An upper-body exoskeleton with a novel shoulder mechanism for assistive applications

A Review on Design of Upper Limb Exoskeletons

“…Bai et al [40] presented a four-DOF upper-limb exoskeleton with a novel shoulder mechanism for assistive applications. The unobtrusive feature of this exoskeleton is the double parallelogram (DPL) spherical mechanism, which was designed to support 3-DOF shoulder GH movements.…”

“…The exoskeleton structure with the DPL mechanism can actively support the shoulder extension/flexion and shoulder abduction/adduction, whereas the shoulder rotation was kept passive, which limits its use for several applications. Upper-limb exoskeleton research prototype: (A) parallel actuated shoulder exoskeleton adopted from Reference [41], (B) cmpliant robotic upper-extremity eXosuit (CRUX) adopted from Reference [42], (C) upper-limb exoskeleton for inferno adopted from Reference [43], (D) UB-EXO developed by Aalborg University [40], (E) compact 3 degrees of freedom (DOF) scissors linkages for upper-limb exoskeleton adopted from Reference [44], (F) NESM adopted from Reference [45], (G) Stuttgart Exo-Jacket adopted from Reference [46], and (H) CAREX 7 adopted from Reference [47].…”

“…Impedance control is a model-based force controller with position feedback. Bai et al [40] used an impedance control for a 4-DOF upper-limb exoskeleton to improve human-robot interaction that helps to regulate the user manipulation and traction forces.…”

“…Electric actuators are mostly adopted due to their straightforward approach to store electrical energy, and they are fairly capable in providing greater controllability using advanced motion control [40,46,130,131]. A few researchers [132] contend that electric actuators are as quite substantial, contrasted with their pneumatic counter part, and that their impedance is too high to be in any way utilized as a part of rehabilitation applications.…”

“…There are very few studies that have critically analyzed and taken into account the effect of shoulder girdle movement while designing a robotic exoskeleton that can support the 3-DOF shoulder GH joint. For example, References [6,40,41,67,75] have investigated the effect of shoulder girdle movements in designing an exoskeleton robot for the human upper limb. If the researches tried to overlook this effect, which they have done in some classified applications, it tends to limit the safer ROM.…”