ENGINEERING NEWS IN BRIEF

======================================================================

                  ENGINEERING NEWS IN BRIEF
                        E-Mail Newsletter

                               No.46
             Issued by the Asian TOP Panel, October 2005

           The Chinese Mechanical Engineering Society (CMES)
           The Institution of Engineers, Indonesia (PII)
           The Japan Society of Mechanical Engineers (JSME)
           The Korean Society of Mechanical Engineers (KSME)

======================================================================

    According to the agreement made in the 2nd Asian TOP Panel Meeting,
the ENGINEERING NEWS IN BRIEF (E-mail newsletter) has now been edited
by the KSME for the year 2005.

======================================================================

[Contents]

(1) Optimization Design for Cushion System for High-speed Cylinder with Self-adaptive Capacity Based on Genetic Algorithms (Source: CMES)
(2) Determining Method of Feasible Clamping Regions for Fixtures (Source: CMES)
(3) Research on the Integrated Process and Methodology Model of DFQ (Source: CMES)
(4) Development of Systems Using Photovoltaic and Thermal Hybrid Collectors (Source: JSME)
(5) Digital Copy Milling - Architecture for Evolutional Machine Tools (Source: JSME)
(6) Safe Arm Design with MR-based Passive Compliant Joints and Visco-elastic Covering for Service Robot Applications (Source: KSME)

========================================================================

(1) Optimization Design for Cushion System for High-speed Cylinder with Self-adaptive Capacity Based on Genetic Algorithms (Source: CMES)

Li Zhe Wang Zuwen Baogang Harbin Institute of Technology

The self-adaptive cushion system was researched including cushion valve based on pressure feedback by Prof. Li Zhe, Prof. Wang Zuwen and Prof. Baogang. The optimization design for cushion valve parameters was done by means of genetic algorithms. The emulation results show that the optimization method is correct and the optimization effectiveness is very striking. The experimental results show that the cushion system makes the high-speed cylinder’s piston reach the destination at speed between 0.01~0.38m/s when the piston speed varies between 2.76~3.34m/s, and the self adaptive cushion is realized when the piston speed varies.

========================================================================

(2) Determining Method of Feasible Clamping Regions for Fixtures (Source: CMES)

Tian Shaopeng Wu Sen Cao Zhengce Wuhan University of Technology
Huang Zhengdong Huazhong University of Science and Technology

An approach was presented for determining the feasible clamping regions of fixtures. This approach can find the feasible clamping regions according to form ? closure for workpiece with a pre-defined 3-2-1 locator configuration. This method is more suitable to deal with the cases with concave clamping faces than traditional convex- combination based methods. An example is included to illustrate effectiveness of the proposed approach.

========================================================================

(3) Research on the Integrated Process and Methodology Model of DFQ (Source: CMES)

Duan Guijiang Tang Xiaoqing Beihang University

The process and methodology model of DFQ was studied. To promote the integrity and systematization level of DFQ process, a concept called Integrated DFQ ( design for quality )was introduced, in which the product development process was studied as a whole-lifecycle-oriented, multi-factors-targets-optimization process. Based on analysis of the relationship between DFQ methods and tools, the process and methodology framework of Integrated DFQ is constructed, in which the main process of DFQ ( such as quality planning, quality optimization, design quality evaluation, design quality improvement, design quality control, etc.) are integrated by a uniform data structure.

=======================================================================

(4) Development of Systems Using Photovoltaic and Thermal Hybrid Collectors (Source: JSME)

Sadasuke Ito, Kanagawa Institute of Technology

It is important to increase the demand of solar heat as well as photovoltaic PV power in order to reduce the consumption of fossil fuel. The efficiency of converting solar radiation energy to useful heat by collectors is about 40 to 50%. However, the conversion efficiency of a PV module is about 10%. Most of solar radiation energy is dissipated to the ambient air.
Since the space for receiving solar radiation effectively is not large for a common Japanese house, it would be effective to use dissipated this heat for space heating and hot water supply. Photovoltaic and thermal hybrid (PV/T) collectors were designed and two types of them were made for commercial use. A residential house that used thin steel sheets with amorphous silicon solar cells bonded on the upper surfaces for heating air was constructed for commercial use in 1997. A house that adopted PV/T collectors through which antifreezing liquid flowed was also made commercially. The liquid was used to heat the water in a storage tank. PV/T collectors were also used for evaporating the refrigerant of heat pumps. The performance of this type of heat pump has been investigated.

============================================================

(5) Digital Copy Milling - Architecture for Evolutional Machine Tools (Source : JSME)

Keiichi Shirase, Kobe University

A technique called digital copy milling has been developed to control an NC machine tool in real time. The control principle of the digital copy milling is based on one of the traditional copy milling. The digital copy milling system can generate cutter locations and tool paths in real time. Therefore, the NC machine tool equipped with the digital copy milling system can perform milling operation without any NC program. Additionally, not only feed speed, but also the radial and axial depths of cut can be adapted to keep the predetermined cutting torque.
Also, the digital copy milling system can generate new tool paths to complete the milling operation after recovery from a cutting trouble.
A flexible-process and operation-planning system has been developed to perform flexible milling operation. The flexible process and operation planning system can generate a production
plan from the Total Removal Volume (TRV), which is extracted from the initial and finished shapes of the product, and the TRV is divided into machining primitives or machining features.
This system can generate operation sequence and select cutting tool according to the machining features detected. This system integrated with the digital copy milling system can realize an evolutional machine tool that can achieve an autonomous and flexible milling operation.

============================================================

(6) Safe Arm Design with MR-based Passive Compliant Joints and Visco-elastic Covering for Service Robot Applications (Source : KSME)

Dr. Sangchul Kang and his colleagues proposed a new safe arm with passive compliant joints with springs and dampers and a soft covering for human-robot interaction in a recent issue of Journal of Mechanical Science and Technology (vol. 19, p.1835). The spring component can attenuate force to be applied to a human. A developed joints has a feature that magneto-rheological dampers are used. The dampers play a role of suppressing the vibration from the rotary spring. An efficient tuning method to convert the Coulomb friction property of the dampers into a viscous damping one and a position control method with gravitational compensation was proposed. By simulations using a simplified model, a visco-elastic cover was selected, which attenuates impact force to a human below a pain tolerance limit and has a high percentage of absorbency of impact momentum. Finally, force attenuation and damping effects of vibration of the arm have been verified through experiments.

============================================================

Editor : Professor Mansoo Choi of Seoul National University,
           Director of General Affairs, KSME
           ksme@ksme.or.kr