[1] M. Iwasaki, K. Seki, and Y. Maeda, “High-Precision Motion Control Techniques: A Promising Approach to Improving Motion PerformanceIEEE Industrial Electronics Magazine, Vol.6, No. l,pp. 32-40, 2012.
[2] T. Oomen, “Advanced Motion Control for Precision Mechatronics: Control, Identification, and Learning of Complex Systems,” IEEJ Journal of Industry Applications, Vol.7, No. 2, pp.127- 140, 2018.
[3] T. Yamaguchi, M. Hirata, and H. Fujimoto, “Nanoscale Servo Control,Tokyo Denki University Press, 2007 (in Japanese).
[4] G. F. Franklin, J. D. Powell, and M. L. Workman, "Digital Control of Dynamic Systems Third Edition,Addison-Wesley, 1998.
[5] S. A. Napper and R. L. Seaman, 'Applications of Robots in Rehabilitation, ” Robotics and Autonomous Systems, vol.5, no. 3, pp. 227-239, 1989.
[6] R. Lu, Z. Li, C. Su, and A. Xue, "Development and learning control of a human limb with a rehabilitation exoskeleton, ’’ IEEE Transactions on Industrial Electronics, vol.61,no. 7, pp. 3776-3785, 2014.
[7] R. H. Taylor and D. Stoianovici, “Medical robotics in computer-integrated surgery, ” IEEE Transactions on Robotics and Automation, vol.19, no. 5, pp. 765-781, 2003.
[8] J. Burgner, D. C. Rucker, Η. B. Gilbert, P. J. Swaney, P. T. Russell,K. D. Weaver, and R. J. Web ster, “A Telerobotic System for Transnasal Surgery, ” 1EEE/ASME Transactions on Mechatron- ics, Vol.19, No. 3, pp. 996-1006, 2014.
[9] S. Haddadin, A. De Luca, and A. Albu-Schaffer, “Robot collisions: A survey on detection, isolation, and identification, ” IEEE Transactions on Robotics, vol.33, no. 6, pp. 1292-1312, 2017.
[10] Z. Li, J. Liu, Z. Huang, Y Peng, H. Pu, and L. Ding, ‘"Adaptive Impedance Control of Human- Robot Cooperation Using Reinforcement Learning, ’’ IEEE Transactions on Industrial Electron ics. vol.64, no.10, pp. 8013-8022, 2017.
[11] K. Cleary, A. Melzer, V. Watson, G. Kronreif and D. Stoianovici, "Interventional Robotic Sys tems: Applications and Technology State-of-the-Art,” Minim. Invasive Ther. Allied Technol, Vol. 15, pp. 101-113, 2006.
[12] G. S. Guthart and J. K. Salisbury, “The Intuitive Telesurgery System: Overview and Applica tion,Proceedings of IEEE International Conference on Robotics and Automation ICRA ’00, pp. 618-621, April 24-28, 2000.
[13] A. Sabanovic, "Challenges in Motion Control Systems,’’ IEEJ Journal of Industry Applications, Vol.6, No. 2, pp. 107-116, 2017.
[14] K. Kosuge, “Force Control of Manipulators,9, Journal of the Robotics Society of Japan, Vol.9, No. 6, pp. 751-758, 1991 (in Japanese).
[15] N. Yamanobe, "Research Trends of Force Control in Robotic Manipulation,Journal of the Society of Instrument and Control Engineers. Vol.56, No.10, pp. 741-746, 2017 (in Japanese).
[16] N. Hogan, “Impedance Control: An Approach to Manipulation: Part I, II, and 111,’’ Transaction of the ASMEf Journal of Dynamic Systems, Measurement, and Control, Vol. 107, No.1,pp. 1-24, 1985.
[17] W. He and Y. Dong, ''Adaptive Fuzzy Neural Network Control for a Constrained Robot Using Impedance Learning,” IEEE Transactions on Neural Networks and Learning Systems, Vol.29, No. 4, pp. 1174-1186, 2018.
[18] K. Kronander and A. Billard, "Stability Considerations for Variable Impedance ControlIEEE Transactions on Robotics. Vol.32, No. 5, pp. 1298-1305, 2016.
[19] G. A. Pratt and Μ. M. Williamson, “Series elastic actuators,” in Proceedings of1995IEEE/RSJ International Conference on Intelligent Robots and Systems, vol.1,pp. 399-406, 1995.
[20] O. Khatib, “A Unified Approach for Motion and Force Control of Robot Manipulators: The Operational Space Formulation,9, IEEE Journal of Robotics and Automation. Vol.3, No.1,pp. 43-53, 1987.
[21] K. Ohnishi, M. Shibata, and T. Murakami, “Motion Control for Advanced Mechatronics,” IEEE/ASME Transactions on Mechatronics, Vol.1,No.1,pp. 56-67, 1996.
[22] S. Katsura, Y Matsumoto, and K. Ohnishi, “Modeling of Force Sensing and Validation of Dis turbance Observer for Force Control, M IEEE Transactions on Industrial Electronics, Vol.54, No. l,pp. 530-538, 2007.
[23] X. C. Ma, G. Q. He, D. H. He, C. S. Chen, and Z. F. Hu, “Sliding Wear Behavior of Copper- Graphite Composite Material for Use in Maglev Transportation System:’ Wear, Vol. 265, No. 7-8, pp.1087-1092, 2008.
[24] D. H. He, R. R. Manory, and N. Grady, “Wear of Railway Contact Wires against Current Col lector Materials,Wear, Vol. 215, No. 1-2, pp. 146-155, 1998.
[25] T. Sata, “Thermal Characteristics of Metal Wear,^^ Transactions of the Japan Society of Meehan- ical Engineers, Vol.25, No.151,pp. 227-234, 1959 (in Japanese).
[26] M. Mizuno, “Correlation between Metal Wear and Friction under Unlubricated Condition, Journal of the Japan Society of Precision Engineering, Vol.27, No. 318, pp. 462-467, 1961 (in Japanese).
[27] M. Mizuno, "Correlation between Metal Wear and Friction under Boundary Lubrication, Journal of the Japan Society of Precision Engineering, Vol.28, No. 324, pp. 12-17, 1962 (in Japanese).
[28] C. Yamashita and K. Adachi, "Influence of Current on Wear Modes and Transition Condition of Current Collecting Materials, Journal of Japanese Society of Tribologists, Vol.58, No. 7, pp. 496-503, 2013 (in Japanese).
[29] H. Nagasawa and K. Kato, “Wear Mechanism of Copper Alloy Wire Sliding against Iron-Base Strip under Electric Current, Wear, Vol. 216, No. 2, pp. 179-183, 1998.
[30] Y. Kubota, S. Nagasaka, T. Miyauchi, C. Yamashita, and H. Kakishima, “Sliding Wear Behavior of Copper Alloy Impregnated C/C Composites under an Electrical Current, Wear, Vol. 302, No. 1-2, pp. 1492-1498, 2013.
[31] S. F. Moustafa, S. A. El-Badry, A. M. Sanad, and B. Kieback, “Friction and Wear of Copper- Graphite Composites Made with Cu-Coated and Uncoated Graphite Powders,” Wear, Vol. 253, No. 7-8, pp. 699-710, 2002.
[32] G. X. Chen, F. X. Li, L. Dong, Μ. H. Zhu, and Z. R. Zhou, “Friction and Wear Behaviour of Stainless Steel Rubbing against Copper-Impregnated Metallized Carbon,5, Tribology Interna· tional, Vol.42, No. 6, pp. 934-939, 2009.
[33] T. Ding, G. X. Chen, X. Wang, Μ. H. Zhu, W. H. Zhang, and W. X. Zhou, “Friction and Wear Behavior of Pure Carbon Strip Sliding against Copper Contact Wire under AC Passage at High Speeds,” Tribology International, Vol.44, No. 4, pp. 437444, 2011.
[34] H. J. Yang, G. X. Chen, G. Q. Gao, G. N. Wu, and W. H. Zhang, "Experimental Research on the Friction and Wear Properties of a Contact Strip of a Pantograph-Catenary System at the Sliding Speed of 350 km/h with Electric Current, M Wear, Vol. 332-333, pp. 949-955, 2015.
[35] S. C. Lim and M. F. Ashby, 'Overview No. 55 Wear-Mechanism Maps,” Acta Metallurgical Vol. 35, No.1,pp. 1-24, 1987.
[36] A. Sabanovic and K. Ohnishi, “Motion Control Systems,M John Wiley & Sons. 2011.
[37] E. Sariyildiz and K. Ohnishi, “On the Explicit Robust Force Control via Disturbance Observer, IEEE Transactions on Industrial Electronics. Vol.62, No. 3, pp. 1581-1589, 2015.
[38] S. Oh and K. Kong, "High-Precision Robust Force Control of a Series Elastic Actuator,” IEEE/ASME Transactions on Mechatronics. Vol.22, No.1,pp. 71-80, 2017.
[39] A. Calanca and R Fiorini, "Understanding Environment-Adaptive Force Control of Series Elas tic Actuators,IEEE/ASME Transactions on Mechatronics. Vol. 23, No.1,pp. 413^423, 2018.
[40] X. Zhang and Μ. B. Khamesee, 'Adaptive Force Tracking Control of a Magnetically Navigated Microrobot in Uncertain Environment,IEEE/ASME Transactions on Mechatronics. Vol.22, No. 4, pp. 1644-1651,2017.
[41] T. Murakami, F. Yu, and K. Ohnishi, “Torque Sensorless Control in Multidegree-of-Freedom Manipulator,IEEE Transactions on Industrial Electronics. Vol.40, No. 2, pp. 259-265, 1993.
[42] S. Fujihara, K. Seki, and M. Iwasaki, ''Experimental Evaluations of Force Control Using Re action Force Observer Considering Friction Dynamics,in Proceedings of I EE J International Workshop on Sensing, Actuation, Motion Control, and Optimization (SAMCON2016). V-10, 2 pages, 2016.
[43] T. T. Phuong, R. Furusawa, M. Nandayapa, C. Mitsantisuk, and K. Ohishi, “FPGA-Based Wide band Force Control System with Friction-Free and Noise-Free Force Observation,IEEJ Journal of Industry Applications. Vol.1,No. 3, pp. 178-190, 2012.
[44] E. Sariyildiz and K. Ohnishi, “An Adaptive Reaction Force Observer Design, IEEE/ASME Transactions on Mechatronics. Vol.20, No. 2, pp. 750-760, 2015.
[45] S. Katsura, K. Irie, and K. Ohishi, "Wideband Force Control by Position-Acceleration Integrated Disturbance Observer, IEEE Transactions on Industrial Electronics. Vol.55, No. 4, pp. 1699- 1706, 2008.
[46] C. Mitsantisuk, K. Ohishi, and S. Katsura, "Estimation of Action/Reaction Forces for the Bilateral Control Using Kalman Filter, IEEE Transactions on Industrial Electronics, Vol.59, No. 11,pp. 4383-4393, 2012.
[47] R. E. Kalman, “A New Approach to Linear Filtering and Prediction Problems,99 Transactions of ASMEf Series D, Journal of Basic Engineering, Vol.82, No.1,pp. 35-45,1960.
[48] K. Szabat and T. Orlowska-Kowalska, "Vibration Suppression in a Two-Mass Drive System Using PI Speed Controller and Additional Feedbacks-Comparative Study:’ IEEE Transactions on Industrial Electronics, Vol.54, No. 2, pp.1193-1206, 2007.
[49] H. Yu, S. Huang, G. Chen, Y. Pan, and Z. Guo, "Human-robot interaction control of rehabilitation robots with series elastic actuators, M IEEE Transactions on Robotics, vol.31,no. 5, pp. 1089-1100, 2015.
[50] T. Boaventura and J. Buchli, ‘"Acceleration-based transparency control framework for wearable robots, ” in Proceedings of 2016IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pp. 5683-5688, 2016.
[51] J. Bae, K. Kong, and M. Tomizuka, “Gait phase-based smoothed sliding mode control for a rotary series elastic actuator installed on the knee joint, ” in Proceedings of the 2010 American Control Conference, pp. 6030-6035, 2010.
[52] T. Zhang, M. Tran, and H. Huang, 'Admittance shaping-based assistive control of sea-driven robotic hip exoskeleton, ” IEEE/ASME Transactions on Mechatronics, vol.24, no. 4, pp. 1508- 1519, Aug. 2019.
[53] E. Sariyildiz, G. Chen, and H. Yu, “An acceleration-based robust motion controller design for a novel series elastic actuator, ” IEEE Transactions on Industrial Electronics, vol.63, no. 3, pp. 1900-1910, 2016.
[54] S. Katsura and K. Ohnishi, “Force servoing by flexible manipulator based on resonance ratio control,” IEEE Transactions on Industrial Electronics, vol.54, no.1,pp. 539-547, 2007.
[55] Y. Park, N. Paine, and S. Oh, ''Development of force observer in series elastic actuator for dynamic control, IEEE Transactions on Industrial Electronics, vol. 65, no. 3, pp. 2398-2407, 2018.
[56] C. Mitsantisuk, M. Nandayapa, K. Ohishi, and S. Katsura, “Design for sensorless force control of flexible robot by using resonance ratio control based on coefficient diagram method, ’’ Automatika, vol.54, no.1,pp. 62-73, 2013.
[57] S. Yamada and H. Fujimoto, "Minimum variance estimation of load-side external torque using load-side encoder and torque sensor, ” in Proceedings of the 2018 57th Annual Conference of the Society of Instrument and Control Engineers of Japan (SICE), pp. 737-742, 2018.
[58] T. Kai, H. Sekiguchi, and H. Ikeda, "Relative Vibration Suppression in a Positioning Machine Using Acceleration Feedback Control,IEEJ Journal of Industry Applications. Vol.7, No.1, pp. 15-21,2018.
[59] Y. Yoshiura and Y. Kaku, “Vibration Suppression Control by Acceleration Sensofs Feedback, IEEJ Transactions on Industry Applications. Vol. 134, No. 9, pp. 801-806, 2014 (in Japanese).
[60] A. Jinzenji, T. Sasamoto, K. Aikawa, S. Yoshida, and K. A ruga, ''Acceleration Feedforward Control Against Rotational Disturbance in Hard Disk Drives,’’ IEEE Transactions on Magnetics. Vol.37, No. 2, pp. 888-893, 2001.
[61] K. Seki and M. Iwasaki, "Disturbance Suppression Control Combined Disturbance Observer with Acceleration Feedback in 2-Dimensional Shaking Table System,Proceedings of the 2014 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM), pp. 156- 161, July 8-11,2014.
[62] W. Shang and S. Cong, “Motion Control of Parallel Manipulators Using Acceleration Feed back, IEEE Transactions on Control Systems Technology, Vol.22, No.1,pp. 314—321, 2014.
[63] W. L. Xu, J. D. Han, and S. K. Tso, "Experimental Study of Contact Transition Control Incorporating Joint Acceleration Feedback, M IEEE/ASME Transactions on Mechatronics,Vol.5, No. 3, pp. 292-301,200〇.
[64] P. B. Schmidt and R. D. Lorenz, “Design Principles and Implementation of Acceleration Feed back to Improve Performance of DC Drives,,? IEEE Transactions on Industry Applications. Vol. 28, No. 3, pp. 594^599, 1992.
[65] Y. Yokokura, K. Ohishi, and S. Katsura, “Fine Force Reproduction Based on Motion-Copying System Using Acceleration Observer,,9 IEEE Transactions on Industrial Electronics, Vol.61, No.11,pp. 6213-6221,2014.
[66] A. Calanca and P Fiorini, “A rationale for acceleration feedback in force control of series elastic actuators, ’’ IEEE Transactions on Robotics, vol.34, no.1,pp. 48-61, 2018.
[67] S. Nagai, R. Oboe, T. Shimono, and A. Kawamura, “Fast Force Control without Force Sensor Using Combination of aaKF and RFOB for In-circuit Test with Probing System, IEEJ Journal of Industry Applications, Vol.8, No. 2, pp. 152-159, 2019.
[68] D. Cheon and S. Oh, ''Acceleration based force estimation in series elastic actuator,” in Proceedings of the IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society, pp. 5062-5067, 2018.
[69] M. Yokoyama, R. Oboe, and T. Shimono, “Robustness analysis of two-mass system control using acceleration-aided kalmanfilter, ” in Proceedings of the IECON 2018 - 44th Annual Con ference of the IEEE Industrial Electronics Society, pp. 4600-4605, 2018.
[70] R. Antonello, K. Ito, and R. Oboe, "Acceleration Measurement Drift Rejection in Motion Control Systems by Augmented-State Kinematic Kalman Filter, IEEE Transactions on Industrial Electronics, Vol.63, No. 3, pp. 1953-1961, 2016.
[71] T. T. Phuong, K. Ohishi, C. Mitsantisuk, Y. Yokokura, K. Ohnishi, R. Oboe, and A. Sabanovic, “Disturbance Observer and Kalman Filter Based Motion Control Realization,” IEEJ Journal of Industry Applications. Vol. 7, No.1,pp. 1-14, 2018.
[72] T. Yoshioka, T. T. Phuong, A. Yabuki, K. Ohishi, T. Miyazaki, and Y. Yokokura, “High- performance Load Torque Compensation of Industrial Robot using Kalman-filter-based Instan-taneous State Observer,” IEEJ Journal of Industry Applications. Vol.4, No. 5, pp. 589-590, 2015.
[73] A. Yabuki, K. Ohishi, T. Miyazaki, and Y. Yokokura, “Force Control Including Contact Process Using Acceleration-sensor-based Instantaneous State Observer for High-Stiffness Gear Drive,” in Proceedings of 2016 IEEE 25th International Symposium on Industrial Electronics, pp. 651- 656, 2016.
[74] N. Kobayashi and T. Murakami, "Comparison of Force Control Performance Based on Only Acceleration Sensor with KF/EKF,” IEEJ Journal of Industry Applications. Vol.4, No. 5, pp. 559-567, 2015.
[75] E. A. Baran, T. Uzunovic, and A. Sabanovic, ''Performance Improvement of Bilateral Control Systems Using Derivative of Force:’ Robotica, Vol.36, No.11,pp. 1627-1640, 2018.
[76] K. H. Ang, G. Chong, and Y. Li, “PID Control System Analysis, Design, and Technology,” IEEE Transactions on Control Systems Technology, Vol.13, No. 4, pp. 559-576, 2005.
[77] Y. Nagatsu and S. Katsura, “High-Order Disturbance Estimation Using Kalman Filter for Precise Reaction-Torque Control, in Proceedings of 2016 IEEE 14th International Workshop on Advanced Motion Control, pp. 79-84, 2016.
[78] R. Schindeler and K. Hashtrudi-Zaad, 'Online Identification of Environment Hunt-Crossley Models Using Polynomial Linearization, 9 IEEE Transactions on Robotics. Vol.34, No. 2, pp. 447458, 2018.
[79] H. Kobayashi, S. Katsura, and K. Ohnishi, “An Analysis of Parameter Variations of Disturbance Observer for Motion Control,” IEEE Transactions on Industrial Electronics. Vol.54, No. 6, pp. 3413-3421,2007.
[80] T. Yoshikawa, ''Classical Control Theory,Shokodo. 2004 (in Japanese).
[81] Y. Mori, “Control Engineering,” Corona Publishing. 2001 (in Japanese).
[82] S. Bolognani, L. Tubiana, and M. Zigliotto, “Extended Kalman Filter Tuning in Sensorless PMSM Drives,” M IEEE Transactions on Industy Applications. Vol.39, No. 6, pp. 1741-1747, 2003.