• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.6 s.237
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• pp.889-894
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• 2005

A modeling method for the modal analysis of cantilever plates undergoing in-plane translational acceleration is presented in this paper. Cartesian deformation variables are employed to derive the equations of motion and the resulting equations are transformed into dimensionless forms. To obtain the modal equation from the equations of motion, the in-plane equilibrium strain measures are substituted into the strain energy expression based on Von Karman strain measures. The effects of two dimensionless parameters (related to acceleration and aspect ratio) on the modal characteristics of accelerated plates are investigated through numerical studies.

• Journal of Mechanical Science and Technology
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• v.14 no.7
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• pp.764-772
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• 2000

In this paper, an engine-CVT integrated control algorithm is suggested by considering the inertia torque and the CVT ratio change response lag in acceleration. In order to compensate for drive torque time delay due to CVT response lag, two algorithms are presented: (1) an optimal engine torque compensation algorithm, and (2) an optimal engine speed compensation algorithm. Simulation results show that the optimal engine speed compensation algorithm gives better engine operation around the optimal operation point compared to the optimal torque compensation while showing nearly the same acceleration response. The performance of the proposed engine-CVT integrated control algorithms are compared with those of conventional CVT control, and It is found that optimal engine operation can be achieved by using integrated control during acceleration, and improved fuel economy can be expected while also satisfying the driver's demands.

• Journal of Power Electronics
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• v.12 no.2
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• pp.294-304
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• 2012

This paper proposes a fuzzy speed tracking controller and a fuzzy rotor angular acceleration observer for a surface-mounted permanent magnet synchronous motor (SPMSM) based on the Takagi-Sugeno (T-S) fuzzy model. The proposed observer-based controller is robust to load torque variations since it utilizes rotor angular acceleration information instead of the load torque value. Linear matrix inequality (LMI) sufficient conditions are given to compute the gain matrices of the speed tracking controller and the observer. In addition, it is mathematically verified that the proposed observer-based control system is asymptotically stable. Simulation and experimental results are presented to confirm that the proposed control algorithm assures a better transient behavior and less sensitivity under model parameter variations than the conventional PI control method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.351-356
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• 2011

Some materials show the character of rigid body in low frequency spectrum. The rigid body motions are consisted of translational and rotational motions. Especially, we can get the acceleration or displacement of a random point in the rigid body by analyzing rigid body transfer matrix at the car's engine and power train. Actually it is difficult to measure the acceleration by attaching the sensor inside of the engine and power train. So the hard to predict acceleration data can be achieved attaching the sensor on the outside of the engine and power train by analyzing the data of rigid body motion which the engine is operated using dynamo. Also this paper will show the change of predicted data and accuracy variation by not using all the measured data but a few exceptions of the point number.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.1067-1072
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• 1996

Sensitivity analysis of the cylindrical zigzag cams under acceleration and centrifugal forces is performed. A Lagrangian method is used to determine the mechanism constant of zigzag track, And the equation of motion for cylindrical zigzag cam under rectangular pulse is derived by the governing equations of a single spring mass system. The ratio of the drive force tn resisting force is derived by angular acceleration, centrifugal force and setback force on the operation of the munition. The theoretical sensitivity curves for 3 models are analyzed. And experiments for 3 models are conducted to check safe and functional zone. Zigzag cam types can be satisfied all major design requirements for switch system of munition.

• International Journal of Highway Engineering
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• v.17 no.3
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• pp.125-132
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• 2015

PURPOSES : The present study aims to evaluate the added $CO_2$ emissions incurred from accelerating operation when to increase the speed up to the allowed level. METHODS : The methodology used are basically the relationship between emission rates and vehicle speeds or acceleration rate. These rates together are used to calculate the added $CO_2$ emissions incurred from accelerating operation. RESULTS : It was resulted that the all the emission rates are increasing proportionally to vehicle speeds or acceleration rates. Additionally, it was also resulted that allowable speeds increasing, the added emission rates are increasing rapidly. CONCLUSIONS : It may be concluded that if the allowable speed ranges are managed, $CO_2$ emissions during vehicle operation are much reduced. From this reason, it was found that the allowable speed during highway design and operation would be much necessary

• Journal of The Korean Astronomical Society
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• v.34 no.4
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• pp.293-295
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• 2001

A numerical scheme that incorporates a self-consistent cosmic-ray (CR, hereafter) injection model into the combined gas dynamics and CR diffusion-convection code has been developed. The hydro/CR code can follow in a very cos-effective way the evolution of CR modified shocks by adopting subzone shock-tracking and multi-level Adaptive Mesh Refinement techniques. The injection model is based on interactions of the suprathermal particles with self-generated MHD waves in quasi-parallel shocks. The particle injection is followed numerically by filtering the diffusive flux of suprathermal particles across the shock to upstream region according to a velocity-dependent transparency function, which represents the fraction of leaking suprathermal particles. In the strong shock limit of Mach numbers $\ge$20, significant physical processes such as the injection and acceleration seem to become independent of M, while they are sensitively dependent on M for M < 10. Although some particles injected early in the evolution continue to be accelerated to higher energies, the postshock CR pressure reaches a time asymptotic value due to balance between acceleration and diffusion of the CR particles.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.6
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• pp.651-656
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• 2014

This paper presents a compensation method for an accelerometer to measure acceleration data accurately when a robot manipulator moves slowly. Although the accelerometer works fine under the fast movement of a robot manipulator, low cost accelerometers provide relatively inaccurate acceleration data under slow movements. In order to correct the error of the sensor data in the slow motion, correction factors are obtained experimentally. Then those corrected data are used for the disturbance observer. Experimental studies of the position control of a robot manipulator are conducted by applying the DOB (Disturbance Observer) control using corrected acceleration data.

• Coupled systems mechanics
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• v.4 no.1
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• pp.19-36
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• 2015

Modelling and analysis of a brick masonry building involves uncertainties like modelling assumptions and properties of local material. Therefore, it is necessary to perform a calibration to evaluate the dynamic properties of the structure. The response of the finite element model is improved by predicting the parameter by performing linear dynamic analysis on experimental data by comparing the acceleration. Further, a nonlinear dynamic analysis was also performed comparing the roof acceleration and damage pattern of the structure obtained analytically with the test findings. The roof accelerations obtained analytically were in good agreement with experimental roof accelerations. The damage patterns observed analytically after every shock were almost similar to that of experimental observations. Damage pattern with amplification in roof acceleration exhibit the potentiality of earthquake resistant measures in brick masonry models.

• Journal of Industrial Technology
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• v.20 no.B
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• pp.189-194
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• 2000

In this paper, we present a BLDC Motor control for needle positioning and velocity control in the industrial sewing machine. In the industrial sewing machine, the fast acceleration control is needed, especially for a person who has a skill in operation of sewing machine for more products. And it is also needed to have a less noise and vibration. But the system which is made in a low price has no feedback system for a current control. Therefore we propose the method of velocity pattern that has an acceleration of velocity and Anti-windup algorithm. By the experiment, we confirmed that these manner have a good performance for low noise, low vibration and fast acceleration in the industrial sewing machine.