Advanced Materials Research Vols. 383-390

Abstract: This paper presents a new strategy of direct torque controller for bearingless induction motor using space vector pulse width modulation based on fuzzy adaptive control. when we use direct torque controller using space vector pulse width modulation to take decoupling, the parameters of PI controller which generating the reference voltage vector in conventional SVM-DTC are difficult to determine the dynamic operation. In order to improve away the disadvantages of conventional SVM-DTC system, flux and torque fuzzy adaptive controller were designed to substitute the original flux and torque PI controller in the controlling for bearingless induction motor using space vector pulse width modulation. With the fuzzy algorithm, it is easy to obtain the control voltage component of the flux and torque respectively. Two voltage vectors achieve real-time adjustment and solve the disturbance problems in torque loop and flux loop. In this paper, the design process of the fuzzy adaptive controller is given. Use Matlab/Simulink to check the improved and traditional SVM-DTC method. The results show that the improved algorithms have a better performance in reducing the ripple of torque, flux and Rotor displacement when compared with the tradition DTC method. And it also improves the system dynamic performance.

Abstract: Designed the control system policy for automobile electric seat using fuzzy control technology, therefore established its control model by Fuzzy Logic Toolbox, and carried on the off-line simulation to choose controller's optimum control parameters. From the dynamic viewpoint, the auto electric seat adjustment system is not only a complex nonlinear function which includes the location of the DC servo motor and the speed, but also contains serious nonlinear coupling interference, so the system is a highly nonlinear strong coupling, variable multivariable system. Application of traditional control methods (such as traditional PID) is difficult to meet its order requirements, so the research is highly robust method of intelligent control is an effective way to solve the problem. Fuzzy control technology has become the field in which drawn greater attention and researched in recent years. It doesn’t depend on the mathematical model of controlled object, has a good robustness, and nonlinear control characteristics, so it is an effective means to control the object with time-varying, non- linear parameters. In this paper, fuzzy control technology to achieve the orders of auto electric seat adjustment control system functions in the Literature [1], and the tracking of the system was simulated.

Abstract: In order to ensure the machining precision of wedge nonaxisymmetric aspheric lens, a parallel grinding method is designed using a clamp with adjustable gradient. Based on the machining method, three path plans of machining are put forward. Simulation results show that the three methods have their particular advantages according to the different requirement of machining

Abstract: The Fuzzy control method in an automobile Electronic Control Braking System (ECBS) on varying pavement is studied. According to the characteristics of an automobile ECBS which adapts to the varying pavement, the ECBS fuzzy control system is established. The ECBS fuzzy controller based on slip is designed. When the automobile is braking on uniform pavement and varying pavement, the computer simulation is fulfilled for the deceleration threshold value control and the slip fuzzy control of the automobile ECBS by using MATLAB/Simulink. The results show that the automobile ECBS using fuzzy control can obtain better fundamental braking performance on varying pavement, wheel locking doesn’t appear, both braking distance and braking time are short, the fluctuation of the wheel periphery velocity is little and smooth, its braking performance is obviously better than the deceleration threshold value control.

Abstract: In this paper, we propose a mechanical structure for multi-legged robot. Referring the request of control system, we also made a proper choice on driving means. After dynamics analysis on a single leg of the robot, we make a simulation using ADAMS and get how the torque of each joint is changing when the robot is walking. The model of DC motor is established for the control system. Fuzzy PID controller was used to get real-time response and high accuracy of control system.

Abstract: Based on analysis of characteristics and develop trend of fixture design, the functional structure of service platform for networked manufacturing has been put forward. Information integrating technology, networked manufacturing service technology, and collaborative work technology has been researched in detail. The feasibility and practicality of functional structure of service platform for fixture design and manufacture has been verified by development and preliminary application of the service system.

Abstract: This paper models EGCS based on the analysis of EGCS structure, and furthermore, writes modularized program utilizing Matlab C-mex language. The paper also sets up a simulation platform in the Matlab/Simulink simulation environment to perform the group control simulation of 4 20-floor elevators based on the minimal waiting time group control algorithm. With testing, the result of the testing shows that the research platform can satisfy the research requirement of the Elevator Control Strategy.

Abstract: The propagation of scattering Lamb wave in plate was simulated using transient dynamic analysis in ANSYS. In order to extract the characteristic information of received signal for damage identification, the short time Fourier transform based on time-frequency analysis was utilized, and then the energy distribution and envelop of received signal were obtained. Based on the displacement contour of simulation and energy distribution, the propagation of scattering wave in plate with a through hole was examined. Also, a mathematic relationship between damage location and scattering signal was developed, with the help of wave propagation path through actuator, damage and sensor. A nonlinear optimization method was applied on the mathematic relationship to obtain the damage location. The damage identification method using scattering Lamb wave was therefore established.

Abstract: A new method, obtaining the pressure-time relations during air inflation and deflation process, is proposed to research the dynamic characteristic of a pneumatic solenoid valve. The current, magnetism, mechanical and air subsystems of the valve are investigated. In order to experimentally verify the advantage of the new model, two models are compared. Simulation results show, the opening and closing reversal times of the model without air subsystem are 29.6ms and 30.7ms. The new model’s reversal times are 31.8ms and 36.1ms. 32.5ms and 35.3ms are the results by experiments. The experimental results show very good agreement with the new model.

Abstract: According to the nonlinear, multivariable and multi-constraint features of the reentry trajectory optimization problem of airbreathing hypersonic vehicles, a suboptimal solution method is developed. The reentry trajectory generation is converted to a nonlinear programming (NLP) problem by using Gauss pseudospectral method (GPM). The state and control variables on Gauss nodes are chosen as parameters to be optimized and the minimum total heat absorption is chosen as the optimal performance index. Then the sequential quadratic programming (SQP) method is used to solve the NLP problem. The states of optimized trajectory are compared with the states obtained by the integral of kinetic equations. By simulating on an example of airbreathing hypersonic vehicles, it is demonstrated that the above method is not sensitive to the estimate of motion states and is easier to converge. And the method is effective to solve trajectory optimization problems.