This study was inspired by the human motor control system in its ability to
accommodate a wide variety of motions. By contrast, the biologically inspi
red robot learning controller usually encounters huge learning space proble
ms in many practical applications. A hypothesis for the superiority of the
human motor control system is that it may have simplified the motion comman
d at the expense of motion accuracy. This tradeoff provides an insight into
how fast and simple control can be achieved when a robot task does not dem
and high accuracy. Two motion command simplification schemes are proposed i
n this paper based on the equilibrium-point hypothesis for human motion con
trol. Investigation into the tradeoff between motion accuracy and command s
implification reported in this paper was conducted using robot manipulators
to generate signatures. Signature generation involves fast handwriting, an
d handwriting is a human skill acquired via practice. Because humans learn
how to sign their names after they learn how to write, in the second learni
ng process, they somehow learn to trade motion accuracy for motion speed an
d command simplicity, since signatures are simplified forms of original han
dwriting. Experiments are reported that demonstrate the effectiveness of th
e proposed schemes. (C) 2000 Elsevier Science B.V. All rights reserved.