大坡段俯斜开采综放工作面运输机窜动及防倒架管理

为了研究运输机窜动控制及防倒架管理方法,分析、探讨控制运输机窜动的主要原因,结合综放工作面设备结构和采场条件,研究综放工作面运输机上窜下滑控制及架型调整的具体方法。结果表明,除了常用的“伪斜法”辅以“单向推溜法”控制运输机窜动以外,还要做好日常架型的管理,以及介绍架型管理及防倒架的具体方法,对综采工作面运输机上窜下滑、架型管理及防倒架管理具有借鉴意义。

Performance analysis of air suspension system of heavy truck with semi-active fuzzy control

In order to analyze and evaluate the performance of the air suspension system of heavy trucks with semi-active fuzzy control, a three-dimensional nonlinear dynamical model of a typical heavy truck with 16-DOF（degree of freedom） is established based on Matlab/Simulink software. The weighted root-mean-square（RMS） acceleration responses of the vertical driver ＇s seat, the pitch and roll angle of the cab, and the dynamic load coefficient（DLC） are chosen as objective functions, and the air suspension system is optimized and analyzed by the semi-active fuzzy control algorithm when vehicles operate under different operation conditions. The results show that the influence of the roll angle of the cab on the heavy truck ride comfort is clear when vehicles move on the road surface conditions of the ISO level D and ISO level E at a velocity over 27.5 m/s. The weighted RMS acceleration responses of vertical driver＇ s seat, the pitch and roll angle of the cab are decreased by 24%, 30% and 25%, respectively,when vehicles move on the road surface condition of the ISO level B at a velocity of 20 m/s. The value of the DLC also significantly decreases when vehicles operate under different operation conditions. Particularly, the DLC value of the tractor driver axle is greatly reduced by 27.4% when the vehicle operates under a vehicle fully-loaded condition on the road surface condition of ISO level B at a velocity of 27.5 m/s.

Mathematical model of electric hydraulic and powered support control system at a plough mining face

Given the actual working of a fully mechanized plough at a mining face, we have proposed a formula for running constraints between powered supports and a coal plough under assumed geological conditions of the coal face and, on this basis, established an automatic control model of powered supports for the coal plough face. We introduced the working principle of the powered support control system of the plough at the mining face. We established three advanced characteristics of this control system： response speed, reliability and easy maintenance of the system. As well, we briefly introduced, the principal function of primary and subordinate controllers and the realization of the communication system by a Single Bus. Ten controllers were constructed and tested in our laboratorium. The results show that the control model is practical and meets actual conditions. It provides a theoretical basis for designing a comouter control system for a oowered support system of a plough at a mining face.

Vibration Control of Jacket Platforms with Magnetorheological Damper and Experimental Validation~

Magnetorheological （MR） dampers have been proposed to control the vibration of offshore platforms in this paper. The semi-active control strategy based on fuzzy control algorithm was adopted to determine the optimal output control force based on the responses of jacket platforms. A typical jacket platform in Mexico Gulf was selected as the numerical example to investigate the effectiveness of the proposed control method. Furthermore, a model experiment was performed to validate the results of the numerical simulation. The experimental model of the jacket platform was designed based on dynamical similarity criterion by the scale of 1：50. Both of the numerical and experimental results show that the semi-active control system with the MR damper can reduce vibrations of jacket platforms effectively and at the same time the control effect is stable.

An Inverse Problem of Identifying the Radiative Coefficient in a Degenerate Parabolic Equation

The authors investigate an inverse problem of determining the radiative coefficient in a degenerate parabolic equation from the final overspecified data. Being different from other inverse coefficient problems in which the principle coefficients are assumed to be strictly positive definite, the mathematical model discussed in this paper belongs to the second order parabolic equations with non-negative characteristic form, namely, there exists a degeneracy on the lateral boundaries of the domain. Based on the optimal control framework, the problem is transformed into an optimization problem and the existence of the minimizer is established. After the necessary conditions which must be satisfied by the minimizer are deduced, the uniqueness and stability of the minimizer are proved. By minor modification of the cost functional and some a priori regularity conditions imposed on the forward operator, the convergence of the minimizer for the noisy input data is obtained in this paper. The results can be extended to more general degenerate parabolic equations.