Advanced Materials Research Vol. 1037

Abstract: Aimed at achieving a high speed and precision circumferential positioning of pipe under low energy consumption, a paralleling hydraulic control of variable frequency motor and valve (PHC-VFMV) system is designed for the swing mechanism of segment erector. Firstly, with a view to the working principle of the swing mechanism, a hydraulic circuit of the PHC-VFMV is designed. Then, two sub-circuits of the hydraulic circuit are separately modeled and equipped with suitable controllers. Finally, one valve control (VC) system and the designed PHC-VFMV system are tested in AMEsim platform. Results show that, while guaranteeing a good performance of speed and accuracy, the PHC-VFMV could achieve a better performance in energy saving than VC.

Abstract: This article presents a method for testing and identification of a recovery material of certain missile, systematically analyzes the diagnostic approach and technology of PCB faults, expounds in detail design concept of the system, sets forth the solution using C8051F020 chip as microprocessor and testing of analog and digital I/O with built-in converter, contrives polarity discrimination circuit, provides software design process and main program by means of design thinking of modularized software, which help increasing program reliability and lowering development cost. The experimentation proves that this system is able to precisely position the faulty module of PCB to be identified, as well as make correct and reasonable opinion for maintenance. The design method and concept of this article is of significant value for reference in the research and development of similar testing and identification system.

Abstract: Hydraulic oil temperature with the system condition, environment temperature and heat exchange characteristics, is one of the most significant parameters affecting the performance of hydraulic system. Oil temperature directly changes oil viscosity and leakage characteristics, which affects the damping effect on system performance of hydraulic oil ratio, thereby affects the stability of the hydraulic system and dynamic response. At the same time, it also can cause the seal metamorphism and oil oxidation failure, which causes corrosion and formation of sediments, which affect the normal operation of the system, even brings harm to the equipment. Therefore, improving the working performance and reliability control through the analysis of hydraulic oil temperature is necessary.

Abstract: A network power control system was designed in the paper based on MCU STM32 in order to realize network control to the industrial site power equipment. Software and hardware design scheme of the system were given. STM32F103 chip was used as the main controller in the system and ENC28J60 chip as the Ethernet controller to connect network, the μIP protocol stack was used for network data communication. Network power control test experiment was carried out, the result showed that it can control the equipment power remotely, and can receive real-time information data of the industrial field through Ethernet.Compared with the traditional power control system, this system has the characteristics of intelligence, integration and remote.

Abstract: This paper describes the enhancement of the machining precision of 5-axis machine tools. Most post-processors did not consider the pose errors so that the processing error was increased invisibly. A post processing method with pose error compensation was proposed for table/spindle-tilting type machine tools.12 position errors and 12 rotation errors were compensated by the proposed method. Mathematical model contained pose errors which converted cutter location data into machine motion coordinates was established based on inverse kinematics and the analytical solutions of NC code were derived. The tool paths of the freeform surface machining were posted with the presented method. And the simulation experiment was carried out which verified the feasibility of the post processing method with pose error compensation. Comparison of processing error shows that the post processing with pose error compensation can effectively improve the machining accuracy by approximately 50%.

Abstract: In this paper, the author took an unmanned planting boat as the object of study and conducted a series of roll decay test on condition that the ship model was in different drafts and tilt angle. The author established eight kinds of mathematical model of roll decay motion model system identification by making a cross combination of linear or nonlinear righting moment and linear or nonlinear damping. Based on the principle of system identification, the author established the optimization calculation of the objective function. Then the author adapted the genetic algorithm of system identification program based on Visual Basic 6.0 and got eight kinds of identification programs. By identifying respectively the test data of the roll motion of the unmanned planting boat, the author confirmed the feasibility of the adapted program. Comparing large drafts and tilt angle identification results, the author found a reasonable hydrostatic roll motion equation of the unmanned planing boat in the case of large drafts and tilt angle, and made a preliminary analysis.

Abstract: By presetting correcting device transfer function D(z), this paper puts forward series compensation design approach of minimum beat system. Compared with tradition design method, this way is much simpler and easier.

Abstract: This paper analyzes the principle and advantages of magnetic isolation feedback technology. And an effective method of 5W switching power supply, which can be used for controller of electrically powered wheelchair, is introduced. The main circuit is verified on the DC motor driver module of a wheelchair controller PGDT VR2. The experimental results show that the circuit works stably and can meet the design requirements.

Abstract: This paper presents an implementation of square wave drive on super-high-speed PMSM. In order to solve the problem that the rotor temperature of super-high-speed PMSM rises sharply, this paper compares SVPWM method with square wave method and designs a pre-BUCK PMSM drive. The new drive uses sensorless control algorithm and gets the position signal from BEMF. The simulation and experiment results are shown to exhibit the performance of the drive. The experiments are conducted at speeds up to 50000rpm and the results show that the drive can restrain the rotor temperature from rising remarkably.

Abstract: A hardware-in-the-loop (HWIL) training simulator was developed to avoid high cost and realize intuitionistic teaching in the engine maintenance teaching of a certain type of unmanned aerial vehicle (UAV). The oil free engine HWIL simulator was achieved by the driver-to-the driven switch. According to the needs of teaching , the function of dynamic real-time control in different working areas was implemented by combining dynamic monitoring of the computer with real-time controlling of the single chip microcomputer. The successful development of the simulator improved the teachers’ teaching ability and cadets’operation ability, cut down the training cost and reduced the teaching risk to zero by indoor training of large weapons and equipment.Keywords: engine, simulator, hardware-in-the-loop simulation, teaching