Applied Mechanics and Materials Vols. 278-280

Abstract: This paper is concerned with the controllability of switched linear fractional control systems, and the solutions of expression, necessary and sufficient conditions for the controllability of systems are given later.

Abstract: In this paper, the magneto-rheological damper is installed in the seat, using semi-active control theory and methods, dynamics mathematical model of the magneto-rheological damper seat is established, the fuzzy semi-active controller based on the magneto-rheological is designed, and then the simulation analysis on the system is completed by the software of MATAB/Simulink. The results of simulation show that the semi-active seat based on the magneto-rheological can markledly suppress the vibration acceleration and improve the ride comfort of the seat.

Abstract: Hydraulic turbines are known to have complex and highly nonlinear dynamics with some varying parameters, especially in the presence of large or abrupt disturbances. In this study, the weighted multiple model adaptive control scheme was used as a controller for a hydraulic turbine model, with the aim of providing desirable characteristics such as robustness and stability. The system of comprised four candidate plant models with four corresponding candidate PID controllers which were tuned according to the phase shifting method. The plant operation, subjected to both abruptly changing and smoothly changing load conditions, was simulated. From the results, it was found that the proposed controller showed very good performance for both types of disturbance changes.

Abstract: Generator terminal supplement damping control (GTSDC) is an effective method to damp the sub-synchronous resonance. In this paper, the real time closed loop testing technique of GTSDC is studied. The four kind of performance test is discussed. They are characteristic valuation of GTSDC, model contrast of GTSDC and real-time digital simulation (RTDS), GTSDC coordination with the excitation damping control, and robustness analysis of GTSDC. The testing results show that the real time closed loop testing technique of GTSDC is effective and reliable.

Abstract: Vehicle tracking plays more important roles in modern transportation and logistics operation. This paper deals with a new approach to track vehicles based on RFID (Radio Frequency Identification) technology. The basic steps of vehicle tracking based on RFID are introduced and a six-layered architecture for the vehicle tracking system integrating databases, RFID tags, RFID readers, data centers, networks and user interface is presented, where the positions of vehicles are attained directly by compared the RFID readers collecting vehicle RFID tags with their position information in the database. It is shown that this vehicle tracking method uses RFID more fully, the architecture with clear levels, adapts to the future technical and practical requirements, and can help fuse more complicated applications like intelligent charging and cargo tracking.

Abstract: The controller is designed with LPC2132. The working state of motor and pump can be judged by detection of the Pump station’s power supply voltage, working current，temperature of the motor and pump, water pressure and so on. In order to protect the motor and pump, the motor should be stopped immediately when they work abnormally, then the abnormal phenomenon will be transferred to the director by remote data and corresponding remedial measures will be taken in time. The system achieves not only remote data transmission but also remote controlling. It has being used in many places, the result shows that the control system can be operated steadily and reliably, so it has a good application prospect and promotion value.

Abstract: Correct identification of system parameters contributes to construct more precise model of the system and therefore improves the performance of controller. The current identification algorithms have some disadvantages, such as the complication of algorithms and the high requirement on hardware. In this paper, we propose a new system identification method which only utilizes the data from serve motor encoder. Based on the differential equations of motion and the theory of undetermined coefficients, mechanical parameters of the system can be solved using the least square method with the equations constructed based on kinematic parameters obtained by experimental tests. The identified mechanical parameters are then used to construct the system transfer function and a SIMULINK model. The method is validated by comparing the results between simulation and experiment. This method has advantages of low requirement on hardware and simple algorithm. It is proper to be applied in mechanical parameter identification of servo system.

Abstract: In order to improve the tracking accuracy of the synchronous radar network under blanket jamming with less computation, a new target tracking algorithm based on the optimal linearization is proposed. Firstly, the optimal linearization algorithm for the measurement equation is analyzed. Then the optimal estimation of the position is derived in 2D space according to the bearing angle measurements, and then the estimation is expanded to 3D space in accordance with the pitch angle measurements. Finally, the tracking algorithm for the moving target is presented and simulation testing is conducted. The simulation results show the tracking algorithm without iteration proposed by this paper can make it possible for the radar network under blanket jamming to track the target precisely.

Abstract: Path pre-planning generate the feasible conference path between start and destination for UAVs, it relates to restrictions from UAVs itself and environment information. Generally, the path is produced by searching in configuration space with some intelligent searching algorithms, the space is always so huge that it is difficult to obtain high efficiency, even lead to NP hard. We proposed a fast 3D path pre-planning method which plan 2D path firstly and then process height planning based on obtained 2D path, considering typical constraints such as turning angle, climbing/diving angle and static threat avoidance. Fast Marching Method (FMM) and Sparse A-Star (SAS) searching method are used in the course of 2D path planning and height planning respectively, Experiments showed that the proposed method generates path quickly, the obtained path follows terrain and avoids obstacles well.

Abstract: Multi-model (interactive multi-model )tracking is an effective method for maneuvering target tracking, and turning model is widely studied and applied in multi-model tracking modeling and model set establishment. A detailed study is carried out on the self-adaptive turning model modeling method for maneuvering target tracking. Also a summary is made about the method of establishing tracking model by calculating the turning rate. The shortcomings of literature [4、6]'s self-adaptive turning model in actual application is also pointed out, with two modeling methods adopting average turning rate presented accordingly. The simulation test proves the necessity of improvement and the validity of the new model.