  Legged robots with high locomotive performance have been extensively studied,
and various leg structures have been proposed. Especially, a leg structure that
can achieve both continuous and high jumps is advantageous for moving around in
a three-dimensional environment. In this study, we propose a parallel
wire-driven leg structure, which has one DoF of linear motion and two DoFs of
rotation and is controlled by six wires, as a structure that can achieve both
continuous jumping and high jumping. The proposed structure can simultaneously
achieve high controllability on each DoF, long acceleration distance and high
power required for jumping. In order to verify the jumping performance of the
parallel wire-driven leg structure, we have developed a parallel wire-driven
monopedal robot, RAMIEL. RAMIEL is equipped with quasi-direct drive, high power
wire winding mechanisms and a lightweight leg, and can achieve a maximum
jumping height of 1.6 m and a maximum of seven continuous jumps.
