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When the combat platform is running on the road at a constant speed, it will have different vibration responses due to the different speed and road roughness. Road excitation is the main vibration source of the vibration system of the combat platform. Obtaining accurate road information is the key to analyze and evaluate the impact of the combat platform system on the road. In this paper, based on the fitting expression of road power spectral density recommended by GB/T7031-2005 and Simulink simulation software, the simulation model of combat platform is established when it is moving, and then the time-domain response of 1/2 combat platform system dynamics model under road random excitation is analyzed. The influence of road roughness and running speed on the vibration response of platform body is analyzed. It provides a theoretical basis for the design and structure optimization of combat platform.

Metal structure workpieces (such as steel plates, aluminum plates, and composite plates, etc.) have some damage and defects during processing and use, so the health detection of metal plate structures is a necessary link in the project. Non-destructive testing technology based on elastic wave is a potential research direction. This method has the advantages of high efficiency, convenience, fastness, non-contact, and online detection when used to detect defects of metal components. In order to excite the elastic wave in the metal plate structure, this paper researchs and designs a super magnetostriction vibration source based on the magnetostriction effect. The goal of this paper is to manufacture an economical, convenient and excellent performance magnetostriction vibration source, so it’s signifanctant to carry out structural design, optimization and performance testing of the vibration source. Finally, experiments verify that the designed super magnetostriction vibration source can excite elastic waves in the metal plate structure.

Different researches have been conducted in order to make the interpretation of tissues belonging to different individuals carrying different characteristics. These investigations are generally based on vibration signals. In the studies in the literature, the vibration signals that usually appear in the vocal cords during speech are examined. However, there is no study on vibration signals recorded by applying any vibration source. The investigation of the frequency characteristics of the vibration source which has a fixed frequency on the tissues is of great importance both for the information about the tissue and the investigation of the related diseases. In this study, it is aimed to design the user interface to measure the vibration signals taken from certain distances to the vibration source applying vibration at a constant frequency to the living tissues determined on the human face and to analyze these vibration signals. The first part of the equipment consists of a motor and a drive part that provides vibration. Another part consists of accelerometer sensors and drives in MEMs structure which enable the detection of vibrations at certain points of the face region. The control of the hardware is carried out with a microcontroller-based module. With the help of this designed device, it is thought that vibration signals from living tissues can help soft and hardness interpretation of related tissues and body conductivity interpretation of related tissues can be done in future studies.

In this study we propose a novel method for drone surveillance that can simultaneously analyze time-frequency responses in all pixels of a high-frame-rate video. The propellers of flying drones rotate at hundreds of Hz and their principal vibration frequency components are much higher than those of their background objects. To separate the pixels around a drone's propellers from its background, we utilize these time-series features for vibration source localization with pixel-level short-time Fourier transform (STFT). We verify the relationship between the number of taps in the STFT computation and the performance of our algorithm, including the execution time and the localization accuracy, by conducting experiments under various conditions, such as degraded appearance, weather, and defocused blur. The robustness of the proposed algorithm is also verified by localizing a flying multi-copter in real-time in an outdoor scenario.

In this paper, an improved model is designed through optimization process to reduce the radial magnetic force(RMF) which is a vibration source. At this time, radial magnetic force is calculated by the magnetic flux component in the radial direction. This causes the vibration of the motor by applying a force to the stator side. It predicts whether the vibration of motor will be reduced through electromagnetic analysis and structural analysis. And the analysis results are verified by the vibration experiment.

This study proposes a concept of vision-based vibration source localization that can extract objects vibrating at hundreds of Hz with pixel-level accuracy using images captured at an undersampled frame rate that is much lower than the vibration frequency. We discuss how to determine the minimum frame rate of undersampled images so that different vibration frequencies, including DC background components, are separable when the vibration frequencies are larger than the Nyquist frame rate of the images. By executing short-time Fourier transforms for brightness signals at all pixels, we demonstrate the performance of vibration source localization using undersampled images when observing flying multicopters with propellers rotating at hundreds of Hz.

This paper focuses on the experimental vibration analysis of the small-scale unmanned helicopter and the methods to weaken the influence for control design. The vibration source of the small-scale helicopter and the evaluation criteria are introduced. The influence of the main blades dynamic balance on vibration is analyzed and the way to decrease is presented; based on frequency domain analysis technology, the influence of the main rotor speed is well-analyzed and the method to optimize the rotor speed is proposed. The experimental results show that the analysis and the methods are effective and suitable for vibration reduction.

The existing blind source separation algorithm has two problems for the separation of the vibration signal of the transformer. One is the uncertain number of the transformer vibration source. The other is the vibration measuring point, which is not sure after the signal separation. Aiming at these problems, this paper apply the Wavelet-SVD-Clustering analysis method on determinating the number of sources by using one single sensor acquisition of transformer tank vibration signal. The effectiveness of the method is verified by simulation and experimental data analysis. The method of this paper provides guarantee for the correct analysis and separation of the transformer vibration signal.

Near field authentication is of great importance for a range of applications, and has attracted many research efforts in the past decades. Several approaches have been developed and demonstrated their feasibility. The state-of-art works, however, still have much room to improve their automation and usability. First, user assistance is required in most existing approaches, which will be easily observed and imitated by attackers. Second, the authentications of several works heavily depend on special hardware, e.g., Server or high resolution screen, which greatly restricts their application scenarios. In this paper, we present a near field authentication system Tooth that needs little human assistance and is compatible with most smart phones. ToAuth is based on the key insight that the acceleration traces are similar for a pair of smart phones when they are contacting physically and vibrating. The random vibration patterns are sufficiently uncertain to provide high entropy to generate a pair of cryptographic keys yet are inimitable for a third party who does not get in touch with the vibration source. ToAuth leverages the keys to make authentication for smart phones. We implement ToAuth on Android platform and evaluate its performance under various scenarios. Extensive experiments demonstrate ToAuth could achieve around 90% success rate in stable environment, and prevent attacks depended on vibration noise.

Studies have shown that applying a vibration of certain frequencies and intensities on the tooth can accelerate tooth movement, thus shorten orthodontic treatment duration. The optimal frequency may be related to the natural frequency of the tooth-periodontal ligament(PDL)-bone complex (TPBC), therefore we designed a vibrating device which can measure the natural frequency of the TPBC, and produce vibration load with customized frequencies and intensities. This device consists of four parts, vibration source, vibration frequency modulator, vibration amplitude modulator, natural frequency measurement module. To optimize the vibrator's design, specifically structure and natural frequency, static analysis and modal analysis were both made. The application method of the vibrator is also introduced. The designed vibrator can customize vibration load and obtain the natural frequency of TPBC, and it will be used for experiments to obtain the relation between the optimal frequency and the natural frequency of TPBC.

As an important part of flood discharge building, the discharge safety of guide wall is concerned because of its thin shape and long time flood discharge excitation. Due to the lack of full understanding of fluctuating loads, many domestic and international damage accidents of guide wall have happened during the flood discharge. Taking flood discharge loads as excitation, this paper carries out the prototype dynamic test of three gorges left guide wall and analyzes the regularities of distribution of the root-mean-square of dynamic displacement response on the guide wall in the length direction, gives the main vibration source of guide wall and the main results of numerical simulation, prototype vibration displacement and dynamic stress. At last, based on these results, the guide wall flood discharge safety assessment and feedback analysis are carried out.

We designed a new type of multi-point piezoelectric vibrating feeding device and did some research on the transport properties of the two-symmetric-point vibration source devices. Meanwhile, we also analyzed all the factors influencing the velocity of the material-supplying device and indentified the working frequency and voltage, the basic linear relationship between voltage, installation angle-α and the device material-supplying velocity. The phase difference and anchor location can obviously influenced the material-supplying velocity. It worked well when used to deliver some materials with moderate fluidity, such as rice, washing powder, radix isatidis granules, thin salt and so on.

On the basis of reasonably simplifying the structure of disc cutter, the rolling force is used as the vibration source and based on equivalent stiffness method, the method to establish a general vibration differential equation of rolling rock in the rolling direction is further discussed. Through theoretical derivation, a conclusion can be drawn that the range of the vibration frequency is ωf-1.414ωf. Finally, taking an experimental disc cutter rolling concrete as the example, under the certain cutting condition, the vibration model is established and then the vibration frequency is calculated which is approximate equal to 17, 000HZ, so as to lay a theoretical foundation for further analyzing the dynamic performance of the cutter in rock-breaking process.

The safe working of high building is the important content of public safety. With time, the modern high building becomes more and more complex, and the inside electromechanical devices usually bring the abnormal vibration in building system. To ensure the safe working of building and the inside equipments, to discover and eliminate the hidden trouble in time, this paper researches on the real-time distinguishing technology of abnormal vibration source in high building based on time series analysis.

We present in this paper our different steps to develop an efficient integrated mechanical vibration energy harvesting system. We start with a macroscopic structure having a 100 g of moving mass to demonstrate the feasibility of a fully functional electrostatic transduction. An available output power of 16 muW per gram of mobile mass and per Hz over a large frequency band (20-100 Hz) has been obtained with a global efficiency of 60 %. A relative displacement close to the gap value increases the efficiency. To approach that, we introduce a non-linearity in the beams used as springs and guidance with the property to be very flexible for low displacements in order to amplify them and to be very hard for high displacements in order to reduce them. We developed a 10 g structure to validate it. Finally we present the design of an integrated structure able to multiply and maximize the capacitance variation independently of the vibration source. To finish, we present our concept in term of power management.

Rock bolt is one of the most important methods in rock engineering for ground stabilization and the anchorage quality is of the most concern in the field. The characterization of bolts is always evaluated by pullout or torque wrench test which are destructive or inaccurate. It is proposed that some nondestructive methods for testing rock bolt anchors has been preliminary tested in the laboratory and in the field. The research outlined in this paper is aimed at using ultrasonic wave to assess rock bolts performance at underground powerhouse in Baise water conservancy project with giant magnetostrictive vibration source, including anchorage length, anchorage force, anchorage strength and anchorage capacity, and analyze major defects in grout. The method and information would intended to show us the direction of future research in non-destructive rock bolt testing and help us enhance security of rock bolt at underground powerhouse or in tunnel.

To ensure safety of railway operation, it is important to regularly check railway conditions such as deformation of the rails. To monitor rail deformation, this paper presents a method for detecting sources of vibrations of a running train on-line by measuring accelerations, which include the train bogie's lateral acceleration, and the crossbeam's lateral and vertical accelerations. A series of detection algorithms including peak-peak value entropy comparison, weighted correlation coefficients comparison etc. are proposed in the method, according to different characters of vibrations from the train itself and rail deformation. To eliminate the vibration due to the train itself, the algorithm employs the peak-peak value entropy comparison. To identify the order of the vibrations between crossbeam and bogie, a weighted correlation coefficient is applied. Weight center and maximum position are also used for the detection. The algorithms were implemented on a passenger train using ARM processor and real experiments were conducted on the train on the railway between Shenyang and Dalian in China. The experiments demonstrated that the proposed method can produce satisfactory results

ICA (Independent Component Analysis) are used to the fault diagnosis of rotating system. The architecture of diagnosis system based on denoising and blind source separation is proposed. SVM (Support Vector Machine) network is adopted for fault study training and recognition. Using the signal preprocessed by ICA based different contrast function in denosing and blind source separation, the constraint knowledge newly can be easily added to the diagnosis system. The vibration source signal is got by ICA with constraints, and the kernel function of SVM is radical base function (RBF). Simulation results show that the method in this paper has good performance.

The driving simulator used by KMRREC (Kessler Medical Rehabilitation Research and Education Corporation) to test the cognitive driving ability of traumatic brain injury and stroke victims lacked realism. This manuscript summarizes the results and conclusions drawn from a design and construction project. This project has been realized to verify the hypothesis that adding a simulated road vibration source will increase the subject's sense of presence. The finished construction consists of a vibratory platform on which the subject is seated -either in a chair or in a wheelchair- which has four electromagnetic vibrators and four spring loaded feet affixed to it. This project is enabling researchers to ascertain to what level the subject's immersion or "sense of presence" into the simulation may be increased by this sort of system.

The development of an experimental procedure to examine the relationship between vibration exposure and vascular permeability in rats is described. Evans blue dye is used as the permeability marker. The effects of vibration at 125 Hz, 5 g (50 m/s/sup 2/)/spl middot/rms are studied in the gastrocnemius muscle and the liver in order to examine the response of the tissue close to the vibration source and to examine a systemic response, respectively.