Quadruped robot

build and simulate a walking four-legged robot

Motivation

A four-legged Quadruped robot inspired by the Boston Dynamics Spot and MIT Cheetah, a project undertaken by Team Robocon BITS Pilani. Quadruped robots have several applications like last mile delivery, as guiding robots for visually challenged idividuls, surveillance, accessing hazardous enviornments and space exploration.

The Quadruped robot community and research is growing everyday in different parts of the world. Legged robots have several advantages over wheeled counter-parts in terms of traversibility. This also makes it an excellent research platform for legged locomotion, RL, perception, controls and dynamics. With this motivation this project was taken up to simulate a walking Quadruped in Gazebo ROS.

Simulation

Gazebo ROS simulation with trot gait.
Gazebo ROS simulation with pace gait.

Gait

This is how various gaits look like in a simple 2D animation.

   
Light Blue : Left legs
Dark Blue : Right Legs
Trot gait (left), walk gait (right)
Gallop gait (left), bound gait (right)

Kinematics

The calculations for inverse kinematics have been shown in the image below

Inverse Kinematics figure-1. [modified version, original image credits: a Spotmicroai community member]
Inverse Kinematics figure-2. [modified version, original image credits: a Spotmicroai community member]
Inverse Kinematics figure-3. [modified version, original image credits: a Spotmicroai community member]

References

  • Original idea : MIT Cheetah and Spot by Boston Dynamics
  • High speed trot-running: Implementation of a hierarchical controller using proprioceptive impedance control on the MIT Cheetah
  • https://github.com/mike4192/spotMicro
  • Spot mini mini : authors - Maurice Rahme and Ian Abraham and Matthew Elwin and Todd Murphey spotminimini2020github
  • Spot Micro AI Community : https://spotmicroai.readthedocs.io/en/latest/