Study of rocking motion of rigid body with slide contact

The purpose of this study is to formulate the motion of a rigid body with unilateral contact problems by applying techniques of multibody dynamics and to analyze the issue of rocking condition of rigid bodies with slide contact. In To investigate rocking motion with slide contact, we formulate for dynamics of a simple rigid body system with a unilateral contact model. Judgment for the occurrence of contact between a rigid body and a base is applied. The planar motion of a rigid body system having a simple shape and both with and without slide cases is assumed. Using constraint conditions for the contact as algebraic equations, the rocking motion of the rigid body, including slide and frictional force, is analyzed. The differential algebraic equation is solved by the augmented method with Lagrange multipliers, using generalized coordinates and independent variables that describe the contact points. The influence of the frequency and amplitude of disturbance given to the base is discussed. This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korean, August 20–23, 2008. Keisuke Nozaki is graduate student at Sophia University in Tokyo, Japan. Yoshiaki Terumichi received a Ph.D. degree in Mechanical Engineering from keio University in 1994. Dr. Terumichi is currently a Professor at the Department of Engineering and Applied Sciences at Sophia University in Tokyo, Japan. He is currently contributing as a member of Advisory Boad Eccomas Thematic Conference “Multibody Dynamics 2009” and an editor of the International Journal of System Design and Dynamics of JSME. His research field is on multibody dynamics, vehicle dynamics, and pattern formation phenomena. Kazuhiko Nishimura received a B.S. degree in Aerospace Engineering from the University of Tokyo in 1994. He has worked for the Central Japan Railway Company (CJR) since 1994. As an engineer of the railway industry, he also studied mechanical engineering at the University of Michigan and received his M.S. degree in 2003. He is currently a senior research engineer at Komaki Research Center of CJR and also a Ph. D. candidate at Sophia University. His research/engineering interests are in the area of vehicle/track interaction issues in high speed railway system. Kiyoshi Sogabe received a B.S. degree in Mechanical Engineering from Kyusyu Institute of Technology, Japan. He received M.S. and Dr. Eng degrees from the University of Tokyo in 1971 and 1975, respectively. Dr. Sogabe is currently a Professor in the Department of Engineering and Applied Sciences, Faculty of Science and Technology, Sophia University, Tokyo, Japan. Dr. Sogabe was the Dean of the faculty during April 2004–March 2008. His main research interests are in the field of dynamic analysis of machines and structures, multibody dynamics.     

Experimental validation of steering torque feedback simulator through vehicle running test

This paper describes a force feedback system based on real-time multibody dynamic analysis. This system can provide the analyzed reactive force to the operator through the operational device. In this study, this system is used as a steering torque feedback simulator of an automobile. This simulator can provide the haptic sensation of the steering wheel to the operator. For the purpose of evaluating the validity of the developed simulator, we conducted some vehicle running tests with an experimental electric vehicle. The results of these tests were compared with the results simulated on the steering torque feedback simulator. It was shown that the developed simulator can provide a suitable steering torque to the operator. This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korea, August 20–23, 2008. Dr. Taichi Shiiba received a Doctor of Engineering from The University of Tokyo in 2001. He became an Associate Professor at Meiji University in 2007. A Member of JSME and JSAE, his major areas are multibody dynamics, vehicle dynamics, and driving simulators. Wataru Murata received a B.S. degree in mechanical engineering from Meiji University in 2007. His research interests are vehicle dynamics, real-time analysis, and multibody dynamics.     

Investigation and design of a new shock absorbing device that cooperates between two colliding objects

This paper deals with a new type of shock absorbing device that cooperates between two colliding objects. The new device utilizes a four-bar-chain-like articulated mechanism with some possible actuations. The devices are assumed to be deployed in the pre-crash phase (by sensing and identifying unavoidable collisions) so as to provide an extended deformable region between the two objects. Moreover, by functioning like a four-bar-chain mechanism, they produce a repulsive effect by pushing each other and sliding in the opposite lateral direction. To investigate the capacity of the proposed articulated shock absorbing mechanism, a standard numerical optimization technique called SQP and a new optimization technique called ALPSO are applied. ALPSO is an attractive method for solving multimodal optimization problems based on Particle Swarm Optimization and constraint treatment using an Augmented Lagrange Method. We demonstrate ALPSO and show its applicability to this problem. The optimization process automatically determines the mode of the operation and gives an estimation of the development potential of the new device. This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korea, August 20–23, 2008. Mr. Atsushi Kawaguchi received his B.S. and M.S. degrees in Engineering from Hiroshima University in 2001 and 2003, respectively. Mr. Kawaguchi is currently a researcher at the Toyota Central R&D Labs., Inc. in Aichi, Japan. His research interests are in the area of engine vibration analysis, multibody dynamics, and vehicle safety. Dr.-Ing Kai Sedlaczek studied Mechanical Engineering at the University of Wisconsin in Madison and at the University of Stuttgart, where he joined the Institute of Engineering and Computational Mechanics in 2002. There, he received his doctorate in Mechanical Engineering in 2007. His main fields of interest are multibody systems, optimization and vehicle dynamics. Dr. Atsushi Kawamoto received an M.Sc. degree from the department of Mechanical Engineering, Nagoya University in 1995. He then went on to receive his Ph.D. degree from the department of Mathematics, Technical University of Denmark in 2005. Dr. Kawamoto is currently a researcher at the Toyota Central R&D Labs., Inc. in Aichi, Japan. Dr. Kawamoto’s research interest areas are in topology and shape optimization, multibody dynamics and multiphysics. Prof. Peter Eberhard received his Dipl.-Ing. in Mechanical Engineering, his Dr.-Ing. and his Habilitation in Mechanics from the University of Stuttgart in Germany. In 2000 he was appointed as professor of Mechanics and System Dynamics at the University of Erlangen-Nuremberg before he became full professor and director of the Institute of Engineering and Computational Mechanics at the University of Stuttgart in 2002. In 2000 he received the Richard-von-Mises award and in 2007 an Honorary Professorship at the Nanjing University of Science and Technology, P.R. China. Prof. Eberhard’s research interests include multibody dynamics, contact mechanics, mechatronics, optimization and biomechanics.     

Hybrid neural network bushing model for vehicle dynamics simulation

Although the linear model was widely used for the bushing model in vehicle suspension systems, it could not express the nonlinear characteristics of bushing in terms of the amplitude and the frequency. An artificial neural network model was suggested to consider the hysteretic responses of bushings. This model, however, often diverges due to the uncertainties of the neural network under the unexpected excitation inputs. In this paper, a hybrid neural network bushing model combining linear and neural network is suggested. A linear model was employed to represent linear stiffness and damping effects, and the artificial neural network algorithm was adopted to take into account the hysteretic responses. A rubber test was performed to capture bushing characteristics, where sine excitation with different frequencies and amplitudes is applied. Random test results were used to update the weighting factors of the neural network model. It is proven that the proposed model has more robust characteristics than a simple neural network model under step excitation input. A full car simulation was carried out to verify the proposed bushing models. It was shown that the hybrid model results are almost identical to the linear model under several maneuvers. This paper was recommended for publication in revised form by Associate Editor Hong Hee Yoo Dr. Wan-Suk Yoo was born in 1954, and received B.S. degree from Seoul National University (1976), and got M.S. degree from KAIST (1978) and Ph.D. from the University of Iowa (1985). He is currently a full professor at the Pusan National University in Korea, where he joined since 1978. His major area is vehicle dynamics and flexible multibody dynamics. He became an ASME Fellow (2004), and currently serving as an associate editor for the ASME, J. of computational and nonlinear dynamics. He is also serving a contributing editor for the multibody system dynamics journal. He is serving as ISC chair for the ACMD2008, and a member at IFToMM TC for multibody dynamics. He is currently a vicepresident of the KSME (Korean Society of Mechanical Engineers).     

Stabilization of a bicycle with two-wheel steering and two-wheel driving by driving forces at low speed

Recently, the personal mobility vehicle (PMV), a vehicle suitable for personal use, has been developed. It moves at low speed and is sufficiently small that it can be ridden in pedestrian space. This vehicle is expected to be a new method of transportation that is practical and environmentally friendly. As one form of PMV, the authors propose a twowheel vehicle with two modes: a two-wheel steering and two-wheel driving bicycle mode and a parallel two-wheel mode. This vehicle has four electric motors, two for driving and two for steering, and one generator connected to the pedals. In the bicycle mode, the rider rotates the pedals to generate electric power, and the motors in the wheels produce torque using the generated energy. The front and rear wheels are steered by the electric motor according to the angle of the handle. Therefore, this bicycle is controlled by a steer-by-wire and a drive-by-wire system. In the parallel two-wheel mode, the vehicle is stabilized according to the theory of the inverted pendulum. In this paper, we focus on the bicycle mode and analyze its stability. Stabilizing the bicycle is not easy since the proposed vehicle has tires with small diameters and the traveling speed is assumed to be low. It is known that the stability of bicycles is tuned by adjusting the bicycle parameters and changing the rear steer angle. However, since we aim to use the vehicle in a narrow walking space at low speed, such conventional methods are not always suitable. The authors propose the stabilization of the bicycle using driving forces and design a controller using linear-quadratic control theory. The results of the numerical simulations show the proposed method is effective in stabilizing the bicycle. This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korea, August 20–23, 2008. Chihiro Nakagawa received her M.S. degree in Department of Engineering Synthesis from University of Tokyo, Japan, in 2007. She is currently a doctoral student at the department at University of Tokyo and serves as a JSPS Research Fellow. Yoshihiro Suda received his Dr. Eng. degree in Department of Engineering Synthesis from University of Tokyo, Japan, in 1987. He is currently a Professor at the Institute of Industrial Science and the Director of Chiba Experiment Station, University of Tokyo. Kimihiko Nakano received his Dr. Eng. degree in Department of Engineering Synthesis from University of Tokyo, Japan, in 2000. He is currently an Associate Professor at the Institute of Industrial Science, University of Tokyo. Shoichiro Takehara received his Dr. Eng. degree in Department of Engineering Synthesis from Sophia University, Japan, in 2004. He is currently an Assistant Professor at the Department of Mechanical Engineering at Tokyo Metropoli-tan University.     

Model-based fault detection and isolation in steer-by-wire vehicle using sliding mode observer

Steer-by-Wire system (SbW), in which the conventional mechanical linkages between the steering wheel and the front wheel are removed, is suited to active steering control, improving vehicle stability, dynamics and maneuverability. And SbW is implemented to autonomous steering control to assist the driver. However, the SbW vehicle contains unsolved important problems about fault tolerant function. For example, it is the detection of sensor fault and multiplicative fault simultaneously. Fault detection and isolation (FDI) is essential in fault-tolerant problems, and conventional FDI for SbW was based on Kalman filter. But this method has weak robustness and cannot detect sensor fault and multiplicative fault simultaneously. We propose a novel model-based fault detection and isolation method using sliding mode observer in the SbW vehicle, which contains measurement of sensor fault and multiplicative fault. The effectiveness of the proposed method is verified by simulations. This paper was recommended for publication in revised form by Associate Editor Kyoungsu Yi Jae-Sung Im was born in Busan, Korea in 1978. He received his B.S. and M.S. degrees in Mechanical Engineering from Pukyong National University, Korea, in 2003 and 2005, respectively. He then received his Ph.D. degree from Kumamoto University, Japan, in 2009. His interests are in vehicle dynamics, robust control, fault detection and isolation, and man-machine interface. Fuminori Ozaki received the B.S. and M.S. degrees from the Department of Computer Science, Kumamoto University, Japan, in 1998 and 2000. In 2000, he joined OMRON Corporation, Kyoto, Japan, where he developed semiconductor manufacturing equipment. His current interests include EPS control and KANSEI engineering. Tae-Kyeong Yue received the B.S. and M.S. degrees from Pukyong National University, Korea, in 1998 and 2000, respectively. He received the Ph.D. degree from Kumamoto University, Kumamoto, Japan in 2003. He is working in the Korea Ocean Research and Development Institute (KORDI), Korea. His interests are fault detection and isolation, decentralized control and control of deep-sea mining system. Shigeyasu Kawaji received his Master of Engineering in Electrical Engineering and Doctor of Engineering in Control Engineering from Kumamoto University and Tokyo Institute of Technology, Japan, in 1969 and 1980, respectively. He joined the Department of Electronic Engineering of Kumamoto University, Japan, where he is presently as a full professor. He is the Director of System Integration Laboratory. He is presently the President of Advanced Health Laboratory Ltd. His current research interest includes robust control, intelligent control mechatronics and robotics, fusion of medicine and engineering, and automotive mechatronic systems.     

Development of a motion simulator for testing a mobile surveillance robot

A 6-axis motion simulator has been developed, in order to regenerate UGV (unmanned ground vehicle) motion and to test the stabilization system of the mobile surveillance robot that is mounted on the UGV. For developing the 6-axis motion simulator, a simulation-based design procedure was introduced. The 3D geometric model of the motion simulator was created by using 3D CAD modeler ProE. The multibody dynamics model of the motion simulator has also been created by using the general purpose dynamic analysis program ADAMS to validate the design of the motion simulator. Dynamics and control co-simulation model for the motion simulator has been also established for control performance analyses. Actual hardware of the motion simulator has been fabricated based on the proposed simulation based design. Hardware test of the motion simulator has been tried to validate the design. This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korea, August 20–23, 2008. Oskar Wallrapp was awarded a Ph.D. degree in Mechanical Engineering at the Technical University of Berlin, Germany in 1989. Dr. Wallrapp is currently a Professor in the Department of Precision and Micro Engineering, Muenchen University of Applied Science, Munich, Germany. His research interests are mechanism analysis and design, robotics, and bio-mechanics. Sung-Soo Kim received a Ph.D. degree in Mechanical Engineering from the University of Iowa in 1988. Dr. Kim is currently a Professor in the Department of Mechatronics Engineering at Chungnam National University in Daejeon, Korea. His research interests are real-time multibody formulation and its application to the automotive systems and military robot systems.     

Study on side collision reconstruction using database based on deformed shape information

A side collision reconstruction algorithm using a database based on the deformed shape information from experiments is suggested. A deformation index related to the deformed shape is developed to set the database for the side collision reconstruction algorithm. Two small-sized model cars are developed to carry out the side collision test. Several side collision tests according to velocities and collision angles are performed for establishing side collision database. A high speed camera with 1000fps is used to capture the motion of the car. Side collision reconstruction algorithm is developed and applied to find the collision conditions before the accident occurred. Several collision cases are tested to validate the database and the algorithm. A database from computer simulation is verified with experiments. According to comparing errors between simulation and experiment, it is satisfied within 6.6%. This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korea, August 20–23, 2008. Dr. Jeong-Hyun Sohn received his B.S. degree from Pusan National University (1995), M.S. from PNU (1999), and Ph.D. from PNU (2002). He is currently an associate professor in the department of Mechanical Engineering at Pukyong National University in Busan, Korea. He is currently serving as a board member of dynamics and control division, KSME. His major area is vehicle dynamics and flexible multibody dynamics. Dr. Wan-Suk Yoo received his B.S. degree from Seoul National University (1976), M.S. from KAIST (1978) and Ph.D. from University of Iowa(1985). He is professor at Pusan National University, and currently serving as a vice president in KSME. His major area is vehicle dynamics and flexible multibody dynamics.     

Sensitivity of a vehicle ride to the suspension bushing characteristics

The sensitivity of the ride characteristics of a road vehicle to the mechanical characteristics of the bushings used in its suspension is discussed here. First, the development and computational implementation, on a multibody dynamics environment, of a constitutive relation to model bushing elements associated with mechanical joints is presented. Bushings are made of a rubber type of material, which presents a nonlinear and viscoelastic relationship between the forces and moments and their corresponding displacements and rotations. Suitable bushing models for vehicle multibody models must be accurate and computationally efficient, leading to more reliable models. The bushing is modeled in a multibody code as an arrangement of springs that penalize the motion between the bodies connected. In the methodology proposed here, a finite element model of the bushing is developed in the framework of a finite element (FE) code to obtain the curves of displacement/rotation versus force/moment for different loading cases. The basic ingredients of the multibody model are the same vectors and points relations used to define kinematic constraints in any multibody formulation. Spherical, cylindrical and revolute bushing joints are developed and implemented in this work, since the methodology is demonstrated through the ride over bumps, at different speeds, of two multibody models of a road vehicle: one with perfect kinematic joints, for the suspension sub-systems; the other with bushing joints, riding. Then, sensitivities of different vehicle kinematic responses to the characteristics of the bushings used in the suspension are evaluated, by using numerical sensitivities. Based on the sensitivity analysis, indications on how to modify the vehicle response by modifying the bushing characteristics are drawn. This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korea, August 20–23, 2008. Jorge A.C. Ambrósio received his Ph.D. degree from the University of Arizona in 1991, being currently Professor at the Mechanical Engineering Department of Instituto Superior Técnico at the Technical University of Lisbon, Portugal. He is the author of several books and a large number of papers in international journals in the areas of multibody dynamics, vehicle Dynamics, crashworthiness and biomechanics. He has been responsible for several international projects in railway dynamics, biomechanics and passive safety. Currently he is the Editor-in-Chief of Multibody System Dynamics and member of the editorial boards of several international journals.     

A recursive subsystem synthesis method for repeated closed loop structure in multibody dynamics

A recursive subsystem synthesis method has been proposed for efficient analysis for a repeated closed loop structure in multibody dynamics. Virtual work form of equations of motion has been used to reduce subsystem equations of motion. Position, velocity, and acceleration analyses are carried out subsystem by subsystem in the forward recursive fashion. Effective mass matrices and force vectors are computed subsystem by subsystem in the backward recursive fashion. An excavator example is used for a repeated closed loop structure to validate the proposed method. This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korea, August 20–23, 2008. Sung-Soo Kim received a B.S. degree in Agricultural Engineering from Seoul National University in 1981. He then went on to receive his M.S. and Ph.D. degrees in Mechanical Engineering from the University of Iowa in 1983 and 1988, respectively. Dr. Kim is currently a Professor in the Department of Mechatronics Engineering at Chungnam National University in Daejeon, Korea. His research interests are real-time multibody formulation and its application to the automotive systems and military robot systems.     

Temperature measurement of microfluids with high temporal resolution by laser-induced fluorescence

Temperature of microfluidic system is greatly sensitive because of fast heat conduction and small heat capacity due to the scale effect. The purpose of this study is the development of a measurement system for the temperature field of liquids in a microfluidic device with high spatial- and temporal-resolution. Measurement method employed in this study is laser-induced fluorescence using fluorescein with the temperature dependence of fluorescent intensity. In order to measure the transient temperature field, an image-intensified high-speed camera was utilized. The signal-to-noise ratio can be improved by the time- or phase-averaging scheme. Applying the synchronization mechanism, phase-averaged temperature data with the time resolution of 500 μs can be obtained. Spatial resolution estimated from the Rayleigh limit was approximately 530 nm. The validity of the developed measurement system was confirmed by the experiments for the transient behavior of the liquid temperature undergoing the laser heating in the microfluidic device. This paper was presented at the 7th JSME-KSME Thermal and Fluids Engineering Conference, Sapporo, Japan, October 2008. Masahiro Motosuke received his B. S. degree from Department of System Design Engineering at Keio University, Japan, in 2001. He received his M. S. and Ph. D degrees from Keio University in 2003 and 2006. He is now an Assistant Professor at Department of Mechanical Engineering in Tokyo University of Science, Japan. His research interests are in the development of advanced sensing and control for the fluid or particle motion and properties in a microfluidic system based on optical or electrokinetic approach. Dai Akutsu received his B. S. degree in Mechanical Engineering from Tokyo University of Science, Japan, in 2008. He is currently in the master course of the graduate school of Mechanical Engineering in Tokyo University of Science. His research interests include the temperature measurement of the highly tiny region in a microfluidic device using micro-LIF and the development of micro- mixer/ sorter by means of electrokinetics. Shinji Honami received his B. S. in Mechanical Engineering from Keio University, Japan, in 1967. He received his M. S. and Ph. D degrees from Keio University in 1969 and 1974, respectively. He is a Professor at School of Engineering, Department of Mechanical Engineering, Tokyo University of Science, Japan. His research interests include turbulent and laminar flow control and microfluidics.     

An improved model-based predictive control of vehicle trajectory by using nonlinear function

A new model-based predictive control algorithm for vehicle trajectory control is proposed by using vehicle velocity and sideslip angle. Based on the error function combined with vehicle velocity and side slip of a bicycle model, a predictive control method has been proven to be useful on low velocity. Thus, it could be applied for an autonomous vehicle without a driver. Although an autonomous robot is not necessary to be driven with a high velocity, a commercial vehicle has to be driven at high velocity. Thus the previous predictive control formulation is not enough for a commercial driving system. This study is proposed to enhance the capacity of the predictive controller for rather high speed vehicles. This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korea, August 20–23, 2008. Mr. Jeong-Han Lee is pursuing a Ph.D. degree in Mechanical Engineering at Pusan National University under the supervision of professor Wan-Suk Yoo. His research interests are focused on the area of adaptive control using multibody dynamics. Dr. Wan-Suk Yoo received his Ph.D. degree in 1985 from the University of Iowa. In 1994, he became a full professor at the Pusan National University, and he was selected an ASME fellow. He is serving as a vicepresident of the KSME.     

Development of rapid mixing fuel nozzle for premixed combustion

Combustion in high-preheat and low oxygen concentration atmosphere is one of the attractive measures to reduce nitric oxide emission as well as greenhouse gases from combustion devices, and it is expected to be a key technology for the industrial applications in heating devices and furnaces. Before proceeding to the practical applications, we need to elucidate combustion characteristics of non-premixed and premixed flames in high-preheat and low oxygen concentration conditions from scientific point of view. For the purpose, we have developed a special mixing nozzle to create a homogeneous mixture of fuel and air by rapid mixing, and applied this rapidmixing nozzle to a Bunsen-type burner to observe combustion characteristics of the rapid-mixture. As a result, the combustion of rapid-mixture exhibited the same flame structure and combustion characteristics as the perfectly prepared premixed flame, even though the mixing time of the rapid-mixing nozzle was extremely short as a few milliseconds. Therefore, the rapid-mixing nozzle in this paper can be used to create preheated premixed flames as far as the mixing time is shorter than the ignition delay time of the fuel. This paper was recommended for publication in revised form by Associate Editor Ohchae Kwon Masashi Katsuki received his B.E. degree in Mechanical Engineering from Osaka University, Japan, in 1965. He received his Dr. Eng. from O. U. in 1985. Dr. Katsuki is currently a Visiting Professor at the Department of Environmental Engineering at Hoseo University in Chungnam, Korea. He was a Vice President of the Japan Society of Mechanical Engineers. Dr. Katsuki’s research interests include combustion, computational thermo-fluid dynamics, and molecular dynamics. Jin-Do Chung received his B. S., M.S. and Ph.D. degrees in Mechanical Engineering from Chungnam University, Korea in 1983, 1985 and 1990. He then received another Ph.D. in Environmental Engineering from Kanazawa University, Japan in 1996. After that he worked as Post-doc researcher for 1,6 year at KIMM and Senior researcher for 6years at KEPCO Research Center. Dr. Chung is currently a Professor at the Department of Environmental Engineering at Hoseo University in Asan, Korea. Dr. Chung’s research interests include thermal-fluid and environmental engineering. Jang-Woo Kim received his B. S. degree in Mechanical Engineering from Chungnam University, Korea, in 1990. He then received his M. S. and Ph. D. degrees from Kyushu University, Japan in 1994 and 1998, respectively. Dr. Kim is currently a Professor at the School of Display Engineering at Hoseo University in Asan, Korea. Dr. Kim’s research interests include CFD, aerodynamics, and display equipment technology. Seung-Min Hwang received the Ph.D. degree in Mechanical Engineering at Osaka University in 2005. After that he worked as visiting researcher for 3 years at CRIEPI (central research institute of electric power industry) and Osaka University in Japan. He is currently a Professor at the Graduate School of Venture at Hoseo University in Korea. His major research is thermal-fluid, energy issue and environment. Seung-Mo Kim received his Ph. D. degrees in Mechanical engineering from Osaka University, Japan, in 2004. Dr. Kim is currently a research Professor at Pusan Clean Coal Center at Pusan National University in Pusan, South Korea. Dr. Kim’s research interests include coal combustion, oxy-fuel combustion, coal gasification, coal de-watering, power generation plant system and energy issues. Chul-Ju Ahn received his B.S. degree in Mechanical Engineering from Hanyang University, Korea, in 1998. He then received his M.S. and Ph.D. degrees from Osaka University, Japan, in 2001 and 2006, respectively. Dr. Ahn is currently a Senior Research Engineer at Samsung Techwin CO. LTD. in Changwon, Korea. Dr. Ahn’s research interests include gas turbine engine, biomass gasification, and power system.     

Volumetric modification of the Hertz contact problem and its application to the multibody dynamics simulation

A method of computational reduction of an elastic contact model for rigid bodies in frame of the Hertz contact model is considered. An algorithm to transform outer surfaces’ geometric properties to the local contact coordinates system is described. It tracks permanently in time the surfaces of the bodies which are able to contact. An approach to compute the normal elastic force is represented. That one deals with the reduction to one transcendental scalar equation that includes the complete elliptic integrals of the first and second kinds. Simulation of the Hertz model was accelerated essentially due to use of the differential technique to compute the complete elliptic integrals and due to the replacement of the implicit transcendental equation by the differential one. Based on the Hertz contact problem classic solution, an invariant form for the force function which depends on the geometric properties of an intersection for undeformed rigid bodies’ volumes, so-called volumetric model, is proposed then. The resulting force function reduced expression is supposed to be in use in cases when the classical contact theory hypotheses are broken. The expression derived has been applied to several cases of the elastic bodies contacting, and in particular back to the source Hertz model itself. This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korea, August 20–23, 2008. Ivan Kosenko received his M. S., Ph. D., and Dr. Sc. degrees, all in Physics and Mathematics, from the Lomonosov Moscow State University, in 1974, 1982, and 2000 years respectively. He is currently a Professor at the Russian State University of Tourism and Service, Moscow region. Simultaneously he performs his duties as a head of the Engineering Mechanics Department. Scope of scientific interests includes: theory of stability, dynamical systems, celestial mechanics, space dynamics, multibody dynamics, simulation of dynamics. Evgeniy Aleksandrov received his M. S. degree in Engineering from Moscow State University of Service, Russia, in 2002. He currently has a position of the senior lecturer at the Russian State University of Tourism and Service, Department of Engineering Mechanics. His main scientific interests are: multibody dynamics, contact mechanics, software for modeling and simulation.     

Sloshing cargo in silo vehicles

The driving stability of silo vehicles is significantly affected by the type of cargo that is transported and the design of the tank. Cargo motion can have both beneficial and negative aspects in terms of driving stability and braking performance. Neglecting the influence of the dynamically moving cargo in driving simulations of silo vehicles leads to significant errors in the simulation results. We propose a new method for the dynamic simulation of silo vehicles carrying granulates. The method couples Lagrangian particle methods, such as the discrete element method, and multibody systems methods using co-simulations. We demonstrate the capability of the new approach by providing simulation results of two benchmark maneuvers. This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korea, August 20–23, 2008. Florian Fleissner received his Dipl.-Ing. degree in Mechanical Engineering from the University of Erlangen, Germany, in 2003. He is currently working as research and teaching assistant, completing his Ph.D. in Mechanical Engineering at the Institute of Engineering and Computational Mechanics at the University of Stuttgart, Germany. Vincenzo D’Alessandro graduated in 2008 in Mechanical Engineering at the Politecnico di Milano, Italy. He is currently working as a Ph.D. candidate in Mechanical Engineering at the department of mechanical engineering at the Politecnico di Milano. Werner Schiehlen was educated as a mechanical engineer and received a Ph.D. on satellite dynamics in 1966. After working for 10 years with the Technical University Munich and spending one year with NASA in the US he was appointed full professor of mechanics with the University of Stuttgart until his retirement in 2002. He published more than 320 scientific papers in applied and computational dynamics including 7 books mostly translated in foreign languages, too. Werner Schiehlen served as President of IUTAM. Since 1997 he is Editor-in-Chief of the international journal MULTIBODY SYSTEM DYNAMICS. Peter Eberhard received his Dipl.-Ing. in Mechanical Engineering, his Dr.-Ing. and his Habilitation in Mechanics from the University of Stuttgart in Germany. In 2000 he was appointed as Professor of Mechanics and System Dynamics at the University of Erlangen-Nuremberg before he became 2002 Full Professor and Director of the Institute of Engineering and Computational Mechanics at the University of Stuttgart. In 2000 he received the Richard-von-Mises award and in 2007 an Honorary Professorship at the Nanjing University of Science and Technology, P.R. China. His research interests include multibody dynamics, contact mechanics, mechatronics, optimization and biomechanics.     

Trajectory control of electro-hydraulic excavator using fuzzy self tuning algorithm with neural network

This paper presents the trajectory control of a 2DOF mini electro-hydraulic excavator by using fuzzy self tuning with neural network algorithm. First, the mathematical model is derived for the 2DOF mini electro-hydraulic excavator. The fuzzy PID and fuzzy self tuning with neural network are designed for circle trajectory following. Its two links are driven by an electric motor controlled pump system. The experimental results demonstrated that the proposed controllers have better control performance than the conventional controller. This paper was recommended for publication in revised form by Associate Editor Kyongsu Yi Le Duc Hanh received the B. S. degree in the department of Mechanical Engineering from Hochiminh City University of Technology in 2006, the M.Sc. degree in Mechanical and Automotive Engineering from University of Ulsan in 2008. His research interests are electro-hydraulic excavator, remote control, intelligent control. Kyoung Kwan Ahn received the B. S. degree in the department of Mechanical Engineering from Seoul National University in 1990, the M. Sc. degree in Mechanical Engineering from Korea Advanced Institute of Science and Technology (KAIST) in 1992 and the Ph.D. degree with the title “A study on the automation of out-door tasks using 2 link electro-hydraulic manipulator from Tokyo Institute of Technology in 1999, respectively. He is currently a Professor in the school of Mechanical and Automotive Engineering, University of Ulsan, Ulsan, Korea. His research interests are hybrid excavator, fluid power control, design and control of smart atuator using smart material, rehabilization robot and active damping control. He is a member of IEEE, ASME, SICE, RSJ, JSME, KSME, KSPE, KSAE, KFPS, and JFPS. Bao Kha Nguyen received the B. S. and M. S. degree from Hochiminh City University of Technology in 2001 and 2003, respectively, all in Automatic Control Engineering and the Ph.D. degree from University of Ulsan in 2006. His research interests focus on intelligent control, modern control theory and their applications, design and control of smart actuator systems. WooKeun Jo received the B.S. degree in the department of Mechanical and Automotive Engineering from University of Ulsan in 2007. And he matriculated M.S. at University of Ulsan. Currently, he’s syudying on it. His research interests focus on fluid control, welfare vehicle, mobile robot     

Prediction of fatigue life distribution of marine propeller materials

Engineering materials have been studied and developed for a remarkably long time, but there are few reports about marine propeller materials. Recently, some researchers have studied the material strength of marine propellers. However, studies on parametric sensitivity and probabilistic distribution of fatigue life of propeller materials have not yet been carried out. In this study, we have evaluated strength characteristics of AlBC3 and HBsC1, both of which have been used for marine propellers using air jet chisel. Then a method to predict the probabilistic distributions of fatigue life of propeller materials is presented and the influence of several parameters on the life distribution is discussed. This paper was recommended for publication in revised form by Associate Editor Jooho Choi Han-Yong Yoon received his B.S. degree in Mechanical Engineering from DanKook University in Seoul, Korea, in 1981. He then received his M.S. and Ph.D. degrees from The University of Tokyo in Tokyo, Japan in 1985 and 1988, respectively. Dr. Yoon is currently a Professor at the Department of Mechanical Engineering at Mokpo National University in Jeonnam, Korea. And, he serves concurrently as the director of Library at his University. His research interests include reliability, fatigue, and fracture mechanics. Jianwei Zhang received his B.E. degree from the School of Electro-Mechanical Automobile Engineering from Yantai University, China, in 2005. He then received his M.E. from the Department of Mechanical Engineering Graduate School of Mokpo National University, Korea, in 2008. Mr. Zhang is currently studying for his doctorate at the Department of Mechanical Engineering, Graduate School of Mokpo National University, Jeonnam, Korea. His research interests include metal fatigue, weld residual stress, and composite materials fatigue.     

The articulated vehicle dynamic analysis using the AWS (All Wheel Steering) ECU (Electronic Control Unit) test

An AWS (all-wheel-steering) system is applied to the articulated vehicle to satisfy the required steering performance. AWS ECU (electronic control unit) controls the hydraulic actuator according to vehicle driving environment, such as driver steering angle, articulating angle, and vehicle velocity. In this paper, the test platform devloped for the AWS ECU black box test in an HIL( hardware in the loop) environment is explained. Using the developed test platform, the control algorithm of the AWS ECU can be evaluated under the virtual driving condition of the articulated vehicle. Also, the maneuver of the vehicle is investigated by using the developed AWS ECU test. This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korea, August 20–23, 2008. Sooho Lee received a B.S. degree in Mechanical Engineering from Ajou University in 2003. He then went on to receive his M.S. degree from Ajou University in 2005. Mr. Lee is currently a Ph.D student in the School of Mechanical Engineering at Ajou University in Suwon, Korea. His research interests are in the area of dynamics, vehicle dynamics, control and HILS ( hardware in the loop simulation).     

Optimization of the industrial guide-way vehicle to improve the running stability

This paper presents an optimization of the industrial guide-way vehicle that aims to improve running stability at increased speeds. A guide-way vehicle was used to transfer products in various manufacturing industries. Using Design Of Experiment(D.O.E.), the design prototype was optimized. The improved design prototype and its design parameters were obtained by a case study determined by the engineering discussion. The computational model for the optimization was validated by correlation with the test results. Through this procedure, the optimization method presented in this paper has been proven to be effective. This paper was presented at the 4th Asian Conference on Multibody Dynamics(ACMD2008), Jeju, Korea, August 20–23, 2008. Kab-Jin Jun received a B.S. degree in Mechanical Engineering from Ajou University in 2005. He is currently a Ph.D candidate at Ajou University in Suwon, Korea. His research interests are in the area of optimization, vehicle dynamics. Tae Won Park received a B.S. degree in Mechanical Engineering from Seoul University. He then went on to receive his M.S. and Ph.D. degrees from the University of Iowa. Dr. Park is currently a Professor at the School of Mechanical Engineering at Ajou University in Suwon, Korea. Sung Pil Jung is currently a Ph.D candidate at Ajou University in Suwon, Korea. Mr. Jung’s research interests are in the area of multi-body & structural dynamics, optimization and computer aided engineering.     

The effect of nonequilibrium condensation on hysteresis phenomenon of under-expanded jets

Under-expanded jets which are discharged from an orifice or a nozzle have long been subject of researches for aeronautical and mechanical applications. Provided that the jet pressure ratio and nozzle configuration are known, the major features of the steady jet are now well known. However, the jet pressure ratio is often varied even during the process in many practical applications. Many questions remain unanswered with regard to how the supersonic jet responds to the transient process of the pressure ratio and whether the steady jet data for a specific pressure ratio can still bear the same during the transient process of pressure ratio. In the present study, the hysteric phenomenon of under-expanded jets has been investigated with the help of computational fluid dynamics methods. The under-expanded jets of both dry and moist air have been employed to investigate the transient processes of the pressure ratio. The effects of nonequilibrium condensation occurring in the under-expanded moist air jets are explored on the hysteresis phenomenon. It is known that under-expanded air jet produced during the startup transient of jet behaves differently from the shutdown transient process, leading to the hysteric phenomenon of under-expanded jet. It is also known that the moist air jet reduces the hysteric phenomenon, compared with the dry air jet, and that non-equilibrium condensation which occurs in the underexpanded moist air jet is responsible for these findings. This paper was recommended for publication in revised form by Associate Editor Do Hyung Lee Heuy-Dong Kim received his B.S. and M.S. degrees in Mechanical Engineering from Kyungpook National University, Korea, in 1986 and 1988, respectively. He then received his Ph.D. degree from Kyushu University, Japan, in 1991. Dr. Kim is currently a Professor at the School of Mechanical Engineering, Andong National University, Korea. His research interests include High-Speed Trains, Ramiet and Scramiet, Shock Tube and Technology, Shock Wave Dynamics, Explosions & Blast Waves, Flow Measurement, Aerodynamic Noises and Supersonic Wind Tunnels. Min-Sung Kang received his B.S. and M.S degrees in Mechanical Engineering from Andong National University, Korea, in 2007 and 2009, respectively. Mr. Kang is currently a researcher at the School of Mechanical Engineering at Andong National University, Korea. His research interests include cavity and supersonic nozzle flows. Yumiko Otobe received her B.S. degree in Faculty of Engineering from Yamaguchi University, Japan, in 1978. She then received her Eng. D. degree from Saga University, Japan, in 2007. Dr. Otobe is currently a Research Associate at the Department of Control & Information Systems Engineering, Kitakyushu National College of Technology, Japan. Dr. Otobe’s research interests include sonic and supersonic jets of various gases as well as nonequilibrium condensation phenomena. Toshiaki Setoguchi received his B.S. degree in Mechanical Engineering from Tokyo University of Agriculture and Technology, Japan, in 1976. He then received his M.S. and Ph.D. degrees from Kyushu University, Japan, in 1978 and 1981, respectively. Dr. Setoguchi is currently a Professor at the Department of Mechanical Engineering, Saga University, Japan. His research interests include Nonequilibrium Condensation, Ramiet and Scramiet, Shock Tube and Technology, Shock Wave Dynamics, Explosions & Blast Waves, Aerodynamic Noises and Turbomachinery.