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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Drive and Control
Journal Basic Information
Journal DOI :
Korea Society of Fluid Power & Construction Equipments
Editor in Chief :
Volume & Issues
Volume 11, Issue 4 - Dec 2014
Volume 11, Issue 3 - Sep 2014
Volume 11, Issue 2 - Jun 2014
Volume 11, Issue 1 - Mar 2014
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Position Control of Electro Hydraulic Actuator (EHA) using an Iterative Learning Control
Nam, D.N.C. ; Tri, N.M. ; Park, H.G. ; Ahn, K.K. ;
Journal of Drive and Control, volume 11, issue 4, 2014, Pages 1~7
DOI : 10.7839/ksfc.2014.11.4.001
This paper presents the development of a compact position generator to be used for industrial purposes based on a pump controlled Electro-Hydraulic Actuator (EHA), which is closed-loop controlled by an embedded based Iterative PID controller. The controller is designed by combining the PID controller and the iterative learning scheme to perform tracking control for periodically desired references. Control algorithm is implemented on an embedded computer (AD 7011-EVA) which makes the implementation and application in industrial environments easier.
A Study on Simulation of Shift Sensitivity of Small Forklift Transmission using Direct Control Method
Jeong, Y.M. ; Yang, S.Y. ;
Journal of Drive and Control, volume 11, issue 4, 2014, Pages 8~14
DOI : 10.7839/ksfc.2014.11.4.008
The transmission control method of a small forklift is classified into a pilot control method and a direct control method. In the pilot control method, the complex hydraulic circuit consists of many components, making the production process too costly and time consuming. The direct control method contains fewer components that can be configured to simple hydraulic circuits. As another advantage, the input profile easily changes the shift sensitivity of the transmission. Therefore, this research considers the characteristics of the direct control method in the development of hydraulic system design. This paper will present a simulation of the direct control transmission using AMESim. First, modeling of the direct control method is obtained and simulated with real parameters. The simulation results then are carried out and compared with the experimental results to verify and analyze the characteristics of the direct control method.
An Analysis on Volumetric Displacement of Gerotor Hydraulic Motor using Energy Conservation and Torque Equilibrium - Second Report: The Case of a Revolving and Rotating Inner Rotor -
Kim, S.D. ; Kim, D.M. ; Ham, Y.B. ;
Journal of Drive and Control, volume 11, issue 4, 2014, Pages 15~24
DOI : 10.7839/ksfc.2014.11.4.015
It is difficult to analytically derive a volumetric displacement formula for a gerotor hydraulic motor due to the complexity of the geometric shape of its gear lobes. This work proposes an analytical method for the volumetric displacement, a relatively easy method based upon two physical concepts: conservation between hydraulic energy and mechanical shaft energy, and torque equilibrium for the rotor's motion. The first research using these concepts was conducted on inner and outer rotors rotating with respect to each rotor axis. This work represents the second report conducted on an inner rotor revolving as a planetary motion on the stationary outer rotor. The formula equations regarding the volumetric displacement and flow rate are derived, and the proposed formula about the volumetric displacement is proven to be the same as another analytical displacement formula: the so-called vane length method. From the formula, volumetric displacement is calculated for an example geometry of the gear lobes. The resultant displacement is confirmed to be the same as the value calculated from the chamber volume method. The proposed analytical formula can be utilized in the analysis and design of gerotor hydraulic motors. Because it is based on torque equilibrium, this formula can provide a better understanding of torque performance, such as torque ripple, in designing a gerotor type motor.
Performance Improvement of a Swash Plate Type Piston Pump in the Low-Speed Range by a DLC Coating
Hong, Y.S. ; Kim, J.H. ; Lee, S.L. ;
Journal of Drive and Control, volume 11, issue 4, 2014, Pages 25~31
DOI : 10.7839/ksfc.2014.11.4.025
This paper details application of a DLC(Diamond Like Carbon)-coating to the swash plate and the ball joint of pistons that make sliding contact with the piston shoes of an axial piston pump. This process, aimed to reduce the frictional and leakage power losses of the hydrostatic piston shoe bearings at the low speed range. At lower speeds than 100rpm, the positive effects of the DLC-coating on the power loss reduction of the hydrostatic piston shoe bearings could be confirmed. These effects resulted in little improvement in volumetric efficiency of the test pump, but the mechanical efficiency could be raised by up to 5% at 100rpm; here, the DLC-coated swash plate played a more dominant role than the DLC-coated ball joint.
Optimal Design of a Quick-Acting Hydraulic Fuse using Genetic Algorithm and Complex Method
Lee, S.R. ;
Journal of Drive and Control, volume 11, issue 4, 2014, Pages 32~38
DOI : 10.7839/ksfc.2014.11.4.032
The hydraulic fuse, which responds to the suddenly increased flow on rupture of a line and shuts off the fluid flow, would prevent large spillage of liquid. The quick-acting hydraulic fuse, which is mainly composed of a poppet, a seat, and a spring, must be designed to minimize the leaked flow and to prevent high collision speed between the poppet and seat during fuse operation on a line rupture. The optimal design parameters of a quick-acting hydraulic fuse were searched using the genetic algorithm and the complex method that are kinds of constrained direct search methods. The dynamic behavior of a quick-acting hydraulic fuse was researched using computer simulations that applied the obtained optimal design parameters.
A New Approach to the High Efficiency of Hydraulic Excavator
Lee, Y.B. ;
Journal of Drive and Control, volume 11, issue 4, 2014, Pages 39~45
DOI : 10.7839/ksfc.2014.11.4.039
With recent oil price increases, the fuel efficiency of hydraulic excavators has become a serious issue. Researchers have considered weight lightening by high pressurization in order to improve the efficiency of the excavator and pump controlled actuation (PCA) and to reduce pressure loss of hybrid and valves using mechanical inertia. However, high pressurization is not very effective because the excavator operates at a low speed; a hybrid is inefficient because little accumulated inertial energy is accumulated; and PCA is ineffective because control precision and responsibility are low. In this study, a method to minimize air and gas in hydraulic oil has been presented as a simple and new way to increase hydraulic efficiency.
A Study on Design of Small Type Screw Decanter using Commercial Analysis Tool
Kim, Y.S. ; Kim, J.T. ; Yang, S.Y. ;
Journal of Drive and Control, volume 11, issue 4, 2014, Pages 46~52
DOI : 10.7839/ksfc.2014.11.4.046
This study suggests a small-sized screw decanter specialized for dredging sites. Generally, conventional screw decanters are composed of a cylinder and a cone. However, the suggested screw decanter simply has a cone based on a cone-type bowl structure. In this research, a commercial analysis tool is used to establish an optimal design for the bowl and the screw conveyor. Moreover, the base frame, where the main bearings that support the spindle of the bowl and the screw conveyor are installed, is optimally designed considering the weight of the rotating body and the deflection caused by the high centrifugal force. Furthermore, the natural frequency range of the spinning body, the bowl and the screw conveyor, is applied to this base frame; it is designed not to correspond to the resonance frequency range and achieves stability as a result. This study suggests an optimal design for the rotating body and the base frame of a screw decanter considering its vibration characteristics. Such a design will prevent overuse of materials and help to reduce the weight and volume-and the price-of a screw decanter.
Reduction of Power Consumption for Constant Pressure Control of Variable Swash Plate-type Piston Pump by Varying the Pump Speed
Kim, J.H. ; Hong, Y.S. ;
Journal of Drive and Control, volume 11, issue 4, 2014, Pages 53~60
DOI : 10.7839/ksfc.2014.11.4.053
This paper proposes a control scheme to reduce the power consumption of a variable displacement swash-plate type piston pump supplying oil to a valve-controlled hydraulic cylinder at constant pressure. Whenever flow rate demand was absent, the swash plate angle and the pump speed were changed to the minimum values required to compensate for the internal leakage flow. In response to command signals, the pump speed was changed in proportion to the absolute mean value of the speed component for position commands. At the same time, a pressure regulator was activated to maintain constant system pressure by precisely adjusting the pump speed with the swash plate angle fixed at the maximum. The conventional system consisting of a pressure-compensated variable displacement type pump is driven at a constant speed of 1,800rpm. By comparison, computer simulation and experimental results showed that idling power at stand-by status could be reduced by up to 70% by reducing the pump speed from 1,800rpm to 300rpm and the swash plate angle to the minimum.
Development of Performance Test Equipment for Easy-Hill Assist Valve
Jung, G.H. ;
Journal of Drive and Control, volume 11, issue 4, 2014, Pages 61~67
DOI : 10.7839/ksfc.2014.11.4.061
When a manual transmission equipped car stops on an incline where the nose of the car is higher than the rear, hill-start control or hill-holder could prevent the vehicle from rolling backward as the car moves forward. The easy-hill assist valve consists of a check valve and a needle type ON/OFF solenoid valve connected in parallel; it is a hydraulic actuator that can maintain brake pressure using an electrical signal from the ECU. As the EHA valve is a safety-related component of the brake system, high reliability as well as superior dynamic performance is required for it to be applied in commercial vehicles. This paper presents the design of the EHA valve as a piece of equipment that can simulate the brake actuation pressure with a pressurizing piston. Following specific test standards, the experimental results validate the implemented functions of the test equipment, proving the test stand to be effective for the performance and endurance of the EHA valve.