Advanced Materials Research Vol. 462

Abstract: Ammunition fuse shell is carried rapidly by the carrying manipulator from heating furnace to molding machine, so manipulator need accurate repeated position. The servo position control system is established to meet manipulator multi-point and flexible location based on pneumatic driving system. Linear mathematical model of the servo position control system is built based proper assumption, and model was used to analyze control system theoretically. The carrying manipulator can satisfy demands including decided order and positions; the control character is good by debugging.

Abstract: The features and working principle of single-wire digital temperature sensor DS18B20 are introduced. Through applying single chip microcontroller AT89C51, the water bath temperature control system is designed based on DS18B20. The paper also gives the structure of the hardware device, main design of software and the C51 program of DS18B20. In the end, the experimental result shows that the DS18B20 system has a higher accuracy.

Abstract: This paper describes a method of indirect rotor position measuring for sensorless SRM. The principle is based on measuring the mutually induced voltage in the two inactive phase which is adjacent to the energized phase of the SRM. The mutual voltage in the inactive phase, induced due to the current in the active phase, varies with the position of the rotor. In this paper the SRM was seen as a Differential transformer. One phase was chosen as the primary coil of the transformer, and the adjacent two phases were the Secondary coils. The two Secondary coils were connected in anti-series. A sine wave signal was poured to the primary coil and then we measured the mutual-inductance voltage and processed in a microcontroller to estimate the position of the rotor. The feasibility of the method was proved by an experiment of 8/6 pole four-phase switched reluctance motor.

Abstract: To solve the problems derived from isolation of application security mechanism and operation system security mechanism, firstly we propose the concept of trusted pipe, which can be used to achieve a uniform security mechanism, and then formally describe the information flow control method in the Communicating Sequential Processes（CSP）. Finally we prove that the model fits a standard definition of non-interference.

Abstract: This paper describes the use of HuaJing Company Pspice Transistor Division developed a miniature accelerometer parameters and signal processing integrated circuits. This system can be on the surface micromachining process for the production of the sensor signal processing, to achieve monolithic integration, but also the fabrication of bulk silicon sensors for signal processing, and hybrid integration.

Abstract: Taking a 315kW, 6kV permanent magnet synchronous motor (PMSM) with solid rotor as an example, the physical and mathematical models of PMSM three dimensional temperature fields analysis are established according to the heat transfer principles. The basic hypothesis and boundary value problems of the solving region in the motor are also presented. The 3-D temperature field in stator of PMSM was calculated, and the influences of heat transfer coefficients with consideration of the axial wind or not on stator temperature were analyzed. By comparing the test results with the calculated results, the influences of axial wind on motor temperature were investigated. These conclusions provide a reference for thermal design of the motor with co-axial fan and enclosure cooling fan.

Abstract: In an uncertain environment intelligent robots can get the direction of the object and calculate the best path to the object based on the collected environment information or the navigation information given by the object. Global path planning is the key technology to achieve autonomous navigation. The design system which described in this paper uses multiple ultrasonic information fusion to detect environmental information around the vehicle system, employs ARM7 embedded processor as the system core to processes the above collected information to realizes obstacle avoidance capabilities. Through ZigBee wireless control module, PC can achieve the navigation control to the vehicle. In the process of the global path planning, the ant colony algorithm is the key of the system, then improve it based on the idea of artificial potential field algorithm and avoid local optimal solution. Test results proved the feasibility and rationality of the system design.

Abstract: It is very difficult to obtain perfect performance to apply the conventional PID (Proportional-Integral-Derivative) controller, because hydraulic headbox needs high precision total pressure control. Transfer function of total pressure control system was identified by using the direct identification method which is based on the least square method for the first-order plus delay time model. Then combined with IMC (Internal-Model-control) –PID method, an IMC-PID controller was designed, which is simple and only needed to adjust one parameter-the time constant of low pass filter. Acceptable performance can also be obtained by tuning time constant of the low pass filter when the model doesn't match with the real process. The algorithm was applied to total pressure control system of hydraulic headbox. Simulation and practical application show that, IMC-PID is of strong robustness and good dynamic characteristics. Finally, the control system is implemented by S7-300 PLC.

Abstract: For the disadvantage of the induction motor direct torque control system’s performance when it runs in a low velocity, the full order flux observer is used to achieve the stator flux observation, and the flux observer precision and the convergence rate depend on proper allocation of the observer poles. Based on the analysis of two full order flux observer pole placement methods,a single degree of freedom pole placement method is proposed, analyzed and discussed. This method can assign the configuration parameters of the observer gain matrix effectively. The simulation results show that the new pole assignment method can effectively inhibit the motor parameter variations and motor rotational velocity impacts the observer gain matrix’s parameters, so it can improve the flux observer and the observed convergence rate precision.

Abstract: In this paper, a design method of a LCM101 liquid crystal display interface circuit is presented. The LCM101 module is a multifunctional and universal type device. It can connect with any MCU or IC interface. So, it is widely used in digital products. The design is implemented by using Verilog HD language. It has been verified on Xilinx Virtex V verification platform and can operate properly. It is a reliable and less resource utilization design. Besides, a new element, which can satisfy the delay time is given in the design. Operation principle, design method and simulation wave will be provided in the body of the paper.