Advanced Materials Research Vols. 468-471

Abstract: A numerical simulation study of the hydrodynamics of an oxidation ditch is presented. The numerical method is based on a pressure-correction algorithm of the SIMPLE-type. A multigrid technique based on the full approximation storage (FAS) scheme is employed to accelerate the numerical convergence, while as a turbulence model the RNG κ-ε model with wall functions is used. The numerical results for velocity in the oxidation ditch are obtained．

Abstract: In order to supply reference inputs for the robot system, a high-order polynomial function is proposed according to particular strategies to plan trajectory in joint space, which could provide continuous velocity, acceleration and jerk to ensure safety for electric actuators and stability of the robot during the motion process. The general regression neural network (GRNN) is constructed to realize the proposed polynomial function for its powerful non-linear mapping ability. Parameters of the spreading factor and number of training samples which influence the performances of the network are detailed analyzed. Simulation results show that GRNN has advantages of favorable stability and high precision of function approaching even with few samples. Finally, the trajectory planner based on GRNN is successfully applied for an articulated picking robot to realize the real-time control.

Abstract: Analysis for the road traffic accident is the dissemination of summary analysis of road traffic accidents, all types of traffic into the causes and recommends a system can reduce the effective theory of road traffic accidents. Road traffic system is a person, motor vehicles, the combined effect of the environment from the system. Road traffic safety depends on people, vehicles, roads, environment and road traffic management in all aspects of an integrated system for co-ordination. Characteristics for the occurrence of traffic accidents, road traffic accident on an analysis and research of the impact-spread of road traffic accident, to investigate the microscopic properties of a traffic accident on the traffic flow, emissions, noise impact and the dissemination of the law, analyzing the past, the scene of the accident the speed of other vehicles and drivers of the physical distribution psychological reaction to speed up the disposal of road traffic accidents, to reduce road traffic accidents on traffic flow and avoid the second derivative disasters, the elimination of road accident black spots, build a smart urban road traffic command system, to reduce pollutants in automobile exhaust emissions to protect the natural ecological environment, thus contributing to building a harmonious ecological city transport network.

Abstract: For the low illumination and low contrast in the coal mine, images captured from the video monitor system sometimes are not so clear to help the related personal monitoring the production and safety of the mine. According to the special environment of coal mine, an image enhancement method was presented. In this method the impulse noise which is the mainly noise in the coal mine was first reduced with median filtering, then the low contrast and illumination was greatly improved with the improved adaptive histogram equalization. Experiments show that this method can improve the quality of images underground effectively.

Abstract: Based on the status quo of safety evaluation in China, the paper points out the issues which occur in China's safety evaluation by studying safety evaluation reports and the research results of safety evaluation institutions, and then carries out an analysis of reasons for these issues. This paper proposes that China should strengthen supervision on safety evaluation, improve the employment standards of professional safety evaluators, optimize the market environment of safety evaluation, strengthen education on professional safety evaluators and set up a special training course for professional safety evaluators in an effort to enhance the professional quality and sense of responsibility of professional safety evaluators and to improve the level of safety evaluation in China both internally and externally.

Abstract: A novel method for measurement of vehicle queue length is presented in this paper. Previous methods proposed by researchers for queue detection are based on video sequences. The method proposed here measures the queue length in signal-frame image acquired by a stationary camera, which avoids the effect of uncontrollable camera motions. Besides, considering the varying illumination, double-threshold method is used for image segmentation and flashlight is applied to the system for realizing the round-the-clock traffic status detect. The experiment results of queue length measure from images of real road scenes show the accuracy and reliability of the proposed method.

Abstract: A rapid and sensitive cataluminescence (CTL)-based gas sensor using nanosized Cr₄TiO₈ as a probe was proposed for direct determination of acetone in air. Trace acetone was firstly absorbed on active carbon at room temperature to concentrate, then desorbed at 84°C to determine. The sensor showed high selectivity to acetone at wavelength of 430nm, satisfying activity at temperature of 366°C and good stability at carrier flow rate of 115 ml/min. The linear range of CTL intensity versus concentration of acetone was 2.5~150 mg/m³, and the detection limit (3σ) was 1.2 mg/m³. The recovery of artificial sample was 94.1%—106.2% by this method. The response to formaldehyde and ethanol was insignificant, and there was no response to SO₂, CO and benzene.

Abstract: In order to detect the take-off forces of athletes in long jump, a novel force sensor based take-off board is designed. The take-off board consists of a standard take-off board, two novel force sensors, two support plates and a base. The working mechanism of the strain beam in the force sensor is analyzed and the finite element method(FEM) is used to investigate the structural deformation and stress distribution. Then the sensor is tested. The calibration experimental results demonstrate that the sensor has an excellent measurement linearity (0.6%) and can meet the requirements of practical applications. Then the multi-function take-off board based on the force sensors is designed and manufactured which can make the daily long jump training more scientific.

Abstract: Base on the structure of the mechanical rotary encoder, the characteristics of the glitches and the effective waveform are analyzed. A new algorithm for removing the glitches and accurately counting is introduced. The core idea of the algorithm is to check the output of the phase-lag part when the output of the phase-advance port changes. This algorithm can accurately remove the glitches form the signal and count exactly. This method for glitches removing is very convenient, without additional cost and efficient for rapid rotation.

Abstract: The steering engine is a import execute component in controlling of humanoid robot、manipulator and model aircraft . In this paper, with the single chip processor STC89C52 as the core, and adopting the timer interrupt through serial communication way of real-time control system to produce PWM waves. This method has low cost and simple hardware design, can achieve more independent PWM waveforms output.