Applied Mechanics and Materials Vols. 190-191

Abstract: Propose a new algorithm that use Euler angles to calculate directly large relative position and attitude of rendezvous and docking. By analyzing the feasibility of using Euler angles to solve instead of using quaternion and deriving the relations between the coordinates of the identification-points and the coordinates of point-images, a group of non-linear equations including relative position and attitude is established. It is proved that three non-collinear points are sufficient and required to determine the position and attitude uniquely. The whole deriving process does not mention any assumption and simplification in theory. Simulations indicate that the algorithm is high-accurate, unique-solution and wide application scope.

Abstract: The giant hydraulic die press is our country national defense and the infrastructure essential equipment, the synchronous control system is the essential device to the giant forging hydraulic press, its synchronization control performance quality is good or bad will directly determine the quality of the product. This article through the proof of the theorem, gives the specific steps to achieve H∞ robust control algorithm. The simulation results show that: this control strategy has good inhibition to the change of system parameters, robustness is very strong, can well eliminate the system synchronization error.

Abstract: Abstract. The multi-body dynamics simulation model of the hybrid system with a flexible shaft was established through rationally simplifying the system structure of a parallel hybrid system, assembling the flexible shaft, pulley, piston assembly , rod assembly and the rotor shaft according to the actual constraints, and adding the appropriate connections. The engine cylinder pressure reconstruction model and the motor vector control model were established in MATLAB as system shafting incentives. The simulation analysis of the dynamic characteristics of the system shafting was carried out in the boost mode of the hybrid system. The results show that: the shaft torsional vibration and bending vibration have happened when the hybrid system is running, and the engine cylinder pressure change was the main factor which caused the shaft vibration. Torsional vibration occurs mainly near the even multiple of the frequency of the shaft rotational frequency, and the torsional amplitude decreases gradually with the increase of resonance frequency; radial vibration occurs mainly in the range of 0 to 3 times the rotational frequency.

Abstract: Abstract. The ship side flap valve underwater works with high pressure. In this paper, the valve body is analyzed using seamless connection between the finite element analysis software and Pro/E software. In the analysis, multiple load cases applied to the valve body are as follows: open condition, closed condition and seal test. The analysis result shows the maximum stress value occurs when the flap valve is open. Moreover, stress value is approximately 65 percent the range of the minimum yield strength, but the strength requirement of the valve body is satisfied. Finally, this paper presents a method for weakening the stress concentration effect by increasing the internal transitional fillet radius between the two hollow and intersectant cylinders of the valve body.

Abstract: The giant hydraulic press is the essential equipment of our country national defense and the infrastructure. The hydraulic synchronous control system is the important constituent of the hydraulic press, it is very important in improving the dimension accuracy of the product, ameliorating the force standing state of the die forging hydraulic press frame, extending the life of the die forging hydraulic press body and the moulds. To use 300 MN die forging hydraulic press’s synchronous control system for reference, according to a giant die forging hydraulic press its own characteristics, design the synchronization control system. Through the establishment of the mathematic model of the system, and choose the sliding mode-PID control strategy and simulation, the results show that :using PID sliding-mode control strategy of synchronous control system, the eccentric moment after stability, can over a short period of time after the stagnation, quickly will move back to level calibration beam position, get close to zero static deviation. But using the common sliding mode-PID can not overcome the disturbance bringing by the parameter perturbation, so the corresponding nonlinear and intelligent control strategy is particularly necessary.

Abstract: The methods of the geophysical navigation and acoustic navigation are outlined in this paper. And this paper focuses on the applications of acoustic positioning used on deep tow system. The advantages and disadvantages of three traditional acoustic positioning systems, especially for USBL system, are respectively summarized. Some typical products are listed to illuminate the performance and application of acoustic navigation system. And this paper pointed out the key technical problems to be solved and its development of underwater navigation. Combined acoustic navigation and integrated navigation will become a research hotspot.

Abstract: A lumped parameter model is proposed for analysis of dynamic behavior of a Passive Hydraulic Engine Mount (PHEM) with incorporation of throttle, which is characterized by effective and efficient vibration isolation behavior in the range of both low and high frequencies. The experiments are made for the purpose of PHEM validation. The aim of simulation is to discuss the effect of throttle that the key parts of new mount. It has been shown by comparison of the numerical results with the experimental observations that the present PHEM with throttle achieves good performance for vibration isolation.

Abstract: The ANSYS ICEM was used to build the meshes in the impeller, volute, the sealing rings clearance and the other whole flow field of the flameproof submersible pump with inner motor for coal mine BQW50-70×5-132/N for further simulation, and two outlets were set here and the inner flow character of the pump was simulated. The axial force was numerical analyzed with the changing of the sealing rings gap and the changing of the area of balance hole. Finally, three balance holes, with a total area of 2400mm², 0.2mm sealing rings gap are taken based on this study.

Abstract: In order to suit better for variations of coal and rock with different properties, solve the problem of big fluctuation of a cutting motor power, and ensure the durable high-efficient, high-energetic working of a shearer, a constant power speed-adjusting system of shearer cutting motor is designed based on the theory and the method of single neuron self-adaptive PID controlling, the system effects constant power function of shearer cutting motor by adjusting continually the shearer’s haulage speed. A systematic simulation model is build by using the Matlab/Simulink, and the experiment shows: the speed-adjusting system of single neuron self-adaptive PID controlling has following advantages by comparing it with a traditional controlling method: adjustment time of haulage speed decreases by 0.6s, overshoot and adjustment time of the cutting motor power lower by 2.4% and 0.27s respectively, which improves the working efficiency of the shearer by a rapid reaction speed and a good controlling property.

Abstract: The emulsion pump station is the power source of the hydraulic support and the hydraulic props of fully-mechanized mining face. Providing work medium such as high pressure and big flow for the system used liquid such as hydraulic support are its responsibility. This paper put forward a system can control the pressure of the emulsion pump station based on electro-hydraulic proportional relief valve. After applying the electro-hydraulic proportional relief valve technique, this system reconstructed the pipeline of pump station. In order to realize the control of pressure, this system used the PID controller in PLC technique to perform logical operations and finally controlled the unload action of overflow valve. This paper give a detailed design of the system, and then build a mathematical model based on the electro-hydraulic proportional pressure control system hardware and analysis the results of control using simulation software.