Towards Foot-Drop Correction using a Simulation of Bio-inspired Robotic Legs

Humanoids’ Feet: State-of-the-Art & Future Directions

“…Structure refers to the physical structure of the foot. Most humanoids adopt flat feet consisting of a unique rigid segment or of two rigid segments joined by a revolute joint [31][32][33][34][35][36][37][38][39][40][42][43][44][45][46][47][48][49][50][51]. One humanoid robot adopts a different solution with a unique rigid segment with a wheel on the foot [41].…”

“…With this joint, H6 [42,43] can move forward with its knees in contact with the ground. Eldirdiry et al provide a robotic foot with a passive joint and try to avoid foot drop [36][37][38][39][40]. Takahashi et al proposed an active joint in the foot for the first time and implemented it in the robot Ken [31].…”

“…2. Robotic feet with a one segment structure, with one segment with a wheel or with two segments structure (a) WL-12RVII [5,6], (b) CASSIE [7,8], (c) WABIAN-2R (unique-segment mechanism) [9], (d) BHR-2 [10][11][12], (e) HRP-2 [13,14], (f) WALK-MAN [15], (g) P2 [16], (h) HRP-4 [17,18], (i) KHR-3 [19,20], (j) PYRENE (TALOS) [21], (k) JAXON [22], (l) VALKYRE [23,24], (m) NAO [25][26][27][28], (n) ASIMO [29,30], (o) Ken [31], (p) ROBIAN [32,33], (q) iCub [34], (r) WABIAN-2R (two-segments mechanism) [35], (s) [36][37][38][39][40], (t) DRC-HUBO+ [41], (u) H6 [42,43], (v) UT-µ2 [44], (w) BIPMAN [45], (x) PNEUMAT-BH [46,47], (y) HRP-4C [48], (z) ARMAR-4 [49], (aa), LOLA [50,…”

“…In fact, the realization of single toe support makes walking more human-like. Some of these robotic feet consist of two rigid rectangular parts connected by a passive joint, which allows the pitch toe rotation [31][32][33][34][35][36][37][38][39][40]. The front rectangular part represents the toes following human-like inspiration, to address stability reproducing heel-contact and toe-off motion during walk.…”

“…When the foot structure does not include joints, only the ankle is actuated . Most of the articulated feet are equipped with passive internal joints [31][32][33][34][35][36][37][38][39][40][41][53][54][55]. However, some robotic feet have active joints: motors or other kinds of actuators like artificial muscles can independently move parts of the foot [42][43][44][45][46][47][48][49][50][51][52][58][59][60][61][62][63].…”