop slow variable controllers and thus, found the dynamic inversion flight control law applicable to UAV and conducted the simulation study. A conclusion can be drawn that the control law is satisfactory in flight control.

Abstract: A self-constructing fuzzy neural network (SCFNN) based on reinforcement learning is proposed in this study. In the SCFNN, structure and parameter learning are implemented simultaneously. Structure learning is based on uniform division of the input space and distribution of membership function. The structure and membership parameters are organized as real value chromosomes, and the chromosomes are trained by the reinforcement learning based on genetic algorithm. This paper uses Matlab/Simulink to establish simulation platform and several simulations are provided to demonstrate the effectiveness of the proposed SCFNN control stratagem with the implementation of AC motor speed drive. The simulation results show that the AC drive system with SCFNN has good anti-disturbance performance while the load change randomly.

Abstract: This paper introduces mechanics and electronic coupling mode of piezoelectric intelligent structures, and discusses the key technology and potential prospect of intelligent structures in application of vibration control. A multiple-input multiple-output transfer function model of piezoelectric plates is derived and an analogy for modal control between the piezoelectric structures and general ones is established. A concept, "piezoelectric vibration modes", is presented. Based on this concept and by experiment development, a "quasi-independent modal control" technique is presented, attempting to approach, with hardware as simple as possible, independent modal control. The experiment progress and results for multiple modal damping control show its effectiveness and practicality. The modal damping of piezoelectric intelligent structures can be increased enormously. They have good advantage and potential prospect in application of structure vibration control.

Abstract: The necking-in product is widely used in many fields in the world. An improved necking-in machine is introduced in this paper. Matlab/Simulink is the popular simulation software in the dynamic system simulation field due to its powerful computing capability. DSHplus is the hydraulic special simulation software with graphical programming environment and abundance of model libraries and the system model can be built quickly. The co-simulation of DSHplus and Matlab/Simulink can take the advantage of their merits, which can study the control algorithm that applied on the hydraulic proportional system better. The Fuzzy PID control algorithm can apply logistic inference to tune the PID parameters automatically according to the working condition, which can solve many engineering problem of high performance requirements. So the Fuzzy PID algorithm is applied in this paper to improve the performance of the hydraulic system.

Abstract: Many researchers have indicated that standard genetic algorithm suffers from the dilemma---premature or non-convergence. Most researchers focused on finding better search strategies, and designing various new heuristic methods. It seemed effective. From another view, we can transform search space with a samestate-mapping. A special genetic algorithm applied to the new search space would achieve better performance. Thus, we present a new genetic algorithm based on optimal solution orientation. In this paper, a new genetic algorithm based on optimum solution orientation is presented. The algorithm is divided into "optimum solution orientation" phase and "highly accurately searching in local domain of global optimal solution" phase. Theoretical analysis and experiments indicate that OSOGA can find the "optimal" sub domain effectively. Cooperating with local search algorithm, OSOGA can achieve highly precision solution with limited computing resources.

Abstract: Based on the dynamic mathematical model of induction motor, the mutual model reference adaptive system method (MRAS) for rotor speed identification is proposed to implement a speed sensorless direct torque control. The model reference adaptive theory is flexibly used in the rotor speed and the stator resistance online identification. The reference model and adjustable model used in the mutual MRAS scheme are interchangeable. Therefore, the control system can obtain high-precision speed identification. Simulation results show the method can solve the problems of speed control accuracy and system stability under the influence of motor parameter variation. The low speed performance of DTC is also improved.

Abstract: This paper studied the real-time performance of three-tier client/server architecture used in remote monitoring system. A scheduling algorithm was adopted in middleware of this architecture, which based on the regulation: setting the priority of task according to the percentage of useful data in the data-buffer or the LAD (most locally available data first) but not according to the earliest deadline. Contrast simulation of the improved algorithm and EDF (earliest deadline first algorithm) had been achieved from program developed using VC++ at different average task lengths and update workloads under the tentative parameters such as the size of data in different data-buffer, the time used for fetch an object from these data-buffers and average task inter-arrival time. The results showed that the LAD’s completed task percentage before deadlines was higher than EDF, which proved LAD was more suitable to improve the real-time performance of three-tier client/server architecture.

Abstract: Intelligent wheelchair system (IWS) is a potential selection for the elderly and disabled people to improve and enhance the quality of their daily lives and work. Based on the theory of collaborative Kansei engineering, a new intelligent wheelchair system has been developed. The system integrates the advanced Kansei characteristics of human such as affections, feelings, emotions, etc, to the wheelchair system. This new IWS is very comprehensive, creative and humanized. Modern wheelchair with the IWS helps to add recognition, understanding, and cooperative communications between the elderly and disabled people and the wheelchair system.

Abstract: An improved dynamic Grid-based potential field method was proposed based on the consideration that the goal, robot and obstacles in robot soccer compete are all dynamic. We combined the advantages of potential field method and the grid method, set the grid method to represent the environment, and got dynamic potential function in the potential field method. We used dynamic potential function to form the inspire function of the search algorithm A* which is used for the search of adjacent nodes. The dynamic Grid-based potential field method meets the real-time planning requirements in the complex and dynamic environment. And it has received very good results in solving the local minima problem of the traditional potential field and improving the planning efficiency. It is better in security and reliability. Simulation results show that the method is feasible and effective in soccer robot path planning.

Abstract: Nowadays, some kinds of the photoelectric stable platforms have applied the digital controllers. In the course of designing the digital controllers, designers usually depended on the personal experience or the rough mathematical models. As a result, designers spent a long time regulating the control parameters in order to obtain better control performance. Therefore, it is very important and necessary to establish the precise mathematical model for the photoelectric stable platform system before designing the digital controller for it. In the paper, firstly, using principle analyzing method establishes the common analog mathematical model for it. And then, the parameter estimation methods of the parameters to be determined are discussed from two aspects of the time domain and the frequency domain. These lay a good foundation for implementing the effective digital controller designing for the photoelectric stable platform system.