Applied Mechanics and Materials Vol. 711

Abstract: As a new type of vertical take-off and landing unmanned aerial vehicles, four-rotor unmanned aircraft has strong load capacity, simple structure, flexible operation Characteristics, so it is the preferred method of execution the air, and is widely used in military and civil field. Based on four-rotor aircraft structure and movement theory, this paper designs the aircaft control system based on ARM. Based on upper machine, the design of PID control algorithm was tested in this paper. From the results, the stability of the controller is good, and its speed control is superior to the single closed-loop.

Abstract: The main research direction of Numerical control lathe cutting force signal on-line monitoring is to process real-time monitoring, using the sensor, charge amplifier, video acquisition card and computer to collect data and signal. Signal acquisition makes use of the piezoelectric sensor signals and send them to the computer in order to acquire the real-time data and display the dynamic signal so that monitor the process. Signal processing is the course that data will be collected for subsequent processing and analyzing. It includes display, filtering, correlation analysis, spectral analysis, etc. We can conclude the signal’s characteristics after the time domain and frequency domain analysis of signals.

Abstract: The author has designed a visual workbench to realize that the rim can rotate with the workbench. Meanwhile, the linear CCD camera records the rim’s circumference. The paper has explored the measurement method of getting the rim valve hole position using machine vision. The system can calculate the position of rim-hole and control the servo motor by image processing, characteristic recognizing and measuring to locate the position of wheel-hole automatically. And the paper has verified the accuracy of the method by experiments.

Abstract: To improve the navigation precision and reliability of autonomous underwater vehicles, a terrain-aided strapdown inertial navigation based on Federated Filter (FF) is proposed in this paper. The characteristics of strapdown inertial navigation system and terrain-aided navigation system are described in this paper, and Federated Filtering method is applied to the information fusion. Simulation experiments of novel integrated navigation system proposed in the paper were carried out comparing to the traditional Kalman filtering methods. The experiment results suggest that the Federated Filtering method is able to improve the long-time navigation precision and reliability, relative to the traditional Kalman Filtering method.

Abstract: The paper aims at pressure compensation control of bus air brake system in under-pressure state, based on SAE J1939 protocol, using CAN bus technology, the nodes such as vehicle status data acquisition node, brake system pressure information collection node, brake pressure compensation controller node, brake actuator system node, test and diagnostic node were defined, hardware and software of communication interface were designed, under-pressure compensation control network of bus air brake system was built and test, the test results show reliability, stability, real-time of the network meet the requirements of brake control.

Abstract: The article deals with a description of methodology of video analysis of conflict situations, which is used for monitoring and evaluation of road users’ behaviour with usage of video. This methodology is taking e.g. for safety inspections on roads in Czech Republic. In this article, there are also presented results of analysis of conflict situations at concrete cross intersection with cranked priority.

Abstract: Engineering science is bridge of fundamental science and engineering. This paper introduces origin, growth and figuration of engineering science by examining its history, and defines it as science-based engineering theory, or science-abstracted engineering theory by comparing concepts related. Finally, roles, which engineering science play for a nation, are discussed including increasing productivity, providing solutions for national security, and advancing science and technology. The authors suggest more recognition of fundamental science, talent cultivation from Chinese perspective.

Abstract: Cableway bridge is a type of suspension bridge which mainly depends on the cable to suffer the force. The method of calculation unstressed length by parabolic method is introduced in this paper, and the form finding analysis of main cable is also analyzed, thus the method of calculation vector height of middle cross and cable force is concluded. Finally, the relationship between vector height and cable force is fitted based on the practical engineering, bedsides, the error is analyzed between design value and measured value, which comes to the conclusion that measured value is good agreement with design value.

Abstract: A new slip field of slope method based on finite element mesh generated by abaqus is introduced. In this method the weight of soil mass beyond the slip surface is calculated by summing the weight of every finite element mesh beyond the slip surface, which are generated by abaqus software. Similarly, the sliding resistance force on the slip surface is calculated by summing the resistance force of every finite element mesh on the slip surface, which are generated by abaqus software. By this way, the difficult work to identify whether a soil mass is beyond or on the slip surface in traditional slip field method is changed to simple adding operation in this new method. Thus, the new slip field of slope method can be used to analyze the complex geological slope.

Abstract: The article presents the influence of the addition of microsilica, finely divided sodium bentonite and air-entraining admixture for concrete frost-resistance and characteristics of examined concrete pores. Examination of frost-resistance was conducted for 150 cycles of freezing and thawing. For selected series of concrete the examination of the porosity structure of concrete composites was conducted with the use of a device for automatic image analysis and computer program Lucia Concrete. What is more, there was made a designation of: consistency of concrete mix, air content in concrete mix, compression strength, water penetration depth and concrete absorbability.