Applied Mechanics and Materials Vol. 577

Abstract: This article is mainly talking about a pressure control system designed for single screw extruder. In order to achieve constant pressure control of the head, we used fuzzy PID self-tuning techniques and Smith Predictor to control extrusion system and then we used Matlab Simulink toolbox to simulated control result. Simulation results show that the method achieve good control effect and meet the design requirements.

Abstract: To realize the autonomous driving of a certain tracked vehicle, the paper has a research on its steering and braking control technology. According to the steering and braking device’s structure and work principle on the original vehicle, the paper design an electronic pneumatic steering and braking control system before analyzing the design request of the system and introduce the system’s work principle. Applying this system to the original vehicle’s autonomous transformation, a test was conducted on the vehicle, the test prove that the electronic pneumatic steering and braking control system can well satisfied the tracked vehicles’ request of steering and braking.

Abstract: Compared with vector control, direct torque control (DTC) spurned coupling idea and canceled circumgyration coordinates transform. By detecting motor’s stator voltage and current, along with calculating motor’s flux and torque in virtue of the instantaneous space vector theory, DTC controlled flux and torque directly according to the difference between the detecting value and design value. DTC also reduced calculation amount and overcomed the flaw that the system was disturbed by motor’s parameters easily, which were the problems in the vector control. On the basis approach mentioned above, this paper realized the system simulation using DTC. Simulation shows that asynchronous motor control has favorable ability of speed adjusting, short startup time, excellent stability.

Abstract: The double-fed control strategy for AC hoist motor is discussed in this paper. The AC/DC/AC power converter is adopted as main circuit. Three-phase neutral-point-clamped three-level rectifier is used as AC/DC link to realize unity power factor at grid-side, which reduces harmonic distortions. For the DC/AC inverter, three-level topology is used, which is controlled by stator-flux oriented vector control method. Meanwhile, energy flows in bidirectional way by back to back three-level power converter. The hoist motor control system obtains a high dynamic performance when stator side operating in unity power factor condition. The reliability and safety of hoist system is improved based on double PLC. The control system mentioned in this paper is being used to control a shaft hoist with a capacity of 260kW, and the power saving is remarkable.

Abstract: The air-fuel ratio (AFR) control becomes an important research direction in gas engine. This article conducts air-fuel ratio (AFR) closed loop control research in a CNG engine. The injection pulse width of gas is controlled by a controller, oxygen sensor signal as a feedback signal. In order to make the engine can achieve the anticipated air-fuel ratio under different conditions; we adopt fuzzy self-tuning PID control strategy based on feed forward control. We transformed a 2135G diesel engine into the single fuel gas engine. Experimental investigation on the effect of air-fuel ratio closed loop control .Experimental results shows that, fuzzy self-tuning PID control strategy can control CNG engine air-fuel ratio working in the good condition.

Abstract: This paper, based on the EDA software platform and VHDL description method, introduces how to use the FPGA chip to control the multiphase stepper motor. This design, through automatic logic compilation optimization and simulation test and compile, finally completed the function of the stepping motor subdivision drive controller. By testing, it can achieve controlling positive &negative and subdivision for stepper angle.

Abstract: This article presents use the BP neural network to do the attitude angle Information fusion for the Attitude and Heading Reference System (AHRS). In addition, use the more mature BP neural network in a different Area. The algorithm has been applied to the attitude control of a small UAV.

Abstract: This paper focuses on the fuzzy obstacle avoidance algorithm, which is based on the information in dynamic environment with high real-time performance and adaptability. The algorithm can convert the information acquired in three directions through the ultrasonic sensors into fuzzy variables and input into the fuzzy controller, and realize the robot obstacle avoidance according to the inference rules. In order to solve the calculation problem of fuzzy inference rules, a fuzzy inference algorithm based on the addressing is presented to save computing time.

Abstract: This article is the windward electricity supplementary actuation desalination control system conducts the research, With the wind directly driven desalination high pressure pump, Complemented by electricity network as a supplementary, When the wind is great, Also may the back coupling electrical network, This system according to the amount of water desalination successively calculated, design, Select vertical-axis wind turbine impeller, the transmission system, desalination system and control system, final Assembly and test.

Abstract: Based on pneumatic artificial muscle actuator (PMA) technology, a power assist device for the elbow joint actuated by a pair of antagonist muscles was designed. Dynamic models of the power assist device were established, driving characteristics of the device were simulated. The results show that the PMA complies with the requirements of the device, and the device can compensate the resistance caused by the spacesuit and the inertia forces by motion. Hence the device will be a great help for astronauts EVA operation. The research is used as a foundation for future development of power assist spacesuit.