Applied Mechanics and Materials Vols. 130-134

Abstract: With the widespread use of the elevator, the shortcomings of the current elevator design become apparent. Especially the phenomenon of people being trapped in the elevator caused by accidently powered-off or some other reasons, which not only arouses much uncomfortable, but also threaten the safety of passengers. To solve this problem, an Elevator ARS (Automatic Rescue System) based on Internet is proposed and designed in this dissertation. The system is developed based on high performance MCU (Micro Control Unit), by which all status of elevators can be monitored through Internet.

Abstract: Thermoelectric cooler has dynamic thermoelectric performance under complex environment. A linear dynamic model of the thermoelectric cooler is derived using small-signal linearization method. It shows that the dynamic model of the thermoelectric cooler has one zero and two poles. The dynamic model of the thermoelectric cooler is showed to vary with operating conditions. Based of average linear dynamic model of a thermoelectric cooler, a temperature control system is designed for the cold end temperature of the thermoelectric cooler using fuzzy-PID algorithm. The step response tests show that the controller has satisfying dynamic and static performance. In room temperature environment, the response time for cooling down 18°C is around 340s and the steady error is very small. The cold-end temperature can be maintained at the setting value within 0.1°C. Experiment results also show that the setting temperature can reach to 23°C below the environment temperature, and the setting value is smaller and the step response time is longer.

Abstract: Statistical theory and fuzzy analysis are two primary methods of radar and ESM track association algorithms. Absolute-double-threshold rule was used to analyze these two association algorithms. Each algorithm was simulated in this paper. The simulation results show that both of these two track association algorithms have high probability of correct association, but the algorithm based on statistical theory has faster convergent speed and litter samples, while the other is simple, and has less calculation.

Abstract: Modern CNC system adopts the NURBS interpolation for the purpose of achieving high-speed and high accuracy performance. However, in conventional control architectures, the computation of the basis functions of a NURBS curve is very time consuming due to serial computing constraints. In this paper, a novel multiprocessor-based motion controller on chip utilizing its high-speed parallel computing power is proposed to realize the NURBS interpolation. The motion control algorithm and I/O control are also embedded in the chip to implement real-time control and NURBS interpolation simultaneously. The experimental tests using an X-Y table verify the outstanding computation performance of the multiprocessor-based motion controller on chip. The result indicates that shorter sampling time (0.1 ms) can be achieved for NURBS interpolation and high-accuracy motion control.

Abstract: Static var compensator (STATCOM) is a widely used power electronic device for dynamic reactive power compensation, and its current detecting and control method generally adopts d-q decoupling method based on the synchronous rotating coordinate transformation. However, in the traditional method, the load reactive current component is directly used as the command of STATCOM output current, so it is required that the installation position of STATCOM must be consistent with load current detecting point. But in practice, STATCOM installation point and load current detecting point may be located at two different sides of the transformer. For this situation, this paper proposed an improved reactive current detecting and control method based on the principle of power balance, achieving the current detecting and control strategies when the two points are located at different sides of transformer. Finally, the simulation of system with STATCOM accessed from the third winding of transformer verifies the correctness and feasibility of the proposed method.

Abstract: This paper presents a new approach of PID parameter optimization for the induction motor speed system by using an improved particle swarm optimization (IPSO). The induction motor speed is changed by the stator voltage controlled with PID controller. The performance of PID controller based on IPSO is compared to Linearly Decreasing Inertia Weight (LIWPSO). Simulation results demonstrate that the IPSO algorithm has better dynamic performance, higher accuracy and faster convergence and good performance for the PID controller.

Abstract: Due to some nonlinear factors and time delay in electronic throttle, the opening of electronic throttle is difficult to control. For overcoming these difficulties, in this paper a fuzzy adaptive PID controller is designed for an electronic throttle control system. The model of electronic throttle control system is built based on Matlab/Simulink and realized with a hardware-in-the-loop simulation system, which is based on MACS565. Simulation research and experiment results show that, compared with PID control system, the fuzzy adaptive PID control system, has some advantages. The all performance index with the fuzzy adaptive PID control is better than that of the PID control.

Abstract: The strategy of 4-wheel-identical-state-control is proposed on the designed 4-wheel-independent-driven electric vehicle (briefed as 4WID-EV), the working states of each wheel are adjusted to be the same through controlling the ratio of drive-force and vertical-load on them as equal as possible, the co-simulation of ADAMS and Matlab/Simulink is done about the 4WID-EV driving on the straight flat road and slopes. The real vehicle test is performed. The result indicates that the strategy of identical-state-control can control each wheel slip ratio to be equal, make each wheel working in phase, reduce the power loss, improve the vehicle power property, and achieve the aim of good driving force distribution.

Abstract: According to the collision of tower cranes working on the construction site, this paper establishes the mathematical model of the tower cranes first, and analyzes several possibilities of collisions. The model is based on homogeneous transformation, thus the distance between tower cranes which is dangerous can be calculated accurately, then the monitor will give an alarm. Based on Visual C++ 6.0, the calculation program is provided as the core of the control system. At the same time, the algorithm and methods to adjust flat arm tower cranes are introduced in this paper, and they are verified by examples through running the program.

Abstract: This paper analyses the key point of energy saving in the Wheeled Crane hybrid power system. The scheme of 25T Wheeled Crane hybrid power system is designed based on supercapacitor. DSP, PLC and Touch panel is used as the control center of the system. The design of main circuit, measurement system, PLC system and system communication and coordinate control is discussed. Finally, main circuit and system experiment results are presented. Experiment shows that this system may save energy 30% or above.