• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.4
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• pp.805-815
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• 1994

The development of automatic production systems has a trend toward Computer Integrated Manufacturing System(CIMS) in recent years. In hardware configuration, CIMS are composed of intelligent CAD/CAM work stations, multifunction CNC machining centers including material handling systems. The DNC systems present the key element of automation hierarchy in a FMS. A DNC system is one which connects a number of numerically-controlled machines to a common memory in a digital computer for part program storage with provision for on-demand distribution of part program data to machines using communication in hierarchical structure of central computer, control computer and cell controller. This paper describes the development of Behind-the-Tape-Reader(BTR) type DNC system using CYBER 180-830 as a central computer and IBM PC-386 cell control computer and NC lathe with FANUC 5T NC controller. In this system, the connection between central computer and cell control computer is done via RS-232C serial interface board, and the connection between cell control computer and FANUC 5T controller is done via parallel interface board. The software consists of two module, central computer communication module for NC program downloading and status uploading, NC machine running module for NC operating.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1276-1277
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• 2006

The ever increasing requirements on today's compacts with regard to their geometry and precision call for flexible high-precision and most capable production systems. DORST Technologies has coped with these requirements by developing the new HP series for pressing forces between 1600 kN and 16000 kN and the new HS series for pressing forces between 150 kN and 1200 kN. These fully hydraulic presses featuring upper ram, lower ram, core rod, filler, up to 4 lower tool levels and up to 4 upper tool levels with closed-loop controlled movements. Thanks to latest servo technology and an electronic bus system it is possible to have all movements closed-loop controlled in the desired relation to each other. Thus, today's hydraulic presses provide high stroke rates, low energy consumption and a user-friendly interface. The input of data is carried out via clearly arranged screen masks on a touch-screen. The innovative DORST $IPG^{(R)}$ (Intelligent Program Generator) has been designed to support the set-up staff in preparing and optimizing the toolprogram. The combination of the machine type with the hydraulic unit determines the productivity in consideration of the specific application and the part to be pressed. Thanks to the closed-loop control circuits, DORST hydraulic automatic presses of the latest generation ensure unmatched precision and repeatability - and consequently process reliability - often without necessitating subsequent machining steps.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.1
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• pp.73-80
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• 2000

The stewart platform manipulator proposed by stewart is the parallel manipulator which is composed of several independent actuators connecting the upper plate with the base plate and capable of executing a six degree of freedom motion. The manipulator has a structure of a closed loop form, and provides better load-to-weight ratio and ratio and rigidity than a serial manipulator with an open loop form. Moreover, the manipulator has high positional accuracy because position errors of actuators are not additive. Because of these advantages, this manipulator is widely used in many engineering applications such as a driving simulator, a tool of machining center, a force/torque sensor and so on. When this Stewart platform manipulator is controlled in joint space, it is difficult to design a controller using an analytic method due to nonhnearity and unknown parameters of actuators. Therefore, a PID controller is often used because of easiness in applications. To find the PID control gain, a trial-and-error method is generally used. This method is time-consuming, and does not guarantee a optimal gain. Thus, this paper proposes a GA-PID controller which selects an optimal PID control gain using genetic algorithms. And this proposed controller is evaluated experimentally and shows acceptable performance.