Applied Mechanics and Materials Vols. 236-237

Abstract: Combining the virtual instrument technology with the fiber Bragg grating sensing technology, a new fiber Bragg grating sensing demodulation system based on Lab VIEW has been designed. The unbalanced Mach-Zehnder interferometer demodulation technology has been used in this system to translate the fiber Bragg grating wavelength signals in which the strain information is contained into the phase signals，and transfer it to the virtual instrument based on Lab VIEW with the high speed data acquisition card，then conduct process operations and results display [1]. At last, the value of measured strain can be obtained. Compared with the conventional demodulations system，the accuracy this interferometer demodulation system’s measurement has been increased greatly. At the same time, it solves the problem of high cost, large volume and only displays the wavelength with the conventional demodulations system.

Abstract: The existing grating type sensors such as optical grating sensor, have long been designed to rely on the precise mechanical space division technology, which is hard to develop without heavy investment. A theoretical concept, time-space coordinate transformation, was presented to realize measuring spatial displacement with time difference. Similar to the principle of circular time grating based on rotating electrical machine, linear time grating is designed based on the principle of linear motor, with which the physical and mathematical models of linear time grating are established. Based on these models linear time grating mechanical structure is designed, which has commercialization value. The resolution of linear time grating can achieve 0.1μm tested by National Institute of Measurement and Testing Technology.

Abstract: According to the composition of the submarine hydraulic rudder system, the paper analyzed the different advantages and disadvantages of the rudder type, steering agencies and the hydraulic rudder control system as well as the scope of application. System steering bodies of pump control servo, variable pump displacement control system, steering control system and rudder hydrodynamic interference model were modeled. Fuzzy logic hydraulic servo parameter adjustment method is presented, and simulation analysis of the variable pump displacement control system and steering system. As the system parameter uncertainties and load disturbance, the performance impact of parameter variation and load disturbance simulation analysis.

Abstract: This paper proposes an ultra-low power design based on C8051F410 which is used in a timer system for industrial production and device detection failure occurred at a time and the record of relevant information. Two aspects like system hardware circuit and software design of the ultra-low power timer system are demonstrated. This system features low power consumption from the entire system, including the Chinese man-machine interface which consumes only 1mA power cost. This system is suitable for the situations where battery power is limited.

Abstract: There is a nonlinear measurement error of the vibration-cylinder air-pressure sensor when the environment temperature changes; To solve the problem, the paper carried out a research on vibration-cylinder air-pressure sensor temperature compensation based on radial basis function(RBF) neural network; The temperature error characteristics of the sensor was studied; The sensor temperature compensation of RBF neural network structures and algorithms was designed; The centers, variances, weights, and the hidden layer neuron number of the radial basis function were determined. The experiments showed that the trained RBF neural network can approximate the input-output relationship of the vibration-cylinder air-pressure sensor in high accuracy.

Abstract: In airborne MIMO radar, distributing characteristic of clutter have some relation with transmitted waveform diversity and Waveform Synthetic Structure. In this paper , we use the predominance of Transmitted waveform diversity on airborne MIMO radar, A joint transmitter-receiver adaptive dispose algorithm is proposed, and STAP dispose is done in wave, air and time dimension for airborne MIMO radar. The result of simulations show the proposed algorithm achieved the aim of clutter joint suppression, sequentially, which increase the performance of clutter suppression on airborne MIMO radar.

Abstract: This paper puts forward a distributed automation scheme with grounding protection for 10kV aerial wire, which is based on the outgoing line and feeder circuit breaker in substation, the intelligent column circuit breaker and the intelligent load switch. Though the outgoing line and feeder circuit breaker in substation, the intelligent column circuit breaker and the load switch cooperating with each other, Which could isolate and exclude the aerial wire transient fault automatically, and isolate the permanent fault immediately. Practical application results show that the application of the scheme have reduced the hours of power failure, reduced maintenance time and improved the stability of the system.

Abstract: A significant source of noise and vibration in high speed machine tool spindle is bearing induced vibration, which is caused by geometrical characteristics and interactions between rolling members with surface irregularities. In this paper, analytical approach was proposed to calculate the bearing internal load distribution of spindle, with consideration of the operating conditions. The influences of operating conditions to internal load distribution, contact angles were analyzed. Furthermore, the estimation of power spectral density (PSD) method was used to analyze determination of bearing frequencies. The bearing preload of machine tool spindle was estimated according to the change of ball bearing frequencies. Experiments were carried out in a spindle bearing test rig to verify the validity of the presented analytical method. The method described in this paper can achieve the estimation for bearing preload of machine tool spindle.

Abstract: Taking the wheel-legged lunar rover based on double-half-revolution mechanism as a research object, this paper has made a dynamics simulation for the simplified virtual prototype model of lunar rover under several typical road conditions, with the purpose of obtaining the mechanical data of the wheel-leg planetary mechanism shafts. On this basis, this paper established the finite element analysis model of the wheel-leg planetary mechanism shafts, and analyzed their stress by using finite element analysis software ANSYS. Based on ANSYS Parametric Design Language (APDL), the optimization design for the above shafts were done combined with the least-square approximation optimization method. The results show that the optimized shafts not only meet the strength requirement, but also their weights are about 30% lower than the original, which will provide a new and effective way for optimizing the whole wheel-leg structure of lunar rover.

Abstract: In many cases, pouring concrete automatically instead of manually will lessen the operator’s labor intensity and increase productivity dramatically. An automatic pouring system was schemed in this paper, as well as the planning of pouring trajectory. A simulation model was built based on virtual prototyping, and the impact of new automatic pouring system on the boom system was verified with the co-simulation method. Since the complexity of the work environment, the obstacle avoidance of boom system was analyzed and planned. A 3D program based on virtual reality technology was built to simulate the automatic pouring process.