Applied Mechanics and Materials Vols. 152-154

Abstract: The Vertical Take-off and Landing (VTOL) Maritime Unmanned Aerial Vehicle (MUAV) has a number of applications including surveillance, search & rescue and real-time communications within a maritime environment. The objectives of this work is to study, research, design and develop, up to implantation, methodologies to apply efficient Command, Control, Navigation and Avionics Scenarios for VTOL-UAV robot operations within maritime air environments. The purpose of this paper is to introduce the overall control system of a five-rotor MUAV and the theoretical analysis of the control system. The controller is derived from the Paparazzi system, which is an open source community hardware and software package for all forms of Unmanned Aerial Vehicles (UAVs).

Abstract: The transfer alignment processes of the ship-borne weapon and the shipboard aircraft are limited by ship0s maneuver, for large ship, it is hope that the transfer alignment can be executed just under the circumstances of sea wave without any intentional ship0s maneuver. Attitude plus angular rate matching and velocity plus attitude matching as the two possible methods which can give accurate estimations of misalignments between MINS and SINS just under swaying maneuver are studied in this paper. Simulation results show that under the circumstance of sea waves and parameters of ships dynamic deformation, attitude plus angular rate matching filter can give better estimations of misalignment angles than velocity plus attitude matching filter. In addition, the estimation accuracy of attitude plus angular rate matching filter is barely affected by sea condition.

Abstract: This paper discuses intelligent techniques used to monitor and correct operational abnormalities in Autonomous Underwater Vehicles. Neural Networks are usually utilised in the diagnosis section, while Fuzzy Logic is implemented in the prognosis and remedy sections. The performance of an AUV’s sub-system has a great affect on the overall success of the vehicle. Once a sub-system becomes faulty, the various components associated with the control of the AUV may get influenced, which can degrade the overall performance of the integrated system or make it invalid altogether, [1]. Such failures may result in large amounts of wasted time, loss of data and increases in mission costs.

Abstract: Driving fatigue is one of the main reasons of traffic accident. In this field, the method based on multi-source information fusion has been a leading technique. A driver fatigue recognition model based on the Bayesian network was introduced in this paper. The real-time system monitored the state of the driver's features such as eyes, mouth and head movement through computer vision technique, their results were fused with Bayesian network inference algorithm and the final fusion result could be inferred according to the probability values of different variables states. Test results showed that this method could be more reasonably robust, reliable, and accurate in fatigue detection.

Abstract: In order to increase market competition, high quality of strip production was demanded. So the quality control of strip was strictly and more active by all the major steelmakers. Today, the device objects of flatness control had extended from tandem mill to subsequent continuous annealing line (CAPL), continuous galvanizing line (CGL), color coating line (CCL) and finishing processing lines, and the types of strip defects researches also have extended from continuous longitudinal waves along lengthwise to warping and composite flatness defect of warping and buckling. In this paper, the simulation model of tension leveling has been established. The effect of bending roll, leveling roll intermesh and strip tension to the distribution of elongation in thickness for strip have been given. Base on this, the analysis model of warping defect of on-line and off-line strip have been built by ABAQUS. On the basis of analyzed the mechanism, proposed measures to reduce the value of cross bow. These measures have been applied in production; the effect of application was obvious.

Abstract: According to the experience of traffic accident investigation over the years, the pointer of some crashed vehicles’ speedometer will stay in one place because of collision spread or heavily vibration, which may indicate the vehicle collision speed. However, the correlation between the residual speed value and actual vehicle collision speed still remains to be examined. For the practical needs of traffic accident reconstruction, this research work is carried out. Based on the principles of traditional speedometers, vehicle impact mechanics and failure mechanism, the damage and failure mode of speedometer in collision are studied. Through the statistics of 15 real traffic accident cases, the features and law about the pointer information of damaged speedometers are obtained initially. As an example, one of these cases is analyzed and calculated to verify the assumption. The availability of the mark information on the indicated place of speedometer after accidents (i.e. the correlation between the speed value of pointers and actual vehicle collision speed) is discussed, which can provide effective means and references for accident reconstruction and vehicle speed identification.

Abstract: This paper proposed a method to analyses and obtain the vibration identities of DTG(Dynamically Tuned Gyroscope) within the vibration-overloading environment based on ANSYS11.0. Finite element model of DTG was constructed by ANSYS11.0. The Natural Frequencies and vibration modals of DTG in the cases of both being stationary and rotating were studied respectively through the method of modal analysis. The influence of each-rank vibration model of DTG on its output was investigated. The result of this paper provides a stable basis for improving the design of DTG and enhancing the functions of it.

Abstract: A typical hybrid RANS-LES approach, DES (Detached Eddy Simulation), was introduced into cavitating flow simulation in this paper. The applicability of two DES models, including one equation DES model and SST k-ω DES model, and standard k-ε model was analyzed through experimental data of a water tunnel experiment. Validation results illustrate that the precision of DES method depends on the RANS model used and the length scale used to distinguish LES zone and RANS zone. The SST k-ω DES method can well predict cavitating flow. The averaged results gained through this model are better than those of standard k-ε or one equation DES model. By comparison, the one equation DES model shows little advantage than standard k-ε model to simulate cavitating flow.

Abstract: Traffic–related pollutant has been recognized as an air pollution hot spot due to its large emission rate and great health impacts for the exposed population. In the present investigation, a computational fluid dynamics technique is used to investigate the effect of street layout on pollutant dispersion and find proper location for air inlet in ventilation systems. Four typical configurations of asymmetric street canyons are considered. It is found that pollutant retention time at people stayed zones is shorter, when buildings near the road are laid as down-wind building lower than the up-wind building. For buildings at down-wind side of a main road, air inlet should be located at the leeward façade of the building.

Abstract: One of the key aspects in designing an Autonomous Underwater Vehicle (AUV) simulation framework is sensor modeling. This paper presents specifically the underwater sonar sensor modeling structure used in the proposed AUV simulation framework. This sensor model covers the mathematical aspects from the field of acoustics which mimics real world sensors. Simplified sonar signal models are widely used however rarely discussed in the literature. Based on this designed simulation framework, simple scenario using different sonar configuration is shown and discussed. This paper shows the formulation of a typical side-scan sonar with emphasis on the assumptions which leads to the simplification of the sonar model. The sonar sensor model is built based on a developed AUV test-bed which was done previously in the University of Adelaide.