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Dr. Lung-Wen Tsai 1945–2002

Dr. Lung-Wen Tsai, the former technical editor of this journal passed away unexpectedly but peacefully due to a stroke at his home in Riverside, California, on Friday, November 29, 2002. He was a professor of mechanical engineering at the University of California (UC), Riverside. His loving wife Lung-Chu, daughter Jule Ann, and son David survive him.

Dr. Tsai was born in Taipei, Taiwan, on February 20, 1945, and was the youngest of 10 siblings. A hard worker, Dr. Tsai helped cultivate his family’s farm until he finished his undergraduate studies in mechanical engineering at the National Taiwan University in 1967. He then came to this country and studied mechanical engineering at State University of New York at Buffalo receiving his M.S. degree in 1970. He then went to California and attended Stanford University receiving his Ph.D. in mechanical engineering in 1973. He was the only sibling in his family to leave Taiwan and study in the United States.

Before joining the Bourns College of Engineering faculty at UC Riverside in 2000, Dr. Tsai was a professor at the University of Maryland in College Park for over fourteen years where he established world-renowned research and educational programs in robotics and mechanisms, and had been a research engineer with the General Motors Corporation and Hewlett-Packard Company.

Dr. Tsai’s research interests were in kinematics, robotics, mechanisms and machine theory, and mechanical design. Dr. Tsai has made several important contributions to these fields starting with his Ph.D. thesis where he developed geometric conditions for studying “incompletely specified displacements.” He then applied this to the design of three-dimensional linkages. The work still remains as a key contribution to kinematics and machine theory. It has also found applications in robotics and trajectory planning.

In robotics, he was the first to numerically determine all the real solutions of the most general kinematic equations for six and five degrees of freedom serial robot manipulators. Dr. Tsai has also made several contributions on design of robotic systems which includes design of geared and tendon driven devices and parallel manipulators and platforms. His most recent contribution in this area has been the development of a novel parallel manipulator at UC Riverside. This manipulator is unique in that it uses a parallel articulated and over-constrained kinematic structure but behaves like a conventional X-Y-Z gantry system. Some of his other contributions in mechanical design include his work on design of geared transmission devices, his novel design and analysis of a harmonic balancer, and his work on Oldham Couplings for automotive applications.

Dr. Tsai was a Fellow of the American Society of Mechanical Engineers and a member of the Society of Automotive Engineers. He held numerous U.S. patents and was the author of two textbooks, 66 archival journal or transactions papers, and 100 conference and other papers that have been published up to the time of this memorial. His honors include the ASME Melville Medal received in 1985, Best Paper Awards (1984 ASME Mechanisms Conference, 1989 and 1991 Applied Mechanisms and Robotics Conference), Arch Colwell Merit Award (1988 SAE International Congress & Exposition), South Pointing Chariot Award (1993 Applied Mechanisms & Robotics Conference), Presidential Chair Professor at UC Riverside (2000–2002), and numerous international invited professorships and lectureships. In February 2002, Dr. Tsai was elected as an Honorary Professor at National Chiao-Tung University, one of the top five universities in Taiwan. In September 2002, Dr. Tsai was elected as a Fellow of the American Association for the Advancement of Science (AAAS), which publishes the peer-reviewed journal Science.

Dr. Tsai’s professional activities included serving both as a member and the chair of the mechanisms technical committee within the design division of ASME, general chair of the International Design Engineering Technical Conferences in 2000 and serving as the Technical Editor of the ASME Journal of Mechanical Design, since 1998.

Dr. Tsai was a dedicated educator and a scholar, respected by his students and fellow colleagues. He was also devoted to his family, friends, and his profession. He will be missed by those who knew him as well as by the scientific and engineering communities. Following this memorial is a list of Dr. Tsai’s technical publications.

Books

Tsai, L. W., 2000, Mechanism Design: Enumeration of Kinematic Structures According to Function, CRC Press, Boca Raton, FL.

Tsai, L. W., 1999, Robot Analysis: The Mechanics of Serial and Parallel Manipulators, John Wiley & Sons, New York, N.Y.

Papers in Archival Journals and Transactions

Fang, Y., and Tsai, L. W., 2003, “Inverse Velocity and Singularity Analysis of Low-DOF Serial Manipulators,” Journal of Robotic Systems, Vol. 20, No. 4, pp. 177–188.

Fang, Y., and Tsai, L. W., 2003, “Feasible Motion Solutions for Serial Manipulators at Singular Configurations,” ASME Journal of Mechanical Design, Vol. 125, No. 1, pp. 61–69.

Kim, H. S., and Tsai, L. W., 2003, “Design Optimization of a Cartesian Parallel Manipulator,” ASME Journal of Mechanical Design, Vol. 125, No. 1, pp. 43–51.

Joshi, S., and Tsai, L. W., 2003, “The Kinematics of a Class of 3-DOF, 4-Legged Parallel Manipulators,” ASME Journal of Mechanical Design, Vol. 125, No. 1, pp. 52–60.

Joshi, S., and Tsai, L. W., 2003, “A Comparison Study of Two 3-DOF Parallel Manipulators: One with Three and the Other With Four Supporting Legs,” IEEE Transactions on Robotics and Automation, Vol. 19, No. 2, pp. 200–209.

Kim, H. S., and Tsai, L. W., 2003, “Kinematic Synthesis of a Spatial 3-RPS Parallel Manipulator,” ASME Journal of Mechanical Design, Vol. 125, No. 1, pp. 92–97.

Fang, Y., and Tsai, L. W., 2002, “Structure Synthesis of a Class of 4-DOF and 5-DOF Parallel Manipulators With Identical Limb Structures,” Journal of Robotic Systems, Vol. 21, No. 9, pp. 799–810.

Joshi, S., and Tsai, L. W., 2002, “Jacobian Analysis of Limited-DOF Parallel Manipulators,” ASME Journal of Mechanical Design, Vol. 124, No. 2, pp. 254–258.

Tsai, L. W., and Joshi, S., 2002, “Kinematic Analysis of 3-DOF Position Mechanisms for Use in Hybrid Kinematic Machines,” ASME Journal of Mechanical Design, Vol. 124, No. 2, pp. 245–253.

Lee, J. J., and Tsai, L. W., 2002, “Structural Synthesis of Multi-Fingered Hands,” ASME Journal of Mechanical Design, Vol. 124, No. 2, pp. 272–276.

Kimbal, C., and Tsai, L. W., 2002, “Modeling of Flexural Sections Subjected to Arbitrary End Loads,” ASME Journal of Mechanical Design, Vol. 124, No. 2, pp. 223–235.

Schultz, G. A., Tsai, L. W., Higuchi, N., and Tong, I. C., 2001, “Development of a Novel Parallel Hybrid Transmission,” SAE Transactions, Journal of Passenger Cars—Mechanical Systems, paper No. 2001-01-0875; also in SAE Special Publications on Transmission & Driveline Systems, SP-1598.

Tsai, L. W., Schultz, G., and Higuchi, N., 2001, “A Novel Parallel Hybrid Transmission,” ASME Journal of Mechanical Design, Vol. 123, No. 2, pp. 161–168.

Tsai, L. W., and Joshi, S., 2000, “Kinematics and Optimization of a Spatial 3-UPU Parallel Manipulator,” ASME Journal of Mechanical Design, Vol. 122, No. 4, pp. 439–446.

Tsai, L. W., 2000, “Solving the Inverse Dynamics of a Stewart-Gough Manipulator by the Principle of Virtual Work,” ASME Journal of Mechanical Design, Vol. 122, No. 1, pp. 3–9.

Hsieh, H. I., and Tsai, L. W., 1998, “The Selection of a Most Efficient Clutching Sequence Associated With an Automatic Transmission Mechanism,” ASME Journal of Mechanical Design, Vol. 120, No. 4, pp. 514–519.

Tsai, L. W., Chen, D. Z., and Lin, T. W., 1998, “Dynamic Analysis of Geared Robotic Mechanisms Using Graph Theory,” ASME Journal of Mechanical Design, Vol. 120, No. 2, pp. 240–244.

Shieh, W. B., Tsai, L. W., Azarm, S., and Tits, A., 1998, “A New Class of Six-Bar Mechanisms with Symmetrical Coupler Curves,” ASME Journal of Mechanical Design, Vol. 120, No. 1, pp. 150–153.

Shieh, W. B., Tsai, L. W., and Azarm, S., 1997, “Design and Optimization of a One-DOF Six-Bar Leg Mechanism for a Walking Machine,” Journal of Robotic Systems, Vol. 14, No. 12, pp. 871–880.

Hsieh, H. I., and Tsai, L. W., 1997, “A Methodology for Enumeration of Clutching Sequences Associated with Epicyclic-Type Automatic Transmission Mechanisms,” SAE Transactions, Journal of Passenger Cars, Sec. 6, Vol. 105, pp. 928–936.

Ou, Y. J., and Tsai, L. W., 1996, “Isotropic Design of Tendon-Driven Manipulators,” ASME Journal of Mechanical Design, Vol. 118, No. 3, pp. 360–366.

Chatterjee, G., and Tsai, L. W., 1996, “Computer Aided Sketching of Epicyclic-Type Automatic Transmission Gear Trains,” ASME Journal of Mechanical Design, Vol. 118, No. 3, pp. 405–411.

Hsieh, H. I., and Tsai, L. W., 1996, “Kinematic Analysis of Epicyclic-Type Transmission Mechanisms Using the Concept of Fundamental Geared Entities,” ASME Journal of Mechanical Design, Vol. 118, No. 2, pp. 294–299.

Shieh, W. B., Tsai, L. W., Azarm, S., and Tits, A. L., 1996, “Multiobjective Optimization of a Leg Mechanism With Various Spring Configurations for Force Reduction,” ASME Journal of Mechanical Design, Vol. 118, No. 2, pp. 179–185.

Tahmasebi, F., and Tsai, L. W., 1995, “On the Stiffness of a Novel Six-DOF Parallel Mini-manipulator,” Journal of Robotic Systems, Vol. 12, No. 12, pp. 845–856.

Tsai, L. W., 1995, “Design of Tendon-Driven Manipulators,” ASME Transactions, A Special Combined Issue of the ASME Journal of Mechanical Design and Journal of Vibration and Acoustics, Vol. 117(B), pp. 80–86.

Lee, J. J., and Tsai, L. W., 1995, “Dynamic Simulation of Tendon-Driven Manipulators,” Journal of Applied Mechanisms and Robotics, Vol. 2, No. 1, pp. 40–60.

Chatterjee, G., and Tsai, L. W., 1995, “Enumeration of Epicyclic-Type Automatic Transmission Gear Trains,” SAE Transactions, Journal of Passenger Cars, Sec. 6, Vol. 103, pp. 1415–1426.

Tsai, L. W., and Chang, S. L., 1994, “Backlash Control via Redundant Drives: An Experimental Verification,” ASME Journal of Mechanical Design, Vol. 116, No. 3, pp. 963–967.

Tahmasebi, F., and Tsai, L. W., 1994, “Closed-Form Direct Kinematics Solution of a New Parallel Mini-Manipulator,” ASME Journal of Mechanical Design, Vol. 116, No. 4, pp. 1141–1147.

Huang, F., Chen, R. J., and Tsai, L. W., 1994, “The Use of Random Steer Test Data for Vehicle Parameter Estimation,” SAE Transactions, Vol. 102, pp. 1329–1340.

Chen, D. Z., and Tsai, L. W., 1994, “Synthesis of Geared Robotic Mechanisms with Maximum Acceleration Capacity,” Journal of Applied Mechanisms and Robotics, Vol. 1, No. 3, pp. 17–25.

Tahmasebi, F., and Tsai, L. W., 1994, “Workspace and Singularity Analysis of a Novel Six-DOF Parallel Mini-Manipulator,” Journal of Applied Mechanisms and Robotics, Vol. 1, No. 2, pp. 31–40.

Ou, Y. J., and Tsai, L. W., 1993, “Kinematic Synthesis of Tendon-Driven Manipulators With Isotropic Transmission Characteristics,” ASME Journal of Mechanical Design, Vol. 115, No. 4, pp. 884–891.

Lee, J. J., and Tsai, L. W., 1993, “Torque Resolver Design for Tendon-Driven Manipulators,” ASME Journal of Mechanical Design, Vol. 115, No. 4, pp. 877–883.

Tsai, L. W., and Tahmasebi, F., 1993, “Synthesis and Analysis of a New Class of Six-DOF Parallel Mini-Manipulators,” Journal of Robotic Systems, Vol. 10, No. 5, pp. 561–580.

Chen, D. Z., and Tsai, L. W., 1993, “Kinematic and Dynamic Synthesis of Geared Robotic Mechanisms,” ASME Transactions, Journal of Mechanical Design, Vol. 115, No. 2, pp. 241–246.

Chang, S. L., and Tsai, L. W., 1993, “On the Redundant-Drive Backlash-Free Robotic Mechanisms,” ASME Transactions, Journal of Mechanical Design, Vol. 115, No. 2, pp. 247–254.

Lin, C. C., and Tsai, L. W., 1993, “The Trajectory Analysis of Bevel Planetary Gear Trains,” ASME Journal of Mechanical Design, Vol. 115, No. 1, pp. 164–170.

Lee, J. J., and Tsai, L. W., 1991, “On the Structural Synthesis of Tendon-Driven Manipulators Having Pseudo-Triangular Structure Matrix,” International Journal of Robotics Research, Vol. 10, No. 3, pp. 255–262.

Tsai, L. W., and Lu, J. J., 1990, “Coupler-Point-Curve Synthesis using Homotopy Methods,” ASME Journal of Mechanical Design, Vol. 112, No. 3, pp. 384–389.

Chang, S. L., and Tsai, L. W., 1990, “Topological Synthesis of Articulated Gear Mechanisms,” IEEE Transactions on Robotics and Automation, Vol. 6, No. 1, pp. 97–103.

Azarm, S., Chen, R., and Tsai, L. W., 1990, “Walking Robot: A Multidisciplinary Design Project for Undergraduate Students,” International Journal of Mechanical Engineering Education, Vol. 18, No. 2, pp. 101–115.

Tsai, L. W., and Lin, C. C., 1989, “The Creation of Non-fractionated, Two Degree-of-Freedom Epicyclic Gear Trains,” ASME Journal of Mechanisms, Transmissions, and Automation in Design, Vol. 111, No. 4, pp. 524–529.

Tsai, L. W., and Maki, E. R., 1989, “Planetary-Gear-Type Second-Harmonic Balancers,” ASME Journal of Mechanisms, Transmissions, and Automation in Design, Vol. 111, No. 4, pp. 530–536.

Freudenstein, F., Tsai, L. W., and Maki, E. R., 1989, “The Synthesis and Analysis of Variable-Valve-Timing Mechanisms for Internal-Combustion Engines,” SAE Transactions, Vol. 97, pp. 6.642–6.651.

Tsai, L. W., and Freudenstein, F., 1989, “On the Conceptual Design of a Novel Class of Robot Configurations,” ASME Journal of Mechanisms, Transmissions, and Automation in Design, Vol. 111, No. 1, pp. 47–53.

Tsai, L. W., and Lee, J. J., 1989, “Kinematic Analysis of Tendon-Driven Robotic Mechanisms using Graph Theory,” ASME Journal of Mechanisms, Transmissions, and Automation in Design, Vol. 111, No. 1, pp. 59–65.

Tsai, L. W., Maki, E. R., and Jacques, R. C., 1988, “Evaluation of the Oldham-Coupling-Type Balancer on a 90-degree V-6 Engine,” SAE Transactions, Vol. 96, pp. 4.10–4.15.

Tsai, L. W., 1988, “The Kinematics of Spatial Robotic Bevel-Gear Trains,” IEEE Transactions on Robotics and Automation, Vol. 4, No. 2, pp. 150–156.

Tsai, L. W., 1987, “Discussion—On the Maximum Value of the Maximum Degree of Kinematic Chain,” ASME Journal of Mechanisms, Transmissions, and Automation in Design, Vol. 109, No. 4, p. 490.

Tsai, L. W., 1987, “An Application of Linkage Characteristic Polynomial to the Topological Synthesis of Epicyclic Gear Trains,” ASME Journal of Mechanisms, Transmissions, and Automation in Design, Vol. 109, No. 3, pp. 329–336.

Tsai, L. W., and Morgan, A. P., 1985, “Solving the Kinematics of the Most General Six- and Five-Degree-of-Freedom Manipulators by Continuation Methods,” ASME Journal of Mechanisms, Transmissions, and Automation in Design, Vol. 107, No. 2, pp. 189–200.

Tsai, L. W., and Walter, R., 1985, “Evaluation of the Oldham-Coupling Type Balancer on a 2.5 Liter In-line Four-Cylinder Engine,” SAE Transactions, Vol. 93, Paper No. 840456, pp. 3.378–3.382.

Freudenstein, F., Tsai, L. W., and Maki, E. R., 1984, “The Generalized Oldham Coupling,” ASME Journal of Mechanisms, Transmissions, and Automation in Design, Vol. 106, No. 4, pp. 475–481.

Tsai, L. W., 1984, “Oldham Coupling Second-Harmonic Balancer,” ASME Journal of Mechanisms, Transmissions, and Automation in Design, Vol. 106, No. 3, pp. 285–290.

Tsai, L. W., 1983, “Design of Drag-Link Mechanisms with Minimax Transmission Angle Deviation,” ASME Journal of Mechanisms, Transmissions, and Automation in Design, Vol. 105, No. 4, pp. 686–691.

Tsai, L. W., 1983, “Design of Drag-Link Mechanisms with Optimum Transmission Angle,” ASME Journal of Mechanisms, Transmissions, and Automation in Design, Vol. 105, No. 2, pp. 254–258.

Tsai, L. W., 1982, “Kinematic Synthesis of an Adjustable Six-Bar Angular Motion Compensator,” ASME Journal of Mechanical Design, Vol. 104, No. 1, pp. 21–28.

Tsai, L. W., and Ciardella, R. L., 1979, “Linear Step Motor Design Provides High Plotter Performance at Low Cost,” Hewlett-Packard Journal, pp. 7–14.

Tsai, L. W., 1977, “Instantaneous Kinematics of a Special Two-Parameter Motion,” ASME Journal of Engineering for Industry, Vol. 99, Series B, No. 1, pp. 336–340.

Tsai, L. W., and Roth, B., 1973, “A Note on the Design of Revolute-Revolute Cranks,” Journal of Mechanism and Machine Theory, Vol. 8, pp. 23–31.

Tsai, L. W., and Roth, B., 1973, “Incompletely Specified Displacement: Geometry and Spatial Linkage Synthesis,” ASME Journal of Engineering for Industry, Vol. 95, Series B, No. 2, pp. 603–611.

Tsai, L. W., and Roth, B., 1972, “Design of Dyads with Helical, Cylindrical, Spherical, Revolute, and Prismatic Joints,” Journal of Mechanism and Machine Theory, Vol. 7, No. 1, pp. 85–102.

Reismann, H., and Tsai, L. W., 1972, “Forced Motion in Elastic Cylindrical Rods—A Comparison of Two Theories,” Zeitschrift fur Angewandte Mathematik & Mechanik, Vol. 52, pp. 565–572.

Reismann, H., and Tsai, L. W., 1972, “Wave Propagation in Discretely Inhomogeneous Elastic Cylindrical Rods—A Comparison of Two Theories,” Zeitschrift fur Angewandte Mathematik & Mechanik, Vol. 52, pp. 1–10.