Abstract: The Magneto-rheological (MR) dampers are favorite mechanical system in dynamic structures. This paper presents an application of Wiener-type nonlinear models for describing the hysteresis behaviors of MR dampers at different operating conditions. In this structure, a linear part consisting discrete-time Kautz filters is cascading by a nonlinear mapping function (feedforward neural network (FFNN)). The pole parameters of Kautz filters were chosen with respect to the poles of best fitted linear model on real system. By defining the parameters of Kautz filter, the nonlinear behaviors of system were identified using neural network model, as the output of filters were considered as the output on NN. In order to assess the performances of the developed models a comparison between the responses of the models and another recent modeling approach was preformed.
Abstract: Laminar natural heat transfer in the horizontal channel with a heated square cylinder has been studied by using lattice Boltzmann method. Air and water are applied as fluid flow and the walls of channel are adiabatic. Lattice Boltzmann method (LBM) as one of stochastic methods has been used to study the hydrodynamic and thermal behaviours of water and air, with Prantle number 7.01 and 0.71, respectively. Velocity and temperature profiles are achieved near each surface of the square. The results show relation between Prantle number and symmetric degree of streamlines and isotherms profile
Abstract: Improve stability and reliability of machine components has confirmed the necessary needs of using advance materials such as polymers and composites. Specific characterization of polymer materials can improve the altitude of products design by increasing the mechanical feature of structures such as high fatigue strength, longer life and etc. Polymers are known as hyperelastic materials with a complicated mechanical behaviour. An acceptable mechanical analysis of three dimensional (3D) polymer structures depends on a true understanding of applied model on computational methods such as Finite Element Method (FEM). This study focused on stress and deformation analysis of 3D polyethylene polymer panel under three-point bending test using FEM. Explicit dynamic procedure has been used to examine the mechanical behaviour of polymer beam. Two tests of tension and compression is performed on polymer specimens to extract the material properties and used in finite element model. The specimen panel selected thick enough to generate two complicated situation of tension and compression zone while it is under bending load condition. The test was performed to extract the actual response of the specimen by plotting the force-deflection curve and stiffness of structure. The experimental data confirmed well the simulation results and states the accuracy of the analysis process. A discussion is given on effective stress and deformation generated in the polymer panel. A Complex deformation observed at the middle of specimen behind loadcell, that signifying the effect of geometry and boundary condition with respect to hyperelestic behaviour of polyethylene. The computational procedure is recommended for mechanical analysis of polymer structures due to the capability of the model for accurate prediction of hyperelastic behaviour.
Abstract: As an application layer protocol of CAN bus, CANopen has wide application in industry. This paper presents a kind of CANopen slave node based on AVR hardware platform of AT90CAN128. Firstly the structure of the slave node hardware platform of the AVR microcontroller AT90CAN128 and CAN bus control based on embedded CAN driver module CTM1050 is proposed. Then the open-source protocol stack CANFestival software design and the specific method are described. CANopen network testing platform is built to test the design of the CANopen slave node. The experimental results illustrate that the proposed solution and implementation method is correct and effective.
Abstract: PD state-feedback controller has been adopted in many spacecraft for attitude tracking and presents good performance. For flexible spacecraft, the controller can be designed with a term which takes into account the flexible dynamics. However, duo to nonlinearity and coupling, how to determine state-feedback control parameters which ensure fast attitude tracking and significant vibration suppression must be considered. In this paper, the dynamics model of spacecraft with flexible appendages is derived with the hybrid coordinate method and the full state feedback controller originated from the PD control algorithm is designed. A method of estimating the flexible spacecraft's controller parameters based on the particle swarm optimization (PSO) algorithm is presented. Taking the PD controller parameters as optimized variables, optimal control state is defined as the linear weighted sum of response error of all state variables is smallest with the limited actuator output moment. Simulation results show that the optimized controller obtained by PSO algorithm makes attitude of spacecraft converge quickly and elastic vibration suppressed effectively.
Abstract: Car dumper is an important material transport equipment which has characteristics such as large structure, heavy duty, low frequency operation, stop-and-go and recurrent excursion of machine barycenter. This paper researched implementation of synchronization control. A fuzzy controller is added between two channels of dual drive subsystem. Based on coordinated control principle and achieving the goal of difference minimum of corresponding state of two subsystem, a fuzzy correction control program using in-phase error non-uniform common feedback is adopted to make the output of two synchronous subsystem consistent basically, which increase response speed of system to synchronous error, reduce synchronous error of dual drive subsystems effectively, ensure the consistency of car dumper dual drive, solve the recurrent mechanical failure caused by inconsistency of dual drive and enhance the steady reliable operation of car dumpers. The synchronization control strategy presented by this paper provides favorable guarantee for synchronization precision of multi subsystem in large rotary equipments and at the same time explores new ideas for other synchronization control systems.
Abstract: A sliding mode controller for flux-switching permanent magnet (FSPM) motor is investigated in this paper, in which direct torque control (DTC) concept, variable structure control are integrated to achieve high performance. Then, an FNN is investigated to optimize the control gain matrix of sliding mode controller. The theoretical analyses for the proposed FNN sliding-mode controller are described in detail. Simulation results show that the proposed FNN sliding-mode controller provides low torque ripple and the chattering phenomenon is much reduced.
Abstract: A vehicle monitoring and dispatching system based on GPS and GPRS technologies is designed in this paper. This system communicate with server, upload GPS information and timely response to the various instructions issued from server through the Socket, and the position of moving vehicle is shown in the electronic map in the monitor center. Various control instructions issued by the server to achieve the remote monitoring of the vehicle, the real-time controlling of the multbvehicle system is achieved.
Abstract: In this paper, a new approach for increasing the sensitivity of the bulk silicon electrothermal actuators is reported. And the bulk-Si MEMS electrothermal actuators are fabricated on the CMOS substrate by a novel and simple post-CMOS process. Through this technology, the substrate isolation and electrical interconnection between the CMOS circuits and MEMS sensors are achieved perfectly. The measurement results show that the sensitivity of the modified electrothermal actuators is about 6 times higher than that of the non-modified electrothermal actuators. And the sensitivities (non-linearity) of the modified and non-modified electrothermal actuators are 20.23μm/V (0.865%) and 3.34μm/V (0.37%), respectively. Furthermore, the finite element software ANSYS was used to verify the design and the models of the electrothermal actuator. The electrothermal actuator was characterized under the 3D microscopy.
Abstract: At present in China control strategy and control plan of highway monitor system are realized by collecting traffic environmental information, analyzing and processing by computer technology, publishing induction or banned instructions automatically and uniting the overall coordination of the road network traffic operation. In recent years in some provinces monitor plans of the whole distance have been started and monitor strategies of the whole distance have been made completely in order to make highway transportation safer, more open and more comfortable. With the help of the engineering experience and the characteristics of control strategy and control plan of highway monitor system in some provinces and cities ,I study the control strategy and control plan of highway monitor system and in detail analyze four cases that are the traffic flow control plan, the traffic incident control plan, the meteorological environment control plan and the emergency phone alarm control plan by research on the control method, the control process, the facility linkage control and the control result.