SEARCH WITHIN CONTENT
Citation Information : International Journal on Smart Sensing and Intelligent Systems. Volume 5, Issue 2, Pages 458-486, DOI: https://doi.org/10.21307/ijssis-2017-490
License : (CC BY-NC-ND 4.0)
Received Date : 20-April-2012 / Accepted: 09-May-2012 / Published Online: 01-June-2012
Power assist robots are usually used for disabled and elderly people to augment their abilities and skills. This paper proposes to use these robots to handle heavy objects in industries, and thus brings a novelty in the applications of power assist robots. However, it is difficult to optimize perceived heaviness and motion either independently or simultaneously for lifting objects with power-assist. Hence, this paper investigates the techniques to optimize perceived heaviness and motion following bionic and psychophysical approaches. We developed two systems-one was used to lift objects manually, and another was a power assist system to lift objects with it. Several hypotheses and strategies related to weight perception and time constant were adopted. Humans lifted objects manually and with power-assist independently. Analyses showed that load force rate for power-assisted lifting were lower than that for manual lifting. We hypothesized that time constant of the assist system might be responsible for this. We changed time constant and found that increase in time constant reduced perceived heaviness and load force. Then, objects were lifted with power-assist in some selected conditions pertaining to time constant. Analyses showed that perceived heaviness was related to load force rate while object motion (acceleration) was related to load force magnitude. It was then demonstrated how to independently optimize perceived heaviness and motion by optimizing load force rate and its magnitude respectively. Techniques for simultaneous optimization of motion and perceived heaviness were also presented. Finally, we proposed to use the findings to develop power assist robots for manipulating heavy objects in industries that may enhance interactions with humans in terms of maneuverability, safety etc.
H. Kazerooni, “Extender: a case study for human-robot interaction via transfer of power
and information signals,” in Proc. of 1993 IEEE International Workshop on Robot and
Human Communication, pp.10-20.
H. Seki, K. Ishihara and S. Tadakuma, “Novel regenerative braking control of electric
power-assisted wheelchair for safety downhill road driving,” IEEE Transactions on
Industrial Electronics, Vol. 56, No. 5, May 2009, pp. 1393-1400.
K. Kong, H. Moon, B. Hwang, D. Jeon, M. Tomizuka, “Impedance compensation of
SUBAR for back-drivable force-mode actuation,” IEEE Trans. on Robotics, Vol. 25,
No.3, 2009, pp.512 – 521.
T. Kawashima, “Study on intelligent baby carriage with power assist system and
comfortable basket,” Journal of Mechanical Science and Technology, Vol.23, No.4, April
 T. Tanaka , Y. Satoh, S. Kaneko, Y. Suzuki, N. Sakamoto and S. Seki, “Smart suit: soft
power suit with semi-active assist mechanism – prototype for supporting waist and knee
joint,” in Proc. of 2008 Int. Conf. on Control, Automation and Systems, pp. 2002-2005.
G.Liu, Y. Yan, J. Chen, T. Na, “Simulation and experimental validation study on the drive
performance of a new hydraulic power assist system,” in Proc. of 2009 IEEE Intelligent
Vehicles Symposium, pp.966-970.
S. Lee, S. Hara, Y. Yamada, “Safety-preservation oriented reaching monitoring for
smooth control mode switching of skill-assist,” in Proc. of 2008 IEEE Int. Conf. on
Systems, Man and Cybernetics, pp.780–785.
K.Kosuge, H. Yabushita, Y. Hirata, “Load-free control of power-assisted cycle,” in Proc.
of the First IEEE Technical Exhibition Based Conf. on Robotics and Automation, 2004,
M. Ding, J. Ueda, T. Ogasawara, “Pinpointed muscle force control using a power-assisting
device: system configuration and experiment,” in Proc. of 2008 IEEE Int. Conf. on
Biomedical Robotics and Biomechatronics, pp.181 – 186.
K. Osamura, S. Kobayashi, M. Hirata, H. Okamoto, “Power assist control for slide
doors using an ideal door model,” in Proc. of 2008 IEEE Int. Symp. on Industrial
Electronics, pp. 1293 – 1299.
S.M.M.Rahman, R. Ikeura, S. Hayakawa, H. Sawai, “A critical look at human’s bimanual
lifting of objects with a power assist robot and its applications to improve the power-assist
control,” in Proc. of 2010 IEEE Int. Conf. on Robotics and Biomimetics, Dec. 14 -18,
M.M.Ayoub, “Problems and solutions in manual materials handling: the state of the art,”
Ergonomics, Vol. 35, Issue 7 & 8, July 1992, pp. 713 – 728.
A.M.Okamura, A. Smaby, M.R. Cutkosky, “An overview of dexterous manipulation,”
in Proc. of IEEE Int. Conf. on Robotics and Automation, pp. 255-262, 2000.
P.T.A. Nguyen, S. Arimoto, “Dexterous manipulation of an object by means of multi-
DOF robotic fingers with soft-tips,” Journal of Robotic Systems, Vol.19, No. 7, pp. 349-
A. Niinuma,T.Miyoshi, K. Terashima,Y. Miyashita, “Evaluation of effectiveness of a
power-assisted wire suspension system compared to conventional machine,” in Proc. of
2009 IEEE International Conference on Mechatronics and Automation, pp.369-374.
T.Takubo,H. Arai,Y.Hayashibara,K. Tanie,“Human-robot cooperative manipulation using
a virtual nonholonomic constraint,” Int. J. of Robotics Research, Vol.21,No.5, 2002,
pp.541 – 553.
T.Doi, H. Yamada, T. Ikemoto, and H. Naratani, “Simulation of a pneumatic hand crane
power-assist system,” Journal of Robotics and Mechatronics, Vol.20, No.6, 2008, pp.
S.M.M.Rahman, R. Ikeura, M. Nobe, H. Sawai, “Design of a power assist system for
lifting objects based on human’s weight perception and changes in system’s time
constant,” in Proc. of the 2nd IEEE International Conference on Human System
Seki,H.,Iso,M.,Hori,Y, “How to design force sensorless power assist robot considering
environmental characteristics-position control based or force control based-,”in Proc. of
Annual Conf. of IEEE Industrial Electronics Society,Vol.3,pp.2255-2260,2002.
S.M.M.Rahman, R. Ikeura, M. Nobe, H. Sawai, “Displacement-load force-perceived
weight relationships in lifting objects with power-assist,” in Proc. of SPIE, Vol. 7500,
S.M.M.Rahman, R. Ikeura,S. Ishibashi, S. Hayakawa, H. Sawai, “Understanding the
reasons for which power-assist-lifted weight is 40% of actual weight: the preliminary
studies,” in Proc. of 2010 IEEE Int. Symp. on Micro-NanoMechatronics and Human
S.M.M.Rahman, R. Ikeura, M. Nobe, H. Sawai, “Human operator’s weight perception of
an object vertically lifted with a power assist system,” in Proc. of 2008 IEEE/SICE
International Symposium on System Integration, pp.24-29.
L.A. Eric, and D.J. Woodrow, “The role of rotational inertia in the haptic and haptic +
visual size-weight illusions,” Ecological Psychology, Vol.15, No.4, 2003, pp.317 – 333.
J.S.Chen, Y.K.Huang, C.C.Cheng, “Mechanical model and contouring analysis of highspeed
ball-screw drive systems with compliance effect,” Int J Adv Manuf Technol,
J.R.Flanagan, M.C.Bowman, and R.S.Johansson, “Control strategies in object
manipulation tasks,” Current Opinion in Neurobiology, Vol. 16, No.6, 2006, pp.650-659.
A.M.Gordon, H.Forssberg, R.S. Johansson, and G.Westling, “Visual size cues in the
programming of manipulative forces during precision grip,” Experimental Brain
Research, Vol. 83, No.3, 1991, pp. 477–482.
S.M.M.Rahman, R. Ikeura, M. Nobe, H. Sawai, “Controlling a power assist robot for
lifting objects considering human’s unimanual, bimanual and cooperative weight
perception,” in Proc. of 2010 IEEE Int. Conf. on Robotics and Automation, pp.2356-2362.
S.M.M.Rahman, R. Ikeura, M. Nobe, H. Sawai, “Harmonic motion analysis and control
for manipulating objects with a power assist robot based on human characteristics,” in
Proc. of 2010 IEEE Int. Conference on Biomedical Robotics and Biomechatronics,pp.33-
S.M.M.Rahman, R. Ikeura, M. Nobe, H. Sawai, “Human’s weight perception and load
force characteristics in lifting objects with a power assist robot,” in Proc. of 2009 IEEE
Int. Symposium on Micro-NanoMechatronics and Human Science, pp.535-540.
J.R.Flanagan, and M.A. Beltzner,“Independence of perceptual and sensorimotor
predictions in the size-weight illusion,” Nature Neuroscience, Vol.3, No.7, 2000, pp.737-
H.Kobayashi, R. Ikeura, H.Inooka, “Evaluating the maneuverability of a control stick
using electromyography,” Biological Cybernetics, Vol. 75, No.1, 1996, pp.11-18.
H. Kato, R. Ikeura,S. Noguchi, K. Mizutani, H. Nakamura and T. Honda, “Impedance
control for an industrial power assist device considering contact operations,” Transactions
of the Japan Society of Mechanical Engineers, Series C,Vol.72,No.714,2006, pp.214-
R. Ikeura, “Dynamic characteristics of human and support system,”Journal of the Society
of Instrument and Control Engineers, Vol.45, No.5,2006, pp.413-418. [In Japanese].
R. Ikeura, H. Hoshino,D.Yokoi, Y. Kanehara,H. Hoshino,K.Mizutani,H. Sawai, “A rating
method for the vehicle steering based on the impedance of human arms,” Transactions
of Society of Automotive Engineers of Japan,Vol.37,No.4, 2006, pp.33-38. [In Japanese]
 R. Ikeura, H.Inooka, K.Mizutani, “Subjective evaluation for maneuverability of a robot
cooperating with humans,”J of Robotics and Mechatronics, Vol.14, No.5, 2002, pp. 514-
 H. Kobayashi, R. Ikeura, H.Inooka,“Evaluation of maneuverability using
electromyography in manual tracking control,” Japanese Journal of Ergonomics,Vol.34,
No.2, 1998, pp.89-95. [In Japanese].
S. Hara, “A smooth switching from power-assist control to automatic transfer control and
its application to a transfer machine,” IEEE Trans. on Industrial Electronics, Vol. 54, No.
1, 2007, pp.638-650.
H. Kazerooni, “Exoskeletons for human power augmentation,” in Proc. of IEEE/RSJ Int.
Conf. on Intelligent Robots and Systems, pp. 3459 – 3464, 2005.
T. Hayashi, H. Kawamoto, Y. Sankai, “Control method of robot suit HAL working as
operator's muscle using biological and dynamical information,” in Proc. of 2005
IEEE/RSJ Int. Conf. on Intelligent Robots and Systems, pp. 3063 – 3068.
 J.R. Flanagan, S. King, D.M. Wolpert, R.S. Johansson, “Sensorimotor prediction and
memory in object manipulation,” Canadian Journal of Experimental Psychology, 2001,