Applied Mechanics and Materials Vols. 494-495

Abstract: Oxygen content controller in the closed environment contains two parts, master machine and slave machine, of which the master one in the control room can monitor and control the slave ones hanged on it. The master one can not only read the current value of the salve but also control the parameter values and set the upper and lower limits, and the slave one can set its own limits meanwhile. The slave machines monitor the current oxygen content by 4OX2 oxygen sensor, and convert the content signal into digital signal which is conventional to process by the microcontroller.And then the digital signal will be compared with the limit, if less than the lower limit, the relay will open the valve to release oxygen into the air. On the contrary, if more than the upper threshold, the valve will be closed. In addition, the slave machine also has the calibration function and set its own communication address using DIPswitches. The communication between the master and slave is accomplished by the full duplex RS485 through max489 chip.

Abstract: For the problem that the searching speed of traditional ant colony algorithm in robot path planning problem is slow, this paper will solve this problem with generalized ant colony algorithm. Generalized ant colony algorithm extends the definition of ant colony algorithm and does more general research for ant colony algorithm. Functional update strategy replaces the parametric algorithm update strategy; it accelerates the convergence speed of ant colony algorithm. Applying the generalized ant colony algorithm to robot path planning problem can improve the searching speed of robots and reduce the cost of convergence time.

Abstract: For the problem of inaccuracy of temperature control caused by large inertia, time variability; pure lag in the heating furnace, this article combined the learning mechanism of neural network control with the human thinking and reasoning of fuzzy control, establishing the 3 d fuzzy neural network system. Neural network is used to implement membership function, and drive the fuzzy reasoning. Using neural network, fuzzy modeling, achieve the goal of refinement fuzzy rules. Then I established the temperature control model of heating furnace which based on the fuzzy neural network. After using the model, the control accuracy and the uniformity of the slab temperature has been improved; the temperature difference between head and tail of slab has been reduced; which have a positive impact on the reducing of fuel consumption in the heating furnace, the improvement of yield in production line and the achievement of energy conservation and environmental protection.

Abstract: This paper studies the problem of robust stability of sampling system with long time-delay. In such system, time-delay and norm-bounded variation has been considered, and then, a sufficient condition of robust stability is derived Lyapunov-based method. Finally, feasibility and effectiveness has been shown by a numerical example.

Abstract: Ride height adjustment of air suspension can be achieved by pumping air into or releasing air out of the air spring. However, energy loss would inevitably occur during the two processes,and test system of closed loop air suspension was established.Working process of the system was divided into three procedures as charging, discharging and boosting. Energy loss calculation method-compressed gas available energy was put forward, quantitative analysis of energy consumption during charging and discharging was carried out. Experiment results showed that energy consumption during charging process rises as initial air pressure of high pressure chamber increases, and during discharging and boosting processes, energy consumption decreases when initial air pressure of low pressure chamber increases. Under the same conditions, compared with open-loop air suspension, closed loop air suspension system with high & low pressure chambers can save plenty of energy.

Abstract: PID control is one of the earliest control strategy and till has the most widely use in the industrial process at the present. The PID parameter tuning and optimizing decide what the control performance of the control system can achieve. PID parameter tuning is the core content in control system design. In this paper, aiming at the complexity of PID parameter tuning process, the critical ratio method was optimized and propose a simple and effective method of tuning PID parameters. By simulation, this method turn out to be simple and effective, good real-time performance.

Abstract: Manipulator as a controlled object is often applied in industrial production and processing in the field of automatic control. It can replace worker achieve a variety of work, such as transportation of workpiece material, components assembly, cutting, spraying, etc. This design is based on the object teaching experiment device of manipulator THWJX - 1.

Abstract: In this thesis , the control strategy based on sensorless BLDCM(Brushless DC Motor) has been researched.A control system for BLDCM operating on ADSP-BF548 has been given. we focus on studying the control strategy of sensorless BLDC motor based on back-EMF detection, and present a control system for BLDC motor based on ADSP-BF548 special for motor control. The calculation method of back EMF in BLDC motor was deduced and the hardware circuit of line voltage detecting was designed. A pre-position starting tactics based on back EMF detection and a tactics of phase converting by postponing back-emf-zero-crossing detecting was designed. The signal wave was filtered by postponing back-emf-zero-crossing detecting when back-emf-zero-crossing had been detected. To release the phase delay caused by hardware filtering, a phase compensation algorithm has been designed. The PID adjusting algorithm and other strategy are designed in this program. Experimental results show that the control system has good speed adjusting performance and runs stably.

Abstract: With the development of information technology, computer simulation technology has become a necessary mean for many complex systems analysis, design, testing, evaluation and other work. Time step method to carry on the research is applied in this paper according to the situation of simulation on time process control complex for computer. First, time step method mechanism describes by graphics; Then, we can research on the simulation of process control procedure, including the system's entity scan, all kinds of events scan, entities and events to combine scan; Finally, we can study on the same time step method that usually used on the computer simulation of process control. Content of this study provide technical and methodological support for computer simulation. With the deepening understanding for computer simulation technology, computer simulation of process control based on the time step method is bound to get a wide range of applications.

Abstract: The users and permission management functions of multiple application system will increase management complexity, reduce the convenience of users using.Analyze the module features of application system , LDAP technology , XML and RBAC technologies,etc. to build a permission centralized control system and combine with configuration file to solve the docking problems between various application systems and control systems.The system achieve unified management of users, permissions, application modules and access control and improve management efficiency and user experience.