Applied Mechanics and Materials Vol. 415

Abstract: This paper introduces fire supervisory system design based on embedded system using by ARM9. Embedded technology and field bus technology are used for the system design. The system can realize detecting on-line. Showing uninterruptedly the information for fire monitory point of the building, the working current for electricity lines, the leakage current, as well as environmental temperature parameters e.g., through the LCD panel. Through this system The fire information of the building and the electrical wiring or the change, fault and abnormal condition for fire danger parameters of the equipment can be mastered at any time, and the hidden fire danger can be found in time, eliminating the hidden fire danger through the alarm and terminal linkage device.

Abstract: This paper presents the development of a two-master-slave manipulator arm with force reflection for miniature tasks operation. The configuration of the two-master-slave arm is shown and the dynamic model of the slave arm is analyzed. The PID controller with the gravity compensation is selected for controlling desired positions of slave-tool-tips. The movements of the slave arm can be specified with coarse and fine motion. For the coarse motion, the slave arm will be moved approach to a specified workspace area with low precision but high speed. For the fine motion, the slave arm will be controlled with low speed so that the operator feels more confident to move the slave arm, through the master arm, with higher precision within the specified workspace. While operating the manipulator system, the operator can turn on/off the virtual fixture to command force reflection at the master arm for preventing a collision between the slave arm and the obstacles inside the specified working space. The experimental result is shown that the manipulator system is able to be used in miniature tasks operation with 1 millimeter precision.

Abstract: Low voltage ride through (LVRT) is regarded as one of the biggest challenges in photovoltaic grid equipments designing, manufacturing and control technology. The fast and accurate automatic phase locked control is the premise to achieve photovoltaic grid low voltage ride through. Considering that the traditional phase locked loop method is difficult to adapt the performance requirements of low voltage ride through (LVRT) in three-phase three-wire photovoltaic grid system, this paper presents a new three-phase unbalanced phase locked loop method. Improved second order generalized integral orthogonal signal generator (SOGI-OSG) is used for line voltage detection; Synchronous reference frame for phase locked loop (SRF-PLL) is used for line voltage phase locked and phase angle detection; Heron formula and Sine theorem is adopted to calculate the three-phase phase voltage amplitude and phase angle. Research results show that when grid voltage dips, this phase locked loop method can detect the fault signal accurately. It provides a technical support for photovoltaic grid low voltage ride through system.

Abstract: For the traditional operation mode of high strength, low efficiency in the process of the plastic ruler screen printing, the powerful PLC is used as the control core, the automatic PLC control system is developed, and the reasonable programming skills are applied so that the two institutions can work in parallel, which greatly improves the production efficiency. At the same time, sophisticated sensors are used to detect each action execution state so as to ensure that work is reliable with stable performance. Through actual production test, the printing speed has reached the capacity of 28 rulers on average per minute, and has achieved the good production benefit.

Abstract: On the verge of exhausting fossil fuels, solar energy is the one of best options for the primary source of energy as it is renewable, eco-friendly and safe to use. An intelligent solar tracker will attempt to navigate to the best angle of exposure of the sun ensuring that the maximum amount of sunlight strikes the panel throughout the day. The main reason for pursuing this paper is to establish the idea that a tracker aided array of PV modules produces more power over a longer time than a stationary array with the same number of modules.

Abstract: A distributed numerical control (DNC) strategy for error compensation on Fanuc and Siemens CNC machine tools is proposed. A DNC network is built in multi-Fanuc CNC machine tools and the error compensation of all the machine tools is realized simultaneously. A human machine interface (HMI) is developed for Siemens 840D CNC machine tools, error components are decoupled in the X, Y and Z directions and they are compensated by 840Ds own function of thermal error compensation. Experimental verification is conducted and it proves that the proposed DNC strategy for error compensation is an effective and precision manner to improve the accuracy of machine tools.

Abstract: This paper describes a hydrostatic bearing to maintain the oil film thickness, which integrates the hydraulic servo control technology. This study has designed the different intelligent nonlinear controllers by using a non-contact displacement sensor to feedback the oil film thickness of the bearing. This study proposes a fuzzy controller, a self-tuning fuzzy controller and a self-tuning fuzzy sliding mode mechanism to modify the output scaling factor and adds a dead zone compensator to achieve a constant oil film thickness. Finally, the experimental results are used to verify the feasibility and practical implementation success of this study.

Abstract: The versatile and smart feature of MPC is the ease that it can work with MIMO plants, whereas adaptive PID controller is very difficult to implement and also provides unsatisfactory results unless updated to a rather complex controller by incorporating intelligent algorithms such as Particle Swarm Optimization, Genetic Algorithm and Neural Network. In this paper we present a novel but simple Model Predicative Controller for the Flight Control of Ornithopters. The performance was evaluated for the MISO and MIMO setup for almost all possible cases of various operating conditions resulting not only in faster response but also eliminating overshoot. The results obtained from the use of Model Predictive Controller for the flight control of the Micro Arial Vehicles shows comprehensively that MPC can be used as the future means for the control of these sophisticated and very complex ornithopters.

Abstract: State-dependent Riccati equation (SDRE) based controller design is an emerging trend in real world applications. This paper describes the design of an integrated roll, yaw and pitch attitude controller for a fin stabilized and canard controlled 122mm artillery rocket using SDRE technique. The rocket configuration considered is with front canards and foldable straight tail fins, and is given initial spin at the time of launch. Tails fins are deployed immediately after launch and offer high roll damping moment thereby reducing the spin rate to zero within six seconds of flight. The canards are then deployed and the roll orientation of rocket is regulated to zero with the canard deflection commands generated by the SDRE based roll autopilot. Once the roll orientation of rocket is brought to zero, the full state integrated roll, yaw and pitch autopilot comes into action. Elements of the state weighing matrix for Riccati equation have been chosen to be state dependent to exploit the design flexibility offered by the Riccati equation technique. Simulation results show significant reduction in impact point dispersion with the attitude controlled trajectory as compared to uncontrolled trajectory. Monte Carlo simulations have been performed to prove the efficacy of the proposed controller design even in the presence of wide range of deviations in rocket parameters.

Abstract: Regarding the functional requirements for smart substation in fault recorder, this paper introduced μC / OS-II, an embedded real-time multitasking operating system as the functional design. The program works with the embedded operating system, the state machine theory and new methods for embedded development, whilst tasking full use of the advantages of such functions as task scheduling, message queues, etc., aiming to achieve a fault recorder function of intelligent substation. More than taking care of the difficulty of programming, it could improve the program reliability and portability. The program has been applied in an intelligent substation protection in centralized control unit, which has brought back a good fault recorder performance. On this basis, more functions can be integrated, including network log analysis, state estimation, etc., in order to truly meet the application requirements of the smart substations.