Syropod High-level Controller

Syropod High-level Controller (SHC) is a versatile controller capable of generating body poses and gaits for quasi-static multilegged robots. This ROS package implemented in C++ can be easily deployed on legged robots with different sensor, leg and joint configurations. SHC is designed to generate foot tip trajectories for a given gait sequence, step clearance, step frequency and input body velocity. Input sensors such as IMU and joint effort feedback can be utilised by the controller to provide robust trajectories even in inclined and uneven terrain. SHC was developed at CSIRO’s Robotics and Autonomous Systems Group to support its ongoing legged robot locomotion research. It is now being released as an open-sourced package, along with tutorials, for the benefit of the wider community as OpenSHC. The banner image and the video clip below shows a number of CSIRO's legged robots running SHC.

Getting Started

If you haven't looked at the tutorials for using OpenSHC, see OpenSHC Tutorials.

Please refer to the readme in the launch folder of individual platforms for information on setting up the platform for use with OpenSHC.

Video overview of OpenSHC:

Requirements

Ubuntu 18.04 LTS and ROS Melodic; or
Ubuntu 20.04 LTS and ROS Noetic

Dependencies

OpenSHC requires a robot specific configuration and launch repository such as Bullet Syropod to run. Please refer to that readme for more information.

Installation

mkdir -p openshc_ws/src
cd openshc_ws/src
git clone https://github.com/csiro-robotics/syropod_highlevel_controller.git
cd ..
catkin build

Publications

The details of OpenSHC is published in the following article:

B. Tam, F. Talbot, R. Steindl, A. Elfes and N. Kottege, "OpenSHC: A Versatile Multilegged Robot Controller," in IEEE Access, vol. 8, pp. 188908-188926, 2020, doi: 10.1109/ACCESS.2020.3031019.

How to cite

@article{tam2020openshc,
    author={Benjamin Tam and Fletcher Talbot and Ryan Steindl and Alberto Elfes and Navinda Kottege},
    title={OpenSHC: A Versatile Multilegged Robot Controller},
    journal={IEEE Access},
    year={2020},
    volume={8},
    number={},
    pages={188908-188926},
    doi={10.1109/ACCESS.2020.3031019}
}

Features

Fully configurable for a variety of platform designs with differing physical characteristics, including up to eight legs each with up to 5 degrees of freedom.
Four dynamically switchable gait options (Wave, Amble, Ripple and Tripod) plus ability to easily design custom gaits. (see config/readme.md)
User defined body clearance, step clearance and step frequency.
Manual body posing in 6 degrees of freedom.
Manual leg manipulation - select up to two legs simultaneously and toggle manual manipulation of either tip position in Cartesian space or direct control of joint positions (3DOF legs only).
Choice between two modes of start-up:
- Direct mode which move leg tip positions linearly from initial position to default walking stance positions.
- Full chain of start-up/shutdown sequences which allow a Syropod to start from a 'packed' state and generate a sequence to stand up off the ground into its default walking stance. Similarly able to shut-down and transition back to a packed state.
Optional impedance controller with dynamic leg stiffness to ensure leg contact with ground and offer a degree of rough terrain walking ability.
Optional IMU body compensation which uses IMU data to keep body horizontally level at all times.
Optional inclination compensation which strives to keep body centre of gravity over the estimated centre of support whilst walking on inclined planes.
Optional bespoke automatic body posing system which poses each robot leg cyclically as defined by auto-pose parameters. (see config/readme.md)
Cruise control mode which may either force a constant predefined input velocity for the Syropod or set the current input velocity as constant.
Auto navigation mode which when combined with the correct sensing capabilities and running syropod_auto_navigation node, give autonomous navigation with obstacles avoidance to an input waypoint.

Config Files

For information on parameters see readme.md in config folder.

Nodes