RAMIEL: A Parallel-Wire Driven Monopedal Robot

for High and Continuous Jumping

  • Temma Suzuki
  • Yasunori Toshimitsu
  • Yuya Nagamatsu
  • Kento Kawaharazuka
  • Akihiro Miki
  • Yoshimoto Ribayashi
  • Masahiro Bando
  • Kunio Kojima
  • Yohei Kakiuchi
  • Kei Okada
  • Masayuki Inaba
  • JSK Robotics Laboratory, The University of Tokyo, Japan

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.

Overview of Parallel Wire-driven Leg

The parallel wire-driven leg structure consists of a body part and a leg part which has one DoF of linear motion and two DoFs of rotation relative to the body part. The joints of the leg are controlled by six wires extending from the main body. Each wire is wound by an independent electric motor, and the target leg posture is realized by adjusting the winding length of the wire.

Hardware Design

To verify the jumping performance of the parallel wire-driven leg structure, we have designed and built a monopedal robot RAMIEL. RAMIEL is a robot with a height of 1.07 m, a width of 0.55 m, and a weight of 9.8 kg. RAMIEL can be roughly divided into two parts: the leg and the body. The body part consists of an outer shell as the frame, a gimbal module connecting the body and the leg, landing legs as grounding points when the body touches the ground, and High Power Wire Modules controlling the wires.

Electronic Components and Systems

In order to achieve a high jump, RAMIEL employs a high-power motor drive system with a maximum output of 3.5 kW. Furthermore, to realize agile maneuvers such as consecutive jumping, a high-speed internal communication system has been implemented.

Hopping Controller

We have developed a hopping controller for RAMIEL.

High Jump Experiment (0.7 m)

RAMIEL can jump 0.7 m and land successfully.

High Jump Experiment (1.6 m)

RAMIEL achieves a maximum jumping height of 1.6 m, failed to land.

Continuous Jump Experiments

RAMIEL performed 7 consecutive jumps from seated position and succeeded in landing.

Bibtex

  @inproceedings{suzuki2022ramiel,
    title={RAMIEL: A Parallel-Wire Driven Monopedal Robot for High and Continuous Jumping},
    author={Suzuki, Temma and Toshimitsu, Yasunori and Nagamatsu, Yuya and Kawaharazuka, Kento and Miki, Akihiro and Ribayashi, Yoshimoto and Bando, Masahiro and Kojima, Kunio and Kakiuchi, Yohei and Okada, Kei and others},
    booktitle={2022 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)},
    pages={5017--5024},
    year={2022},
  }

Contact

If you have any questions, please feel free to contact Temma Suzuki (gmail: t-suzuki @ jsk.imi.i.u-tokyo.ac.jp).