T=0.63 (s), V=0.07 (m/s)



As a lateral perturbation, an impulse of approx. 0.56 (Kgm/s) that pushed the center of the body to the right was applied by a pendulum at the timing where only left foreleg was in the swing phase.



The reason why Kotetsu fell down by a lateral perturbation:
where LF, LH, RF and RH mean left foreleg, left hind leg, right foreleg and right hind leg, respectively. The suffix st and sw mean the stance phase onset and the swing phase onset, respectively.


After impact, correct phase transitions (LF-st, RH-sw, RF-sw, RH-st, RF-st, LH-sw) were followed.

But LF-sw was not followed since ACMexc was not employed. That is, the leg load of LF kept high and never became less the nominal threshold (X^LO). As a result, the stance-to-swing phase transition of LF was not triggered.

Consequently, the disorder of the gait began, and Kotetsu started to fall down while incorrect phase transitions (LH-st, RH-sw, RH-st, LH-sw, LH-st) being followed.

Finally, Kotetsu fell down to left-forward even though it had been pushed to the right.

WMV 3M