Applied Mechanics and Materials Vol. 729

Abstract: In the MATLAB/Simulink environment through the simulation analysis, has determined the NFXLMS algorithm of the filter order and the convergence factor control parameters in the vehicle adaptive active noise control system used; adaptive active interior noise control system was constructed in a light bus, the tested vehicle engine was conducted noise cancellation control when its work in 1080rpm and 2400rpm; the results show that, the overall amount of noise reduction of driver's right ear position respectively 9.7dB (Lin) and 8.9dB (Lin).

Abstract: For electric power steering is weak and can not be used in heavy vehicles. In order to solve this problem, according to the characteristic that the driving torque of left and right steering wheel can be independently controlled in electric wheel driving vehicle, a new non-trapezium-steering system has been proposed based on electric wheel driving and powering in this paper. This system makes use of the steering torque around the kingpin from electric wheel driving, and is controlled by steering constraint mechanism. Steering system force analysis was conducted to analyze the feasibility of the system in theory. On this basis, a small prototype vehicle was designed. With the use of Bluetooth wireless serial chip and STC12c5a60s2 microcontrollers, the steering-by-wire system lower computer was developed. With the LabView software, the upper computer system was developed in notebook computer. With these two systems, the steering system can conduct data acquisition and control. To verify the performance of the system, the steering angle step input test while vehicle is stationary, the steering angle step input test at low running speed were carried out respectively on the prototype vehicle. Results of steering wheel turning angle and wheel rotation rate show that non-trapezium steering-by-wire electric wheel driving power system can complete steering operation in a variety of conditions, and after removing steering trapezium, each wheel can be separately controlled for steering, and easy to implement multi-mode steering.

Abstract: This article covers an applied study on the computer-aided engineering analysis of the damage occurring in the disc bearing profiles of a disc harrow used in the agricultural sector and redesigning the existing structure.The damage to the machine had occurred in the form of deformation of the plastic structure in the disk-bearing profiles. In order to examine the damage, to collect information on the stress values causing the damage and to re-arrange the damaged design, system construction was modeled with CATIA and structural stress analysis was performed. Results of finite element stress analysis revealed weak regions of the construction under the variable dynamic loading, and the strength with inadequate and improper distribution was determined. Design goals aiming to improve present design were defined in order to prevent the occurrence of damage, and a design meeting these objectives was obtained. The existing system profiles and links were re-arranged in accordance with this design. Then, an experimental analysis consisting of 250 hours of operation was also performed with these new arrangements. No damage occurrence was observed in the new design, so the validity of the design was confirmed.

Abstract: The farmland weeds directly affect the crops yields, and the intra-row weeds are more difficult to eliminate than inter-row weeds. With the harm of chemical weeding technology cognition by people, the growth of awareness of environmental protection consciousness and food safety, the non-chemical weeding technology get more and more attention. Mechanical weeding as a good alternative method get more attention, and the intra-row intelligent mechanical weeding technology becomes a hot spot of research. The research on intra-row intelligent mechanical weeding technology of China have a large gap compared with developed countries. In this work, the current research of intra-row mechanical weeding technology of developed countries and China was reviewed, and the development trend of intra-row intelligent mechanical weeding technology of China were prospected. The universities and research institutes should be encouraged to learn from foreign advanced technology and the design concept of intelligent weeding equipment, increase the investment in intelligent mechanical weeding technology research and promotion.

Abstract: Cloud computing is a new computing technology and IT service providing method. It development evolved with distributed computing, parallel computing, high-speed network technology. Cloud computing provide robust, high efficiency service capabilities by centralizing management and overall dispatch service resource, and providing services for end users through the consistency of virtual environment have undergone profound changes. It in the service ability of organization and service delivery methods. As the telecommunication enterprise, either from their own business operation system support needs, or from a provider of the high speed network services and integrated information service will benefit from the development of cloud computing.

Abstract: In tunnel lining quality testing and advanced geological forecasting, the main concern is the local signals, such as the position and form of defects or the unusual mutations; while all kinds of filtering methods based on Fourier transformation reflect the overall characteristics of the signals, but can not describe the time-frequency local properties of the signals; however, the characteristics of the multi-resolution based on the wavelet transformation have the ability to show the local characteristics of the signals in terms of the time domain and frequency domain; based on the analysis of multi-wavelet theory, the paper infers the decomposition and reconstruction of CL4 multi-wavelet, discusses the necessity of multi-wavelet preprocessing and conducts the equalization treatment of CL4 multi-wavelet, realizes CL4 balanced multi-wavelet threshold filtering algorithm based on the application of MATLAB language programming, and compares with the traditional filtering effect based on Fourier transformation; the results show that the both conventional filter and CL4 balanced multi-wavelet filter can clearly distinguish the unusual targets; but the target characteristics through multi-wavelet transformation are enhanced; the lineups are clearer, the noises are removed more thoroughly, the signals are reserved more completely and the images become “clearer”. The multi-wavelet transformation provides good assistance for improvement in GPR image resolution and the definition of the target detection image, and achieves better filtering effect.

Abstract: Based on the simple transfer function design, this thesis presents a technology for complicated transfer function design. It converts complicated transfer function design problem into the fusing of several simple transfer function. The keystone is to formulate the transfer function fusing problem into searching for optimal fusing proportion, and to generate the new fusing proportion using a similarity evaluation method, which is based on expectation fitness. To a large extent, it simplifies the design process of complicated transfer function.

Abstract: Some nonlinear wave equations are more difficult to solve analytically. Exponential Time Differencing (ETD) technique requires minimum stages to obtain the required accurateness, which suggests an efficient technique relating to computational duration that ensures remarkable stability characteristics upon resolving the nonlinear wave equations. This article solves the non-diagonal example of Fisher equation via the exponential time differencing Runge-Kutta 4 method (ETDRK4). Implementation of the method is demonstrated by short Matlab programs.

Abstract: We studied the Diophantine equation . By using the elementary method and algebaic number theroy, we obtain the following concusions: (i) Let be an odd number, one necessary condition which the equation has integer solutions is that contains some square factors. (ii) Let be an even number, when , all integer solutions for the equation are; when , all integer solutions are ; when the equation has no integer solution.

Abstract: Method of active thermal action on zone of thermo-conductive inclusions by use of direct heat flow has been discussed.