Abstract: When calculating sound intensity by indirectly measuring way, the sound pressures
obtained from two microphones should be mathematically averaged as the sound pressure of
measured point. The research showed that the method exists lower of allowable value in the high
frequency area. Using the geometric average value of two measured points to replace the sound
pressure of measured point, studying the measurement of sound intensity in scattering field, the errors
from which were compared. The result showed that the error of geometric average sound intensity
was more flat than that of mathematic average. So the sound intensity obtained from geometric
average sound pressure is more suitable for the measurement of a wider frequency range. And the
computing time is short, which can raise the measurement efficiency and the real-time of
Abstract: The rotating platform is one of important components of the platform-based lifting picking
vehicle, which guarantees that the vehicle works well in mountainous terrain. Based on a brief
introduction of structural composition and function of rotating platform, the deflection mechanism of
rotating platform was analyzed theoretically. By analyzing the structural composition and calculating
DOF (Degrees of Freedom), the reasonableness of the scheme was verified and the kinematics
equations were established. According to the stability requirements of picking vehicle and the
characteristics of operating environment in mountain, the design theory for the support system of
rotating platform and its performance requirements were discussed, and further the important
structural parameters and design methods was studied.
Abstract: To provide theory and technique support for the research on dynamic properties of flexible
lock-unlock technology, dynamic equation of band is built up based on the muti-body dynamics.
Simulation based on modal neutral file and mixed model with rigid and flexible properties are
accomplished in the software of ADAMS. The result reveals that the later one is much closed to the
Abstract: The patternless casting manufacturing (PCM) technique adopted two nozzles to spray the
binder and the curing agent separately into the dry sand under the control of a computer. In the PCM
technique, the resin content of sand mold is mostly determined the quality of the final casts. In this
paper the content of the binder droplets in sand particles is analyzed in detail. Thus it provides the
theoretical basis for these process parameters such as scanning speed, layer thickness and so on. The
results of experiments well verify the analysis.
Abstract: Product agile customization design is an effective technological measure to win the
customers and improve development efficiency. It needs designer to determine product structure
quickly according to customer’s customized requirements. In this paper, a novel design method of
product agile customization is presented by integrating rough set (RS) theory and artificial neural
network (ANN) in the design process. In the method, design demands are reduced so as to form
effective decision conditions by applying RS, and on that basis ANN models between design
demands of different design stages and corresponding product structures are established so as to
determine product structural styles quickly by applying ANN. Finally, this method is applied to the
general schematic design process of a roll plate machine’s customization, and its validity is verified.
Abstract: A novel 2-TPR/1-SPR spatial 3-DOF parallel mechanism is studied. The studied mechanism is composed of a moving platform connected to a fixed platform by means of three actuated limbs. The two of the three limbs are TPR serial manipulators and the other one is SPR serial manipulator. Each TPR limb consists of a Hoke joint T connecting to the fixed platform, a prismatic pair P, and a revolute pair R connecting to the moving platform. The SPR limb consists of a spherical pair S connecting to the fixed platform, a prismatic pair P, and revolute pair R connecting to the moving platform. Moving character of this mechanism are analyzed by using the theory of screws. The moving platform of this mechanism has one translational DOF, and it is translational moving along the normal direction of the plane which passes through the moving platform. The moving platform of this mechanism also have two rotational DOFs, and they are rotational moving that are rotated the lines which intersect each one of three binding line-vectors of the mechanism at the same time.
Abstract: Airborne particulate matter is known for its environmental impact and is suspected of
causing adverse health effects. Especially the role of ultrafine particles smaller than 0.1μm, which
amongst others are emitted by diesel engines, is the subject of current health related discussions. In
order to solve this problem, many filtration methods have been researched, while so far the results are
unsatisfactory. In this paper, a method of utilizing the carbonized micron wood fiber (CMWF) as the
filter material is presented and a corresponding numerical simulation method is applied. Furthermore,
a kind of detachable DPF is developed, a diesel engine bench test is conducted and the influence
elements upon Δp/H are researched. Theory and test prove that the numerical simulation method can
be consistent with the test very well and the CMWF DPF has not only the low flow resistance and
high efficient filtration but also very suitable for diesel exhaust gas purification.
Abstract: Acording to the fact that the finite element model of electromagnetic vibration shaker for
virtual experiment is not accurate enough to complete accurately spacecraft test, made a correlation
analysis of the finite element output frequency response function and the measured frequency
response function by their correlation coefficients. Analyzed the sensitivity of the materials for FRF
and screened the parameters to update, made the correlation coefficient error of electromagnetic
vibration shaker finite element model frequency response function and the measured as the
optimization objective, the optimization and modification of shaker finite element model parameters
were completed by iteration method. The frequency response function of the modified finite element
model approximately agreed with the experimental frequency response function. It met the virtual
experiments of electromagnetic vibration shaker.
Abstract: In response to the impossibility of directly using data of the actual road show experiment
to the motion simulation of simulators, due to the limited work space of simulators, this paper begins
with an attempt to extract the main frequency components of original signals by spectrum analysis
and allow the input signal to meet performance requirements by adjusting the phase offset
corresponding to the various frequency components. The paper proceeds with the regeneration of the
signals capable of reflecting the motion characteristics of the original data and meeting the
performance requirements of motion simulators by selecting these phase offsets as the design
variables, selecting simulator’s displacement, velocity, and acceleration as the optimization
objectives and applying Genetic Algorithm toolbox of Matlab to develop the optimization model. The
paper ends with the efforts to check mechanism singularity by calculating the Jacobian matrix
condition number of the regenerating signals and thus obtain the regenerating signals compatible with
the work space, capable of fulfilling the performance requirements of motion simulators and free of
continuous region singularity.
Abstract: This paper uses the grey relational analysis to find the optimal values of parameters of the servo drives and the controller of a five-axis CNC tool grinder in order to improve precision of grinding and accuracy of end mills. The experimental planning and design are based on the Taguchi method. There are totally six control factors in the experiments, and each factor has three levels. An L18 orthogonal array was applied for the experiments, and each experiment was repeated three times. The grey relational approach was then employed to find the optimal values to the drives and the controller. These values were utilized for grinding a ball nose end mill of cemented tungsten carbide with two-flute and 6 mm in outside diameter. Finally, a well-known tool measuring and inspection machine was used to measure the geometric parameters of the end mill for the initial design and the optimal design. Experimental results show that the grinding time is reduced up to 6.02 ％, and the precision of the ball nose end mill is also improved. Thus, the results demonstrate the effectiveness of the proposed approach.