Applied Mechanics and Materials Vols. 536-537

Abstract: Pulsed current source is used to drive high-power LED in thermal analysis and testing. A new scheme to design the high-power LED pulsed current source, which integrates FPGA device, with highly quality single-chip microcomputer C8051F as the control center, is introduced. In order to obtain the LED automatic current control, the negative feedback is used in the LED pulsed driver. The pulsed current source consists of constant-current source and couple output interface controlled by square pulse signal, which ensures the stability of pulsed current, rise time and fall time. It is convenient to adjust the pulse current amplitude, pulse width, pulse cycle and sampling gate independently. Results show that the current stability of the driver control system can obtain 0.01%.

Abstract: This paper addresses the stabilization and optimization problem of networked control systems (NCSs) with long time delays. According to the actual network conditions, the network time delay is divided into the fixed time delay and the random time delay. Then, the stabilization controller is constructed, where the stabilizing control parameters are obtained with cone complementary linearization (CCL) approach and the optimizing control parameters are solved with estimation of distribution algorithm (EDA) algorithm. Simulation results demonstrate the effectiveness of the proposed methods.

Abstract: This paper investigates a representation model, namely, a discrete-time switched fuzzy system. In this model, a system is a switched system whose subsystems are all discrete-time Takagi-Sugeno (T-S) fuzzy systems. For the proposed discrete-time switched fuzzy system is built to ensure that the relevant system is asymptotically stable by Arbitrary Switching and the Lyapunov functions method. The main conditions are given in form of linear matrix inequalities (LMIs), which are easily solvable. The elaborated illustrative examples and the respective simulation experiments demonstrate the effectiveness of the proposed method.

Abstract: This paper introduces the current development of dynamic compaction machine at home and abroad and the basic structure of no decoupling dynamic compaction machine. Besides, The design scheme of no decoupling dynamic compaction machines brake control system is focused on putting forward in order to achieve automatic ramming without decoupling and without artificial hook. This kind of dynamic compaction machine with the advantage of simple structure, convenient operation and high efficiency effectively reduces the construction cost.

Abstract: The cyber-physical systems (CPS) are large-scale intelligent complex systems by the deep integration of technology and the physical systems. The cyber-physical power systems (CPPS) are the key technology to implement the objective of smart grids, by seamlessly integrating the computing, communication and sensing technologies with the power system. The existing research of CPPS is limited to the survey. This paper firstly presents the concept of smart power object applied to CPPS, which often is a power device object adopts RFID technology to identify itself, feeds back its real-time states, and has certain coordination ability. Then, on this basis, the key technical problems of global optimization and local control based on CPPS is further studied, such as control model, construction strategy, coordination control mechanisms, and communication mechanisms. Finally, it is applied to regional voltage optimization control to implement smart optimization control in low voltage power system.

Abstract: To damp the vertical oscillations of the descent submersible caused by dusting the control system utilizing a shock-absorbing hoist located on the submersible was developed. The robust proportional-plus-integral action controller was included in the control loop to ensure the acceptable dynamic properties of the system by the interval variations of the module mass and the rope length. The parametric synthesis of the controller was carried out on the basis of the robust expansion of the coefficient method of the quality rating estimation. The system operability was confirmed by the results of the digital simulation.

Abstract: This paper presents the design of control system of direct metal deposition forming software. The system which is designed by VC++ software employs the ideas of object-oriented and data stream. The metal parts are abstracted into objects and classes to realize the reusability and scalability. The software control system has realized from the machine initialization, digital control code generation, forming process control, process parameter management module. The control system can improve the forming quality and achieve the best forming process control, saving the metal parts of the development time and cost of development.

Abstract: The paper introduces the entirety design structure of distributed pipe welding control system. According to demand of pipe welding control, we design and achieve the DSP master control node of field-control layer. The DSP master control node is transplanted by DSP/BIOS operating system, and welding function modular is divided into several independent processes, which is controlled and scheduled. To enhance speed regulating scope and response time of rotation and wire feeding module of brush DC motor, we use feedforward-feedback control mode. Aim at particularity of pipe welding environment and variety of communication data type, the communication between field-management layer and field-control layer is CAN communication. We transplanted CAN-open protocol on it.

Abstract: In recent years, the government has stepped up efforts to control coal mine. A large number of small coal mines were shut down for the simple reason that they are not up to the standards. More and more coal enterprises now put the informatization at the top of the long-term development list. In the management information system, the coal quality control is regarded as a main functional module. The traditional process of coal quality testing can’t meet the regulatory requirements. With information technology, to get faster and more accurate monitoring of coal quality and give management advice are the important content of a coal enterprise information construction. This article presents how to use the computer network technology to better control the coal quality.

Abstract: Three-phase bidirectional AC/DC converter acts as a key part in DC microgrid. To improve the stability of DC bus voltage for the grid-connected mode in DC microgrid, a sliding mode or PI controller based on SVPWM modulator is designed for the bidirectional AC/DC converter in inverter mode. When the error between grid-connected current reference value and actual value is larger than the threshold value, the sliding mode controller is used. Otherwise, the PI controller is adopted. The great grid-connected current reference value fluctuation is simulated in PSIM software when the DC microgrid operates in the grid-connected inverter mode. The simulation results show that the gird-connected current actual value can fast track with the reference value. Then the dynamic response performance of DC bus voltage is improved.